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lh\s invention relates to sjtz>rage and in prefc^rred embodiments relates to the art of cold storage, including applianoes wdti as refrigc«^t3ors and freezers for storing foodstuffs and other pari£^t)tes. Oth^ applications of ^B invention include storage of chemical and medical or tnological specimens. The invention also finds use in mobile applications, for example in the transport and storage of perishable goods. More generally, tiw invention finds use in any form of storage involving the use of drav^ers, and especially where the drawers carry heavy loads and need to be seated when closed.
The invention develops and adds to the various features of the Inventor's copending International Patsnt Api^ication No. ^CI/6BQQ/Q35Zl published as WO 01/Z0Z37, the content of which is inoorporatad Kerein by reference. The invention is also derived from UK Patent Application No. OJjQfidi^ put>lished as GB Z367353| the content of which is also incorporated herein by reference and from which, inter aim, the present app(icatk>n cteims priority. As in those specifications, the invention can tn applied to storing any items within a cooled environment, such as in a refrigerated goods vehicle. The term ^appliance' is therefore to be construed broadly, extending beyond fixed domestic devices into industrial, scientific and mobile applications. However, this specification will particularly describe domestic or commercial oold-stDrage applianoes for storing foodstuffs,
'^ ^ wipfly to recap the introduction of WO 01/Z0237, the advanteges of storing ; '• fcrodstuffs and other perii^ble items in r^^raHgETand segregated conditions have long been known: refrigeration reterds the degradation of such iten^ and segregation helps to prevent their cross-oontemination. Accordingly, modem cold-storage appliances such as refrigerators and freezers are usually compartmentetised, albeit x\
The inventlQn herein and the inventions in WO 01/20237 and GB 2367353 were devised against a background of typical cold-storage appliances, most of which comprise one or more upright cabinets each vfith a vertically-sealed hinged door on its front. Substantially all of the intBrior of the cabinet defines a storage Yolumei most commonly partitioned by shelves or drawers for supporting stored foodstuffs. Acc€£S to aU of the shelves or drawers in the cat^ncA; is gained by opening the door,
A cooler unit generates a convection loop within the cabinet, in which air cooled by the cooler unit sinks toward the bottom of the catnnet and as that air at)sort3s heat during its downward ioumey, it warms and rises buck up to the cooler unit where it is cooled again. It is also pos^bte to have forced-air circulation tyy means of a fan within or communicating with the catMnet Ihe e^lves or drawers are typically made of wire so that they offer little recnstance to this circulation of air.
Upright refrigerators and freezers are often comtnned arui sold as a single-cabinet bridge freezer' unit with a refrigerator occupying an upper compartment arul the freezer occupying a tower compartment, or vice versa. As different temperature are required for the two compartments, they are partitkmed by a solid divide and each compartment has its own door and cooler unit, conventionally in the form of an evaporator.
The domestic fridge freezer usually \^s only one compressor and the refrigerator evaporator is in series with the freeze evaporator. In that case, temperature control and measurement is usually confined to the r^rigerator compartment. Where temperature contrc^ is required in bc^ compartments, the evaporators are in parallel and have respective solenoid valves acMl temperature switches providing on/off cooling mass control to each compartment In either case, however, the
aim of maximising thair snargy •fRciancy.
The invention herein and the inventionf in WO 01/20237 end GB 2367353 were devised against a backgrourKi of typical cold-ctoraoe applianoes, most of which comprise one or more upright cabinttt each with a vertlcally-sealed hinged door on its firont. Substantially all of the interior of the cabinet defines a storage volume^ most commorUy partitioned by sheivas or drawers for supporting stored Foodstuffis. Access to ail of the shelves or drawers in the cabiruit is gained by opening the door.
A cooler unit generates a convection loop withbi the cabinet, in which air cooled by the cooler unit sinlct toward the bottom of the cabinet and at that air absorbs heat during its downward journey, it warms and rises back up to the cooler unit where It Is cooled again. It is also possible to have forced-air circulation by means of a fan within or communicating with the cabinet. The shelves or drawers are typically made of wire so that they offer little resistance to this circulation of air.
Upright refr-igerators and fireezers are often combined and sold as a single-cabinet 'fridge fireezer' unit with a refi'igerator occupying «i upper compartment and the freezer occupying a lower compartment, or vice versa. As different temperatures are required for tfie two compartments, they are partitioned by a sotM divide and each compartment has its own door and cooler unit, conventtonally in the form of an evaporator.
The domestic fi'idge ftwmts usually has ortly one oomprassor and the refrigerator evaporator is in series with the freezer evaporator. In that case, temperature control and measurement is usually confined to the refi'igerator compartment. Where temperature control is required in both compartments, the evaporators are
freezsr, which sp«c« must bm pr«Mrv«d to allow Itt lid to b« opwiod. Ev«n if a sliding lid is usad InstMd of an upwardiy-optning tid, Itams cannot b« laft conveniently on top of tha lid. It is also wall known that large chest freezers can malce access to their contents axtramaiy difncuit, It being necessary to stoop down and shift numerous heavy and palnfUlly cold itams to gat to items at the bottom of the freezer compartment.
Finally, the present invention and _W
Conventional cold-storage appliances axamplifiad by upright refrigerators and chest freezers are not tl^ only prior art dlscioswes of interest. For example, It has been known for many years to dlvkia a rafrigarator Into compartments, each with its own dedicated door or lid. Examples of this Mea are disclosed In UK Patent Nos. GBJ02j590^^GB §tU12I and GB 579^7I«^ ill to Earia« that describe cabinet-like refrigerators.
In those Earie documents, tha front of tha cabinet is provided with a plurality of rectangular openings for receiving d-awers. Each drawer has a front panel larger than its respective opening so that a varticai seal Is formed around the overlap when the drawer is bi a dosed positkNi. Tha drawers end their contents are cooled
by a cooler unit that drcuiatvs COOIMI air by oonv«ction within th« cabinet, in common with tha typas of rtfrigtrator already dtsailMid. To promote circulation of this air amongst all of the drawers^ the drawers ere open-topped end have apertures in their bottoms. Also, the drawers are disposed in a stepped arrangement, those at the top of the refirlgerator extending back less l^r into the cabinet than the lower drawers so that the n&r of each drawer Is exposed to the downward flow of cooled air from the cooler unit
Although only one drawer need be opened at i time, the apertures in the bottom allow cold air to flow freely from the open drawer, which is replaced by warm moist ambient a^ to the (tetrftnent of energy efficiency and with the inaeased possibility of aoM-contaminatlon. Indeed, when a drawer is opened, cold air within the cabinet above the level of that drawer will flood out; drewing ambient air into the cabinet. Furthermore, the (frawert encourage ambient air to flow into the interior of the refrigerator because, upon opening, they act as pistons drawing the ambient air' into die interior of the refrigerator cabinet. Once in the cabinet, the warm air can cfa^oulate es freely as the cold air that is supposed to be there.
Even when closed, the eccumuiation of cold air towards the bottom of the cebinet wlil exert Increased pressure on the vertical seals of the lowest drawers, increasing the likelihood of leakage if the seal Is faulty.
A further example of the above type of refrigerator Is disclosed in UK Patent No. GBi>02,3294 also to Eerie. The refrigerator disck>sed therein suffers many of the above problems but is of greater Interest In that a single drawer consisting of insulated sides and base is provkled within the oooied interior of the cabinet. In contrast to the variants outlined above, the sides and base are solid and not perforated so that air cannot fk>w through them. Wlien the drawer is closed, a
horizontal m«mb«- within the cibiMt oombiMS with th« dr«w«r to d«fin« a compartment, the horizontal member thus being a lid for the drawer. This compartment is provided with its own cooling coils situated just below the horizontal member.
Very little detail is given about the seal that is formad between the drawer and the horizontal member, other than that the horizontal member has a downwardly projecting rear end with a biased edge that makes a close fit with the rear wall of the drawer. Nothing else Is said about the Junction batween the drawer and the horizontal member, apart firom the general statement that the drawer is adapted when In Its closed position to fit *f^lrly snugly' against the horizontal member. It can only be inferred that the drawer and the horizontal member merely abut against each other. Whilst this will impede the passage of air into and out of the drawer, it will not form an bnpervlous seat. As this is rwt a vapour seal, icing and cross-contam ination is tttcely to occur even when the drawer is closed.
The drawer arrangement desaK>ed aeatas a compartment in whidi a different temperature can be set when compared to the ossantially common temperature of the rest of the refrigerator. It is particularly envisaged that the drawer can act as a freezer compartment. The Applicant has appreciated a disadvantage In this arrangement, namely that as the fireezer drawer re^des within the cooled interior when closed, the outer surfeces of the (b'awer within the cabinet will be cooled to the temperature of the refirigerator. Accordingly, when the drawer is opened, those cooled outer surfiices will be exposed to ambient air containing moisture that will condense on the cooled surfaces toadbtg to vn undesirable accumulation of moisture. Condensation involves transfMr of latent heat fi^om water vapou* to the drawer, thus increasing die burden of cooling the drawer again when the drawer is returned to the closed position within the cabinet.
Additionally, condensad moisturt wiH b« transfiHTtd to th« intsrior of tha
r«frlgerator when th« dr«w«r is doMd. A* diaousstd abova, tha prtm)ic» of watar
promotas mlaoblai activity. A fUrthar disadyantaga of Introdudno watar Into tha
interior of the refrigerator Is that it may fraaza: this can be a particular problem
where the drawer of tha andosad compartment meats tha insulated top« as any
ice formation will form a seal that lodes tha drawer in a permanently closed
position. In fact, tha of ice formation is due to moisture migration across the
Interface between the drawer and tha top. This disadvantage was appreciated by
Earle, as a cam mechanism is mantjoned in (SB 602jX^^ any ice formed at
the seals or on the rimners or other support surfteas of the drawers. It is also possible for a build-up of ice to affect tha SMiIng ability of the seal, by preventing mating sealing surfaces from mating correctly. Of course, tha accumulation of ice on moving parts of the drawer mechanism is also undesirable as It will impede movement of the drawer.
A further interesting prior art document, cited as technological background against WOjgi/202aL .iiJJ!S.Pit«it No. 1,3174&96 to Ewan. Ewan speaks of segregation between refrigerated drawers contained In a surrounding cabinet and employs refrigerating units placed 'immediately arul dosaly above each drawer... so that said drawer may In affict ba saM to ba dosad against saM refrigerating unit*, l-iowever, there has to ba a gap left between the cfa'awer and tha refrigerating unit If the drawer is going to open. As In Earia, that gap will promote Icing as moist air within the cabinet migrates into the drawer and the watar vapour condenses and freezes. The smaller tha gap, tha sooner tha accumulating lea will prevent drawer movement If a Iwger gap is tried Irwtead, there will be a greater spillage of air and hence the refrigerator will ba less arMurgy-afRclent and more susceptible to cross-contam ination.
That aside« the spitlag* of cold air in Ew«n iowars the tsmparaturs within the cabinet around th« drawer*, and to incraasaa the M(alt)ood of condensation on the drawers when opened. It will be noted that cold air spilled in this way can fiall freely behind the drawers within the cabinet and so expose the exterior of the drawers to air substantially below ambient temperature. Certain design details of Ewen worsen this eflect. For example, the bottom wall of the Ewen unit is an efficient insulator which will ^gnificently reduce the surface temperature of the drawers. Also« the internal divisions between the drawers do not allow for ambient heat transfer to the drewers but only for heat transfw between the drewers, thus promoting drawer>to-drawer temperature equalisation over time. Left for long periods, or even overnight, large perts of the external sur^Ke of each drawer wilt fall to temperatures significantly below ambient dew point. Condensation or ice will therefore form on those surfoces as soon as the drawers 9r9 opened; similarly, if the drawers are removed and left outside the appliance, ti\ey will start to *sweat' with condensation.
Lilce Earie, opening and dosing a drawer within a sMiad cabinet in Ewen acts like a piston, alternately applying both negative and positive pressures to adjacent areas. This promotes ata* trans^ through die drawer opening at the front of the cabinet, which can displace cold treated air In a drawer, and within the cabinet itself. An over-sized cabinet would reduce the piston effect but would elso be wasteful of space. Conversely, a more space^fflcient ciote«fitting cabinet may deaease the displacement of cold treated air, and eo reduce the burden of cooling the warmer air that taices its place, but it will increasa resistance to opening and closing the drawer.
Cold air pillage aitide^ the gap inevitably left between a drawer and its associated
lid In prior art arrangtmtntt It largt tnough to illow tht p«««g« of cnzymes; sporos and othar airborna contaminants. Also, Ewan disdosas a common intarconnacting drain and this too would allow fraa transftr of contaminants batwaan aach drawar, particularly undar tha afbraipantionad piston action.
Whilst Ewan spaaks of diffiarant tamparaturas in difliarant drawars, tha plurality of cooling lids ara connactad in serias and hava no maans for indhriduai tamparatura control in aach drawar. Tha diflarant tamparaturas ara daslgnad-in by providing soma drawers with mora cooling atanmts than othars, but thara is no maasuramant or control of thosa tamparaturas in usa. Also, lika tha com par tm ants of mora convantlonai prior art, aach drawar In Ewan has a flxad Hinctlon, namaly frsfizer or refirigarator.
Even If removed from tha applianca, Ewan's drawers will stay attached to their drawar fronts and runners. This does not land tha drawers to temporary storage or transport. Moreover, IHce Ewie, the drawers Hi Ewan cannot be opened fUiiy: they can only be opened less than half*way while being supported by the structure of the appliance. This is to the detriment of access to, and visibility and illumination of, tha contents.
It is against this badcground that tiie present invention has been devised.
From one aspect, the invention resides in a cotd-^torage appliance including: an open-topped insulating container defining an external sur^ce; an insulating lid adapted to close the open top of 0ie container; a cooling means adapted to cool tha interior of the container; and a structure supporting the container, the lid and the cooling maans; wherebi the container is mounted to the structure fbr movement relative to the structure and the lid to open the contairwr and afford
access to its interior or to close the contains, end wherein the lid is mounted to the structure for movement relative to the structure and the container to firee the container from the lid upon openbig or to bring the container and the tid together upon dosing.
Thus, in this aspect of the invention^ the lid moves to free the container for movement. In a simple arrangement that will be described, the lid can be tilted relative to the structure and the container. 1^ example, the lid can be hinged to the structure, the hinge prefiM'ably defining a pivot axis horizontally spaced from the container so that the lid is lifted fully ewey firom the container. More generally, it is preferred that the lid is movable transverse to the direction of movement of the container.
Beneficially, lid transport means are responsive to movement of the container or of a support means movable to sm>port the container durhig said movement. The iid tran^ort rrytn$ can move tfM lid befbre the container starts moving upon opening and after the container has stopped moving upon closing. In that case, where a support means is movable to support die container ckiring said movement, the iid transport means is prefwably between the support means and tlie iid and responds to movement of the si4>port means to move the iid.
The support means can be movable Independently of the container, In which case the iid tran^ort means can be re^Mnsive to relative movement between the support means and the container and mora particularly to continued movement of the support means after movement of the container iuw ceesed.
In an alternative arrangement, the lid trensport means moves the lid during initial movement of the containar upon opening and during final movement of the
container upon closing.
The invention also rwktes in a ooid-storaga appiianai indudino: an opan-toppad insulating contalnar defining an axtarnal surftca; an infulating lid adaptad to closa tha opan top of tlia contabMr; a cooling maans adaptad to cool tha intarlor of tine container; and a structure supporting the container, the lid and the cooling means; wherein the container is mounted to the structure for movement relative to the structure and the lid to open the container and afVbrd access to Its interior or to close tine container, and wherein said movement of the container inckjdes: a mjior component to open the oontainef and afford aooass to its interior or to close the container; and a minor oomponenl^ trensverae to the major component, to free the container from the lid at the t>eglrviino of said m^^or component upon opening or to bring the container and the lid together et the end of said major component upon dosing.
In this aspect of thm irwention, the two-oomponent movement of the container serves to clear the container from the lid. To avoid a wiping action on seals between the contairmr and the lid, it is preferred that the minor component talent to take place during initial movement in the direction of the m^jor oomporMmt upon opening and during final movement tn the direction of the major component upon closing.
In this aspect, it Is prtfiBrrad that a support means is movable to support the container during the major component end that container tren%>ort means is disposed between the support means and the container to responds to movement of the support means to efltect the minor component. Where the support meens is movable indepen(^tiy of the container, the oontabiw transport means can be responsive to relative movement between the support means and the container.
For instance, th« containv transport maans is prafivably rasponslva to continuad movemant of tha SL4>port maans altar tha m^Jw componant of movamant of tha container has been cmn plated.
The container transport maans suitably inckidts a first part in fixed relation to the support means and a second part in fixed relation to tha container, wherein relative movement between tha parts accommodates said continued movement of the support means. In this case, ralatlva movamant between tha parts causes the minor component of movemant of tha oontainar. For axwnple, one part can Include a ramp and the other part can include a ramp follower, sudi as a wheel. The ramp may further ba asaodatad with stops or buffiM's to limit relative movement of the rwnp follower.
Advantageously, the si^port mtans may also ba fixed to a stabilising mechanism to resist lateral sway of th% container during the m^Jor component of movement. That stabilising mechanism praforably includes pinions movable with the support means, the pinions being engaged with respectiva iatarally-spacad radcs extending In the direction of tha major componant.
In order that tha present invention can ba mora readily understood, reference will now be made, by way of example only, to tha aooompanying drawings In which: Figure I is a front view of a rafrigerator/flraazar appliance as disclosed in the Applicant's co-panding Intamationoi Patent Application No!^PCT/GB00/03521 (WO 01/20237), showing a vertical array of drawers each including a bin;
Figure 2 is a side view of the applianca of Figure 1, with a bwer portion of a side panel removed so that tha sides of tha drawers can ba seen;
Figure 3 is a section along iint III-III of Figure 2 but with tiie drawers closed;
Figure 4 is a section along line IV-IV of Figure 1;
Figure 5 is an enlarged schematic sectlonaS side view of two drawers of an appliance of the invention in which a lid is movable with respect to the structure to separate the lid from a bin, thereby allowing the bin to be moved subsequently in a single opening direction;
Figures 6(a) and 6(b) are partial sectional side views of an appliance in accordance with the invention, Figure 6(a) showing a drawer closed with Its bin sealed to a lid, and Figure 6(b) showing (in solid lines) the drawer partially open with the bin dropped vertfcaliy away from the lid, and then (in dashed lines) lUIIy open with the bin slid horizontally fbrward to afford access to its interior;
Figure 7 Is a front part-sectional detail view of a bin b'ansport mechanism being part of the appliance of Figures 6(a) and 6(b);
Figure 8 is a partial side view of a bin being part of the appliance of Figures 6(a), 6(b) and 7;
Figure 9 is detail side view of a wheel housing shown in Figures 6(a), 6(b) and 7;
Figures iO(a) and 10(b) are schematic detail side views of the wheel housing of Figure 9 in operation;
Figures U(a) and U(b) art sid« vitws of a cb'awar in accordanca with the invention, whidi is akin to that shown in Figuras 6(a) and 6(b) but has the added refinement of a lever that assists opening and closing of the drawer;
Figure 12 Is a schematic plan view within a drawer recess of an appliance adapted to receive a drawer of Figuras 6(a) and 6(b) or Figures 11(a) and I Kb);
Figures 13(a) and 13(b) are a plan view and a sectional side view respectively of a lid showing Its sealing* cooling and drainage feciltties in detail;
Figure 14 is a diagrammatic view of a pkrality of the lids of Figures 13(a) and 13(b), showing their separate drainage arrangements;
Figures 15(a) and 15(b) are a bottom plan viaw and a sactlonal side view respectively of a lid adapted for use in a fen coil cooling system;
Figures 16(a), 16(b) and 16(c) are front and side elevation views and an enlarged partial cross-sectional detail view of a bench>type cold-storage appliance having an alternative layout to that shown in Figures 1 to 4;
Figures 17(aX 17(b) and 17(c) are part-sactionai side, front and enlarged front views respectively of a further bbn transport mechanism, Figure 17(a) being on line Y-Y of F\gof 17(b) and Figures 17(b) and 17(c) being on line X-X of Figure 17(a);
Figures iQ{a), I9{p) «na le^c; ar« parc-s«cnofVii a«caii vraws or a wneei bracket attached to a transport piate« Figure 18(a) being a section on iine X-X of Figure 18(b), Figure 18(b) being a section on iine Y-Y of Figure 18(c), and Figure 18(c) being a plan view;
Figure 19 is a side view of a transport plate fitted with wheel brad
Figure 20 Is a side view of a bin support frame for use with the transport plate of Figure 19;
Figure 21 is a schematic detail side view of a wheel housing component being attached to the bin support frame of Figure 20;
Figures 22(a), 22(b), 22(c) and 22(d) are partial sectional side views showing tKe operation of the bin transport mechanism of Figures 17(a), 17(b) and 17(c), Rgure 22(a) ^K>w)ng the bin sealed and ^h% weight of tiie bin being carried on wheels, Figure 22(b) showing the bin released from its seals but with the weight of the bin stiti being cwried on wheels, Figure 22(c) showing engagement of a bin support frame and transport plate, and Figure 22(d) showing load transit to the transport plate such that the weight of ttie bin is carried on runrters as the bbi undergoes a horizontal opening movement;
Figures 23(a) and 23(b) are part-sectional side and front views respectively of another bin transport mechanism, employing sliding blocks, Figure 23(a) being on line Y-Y of Figure 23(b) and Figure 23(b) being on line X-X of Figure 23(a);
Figures 24(a}« 24(b} and 24(c} art partial sactional sida viaws showing the operation of the bin transport mechanism of Figwes 23(a) and 23(bX Figure 24(a) showing the bin sealed, Figure 24(b) showing the bin released from Its seals and Figure 24(c) showing engagement of a bin support frame and transport plate as the bin undergoes a horizontal opening movement;
Figure 25 is a part-sectional side view of a further bin transport mechanism taken on line Y-Y of Figure 26;
Figure 26 is a sectional view of the bin transport mechanism of Figure 25 tai
Figure 27 is a side view of a wheel ramp used in the bin transport median ism of Figures 25 and 26;
Figure 28 is a front view of a wheel assembly for use in the bin transport medianism of Figures 25 to 27;
Figure 29 is a sectional side view of the wheal assembly of Figure 28, talcen on line A-A of that Figure;
Figures 30(a) to 30(f) are a se
Figure 31 is a sectional side view of a damper for use in the bin transport m echanism of Figures 25 to 30;
Figures 32(a) to 32(f) ar* a aaquanoa of sactional std« viaws of an alternativa dampar for usa in tha bin bansport machanism of Figuras 25 to 30;
Figures 33(a) to 33(a) ara a saquanca of sactional side viaws showing the operation of a ^thiar aitarnativa bin transport machanism;
Figures 34« 35 and 36 ara side and front viawa raspactivaly of a restraining mechanism, tha fl'ont view of Figure 36 being talcan on line X of Figure 35; and
Figures 37(a) to 37(0 va a saquanca of aactionai side viaws showing the operation of a bin transport mad^anism biduding restraining mechanisms ^own in FiQurBS 34, 35 and 36.
Whilst the disclosure of tha Applicant's co-panding Intarnational Patent Application No. PCT/GB00/0352i (WO 01/20237) is incorporated herein by reference, Figures 1 to 4 of WO 01/20237 ar* raproducad in tha drawings appended to this specification and will now ba dasatt>ed to help put tha present invention into context.
Figures 1 to 4 show a rafirigerator/IVeezer appliance 2 according to WOJ31/20237. The appliance 2 is of upright oiboidal configuratfon, and comprises five rectangutar-fironted drawers 4 arranged one above another and housed in a cabinet 6 comprising top 8, bottom 10, sida 12 and raar 14 panels. Any of these panels can be omitted if it is desirad to build the appliance 2 into a gap between other supporting structures; In particuiar, tha sida panels 12 can be omitted if neighbouring cupbowds cwt ba railed upon fbr sum>ort or otherwise to perform the
function of th« side pantls 12. Th« parails 8, 10, 12, 14 may or may not bt structural but If thay ara not, a firama (not shown) providas support for tha various parts of tha applianca. If a frama is providad, ft is structurally imnacassary to have
panels.
The drawers 4 can ba slid horizontally into and out of tha cabinat 6 by means of trades or runners on tha sides of tha drawers 4 that will t>e dasaibed in more detail below. If there is no bade panel 14, it is theoretically possible for a drawer 4 to be removed from tha cabinat 6 In mora than ona diraction, as shown in Figure
2.
Each drawer 4 comprises an insulated open-topped bucket-liice container 16, at least one container 16 (in this case, that of tha cantral drawer 4) being of a different depiti to tha other containers 16 to define a diffierent internal volume. These containers 16 will ba rafirrad to In this spadfic daacription as storage bins or more simply as bins 16. Tha bottom bin 16 leaves only a narrow gap to the bottom panel 10 of tha cabfa^t 6, wharaas tha top bin 16 laavas a substantial space at the top of the applianca 2 under tha top panel 8, allowing room for a compartment 18 that accommodates a rafrigarator angina 20, for axample including condenser and com pressor m eans as is wall known.
The reiativeiy deep bin 16 of cantral drawar 4 is intended to hold bottles and other relatively tail Items storad upright, wharaas tha other, relatively shallow bins 16 are for correqaonduigiy shallower items. Comparad to tha shalves and other compartments dafbiing tha mabi storage voluma of a conventional upright cold-storage applianca, ail of tha bins 16 have a fevourabia aspect ratio in terms of the substantial width of the access opening compared to the depth of the compartment thereby accessed. It Is thwefora very easy to reach every part of tha interior of a
bin 16 when a drawer 4 is opened.
The interior of the cabinet 6 is divided by five insulated lids 22, one for each drawer 4, that are generally planar and horizontally disposed. When a drawer 4 is closed, the open top of its associated bin 1$ is doted by an appropriate one of the lids 22 in a manner to be described. The lids 22 include cooling means 24 being evaporator elements of known type disposed In the lower fece 26 of each lid 22 to cool tiie contents of a bin 16 closed by that lid 22.
Each bin 16 has a generelly fiet front face 28 that is exposed when the drawer 4 is closed. The front fiice 28 could be provided with a decorative panel as is well known. When the drawer 4 is closed, the front fece 28 of the bin 16 is bordered at the top by a control and display panel 30 dedicated to that bin 16, the panel 30 being co>ptanar with the front fece 28. The panel 30 is supported by the front edge 32 of the appropriate lid 22, the panel 30 being recessed into the front edge 32 of the lid 22.
The control and display panel 30 contains a rajmbar of displays* switches and audible alarms, ttuis providing a t»er tnterftrae for each bin 16, For example, the interface wilt most commonly be used for selecting the temperature to which the bin 16 is to be cooled, but also contains twnpTatun displays, on/off and fast-freeze switches, a light indicating when the drawer 4 is opan and an audible alarm to indicate when the ikmtw 4 has t>een open longer than a predetermined time or when the temperabJH'e Inside the bin 16 has reKhed an upper or lower threshold.
A rounded handle 34 extertds across substantially the entire width of the top portion of the front fiice 28 to enable the drawer 4 to be pulled out when access to the interior of the bin 16 is required.
The bottom of th« front (iBOi 28 of MCh bin 16 it bordcrtd by a slot 36 that« as wilt be described, acbnits ambient air into the cabinet 6. To do so, %•&! slot 36 communicates with an air g^ 38 extending beneath the entire bottom fisce 40 of the associated bin 16 to meet a void 42 maintained behind each bin 16, the void 42 being defined by the inner surfaces of the bad( 14 and side 12 penels of the cabinet 6 and the badcs 44 of the bins 16. As can be seen particuiarly from Figure 4, the void 42 extends behkfxi each bin 16 from the base panei 10 of the cabinet 6 to communicate with the refrigerator engine compartment 18 at the top of the cabinet 6.
The air gaps 38 beneath the bins 16 and the void 42 behind the bins 16 also communicate with air gaps 38 to the sides 48 of die bins 16. Optionally, vents 46 are provided in the side panels 12 of the cabinet 6 adjacent to the bins 16 through which ambient air can also be admitted. As best iUustreted in Figures 3 end A, air gaps 38 extend i around ail bar the top side of eadt bin 16, so that ambient air entering the cabinet 6 through die slots 36 can drculato freely eround the sides 48, bottom 40 and rear 44 of each bin 16. It will also be noted that ambient air can circulate freely ov«r the top surface 50 of each lid 22. To allow this airflow over the uppermost (id 22, which does not have a bin 16 above, a slot 36 is provided under the front face 52 of the refrigerator engine compartment 18.
It will be noted that the piston action created by opening a drawer 4 that sucks ambient air into the feitorior of the eppiiance 2 does not pose a problem in this invention. In fact, this action Is advantageous as It promotes circulation of ambient air within the cabinet 6.
Figure 4 shows that the r«frig«r«tor •ngkM oompartm«nt 18 indudts an )mp«l)«r 54 ftxhausting through aparturcs 56 providad in tha (iront fac§ 52 of th« rtfrigerator angina compartmant 16. As bast saan in Figura l, thasa t^>wrtur9s 56 axtand horizontally across tha width of tha front (^ca 52. Tha Impallar 54 communicates with tha void 42 bahind tha bins 16 to draw air from tiia void 42, thus continuously promoting tha induction of ambiant air through tha slots 36 and the optional side vents 46. Upon entering the refrigerator engine compartment 16« this air is drawn through tha haat-axchanga matrix 58 of tha condansar.
Accordingly, ambiant t\r entering die cabinet 6 tivouj^ the front slots 36 and, if provided, dna side vMits 46« leaves ttia cabinet 6 through tha apertures 56 providad in tha front Araa 52 of tha rafrigarator engine compartmant 18, and so ambiant air Is circulated through tha cabinet 6. Mora specifically, ambiant air enters the appliance 2 whwa it immadiataly comas into contact with the outer surfaces 40, 44, 48 of tha bins 16 and warms them to ambiant temperature (or substantially so,, as a surface resistance effiect means that a sub-ambient boundary layer will remain dua to the tMfiparatwa gradient aaoss die thldcness of the bin wall) before being drawn towards tfia void 42 and than upwards tfirough the void 42 by tha ciraiiation of tha air. Tha arrows of Figura 4 demonstrate this circulation of air through die appllanca 2. Accordbngty, tha Interior of tha cabinet 6 Is kept close to ambient temperature, and only die interior of each bin 16 Is cooled.
By exposing the external surfaces 28, 40, 44, 48 of tha bin 16 to warmer air than it contains, there Is no problem with condensation on die external suri^cas 28, 40, 44, 48, and hence no problem with latent heat transfer to die bin 16 or the icing and cross-contwn ination difficulties of condensed water entering tha cabinet 6.
In any ttv^nt, aoss-contamination would b« uniik«ly to ooar b«caus« tach bin 16 is tightly saaiad whan its drawar 4 Is dosad. So, avan if microbas antar tha cabinat 6, they cannot raadily gain accass to othar bins 16. It is also uniikaly that two bins 16 would ba opan togathar at any givan tima. It would ba possible to Include means for enforcing this« for example using a mechanism akin to that used in filing cabinets for anti-tiit purposaSi by preventing mora than one drawer 4 being opened at a time. Such a mechanism will be described later.
When a bin 16 is open, its open top does not suffer much spillage of cold air, and when a bin 16 is cbsed, the horizontal seals 60 apt to be used foi the ynvBntion are inherently better at saailng-in cold air than the vertical seals commonly used In upright refrigerators and freezers. Whilst horizontal seals are known in chest freezers, this invention does not suffer the inconvenience and space problems of chest freezers, instead being akin in those respects to the much more popular upright appliances. The teals 60 can have magnetic qualitias, for example being operable by permarwfit magnets or electromagnets, or may employ hydraulics or pneumatics to expand or contract them.
As there has to be a large temperature gradient between the cooled Inner surfaces 62 of each bin 16 and its outer surl^s 28, 40, 44, 48, the bins 16 are constructed from an efficient insulating material so that the gradient is easily maintained with the outer surfaces 28, 40, 44, 48 remaining dose to the ambient temperature. Materials such as phenolic fbam or polyurethane fbam (optionally skinned with GRP or a polycarbonate in a composite structure) are particutariy preferred for the construction of ^e bins 16.
If segregation of the contents of a particular bin 16 it required, that bin 16 may be fitted with rem ovinia Insert* 64. The Inserts 64 are of varying shape and dimensions and may be used to define many types of compartments. For instance, an insert 64 may be a thfan partition with a length Gorresponding to the length or width of the bin 16 in which it is received. An insert 64 may be a box, with or without a lid, or an insert 64 may include clips for holding bottles in place or trays for holding eggs or the Ittce. An insert 64 could also be a wire basicet or shelf.
As can be seen bi Figure 2, one or more of ttm bins 16 can be removed from the appliance 2 and fitted with an insulated tranH>ort cover 66. The bin 16 may then be taken away from the appliance 2, its Insulated construction ensuring that It Icaeps its contents oool (br a limited period of time. For Instence, ttie bin 16 may be used as a cool-box« possibly In conjunction with ice-padcs to l(eep the interior cool for as long as possAsle. Alternatively, the bin 16 with transport cover 66 may be kept close to the appiianee 2 to provide added temporary cooled storage capacity, furti^er bins 16 i being fitted to tine i^iiance 2 In that event. Further details of transport cover arrarHi«ments will be given later.
It is also possible for a transport covw 66 to include a refrigerator engine powered internally by batteries or a gas supply or externally by mains electricity or a vehicle electricity supply.
Although not shown In the gwieral views of Figures 1 to 4, the Applicant's copending International Patent Application Ho, PCT/6B00/03521 (WO 01/20237) discloses ways in which a bin 16 can be moved with a major horizontal component of movement to gain access to the interior of the bin 16 end, during tiiat access movement, also with a minor vertical component of movement to clear the lid 22. In subsequent developmwtti the Inventor lias devised ottier ways of clearing the
lid 22 end gaining access to the bin 16. The Invwitor hes alto devised otiner technical changes and improvements to WO 01/20237. That new matter will now be described with reftrence to the remabiing Figures, in which the aforesaid reference numerals are used (br lilce parts where possible.
In Figure 5, for example^ the lid 22 is movabia with respect to the structure to separate the lid 22 from the btai 16, thereby allowing the bin 16 to be moved subsequently in a single opwiing direction parallel to the genwal plane of the closed lid 22, I.e. having only a horizontal component of movement In the embodiment shown. In the very simple exemple shown in Figure 5, the lid 22 Is attached to the structure behind the rear edge of the lid 22 by horizontal hinges 68 that enable thu lid 22 to be pivoted VH>w«rdly at its front edge to an extent limited by the bin 16 ^bove. This upward movement of the lid 22 lifts compressible magnetic seals 60 off the top edge 70 of the bin 16 and is sufficient to free the bin 16 to be slid horizontally on simple runners, with no need for the cranks, rollers, ramps and so on that we variously described in WO 01/20237 to effect vertical movement of tt>e bin 16 upon opening and dosing. The raieed lid 22 is held up by a counterbalance weight 72 or a spring compensation device that biases the lid 22 Into the raised position ready for the return of the bin 16 end optionally also into the lowered position atop the bin 16 vthon the bin 16 has been returned and tiie lid 22 has been lowered back onto the top edge 70 of the bin 16.
It will be appreciated that the position of the hinges 68 behind the rear edge of the bin 16 ensures that the rearmost seals 60 are lifted dear of tiie bin 16 or tiiat their pressure upon the top edge 70 of the bin 16 Is at least reduced to the extent necessary to free ti^ bin 16 for horizontel movement.
It is «mphasis«d that tht simpl« arrangcmwit of Figurt S is shown moraiy to illustrats the conoipt of a moving lid 22 and that othar ways of raising a lid 22 can clearly be devised. For axampia, an arrangamant of solenoids, actuators, cams or cranks can be used to raise the entire lid 22 into a raised position that is generally parallel to its lowered position. It is also posstt)le to retract the seals 60 upwardly into the iid 22 or downwardly into the bin 16 so as to free the bin 16 for movement.
Movement of the lid 22 can also be linked to the movement of the associated bin 16 or of a movable s(.4mx>rt for thet bin 16, so that initial opening movement of the bin 16 or its support causes tiia lid 22 to move apart from the bin 16 and« vice-versa« at or toward the end of a dos^ movement of the bin 16 or its support. The sicllled reader will appreciate that the various
In another way of clearing the Ud 22 and gaining access to the bin 16, the Inventor has realised the'potential benefit of separating horizontal and vertical movement of the bin 16. Put more specifically, the Inventor sees benefit in ensuring that when the bin 16 and the lid 22 come Into contact with each other, that contact does not involve e sliding or wiping motion which otherwise could cause the seals 60 to wear and detarkirata over long periods of fraqumt use. Such a sliding or wiping motion across the seals 60 should also ba avokJad whan the bin 16 and the lid 22 are pulled epart The movable-tid variant of Figure 5 hes this benefit, as does the fixed-lid variant of Figures 6(a) and 6(b) which will now be described.
In Figure 6(a), a drawer 4 in accordance with the invention is dosed with its bin 16 sealed to the associated iid 22 by being raised against the lid 22 to oompress a peripheral horizontal seal 60. Figure 6(b) shows the same drawer 4 in two fijrther positions. In solid linear to the left in Figure 6(b), the drawer 4 is partially open in
that tha bin 16 has droppad varticaily away from tha lid 22 to etaar tha taai 60, but the bin 16 has not movad horizontally. In dashad linas, to tha right in Figura 6(b), tha drawer 4 Is fUliy open: tha bin 16 has been movad horizontally on telascoplc runners 74 to afford access to its interior.
The telescopic runners 74 are of two- or thrae^iaoa construction^ as Figure 7 also shows. An outer rail 76 Is attached to the adjacent side panel 78 of the cabinet and so remains stationary in use, whilst one or more inner rails 80 travel forward and bade as the drawer 4 is opened and dosed. As the rails 76, 80 reside within die interior of the cabinet that remeins et or near to the embient temperature, there is no problem of Ice formation that could jam the sliding movement of the rails 76,
80.
Figures 6(a) and 6(b) show a bin transport mechanism associated with the telescopic runners. That mechanism is also shown In Figure 7 in a front part-sectional detail yiew. Spedftealiy* the bfri transport mechanism on each side of the bin 16 comprises a transport plate 82 fixed to the respective telescopic runner. As can be appreciated in Figure 7, the b'ansport plate 82 lies generally vertically beside the bin 16 artd its vertical upper portion 84 is folded eway fi'om the bin 16 to define a recess between itself and the bin 16. That recess accommodates a pair of verticaiiy-oriented movement trantfor wheels 86 that are rotatably attached by horizontal S9>indies 88 to the upper portion 84. Figures 6(a) and 6(b) show that the pair of movement transfkr wheels 86 are disposed one forward, one rearward on eadi tran^>ort plate 82 to each side of the bin 16.
Each movement trensAH- wheel 86 is received by and eonstrate)ed to move in a respective wheel housing 90. Each wheel housing 90 comprises a wheel channel 92 being on inverted U-section that opens downwwdly to receive an upper portion of
eadi movtmant tr«nsi«r wh««l 86 and to constrain that whaai 86 against sidaways movamant Tha bast of tha U-saction baars against and supports a horizontal shoulder surfaca undar an ovarhanging flange 94 that is integral with the wall of the bin 16. As can be seen In Figure 8, the wheel channels are under respective opposed ends of the flange 94 and are linked by a length of flat bar 96 that also lies under the flange 94. The cenb'al portion of the flange 94 between the wheel housings 90 overhangs that bar 96 to define a convenient lifting handle for use when tiie bin 16 is removed from the appliance 2.
Each movement transfir wineei 86 cen move (brwerdiy end rearwardly within its associated wheel housing 90 to a limitsd extant with respect to the bin 16. Accordingly, each wheel housing 90 has formations associated with the wheel channel that constrain and control the movement of the respective movement transftsr wheel with re^>ect to the bin 16. Those formations ere best shown in the detail V lew of Figure 9 of the drew ings.
i
Firstly, forward «id rearward movement of the movement transfer wheel with respect to the bin 16 is limited by forward and rearward buflbrs 98« 100 respectively. Each buf^ 98, 100 defines a respective rest position for the movement transfer wheel 96 so that when the movement transfor wheel 96 Is against the forward buflisr 98, the wheel 96 is at a forward rest position and when the wheel 96 is against the rearward buffor 100, the wheel 96 is at a rearward rest position.
Conveniently, the rearward buffor 100 of a rearward wheel housing 90 has a resilient bade-stop 102 on its r%Brw&r6 surface es shown in Figure 9, that bears against a suitable fixed barrier (not shown) to limit the rearward travel of the bin
16.
/
Secondly, restraining Angers 104( 106 extend fr
Thirdly, a track connects the buffiMr plates 98, 100 to define a nmning surface for the movement transfer wheel 86. The track has flat end portion 442s 110, 112 parallel to the base of the wheel channel 92, namely a forward end portion 110 attached to the base of the wheel channel 92 and a rearward end portion 112 spaced from the base of tha wheel channel 92. Those end portions 110, 112 coincide with the forward vnd rearward rest positions of the movement transfer wheel 86 and are connected by a ramp 114.
A reslti«nt stud 116 at th« junction b«twMn tht rMrward end portion 112 and the ramp 114 aaatas an obstada that must ba ovarcoma if tha movament transfer wheel 86 is to move out of its raarward rest position and ttmn fbrwardly along the ramp 114. This stud 116 tharafora halps to Icaap tha movamant transfer wheel 86 in Its rearward rest position at which tha drawer 4 Is closed and the bin 16 is sealed to the lid 22. Also, the faal of tha drawer movamant as the movement transfer wheel 86 ovar-ridas tha stud 116 givas tha user a positive indication of when tfie drawer 4 and tha bin 16 have raKhad Chair dosed and sealed states.
Elegantly, the bufHisrs 98, 100, the trade 110, 112, 114 and the restraining fingers 104, 106 are folded or febricattd in a singlt component that it simply fixed within the base and side walls of tha wheal channal 92, a$ shown in Figure 9. Tha wheel channel 92 spreads tha loads applied to tha track 110, 112, 114, bufbrs 98, 100 and restraining fingers 104, 106 in use, and applies those loads to the bin 16 via the flange 94.
Figures 10(a) and 10(b) show how tha height of tha bin 16 with respect to the runners 74 responds to tha position of tha movamant transfer wheel 86 within the wheel housing 90. It wiii ba appradatad fi'om Figure 10(a) that when the movement transit wheal 86 Is in tha rearward rest position against the rearward buffier 100, the wiiael channel 92 and hanca tha bin 16 is raised, whereas when thie movement transfer wheel 86 moves along the ramp 114 to the fbrward rest position against tha fbrward buffer 98, tha wheal channal 92 and hence the bin 16 Is lowered.
Returning then to Figures 6(a) and 6(b) to see the bin transport mechanism in operation. Figure 6(a) shows tha bin 16 raised against and sealed to the associated lid 22. In this instance, the bin 16 has been slid to its rearmost extent, as has the
runnor 74 with th« atUKhttd transport piatt 82. Th« runnar 74 has baan slid rsarwardly to that axtant by pushing tha attachad fl'ont pana) 118 of tha drawar 4 rearwardly as fer as it can go. Consaquantiy, tha movamant transfer whaals 86 supportad by tha transport piata 82 ara (bread into tha raarward rast position with respect to their respective wheel housings 90« at which position the wheel channels 92 and hanca tha bin 16 ara raised.
The left-hand portion of Figure 6(b) in solid lines shows fiow opening the drawer 4 by pulling a handle 120 on its front panel 118 initially pulls the runner 74 and the attached transport plate 82 forwards. Tha bin 16 does not move forwwds during that Initial forward movement of tha front panel 118 and runner 74; instead, the movement transfer wheals 86 supportad by tha transport plate 82 move into the forward rest position: this allows tha bin 16 to drop away vertically from the lid 22. It will also be apparent that whan they reach their forward rest positions, each movement transfer wheel 86 bears against the raspactlva forward bufFier 98 and so can transmit continued horizontal drawer-opening force to the bin 16. In this way, when the bin 16 i^as cleared the seal 60, tha drawv 4 can be opened folly into the position shown in dashed lines to the right In Figure 6(b), in which the Interior of the bin 16 is folly accaistt>le. During that movement the upwardly-bent free end portion 108 of the forward retaining finger 104 holds tha movement transfer wheal 86 reslllently In tiie forward rest position so that the bin 16 does not move about unduly with respect to the runners 74. It will be noted that this opening movement of the bin 16 involves no sliding or wiping action across the seal 60.
When the drawer is folly open, tha bin 16 can be removed from the appliance 2. Preforably, the wheel housings 90 >obied by the flat bar 96 remain behind wiien the bin 16 Is removed in this way. Howaver« It would also be possible to lift the bin 16 together with its wheel housings 90 so that tha wheel housings 90 W9 lifted off
tine mov«m«nt tr«nsr wheel 86 rtarwardly fi^om tha fbrward rest position past the upwardly-bent free end portion 108 of the forward rataining finger 104.
Figures 11(a) and ll and 6(b) but show a variant in which closing a drawer 4 and opening It over tha Initial range of movement Is lever-assisted. Such assistanoe may be particularly useful when closing a heavily-laden drawer 4, bearing In mind tha need to lift tha bin 16 slightly over the final portion of tha drawer-dosing movement Elegantly, tha front panel 118 of the drawer 4 serves M tha lavar by being pivotally attached to tha runner 74 and/or the transport plate 82 such that tha pivot axis 122 lies horizontally just below the mid point of the fi'ont paruii 118. Consequently, when the handle 120 at the top of the firont panel 118 is pulled upon opening the drawer 4, the ft'ont panel 118 pivots about tivi pivot axis 122 (hn a dockwte direction as drawn) und this causes tine lower edge 124 of tha trw\t panel 118 to press against tha lower fi'ont part of tine bin 16. That pressure assists tha ralativa movement between the runner 74 and tine bin 16 that is necessary (br tha bin 16 to drop away firom the lid 22.
More specifically, tha lower edge 124 of tha firont panel 118 is associated witin a bar 126 that engages a downwardfy-opanlng hook 128 fixed to the fi'ont face of the bin 16. As the hook 128 opens downwardly, it alk>ws the bin 16 to move up and down whan making or breaking tha seal; it also allows tha bin 16 to be removed from the appliance 2 by lifting it ofP the movement transfM- wheels 86 as aforesaid. Yet, when tine drawer 4 is being closed and closing pressure is therefore applied to the handle 120 at tha tc^) edge of tha firont panel 118 (which causes the fi'ont panel
118 to pivot in «n anti-dockwiM dirtctlon 4M drawn), th« bar 126 appliat forct to tha bin 16 via tha hook 126 to hold tha bin 16 whila pushing tha runnar 74 raarwardiy with raspad: to tha bin 16. It Is this ralativa movamant that iifts tha bin 16 against tha lid 22 and banafits most (irom tha machanlcal advantaga aflbrdad by tha iavar.
A further feature evident i^onn Figures 6(a) and 6(b) and Figures 11(a) and 11(b) Is a rack-and-pinion machanlsm 130 whose primary purpose is to resist latarai sway of a drawer 4 supported by tha runrmrs 74 as it op«is and doses. The radc-and-pinion medtanism 130 is also shown in plan view In Fi(^ra 12. In that madianism, an arm 132 dapwids raarwardiy and downwardly from tha transport plate 82 on eadi skle of a bin 16 (the outline of whidi la shown In dashed lines in Figure 12) and terminates in a bearing 134 defining a horizontal axis of rotation below and behind the rewwvd feca of tha bin 16. As can ba appredated from Figure 12, the bearings 134 of tha raspactiva arms 132 align and co-operate to support a horizontal spindle 136 that spans the gap between tha arms 132.
The spindle 136, k\ turn, supports a pab* of ptailons 138 fixed to die spindle 136 such that one pinion 138 is disposed adjacent each and of the spindle 136, just Inboard of each bearing 134 that supports tha spindle 136. The pair of pinions 138 are engaged with a correspondingly-spaced pair of parallel racks 140 that are on top of tha lid 22 or otiiar horizontal surfeca (notably tha top surface of the base panel) babw the drawer 4 In quastton, and extend orthogonally to the spindle 136 from the front to tha back of that Ikl 22 or surface, at least as fisr as tha opening m ovem ent of the drawer 4 dictates.
In use, when tha drawer 4 Is being opened or dosed, the pinions 138 are constrained by tha bitarcortnect^ splndia 136 to turn with one another. Any
lateral $way axpariancad by th« drawtr 4 tends to mova dia spfaidia 136 out of its ordiogonal raiationship widi ttM racks 140, and so trias to craats a spaad differantlal batwaan tha pinions 138 as thay mova along tha racks 140. This conflict tharafbra causas ona pinkm 138 to apply torqua to tha othar pinton 138 via tha splndia 136; that torqua tands to corract or at laast raslst tha indplant sway. Tha spindia 136 may tiwist slightly as a rasuit of tha appiiad torqua but this haips to prevant aither of tha pbitons 1^ skiing out of angagamant with thair racks 140 and hanca potantiaily outof aiignmant with aach othar.
Figura 12 also shows a limit switch 142 naar tha raar of ona of tha racks 140, and a locking solanoid 144 also associatad with tfia rack 140 but positionad slightly forward of tha limit switch 142. Tha purposa of tha locking solanoid 144 is to pravaht tha associatad drawar 4 baing opanad, by for axampla blocking forward movfunwit of tha arm 132 that di^iands firom tha transport piata 82. On the other hand, tha limit S|wibdh 142 intaracts with tha arm 132 of tha transport piata 82, or with tha spindia 136 supported by that arm 132. to sense opening and closing of the drawer 4.
By virtue of its rearmost position as shown in Figure 12, the limit switch 142 is triggered when the transport plate 82 and Ito associatad arm 132 Is moved into or from Its rearmost position consistent with sealing tha bin 16 against tha lid 22. If the bin 16 is not sealed in that way, this will be indicated by tha transport plate 82 and its associatad arm 132 being forward of its rawinost position and will be sensed by the limit switch 142. In that case, tha limit switch 142 can be used to trigger an alarm (prafor^ly after a timeout pertod has elapsed) and/or to cause the correspondNig solenoids 144 of other drawers to k>ck thmk drawers 4 closed until the open or unseated drawar 4 has been returned to its closed position and its bin 16 has been sealed agairwt the associated lid 22. This allows only one drawer 4
to b« op«n at a timt and so providts an anti-tiit fadiity akin to a filing cabinet tliat, in the context of coid s^orage^ also has the unique benefit of limiting aoss-contam ination between items stored in different drawers 4.
The locking soienokl 144 can also b« controlled mdepfHridentfy of a Ihnlt switch, for example by connecting ail of the solenokte 144 of a multi-drawer appliance 2 to enable central k>cklng of aif of its drawers 4, pref^ably by a common key-operated switch (not shown). Preferably, to the benefit of enwgy consumption, the solenoid 144 unlocks Its drawer 4 when energlstd and so locks that drawer 4 when de-energised. More preferably in such an arrangement, ell of the drawers 4 remain iodced with theb* soienokis 144 de-energised until a user-selected one of the drawers 4 is unk>cked by, for example, pressing an appropriate button to energise its sokunoki 144 or touching a corresponding touch-switch associated with the handle of that drawer 4. Once energised, a solenoM 144 may remain energised constantly until another drawer 4 is selected to be operuKi; prefiirabiy, however, that solenoid 144 is de-energised after a timeout period to tock its drawer 4 until a user selects that drawer 4 to be unkKked once more.
Whilst electric locking solenoids 144 have been mentioned, it will be clear to the skilled reader that other actuators or locking mechanisms operating on hydraulic, pneumatic or mechantoal principles can be used instead.
Returning to the appliance 2 itself, Figures 13(a) and 13(b) show preferred details of the lids 22 to whwh the bins 16 seal when fitted in the appliance 2. Figure 13(a) shows that the lid 22 is oblong In plan view. The oblong dashed outlines of features below the Iki 22 are also apparwit Starting inwardly and movbig outwardly, those features are an evaporator 194 disposed centrally on the underside of the lid 22, a drain pan 196 disposed beneath the evaporator 194 to catch water that drips from
tha evaporator 194, and a racats 198 in tha undarsida of tha lid 22 that accommodates both tha drain pan 196 and tha evaporator 194.
As best appreciated from Figure 13(b), which is a aoss-section on line A-A of Figure 13(a), tha recess 198 Is bounded by a peripheral skirt 200 depending from the lid 22. A pair of oblong comprassibia seals 60 lie one within tha other on tha lower end face 202 of the skirt 200. Those seals 60 are cont^ous save fbr an opening that accommodates an obk)ng-sectk>n drainage duct 204 leading rearwardly from the drain pan 196. The drain pan 196 has an indlned base 206 to lead water toward that drakiage duct 204, from whkh thm water is channelled away from the lid 22 as Figure 14 will explain. A temperature sensor (not shown) can penetrates tha dcirt 200 9bov tha seals 60 to measure the temperature within the cavity sealed by^the bin 16 and the Ikl 22.
Figure 14 shows how it is preferred that separate dr«in duets 208 run from each drain pan 196 of a multl-bin appliance 2. This minimises tha risk of cross-contam Ination. Each duct 208 irtdudas a U-band 210 defining a sealing water trap and drains separately to a common tray 212. That tray 212 may be located above a compressor 214 of the appliance 2 as shown so that, over time, heet emanating from the compressor 214 evaporates the water from the tray 212 at least as quickly as that water accumulates In the tray 212. In addition or In the alternative, the condenser fan of the appliance 2 (not shown) can blow aaoss the surface of water in the tray 212 so as to promote its evaporation.
Figures 15(a) and 15(b) show a (Urther lid design suitable (br use in a fen coil cooling system in which air is suppikKi to tha bin 16 and extracted from the bin 16 via a remote fan coil unit Such a system is also known as a frjrced air system, and the lid 22 In Figures 15(a) and 15(b) is hollow and partittoned to govern the flow of
air on whidi such systttms d«p«nd. Thus, cold air coolad by a haat ax changer (not shown) is pipad undar prsssura l^om a fan (not shown) into a supply air plenum 216 disposed peripherally within the lid 22, from which that air enters the bin through supply air diflusion slots 218 around a base panel 220 defining the underside of the lid 22. Wwmer 9\r is extracted from the bin 16 through a centrally'disposed return air plenum 222 that oommunicatet with the bin 16 through a central hole 224 in the base panel 220 and with the fan through a pipe 226 extending through the surrotnidlng supply air planum 216. The warmer air is drawn into the return air plenum 222 under low pressure created by the fan, and Is than sent to the heat exchar>ger to be cooled und radrcuiated via the supply air plenum 216.
Apart from the vertical array of drawers 4 common to the embodiments described above, a side-by-tide arrangement of (ft-awers 4 is also contemplated as shown in Figures 16(a), 16(b) and 16(c). The front view of Figure 16(a) shows a four-drawer bench-type eppiiance 268 (to which Figures 23 tnd 24 also r«fer) in which the drawers 4 are in two adjacent columns of two drwrnmrt 4 eadi. Thus, the appliance 268 is low enough to have a worktop 270 over the drawers 4, straddling the two columns. This embodiment of the invention is therefore suitable for use as a refrigerated food preparation and/or servery unit.
The dep^ of the (fa-awers 4 is maximised within the limited available height by mounting the refrigerator migirm 272 and control panel 274 in a side-slung position to one side of the alliance 268 as shown. Also, the side view of Figure 16(b) and the enlarged detail aoss-sectional view of Figure 16(c), taken on line X-X of Figure 16(a), shows that the front edge of the worktop 270 hes a raised lip 276 that helps to prevent spillages on the worktop 270 dripping down onto or into the drawers 4 below.
Figures 16(a) and 16(b) also show how an applianca 268 of tha invantion can be mounted on castors 278; those castors 27B can be height-ad^istabie to level the appliance 268 on a non-level floor 280.
Refiarring now to Figures 17 to 24, these show two fUrther bin transport mechanisms being altematives to those shown in Figures 6 to 11 above. They address potential disadvantages of the previously-described bin transport mechanisms. One disadvantage Is that when the drawer of the Figures 6 to 11 embodiments is extended and is pushed sharply when being closed, the wheels 86 will tend to travel up the ramps 114 before die rearward drawer movement Is complete, so reisirn) the bin 16 and possibly risking a dash when the rear top edge of the bin 16 encounters the front lower edge of the lid 22. A steady motion Is therefore essential to return the drawer to its fUily dosed position before fUrther pressure pushes the wheels 86 up the ramps 114 to teaf the bin 16 to the lid 22. Another disadvantage is that the wheel spindles 88 take the weight of the bin 16 and the seal compresskMi forces, whkh increases die risk of failure.
Looking firstly at Fi{Mres 17(a> to 17(c), the bin transport mechanism on each side of the bin 16 comprises a transport plate 408 fixed to a telescopic runner 410, the transport plate 408 lying generally vertically beskje the bin 16. (Jnlike the embodiments of Figures 6 to 11, the transport plate 408 extends downwardly below the bin 16 to terminate in an inwardly-directed flange 412 disposed orthogonally with respe^ to the transport plate 408. The fisoige 412 lies between the underside of the bin 16 and the lid 22 of the bin 16 below, or an equivalent structure, and is connected to the lid 22 of the bin 16 below, or the equivalent structure, via a telescopic runner 414 tfiat lies horizontally. The purpose of that runner 414 is to resist lateral sway of a drawer 4 supported by a pair of runners
410 as it op«ns and closas. Such m\ anti-sway runnw 414 can be to on« sida of the bin 16, to both sides of tha bin 16 or can ba disposed osntrally within raspact to tha bin 16.
Vertically-oriented movement transfer whaels 416 are disposed in pairs, each pair comprising ona wheal 416 disposed above the other for rolling contact between them while transmitting bin weight and seal compression loads from one wheel 416 to the other. The pan's of movement transfer wheels 416 are disposed one pair forward, one pair rearward on each transport plate 408 to each side of the bin
16.
The wheels 416 of each pair are rotatably attached by respective horizontal spindles 418 to a wheel plate 420 that floats vertically within a pocket defined by a wheel bracket 422 attached to the transport plate 408. The wheel plate 420 is free to move vertkuilly within the pocket but is restrained against felling out of the pocket by a retabibig flange 424 on Its upper end. The flange 424 defines a shoulder that bears against the wheel bracket 422 at the top edge of the pocket when the wheel plate 420 Is at its fowest point within the pocket.
A transport plate 408 fitted with wheel t>radcets 422 each carrying a respective wheel plate 420 and a pair of wheels 416 Is shown In Figure 19.
The upper wheel 416 of each pair is received by and constrained to move in a re^ective wheel housing. Each wheel housing comprises a wheel channel defined between a cover plate 426 that partially shrouds the wheel bracket 422, and an Inverted L-section 428 that beers against and st9^>orts a horizontal shoulder surfece under an overhanging flange 430 projecting from the wall of the bin 16. The flange 430 extends around the front, skies arKi rear of the bin 16 and the L-
section 428 forms part of a bin support firama 432 illustrated In Figure 20. The flange 430 that extends around the bin 16 sits on the frame 432 in such manner that the bin 16 can be lifted out of the frame 432.
Each upper wheel 416 can move fbrwardly and rearwardly within its associated wheel housing to a limited extent with respect to the bin 16^ and each wheel housing has formations associated with the wheel channel that constrain and control the movement of the upper wheel 416 with respect to the bin 16. Those formations are best shown In Isolation In the detail view of Figure 21 of the drawings.
Forward and rearward buffers 434, 436 limit forward and rearward movement of the upper wheel 416 with respect to the bin 16, and a tracl
The wheel housings are part of a bin support firame 432 shown in Figure 20 that defines the wheel channel and supports the housing components 440 defining the buffers 434, 436 and tracks 438. The front housing component 440 Is lower than the rear housing component 440 by virtue of a packing strip 450 between the L-sectlon 428 and the front housing component 440.
Figure 20 also shows that tht rtar of th« bin support frame 432 comprises a rear bin support channel 452 that carries a support bracket 454. An engaging lever 456 is pivotally attached by a spindle 458 to the support bracket 454 for limited movement about o horizontal pivot axis. The lever 456 comprises an arm 460 extending forwardly from the spindle 458 and a crank 462 depending rearwardly and downwardly from the spindle 458| the crank 462 terminating in a leg 464. The weight and length of the arm 460 creates a torque acting about the spindle 458 that exceeds the opposing torque created by the weight and length of the crank 462 and leg 464. Thus, gravity biases the lever 456 which tends to pivot clockwise as shown, with the arm 460 moving downwardly. However, the lever 460 cannot reach an equilibrium position of balance about tiie pivot: Instead, the movement of the arm 460 is restrained by encountering a rearward extension 466 of the transport plate 408 as the bin 16 moves forwardly with respect to the arm 460, as will be explained below with reference to Figures 22(a) to 22(d).
As will also be explained with reference to those Figures, a striker plate 468 is fixed to the structure of the appliance at the rear of the drawer compartment and the leg 464 of ti^e crank 462 is positioned to bear against the striker plate 468 when the drawer is closed. This lifts the arm 460 of the lever out of engagement with the rearward extension 466 of the transport plate 408.
A resilient back-stop 470 fixed to tiie structure of the appliance bears against the support bracket 454 when the drawer Is closed so as to limit the rearward travel of the bin 16.
As best shown in Figure 17(c) and Figures 22(a) to 22(d), a shelf 472 faces Inwardly from the structure of the appliance to one side of the bin 16, Just above the runner 410. Platforms 474 are disposed one forwardly and one rearwardly on
X
the upper face of the shelf 472 to correspond to the positions of the wheel pairs 416. A packing strip 450 between the rearward platform 474 and the shelf 472 corresponds to the pacldng strip 450 between the front housing component 440 and the L-section 428.
The purpose of the two packing strips 450 is to ensure that the lower wheel 416 of the rearward pair clears the forward platform 474 as the bin 16 Is opened on its runners 410.
The forward end of each platform 474 is tapered to define a ramp up which the lower wheel 416 of the respective pair can run to mount the platform 474. The weight of the bin 16 is then borne by the shelf 472 via the wheels 416 (whose spindles 458 bear no load), the track 438 on which the upper wheel 416 runs, the L-section 428 forming part of the bin support frame 432, and the flange 430 that extends around the bin 16 and sits on tiie frame 432.
Figures 22(a). 22(b), 22(c) and 22(d) show the bin transport mechanism in operation, with reference to a rearward pair of wheels 416 with its associated wheel housing, wheel brad
Figure 22(a) shows the bin 16 raised against and sealed to the associated lid 22. In this instance, the bin 16 has been slid to Its rearmost extent defined by abutment of the support bracket 454 with the resilient bad
420 is forced into a rearward position with raspact to its wliaal housing, at which position the upper wheal 416 of the pair is on tha rearward ramp portion 446 near the ridge 448. Simultaneously, the lower wheal 416 of tha pair is supported by the platform 474 to transfer loads between tha bin 16 and the shelf 472 that holds the platform 474. Thus, tha wheal channels and hence the bin 16 are raised, compressing the seal (not shown) between the bin 16 and the lid 22. It will also be noted that the leg 464 of the arank 462 bears against the striker plate 468, which iii^s the arm 460 of the lever 456.
Figure 22(b) shows the next step, in which the transport plate 408 has been pulled forward such that the pair of wheels 416 adopts a forward position with respect to its wheel housing. At this position, the upper wheel 416 of the pair has surmounted the ridge 448, rolled along the forward ramp portion 444 and onto the flat end portion 442 of the track 438 adjacent the forward bufter 434. The ridge 448 therefore acts ins a detent against opening that holds the drawer closed, but can be overcome with minimal effort upon opening.
At the stage shown in Figure 22(b), the lower wheel 416 of the pair is still supported by the platform 474 to bear the weight of tiie bin 16, but the position of the upper wheel 416 In the fiat end portion 442 of the track 438 allows the bin 16 to drop away from tha lid 22, breaking the seal before the bin 16 moves in an opening direction. Otherwise, the bin 16 remains in mudi the same position as shown in Figure 22(a). In particular, the leg 464 of the crank 462 still bears against the striker plate 468, whidi holds up the arm 460 of tiie lever 456.
When opening movement of the bin 16 begins, as shown in Figure 22(c), the pivot 458 of the lever 456 moves away firom the striker plate 468, which allows the arm 460 of the lever 456 to drop into engagement with the rearward extension 466 of
the transport plate 408. That engagement Is maintained, locking the transport mechanism, until the drawer again nears its closed position upon closing. At that stage, the leg 464 of the crank 462 bears against the striker plate 468 and lifts the arm 460 out of engagement with the rearward extension 466 of the transport plate 408 to free the transport mechanism once again.
As the drawer opens further, the weight of the bin 16 must at some stage transfer from the shelf 472 within the drawer compartment to the runners 410 extending outside the drawer compartment. This Is achieved when the lower wheel 416 clears the ramped forward end of the platform 474 as shown in Figure 22(d), which allows the bin 16 to drop Into contact with the inwardly-facing flange 412 at the bottom of the b'ansport plate 408. As the transport plate 408 is supported by the runners 410, the load transfers to the runners 410. Meanwhile, the wheel plate 420 drops to the extent permitted by the retaining flange 424, clearing the upper wheel 416 from the track 438. The wheels 416 then no longer bear the weight of the bin 16.
It will be evident that when the drawer is closed again, the lower wheel 416 encounters the ramped fbrward end of the platform 474, lifts the wheel plate 420 and hence lifts the upper wheel 416 Into contact with the track 438. This transfers the load of the bin 16 back to the shelf 472 within the drawer compartment, via the track 438, tiie wheels 416 and the platform 474.
The variant in Figures 23(a) and 23(b) and Figures 24(a) to 24(c) replaces the wheels 416 and their associated structures with pairs of opposed blocks 476 that slide relative to one another and are shaped to impart the desired motion and sequence of motions to the bin 16. Otherwise, like numerals are used for like ports.
Each block 476 is of plastics materia! coated or Impregnated with, for example. PTFE to minimise friction. Broadly, each block 476 defines a contact surface comprising two horizontal portions linked by a slope, the horizontal portions thus being at different levels. Specifically, all of tine blocks have contact surfaces that rise toward the front of the appliance. Thus, a rearward horizontal portion 478 is lower than a forward horizontal portion 480 of each contact surface and the slope 482 between those portions 478, 480 rises moving fbrwardly.
The lower block 476 of eadi pair is attached to the transport plate 408 and its contact surface faces generally upwardly, whereas the upper block 476 of each pair is attached to an L-section 428 that supports the flange 430 of a bin 16 and its contact surface faces generally downwardly. The thickest part of the lower block 476 is at its forward end defined by its forward horizontal portion 480 whereas the thickest part of the upper block 476 Is at Its rearward end defined by Its rearward horizontal portibn 478. Thus, the contact surfaces of the upper and lower blocks 476 of a pair are opposed and complementary in shape. Indeed, the respective contact surfaces can mate with each other when the blocks 476 of a pair are aligned.
A iug 484 depends from the forward end of the upper block 476 to prevent forward movement of the lower blodc 476 past ti^e upper blod( 476 when the drawer is
opened.
When the drawer is closed and the bin 16 Is sealed to the lid 22 as shown In Figure 24(a), the transport plate 408 and hence the lower blocks 476 are fully rearward. This brings the forward horizontal portion 480 of the lower block contact surface into register with the rearward horizontal portion 478 of the upper block contact
surface. Put anothar wayi the thickest parts of tha blocks 476 coincide and hence the aggregate thickness of the pair of blocks 476 Is at a maximum. This forces the bin 16 upwards into sealing contact with ttie lid 22« although the seal is not shown.
Referring now to Figure 24(b), when the runner 410 and transport plate 408 moves to the right as drawn as part of the initial opening movement of the drawer, the lower block 476 moves fbrwardly with respect to the upper block 476. This movement continues until the lower btod( 476 encounters the lug 484 that depends from the forward end of tine upper block 476 and so no further relative movement of the blocks 476 can occur during drawer opening. At that stage, the blocks 476 are aligned and their opposed, complementary contact surfaces mate with each other. The effect of this Is that the thickest part of each block 476 coincides with the thinnest part of the other block 476, and so the aggregate thickness of the pair of blocks 476 Is at a minimum. This allows the bin 16 to fall away from the lid 22 and hence breaks the seal.
As the lug 484 that depends from the forward end of the upper block 476 then prevents ^rther relative movement of the blocks 476 during drawer opening, horizontal force applied to the lower block 476 via the transport plate 408 is transmitted to the upper block 476 and hence pulls the bin 16 horizontally within Its support frame 432. This Is shown In Figure 24(c), which like Figure 22(c) above also shows how the arm 460 of the lever 456 engages a rearward extension 466 of the transport plate 408 as the drawer is opened and the pivot 458 of the lever 456 moves away from the striker plate 468 within the drawer compartment.
Figures 24(a), 24(b) and 24(c) are akin to Figures 22(a), 22(b) and 22(c) in their progression but as the weight of the bin 16 is at all times carried by the runners 410 via the transport plate 408 and the blocks 476, there Is no need for the bin 16
to be lowered onto the flange 412 of the transport plate 408 In the manner of Figure 22(d) in which the wheels 416 are uncoupled (irom the bin 16.
Another deficiency with drawers is the effect on the drawer contents during rapid changes tn velocity (i.e. sudden acceleration and deceleration), as tends to happen on opening and closing. When the drawer is moved suddenly or Is stopped quickly, the contents of the drawer can be tinrown around causing damage to delicate Items and/or spillage of liquids. Depending upon what is in the drawer, this could affect Items such as cakes and pastries, liquids In jars and bottles, rare samples and artefacts. The damage caused could range from annoying wastage of inexpensive items and a mess to clean up, through to loss or irreparable damage to irreplaceable samples or artefects. It is therefore advantageous for a drawer transport system to control acceleration and deceleration or braking during opening and closing to protect the drawer contents.
Moving on therefore to Figure 25 and its associated cross-section, Figure 26, these
t
show a further embodiment in which like numerals are used for like parts. In this embodiment, a drawer lid 22 is fixed to a structure and a removable drawer storage bin 16 Is movable with respect to the lid 22 and the structure. The bin 16 is supported from a top flange 500 formed in the bin 16. The flange 500 in turn sits on a drawer support profile 502, which is fitted with forward and rearward wheel ramps 504 as detailed in Figure 27. The wheel ramps 504 sit upon freely-rotating load-bearing wheels 506, attached to the top section 508 of a telescopic drawer runner 510. Supporting the bin 16 in this way via wheel ramps 504 on the drawer profile 502 and wheels 506 fitted to the runner 510 allows the bin 16 to move independently of the runner 510.
Figure 27 shows that as in the embodiment of Figures 17 to 24, the wheel ramps
504 are defined by a whMl housing 512. The who«l housing 512 comprises forward and rearward buffers 514, 516 that limit forward and rearward movement of a wheel 506 with respect to the bin 16| and a trade 518 which connects the buffers 514« 516 to define a running surface for the wheel 506. The buffers 514, 516 and the track 518 are again folded or fabricated In a single component.
The track 518 has an upwardly- and forwardiy-lncllned forward end portion 520 at its forward end adjacent the forward buffer 514. The rearward end of the forward end portion 520 defines a ridge 522 In the track 518. Moving rearwardly from there, the track 518 defines a rest position between opposed upwardly-inclined ramp portions 524, 526 and after a farther ridge 528, ends In an upwardly- and rearwardly-inclined rear end portion 530 adjacent the rearward buffer 516.
The rest po&ition at the apex 532 of the intersecting ramp portions 524, 526 is above the level of the ridges 522, 528; were the housing 512 Inverted, this apex 532 would be a( trough between th% ridges 522, 528.
Figure 25 shows the drawer closed with tiie bin 16 raised and the horizontal seal (not shown) compressed, with each wheel 506 at the rearward end of Its housing 512 adjacent the rearward buffer 516. It will be noted that the radius of the wheel 506 is slightly less than the distance from the rearward buffer 516 to the rearward ridge 528. Thus, the centre of tiie wheel 506 is marginally rearward of the rearward ridge 528, so that the wheel 506 Is biased rearwardly up the rear end portion 530 of the track 518 under the weight of the bin 16. This provides an over-centre locking effect, which can be readily overcome.
As detailed in Figures 28 and 29, each load-bearing wheel 506 (shown here inverted) is associated with a pair of auxiliary rollers 534 angularly spaced about
the spindle 536 of tha whefti 506, opposed to the point of rolling contact between the wheel 506 and the track 518 of the wheel housing 512. The auxiliary rollers 534 are In rolling contact with the wheel 506 and help to bear the load of the bin 16, taking loads transmitted across the wheel 506.
It can be seen in Figure 25 that the drawer runners 510 extend rearward of the bin 16 to allow additional horizontal movement of ^e runners 510 beyond that of the bin 16. This additional horizontal movement of the runners 510 with respect to the bin 16 will take place on initial opening and on final closing of the drawer. On opening the drawer, this extra runner movement moves the wheels 506 fbrwardly along their tracks 518 to drop the bin 16 vertically and so to de-compress the seal on initial opening. In doing so» a wheel 506 takes a mid position at or near the apex 532 of its track 518 as the bin 16 is withdrawn with the runner 510. On returning the bin 16 and runner 510 to the closed position, the bin 16 hits a stop at its completely closed position, with each wheel 506 still at the apex 532 of its track 518. The final closing motion pushes the wheels 506 rearwardly along the tracks 518 to the over-centre locking point shown In Figure 25, which raises the bin 16 and compresses the seat against the lid 22.
The full drawer transport sequence is illustrated in Figures 30(a) to 30(f). Figure 30(a) corresponds to Figure 25, showing the drawer closed and the bin 16 raised to compress the horizontal seal (not shown), with the wheels 506 at the rearward end of their wheel housings 512. Figure 30(b) shows the drawer runner 510 forward of the closed position where the wheels 506 have moved along the respective tracks 518 to a mid-position at the apex 532 and released the seal, and where the bin 16 has dropped down but has not moved forward. Figure 30(c) shows the runner 510 and bin 16 in a semi-open position, whereas Figure 30(d) shows the runner 510 and bin 16 in a fully-open position. Figure 30(e) shows the runner 510 and bin 16 in
a semi-closed position, while Figure 30(f) shows the bin 16 in its closed but dropped position with the runner 510 slightly forward of the closed position, in readiness for the final closing action of pushing the wheels 506 rearwardly along the tracks 518 to raise the bin 16 and compress the seal, whereupon the sequence returns to its starting point at Figure 30(a).
A variation on the above arrangement would be to make the wheel tracks 518 out of a low-friction material such as PTFE or a PTFE-coated material, with a suitable PTFE or PTFE-coated profile fixed to the runner 510 Instead of a wheel 506.
The embodiment of Figures 25 to 30 also Includes means for partially Isolating the movement of the runner 510 from that of the bin 16, thus reducing acceleration and braking forces Imparted to the bin 16. The system of wheel housings 512 fixed in relation to the bin, and the wheels 506 fixed to the runners but floating within the wheoi housings 512 permits limited Independent movement between the bin 16 and the runner 510. Thus, sudden acceleration and deceleration to the runner 510 can be partially absorbed by limited independent movement of the bin 16, which reduces the rate of change In bin velocity and hence the Inertial effects experienced by items stored In the bin 16.
It will be noted that when the accelerations of the bin 16 and runner 510 are near equilibrium, the wheel 506 will sit around the central rest point at the apex 532 of the wheel track 518. When the runner acceleration changes rapidly, such as hitting an end stop or when the drawer Is jerked open, the direction and motion of the bin 16 will continue as the wheel moves along the track 518 from the apex 532 toward one of the ridges 522, 528. This vertical movement up the upwardly-inclined ramp portions 524, 526 against the weight of the loaded bin 16 absorbs some of the kinetic energy in the bin 16, and thus slows It to a gentler stop.
A further refinement of the tmbodiment of Figures 25 to 30 is a control damper. Referring especially now to Figure 31, this shows a simple piston-operated air damper 538 to restrict the acceleration and braking of the drawer runner. The damper has a cylinder 540 whose rear end terminates in a pin 542 that is fixed to the structure of the appliance at Its rear. A rod 544 slides within the cylinder 540 and has a piston 546 at one end, slldeably sealed within the cylinder 540, and another pin 542 at the other end for attadiment to the bottom section 548 of the runner 510 as shown In Figures 30(a) to 30(f). As the rod 544 and piston 546 are pulled from the cylinder 540, air is drawn though a small orifice 550 in the blind end of the cylinder 540. The orifice 550 Is sized such that below a limiting piston speed, the passage of air through the orifice 550 causes little resistance (i.e. differential pressure over the orifice 550) and the rod 544 can be moved easily. As the speed of the piston 546 increases, then so does the resistance across the orifice 550 mal
The purpose of the damper 538 is to control the sjaeed of the runner 510 from midpoint to flilly open, also from mid-point to fully closed, preventing a Jarring stop in both directions. Alternatively, dampers 538 could be fitted to both sections of the runner 510 to provide speed control over the entire travel of the runner 510.
Referring baci
548 Of the runner 510 restrained by the damper 538. Figure 30(c) shows the bin 16 at about mid-point in opening with the top section 508 of the runner 510 fully extended and the bottom section 548 of the runner 510 still restrained by the damper 538. Figure 30(d) shows the bin 16 (Ully open with both runner sections 508, 548 and the damper 538 dilly extended. Indicating that the damper 538 had control over the last part of the bin opening movement. Figure 30(e) shows the bin 16 at about mid-point in closing with the top section 508 of the runner 510 fully retracted and the bottom section 548 of the runner 510 fully extended and restrained by the damper 538. Figure 30(0 shows the bin 16 and top section 508 of the runner 510 flilly retracted with the bottom section 548 of the runner 510 and the damper 538 significantly retracted. Indicating that the damper 538 had control over the last part of the bin closing movement.
Figures 32(a) to 32(0 show a refinement of the damper concept, in which the piston 552 Is itself a cylinder sliding concentrlceJIy witiiin the outer cylinder 554. The outer cylinder 554 has no orifices and is sealed to the piston 552 by a sealing gland 556 between the piston 552 and the outer cylinder 554 near the otherwise open end of the outer cylinder 554. The piston 552, on the other hand, has a series of orifices 558 spaced along the length of the piston 552.
It will be self-evident tinat when the piston 552 Is forced Into the outer cylinder 554, the piston 552 wilt compran air trapped within the outer cylinder 554. That compressed air can only escape firom the outer cylinder 554 by passing through the cylindrical piston 552 via one or more orifices 558 lying within the outer cylinder 554 and one or more orifices 558 lying outside the outer cylinder 554. However, when the piston 552 is fully retracted within the outer cylinder 554 as shown in Figure 32(a), all of the orifices 558 are within the outer cylinder 554: none of the orifices 558 can communicate within the outside, so there is no net
flow or air out of the outer cylinder 554. This traps compressed air, which provides a cushioning effect as tiie damper approaches Its fully retracted state.
Conversely, when the damper is in a semi-extended or semi-retracted state as shown for example In Figures 32(c) or 32(d), more than one orifice 558 is within the outer cylinder 554 and more than one orifice 558 Is outside: this presents minimum resistance to air flow and so minimises the damping effect when the damper is in mid-stroke. However, when the damper nears the fully-extended state as In Figure 32(0i only one orifice 558 is within the outer cylinder 554 and whilst several orifices 558 are outside, ^e airflow through them is limited by the airflow through the single orifice 558 within: tills presents greater resistance to air flow and so maximises the damping effect when the damper nears the end of its strol
Further enhancements to the drawer transport system will now be described. They include methods to limit the Independent movement between the runner and bin, and alternative end-of-travel restraints.
It will be apparent that the system employing wheel ramps and wheels as Illustrated in Figures 25 to 30 wilt raise tiie bin 16 when the runners 510 are rapidly accelerated in mid-travel. Where this is not desirable, a movement limiting system may be employed as shown In Figures 33(a) to 33(e). Figure 33(a) shows a drawer transport system with the bin 16 closed with its seal 600 compressed against a lid 22, supported by a wheel 506 parked on a flat portion 602 of the rear part of a wheel track 518. To drop the bin 16 to open it and break the seal, the wheel 506
moves forwardly along th« wh«tl track 518 out of tha parkad position, In this state, the three dashed line circles shown on the wheel track 518 indicate the rearward and forward travel limits and tha normal centra position of the wheel 506. Rearward bin movement in relation to the runner 510 Is limited by the assembly Including tha wheel 506 encountering tha forward buffer 514 at the front of the wheel track 518.
A pivoting engaging lever 604 is attached by a spindle 606 to a support plate 608 that travels with the wheel track 518 and so moves In relation to the runner 510. The lever 604 pivots to limit the forward movement of the bin 16 in relation to the runner 510 during normal bin movement. Specifically, when the drawer Is opened, the front end of the lever 604 drops down under gravity and engages with a stop plate 610 attached to the runner 510. This engagement between lever and stop plate limits the forward motion of the bin 16 In relation to the runner 510, and so prevents the wheel 506 travailing the full length of the track 518 into the parked position 602, in which tha bin 16 Is raised.
To remove the forward limit by disengaging the lever 604 from the stop plate 610, the rear of the engaging lever 604 hits a striker plate 612 fixed to the structure just as the bin 16 reaches its final horizontal closed position. In this way, the lever 604 pivots in an opposite sense to free the bin 16 for forward movement so as to enable the wheel 506 to travel the full length of the track 518 into the parked position 602, in which the bin 16 is raised and the seal 600 Is compressed during the final closing motion of the drawer.
Figure 33(a) shows a bin 16 In a closed and raised position with the seal 600 compressed. The rear of the lever 604 Is firmly against the striker plate 612 so that the lever 604 Is disengaged from the stop plate 610 and tha wheel 506 is free
to move the full length of the track 518.
Figure 33(b) shows the bin 16 in a closed position but lowered so that the seal 600 is released. The rear of the lever 604 is still firmly against the striker plate 612 so that the lever 604 is disengaged and the bin movement is not limited. However, relative movement between the runner 510 and the bin 16 means that the wheel 506is now located at the mid-point of the wheel track 518.
Figure 33(c) shows the bin 16 In a partially open position with the seal 600 released. The rear of the lever 604 has moved away from the striker plate 612 so that the front of the lever 604 Is free to drop and has engaged with the stop plate 610, so that bin movement is now limited. The wheel 506 is still located at the midpoint of the wheel track 518 and the bin 16 can move forward or backward by a limited amount relative to the runner 510, as the wheel 506 travels along the inclined portions of the wheel track 518 either fbrwardly or rearwardly (or more precisely, as the trade travels with respect to the wheel). However, the load of the bin 16 and its contents biases the wheel 506 to the mid-point of the trad
Figure 33(d) shows the bin 16 in a partially open position with forward movement of the bin 16 relative to the runner 510, as the drawer Is being closed. The wheel 506 is now at the rearward limit of tiie wheel track 518 and the bin 16 is prevented from further forward movement with respect to the runner 510 by the engaging lever 604 bearing against the stop plate 610 on the runner 510. In effect, the bin 16 and the runner 510 are now locked together during continued closing movement of the drawer, until the rear end of the lever 604 encounters the striker plate 612 and releases the bin 16 for flirther forward movement with respect to the runner 510.
Figure 33(e) shows the bin 16 in a partialiy open position with rearward movement of the bin 16 relative to the runner 510« as would happen if the drawer is jerlced open. The wheel 506 is now located at the forward limit of the wheel track 518 and the bin 16 is prevented from further rearward movement with respect to the runner 510 by the wheel assembly 506 hitting the forward buffer 514.
Figure 33(d) and 33(e) show how movement of the bin 16 relative to the runner 510 causes vertical movement of the wheat trade 514, which bralcas the velocity of the bin 16. As this happens, the independent horizontal movement of the bin 16 increases the time allowed for this change in velocity to taica place, hence resulting In a smoother bin stop. Otherwise, depending upon how roughly a drawer Is handled in use, the bin 16 could come to a sudden stop at each end of travel, either closed-to-open or open-to-dosed, which can disturb stored objects and spill liquids within the bin 16.
i
Further to reduce rapid deceleration of the bin 16 at each end of travel, end-of-travel restraints can be used. For example, as the bin 16 is about to reach the final closed position, a flexible restraining plate on the runner can hit a striker plate on the structure that temporarily slows the runner and then releases it. Slowing the runner, but not the bin, allows the bin to move rearwardly independently of the runner, which absorbs some of the bin's momentum and so reduces inertlal effects upon the stored products as the bin thereafter comes to a halt.
Figures 34 to 36 show a flexible sprung angled restraining plate 614 attached by a hinge 616 to the underside of the runner 510. The plate Is essentially a strip formed in a right-angle and hinged at its apex between two mutually-orthogonal legs 618, 620. Normally one leg 618 lies horizontally against the underside of the runner 510 and the other leg 620 hangs vertically with the aid of a counter-balance
weight 622.
Figure 34 siiows th« restraining plate resisting movement in a restraining phase as it is forced past a striker plate 624 fixed to the structure. Continued movement of the runner SIO deflects the leg (shown by the dashed line) until It has deflected sufficiently to pass over the striker plate 624, thus ending the restraining phase. Figure 35 shows the runner 510 returning in the opposite direction; In this case, as the leg 620 reaches the striker plate, the entire restraining plate 614 pivots easily about the hinge 616 into the position shown by da^ed lines. Thus, in this direction, the restraining plate 614 offers no resistance to the drawer movement.
In practice, restraining plates 614 and striker plates 624 will be used in opposed pairs as shown in Figures 37(a) to 37(f). These drawings show the location of forward and rearward restraining plates 614 on the underside of the runner 510 and the associated striker plates 624 located on the structure. The forward striker plate 624 initiates the opening restraining end stop and the rearward striker plate 624 initiates the closing restraining end stop.
When the drawer opening is in a mid position shown in Figure 37(a), the restraining plates 614 do not encounter the associated striker plates 624. Figure 37(b) shows a drawer almost completely open with the forward restraining plate 614 engaging and deflecting around the forward striker plate 624, hence slowing the drawer as it nears the end of Its opening movement. Figure 37(c) shows the drawer completely open with the forward restraining plate 614 having passed over the striker plate 624. Conversely, Figure 37(d) shows the drawer almost completely closed with the rearward restraining plate 614 engaging the rearward striker plate 624 to slow bin movement near the end of the closing movement, and Figure 37(e) shows the drawer with the bin 16 fully closed, but not yet raised, and
the rearward restraining plate 614 having passed over the rearward striker plate 624. Figure 37(f) shows a drawer completely closed with the bin 16 raised and the seal compressed; again^ the restraining plates 614 do not encounter the associated strilcer plates 624.
Many variations are possible within the inventive concept. For example, it has already been said that movement of a lid can be linked to the movement of the associated bin or of a movable support for that bin, so that initial opening movement of the bin or Its support causes the lid to move apart firom the bin and, vice-versa, at or toward the end of a closing movement of the bin or Its support. The skilled reader will appreciate that the various bin transport mechanisms described above can be adapted and inverted to drive the vertical movement of a lid instead of the vertical movement of a bin, simply by acting upon an extension of the lid overhanging the bin rather ttian upon the bin itself.
The invention has wide-ranging applications and banefits for storing, handling, distributing, transporting and delivering Items In the right condition, notably:
precise variable temperature and humidity control that could even include
heating rather than merely cooling;
mechanical protection of stored Items;
sterile storage with minimal risk of cross-contamination;
the option of storage in partial vacuum conditions;
the option of storage in a preservative holding gas environment;
isolation of stored Items against vibration and agitation; and
containment of, or protection against, radiation and bio hazards.
In general, therefore, reference should be made to the appended claims and other general statements herein rather than to the foregoing specific description as indicating the scope of the invention. In interpreting the invention, it should be understood that although features of the illustrated embodiments have been described In combination with each other and although such combinations may have advantages of their own, many of those features can be applied independently. For example, the skilled reader will appreciate that the damper of Figures 32(a) to 32(0 could be used independently of a cold-storage appliance or other storage unit. So, those features are considered to be Independently patentable whether within or beyond the inventive concepts expressed herein.
WE CLAIM:
1. A storage unit including:
an open-topped drawer (4, 16);
a lid (22) adapted to close the open top of the drawer (4, 16
a structure supporting the drawer (4, 16) and the lid (22);
the drawer (4, 16) being mounted to the structure for movement relative thereto by support means (74) movable horizontally to support the drawer (4, 16) during a major horizontal component of movement to open the drawer (4, 16) and afford access to its interior or to close the drawer (4, 16); and
transport means (82, 86, 92) between the support means (74) and the drawer (4, 16) that responds to movement of the support means (74) to effect a minor vertical component of movement to separate the drawer (4, 16) from the lid (22) at the beginning of said horizontal component upon opening or to bring together the drawer (4, 16) and the lid (22) at the end of said horizontal component upon closing.
2. The unit of Claim 1, embodied as a cold storage appliance wherein: the drawer
(4, 16) is an open-topped insulating container; the lid (22) is insulating; and a
cooling means supported by the structure is adapted to cool the interior of the
container.
3. The unit of Claim 1 or Claim 2, wherein the minor vertical component takes place before the major horizontal component upon opening and after the major horizontal component upon closing.
4. The unit of Claim 1 or Claim 2, wherein the minor vertical component takes place during initial horizontal movement upon opening and during final horizontal movement upon closing.
5. The unit of any preceding Claim, further including locking means for releasably locking the transport means (82, 86, 92) to prevent vertical movement of the drawer (4, 16).
6. The unit of Claim 5, wherein the locking means is responsive to the position of the drawer (4, 16) in the horizontal direction and locks the transport means (82, 86, 92) during part of a range of movement of the support means (74) in that horizontal direction.
7. The unit of Claim 6, wherein the locking means unlocks the transport means (82, 86, 92) during initial horizontal movement upon opening and during final horizontal movement upon closing.
8. The unit of any preceding Claim, wherein the support means (74) is movable independently of the drawer (4, 16) and the transport means (82, 86, 92) is responsive to relative movement between the support means (74) and the drawer.
9. The unit of Claim 8, wherein the transport means (82, 86, 92) is responsive to movement of the support means (74) before the horizontal movement of the
drawer (4, 16) begins or to continued movement of the support means (74) after the horizontal movement of the drawer (4, 16) has been completed.
10. The unit of Claim 8 or Claim 9, wherein the transport means (82, 86, 92) includes a first part movable with the support means (74) and a second part movable with the drawer (4, 16), wherein relative movement between the parts accommodates said continued movement of the support means (74).
11. The unit of Claim 10, wherein said relative movement between the parts causes the minor vertical component of movement of the drawer (4, 16).
12. The unit of Claim 10 or Claim 11, wherein one part includes a ramp and the other part includes a ramp follower.
13. The unit of Claim 12, wherein the ramp is associated with stops or buffers to limit relative movement of the ramp follower.
14. The unit of Claim 12 or Claim 13, wherein the ramp follower is a wheel.
15. The unit of Claim 14, wherein the wheel is one of a pair of wheels, a first wheel of the pair being for rolling load-transmitting contact with the ramp and a second wheel of the pair being for rolling load-transmitting contact with the structure while also being in rolling load-transmitting contact with the first wheel.
16. The unit of Claim 14, wherein the wheel is supported by one or more auxiliary rollers opposed to the ramp.
17. The unit of Claim 12 or Claim 13, wherein the ramp follower is an opposed ramp such that relative sliding movement between the ramps during the major horizontal movement causes the minor vertical movement of the drawer.
18. The unit of Claim 17, wherein each ramp terminates in a peak at one end and a trough at the other end.
19. The unit of Claim 18, wherein relative movement between the ramps brings the peaks of the ramps into alignment with each other to bring the drawer (4, 16) and the lid (22) together.
20. The unit of Claim 18 or Claim 19, wherein relative movement between the ramps brings the peaks of the ramps into alignment with the opposed troughs to separate the drawer (4, 16) from the lid.
21. The unit of any of Claims 17 to 20 and including means for limiting relative movement between the ramps to transmit from one part of the transport means (82, 86, 92) to the other a force in the horizontal direction.
22. The unit of any of Claims 10 to 21, wherein the parts can be separated on removing the drawer (4, 16) from the support means (74).
23. The unit of any preceding Claim, wherein the support means (74) bears the weight of the drawer (4, 16) during movement of the drawer (4, 16) other than during initial movement in the horizontal direction upon opening and during final movement in the horizontal direction upon closing, the structure bearing the weight of the drawer (4, 16) directly during said initial and final movements and when the drawer (4, 16) is closed.
24. The unit of any preceding Claim, further comprising a damper extensible and
retractable in response to movement of the support means (74) with respect to
the structure.
25. The unit of Claim 24, wherein the damper has variable resistance to
movement of the support means.
26. The unit of Claim 25, wherein the resistance of the damper increases with increasing speed of movement of the support means.
27. The unit of Claim 25 or Claim 26, wherein the resistance of the damper increases approaching at least one end of its stroke.
28. The unit of any of Claims 24 to 27, wherein the damper resists movement of the support means (74) by pumping air through a restricted orifice.
29. The unit of any of Claims 24 to 28, wherein the damper comprises an outer cylinder sealed to a hollow and elongate piston movable within the outer cylinder to pressurise and depressurise air within the outer cylinder, the piston including a plurality of orifices spaced apart along its length and communicating with each other through the hollow interior of the piston, whereby the piston can be positioned within the outer cylinder to expose at least one of said plurality of orifices to the interior of the outer cylinder while simultaneously exposing at least one other of said plurality of orifices to atmosphere outside the outer cylinder.
30. The unit of any preceding Claim, further comprising restraining means to slow movement of the support means (74) or the drawer (4, 16) with respect to the structure.
31. The unit of Claim 30, wherein the restraining means is unidirectional in its effect.
32. The unit of Claim 30 or Claim 31, wherein the restraining means acts to slow the support means (74) or the drawer (4, 16) when the support means (74) or the drawer (4, 16) are at one or more predetermined locations in their range of movement with respect to the structure.
33. The unit of any of Claims 30 to 32, wherein the restraining means acts to slow the support means (74) or the drawer (4, 16) when the support means (74) or the drawer (4, 16) approach an end of said range or movement.
34. The unit of any of Claims 30 to 33, wherein the restraining means comprises a first part in fixed relation to the structure and a second part in fixed relation to the support means (74) or the drawer, the parts encountering one another during relative movement between the structure and the support means (74) or the drawer (4, 16) and at least one of the parts deflecting resiliently to allow the parts to pass one another upon continued relative movement.
35. The unit of any preceding Claim, wherein the support means (74) is fixed to a stabilising means to resist lateral sway of the drawer (4, 16) during the major component of movement.
36. The unit of Claim 35, wherein the stabilising means includes at least one extending member attached to the structure and being auxiliary to and movable with the support means.
37. The unit of Claim 36, wherein the extending member is relatively stiff in a generally horizontal direction transverse to the horizontal direction of opening or closing of the drawer.
38. The unit of Claim 37, wherein the or each extending member is laterally offset with respect to the horizontal direction of opening or closing.
39. The unit of any of Claims 35 to 38, wherein the extending member is a telescopic runner.
40. The unit of Claim 35, wherein the stabilising means includes pinions movable with the support means, the pinions being engaged with respective laterally-spaced racks extending in the horizontal direction of opening or closing.
41. A storage unit including:
an open-topped drawer (4, 16);
a lid (22) adapted to close the open top of the drawer (4, 16); and
a structure supporting the drawer (4, 16) and the lid (22);
the drawer (4, 16) being mounted to the structure for movement relative to the structure and the lid (22) by support means (74) movable horizontally to
support the drawer (4, 16) during a major horizontal component of movement to open the drawer (4, 16) and afford access to its interior or to close the drawer (4, 16); and
the lid (22) being mounted to the structure for movement relative to the structure and the drawer (4, 16) to separate the lid (22) from the drawer (4, 16) before said movement of the drawer (4, 16) upon opening or to bring together the drawer (4, 16) and the lid (22) after said movement of the drawer (4, 16) upon closing, the lid (22) being moved by a lid transport means between the support means (74) and the lid (22) that responds to movement of the support means (74) to move the lid (22).
42. The unit of Claim 41, embodied as a cold storage appliance wherein: the drawer (4, 16) is an open-topped insulating container; the lid (22) is insulating; and a cooling means supported by the structure is adapted to cool the interior of the container.
43. The unit of Claim 41 or Claim 42, wherein the lid (22) can be tilted relative to the structure and the drawer (4, 16).
44. The unit of Claim 43, wherein the lid (22) is hinged to the structure, the hinge defining a pivot axis horizontally spaced from the drawer (4, 16).
45. The unit of any of Claims 41 to 44, wherein the lid (22) is movable transverse to the direction of movement of the drawer (4, 16).
46. The unit of any of Claims 41 to 45, wherein the lid transport means moves the lid (22) before the drawer (4, 16) starts moving upon opening and after the
drawer (4, 16) has stopped moving upon closing.
47. The unit of any of Claims 41 to 46, wherein the support means (74) is movable independently of the drawer (4, 16) and the lid transport means is responsive to relative movement between the support means (74) and the drawer.
48. The unit of Claim 47, wherein the lid transport means is responsive to continued movement of the support means (74) after movement of the drawer (4, 16) has ceased.
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