US 3318444 A
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United States Patent O 3,318,444 PAD F INDIVIDUALLY DETACHABLE BAGS Sdney Weicher, 20 Elk Ave., and Albert Einbinder, 3 Bon Air Ave., both of New Rochelle, N.Y. 10804 Filed June 10, 1964, Ser. No. 374,136 5 Claims. (Cl. 206 57) Our present invention relates to a pad of stacked bags, especially plastic ones, which are individually detachable for ready use.
In the manufacture of plastic bags, particularly those made from heat-sealable plastic material such as polyethylene, it is often desirable to produce bags that are initially closed at both ends and are subsequently cut open. The initial closure seals the interior of the bag against contamination, yet the need for a separate cutting operation just before use represents `a distinct disadvantage from the customer's Viewpoint.
It is, therefore, an object of our invention to provide a pad of stacked bags which, upon their individual separation from the stack, detach themselves from an edge strip so as to exhibit an open end even though they had been originally closed on all sides.
A more particular object of our invention is to provide a pad of this type having means for insuring that each bag detaches itself with a clean break along a predetermined line of separation.
In order to realize the aforestated objects, in conformity with this invention, we stack the generally rectangular and, usually, coextensive bags in such manner that their edges are aligned on at least one side of the stack, advantageously at the top if the pad comprising the stack is to be hung on a wall or other support for ready detachment of each bag by a downward pull. At a location close to the side of the aligned edges, thus normally close to its upper edge, each bag is provided with a weakened zone which extends completely across its width and which may be formed by a row of perforations, by scoring or in some other known manner, depending on the material used to make the bag. A header, of a material considerably stiffer than the flexible bag material, overlies the aligned edges and extends beyond the aforesaid weakened zone to serve as a guide for the motion of the outermost bag in the process of separating it from the remainder of the stack; at a location between the aligned edges and the weakened zone, the bags are fastened to one another and to the header so that an edge strip will remain attached to the header after the bag has been removed.
In accordance with a further feature of this invention we have found that, particularly with bags of relatively yieldable sheet material such as polyethylene, the fastening means should be confined to a region near the center of the weakened zone in order to concentrate the separating stress in that region for facilitating the initial rupture of that zone. This region however, must not be so narrow as to give rise to a rupture transverse to the edge of the sheet, as might be the case if the fastener were a single rivet or clasp penetrating the bag at one point; we prefer, therefore, to use as the fastener a single staple disposed parallel and close to the weakened zone, i e., horizontally in the case of an upright bag.
The invention will be described hereinafter in greater detail with reference to the accompanying drawing whose sole figure is a perspective view (parts broken away) of a pad embodying the features set forth above.
The pad shown in the drawing comprises a multiplicity of upright bags 1, of identical rectangular shape, so stacked as to have aligned upper and lower edges 2, 3 along which each bag is initially sealed during manufacture. Thus, as is well known per se, these bags may have been produced from a fiattened tubular sheet of heatsealable plastic material, such as polyethylene, by thermally sealing the tube at locations spaced apart by the length of an individual bag and seven'ng the bags from one another by cutting across the tube within the region of the thermal seal or welding the tube transversely in such manner that the bag separate at the welds. At the same time, or in a separate operation, each bag is formed with a row of throughgoing perforations 4 which define a weakened transverse zone just below the upper edge 2. A header 5 of relatively stiff material, such as wood, metal, cardboard or hard plastic, is folded about the aligned upper edges 2 of the stacked bags 1 so as to form a pair of aprons 6, 6' which overlie the perforated zone 4 and extend for a substantial distance therebeyond while also covering the stack over its entire width, thereby positively guiding the exposed front bag in a downward direction when the user grips it along its lower edge 3 to separate it from the remaining bags. A staple 8, disposed horizontally substantially at the center of the strip which is bounded by the perforated zone 4 and the upper edge 2 of each bag, fastens the bag 1 onto the header 5; the latter is formed with a hole 7 to accommodate a hook 9 from which the pad 10 may be suspended.
The strip portions of the bag engaged by the staple S remain permanently in position within the header 5 and, together with the aprons 6 and 6', help prevent the formation of dogs ears at the upper corners of the bag. Also, since the bags remain closely packed in the region of their perforations 4, their interior is protected against the entrance of dust and dirt through these perforations or even through the open ends of the bags if the top edges were left unsealed.
The extent of the apron 6 below the perforated zone 4 is not critical, yet it will be convenient to position the stape 8 approximately midway along the height of the header 5. Also, while it will be advantageous in many cases to have this header terminate fiush with the vertical sides of the stack, this is not -absolutely necessary; in fact, the header may well extend for a considerable distance beyond either side of the stack, e.g. where it is desired to attach several stacks alongside one another to a common header.
It will be apparent that, upon the exertion of a downward pull on one of the bags 1, this bag will begin to separate from its edge strip at the center of the line of perforations 4 and will form a clean break along that line which henceforth becomes the open end of the detached bag.
1. A pad comprising a stack of generally coextensive rectangular bags of flexible heat-sealable plastic material withaligned edges on at least one side, each bag having a closed bottom remote from said one side, having a closed top forming said one side, and being provided with a weakened zone extending completely across it close to said one side and substantially parallel to said aligned edges; a header of a relatively stiff material overlying said aligned edges and extending beyond said zone, said header being folded about said aligned edges on one of the minor sides of said stack and forming a pair of aligned aprons extending completely across the stack and terminating substantially ilush with the major sides thereof while extending from said aligned edges beyond said weakened zone, the major sides of the bags of the stack being closed; and fastening means joining said header to said bags at a location between said closed top and said zone.
2. A pad as defined in claim 1 wherein said weakened References Cited by the Examiner zone is constituted by a line of pe'forations. V UNITED STATES PATENTS 3. A pad as defined in claim 1 wherein said fastening 1 101 107 6/1914 Tschopk 206 57 means engages said bags along a line parallel and close 1197822 9/1916 Harbeck 229 33 to said zone, said line being confined to a small fracton 5 1,353,954 9/1920 Henry 206 57 of the bag width at the center of said zone. 1,354,810 10/1920 Erickson 206 57 4. A pad as defined in claim 1 wherein said fastening 1,873,610 3/1932 Lyonmeans comprises a single horizontal staple disposed close 2,997,167 8/1961 Westfan 206 57 to said zone at the center thereof. 3,126,094 3 /1964 Arnold et al 206 57 5. A pad as defined in claim 1 wherein said plastic ma- 10V terial is polyethylene. LOUIS G. MANCENE, Primary Examiner.