Title of Invention	A COLLAPSED BAG AND METHOD FOR OPENING THE SAME.
Abstract	A collapsed bag(40) of unitary construction is made of supple polyment material, having first and second opposed contiguous flat sidewalls (46,47)joined at edges and at the bottom but free or with user-releasable weakening at upper edges. The upper edges define a bag mouth. Approprialely situated graspable points (42,44) at or near bag edges allow the sidewalls (46,47)to be tensioned or shapped in opposing directions (43,45)thereby causing the interlayer ching, to which supple polymene bags are renownedly susceptible, to be readily disrupted for the full distance of contact between the tensioning points and thus for virtually the entirely of the bag mouth to be opened."

Title of Invention

A COLLAPSED BAG AND METHOD FOR OPENING THE SAME.

Abstract

A collapsed bag(40) of unitary construction is made of supple polyment material, having first and second opposed contiguous flat sidewalls (46,47)joined at edges and at the bottom but free or with user-releasable weakening at upper edges. The upper edges define a bag mouth. Approprialely situated graspable points (42,44) at or near bag edges allow the sidewalls (46,47)to be tensioned or shapped in opposing directions (43,45)thereby causing the interlayer ching, to which supple polymene bags are renownedly susceptible, to be readily disrupted for the full distance of contact between the tensioning points and thus for virtually the entirely of the bag mouth to be opened."

Full Text	A COLLAPSED BAG AND METHOD FOR OPENING THE SAME Background of the Invention 1. This invention relates to the art of plastic bags, and in particular to a method of opening bags of supple polymeric material subject to interlaycr cling. The invention also relates to collapsed bags made of supple materials, such as thermoplastic films, which have, integral to their design, features which render them easy to open from the collapsed state so they can be filled with materials. The invention applies to bags of plain or side-gussetted design. 2. Description of Related Art Collapsed plastic bags as supplied empty and ready for use from stacks, rolls or various kinds of dispensers arc often difficult or tedious to open manually, partly due to being packed for a long period in a flat or compressed state and sometimes due as well to factors arising from manufacture methods, for instance "cold welding" by which cut edges tend to form a weak bond, or materials. for instance "static cling". Such problems affect most severely bags made of thin films. With thick materials, flexing two adhered layers can place tension on the layer outermost in the curve and compression on the layer innermost in the curve and, depending on thickness and elasticity and the radius of flexion, a point may be easily reached where the static force is overcome by the energy stored in the compressed and tensioned layers so that they spontaneously disengage. This process is not very reliable with thin-film bags because even with very tight curves the tension and compression differential is small on account of the difference in radius of curvature being small in turn on account of the small layer thickness, and the tension and compression generated is more easily accommodated by elasticity of the material and layers often do not disengage. Thin film bags are used routinely as checkout bags, produce bags, and general purpose bags. It is thus of advantage to design such bags to be more easily opened, in order to save time and reduce wastage of bags that are damaged during the opening attempt or discarded in frustration. Additives may sometimes help to make layers separable, but additives generally add cost and also add a further control step in the manufacturing. Furthermore, additives may have unwanted effects such as odor or allergcnicity, and some plastic additives have derived from animal fats that in some traditions and religions are strictly prohibited - for example animal-derived components even as an ingredient in food packaging materials may be unacceptable under Kosher, Halal, Hindu, or strict vegetarian standards. The public has also been sensitised to animal-derived substances used in non-traditional ways by the BSE (Bovine Spongiform Encephalopathy) problem, and also by the recent finding that some plastic additives act as hormone analogues with implications for human health and also ecological effects. Therefore not only is a solution needed to make collapsed bags easier to handle, but that solution is preferable and more consumer-acceptable if it is mechanical rather than chemical- In confirmation of the above, the number of patents for mechanical methods show that major companies recognise a strong desire for mechanical solutions to ease handling of plastic bags. CA 916383 (Walsh and Klein assigned to Leco Industries Ltd) teaches a method of selective cooling of a extruded polymeric tube for preparing blown material with thicker and thinner portions in the same sheet. Because increased thickness of material generally reduces the interlayer adhesion problem/ this can be used to make bags with thicker material near the mouth while economising on the use of material overall- An added benefit may be relatively increased strength in the area of handles. This approach to improving the opening properties of bags is now public domain and can be seen in the market, including in small bags at retail establishments like Canadian Tire. But if the objective is to have a thickened zone where the bag mouth occurs for greater ease in opening, application of the thick-thin extrusion method is restricted to bags in which the vertical bag axis is perpendicular to the direction of extrusion, for example common side-weld bags with punched handles, and not in that sense applicable to bags supplied on rolls, or T-shirt bags, or other bags whose vertical axis is parallel to the direction of extrusion. Block-headed bags, bags with tear tabs at the top, tabs in a stack of bags being block- welded together and provided with a hanger hole, are popular in many department stores- They are commonly based on the T-shirt plan but have a design feature to address ease of handling. Block-headed T-shirt bags are typically used on racks with pegs supporting the bag handles and most critically a block-welded tab of tear- off sections of a wad of bags. "These tabs are in the mouth area of each bag and attached by a weakened or partially cut zone to the main portion of the bag. When the bag is removed from the stack the tab remains behind. The principle is that the user can grasp the front of the front-most bag and tha t the force so applied will gather the front panel until a small region of that panel separates from the back layer, becomes folded and pinched by the user; then the idea is that pulling on the portion of the front panel so grasped will cause failure of the weakened portion whereby the front panel attaches to the block-welded tab and then further pulling against resistance maintained by the corresponding attachment of the back panel. This renders the bag open and supported by the rack for filling. Removal of the filled bag separates the back panel from the back panel tab, leaving the waste tab, and leaving exposed the front panel of the next bag. In practise however, while an improvement over plain T-shirt bags, reliable performance requires moist or sticky fingers, and performance is poor if the bags have to be used without racks (many situations are not compatible with racks, and sometimes supply is short and the wrong size bags are all that are available), which presumably is why many stores still do not use this type of bag. A further type of mechanical approach to easy opening of produce bags is known in the market (Sealed Air Corp. listing US 5,941,393; 5,556,019 on product; and QuikStar™ listing US 5,752,666 on product). It is analogous to a deeply gussetted bag which is then folded on its vertical axis, and which has tabs of a stack of bags block-welded and with a hanger hole. Tabs of each bag are connected by weakened zones to a part of either the front or the back panel (four tabs per bag). This concept gives a multiplicity of layers in which ease of opening benefits from the greater tension-compression differential achieved between innermost and outermost layers subjected to bending around a given radius as formed when the user pinches several layers simultaneously. Ease of opening also benefits from the improved chance of the cling between at least two adjacent layers being weak enough to be easily overcome by simple finger friction. U-S. Fat. No. 5,611,627 to Belias et al. discloses for flat bags a type having at least one main panel top edge cut on an undulating sinusoidal or sawtooth or like pattern and the other panel being either flat or similarly shaped edge but cut 180 degrees out of phase. This yields upward projections from the mouth of the bag that can be used to grasp and separate main panels and also to tie the bag closed. U.S. Pat No. 3,023,947 to McDuffie confronts problems associated with semirigid multilayer paper bags that are to be opened for filling with bulk materials and then reclosed by sewing on assembly lines. McDuffie"s solution uses gusset panels tha t are both offset and glued to mam sidewalls, reforming the bag mouth as a parallelogram and leaving the remaining gussets to form a pair of planar semirigid struts that come under compression when the bag as a whole is placed under horizontal tension in the plane of the main panels; the struts swing and expand the bag mouth, which is a parallelogram because of the glued gusset panel. In McDuffie"s solution the bag opening is limited to a width about one-half of the general cross-section of the bag. McDuffie"s approach uses not shearing as much as prying, the bag being semirigid; the pulling on McDuffie"s tabs causes the free gusset to rotate away from the adjacent main (front or rear) panel, thus prying the front and rear panels apart (vs. peeling of extra folds or shearing of main panels or portions thereof), as in Hoover or the present invention). Indeed: the ratio of the direct outward motion per unit lateral motion (pull) in McDuffie"s solution can be calculated as [sinA/(1-cosA)], where A represents the angle so formed between the free gusset and adjacent main panel. Initially this ratio is infinity (i.e. all pull and no shear)- Just after initiation, assuming an angle of 1 degree, the outward pull is over 100 times as much as the shear. The only shearing that would occur in McDuffie"s solution would be better described as a brief rubbing of some portion of the center of the main panels that remain briefly in contact due to air pressure retarding (but not preventing) the opening of the bag. A planar strut as per McDuffie is unlikely to be practicable in thin-film bags. While the reduced opening in McDuffie"s solution suffices to accommodate the ingress of granular goods or goods of relatively small dimensions, Hoover and the present invention allow full opening of the bag mouth for items up to the size of the bag volume itself. US Pat. No. 4,911,560 to Hoover et al (also filed as CA 1,329,384) addresses supple plastic bags and uses an approach that combines shearing of a part of the front and back panels and an unpeeling of extra vertical pleats which are made in the main panels of the bag and arranged in such a way as to collapse or unfold when the bag is placed under horizontal tension. If the extra pleats are located opposite each other the action is all peeling and no shear, if otherwise there is a combination. To open this type of bag requires a greater amount of movement, and a larger workspace space to accommodate it, to take up the slack provided by unfolding of the extra pleats. This solution creates at least two further problems. In many applications extra folds would be undesirable because of both complication of the printing operation and the subsequent disruption of any printed image that covers the area of the pleats. Also, this approach necessitates extra folds not otherwise required in the bag, so there is added difficulty in manufacture and indeed one source (C. Mutton of Fast Coast Converters, St. John"s) considers it impossible from his experience. The bag disclosed in JP 11349005 is locked to a central locking piece and the bag can be opened using a single hand. This bag only appears to contemplate introducing a shearing action by pulling exposed portions or directly onto the side walls. This bag relies on the provision of the central portion against which the pulling force on either one of the projecting parts is biased. Paper bags and plastic bags may have analogy by virtue of use, but not from the standpoint of practitioners of either art; techniques of manufacture in the business of cutting and gluing paper sheets are unlike those in the business of extruding thermoplastic materials. The former involves already-formed planar feedstock, laminating of multiple layers, cutting into patterned shapes that are perforated, crimped, glued, stapled, or stitched together, and requires knowledge of cutters, rollers, stitchers, and glues; whereas the latter involves pelletised feedstock that is mixed, pumped, heated, inflated, cooled, and those ordinarily skilled in the art require familiarity with melting points, extrusion of tubular material and expansion by a controlled bubble of air, frost lines, uniform or structured cooling rates. Training and qualification in the one would be a sparse recommendation for employment in the other. Most strikingly, even despite citing McDuffie, Hoover et al did not contemplate the use of offset main panels as an alternative to the additional pleats, and neither is there any evidence that McDuffie"s solution influenced any practice in the art of thermoplastic resin bags. In the case of Hoover et al, this implies either that McDuffie did not present itself as a solution, or that Hoover and proprietors chose to patent an inferior solution and rely on McDuffie"s solution not being realised by others. The number of patents addressing mechanical approaches to rendering supple bags easy to open is evidence of a long-felt need and the prospect of commercial returns from solutions to the problem. No convenient solution has so far been found, as is evidenced by the frustration many shoppers feel in the local supermarket. Summary of the Invention Accordingly, the present invention provides a collapsed bag of unitary construction made of supple polymeric material, comprising first and second opposed contiguous flat sidewalls with joined lateral edges defining left and right sides of the bag and subject to interlayer cling; a bag mouth defined by upper edges of said sidewalls; said sidewalls being configured so that each has an exposed graspable sidewall portion, at least where proximate to said bag mouth, to permit that sidewall to be grasped independently of the other sidewall at said exposed graspable sidewall portion, the exposed graspable sidewall portions of said respective opposed sidewalls being located on laterally opposite edges of said bag, said exposed graspable sidewall portions thereby being diagonally opposed, and said sidewalls being joined such that they are laterally displaceable relative to each other, whereby a clinging tendency of the contiguous sidewalls to each other can be overcome by tensioning the exposed graspable portions against each other and laterally displacing relative to each other said sidewalls over substantially the full width between said exposed graspable portions to introduce a shearing action between said contiguous sidewalls. The invention further provides a collapsed bag of unitary construction made of supple polymeric material subject to interlayer cling, comprising first and second opposed contiguous flat sidewalls with joined lateral edges defining left and right sides of the bag; a bag mouth defined by upper edges of said sidewalls; said sidewalls being configured so that each has an exposed graspable sidewall portion, at least where proximate to said bag mouth, the exposed graspable sidewall portions of said respective opposed sidewalls being located on laterally opposite edges of said bag, said exposed graspable sidewall portions thereby being diagonally opposed, whereby a clinging tendency of the contiguous sidewalls to each other can be overcome by tensioning the exposed graspable portions against each other and laterally displacing relative to each other said sidewalls over substantially the full width between said exposed graspable portions to introduce a shearing action between said contiguous sidewalls; a pair of opposed side gussets located between said first and second opposed contiguous sidewalls, each said gusset having first and second gusset panels hingedly joined to respective side edges of said first and second sidewalls, said gusset panels being freely displaceable and deformable relative to said sidewalls; and said sidewalls being configured such that a said diagonally opposed pair of exposed graspable sidewall portions is provided proximate to said bag mouth, and wherein said graspable sidewall portions are exposed by weakenings, voids, truncations or openings formed in or adjacent to the lateral edge of said sidewalls and their associated gusset panels. The invention further provides a method of opening a collapsed bag of unitary construction made of supple polymeric material and having first and second opposed contiguous fiat sidewalls with joined lateral edges defining left and right sides of the bag and subject to interlayer cling, and a bag mouth defined by upper edges of said sidewalls, comprising the steps of : grasping exposed graspable sidewall portions of said respective opposed sidewalls located on laterally opposite edges of said bag independently of each other at said exposed graspable sidewall portions; and laterally displacing relative to each other said sidewalls, by a movement that may be relatively small, over substantially the full width between said exposed graspable portions to introduce a shearing action between said contiguous sidewalls and thereby overcome a clinging tendency of the contiguous sidewalls to each other to open the bag by tensioning the exposed graspable sidewall portions. The bag designed with such graspable tensioning points may otherwise be of almost any ordinary form, for example gusseted or plain, finished as a T-shirt or handle bag or with a flat top, with or without rack holes, supplied on rolls or in stacks, with or without blocked tabs, and in many cases can be made with existing machinery and materials. The present invention teaches that it is possible to render bags easily opened by providing graspable points for readily and positively shearing said first and second side-walls that are loosely statically and otherwise adhered to each other, and that shearing can thus be effected over the full width between tensioning points so that interlayer cling forces are instantly disrupted and the bag is rendered readily openable. In some cases the shearing action may generate repulsive static forces that assist opening. The amount of shearing movement is very small, possibly in the order of the wall thickness. More specifically, the invention proposes forming bags in such a way as to exploit the fact that if the front and rear walls of the bag can be forced to slide laterally against each other then most of the adhesion forces which commonly impede opening will be disrupted and an opening will spontaneously appear. This method allows considerable force to be applied to seperating the front and rear panels, and is a very positive method compared to other systems. For a flat bag, this can be exploited by designing each panel oi the bag to have a void exposing a portion of the other panel which can be grasped to tension the sidewalls against each other. For a gussetted bag, one method of exploiting is to design the edge pleating systems of the bags so that graspable regions are either placed, formed or revealed at the edges which are diagonally opposite and therefore directly connecting one to the front panel and the other to the rear panel so that said sliding of panels against each other can be effortlessly or easily caused by outward tugging of the graspable regions and the bag therefore easily opened. One method is to make asymmetrical gussets with exposed and graspable regions such that the most direct connection of the exposed tabs is at one edge to the front and at the other to the rear panel. Or instead of normal gussets any number of edge folds can be used provided the most direct connection of the exposed tabs is at one edge to the front and at the other to the rear panel. Another method is to fold in or over the front panel"s gusset pleat on one side of the bag and the back panel"s gusset pleat on the other side, thus leaving exposed on one side of the bag a gusset pleat directly continuous with the front panel and on the other side one continuous with the back panel. Another method is, near the bag mouth, to remove, shrink or weaken a portion of these diagonally opposite gusset pleats. Other methods follow from this key method: for example, the asymmetry can be limited to, or fold in diagonally opposite exterior pleats in, only a part (near the desired opening region) of one external pleat, or create the asymmetry in pleats, or create a tab only near the desired opening region; and for such methods do the same on the diagonally opposite pleat, so the remaining intact pleats most directly connected one to the front and the other to the rear panel become graspable regions that may be tugged in order to shear the front and rear panels, apart. In accordance with another aspect of the invention there is provided a method of opening a collapsed bag of unitary construction made of supple polymeric material subject to interlayer cling and having first and second opposed contiguous flat sidewalls with joined lateral edges defining left and right sides of the bag, and a bag mouth defined by upper edges of said sidewalls, comprising the steps of grasping exposed graspable sidewall portions of said respective opposed sidewalls located on laterally opposite edges of said bag; and laterally displacing relative to each other said sidewalls over substantially the full width between said exposed graspable portions to introduce a shearing action between said contiguous sidewalls and thereby overcome a clinging tendency of the contiguous sidewalls to each other to open the bag- Brief Description of the Drawings The invention will now be described, by way of example only, with reference to the accompanying drawings, in which:- Figure 1is a sectional view through mouth region of generalised bag with hypothetical graspable regions, at diagonally opposite positions around the bag mouth, that allow the user to shear the sidewalls against each other to disrupt interJayer cling between them; Figure 2 is a sectional view through mouth region of generalised gusseted bag with at least two hypothetical graspable regions situated at diagonally opposed gusset pleats; Figure 3 A is a sectional view through mouth region of bag having offset gussets creating graspable regions that allow the user to shear the sidewalls against each other to disrupt interlayer ding between them; Figure 3E shows a section through mouth region of bag according to McDuffie; Figure 4 is a sectional view through mouth region of bag having in the region of the bag mouth openings or truncated portions of sidewalls and their associated gusset panels near or at edges and exposing graspable regions; Figure 5 is a sectional view through mouth region of a bag having graspable regions afforded by refolded portions of gussets; Figure 6 is a sectional view through a mouth region of a flat ungussetted bag having graspable regions afforded by openings in sidewall edges; Figure 7 is a perspective view of a bag having graspable regions afforded by offset gussets; Figure 8 is a perspective view of a bag of a bag having graspable regions afforded by refolded portions of gussets, Figure 9 is a perspective view of a bag having graspable regions afforded by openings in portions of gussets near the bag mouth; and Figure 10 is a perspective view of a plurality of mulripocketed bags, each having pockets with graspable regions afforded by overextending gussets. Detailed Description of the Preferred Embodiments It will be generally understood that certain features typical and normal in the range of features found in manufacture need not be specified as such, for example the tops of bags may be plain, or finished as T-shirt bags, and can but need not have block tabs, rack holes, etc Likewise, certain other common features are to be assumed where required by common sense, for example the bottoms of bags are sealed. Referring to the drawings, Figure 1 shows a section through mouth region of generalised bag 1 with hypothetical graspable region 2 to be tensioned in direction 3 against hypothetical graspable region 4 tensioned in direction 5, causing first sidewall 6 and second sidewall 7 to shear in opposite directions thus firstly confirming correct identification by user of mouth end of bag, secondly shearing sidewalls 6 and 7 in directions as shown by arrows 8 and 9. Shearing disrupts interlayer cling between the first and second sidewalls between the grasped points 2 and 3- This concept is applicable to gussetted bags. Figure 2 shows a section through mouth region of generalised gusseted bag 20 with hypothetical graspable region 22 to be tensioned in direction 23 against hypothetical graspable region 24 tensioned in direction 25, causing first sidewall 26 and second sidewall 27 to shear in opposite directions 28 and 29 thus firstly confirming correct identification by user of mouth end of bag, secondly disrupting interlayer cling and separating the first and second sidewalls over the entire distance between the grasped points.22 and 24. Making the hypothetical graspable regions practical, Figure 3A shows a section through mouth region of bag 40 having offset gussets rendering graspable region 42 which can be tensioned in direction 43 against graspable region 44 tensioned in direction 45, developing tension in first sidewall 46 and second sidewall 47, in opposite directions, between the grasped points 42 and 44- The thin vertical lines are to mark the positions of gusset pleat ends before and after tensioning the bag. Gusseted bag 40.1 shows the configuration after a small amount of movement in tension which has caused first sidewall 46.1 and second sidewall 47.1 to shear in opposite directions and interlayer cling to be disrupted between the grasped points 42 and 44; being a supple material it lies loose after the two layers separate. To compare this with an item in the prior art. Figure 3B shows a section through mouth region of bag according to US 3,023,947 (to McDuffie) for a multi-wall paper bag: bag 440 of stiff material and having offset gussets, of which one set of pleats 451 is glued together creating graspable region 442 which can be tensioned in direction 443 against graspable region 444 tensioned in direction 445, developing tension in first sidewall 446 and second sidewall 447, in opposite directions, between the grasped points 442 and 444- This tension results in compression on the free gussets 452, which rotate and act as planar struts pushing the semirigid sidewalls 446 and 447 apart. Bag 440-1 is in the open configuration after laterally tensioning sidewall 447 against sidewall 446 has induced compression of the planar strut and caused it to rotate and push the sidewalls 446-1 and 447.1 apart. Unlike the present invention and also unlike others discussed above, US 3,023,947 results in a limitation of mouth opening to only about half of the general cross-sectional area of the bag. It will be further seen that the action and result differ, because planar struts are an impossibility in supple materials, and that the intent of McDuffie could not translate to supple materials except in the limited sense of making graspable the tensioning points. Revealing another approach to making the hypothetical graspable regions practical. Figure 4 shows a section through mouth region of bag 60 having in the region of the bag mouth openings in or truncated portions 69.1 of gusset panels rendering graspable region 62 which can be tensioned in direction 63 against hypothetical graspable region 64 tensioned in direction 65, developing tension in first sidewall 66 and second sidewall 67, in opposite directions, between the grasped points 62 and 64. A small amount of movement in tension causes first sidewall 66 and second sidewall 67 to shear in opposite directions 68 and 69 and interlayer cling to be disrupted between the grasped points 52 and 64. Revealing yet another approach to making the hypothetical graspable regions practical, Figure 5 shows a section through mouth region of bag 80 having refolded portions 89.1 of gussets creating graspable region 82 which can be tensioned in direction 83 against hypothetical graspable region 64 tensioned in direction 85, developing tension in first sidewall 86 and second sidewall 87, in opposite directions, between the grasped points 82 and 84- A small amount of movement in tension causes first sidewall 86 and second sidewall 87 to shear in opposite directions 88 and 89 and interlayer cling to be disrupted between the grasped points 82 and 84. It will be seen by one ordinarily skilled in the art that the refolding could be inwards or outwards, or could take the form of a sub-gusset of the one pleat of a principal gusset. Making practical the hypothetical graspable regions illustrated in Figure 1, Figure 6 shows a section through mouth region of a flat ungussetted bag 100 having region 102, rendered graspably independent of sidewall 106 by opening 110 in sidewall 106, to be tensioned in direction 103 against graspable region 104, rendered graspably independent of sidewall 107 by opening 111 in sidewall 107, tensioned in direction 105, causing first sidewall 106 and second sidewall 107 to shear in opposite directions 108 and 109 respectively. Tensioning by user has results of, firstly, confirming correct identification by user of mouth end of bag, secondly shearing sidewalls and thus disrupting interlayer cling between the first and second sidewalls 106 and 107 between the grasped points 102 and 103. Further illustrating the sectional view of FIG. 3, Figure 7 shows a perspective view of bag 120 having offset gussets creating graspable region 122 which can be tensioned in direction 123 against graspable region 124 tensioned in direction 125, developing tension in upper edges of first sidewall 126 and second sidewall 127, in opposite directions, between the grasped points 122 and 124, and disrupting interlayer cling between the sidewalls under tension- Further illustrating the sectional view of Figure 5, Figure 8 shows a perspective view of bag 140 having refolded portions 149.1 of gussets creating graspable region 142 which can be tensioned in direction 143 against hypothetical gTaspable region 64 tensioned in direction 145, developing tension in first sidewall 146 and second sidewall 147, in opposite directions, between the grasped points 142 and 144- A small amount of movement in tension causes first sidewall 146 and second sidewall 147 to shear in opposite directions 148 and 149 and interlayer cling to be disrupted between the grasped points 142 and 144- It will be seen by one ordinarily skilled in the art that the refolding could be inwards or outwards, or could take the form of a sub-gusset of the one pleat of a principal gusset- Further illustrating the sectional view of FIG- 4, FIG- 9 shows a perspective view of bag 160 having openings in or truncated portions 169.1 of gusset panels creating graspnble region 162 which can be tensioned in direction 163 against hypothetical graspable region 164 tensioned in direction 165, developing tension in first sidewall 166 and second sidewall 167, in opposite directions, between the grasped points 162 and 164. A small amount of movement in tension causes first sidewall 166 and second sidewall 167 to shear in opposite directions 168 and 169 and interlayer cling to be disrupted between the grasped points 162 and 164. The principles used above are also applicable to multipocketed bags, having various numbers of pockets These bags may for example be convenient to the user of a packaged product by containing separately yet keeping related in storage a number of ingredients to be later mixed or used in a common process. Convenience in terms of filling the pockets is firstly due to the ease of opening the pockets which is accomplished by laterally tugging from a gxaspable point while the common back or second sidewall remains held in the filling process. Convenience may thus also be facilitated by provision of such bags on a roll which can be fed through a filling station and remaining attached one bag to the next while fed also through a reclosing station after filling, and can either be left attached up to the product"s retail stage or can be detached at any time before that For the example of two pockets. Figure 10 shows a perspective view of a plurality of multipocketed bags 180 having similar features in each- The upper two bags are shown in ideal opened view, the lower bag is shown closed. First sidewall 186 is segmented according to the number of side by side pockets separated by weld 188 or a number of such welds, while second sidewall 187 is common to all pockets. Overextending gussets create graspable regions 182 and 184. Graspable region 182 can be tensioned in direction 183, against the second sidewall 187 or any part of same that does not overlap with the first sidewall segment 186.1, to cause shearing of first sidewall segment 1861 and second sidewall 187, thence opening of the pocket pertaining to first sidewall segment 186.1. Or it may be tensioned against graspabJe region 184 tensioned in direction 185 thus developing tension in upper edges of first sidewall 186 (left and. right segments 186.1 and 186.2) and second sidewall 187, in opposite directions, between the grasped points 122 and 124, and disrupting interlayer cling between the sidewalls under tension. A transverse weld 189 seals the bottom of the bag. If bags are made or supplied in sequence, a cut or weakening (respectively) 190 separates one bag from the next. The foregoing is considered illustrative of the principles of the invention. Other embodiments and variations as may occur to those skilled within the art are considered to fall within the scope of the invention. I CLAIM: 1. A collapsed bag of unitary construction made of supple polymeric material subject to interlayer cling, comprising first and second opposed contiguous flat sidewalls with joined lateral edges defining left and right sides of the bag; a bag mouth defined by upper edges of said sidewalls; said sidewalls being configured so that each has an exposed graspable sidewall portion, at least where proximate to said bag mouth, the exposed graspable sidewall portions of said respective opposed sidewalls being located on laterally opposite edges of said bag, said exposed graspabie sidewall portions thereby being diagonally opposed, whereby a clinging tendency of the contiguous sidewalls to each other can be overcome by tensioning the exposed graspable portions against each other and laterally displacing relative to each other said sidewalls over substantially the full width between said exposed graspable portions to introduce a shearing action between said contiguous sidewalls; a pair of opposed side gussets located between said first and second opposed contiguous sidewalls, each said gusset having first and second gusset panels hingedly joined to respective side edges of said first and second sidewalls. said gusset panels being freely displaceable and deformable relative to said sidewalls: and said sidewalls being configured such that a said diagonally opposed pair of exposed graspable sidewall portions is provided proximate to said bag mouth, and wherein said graspable sidewall portions are exposed by weakenings, voids, truncations or openings formed in or adjacent to the lateral edge of said sidewalls and their associated gusset panels. 2. A collapsed bag of unitary construction made of supple polymeric material, comprising first and second opposed contiguous flat sidewalls with joined lateral edges defining left and right sides of the bag and subject to interlayer cling; a bag mouth defined by upper edges of said sidewalls; said sidewalls being configured so that each has an exposed graspable sidewall portion, at least where proximate to said bag mouth, to permit that sidewall to be grasped independently of the other sidewall at said exposed graspable sidewall portion, the exposed graspable sidewall portions of said respective opposed sidewalls being located on laterally opposite edges of said bag. said exposed graspable sidewall portions thereby being diagonally opposed, and said sidewalls being joined such that they are laterally displaceable relative to each other, whereby a clinging tendency of the contiguous sidewalls to each other can be overcome by tensioning the exposed graspable portions against each other and laterally displacing relative to each other said sidewalls over substantially the full width between said exposed; and further comprising a pair of opposed side gussets located between said first and second opposed contiguous sidewalls, each said gusset having first and second gusset panels hingedly joined to respective side edges of said first and second sidewalls. said gusset panels being freely displaceable and deformable relative to said sidewalls; and said sidewalls being configured such that a said diagonally opposed pair of exposed graspable sidewall portions is provided proximate to said bag mouth, wherein said graspable sidewall portions are exposed by a folding over, in either direction, or a forming into subsidiary gussets, of side edges of said sidewalls and their associated gusset panels. 3. A collapsed bag as claimed in claim 1, having proximate to said bag mouth a second diagonally opposed pair of exposed graspable sidewall portions, each of which graspable portions at each lateral edge of said bag is more or less noncoincident vertically with the graspablc portion pertaining to the first pair at the same lateral edge, and where the said second pair addresses the pair of gusset pleats not rendered graspable by the said first pair, such that proximate to said bag mouth both lateral edges of both sidewalls are independently graspable manually or mechanically, enabling either a choice as to which alternative diagonally opposed pair of exposed graspable points is addressed, or both disrupting interlayer cling and then fully expanding the bag mouth by using all four exposed graspable points. 4. A collapsed bag of unitary construction made of supple polymeric material, comprising first and second opposed contiguous flat sidewalls with joined lateral edges defining left and right sides of the bag and subject to interlayer cling; a bag mouth defined by upper edges of said sidewalls; said sidewalls being configured so that each has an exposed graspable sidewall portion, at least where proximate to said bag mouth, to permit that sidewall to be grasped independently of the other sidewall at said exposed graspable sidewall portion, the exposed graspable sidewall portions of said respective opposed sidewalls being located on laterally opposite edges of said bag, said exposed graspable sidewall portions thereby being diagonally opposed, and said sidewalls being joined such that they are laterally displaceable relative to each other, whereby a clinging tendency of the contiguous sidewalks to each other can be overcome by tensioning the exposed graspable portions against each other and laterally displacing relative to each other said sidewalls over substantially the full width between said exposed graspable portions to introduce a shearing action between said contiguous sidewalls; and further comprising a pair of opposed side gussets located between said first and second opposed contiguous sidewalls. each said gusset having first and second gusset panels hingedly joined to respective side edges of said first and second sidewalls, said gusset panels being freely displaceable and deformable relative to said sidewalls: and said sidewalls being configured such that a said diagonally opposed pair of exposed graspable sidewall portions is provided proximate to said bag mouth, wherein said bag is compartmented into a plurality of side-gusseted pockets formed side by side and of equal or differing width, and wherein the second sidewall of the bag is continuous or functions as continuous and more or less flat from one pocket to the next and forms the pocket backs, and wherein the first sidewall, considering its form from left to right, is convoluted to form for each pocket its left side gusset on the one side, its front, its opposing right side gusset, and then said first sidewall is welded or glued to the said second sidewall and remains continuous with pocket gussets and fronts in the next and subsequent pockets as for the first until at the completion of the last pocket, as at the beginning of the first pocket, the first sidewall is either welded or glued to the second sidewall if not already continuous with it. and wherein for each pocket at least one lateral edge of its front projects on one side or the other beyond the pocket back or the second sidewall. at least where proximate to the bag mouth, to leave at least one protruding portion that provides said exposed graspable portion of the pocket front which may be grasped and tensioned either against the graspable portion of any other pocket front to open them both, or against the second sidewall generally, which being continuous can be grasped and tensioned from any point that is tensionable from the first grasped point unless in a manner that also grasps the pocket front correspondingly grasped, to cause opening of the pocket of which the first sidewall portion is grasped. 5. A collapsed bag of unitary construction made of supple polymeric material, comprising: first and second opposed contiguous fiat sidewalls subject to interlayer cling, said first and second fiat sidewalls being arranged in a laterally offset relationship whereby a lateral edge of one of the sidewalls defines one side of the collapsed bag and a lateral edge of the other of the sidewalls defines the other side of the collapsed bag; an openable bag mouth defined by upper edges of said sidcwalls: and wherein on each side of the collapsed bag a folded gusset is located between the adjacent edges of said first and second opposed contiguous sidcwalls. each said gusset having first and second gusset panels mutually joined at an inner edge and joined at an outer edge to the respective adjacent lateral edges of said laterally offset first and second sidewalls, one said gusset panel thereby being wider than the other said gusset panel; wherein said laterally offset sidewalls define diagonally opposed protruding graspable sidewall portions extending along each sidewall below said bag mouth. each said exposed graspable sidewall portion having a width substantially less than the width of the narrower panel of the associated folded gusset; and wherein said sidewall portions are graspable by the user so that when a lateral pull is exerted on said graspable sidewall portions a shearing action is introduced between said first and second opposed contiguous flat sidewalls over substantially the full width between said exposed graspable sidewall portions to open the bag mouth over substantially its whole width between the lateral edges of the sidewalls. 6. A collapsed bag of unitary construction made of supple polymeric material that can create interlayer cling comprising: first and second opposed contiguous flat sidewalls each having an upper edge and a pair of lateral edges, said first and second sidewalls being joined together at their respective lateral edges to define left and right sides of the bag, and a bag mouth defined by upper edges of said sidewalls; said first sidewall having a first void or weaking of a portion at or near the lateral edge thereof on the right side of the bag and in the vicinity of the bag mouth: said second sidewall having a second void or weakening of a portion at or near the lateral edge thereof on the left side of the bag and in the vicinity of the bag mouth; said first and second voids or weakened portions exposing graspable sidewall portions in the opposing sidewall in a diagonally opposed relationship, whereby aplying a lateral tension to said exposed graspable sidewall portions introduces a shearing action between said first and second opposed contiguous fiat sidewalls to break said interlayer cling and open the bag mouth. 7. A collapsed bag as claimed in claim 6, having a pair of opposed side gussets located between said first and second opposed contiguous sidewalls. each said gusset having first and second gusset panels hingedly joined to respective side edges of said first and second sidewalls. said gusset panels being freely displaceablc and deformable relative to said sidewalls; wherein each graspable sidewall portion is narrower than the width of said pair of opposed side gussets. 8. A collapsed bag as claimed in any one of claims 1, 4 or 7, wherein a plurality of said bags are arranged in a roll for supplying individual bags one at a time. 9. A collapsed bag as claimed in claim 5. wherein said graspable sidewall portions are exposed by weakenings, voids, truncations or openings formed at or near the side edge of each said sidewall such that openings are non-coincident between sidewalls. 10. A method of opening a collapsed bag of unitary construction made of supple polymeric material, comprising first and second opposed contiguous flat sidewalls with joined lateral edges defining left and right sides of the bag, said first and second opposed contiguous flat sidewalls being subject to interlayer cling, a bag mouth defined by upper edges of said sidewalls. and a pair of opposed side gussets located between said first and second opposed contiguous sidewalls, each said gusset having first and second gusset panels hingedly joined to respective side edges of said first and second sidewalls, said gusset panels being freely displaceable and deformable relative to said sidewalls, wherein said sidewalls are laterally offset, at least where proximate to the bag mouth, to leave protruding portions that provide exposed narrow graspable sidewall portions on each sidewall below said bag mouth, the exposed graspable sidewall portions of said respective opposed sidewalls being located on laterally opposite edges of said bag and being diagonally opposed, wherein each narrow graspable sidewall portion is less than the width of said pair of opposed side gussets, the method comprising: grasping said exposed graspable sidewall portions permitting a corresponding sidewall to be grasped independently of the other sidewall at said exposed graspable sidewall portion; tensioning said exposed graspable sidewall portions to introduce a shearing action between said first and second opposed contiguous flat sidewalls over substantially the full width between said exposed graspable sidewall; and laterally displacing said sidewalks relative to each other by a movement that may be relatively small, over substantially the full width between said exposed graspable portions. 11. A method as claimed in claim 10, wherein one of said exposed graspable portions may be passively restrained to reduce the number of hands or moving parts required to open the bag. A collapsed bag (40) of unitary construction made of supple polymeric material having first and second opposed contiguous flat sidewalls (46. 47) joined at edges and at the bottom but free or with user-releasable weakening at upper edges. The upper edges define a bag mouth. Appropriately situated graspable points (42, 44) at or near bag edges allow the sidewalls (46, 47) to be tcnsioned or snapped in opposing directions (43. 45) thereby causing the interlayer cling, to which supple polymeric bags are renownedly susceptible, to be readily disrupted for the full distance of contact between the tensioning points and thus for virtually the entirety of the bag mouth to be opened.

Full Text

A COLLAPSED BAG AND METHOD FOR OPENING THE SAME
Background of the Invention
1. This invention relates to the art of plastic bags, and in particular to a method of opening bags
of supple polymeric material subject to interlaycr cling. The invention also relates to collapsed bags
made of supple materials, such as thermoplastic films, which have, integral to their design, features
which render them easy to open from the collapsed state so they can be filled with materials. The
invention applies to bags of plain or side-gussetted design.
2. Description of Related Art
Collapsed plastic bags as supplied empty and ready for use from stacks, rolls or various kinds of
dispensers arc often difficult or tedious to open manually, partly due to being packed for a long
period in a flat or compressed state and sometimes due as well to factors arising from manufacture
methods, for instance "cold welding" by which cut edges tend to form a weak bond, or materials.
for instance "static cling". Such problems affect most severely bags made of thin films. With thick
materials, flexing two adhered layers can place tension on the layer outermost in the curve and
compression on the layer innermost in the curve and, depending on thickness and elasticity and the
radius of flexion, a point may be easily reached where the static force is overcome by the energy
stored in the compressed and tensioned layers so that they spontaneously disengage. This process is
not very reliable with thin-film bags because even with very tight curves the tension and
compression differential is small on account of the difference in radius of curvature being small in
turn on account of the small layer thickness, and the tension and compression generated is
more easily accommodated by elasticity of the material and layers often do not disengage.
Thin film bags are used routinely as checkout bags, produce bags, and general purpose bags.
It is thus of advantage to design such bags to be more easily opened, in order to save time
and reduce wastage of bags that are damaged during the opening attempt or discarded in
frustration.
Additives may sometimes help to make layers separable, but additives generally add
cost and also add a further control step in the manufacturing. Furthermore, additives
may have unwanted effects such as odor or allergcnicity, and some plastic
additives have derived from animal fats that in some traditions and religions are
strictly prohibited - for example animal-derived components even as an ingredient
in food packaging materials may be unacceptable under Kosher, Halal, Hindu, or
strict vegetarian standards. The public has also been sensitised to animal-derived
substances used in non-traditional ways by the BSE (Bovine Spongiform
Encephalopathy) problem, and also by the recent finding that some plastic additives
act as hormone analogues with implications for human health and also ecological
effects. Therefore not only is a solution needed to make collapsed bags easier to
handle, but that solution is preferable and more consumer-acceptable if it is
mechanical rather than chemical-
In confirmation of the above, the number of patents for mechanical methods show
that major companies recognise a strong desire for mechanical solutions to ease
handling of plastic bags.
CA 916383 (Walsh and Klein assigned to Leco Industries Ltd) teaches a method of
selective cooling of a extruded polymeric tube for preparing blown material with
thicker and thinner portions in the same sheet. Because increased thickness of
material generally reduces the interlayer adhesion problem/ this can be used to
make bags with thicker material near the mouth while economising on the use of
material overall- An added benefit may be relatively increased strength in the area
of handles. This approach to improving the opening properties of bags is now
public domain and can be seen in the market, including in small bags at retail
establishments like Canadian Tire. But if the objective is to have a thickened zone
where the bag mouth occurs for greater ease in opening, application of the thick-thin
extrusion method is restricted to bags in which the vertical bag axis is perpendicular
to the direction of extrusion, for example common side-weld bags with punched
handles, and not in that sense applicable to bags supplied on rolls, or T-shirt bags, or
other bags whose vertical axis is parallel to the direction of extrusion.
Block-headed bags, bags with tear tabs at the top, tabs in a stack of bags being block-
welded together and provided with a hanger hole, are popular in many department
stores- They are commonly based on the T-shirt plan but have a design feature to
address ease of handling. Block-headed T-shirt bags are typically used on racks
with pegs supporting the bag handles and most critically a block-welded tab of tear-
off sections of a wad of bags. "These tabs are in the mouth area of each bag and
attached by a weakened or partially cut zone to the main portion of the bag. When
the bag is removed from the stack the tab remains behind. The principle is that the
user can grasp the front of the front-most bag and tha t the force so applied will
gather the front panel until a small region of that panel separates from the back
layer, becomes folded and pinched by the user; then the idea is that pulling on the
portion of the front panel so grasped will cause failure of the weakened portion
whereby the front panel attaches to the block-welded tab and then further pulling
against resistance maintained by the corresponding attachment of the back panel.
This renders the bag open and supported by the rack for filling. Removal of the
filled bag separates the back panel from the back panel tab, leaving the waste tab,
and leaving exposed the front panel of the next bag. In practise however, while an
improvement over plain T-shirt bags, reliable performance requires moist or sticky
fingers, and performance is poor if the bags have to be used without racks (many
situations are not compatible with racks, and sometimes supply is short and the
wrong size bags are all that are available), which presumably is why many stores
still do not use this type of bag.
A further type of mechanical approach to easy opening of produce bags is known in
the market (Sealed Air Corp. listing US 5,941,393; 5,556,019 on product; and
QuikStar™ listing US 5,752,666 on product). It is analogous to a deeply gussetted
bag which is then folded on its vertical axis, and which has tabs of a stack of bags
block-welded and with a hanger hole. Tabs of each bag are connected by weakened
zones to a part of either the front or the back panel (four tabs per bag). This concept
gives a multiplicity of layers in which ease of opening benefits from the greater
tension-compression differential achieved between innermost and outermost layers
subjected to bending around a given radius as formed when the user pinches several
layers simultaneously. Ease of opening also benefits from the improved chance of
the cling between at least two adjacent layers being weak enough to be easily
overcome by simple finger friction.
U-S. Fat. No. 5,611,627 to Belias et al. discloses for flat bags a type having at least one
main panel top edge cut on an undulating sinusoidal or sawtooth or like pattern and
the other panel being either flat or similarly shaped edge but cut 180 degrees out of
phase. This yields upward projections from the mouth of the bag that can be used to
grasp and separate main panels and also to tie the bag closed.
U.S. Pat No. 3,023,947 to McDuffie confronts problems associated with semirigid
multilayer paper bags that are to be opened for filling with bulk materials and then
reclosed by sewing on assembly lines. McDuffie"s solution uses gusset panels tha t
are both offset and glued to mam sidewalls, reforming the bag mouth as a
parallelogram and leaving the remaining gussets to form a pair of planar semirigid
struts that come under compression when the bag as a whole is placed under
horizontal tension in the plane of the main panels; the struts swing and expand the
bag mouth, which is a parallelogram because of the glued gusset panel. In
McDuffie"s solution the bag opening is limited to a width about one-half of the
general cross-section of the bag. McDuffie"s approach uses not shearing as much as
prying, the bag being semirigid; the pulling on McDuffie"s tabs causes the free
gusset to rotate away from the adjacent main (front or rear) panel, thus prying the
front and rear panels apart (vs. peeling of extra folds or shearing of main panels or
portions thereof), as in Hoover or the present invention). Indeed: the ratio of the
direct outward motion per unit lateral motion (pull) in McDuffie"s solution can be
calculated as [sinA/(1-cosA)], where A represents the angle so formed between the
free gusset and adjacent main panel. Initially this ratio is infinity (i.e. all pull and no
shear)- Just after initiation, assuming an angle of 1 degree, the outward pull is over
100 times as much as the shear. The only shearing that would occur in McDuffie"s
solution would be better described as a brief rubbing of some portion of the center of
the main panels that remain briefly in contact due to air pressure retarding (but not
preventing) the opening of the bag. A planar strut as per McDuffie is unlikely to be
practicable in thin-film bags. While the reduced opening in McDuffie"s solution
suffices to accommodate the ingress of granular goods or goods of relatively small
dimensions, Hoover and the present invention allow full opening of the bag mouth
for items up to the size of the bag volume itself.
US Pat. No. 4,911,560 to Hoover et al (also filed as CA 1,329,384) addresses supple
plastic bags and uses an approach that combines shearing of a part of the front and
back panels and an unpeeling of extra vertical pleats which are made in the main
panels of the bag and arranged in such a way as to collapse or unfold when the bag
is placed under horizontal tension. If the extra pleats are located opposite each other
the action is all peeling and no shear, if otherwise there is a combination. To open this type of bag
requires a greater amount of movement, and a larger workspace space to accommodate it, to take up
the slack provided by unfolding of the extra pleats. This solution creates at least two further
problems. In many applications extra folds would be undesirable because of both complication of
the printing operation and the subsequent disruption of any printed image that covers the area of the
pleats. Also, this approach necessitates extra folds not otherwise required in the bag, so there is
added difficulty in manufacture and indeed one source (C. Mutton of Fast Coast Converters, St.
John"s) considers it impossible from his experience.
The bag disclosed in JP 11349005 is locked to a central locking piece and the bag can be
opened using a single hand. This bag only appears to contemplate introducing a shearing action by
pulling exposed portions or directly onto the side walls. This bag relies on the provision of the
central portion against which the pulling force on either one of the projecting parts is biased.
Paper bags and plastic bags may have analogy by virtue of use, but not from the standpoint
of practitioners of either art; techniques of manufacture in the business of cutting and gluing paper
sheets are unlike those in the business of extruding thermoplastic materials. The former involves
already-formed planar feedstock, laminating of multiple layers, cutting into patterned shapes that are
perforated, crimped, glued, stapled, or stitched together, and requires knowledge of cutters, rollers,
stitchers, and glues; whereas the latter involves pelletised feedstock that is mixed, pumped, heated,
inflated, cooled, and those ordinarily skilled in the art require familiarity with melting points,
extrusion of tubular material and expansion by a controlled bubble of air, frost lines, uniform or
structured cooling rates. Training and qualification in the one would be a sparse recommendation
for employment in the other. Most strikingly, even despite citing McDuffie, Hoover et al did not
contemplate the use of offset main panels as an alternative to the additional pleats, and neither is
there any evidence that McDuffie"s solution influenced any practice in the art of thermoplastic resin
bags. In the case of Hoover et al, this implies either that McDuffie did not present itself as a
solution, or that Hoover and proprietors chose to patent an inferior solution and rely on McDuffie"s
solution not being realised by others.
The number of patents addressing mechanical approaches to rendering supple bags easy to
open is evidence of a long-felt need and the prospect of commercial returns from solutions to the
problem. No convenient solution has so far been found, as is evidenced by the frustration many
shoppers feel in the local supermarket.
Summary of the Invention
Accordingly, the present invention provides a collapsed bag of unitary construction made of
supple polymeric material, comprising first and second opposed contiguous flat sidewalls with
joined lateral edges defining left and right sides of the bag and subject to interlayer cling; a bag
mouth defined by upper edges of said sidewalls; said sidewalls being configured so that each has an
exposed graspable sidewall portion, at least where proximate to said bag mouth, to permit that
sidewall to be grasped independently of the other sidewall at said exposed graspable sidewall
portion, the exposed graspable sidewall portions of said respective opposed sidewalls being located
on laterally opposite edges of said bag, said exposed graspable sidewall portions thereby being
diagonally opposed, and said sidewalls being joined such that they are laterally displaceable relative
to each other, whereby a clinging tendency of the contiguous sidewalls to each other can be
overcome by tensioning the exposed graspable portions against each other and laterally displacing
relative to each other said sidewalls over substantially the full width between said exposed
graspable portions to introduce a shearing action between said contiguous sidewalls.
The invention further provides a collapsed bag of unitary construction made of supple
polymeric material subject to interlayer cling, comprising first and second opposed contiguous flat
sidewalls with joined lateral edges defining left and right sides of the bag; a bag mouth defined by
upper edges of said sidewalls; said sidewalls being configured so that each has an exposed
graspable sidewall portion, at least where proximate to said bag mouth, the exposed graspable
sidewall portions of said respective opposed sidewalls being located on laterally opposite edges of
said bag, said exposed graspable sidewall portions thereby being diagonally opposed, whereby a
clinging tendency of the contiguous sidewalls to each other can be overcome by tensioning the
exposed graspable portions against each other and laterally displacing relative to each other said
sidewalls over substantially the full width between said exposed graspable portions to introduce a
shearing action between said contiguous sidewalls; a pair of opposed side gussets located between
said first and second opposed contiguous sidewalls, each said gusset having first and second gusset
panels hingedly joined to respective side edges of said first and second sidewalls, said gusset panels
being freely displaceable and deformable relative to said sidewalls; and said sidewalls being
configured such that a said diagonally opposed pair of exposed graspable sidewall portions is
provided proximate to said bag mouth, and wherein said graspable sidewall portions are exposed by
weakenings, voids, truncations or openings formed in or adjacent to the lateral edge of said
sidewalls and their associated gusset panels.
The invention further provides a method of opening a collapsed bag of unitary construction
made of supple polymeric material and having first and second opposed contiguous fiat sidewalls
with joined lateral edges defining left and right sides of the bag and subject to interlayer cling, and a
bag mouth defined by upper edges of said sidewalls, comprising the steps of : grasping exposed
graspable sidewall portions of said respective opposed sidewalls located on laterally opposite edges
of said bag independently of each other at said exposed graspable sidewall portions; and laterally
displacing relative to each other said sidewalls, by a movement that may be relatively small, over
substantially the full width between said exposed graspable portions to introduce a shearing action
between said contiguous sidewalls and thereby overcome a clinging tendency of the contiguous
sidewalls to each other to open the bag by tensioning the exposed graspable sidewall portions.
The bag designed with such graspable tensioning points may otherwise be of almost any
ordinary form, for example gusseted or plain, finished as a T-shirt or handle bag or with a flat top,
with or without rack holes, supplied on rolls or in stacks, with or without blocked tabs, and in many
cases can be made with existing machinery and materials.
The present invention teaches that it is possible to render bags easily opened by providing
graspable points for readily and positively shearing said first and second side-walls that are loosely
statically and otherwise adhered to each other, and that shearing can thus be effected over the full
width between tensioning points so that interlayer cling forces are instantly disrupted and the bag is
rendered readily openable. In some cases the shearing action may generate repulsive static forces
that assist opening. The amount of shearing movement is very small, possibly in the order of the
wall thickness.
More specifically, the invention proposes forming bags in such a way as to exploit the fact
that if the front and rear walls of the bag can be forced to slide laterally against each other then most
of the adhesion forces which commonly impede opening will be disrupted and an opening will
spontaneously appear. This method allows considerable force to be applied to seperating the front
and rear panels, and is a very positive method compared to other systems.
For a flat bag, this can be exploited by designing each panel oi the bag to have a void
exposing a portion of the other panel which can be grasped to tension the sidewalls
against each other.
For a gussetted bag, one method of exploiting is to design the edge pleating systems
of the bags so that graspable regions are either placed, formed or revealed at the
edges which are diagonally opposite and therefore directly connecting one to the
front panel and the other to the rear panel so that said sliding of panels against each
other can be effortlessly or easily caused by outward tugging of the graspable
regions and the bag therefore easily opened.
One method is to make asymmetrical gussets with exposed and graspable regions
such that the most direct connection of the exposed tabs is at one edge to the front
and at the other to the rear panel. Or instead of normal gussets any number of edge
folds can be used provided the most direct connection of the exposed tabs is at one
edge to the front and at the other to the rear panel.
Another method is to fold in or over the front panel"s gusset pleat on one side of the
bag and the back panel"s gusset pleat on the other side, thus leaving exposed on one
side of the bag a gusset pleat directly continuous with the front panel and on the
other side one continuous with the back panel. Another method is, near the bag
mouth, to remove, shrink or weaken a portion of these diagonally opposite gusset
pleats.
Other methods follow from this key method: for example, the asymmetry can be
limited to, or fold in diagonally opposite exterior pleats in, only a part (near the
desired opening region) of one external pleat, or create the asymmetry in pleats, or
create a tab only near the desired opening region; and for such methods do the same
on the diagonally opposite pleat, so the remaining intact pleats most directly
connected one to the front and the other to the rear panel become graspable regions
that may be tugged in order to shear the front and rear panels, apart.
In accordance with another aspect of the invention there is provided a method of
opening a collapsed bag of unitary construction made of supple polymeric material
subject to interlayer cling and having first and second opposed contiguous flat
sidewalls with joined lateral edges defining left and right sides of the bag, and a bag
mouth defined by upper edges of said sidewalls, comprising the steps of grasping
exposed graspable sidewall portions of said respective opposed sidewalls located on
laterally opposite edges of said bag; and laterally displacing relative to each other
said sidewalls over substantially the full width between said exposed graspable
portions to introduce a shearing action between said contiguous sidewalls and
thereby overcome a clinging tendency of the contiguous sidewalls to each other to
open the bag-
Brief Description of the Drawings
The invention will now be described, by way of example only, with reference to the
accompanying drawings, in which:-
Figure 1is a sectional view through mouth region of generalised bag with
hypothetical graspable regions, at diagonally opposite positions around the bag
mouth, that allow the user to shear the sidewalls against each other to disrupt
interJayer cling between them;
Figure 2 is a sectional view through mouth region of generalised gusseted bag with
at least two hypothetical graspable regions situated at diagonally opposed gusset
pleats;
Figure 3 A is a sectional view through mouth region of bag having offset gussets
creating graspable regions that allow the user to shear the sidewalls against each
other to disrupt interlayer ding between them;
Figure 3E shows a section through mouth region of bag according to McDuffie;
Figure 4 is a sectional view through mouth region of bag having in the region of the
bag mouth openings or truncated portions of sidewalls and their associated gusset
panels near or at edges and exposing graspable regions;
Figure 5 is a sectional view through mouth region of a bag having graspable regions
afforded by refolded portions of gussets;
Figure 6 is a sectional view through a mouth region of a flat ungussetted bag having
graspable regions afforded by openings in sidewall edges;
Figure 7 is a perspective view of a bag having graspable regions afforded by offset
gussets;
Figure 8 is a perspective view of a bag of a bag having graspable regions afforded
by refolded portions of gussets,
Figure 9 is a perspective view of a bag having graspable regions afforded by
openings in portions of gussets near the bag mouth; and
Figure 10 is a perspective view of a plurality of mulripocketed bags, each having
pockets with graspable regions afforded by overextending gussets.
Detailed Description of the Preferred Embodiments
It will be generally understood that certain features typical and normal in the range
of features found in manufacture need not be specified as such, for example the tops
of bags may be plain, or finished as T-shirt bags, and can but need not have block
tabs, rack holes, etc Likewise, certain other common features are to be assumed
where required by common sense, for example the bottoms of bags are sealed.
Referring to the drawings, Figure 1 shows a section through mouth region of
generalised bag 1 with hypothetical graspable region 2 to be tensioned in direction 3
against hypothetical graspable region 4 tensioned in direction 5, causing first
sidewall 6 and second sidewall 7 to shear in opposite directions thus firstly
confirming correct identification by user of mouth end of bag, secondly shearing
sidewalls 6 and 7 in directions as shown by arrows 8 and 9. Shearing disrupts
interlayer cling between the first and second sidewalls between the grasped points 2
and 3-
This concept is applicable to gussetted bags. Figure 2 shows a section through
mouth region of generalised gusseted bag 20 with hypothetical graspable region 22
to be tensioned in direction 23 against hypothetical graspable region 24 tensioned in
direction 25, causing first sidewall 26 and second sidewall 27 to shear in opposite
directions 28 and 29 thus firstly confirming correct identification by user of mouth
end of bag, secondly disrupting interlayer cling and separating the first and second
sidewalls over the entire distance between the grasped points.22 and 24.
Making the hypothetical graspable regions practical, Figure 3A shows a section
through mouth region of bag 40 having offset gussets rendering graspable region 42
which can be tensioned in direction 43 against graspable region 44 tensioned in
direction 45, developing tension in first sidewall 46 and second sidewall 47, in
opposite directions, between the grasped points 42 and 44- The thin vertical lines
are to mark the positions of gusset pleat ends before and after tensioning the bag.
Gusseted bag 40.1 shows the configuration after a small amount of movement in
tension which has caused first sidewall 46.1 and second sidewall 47.1 to shear in
opposite directions and interlayer cling to be disrupted between the grasped points
42 and 44; being a supple material it lies loose after the two layers separate.
To compare this with an item in the prior art. Figure 3B shows a section through
mouth region of bag according to US 3,023,947 (to McDuffie) for a multi-wall paper
bag: bag 440 of stiff material and having offset gussets, of which one set of pleats
451 is glued together creating graspable region 442 which can be tensioned in
direction 443 against graspable region 444 tensioned in direction 445, developing
tension in first sidewall 446 and second sidewall 447, in opposite directions, between
the grasped points 442 and 444- This tension results in compression on the free
gussets 452, which rotate and act as planar struts pushing the semirigid sidewalls
446 and 447 apart. Bag 440-1 is in the open configuration after laterally tensioning
sidewall 447 against sidewall 446 has induced compression of the planar strut and
caused it to rotate and push the sidewalls 446-1 and 447.1 apart. Unlike the present
invention and also unlike others discussed above, US 3,023,947 results in a limitation
of mouth opening to only about half of the general cross-sectional area of the bag. It
will be further seen that the action and result differ, because planar struts are an
impossibility in supple materials, and that the intent of McDuffie could not translate
to supple materials except in the limited sense of making graspable the tensioning
points.
Revealing another approach to making the hypothetical graspable regions practical.
Figure 4 shows a section through mouth region of bag 60 having in the region of the
bag mouth openings in or truncated portions 69.1 of gusset panels rendering
graspable region 62 which can be tensioned in direction 63 against hypothetical
graspable region 64 tensioned in direction 65, developing tension in first sidewall 66
and second sidewall 67, in opposite directions, between the grasped points 62 and
64. A small amount of movement in tension causes first sidewall 66 and second
sidewall 67 to shear in opposite directions 68 and 69 and interlayer cling to be
disrupted between the grasped points 52 and 64.
Revealing yet another approach to making the hypothetical graspable regions
practical, Figure 5 shows a section through mouth region of bag 80 having refolded
portions 89.1 of gussets creating graspable region 82 which can be tensioned in
direction 83 against hypothetical graspable region 64 tensioned in direction 85,
developing tension in first sidewall 86 and second sidewall 87, in opposite
directions, between the grasped points 82 and 84- A small amount of movement in
tension causes first sidewall 86 and second sidewall 87 to shear in opposite
directions 88 and 89 and interlayer cling to be disrupted between the grasped points
82 and 84. It will be seen by one ordinarily skilled in the art that the refolding could
be inwards or outwards, or could take the form of a sub-gusset of the one pleat of a
principal gusset.
Making practical the hypothetical graspable regions illustrated in Figure 1, Figure 6
shows a section through mouth region of a flat ungussetted bag 100 having region
102, rendered graspably independent of sidewall 106 by opening 110 in sidewall 106,
to be tensioned in direction 103 against graspable region 104, rendered graspably
independent of sidewall 107 by opening 111 in sidewall 107, tensioned in direction
105, causing first sidewall 106 and second sidewall 107 to shear in opposite
directions 108 and 109 respectively. Tensioning by user has results of, firstly,
confirming correct identification by user of mouth end of bag, secondly shearing
sidewalls and thus disrupting interlayer cling between the first and second sidewalls
106 and 107 between the grasped points 102 and 103.
Further illustrating the sectional view of FIG. 3, Figure 7 shows a perspective view
of bag 120 having offset gussets creating graspable region 122 which can be
tensioned in direction 123 against graspable region 124 tensioned in direction 125,
developing tension in upper edges of first sidewall 126 and second sidewall 127, in
opposite directions, between the grasped points 122 and 124, and disrupting
interlayer cling between the sidewalls under tension-
Further illustrating the sectional view of Figure 5, Figure 8 shows a perspective view
of bag 140 having refolded portions 149.1 of gussets creating graspable region 142
which can be tensioned in direction 143 against hypothetical gTaspable region 64
tensioned in direction 145, developing tension in first sidewall 146 and second
sidewall 147, in opposite directions, between the grasped points 142 and 144- A
small amount of movement in tension causes first sidewall 146 and second sidewall
147 to shear in opposite directions 148 and 149 and interlayer cling to be disrupted
between the grasped points 142 and 144- It will be seen by one ordinarily skilled in
the art that the refolding could be inwards or outwards, or could take the form of a
sub-gusset of the one pleat of a principal gusset-
Further illustrating the sectional view of FIG- 4, FIG- 9 shows a perspective view of
bag 160 having openings in or truncated portions 169.1 of gusset panels creating
graspnble region 162 which can be tensioned in direction 163 against hypothetical
graspable region 164 tensioned in direction 165, developing tension in first sidewall
166 and second sidewall 167, in opposite directions, between the grasped points 162
and 164. A small amount of movement in tension causes first sidewall 166 and
second sidewall 167 to shear in opposite directions 168 and 169 and interlayer cling
to be disrupted between the grasped points 162 and 164.
The principles used above are also applicable to multipocketed bags, having various
numbers of pockets These bags may for example be convenient to the user of a
packaged product by containing separately yet keeping related in storage a number
of ingredients to be later mixed or used in a common process. Convenience in terms
of filling the pockets is firstly due to the ease of opening the pockets which is
accomplished by laterally tugging from a gxaspable point while the common back or
second sidewall remains held in the filling process. Convenience may thus also be
facilitated by provision of such bags on a roll which can be fed through a filling
station and remaining attached one bag to the next while fed also through a
reclosing station after filling, and can either be left attached up to the product"s retail
stage or can be detached at any time before that For the example of two pockets.
Figure 10 shows a perspective view of a plurality of multipocketed bags 180 having
similar features in each- The upper two bags are shown in ideal opened view, the
lower bag is shown closed. First sidewall 186 is segmented according to the number
of side by side pockets separated by weld 188 or a number of such welds, while
second sidewall 187 is common to all pockets. Overextending gussets create
graspable regions 182 and 184. Graspable region 182 can be tensioned in direction
183, against the second sidewall 187 or any part of same that does not overlap with
the first sidewall segment 186.1, to cause shearing of first sidewall segment 1861
and second sidewall 187, thence opening of the pocket pertaining to first sidewall
segment 186.1. Or it may be tensioned against graspabJe region 184 tensioned in
direction 185 thus developing tension in upper edges of first sidewall 186 (left and.
right segments 186.1 and 186.2) and second sidewall 187, in opposite directions,
between the grasped points 122 and 124, and disrupting interlayer cling between the
sidewalls under tension. A transverse weld 189 seals the bottom of the bag. If bags
are made or supplied in sequence, a cut or weakening (respectively) 190 separates
one bag from the next.
The foregoing is considered illustrative of the principles of the invention. Other
embodiments and variations as may occur to those skilled within the art are
considered to fall within the scope of the invention.
I CLAIM:
1. A collapsed bag of unitary construction made of supple polymeric material subject to
interlayer cling, comprising first and second opposed contiguous flat sidewalls with joined lateral
edges defining left and right sides of the bag; a bag mouth defined by upper edges of said sidewalls;
said sidewalls being configured so that each has an exposed graspable sidewall portion, at least where
proximate to said bag mouth, the exposed graspable sidewall portions of said respective opposed
sidewalls being located on laterally opposite edges of said bag, said exposed graspabie sidewall
portions thereby being diagonally opposed, whereby a clinging tendency of the contiguous sidewalls
to each other can be overcome by tensioning the exposed graspable portions against each other and
laterally displacing relative to each other said sidewalls over substantially the full width between said
exposed graspable portions to introduce a shearing action between said contiguous sidewalls; a pair
of opposed side gussets located between said first and second opposed contiguous sidewalls, each
said gusset having first and second gusset panels hingedly joined to respective side edges of said first
and second sidewalls. said gusset panels being freely displaceable and deformable relative to said
sidewalls: and said sidewalls being configured such that a said diagonally opposed pair of exposed
graspable sidewall portions is provided proximate to said bag mouth, and wherein said graspable
sidewall portions are exposed by weakenings, voids, truncations or openings formed in or adjacent to
the lateral edge of said sidewalls and their associated gusset panels.
2. A collapsed bag of unitary construction made of supple polymeric material, comprising first
and second opposed contiguous flat sidewalls with joined lateral edges defining left and right sides of
the bag and subject to interlayer cling; a bag mouth defined by upper edges of said sidewalls; said
sidewalls being configured so that each has an exposed graspable sidewall portion, at least where
proximate to said bag mouth, to permit that sidewall to be grasped independently of the other
sidewall at said exposed graspable sidewall portion, the exposed graspable sidewall portions of said
respective opposed sidewalls being located on laterally opposite edges of said bag. said exposed
graspable sidewall portions thereby being diagonally opposed, and said sidewalls being joined such
that they are laterally displaceable relative to each other, whereby a clinging tendency of the
contiguous sidewalls to each other can be overcome by tensioning the exposed graspable portions
against each other and laterally displacing relative to each other said sidewalls over substantially the
full width between said exposed; and further comprising a pair of opposed side gussets located
between said first and second opposed contiguous sidewalls, each said gusset having first and second
gusset panels hingedly joined to respective side edges of said first and second sidewalls. said gusset
panels being freely displaceable and deformable relative to said sidewalls; and said sidewalls being
configured such that a said diagonally opposed pair of exposed graspable sidewall portions is
provided proximate to said bag mouth, wherein said graspable sidewall portions are exposed by a
folding over, in either direction, or a forming into subsidiary gussets, of side edges of said sidewalls
and their associated gusset panels.
3. A collapsed bag as claimed in claim 1, having proximate to said bag mouth a second
diagonally opposed pair of exposed graspable sidewall portions, each of which graspable portions at
each lateral edge of said bag is more or less noncoincident vertically with the graspablc portion
pertaining to the first pair at the same lateral edge, and where the said second pair addresses the pair
of gusset pleats not rendered graspable by the said first pair, such that proximate to said bag mouth
both lateral edges of both sidewalls are independently graspable manually or mechanically, enabling
either a choice as to which alternative diagonally opposed pair of exposed graspable points is
addressed, or both disrupting interlayer cling and then fully expanding the bag mouth by using all
four exposed graspable points.
4. A collapsed bag of unitary construction made of supple polymeric material, comprising first
and second opposed contiguous flat sidewalls with joined lateral edges defining left and right sides of
the bag and subject to interlayer cling; a bag mouth defined by upper edges of said sidewalls; said
sidewalls being configured so that each has an exposed graspable sidewall portion, at least where
proximate to said bag mouth, to permit that sidewall to be grasped independently of the other
sidewall at said exposed graspable sidewall portion, the exposed graspable sidewall portions of said
respective opposed sidewalls being located on laterally opposite edges of said bag, said exposed
graspable sidewall portions thereby being diagonally opposed, and said sidewalls being joined such
that they are laterally displaceable relative to each other, whereby a clinging tendency of the
contiguous sidewalks to each other can be overcome by tensioning the exposed graspable portions
against each other and laterally displacing relative to each other said sidewalls over substantially the
full width between said exposed graspable portions to introduce a shearing action between said
contiguous sidewalls; and further comprising a pair of opposed side gussets located between said first
and second opposed contiguous sidewalls. each said gusset having first and second gusset panels
hingedly joined to respective side edges of said first and second sidewalls, said gusset panels being
freely displaceable and deformable relative to said sidewalls: and said sidewalls being configured
such that a said diagonally opposed pair of exposed graspable sidewall portions is provided
proximate to said bag mouth, wherein said bag is compartmented into a plurality of side-gusseted
pockets formed side by side and of equal or differing width, and wherein the second sidewall of the
bag is continuous or functions as continuous and more or less flat from one pocket to the next and
forms the pocket backs, and wherein the first sidewall, considering its form from left to right, is
convoluted to form for each pocket its left side gusset on the one side, its front, its opposing right
side gusset, and then said first sidewall is welded or glued to the said second sidewall and remains
continuous with pocket gussets and fronts in the next and subsequent pockets as for the first until at
the completion of the last pocket, as at the beginning of the first pocket, the first sidewall is either
welded or glued to the second sidewall if not already continuous with it. and wherein for each pocket
at least one lateral edge of its front projects on one side or the other beyond the pocket back or the
second sidewall. at least where proximate to the bag mouth, to leave at least one protruding portion
that provides said exposed graspable portion of the pocket front which may be grasped and tensioned
either against the graspable portion of any other pocket front to open them both, or against the second
sidewall generally, which being continuous can be grasped and tensioned from any point that is
tensionable from the first grasped point unless in a manner that also grasps the pocket front
correspondingly grasped, to cause opening of the pocket of which the first sidewall portion is
grasped.
5. A collapsed bag of unitary construction made of supple polymeric material, comprising:
first and second opposed contiguous fiat sidewalls subject to interlayer cling, said first and
second fiat sidewalls being arranged in a laterally offset relationship whereby a lateral edge of one of
the sidewalls defines one side of the collapsed bag and a lateral edge of the other of the sidewalls
defines the other side of the collapsed bag;
an openable bag mouth defined by upper edges of said sidcwalls: and
wherein on each side of the collapsed bag a folded gusset is located between the adjacent
edges of said first and second opposed contiguous sidcwalls. each said gusset having first and second
gusset panels mutually joined at an inner edge and joined at an outer edge to the respective adjacent
lateral edges of said laterally offset first and second sidewalls, one said gusset panel thereby being
wider than the other said gusset panel;
wherein said laterally offset sidewalls define diagonally opposed protruding graspable
sidewall portions extending along each sidewall below said bag mouth. each said exposed graspable
sidewall portion having a width substantially less than the width of the narrower panel of the
associated folded gusset; and
wherein said sidewall portions are graspable by the user so that when a lateral pull is exerted
on said graspable sidewall portions a shearing action is introduced between said first and second
opposed contiguous flat sidewalls over substantially the full width between said exposed graspable
sidewall portions to open the bag mouth over substantially its whole width between the lateral edges
of the sidewalls.
6. A collapsed bag of unitary construction made of supple polymeric material that can create
interlayer cling comprising:
first and second opposed contiguous flat sidewalls each having an upper edge and a pair of
lateral edges, said first and second sidewalls being joined together at their respective lateral edges to
define left and right sides of the bag, and
a bag mouth defined by upper edges of said sidewalls;
said first sidewall having a first void or weaking of a portion at or near the lateral edge thereof
on the right side of the bag and in the vicinity of the bag mouth:
said second sidewall having a second void or weakening of a portion at or near the lateral
edge thereof on the left side of the bag and in the vicinity of the bag mouth;
said first and second voids or weakened portions exposing graspable sidewall portions in the
opposing sidewall in a diagonally opposed relationship, whereby aplying a lateral tension to said
exposed graspable sidewall portions introduces a shearing action between said first and second
opposed contiguous fiat sidewalls to break said interlayer cling and open the bag mouth.
7. A collapsed bag as claimed in claim 6, having a pair of opposed side gussets located between
said first and second opposed contiguous sidewalls. each said gusset having first and second gusset
panels hingedly joined to respective side edges of said first and second sidewalls. said gusset panels
being freely displaceablc and deformable relative to said sidewalls; wherein each graspable sidewall
portion is narrower than the width of said pair of opposed side gussets.
8. A collapsed bag as claimed in any one of claims 1, 4 or 7, wherein a plurality of said bags are
arranged in a roll for supplying individual bags one at a time.
9. A collapsed bag as claimed in claim 5. wherein said graspable sidewall portions are exposed
by weakenings, voids, truncations or openings formed at or near the side edge of each said sidewall
such that openings are non-coincident between sidewalls.
10. A method of opening a collapsed bag of unitary construction made of supple polymeric
material, comprising first and second opposed contiguous flat sidewalls with joined lateral edges
defining left and right sides of the bag, said first and second opposed contiguous flat sidewalls being
subject to interlayer cling, a bag mouth defined by upper edges of said sidewalls. and a pair of
opposed side gussets located between said first and second opposed contiguous sidewalls, each said
gusset having first and second gusset panels hingedly joined to respective side edges of said first and
second sidewalls, said gusset panels being freely displaceable and deformable relative to said
sidewalls, wherein said sidewalls are laterally offset, at least where proximate to the bag mouth, to
leave protruding portions that provide exposed narrow graspable sidewall portions on each sidewall
below said bag mouth, the exposed graspable sidewall portions of said respective opposed sidewalls
being located on laterally opposite edges of said bag and being diagonally opposed, wherein each
narrow graspable sidewall portion is less than the width of said pair of opposed side gussets, the
method comprising:
grasping said exposed graspable sidewall portions permitting a corresponding sidewall to be
grasped independently of the other sidewall at said exposed graspable sidewall portion;
tensioning said exposed graspable sidewall portions to introduce a shearing action between
said first and second opposed contiguous flat sidewalls over substantially the full width between said
exposed graspable sidewall; and
laterally displacing said sidewalks relative to each other by a movement that may be relatively
small, over substantially the full width between said exposed graspable portions.
11. A method as claimed in claim 10, wherein one of said exposed graspable portions may be
passively restrained to reduce the number of hands or moving parts required to open the bag.
A collapsed bag (40) of unitary construction made of supple polymeric material having first
and second opposed contiguous flat sidewalls (46. 47) joined at edges and at the bottom but free or
with user-releasable weakening at upper edges. The upper edges define a bag mouth. Appropriately
situated graspable points (42, 44) at or near bag edges allow the sidewalls (46, 47) to be tcnsioned
or snapped in opposing directions (43. 45) thereby causing the interlayer cling, to which supple
polymeric bags are renownedly susceptible, to be readily disrupted for the full distance of contact
between the tensioning points and thus for virtually the entirety of the bag mouth to be opened.

Documents:

922-kolnp-2003-granted-abstract.pdf

922-kolnp-2003-granted-claims.pdf

922-kolnp-2003-granted-correspondence.pdf

922-kolnp-2003-granted-description (complete).pdf

922-kolnp-2003-granted-drawings.pdf

922-kolnp-2003-granted-form 1.pdf

922-kolnp-2003-granted-form 18.pdf

922-kolnp-2003-granted-form 3.pdf

922-kolnp-2003-granted-form 5.pdf

922-kolnp-2003-granted-form 6.pdf

922-kolnp-2003-granted-letter patent.pdf

922-kolnp-2003-granted-reply to examination report.pdf

922-kolnp-2003-granted-specification.pdf

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Patent Number

218583

Indian Patent Application Number

00922/KOLNP/2003

PG Journal Number

14/2008

Publication Date

04-Apr-2008

Grant Date

02-Apr-2008

Date of Filing

17-Jul-2003

Name of Patentee

BELL KIM N. I.,

Applicant Address

25 MONKSTOWN ROAD, ST JOHN'S, NEWFOUNDLAND A1C 3T2

Inventors:

#	Inventor's Name	Inventor's Address
1	BELL KIM N. I.,	25 MONKSTOWN ROAD, ST JOHN'S, NEWFOUNDLAND A1C 3T2

PCT International Classification Number

B65D 33/00

PCT International Application Number

PCT/CA01/01785

PCT International Filing date

2001-12-17

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	2000/7586	2000-12-18	South Africa