Title of Invention	"IMPROVEMENTS RELATING TO DISC BRAKES"
Abstract	A disc brake comprising a brake housing which, in use, straddles a braking disc and is slidably mounted on a torque taking member, so as to be movable towards and away from the braking disc, the brake housing incorporating a brake actuator mechanism located on one side of the braking disc and arranged to directly engage a friction pad assembly carried by the torque taking member on one side of the braking disc, another friction pad assembly being likewise carried by the torque taking member on the other side of the braking disc, the brake actuator mechanism comprising at least one adjustable tappet assembly which can be engaged with the directly actuated friction pad assembly under the action of a lever and eccentric arrangement, the actuator assembly being located within a recess in the brake housing which recess is open towards the braking disc, and closed by a cover plate secured to the brake housing, characterised in that the tappet extends through a bearing aperture in the cover plate, which bearing aperture is formed by an inside wall of a bearing projection integrally formed with the cover plate, the bearing projection extending into the said recess of the brake housing over a major portion of the length of said tappet.

Title of Invention

"IMPROVEMENTS RELATING TO DISC BRAKES"

Abstract

A disc brake comprising a brake housing which, in use, straddles a braking disc and is slidably mounted on a torque taking member, so as to be movable towards and away from the braking disc, the brake housing incorporating a brake actuator mechanism located on one side of the braking disc and arranged to directly engage a friction pad assembly carried by the torque taking member on one side of the braking disc, another friction pad assembly being likewise carried by the torque taking member on the other side of the braking disc, the brake actuator mechanism comprising at least one adjustable tappet assembly which can be engaged with the directly actuated friction pad assembly under the action of a lever and eccentric arrangement, the actuator assembly being located within a recess in the brake housing which recess is open towards the braking disc, and closed by a cover plate secured to the brake housing, characterised in that the tappet extends through a bearing aperture in the cover plate, which bearing aperture is formed by an inside wall of a bearing projection integrally formed with the cover plate, the bearing projection extending into the said recess of the brake housing over a major portion of the length of said tappet.

Full Text	DESCRIPTION The present invention relates to a disc brake for use c u a cc.otor vehicle. More particularly, the present invention relates to a d sc brike which comprises a fixed torque taking or carrier member which str; idles a rotatable disc and carries both a directly and an indirectly actuated fripeniigs am^nged in the brake housing in a conventional manner. The brake h msins comprises a main body portion which contains an actuator mechanism, uid a bridge section integral therewith ie. the bridge section is bolted to t .e main body portion or integrally cast therewith so as to be of unitary cot struciion. The bridge section has an opening arranged radially of the disc, liroufh whic.i the friction pad assemblies can be inserted and removed from th torque taking member. The present invention relates more specifically to a d sc brike wherein the actuator mechanism comprises at least one, but preferabl \r twc tappet:; which are axially movable towards the brake disc to engage ;ind press tht directly actuated friction pad assembly against one side of tt ; bracing disc, the brake housing reacting and sliding on the said guide pins to ipply the indirectly actuated friction pad assembly to the other side of the braking disc. Actuation of the brake is by way of a lever and eccentric ar ange:nent wierein the eccentric arrangement engages the said tappets, pivotal E ovenient of -he lever causing the eccentric arrangement to move the tappets :owaris the braking disc. In the above described type of disc brake certain prol ilems occur in known constructions and it is the aim of the present inventic ;i to seek to overcome these problems to improve performance, life and rase of manufacture. One such problem relates to the support of the adjust ble tippets. In known constructions the adjustable tappets are supported in liearings in the brake housing. However, appreciating that each such tappet is an elongate assembly, it is usual for the bearing length to be less than oi'timum. As a result and noting; the fact that the geometry of the brake acn itor is such hat the eccentric arrangement which engages the tappets exerts i side load or each of the tappets when the brake is actuated, the tappets will, : n cerain circumstances, experience side forces such as to cause them o tilt. This tilting may be accentuated by a combination of the tappets extendit i as n result of lining wear and also as a result of the clearances which exis between the outer wall of the tappet and its respective bearings. Tilting of the tappets may result in unwanted taper wear of the friction pads, and in addition, undesirable wear on the related components of the tappets, supporting bearing : and adjacent mechanisms. The aim of this aspect of the present invention it to \ roduc e a new brake design which minimises if not overcomes, the above \ robleti. According to a first aspect of the present invention tl are i;. provided a disc brake comprising a brake housing which, in use, straddles a Draking disc and is slidably mounted on a torque taking member, so as t Thus, by virtue of this axially extended bearing the each tappei is better supported along its length, this improved support resiling lilting of the tappet, and improving actuation efficiency and adjuster cont D!. In a preferred embodiment the brake comprises two ; djustible tappet assemblies, each tappet being basically a two pan assembly, one part being a female part which is generally cylindrical with an enlarged one end region ".hereof, this enlarged diameter head engagin :, in ise, the directly actuated friction pad assembly. Extending from the othei end of the said female part, through said female part, is an axially exte uding blind bore within which one end region of me other part of the tappet; ssemsly ie. 'he male part, is threadedly engaged, the male part likewise having an enlarged head region which is, in use, engaged and acted upon by tin said eccentric arrangement. This enlarged head forms a bearing surface u;iich engages a wall of the axially extending cylindrical projection integrally forrr ed with the cover plate. Thus, appreciating that the major portion of the oui sr sui face of the female part of each tappet assembly is supported along its leigth by the inner wall of a said cylindrical projections, thus resisting tilting oi the tippet assembly, the engagement of the said bearing surface of the mlar^ed head of the said male part, with said cylindrical projection further ii proves tappet support and resists any possibility of tilting under the action D!' the eccemric arrangement. Preferably this enlarged head has at its radially out r edge region, an axially extending lip which extends towards the threaded en region of the said male part and forms a cylindrical inner bearing surface which engages around the outer wall formed by the said axially extending cylindric.il projection which is integrally formed with the cover plate. Alternatively the ree end region of the said cylindrical projection has an enlarged internal diami ter sc ction which engages around the outer peripheral bearing surface of the s id erlarged lead of the said male pan. Whilst the cylindrical projections or extensions of the cover plate may be cast with the cover plate to thus form a unitary construct: m, the cylindrical extensions may alternatively be at least partially formed by bearing sleeves which are secured to the cover plate. Thus the c bearing sleeves and cover plate may be made from different materia. he bearing sleeves may be made of a more suitable and probably more :xpeDsive bearing material such as a sintered bearing material and may be cast into ihe cover plate which can itself be formed as a die casting, thus optim ising Lhe construction. Further, whilst the axially extending lip of the head i ;gion of the preferred form of said male part of each tappet assembly mi \t be ntegral.y formed with the said male part to thus form a unitary constr ictior, the axially extending Up may alternatively be formed by an appropriate y dimensioned hollow cylindrical member in the form of an annulus, whicr can be secured to the outer surface of the head region of the said male part. Located between the two tappets is preferably an adjoin ster mechanism which is preferably secured in position in a further cylindric .1 projection of the cover plate, which further cylindrical projection is preferabl; cast with the cover plate to form a unitary construction. This adjuster me :holism incorporates a gear wheel which meshes with teeth provided on the respective heads of the respective male parts of said tappets so that rot ition of the gear wheel adjusts both tappets - rotation of the male parts cause the said female parts which are keyed in the cylindrical bearing projections, to move axiiilly through the bearing apertures towards the directly actuated i iction pad assembly. The adjuster mechanism is preferably actuated via ge ir teeth provided on the lever and eccentric arrangement, a lost motion mech* iiism being incorporated so that only after sufficient movement of the le >'er does a further gear wheel with which the gear teeth mesh, cause the first ti entioned gear wheel to rotate and the tappets to be adjusted. The or each said female part may be keyed in a resp 'Ctive cylindrical bearing projection by one or more splines extending axially )f the or each said female part and cylindrical bearing projection. The splines aay te provided on said female part with complementary grooves being prov led in. the irner wall of said cylindrical bearing projection. Alternatively th In an alternative construction, the or each said femal part may keyed in a respective cylindrical bearing projection by the b arms aperture on the or each cylindrical bearing projection having a non-circi iar/q lindricul transverse cross section and the or each female part having ;complimentary transverse cross section outer profile. Preferably the bearin ; apeitures a:id outer profile of the female parts are trilobal to prevent the f male parts from rotating in the respective said bearing apeitures. This trilobal construction is considered to be easier t marufactur; than a splined arrangement as it can be formed by a simple forgi g process on the said female part. Also if the bearing projection is formed b; a cylindrical bearing sleeve secured to the cover plate, the trilobal intern configuration is easily formed with the sleeve being manufactured by way ol sintering and therefore requiring a minimum amount of finishing. Further, in a two tappet construction the tendency fo the vappets to bind and/or tilt in the bearing apertures as formed by the be iring projections, as the brake experiences torque during brake applications, is minimised if the trilobal cross sections are arranged in the same orientation w ith ths apex of one lobe of each trilobal cross section being directed toward. the centre of rotation of the brake disc. If desired, the cover plate can incorporate other cylir ilrical, or other configuration, projections incorporating appropriately dimen ionec spigots or recesses within which various ancillary brake mechanisms e\. a pud wear sensor and/or manual retraction mechanism, can be located, md f 3r ease of manufacture and assembly of the brake such cover plate spij )ts and recesses can be producec. in mirror image duplication so that irrespec ive cf the wiy the cover plate is initially installed, appropriate locating spigots ind/or recesses will always be provided. A further problem arises with the basic construction f the present invention with regard to the provision of appropriate bearing within the Drake housing to support part cylindrical regions of the lever and t :centic arrangement. To explain, current brake designs which use a lever i nd ec centric as a method of applying the brake require the cylindrical surface; of tt.e eccer.tric to be rotatably arranged in a semi-cylindrical roller bearing. A bearing cage is in these prior constructions, seated in a complimentary profi ed fcrm machined in the cover pla-;e. However, in these brakes the cover plat With the brake design of the present invention where in the recess in the brake housing, which houses the actuator mechanism, opens towards the brake disc, problems occur with regard to machining of the requii d be;iring seats. To overcome this problem it is of course always possible to provide a fuither outer cover plate which can be machined as per prior art co structions. However this adds to the cost of the construction. Further, i lateral opening could be provided in the brake housing wall to permit acces The aim of this further aspect of the present inventic i is tierefon: to provide a disc brake construction of the type which the pref ;nt irvention relates, with appropriate bearing surfaces for the eccentric Tang;ment. According to a further aspect of the present inventior there is provided a disc brake comprising a torque taking member which, in u e, straddles a braking disc, a brake housing being siidably mounted on the torque taking member so as to be movable towards and away from the bre icing disc, the brake housing having a main body portion with a recess in \ hich an actuuor mechanism operable by a lever and eccentric arrangement, i mounted, tie recess opening towards the braking disc and being provided vith bearing seat members which are located in further respective recesses prart cf the lever and eccentric arrangement can engage. Preferably each bearing seat member is provided wit . a refining projection at one end of the part cylindrical bearing surface, this retaining projection, in use, extending over an end of a groove provu ;d in the lev:r and eccentric arrangement to axially retain a cylindrical force tr; asmiiting member which is arranged in said groove. Further, the two bearing seat members are each pref rably located in said further recesses so as to be freely rotatable therein aboi t an uxis perpendicular to the base of each recess. Thus, on assembl the bearing seat members can be loosely located in said further recesses wit! the bearing seat members being automatically correctly aligned with each ot er as and when the lever and eccentric arrangement is located thereon. Attentively, the bearing seat members may be of suitable design eg. tapered base re ;ions, to locate in suitably designed further recesses in the brake housing reces: , with initial operation of the brake applying pressure to each bearing seal men her via the lever and eccentric arrangement, and causing deformation ol the base regions and/or further recesses, to thus provide for a secure positive locat: on of the bearing seat members in the brake housing, correctly aligne Further, by manufacturing the bearing seat members its separate components from the brake housing, a more suitable mater i<. for the beaj.ing seat members can be selected without need to make vhole brake housing of same material. thus cost construction minimized any reduction in performance characteristics.> According to a further aspect of the present invention theri is provided a disc brake comprising a brake housing which straddles a I raking disc and is slidably mounted on a torque taking member which carries directly actuated and an indirectly actuated friction pad assembly located on uppos.te side faces of the braking disc, the brake housing being slidable to ware ; and away from the braking disc under the action of an actuator mechanism vliich is housed in' part of the brake housing on one side of the braking disc, t \c actiator mechanism comprising a pair of tappets which can engage ;, gainst the directly actuatable friction pad assembly, said tappets being axially :lidable towards the braking disc by a lever and eccentric arrangement, one end region of the lever having two lateral extensions, each extension forming a pai . cylindrical bearing surface which is supported on a bearing seat within the bra :e noising, a groove extending transversely of the lever between the said later il projections, said groove being eccentric relative to said part cylindrical b :arinj; surfaces and housing a force transmitting member towards each end i ijgion thereol', each force transmitting member engaging a respective tappei an intermedate member located in the groove between said two force transn litting members serving to correctly position said force transmitting member; with respect, to the tappers and carrying a gear drive which engages with an adjuster mechanism which can operate to adjust the length of the tap lets as necessary. Preferably the groove is of part cylindrical configura ion with the force transmission members being cylindrical members, the intemediats member being likewise cylindrical with the gear drive projecting laterally from the outer surface thereof. The groove may be semi-circular in t ansv* rse cro ;s section or less than a semi-circle in transverse cross section in which case the force transmitting members and the intermediate member a i merely be located laterally within the groove during installation. Alte natively, if the groove is larger than a semi-circle, the various members ha ;e to be axially slid into the groove. Whilst the force transmitting members are rotatable vithii the groove and are axially retained in position preferably by the intern sdiatc member and the retaining projection of each bearing seat member as de; ;ribed hereabove, the intermediate member is preferably fixed in the groove gainst rotation and/or axial movement by the surface of the lever adjacent the groove teing staked ie. deformed, at spaced locations along the axial lei jth o: the grsove. Alternatively, the intermediate member may be axially reti ined n the groove, eg. by the force transmitting members, though rotatable then in to a limited extent, the rotational limit being defined by the gear drive ei paging the sides of the groove, this limited rotation possibly providing for th The lever and lateral extensions are preferably cast w ,th the groov; required to locate the force transmitting members and interai ;diate member, being machined in one operation. Whilst the lever and later 1 extensions are preferably manufactured from cast steel, the intermediate mriiber could, if desired, be manufactured from any other suitable metal, eg. >;ven a plastics type of material. The above construction provides an improved weight reduced lever and eccentric arrangement which is easy to manufacture and am iged to advantageously provide a drive mechanism to the adjuster n: xhariism. According to a still further aspect of the present inve ution there is provided a disc brake comprising a torque taking member uliich straddles a braking disc, with a brake housing being slidably mounted ad assembly being likewise carried by the torque taking member on the c >posiie side of the braking disc, a seal assembly in the form of an annular cons ruction beini; secured between the brake housing, the head of the tappet and a siaft of the tappet, the annular seal assembly comprising a flexible annu ar boot member, one end region of which is secured in a groove in the head i igior of the tappet, the other end region being located between a surface of thj brake housing adjacent to the bearing aperture and part of a gener.il cylindrical retaining section which is engaged securely within an enlarged di The above still further aspect of the present inventio . provides a double tappet seal which is positively secured to the brake housing ;md which is relatively easy i:o instal. In a preferred construction of the eal assembly the annular lip seal is secured eg bonded, coaxially with the an .ular retaining member which is preferably made of metal. The combined lip seal and retaining member are, during construction of the brake, fitted intD an enlarged end region of me bearing aperture, prior to the tappet beinj inse:ted in the bearing aperture. The retaining member being an interfere ;ce fi; in the enlarged end region of the bearing aperture. Then the tapj ;t wiih the flexible boot member secured to the head region of the tappet, is h jertec; through the lip seal and thus the bearing aperture, the flexible boot me: iber lien be .ng secured between the retaining member and an adjacent surl ice o: the brike housing. In an alternative embodiment wherein the flexible bo >t member is also secured to the retaining member so that the boot member, li'.' seal and retaining member form a unitary construction, the flexible b :tot member is secured to the head region of the tappet with the lip seal loc i.ted en the tappet shaft, prior to installation of the tappet in the bearing apertu :e. On insertion of the tappet into the bearing aperture the retaining member >:an he pressed into the enlarged end region of the bearing aperture as an i;iterfe:-ence fit, securing the lip seal in the desired position relative to the ta :pet shaft wall as well as retaining the flexible boot in the desired position, The above individual aspects of the construction of ti le present invention improve the performance characteristics and ease nf maiufacture and can be adopted in combination with each other or individual iy as desired Accordingly, the present invention relates to a disc brake comprising a brake housing which, in use, straddles a braking disc and is slidably mounted on a torque taking member, so as to be movable towards and away from the braking disc, the brake housing incorporating a brake actuator mechanism located on one side of the braking disc and arranged to directly engage a friction pad assembly carried by the torque taking member on one side of the braking disc, another friction pad assembly being likewise carried by the torque taking member on the other side of the braking disc, the brake actuator mechanism comprising at least one adjustable tappet assembly which can be engaged with the directly actuated friction pad assembly under the action of a lever and eccentric arrangement, the actuator assembly being located within a recess in the brake housing which recess is open towards the braking disc, and closed by a cover plate secured to the brake housing, characterised in that the tappet extends through a bearing aperture in the cover plate, which bearing aperture is formed by an inside wall of a bearing projection integrally formed with the cover plate, the bearing projection extending into the said recess of the brake housing over a major portion of the length of said tappet. The present invention will now be further described, by way of example, with reference to the accompanying drawings, in 'i'hich - Fig. 1 is a partially cut-away view of one embodime lit of a disc brake constructed according to the present invention; Fig. 1A is a cross sectional view of the brake showr in F:g. 1; Fig. IB is a cross-sectional view of part of a modifi :d embodiment .of the present invention; Fig. 2 is a partially cut-away view of a further emb Fig. 3 i;> a partially cat-away view of a still further embodiment of a disc brake constructed according to the present invention; Fig. 4 is a cross sectional view of part of a still furtf ;Jr modified embodiment of the present invention; Fig. 5 is a cross sectional view taken along line A-A in Fig. 4; Fig. 6 is a view of the brake with the cover plate rei \oved, illustrating the mirror image duplication of available recesses; Fig. 7 is a perspective, partially cut-away view of a :earkg seat member according to a further aspect of the present inventic :i; Fig. S is an inverted plan view of the bearing seat m :;mber of Fig. 7; Fig. 9 is a rear view of a lever arrangement as utilis Fig. 10 is a front view of the lever in Fig. 9; Fig. 11 is a side view of the lever of Figs. 9 and 10 Fig 12 is a plan view of the intermediate member u ed with the 'ever of Figs. 9 to 11; Fig. 13 is an end view of the intermediate member Fig. 14 is a cutaway partial view of any one of the * Tibociments of Figs 1 to 3, illustrating the seal assembly of the present inv ntion, in enlarged detail. Referring to the embodiment of me present inventioi illustrated in Figs. 1 and 1A of the accompanying drawings, the brake basicall corr prises i. brake housing generally designated 1, which straddles a braking disc 3 and is slidably mounted on a torque taking member 5 by virtue of guide p: is (not illustrated) in a conventional manner. The brake housing 1 comprises a main body section i' whiih is be died to a bridge section 9. Alternatively, the main body section .nd the bridge section can be integrally cast as a unitary construction, the riain body section having a cavity or recess 11 within which a brake actuator i lechanism generally designated 13 is located, the cavity or recess in th1 brai.e housing being open towards the braking disc 3 to allow for the locat on 01 the actuator mechanism 13 during manufacture and assembly. The actuator mechanism 13 comprises a pair of tappt assemblies 15, 17 which are psjallel to each other and which extend throuj i bearing apurtures 19, 21 provided in a cover plate 23 which is secured to the brake housing 1 and which closes off the said cavity/recess 11, each tappet 'ress this friction pad assembly 25 against one side of the braking disc 3. Cc itinund pressure causes the brake housing 1 to slide on the guide pins relativ; to tie torque taking member 5 and braking disc 3, with the bridge sectio . 9 pressing on an indirectly actuatable friction pad assembly 29 which engage the opposite side of the braking disc 3. Each tappet assembly 15, 17 comprises an elongate emah part 31 which has an enlarged head region 33 which can engage or act upon the directly actuatable friction pad assembly 25. The other end i-egioi 35 of said female part 31 has a blind bore 37 which extends axially thi mgh the said female part 31. Threadedly interengaged in said blind bore '. 1 is n male part 39 of each tappet assembly 15, 17, the outer end region of s lid rr ale part 39 being formed with an enlarged head region 41 on which the lever and eccentric arrangement 27 acts. As evident in Fig. 1 of the accompanying drawings t le co/er plate 23 is provided with a cylindrical extension 43 projecting perpei'iicularly therefrom and into the cavity 11 of the brake housing 1, the innei wall of this cylindrical extension 43 forming a supporting bearing surfac ; for the Outur wall of the female part 31 of each tappet assembly 15, 17, t te cy indrica; extension 43 supporting said female part 31 for the majority of its length and thus limiting, if not preventing, tilting of the female part 31 of thi tapper assembly 15,17 in its bearing support. Further, the enlarged head region 41 of the male par 39 cf each tappet assembly 15,17 has a cylindrical lip extension 45 which ext removal or miiLmising of tapered wear on the friction pad a itsemblies 25, 29, and improving brake and adjuster efficiency. As seen in Fig. 1 of the accompanying drawings, tht ferns le part 31 of each tappet assembly 15, 17 is keyed as at 47 for solely axi .1 movement within the cylindrical projection 43 of the cover plate 23, rotation i if the male part 39 of each tappet assembly 15,17 thus solely causing axial movJinen: of the female part 31 thereof. Further, the cylindrical lip 45 carries an annular was ter 4!) against which one end of a coiled spring 51 engages, the other end .ingaging the cover plate 23. This spring 51 thus presses the male part 39 of ez ;h tappet assembly 15, 17 against the lever and eccentric arrangement 27. To produce axial adjustment of each tappet assembly 15, ] 7 rotation of the male part 39 is required and this is effected via teeth 53 provided on the outer surface of the cylindrical lip 45, a gear wheel 55 of a,' adjuster mechanism 57 engaging the teeth 53 on the respective male Darts 39 of tie respective tappet assemblies 15, 17. The adjuster mechanism 57 is likewise carried in a r cess 59 defried by a cylindrical projection 61 of the cover plate 23, this cylind ical iupport 61 positively retaining and securing the position of the adjuster mechanism ;>7 within the brake housing 1, and thereby ensuring improved positioning with respect to the male part 39. Additionally, further recessed projections (see Fig. ( I can be provided ie. cast in the cover plate 23, to facilitate positive retention md jositioning of various mechanisms eg. a pad wear sensor mechanism. Preierably, such recessed projections are provided in a mirror image duplicaiton (see ghosted circles 44,46 in Fig. 4) so that during assembly of the braki the cover plate 23 will readily fit all of the desired features whichever way .it is located. The adjuster mechanism 57 comprises the gear whee 55 which is fixedly mounted on core part 63 which is freely rotatably m;>untei on rotatable shaft 65, a further cylindrical core part 67 being fixed on si id shaft 65 against rotation relative thereto, with a wrap spring 69 engaging th wrap spring 69 which provides a lower drag torque between the core pans 63, 67 in the reverse direction of rotation. In a modified form of the disc brake constructed ac& irding to the present invention and shown in Fig. IB, wherein the referer >:e numerals used in Fig. 1 are again used to indicate equivalent parts, the freet 15,17 engages, the inside wall of said free end region 43' thus supporting the male part of the tappet. This enlarged head region 41 is providec with the teeth 53 which mesh with the adjuster mechanism via an opening 43' in tie wall of the said free end region, the spring 51 being likewise within the cylirdrical projection between the enlarged head region 41 and a shouh ar fo -med by the stepped bore in the cylindrical projection 43. In a further modified form of the disc brake of the p esent invention as shown in Fig. 2 of the accompanying drawings, wherein tte refetence numerals used in Fig. 1 are again used to indicate equivaler. part;, the said cylindrical extensions 43 of the cover plate 23 are reduced i i axie 1 length as compared to those of the Fig. 1 construction, with a bearins cylindrical liner 75 being secured therein and extending for the major part o the length of the female part 31 of each tappet assembly 15,17, the cylindric; I lip 4-5 of the male pan 39 of each tappet assembly 15, 17 engaging over he fr;e end region of the respective bearing liners 75. By this construction, th bearing liner 75 can be made of a more suitable, usually more expensive be; ring :naterial as opposed to the usual cast material construction of the cover date 13, thereby minimising the cost of construction. In a still further embodiment of the present tnventior as illustrated in Fig. 3 of the accompanying drawings, wherein the referenci numerals used in Fig. 1 are again used to indicate equivalent pans, whilst the cylindrical extensions 43 of the cover plate 23 are as provided in the ei ibodiment ol' Fig. 1, the cylindrical lip 45 on the enlarged head region 41 of : :& male part 39 of the respective tappet assemblies 15, 17, is formed by an ariMilar membet 77 which is secured around the enlarged head region 41 of eac:. mali; part 39, this annular member 77 forming the required cylindrical lip whi :h engages over the cylindrical extension 43 of the cover plate 23 to support the male part 3S' of each tappet assembly 15,17, the outer surface of each annul ir member 77 being provided with appropriate teeth 79 which mesh with Hie geir wheel 55 of the adjuster mechanism 57. This modified construction »:an piovide advantages in manufacture particularly with the choice of miterials bearing in mind wear etc. with regard to the meshing of the teeth 79 A 1th the gear wheel ' 55 of the adjuster mechanism 57. Whilst the male and female parts 31, 39 in each of i le embodiments of Figs. 1, 2 and 3 of the accompanying drawings are keyed t igeuVr by an axially extending spline/groove (see 47 in Fig. 1), Figs. 4 ind 5 of the accompanying drawings show a modified form of the prese it invention wherein the female part 31 of each tappet assembly 15, 17 .s keyed for solely axial movement within the bearing projection 43 of the CON isr pU.te 23, by the outer profile of die transverse cross section of the female pa : 31 being trilobal and being located in a complimentary trilobal transverse cro! s seciion bearing aperture 43' in the bearing projection 43 of the cover plate . 3. Tbus the female part 31 is an axially slidable fit on the bearing apertu re 43 but cannot be rotated relative thereto, rotation of the axially secure mal: pan 39 thereby causing axial movement of the female part in the bearing ap :rture 43'. Further the trilobal cross sections of the two tappet a range unents 15, 17 are arranged in the same orientation with the apex 43" of 01 ie lobe of each trilobal cross section being directed towards the centre of ro ition of the brake disc 3 as shown in Fig.4 of the accompanying drawings. B; this construction the tendency for the tappets 15, 17 to bind and/or tilt in the ^earhg apertures 43', as the brake experiences torque during brake applications, is minimised. This trilobal construction is considered easier to man facto re than, for example, a spliued arrangement such as shown at 47 in Fig. 1, as it can be formed by a simple forging process on said female part 31. Also if the bearing aperture 43' is formed by a bearing sleeve 75' secursd to the cover plate 23, as shown in Figs. 4 and 5, the trilobal construction is easily foimed with the sleeve 75' being manufactured by way of sintering md therefore: requiring a minimum amount of finishing. If desired, the s itereil bearing 75' may be cast into the die cast cover plate 23. With regard to the lever and eccentric arrangement 1 1 in each of the embodiments of Figs. 1, 2 and 3 of the accompanying draw .ngs us best seen in Figs. 9 to 13, this comprises an elongate lever 81, one upr. :r eni region 83 of the lever 81 being engageable by actuating means such as a ineumatic actuator, whilst the other, lower end region 85 has two opp Eccentric to the centre of curvature of the respective mrved bearing surfaces 89 of the operational bearing shaft, and generally o iposile to said bearing surfaces is an elongate groove 95 which is machine( alon; the length of said operational bearing shaft. This groove 95 has a pail cylindrical configuration which is less than semi-circular in transverse located at opposite end regions of the groove 95 with an int rmediate member 99 located therebetween, the intermediate member 99 preve .ting ixial movement of the force transmitting members 97 towards ea h Other. Ths gear drive 7? previously referred to is a lateral extension of this intermediate member 99 and the intermediate member 99 is secured agai ist rotation or axial movement in the groove 95 by adjacent regions of the open .tiona, bearing shaft being deformed ie. staked, adjacent to the edge of the groo e 95. Alternatively, the intermediate member 99 may be allowed o route to a limited degree, rotation being limited by the lateral gear dri e 73 engaging the edges of the groove 95, this limited rotation providing for tl ie required lost motion in the adjuster mechanism 57 to which the gear driv : 73 is meshed. Whilst the intermediate member 99 is made of cast s eel it may alternatively, if desired, be made of any suitable other meta lie material or even a plastics material. As referred to hereabove the curved bearing surfaces 89 ai opposite end regions of the operational bearing shaft are supported on be >rings 91 which are mounted on complimentarily curved surfaces 101 in bearing seat members 93 which are themselves located in appropriate recesses 109 in the bDttom face of the cavity 11 in the brake housing 1, These bearing seat m mibers 93 ara best illustrated in Figs. 7 and 8 wherein it will be seen that eact bearing seat member 93 presents a curved bearing support surface 101, it one end of which is provided a retaining section 105. As evident from Figs. L, 2 und 3, these retaining sections 105 extend over the ends of the groove 9 in the operational bearing shaft to hold the force transmitting members 97 in he respective end regions of the said groove 95. As shown in Fig.8 the base 107 of each bearing sea member 93 is generally of circular/cylindrical configuration and is freely 'otatably located in a complimentary recess 109 in the base of the cavity 11. T tus, curing installation, when the bearing operational shaft and bearing 91 are located on the respective bearing seat members 93, the bearing seat m '-mbe:'S 93 rotate in their respective recesses 109 to become accurately and con toy aligned with each other for subsequent use. In a modified form of construction, the base of each bearing seat member 93 is shaped eg, tapered, so as to overly the edges >f the recesses 109 hi the base of the cavity 11 hi the brake housing 1. Thus, > 'hilst the respective bearing seat members 93 can be generally located in positio: , wh;n the bver and eccentric arrangement 27 is located on the respective be aring seat members 93, the bearing seat members 93 rotate to correctly and acci irately align with each other, and then on initial use of the brake, the bearing seat members 93 are deformed into the respective recesses 109 to firmly and wsiti/ely secure the bearing seat members 93 as an integral part of the brake housing 1. Alternative possible shapes and configurations are of course possible for the bearing seat members 93 and the recesses 109 to provide to this positive and secure attachment of the bearing seat members 93 to the Ice housing 1. Further these bearing seat members 93 facilitate mai ifacture as ii would be difficult to machine appropriate bearing support s irfaces 101 iii the base region of the cavity 11 in the brake housing 1 without the p'ovisior. of an ' outer cover plate, or a lateral opening which would then require :o be sealed. Also, by the provision of separate components as bearing a at members ?3, a more suitable material can be selected for the construction of the bearing seat members 93 without the need for the whole brake housing i to be manufactured from the selected material. Thus manufactur og costs can be reduced in two different ways by virtue of the provision of the separate bearing seat members 93. Further, as evident from Figs. 1, 2 and 14 of the ace ompaiying drawings, a positive and secure seal assembly 110 is provide ii for each tappet assembly 15, 19. Each such seal assembly 110 comprises a.: annular flexible boot 111, one end 113 of which is beaded and resiliency an ]. finely engaged in an annular recess 115 around the head region of the fema le pait 31 of the tappet assembly 15,17. The other end region of the flexible boot 111 is likewise beaded 117 and engages between an upper surface >f the cover plate 23 and a parallel surface of an annular retaining member 11 :i which is of stepped configuration in transverse cross section. A furthe lip seal 119 is secured eg. bonded, to the inner edge of the retaining meml er 118 so as to project inwardly thereof. A middle region of this retaining member 118 is generally cylindrical and engages in an enlarged diameter r With the above sealing assembly 110 construction, assembly is facilitated and manufacturing costs thereby reduced, the an ular :ip seal 119 is secured eg bonded, coaxially with the annular retaining me aber 118 which is preferably made of metal. During construction of the brak :, the combined lip seal 119 and retaining member 118 are fitted into the enlar ed end region 121 of the bearing aperture 19, prior to the tappet 15,17 being in the bearing aperture 19, the retaining member 118 being an in ; e fit in the enlarged end region 121 of the bearing aperture 19. Then Lhe teppet 15,17 with the flexible boot member 111 secured to the head regie i 33 ->f the famale part 31 of the tappet 15,17, is inserted through the lip seal J19 aid thus ihe bearing aperture 19, the flexible boot member 111 then beir i» secured between the retaining member 118 and an adjacent surface of the co^ ir plJite 23, ID an alo;nnative embodiment (not illustrated) the fie; ible l»oot member 111 is also secured eg bonded, to the retaining member 118 so that the boot member 111, lip seal 119 and retaining member US form a unitary construction, the sealing assembly 110 can be attached to th:; female part 31 of a tappet 15,17 assembly with the bead 113 being securely e tgaged in the annular recess 115 in the head region 33 of the said female part :•!, after the retaining member 118 and sealing lip 119 have been slid a dally along trie outer surface of the said female part 31. Then, the female i art 3.. of the tappet assembly 15,17 can be inserted into the bearing aperture 1:p together with the seal assembly 110, and the cylindrical portion of the retain.' The above construction of disc brake has consideralie pe .formarce advantages together with advantages respect of the ease of isseir bly ie. reduce manufacturing costs. We Claim: 1. A disc brake comprising a brake housing (1) which, in use, straddles a braking disc (3) and is slidably mounted on a torque taking member (5), so as to be movable towards and away from the braking disc (3), the brake housing (1) incorporating a brake actuator mechanism (13) located on one side of the braking disc (3) and arranged to directly engage a friction pad assembly (25) carried by the torque taking member (5) on one side of the braking disc (3), another friction pad assembly (29) being likewise carried by the torque taking member (5) on the other side of the braking disc (3), the brake actuator mechanism (13) comprising at least one adjustable tappet assembly (15; 17) which can be engaged with the directly actuated friction pad assembly (25) under the action of a lever and eccentric arrangement (27), the actuator assembly (13) being located within a recess (11 ] in the brake housing (1), which recess (11) is open towards the braking disc (3), and closed by a cover plate (23) secured to the brake housing (1), characterised in that the tappet (15; 17) extends through a bearing aperture (19; 21) in the cover plate (23), which bearing aperture (19; 21) is formed by an inside wall (143) of a bearing projection (43) integrally formed with the cover plate (23), the bearing projection extending into the said recess of the brake housing (1) over a major portion of the length of said tappet (15; 17). 2. A disc brake as claimed in claim 1, whefe»jsaid at least one tappet assembly (15; 17) comprises an elongate female part (31) having an axially extending blind bore (32) into which an elongate male part (39) is threadedly engaged. 3. A disc brake as claimed in claim 2, wherein the said elongate female part (31) has an enlarged diameter head (33) at one end region thereof, this enlarged diameter head (33) engaging, in use, the directly actuated friction pad assembly (25), the elongate male part (39) likewise having an enlarged head (41) which is, in use, engaged and acted upon by the said eccentric arrangement (27). 4. A disc brake as claimed in claim 3, wherein the said enlarged head of the said male part (41) forms a bearing surface which engages a wall of the axially extending projection (43) integrally formed with the cover plate (23) . 5. A disc brake as claimed in claim 4, wherein the said enlarged head (41) of the said male part (39) has an axially extending lip (45) at its outer edge region, which lip extends towards the threaded end region (41) of the male part (39) and forms a cylindrical inner bearing surface (89) which engages around an outer cylindrical wall region of said axially extending projection (43) integrally formed with the cover plate (23). 6. A disc brake as claimed in claim 5, wherein the said axially extending lip (45) and the enlarged head (41) of the male part (39) are of unitary construction. 7. A disc brake as claimed in claim 5, wherein the said axially extending lip (45) is formed by a hollow cylindrical member secured to the outer surface of the enlarged head region (41) of the male part (39). 8. A disc brake as claimed in claim 4, wherein the said free end region of said projection (43) has an enlarged internal diameter section which engages around an outer peripheral bearing surface provided in the enlarged head (41) of said male part (39). 9. A disc brake as claimed in any of the preceding claims , wherein the said projection (43) integrally formed with the cover plate (23) is formed by a bearing sleeve secured to the cover plate. 10. A disc brake as claimed in claim 9, wherein the said bearing sleeve (43) is constructed of a different material from the cover plate (23 ). 11. A disc brake as claimed in claim 10, wherein the said bearing sleeve (43) is made of a sintered bearing material and is cast into the cover plate (23) which is itself die cast. 12. A disc brake as claimed in any of claims 1 to 8 , wherein the said projection (43) and said cover plate (23) are of unitary construction. , 13. A disc brake as claimed in any of the preceding claims, wherein the said bearing aperture (143) in the said projection (43), has a non- circular transverse cross section into which the said female part (31) with a complimentary outer profile transverse cross section, engages. 14. A disc brake as claimed in claim 13, wherein the said bearing aperture (143) in the said projection (43), has a trilobal transverse cross section and the said female part (31) has a complimentary trilobal outer profile transverse cross section. 15. A disc brake as claimed in any of claims 1 to, 13, wherein there are two tappet assemblies (15; 17) between which an adjuster mechanism (57) is located. 16. A disc brake as claimed in claim 15, wherein the said adjuster mechanism (57) incorporates a gear wheel (55) which meshes with teeth (53) provided on respective head regions of the respective male parts (39) of said tappet assemblies (15; 17), whereby rotation of the gear wheel (55) causes rotation of the male parts (39) and resultant axial movement of said female parts (31) of said tappet assemblies (15; 17). 17. A disc brake as claimed in claim 16, wherein the said adjuster mechanism (57) is operable by gear teeth (63) provided on the lever and eccentric arrangement (27), which gear teeth engage with said gear wheel (55) with a lost motion mechanism being incorporated to thus only allow said gear wheel (55) to rotate to adjust the tappet assemblies (15; 17) when the lever has been moved through a distance. 18. A disc brake as claimed in any of claims 15 to 17, wherein the said adjuster mechanism (57) is secured in position on the cover plate (23), in a further bearing projection (61) integrally formed with the cover plate (23). 19. A disc brake substantially as herein described with reference to and illustrated in the accompanying drawings.

Full Text

DESCRIPTION
The present invention relates to a disc brake for use c u a cc.otor vehicle.
More particularly, the present invention relates to a d sc brike which comprises a fixed torque taking or carrier member which str; idles a rotatable disc and carries both a directly and an indirectly actuated fripeniigs am^nged in the brake housing in a conventional manner. The brake h msins comprises a main body portion which contains an actuator mechanism, uid a bridge section integral therewith ie. the bridge section is bolted to t .e main body portion or integrally cast therewith so as to be of unitary cot struciion. The bridge section has an opening arranged radially of the disc, liroufh whic.i the friction pad assemblies can be inserted and removed from th torque taking member.
The present invention relates more specifically to a d sc brike wherein the actuator mechanism comprises at least one, but preferabl \r twc tappet:; which are axially movable towards the brake disc to engage ;ind press tht directly actuated friction pad assembly against one side of tt ; bracing disc, the brake housing reacting and sliding on the said guide pins to ipply the indirectly actuated friction pad assembly to the other side of the braking disc. Actuation of the brake is by way of a lever and eccentric ar ange:nent wierein
the eccentric arrangement engages the said tappets, pivotal E ovenient of -he lever causing the eccentric arrangement to move the tappets :owaris the braking disc.
In the above described type of disc brake certain prol ilems occur in known constructions and it is the aim of the present inventic ;i to seek to overcome these problems to improve performance, life and rase of manufacture.
One such problem relates to the support of the adjust ble tippets. In known constructions the adjustable tappets are supported in liearings in the brake housing. However, appreciating that each such tappet is an elongate assembly, it is usual for the bearing length to be less than oi'timum. As a result and noting; the fact that the geometry of the brake acn itor is such hat the eccentric arrangement which engages the tappets exerts i side load or each of the tappets when the brake is actuated, the tappets will, : n cerain circumstances, experience side forces such as to cause them o tilt. This tilting may be accentuated by a combination of the tappets extendit i as n result of lining wear and also as a result of the clearances which exis between the outer wall of the tappet and its respective bearings. Tilting of the tappets may result in unwanted taper wear of the friction pads, and in addition, undesirable wear on the related components of the tappets, supporting bearing : and adjacent mechanisms.
The aim of this aspect of the present invention it to \ roduc e a new brake design which minimises if not overcomes, the above \ robleti.
According to a first aspect of the present invention tl are i;. provided a disc brake comprising a brake housing which, in use, straddles a Draking disc and is slidably mounted on a torque taking member, so as t Thus, by virtue of this axially extended bearing the each tappei is better supported along its length, this improved support resiling lilting of the tappet, and improving actuation efficiency and adjuster cont D!.
In a preferred embodiment the brake comprises two ; djustible tappet assemblies, each tappet being basically a two pan assembly, one part being a female part which is generally cylindrical with an enlarged one end region ".hereof, this enlarged diameter head engagin :, in ise, the directly actuated friction pad assembly. Extending from the othei end of the said female part, through said female part, is an axially exte uding blind bore within which one end region of me other part of the tappet; ssemsly ie. 'he male part, is threadedly engaged, the male part likewise having an enlarged head region which is, in use, engaged and acted upon by tin said eccentric arrangement. This enlarged head forms a bearing surface u;iich engages a wall of the axially extending cylindrical projection integrally forrr ed with the cover plate.
Thus, appreciating that the major portion of the oui sr sui face of the female part of each tappet assembly is supported along its leigth by the inner wall of a said cylindrical projections, thus resisting tilting oi the tippet assembly, the engagement of the said bearing surface of the mlar^ed head of the said male part, with said cylindrical projection further ii proves tappet support and resists any possibility of tilting under the action D!' the eccemric arrangement.
Preferably this enlarged head has at its radially out r edge region, an axially extending lip which extends towards the threaded en region of the said male part and forms a cylindrical inner bearing surface which engages around the outer wall formed by the said axially extending cylindric.il projection which is integrally formed with the cover plate. Alternatively the ree end region of the said cylindrical projection has an enlarged internal diami ter sc ction which engages around the outer peripheral bearing surface of the s id erlarged lead
of the said male pan.
Whilst the cylindrical projections or extensions of the cover plate may be cast with the cover plate to thus form a unitary construct: m, the cylindrical extensions may alternatively be at least partially formed by bearing sleeves which are secured to the cover plate. Thus the c bearing sleeves and cover plate may be made from different materia. he bearing sleeves may be made of a more suitable and probably more :xpeDsive bearing material such as a sintered bearing material and may be cast into ihe cover plate which can itself be formed as a die casting, thus optim ising Lhe construction.
Further, whilst the axially extending lip of the head i ;gion of the preferred form of said male part of each tappet assembly mi \t be ntegral.y formed with the said male part to thus form a unitary constr ictior, the axially extending Up may alternatively be formed by an appropriate y dimensioned hollow cylindrical member in the form of an annulus, whicr can be secured to the outer surface of the head region of the said male part.
Located between the two tappets is preferably an adjoin ster mechanism which is preferably secured in position in a further cylindric .1 projection of the cover plate, which further cylindrical projection is preferabl; cast with the cover plate to form a unitary construction. This adjuster me :holism incorporates a gear wheel which meshes with teeth provided on the respective heads of the respective male parts of said tappets so that rot ition of the gear wheel adjusts both tappets - rotation of the male parts cause the said female
parts which are keyed in the cylindrical bearing projections, to move axiiilly through the bearing apertures towards the directly actuated i iction pad assembly.
The adjuster mechanism is preferably actuated via ge ir teeth provided on the lever and eccentric arrangement, a lost motion mech* iiism being incorporated so that only after sufficient movement of the le >'er does a further gear wheel with which the gear teeth mesh, cause the first ti entioned gear wheel to rotate and the tappets to be adjusted.
The or each said female part may be keyed in a resp 'Ctive cylindrical bearing projection by one or more splines extending axially )f the or each said female part and cylindrical bearing projection. The splines aay te provided on said female part with complementary grooves being prov led in. the irner wall of said cylindrical bearing projection. Alternatively th In an alternative construction, the or each said femal part may keyed in a respective cylindrical bearing projection by the b arms aperture on the or each cylindrical bearing projection having a non-circi iar/q lindricul transverse cross section and the or each female part having ;complimentary transverse cross section outer profile. Preferably the bearin ; apeitures a:id outer profile of the female parts are trilobal to prevent the f male parts from rotating in the respective said bearing apeitures.
This trilobal construction is considered to be easier t marufactur; than
a splined arrangement as it can be formed by a simple forgi g process on the said female part. Also if the bearing projection is formed b; a cylindrical bearing sleeve secured to the cover plate, the trilobal intern configuration is easily formed with the sleeve being manufactured by way ol sintering and therefore requiring a minimum amount of finishing.
Further, in a two tappet construction the tendency fo the vappets to bind and/or tilt in the bearing apertures as formed by the be iring projections, as the brake experiences torque during brake applications, is minimised if the trilobal cross sections are arranged in the same orientation w ith ths apex of one lobe of each trilobal cross section being directed toward. the centre of rotation of the brake disc.
If desired, the cover plate can incorporate other cylir ilrical, or other configuration, projections incorporating appropriately dimen ionec spigots or recesses within which various ancillary brake mechanisms e\. a pud wear sensor and/or manual retraction mechanism, can be located, md f 3r ease of manufacture and assembly of the brake such cover plate spij )ts and recesses can be producec. in mirror image duplication so that irrespec ive cf the wiy the cover plate is initially installed, appropriate locating spigots ind/or recesses will always be provided.
A further problem arises with the basic construction f the present invention with regard to the provision of appropriate bearing within the Drake housing to support part cylindrical regions of the lever and t :centic arrangement.
To explain, current brake designs which use a lever i nd ec centric as a method of applying the brake require the cylindrical surface; of tt.e eccer.tric to be rotatably arranged in a semi-cylindrical roller bearing. A bearing cage is in these prior constructions, seated in a complimentary profi ed fcrm machined in the cover pla-;e. However, in these brakes the cover plat With the brake design of the present invention where in the recess in the brake housing, which houses the actuator mechanism, opens towards the brake disc, problems occur with regard to machining of the requii d be;iring seats. To overcome this problem it is of course always possible to provide a fuither outer cover plate which can be machined as per prior art co structions. However this adds to the cost of the construction. Further, i lateral opening could be provided in the brake housing wall to permit acces The aim of this further aspect of the present inventic i is tierefon: to provide a disc brake construction of the type which the pref ;nt irvention relates, with appropriate bearing surfaces for the eccentric Tang;ment.
According to a further aspect of the present inventior there is provided a disc brake comprising a torque taking member which, in u e, straddles a braking disc, a brake housing being siidably mounted on the torque taking member so as to be movable towards and away from the bre icing disc, the brake housing having a main body portion with a recess in \ hich an actuuor mechanism operable by a lever and eccentric arrangement, i mounted, tie recess opening towards the braking disc and being provided vith bearing seat members which are located in further respective recesses prart cf the lever and eccentric arrangement can engage.
Preferably each bearing seat member is provided wit . a refining projection at one end of the part cylindrical bearing surface, this retaining projection, in use, extending over an end of a groove provu ;d in the lev:r and eccentric arrangement to axially retain a cylindrical force tr; asmiiting member which is arranged in said groove.
Further, the two bearing seat members are each pref rably located in said further recesses so as to be freely rotatable therein aboi t an uxis perpendicular to the base of each recess. Thus, on assembl the bearing seat members can be loosely located in said further recesses wit! the bearing seat members being automatically correctly aligned with each ot er as and when the lever and eccentric arrangement is located thereon. Attentively, the bearing seat members may be of suitable design eg. tapered base re ;ions, to locate in
suitably designed further recesses in the brake housing reces: , with initial operation of the brake applying pressure to each bearing seal men her via the lever and eccentric arrangement, and causing deformation ol the base regions and/or further recesses, to thus provide for a secure positive locat: on of the bearing seat members in the brake housing, correctly aligne Further, by manufacturing the bearing seat members its separate components from the brake housing, a more suitable mater i<. for the beaj.ing seat members can be selected without need to make vhole brake housing of same material. thus cost construction minimized any reduction in performance characteristics.> According to a further aspect of the present invention theri is provided a disc brake comprising a brake housing which straddles a I raking disc and is slidably mounted on a torque taking member which carries directly actuated and an indirectly actuated friction pad assembly located on uppos.te side faces of the braking disc, the brake housing being slidable to ware ; and away from the braking disc under the action of an actuator mechanism vliich is housed in' part of the brake housing on one side of the braking disc, t \c actiator mechanism comprising a pair of tappets which can engage ;, gainst the directly actuatable friction pad assembly, said tappets being axially :lidable towards the braking disc by a lever and eccentric arrangement, one end region of the lever having two lateral extensions, each extension forming a pai . cylindrical bearing surface which is supported on a bearing seat within the bra :e noising, a groove extending transversely of the lever between the said later il projections,
said groove being eccentric relative to said part cylindrical b :arinj; surfaces and housing a force transmitting member towards each end i ijgion thereol', each force transmitting member engaging a respective tappei an intermedate member located in the groove between said two force transn litting members serving to correctly position said force transmitting member; with respect, to the tappers and carrying a gear drive which engages with an adjuster mechanism which can operate to adjust the length of the tap lets as necessary.
Preferably the groove is of part cylindrical configura ion with the force transmission members being cylindrical members, the intemediats member being likewise cylindrical with the gear drive projecting laterally from the outer surface thereof. The groove may be semi-circular in t ansv* rse cro ;s section or less than a semi-circle in transverse cross section in which case the force transmitting members and the intermediate member a i merely be located laterally within the groove during installation. Alte natively, if the groove is larger than a semi-circle, the various members ha ;e to be axially slid into the groove.
Whilst the force transmitting members are rotatable vithii the groove and are axially retained in position preferably by the intern sdiatc member and the retaining projection of each bearing seat member as de; ;ribed hereabove, the intermediate member is preferably fixed in the groove gainst rotation and/or axial movement by the surface of the lever adjacent the groove teing staked ie. deformed, at spaced locations along the axial lei jth o: the grsove. Alternatively, the intermediate member may be axially reti ined n the groove,
eg. by the force transmitting members, though rotatable then in to a limited extent, the rotational limit being defined by the gear drive ei paging the sides of the groove, this limited rotation possibly providing for th The lever and lateral extensions are preferably cast w ,th the groov; required to locate the force transmitting members and interai ;diate member, being machined in one operation. Whilst the lever and later 1 extensions are preferably manufactured from cast steel, the intermediate mriiber could, if desired, be manufactured from any other suitable metal, eg. >;ven a plastics type of material.
The above construction provides an improved weight reduced lever and eccentric arrangement which is easy to manufacture and am iged to advantageously provide a drive mechanism to the adjuster n: xhariism.
According to a still further aspect of the present inve ution there is provided a disc brake comprising a torque taking member uliich straddles a braking disc, with a brake housing being slidably mounted ad assembly

being likewise carried by the torque taking member on the c >posiie side of the braking disc, a seal assembly in the form of an annular cons ruction beini; secured between the brake housing, the head of the tappet and a siaft of the tappet, the annular seal assembly comprising a flexible annu ar boot member, one end region of which is secured in a groove in the head i igior of the tappet, the other end region being located between a surface of thj brake housing adjacent to the bearing aperture and part of a gener.il cylindrical retaining section which is engaged securely within an enlarged di The above still further aspect of the present inventio . provides a double tappet seal which is positively secured to the brake housing ;md which is relatively easy i:o instal. In a preferred construction of the eal assembly the annular lip seal is secured eg bonded, coaxially with the an .ular retaining member which is preferably made of metal. The combined lip seal and retaining member are, during construction of the brake, fitted intD an enlarged end region of me bearing aperture, prior to the tappet beinj inse:ted in the bearing aperture. The retaining member being an interfere ;ce fi; in the enlarged end region of the bearing aperture. Then the tapj ;t wiih the flexible boot member secured to the head region of the tappet, is h jertec; through the lip seal and thus the bearing aperture, the flexible boot me: iber lien be .ng secured between the retaining member and an adjacent surl ice o: the brike
housing.
In an alternative embodiment wherein the flexible bo >t member is also secured to the retaining member so that the boot member, li'.' seal and retaining member form a unitary construction, the flexible b :tot member is secured to the head region of the tappet with the lip seal loc i.ted en the tappet shaft, prior to installation of the tappet in the bearing apertu :e. On insertion of the tappet into the bearing aperture the retaining member >:an he pressed into the enlarged end region of the bearing aperture as an i;iterfe:-ence fit, securing the lip seal in the desired position relative to the ta :pet shaft wall as well as retaining the flexible boot in the desired position,
The above individual aspects of the construction of ti le present invention improve the performance characteristics and ease nf maiufacture and can be adopted in combination with each other or individual iy as desired
Accordingly, the present invention relates to a disc brake comprising a brake housing which, in use, straddles a braking disc and is slidably mounted on a torque taking member, so as to be movable towards and away from the braking disc, the brake housing incorporating a brake actuator mechanism located on one side of the braking disc and arranged to directly engage a friction pad assembly carried by the torque taking member on one side of the braking disc, another friction pad assembly being likewise carried by the torque taking member on the other side of the braking disc, the brake actuator mechanism comprising at least one adjustable tappet assembly which can be engaged with the directly actuated friction pad assembly under the action of a lever and eccentric arrangement, the actuator assembly being located within a recess in the brake housing which recess is open towards the braking disc, and closed by a cover plate secured to the brake housing, characterised in that the tappet extends through a bearing aperture in the cover plate, which bearing aperture is formed by an inside wall of a bearing projection integrally formed with the cover plate, the bearing projection extending into the said recess of the brake housing over a major portion of the length of said tappet.

The present invention will now be further described, by way of example, with reference to the accompanying drawings, in 'i'hich -
Fig. 1 is a partially cut-away view of one embodime lit of a disc brake constructed according to the present invention;
Fig. 1A is a cross sectional view of the brake showr in F:g. 1;
Fig. IB is a cross-sectional view of part of a modifi :d embodiment .of the present invention;
Fig. 2 is a partially cut-away view of a further emb Fig. 3 i;> a partially cat-away view of a still further embodiment of a
disc brake constructed according to the present invention;
Fig. 4 is a cross sectional view of part of a still furtf ;Jr modified embodiment of the present invention;
Fig. 5 is a cross sectional view taken along line A-A in Fig. 4;
Fig. 6 is a view of the brake with the cover plate rei \oved, illustrating the mirror image duplication of available recesses;
Fig. 7 is a perspective, partially cut-away view of a :earkg seat member according to a further aspect of the present inventic :i;
Fig. S is an inverted plan view of the bearing seat m :;mber of Fig. 7;
Fig. 9 is a rear view of a lever arrangement as utilis Fig. 10 is a front view of the lever in Fig. 9;
Fig. 11 is a side view of the lever of Figs. 9 and 10
Fig 12 is a plan view of the intermediate member u ed with the 'ever of Figs. 9 to 11;
Fig. 13 is an end view of the intermediate member Fig. 14 is a cutaway partial view of any one of the * Tibociments of Figs 1 to 3, illustrating the seal assembly of the present inv ntion, in enlarged detail.
Referring to the embodiment of me present inventioi illustrated in Figs. 1 and 1A of the accompanying drawings, the brake basicall corr prises i. brake housing generally designated 1, which straddles a braking disc 3 and is slidably mounted on a torque taking member 5 by virtue of guide p: is (not illustrated)
in a conventional manner.
The brake housing 1 comprises a main body section i' whiih is be died to a bridge section 9. Alternatively, the main body section .nd the bridge section can be integrally cast as a unitary construction, the riain body section having a cavity or recess 11 within which a brake actuator i lechanism generally designated 13 is located, the cavity or recess in th1 brai.e housing being open towards the braking disc 3 to allow for the locat on 01 the actuator mechanism 13 during manufacture and assembly.
The actuator mechanism 13 comprises a pair of tappt assemblies 15, 17 which are psjallel to each other and which extend throuj i bearing apurtures 19, 21 provided in a cover plate 23 which is secured to the brake housing 1 and which closes off the said cavity/recess 11, each tappet 'ress this friction pad assembly 25 against one side of the braking disc 3. Cc itinund pressure causes the brake housing 1 to slide on the guide pins relativ; to tie torque taking member 5 and braking disc 3, with the bridge sectio . 9 pressing on an indirectly actuatable friction pad assembly 29 which engage the opposite side of the braking disc 3.
Each tappet assembly 15, 17 comprises an elongate emah part 31 which has an enlarged head region 33 which can engage or act upon the
directly actuatable friction pad assembly 25. The other end i-egioi 35 of said female part 31 has a blind bore 37 which extends axially thi mgh the said female part 31. Threadedly interengaged in said blind bore '. 1 is n male part 39 of each tappet assembly 15, 17, the outer end region of s lid rr ale part 39 being formed with an enlarged head region 41 on which the lever and eccentric arrangement 27 acts.
As evident in Fig. 1 of the accompanying drawings t le co/er plate 23 is provided with a cylindrical extension 43 projecting perpei'iicularly therefrom and into the cavity 11 of the brake housing 1, the innei wall of this cylindrical extension 43 forming a supporting bearing surfac ; for the Outur wall of the female part 31 of each tappet assembly 15, 17, t te cy indrica; extension 43 supporting said female part 31 for the majority of its length and thus limiting, if not preventing, tilting of the female part 31 of thi tapper assembly 15,17 in its bearing support.
Further, the enlarged head region 41 of the male par 39 cf each tappet assembly 15,17 has a cylindrical lip extension 45 which ext removal or miiLmising of tapered wear on the friction pad a itsemblies 25, 29, and improving brake and adjuster efficiency.
As seen in Fig. 1 of the accompanying drawings, tht ferns le part 31 of each tappet assembly 15, 17 is keyed as at 47 for solely axi .1 movement within the cylindrical projection 43 of the cover plate 23, rotation i if the male part 39 of each tappet assembly 15,17 thus solely causing axial movJinen: of the female part 31 thereof.
Further, the cylindrical lip 45 carries an annular was ter 4!) against which one end of a coiled spring 51 engages, the other end .ingaging the cover plate 23. This spring 51 thus presses the male part 39 of ez ;h tappet assembly 15, 17 against the lever and eccentric arrangement 27.
To produce axial adjustment of each tappet assembly 15, ] 7 rotation of the male part 39 is required and this is effected via teeth 53 provided on the outer surface of the cylindrical lip 45, a gear wheel 55 of a,' adjuster mechanism 57 engaging the teeth 53 on the respective male Darts 39 of tie respective tappet assemblies 15, 17.
The adjuster mechanism 57 is likewise carried in a r cess 59 defried by a cylindrical projection 61 of the cover plate 23, this cylind ical iupport 61 positively retaining and securing the position of the adjuster mechanism ;>7 within the brake housing 1, and thereby ensuring improved positioning with respect to the male part 39.
Additionally, further recessed projections (see Fig. ( I can be provided ie. cast in the cover plate 23, to facilitate positive retention md jositioning of
various mechanisms eg. a pad wear sensor mechanism. Preierably, such recessed projections are provided in a mirror image duplicaiton (see ghosted circles 44,46 in Fig. 4) so that during assembly of the braki the cover plate 23 will readily fit all of the desired features whichever way .it is located. The adjuster mechanism 57 comprises the gear whee 55 which is fixedly mounted on core part 63 which is freely rotatably m;>untei on rotatable shaft 65, a further cylindrical core part 67 being fixed on si id shaft 65 against rotation relative thereto, with a wrap spring 69 engaging th wrap spring 69 which provides a lower drag torque between the core pans 63, 67 in the reverse direction of rotation.
In a modified form of the disc brake constructed ac& irding to the present invention and shown in Fig. IB, wherein the referer >:e numerals used in Fig. 1 are again used to indicate equivalent parts, the freet 15,17 engages, the inside wall of said free end region 43' thus supporting the male part of the tappet. This enlarged head region 41 is providec with the teeth 53 which mesh with the adjuster mechanism via an opening 43' in tie wall of the said free end region, the spring 51 being likewise within the cylirdrical projection between the enlarged head region 41 and a shouh ar fo -med by the stepped bore in the cylindrical projection 43.
In a further modified form of the disc brake of the p esent invention as shown in Fig. 2 of the accompanying drawings, wherein tte refetence numerals used in Fig. 1 are again used to indicate equivaler. part;, the said cylindrical extensions 43 of the cover plate 23 are reduced i i axie 1 length as compared to those of the Fig. 1 construction, with a bearins cylindrical liner 75 being secured therein and extending for the major part o the length of the female part 31 of each tappet assembly 15,17, the cylindric; I lip 4-5 of the male pan 39 of each tappet assembly 15, 17 engaging over he fr;e end region of the respective bearing liners 75. By this construction, th bearing liner 75 can be made of a more suitable, usually more expensive be; ring :naterial as

opposed to the usual cast material construction of the cover date 13, thereby minimising the cost of construction.
In a still further embodiment of the present tnventior as illustrated in Fig. 3 of the accompanying drawings, wherein the referenci numerals used in Fig. 1 are again used to indicate equivalent pans, whilst the cylindrical extensions 43 of the cover plate 23 are as provided in the ei ibodiment ol' Fig. 1, the cylindrical lip 45 on the enlarged head region 41 of : :& male part 39 of the respective tappet assemblies 15, 17, is formed by an ariMilar membet 77 which is secured around the enlarged head region 41 of eac:. mali; part 39, this annular member 77 forming the required cylindrical lip whi :h engages over the cylindrical extension 43 of the cover plate 23 to support the male part 3S' of each tappet assembly 15,17, the outer surface of each annul ir member 77 being provided with appropriate teeth 79 which mesh with Hie geir wheel 55 of the adjuster mechanism 57. This modified construction »:an piovide advantages in manufacture particularly with the choice of miterials bearing in mind wear etc. with regard to the meshing of the teeth 79 A 1th the gear wheel ' 55 of the adjuster mechanism 57.
Whilst the male and female parts 31, 39 in each of i le embodiments of Figs. 1, 2 and 3 of the accompanying drawings are keyed t igeuVr by an axially extending spline/groove (see 47 in Fig. 1), Figs. 4 ind 5 of the accompanying drawings show a modified form of the prese it invention wherein the female part 31 of each tappet assembly 15, 17 .s keyed for solely axial movement within the bearing projection 43 of the CON isr pU.te 23, by the
outer profile of die transverse cross section of the female pa : 31 being trilobal and being located in a complimentary trilobal transverse cro! s seciion bearing aperture 43' in the bearing projection 43 of the cover plate . 3. Tbus the female part 31 is an axially slidable fit on the bearing apertu re 43 but cannot be rotated relative thereto, rotation of the axially secure mal: pan 39 thereby causing axial movement of the female part in the bearing ap :rture 43'.
Further the trilobal cross sections of the two tappet a range unents 15, 17 are arranged in the same orientation with the apex 43" of 01 ie lobe of each trilobal cross section being directed towards the centre of ro ition of the brake disc 3 as shown in Fig.4 of the accompanying drawings. B; this construction the tendency for the tappets 15, 17 to bind and/or tilt in the ^earhg apertures 43', as the brake experiences torque during brake applications, is minimised.
This trilobal construction is considered easier to man facto re than, for example, a spliued arrangement such as shown at 47 in Fig. 1, as it can be formed by a simple forging process on said female part 31. Also if the bearing aperture 43' is formed by a bearing sleeve 75' secursd to the cover plate 23, as shown in Figs. 4 and 5, the trilobal construction is easily foimed with the sleeve 75' being manufactured by way of sintering md therefore: requiring a minimum amount of finishing. If desired, the s itereil bearing 75' may be cast into the die cast cover plate 23.
With regard to the lever and eccentric arrangement 1 1 in each of the embodiments of Figs. 1, 2 and 3 of the accompanying draw .ngs us best seen in Figs. 9 to 13, this comprises an elongate lever 81, one upr. :r eni region 83 of
the lever 81 being engageable by actuating means such as a ineumatic actuator, whilst the other, lower end region 85 has two opp Eccentric to the centre of curvature of the respective mrved bearing surfaces 89 of the operational bearing shaft, and generally o iposile to said bearing surfaces is an elongate groove 95 which is machine( alon; the length of said operational bearing shaft. This groove 95 has a pail cylindrical configuration which is less than semi-circular in transverse
located at opposite end regions of the groove 95 with an int rmediate member 99 located therebetween, the intermediate member 99 preve .ting ixial movement of the force transmitting members 97 towards ea h Other. Ths gear drive 7? previously referred to is a lateral extension of this intermediate member 99 and the intermediate member 99 is secured agai ist rotation or axial movement in the groove 95 by adjacent regions of the open .tiona, bearing shaft being deformed ie. staked, adjacent to the edge of the groo e 95. Alternatively, the intermediate member 99 may be allowed o route to a
limited degree, rotation being limited by the lateral gear dri e 73 engaging the edges of the groove 95, this limited rotation providing for tl ie required lost motion in the adjuster mechanism 57 to which the gear driv : 73 is meshed.
Whilst the intermediate member 99 is made of cast s eel it may alternatively, if desired, be made of any suitable other meta lie material or even a plastics material.
As referred to hereabove the curved bearing surfaces 89 ai opposite end regions of the operational bearing shaft are supported on be >rings 91 which are mounted on complimentarily curved surfaces 101 in bearing seat members 93 which are themselves located in appropriate recesses 109 in the bDttom face of the cavity 11 in the brake housing 1, These bearing seat m mibers 93 ara best illustrated in Figs. 7 and 8 wherein it will be seen that eact bearing seat member 93 presents a curved bearing support surface 101, it one end of which is provided a retaining section 105. As evident from Figs. L, 2 und 3, these retaining sections 105 extend over the ends of the groove 9 in the operational bearing shaft to hold the force transmitting members 97 in he respective end regions of the said groove 95.
As shown in Fig.8 the base 107 of each bearing sea member 93 is generally of circular/cylindrical configuration and is freely 'otatably located in a complimentary recess 109 in the base of the cavity 11. T tus, curing installation, when the bearing operational shaft and bearing 91 are located on the respective bearing seat members 93, the bearing seat m '-mbe:'S 93 rotate in their respective recesses 109 to become accurately and con toy aligned with
each other for subsequent use.
In a modified form of construction, the base of each bearing seat member 93 is shaped eg, tapered, so as to overly the edges >f the recesses 109 hi the base of the cavity 11 hi the brake housing 1. Thus, > 'hilst the respective bearing seat members 93 can be generally located in positio: , wh;n the bver and eccentric arrangement 27 is located on the respective be aring seat members 93, the bearing seat members 93 rotate to correctly and acci irately align with each other, and then on initial use of the brake, the bearing seat members 93 are deformed into the respective recesses 109 to firmly and wsiti/ely secure the bearing seat members 93 as an integral part of the brake housing 1. Alternative possible shapes and configurations are of course possible for the bearing seat members 93 and the recesses 109 to provide to this positive and secure attachment of the bearing seat members 93 to the Ice housing 1.
Further these bearing seat members 93 facilitate mai ifacture as ii would be difficult to machine appropriate bearing support s irfaces 101 iii the base region of the cavity 11 in the brake housing 1 without the p'ovisior. of an ' outer cover plate, or a lateral opening which would then require :o be sealed. Also, by the provision of separate components as bearing a at members ?3, a more suitable material can be selected for the construction of the bearing seat members 93 without the need for the whole brake housing i to be manufactured from the selected material. Thus manufactur og costs can be reduced in two different ways by virtue of the provision of the separate bearing seat members 93.
Further, as evident from Figs. 1, 2 and 14 of the ace ompaiying drawings, a positive and secure seal assembly 110 is provide ii for each tappet assembly 15, 19. Each such seal assembly 110 comprises a.: annular flexible boot 111, one end 113 of which is beaded and resiliency an ]. finely engaged in an annular recess 115 around the head region of the fema le pait 31 of the tappet assembly 15,17. The other end region of the flexible boot 111 is likewise beaded 117 and engages between an upper surface >f the cover plate 23 and a parallel surface of an annular retaining member 11 :i which is of stepped configuration in transverse cross section. A furthe lip seal 119 is secured eg. bonded, to the inner edge of the retaining meml er 118 so as to project inwardly thereof. A middle region of this retaining member 118 is generally cylindrical and engages in an enlarged diameter r With the above sealing assembly 110 construction, assembly is facilitated and manufacturing costs thereby reduced, the an ular :ip seal 119 is secured eg bonded, coaxially with the annular retaining me aber 118 which is preferably made of metal. During construction of the brak :, the combined lip seal 119 and retaining member 118 are fitted into the enlar ed end region 121 of the bearing aperture 19, prior to the tappet 15,17 being in the bearing aperture 19, the retaining member 118 being an in ; e fit in the enlarged end region 121 of the bearing aperture 19. Then Lhe teppet 15,17
with the flexible boot member 111 secured to the head regie i 33 ->f the famale part 31 of the tappet 15,17, is inserted through the lip seal J19 aid thus ihe bearing aperture 19, the flexible boot member 111 then beir i» secured between the retaining member 118 and an adjacent surface of the co^ ir plJite 23,
ID an alo;nnative embodiment (not illustrated) the fie; ible l»oot member 111 is also secured eg bonded, to the retaining member 118 so that the boot member 111, lip seal 119 and retaining member US form a unitary construction, the sealing assembly 110 can be attached to th:; female part 31 of a tappet 15,17 assembly with the bead 113 being securely e tgaged in the annular recess 115 in the head region 33 of the said female part :•!, after the retaining member 118 and sealing lip 119 have been slid a dally along trie outer surface of the said female part 31. Then, the female i art 3.. of the tappet assembly 15,17 can be inserted into the bearing aperture 1:p together with the seal assembly 110, and the cylindrical portion of the retain.' The above construction of disc brake has consideralie pe .formarce advantages together with advantages respect of the ease of isseir bly ie. reduce manufacturing costs.

We Claim:
1. A disc brake comprising a brake housing (1) which, in use, straddles a
braking disc (3) and is slidably mounted on a torque taking member
(5), so as to be movable towards and away from the braking disc (3),
the brake housing (1) incorporating a brake actuator mechanism (13)
located on one side of the braking disc (3) and arranged to directly
engage a friction pad assembly (25) carried by the torque taking
member (5) on one side of the braking disc (3), another friction pad
assembly (29) being likewise carried by the torque taking member (5)
on the other side of the braking disc (3), the brake actuator
mechanism (13) comprising at least one adjustable tappet assembly
(15; 17) which can be engaged with the directly actuated friction pad
assembly (25) under the action of a lever and eccentric arrangement
(27), the actuator assembly (13) being located within a recess (11 ] in
the brake housing (1), which recess (11) is open towards the braking
disc (3), and closed by a cover plate (23) secured to the brake housing
(1), characterised in that the tappet (15; 17) extends through a
bearing aperture (19; 21) in the cover plate (23), which bearing
aperture (19; 21) is formed by an inside wall (143) of a bearing
projection (43) integrally formed with the cover plate (23), the bearing
projection extending into the said recess of the brake housing (1) over
a major portion of the length of said tappet (15; 17).
2. A disc brake as claimed in claim 1, whefe»jsaid at least one tappet
assembly (15; 17) comprises an elongate female part (31) having an

axially extending blind bore (32) into which an elongate male part (39) is threadedly engaged.
3. A disc brake as claimed in claim 2, wherein the said elongate female
part (31) has an enlarged diameter head (33) at one end region
thereof, this enlarged diameter head (33) engaging, in use, the directly
actuated friction pad assembly (25), the elongate male part (39)
likewise having an enlarged head (41) which is, in use, engaged and
acted upon by the said eccentric arrangement (27).
4. A disc brake as claimed in claim 3, wherein the said enlarged head of
the said male part (41) forms a bearing surface which engages a wall
of the axially extending projection (43) integrally formed with the cover
plate (23) .
5. A disc brake as claimed in claim 4, wherein the said enlarged head
(41) of the said male part (39) has an axially extending lip (45) at its
outer edge region, which lip extends towards the threaded end region
(41) of the male part (39) and forms a cylindrical inner bearing surface
(89) which engages around an outer cylindrical wall region of said
axially extending projection (43) integrally formed with the cover plate
(23).
6. A disc brake as claimed in claim 5, wherein the said axially extending
lip (45) and the enlarged head (41) of the male part (39) are of unitary
construction.
7. A disc brake as claimed in claim 5, wherein the said axially extending
lip (45) is formed by a hollow cylindrical member secured to the outer
surface of the enlarged head region (41) of the male part (39).
8. A disc brake as claimed in claim 4, wherein the said free end region of
said projection (43) has an enlarged internal diameter section which
engages around an outer peripheral bearing surface provided in the
enlarged head (41) of said male part (39).
9. A disc brake as claimed in any of the preceding claims , wherein the
said projection (43) integrally formed with the cover plate (23) is
formed by a bearing sleeve secured to the cover plate.
10. A disc brake as claimed in claim 9, wherein the said bearing sleeve
(43) is constructed of a different material from the cover plate (23 ).
11. A disc brake as claimed in claim 10, wherein the said bearing sleeve
(43) is made of a sintered bearing material and is cast into the cover
plate (23) which is itself die cast.
12. A disc brake as claimed in any of claims 1 to 8 , wherein the said
projection (43) and said cover plate (23) are of unitary construction. ,
13. A disc brake as claimed in any of the preceding claims, wherein the
said bearing aperture (143) in the said projection (43), has a non-
circular transverse cross section into which the said female part (31)
with a complimentary outer profile transverse cross section, engages.
14. A disc brake as claimed in claim 13, wherein the said bearing
aperture (143) in the said projection (43), has a trilobal transverse
cross section and the said female part (31) has a complimentary
trilobal outer profile transverse cross section.
15. A disc brake as claimed in any of claims 1 to, 13, wherein there are
two tappet assemblies (15; 17) between which an adjuster mechanism
(57) is located.
16. A disc brake as claimed in claim 15, wherein the said adjuster
mechanism (57) incorporates a gear wheel (55) which meshes with
teeth (53) provided on respective head regions of the respective male
parts (39) of said tappet assemblies (15; 17), whereby rotation of the
gear wheel (55) causes rotation of the male parts (39) and resultant
axial movement of said female parts (31) of said tappet assemblies
(15; 17).
17. A disc brake as claimed in claim 16, wherein the said adjuster
mechanism (57) is operable by gear teeth (63) provided on the lever
and eccentric arrangement (27), which gear teeth engage with said
gear wheel (55) with a lost motion mechanism being incorporated to
thus only allow said gear wheel (55) to rotate to adjust the tappet
assemblies (15; 17) when the lever has been moved through a
distance.
18. A disc brake as claimed in any of claims 15 to 17, wherein the said
adjuster mechanism (57) is secured in position on the cover plate (23),
in a further bearing projection (61) integrally formed with the cover
plate (23).
19. A disc brake substantially as herein described with reference to and
illustrated in the accompanying drawings.

Documents:

2241-del-1998-abstract.pdf

2241-del-1998-assignments.pdf

2241-del-1998-claims.pdf

2241-del-1998-correspondence-others.pdf

2241-del-1998-correspondence-po.pdf

2241-del-1998-description (complete).pdf

2241-del-1998-drawings.pdf

2241-del-1998-form-1.pdf

2241-del-1998-form-13.pdf

2241-del-1998-form-19.pdf

2241-del-1998-form-2.pdf

2241-del-1998-form-3.pdf

2241-del-1998-form-4.pdf

2241-del-1998-form-6.pdf

2241-del-1998-gpa.pdf

2241-del-1998-pct-210.pdf

2241-del-1998-petition-138.pdf

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Patent Number

214395

Indian Patent Application Number

2241/DEL/1998

PG Journal Number

08/2008

Publication Date

22-Feb-2008

Grant Date

11-Feb-2008

Date of Filing

31-Jul-1998

Name of Patentee

MERITOR AUTOMOTIVE, INC.,

Applicant Address

2135 MAPLE ROAD, TROY, MICHIGAN 48084, USA

Inventors:

#	Inventor's Name	Inventor's Address
1	CARL EDWARD HEINLEIN	ST. DAVIDS, CHEPSTOW ROAD, LANGSTONE, GWENT, NP6 2JR, WALES, ENGLAND.
2	PHILIP LEONARD TROTT	12 QUEEN STREET, NP6 2JR, BLAENAVON, GWENT, ENGLAND.
3	JONATHAN LESLIE CHRISTOPHER JACKSON	27 GRANGE PARK, WHITCHURCH, MONMOUTH, GWENT, WALES, ENGLAND.

PCT International Classification Number

F16D 65/56

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	9716363.8	1997-08-02	U.K.