US 3633642 A
Two opposed bag walls are sealed together at the side edges and at the bottom. Two fastener elements are respectively integral with said bag walls and disposed on the inside thereof and spaced from the free end thereof. The fastener consists of two interengaging hollow ribs, which have outside wall portions that do not contact each other and constitute webs for backing the interengaging other wall portions of the hollow ribs. The interengaging other wall portions consist of one-sided undercut hooks. The fastener elements have the same profile.
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Description (OCR text may contain errors)
United States Patent 11113,633,642
[ Inventor Klrlhelnz m 3,054,434 9/1962 Ausnit 150/3 Bitk nst Schwnig via Numbers, 3,173,184 3/1965 Ausnit 150 3 x Germany 3,198,228 8/1965 Naito 150/3 E 1969 Primary ExaminerDonald F. Norton [451 Patented Jan. 1 l, 1972 ArtorneyFle1t, Glpple & Jacobson  Priority Nov. 8, 1968  Germany AB R d  G 68 06 8'7 ST ACT. Two opposed bag walls are seale together at  BAG OF PLASTICS MATERIAL SHEETING 4 Claims, 4 Drawing Figs.
 US. Cl. 150/3 [51 Int. Cl B65d 33/24  Field of Search 150/3  References Cited UNITED STATES PATENTS 2,144,755 1/1939 Freedman r l l l i I 1 the side edges and at the bottom. Two fastener elements are respectively integral with said bag walls and disposed on the inside thereof and spaced from the free end thereof. The fastener consists of two interengaging hollow ribs, which have outside wall portions that do not contact each other and constitute webs for backing the interengaging other wall portions of the hollow ribs. The interengaging other wall portions consist of one-sided undercut hooks. The fastener elements have the same profile PATENIEB JAN] 1 m2 I I I I I f KARLHEINZ SIEGEL INVENTOR ATTORNEYS BAG F PLASTICS MATERIAL SHEETING This invention relates to a bag which is made of plastics material sheeting and which comprises two opposed bag walls, which are sealed together at the side edges and at the bottom, and two fastener elements, which are respectively inside thereof and spaced from the free end thereof.
A one-piece bag of plastics material is known which is intended for packaging purposes and provided with a fastener consisting of profiled ribs. In that known bag, the profiled ribs are disposed opposite to each other in the interior of the bag and are caused to interengage when it is desired to close the bag. The profiled fastener rib provided on one bag wall has an enlarged outer edge portion and the other fastener rib has a groove which is complementary to said enlarged edge portion. The enlarged outer edge portion has the cross-sectional shape of an unsymmetrical arrow, which has an outwardly directed lateral projection that is shorter and/or less inclined toward the associated bag wall than the other lateral projection, which faces the bottom of the bag, and the sidewalls of the groove have the form of inwardly directed hooks having undercut hook surfaces which correspond in their length and inclination to the length and inclination of the projections of the arrows (printed German application No. 1,278,930). Such bag of plastics material can be opened from the outside by a smaller force than from the inside. It has been found that such bags can be opened inadvertently when they are subjected to bending and flexing actions. Another disadvantage of that known bag of plastics material resides in that it is difficult to close the fastener becausethe bag walls have outwardly curved reinforcements at the base of the unsymmetrical arrow and of the groove so that a tilting effect is produced when the flat bag is placed on a support.
It is also known to provide a flexible packaging means of plastics material, which means consists ofa tube section made of thermoplastics material and formed with transverse heatsealed seams and is provided on the inside with two longitudinally extending, profiled ribs, which can be hooked one onto the other under pressure. One of said profiled ribs consists ofa one-sided hook, which is directed toward the interior of the bag. The other profiled rib consists of two webs, which are normal to the inside surface of the packaging means and disposed on both sides of the hook of the opposite profiled rib. That one of said webs which is disposed on the outside of the closure is arranged to back the rear surface of the hook. The web disposed on the inside of the closure consists .of a onesided hook. This fastener can even more easily be openedinadvertently.
it is an object of the invention to provide a bag which consists of plastics material and is provided with a fastener and designed in view of the psychology of the user. The user tends to be sceptical to a fastener which can easily be opened from the outside because he fears that such fastener will present an insufficient resistance to a force which acts from the interior of the bag. Hence, it is an object to provide a bag which is of the kind defined first hereinbefore and provided with a fastener which presents the same resistance to a force acting from the outside in the opening sense as to such force acting from the inside and the elements of which are so firmly connected that they cannot be opened inadvertently.
To accomplish that object, the invention provides a bag of the kind defined first hereinbefore in which the fastener consists of two-interengaging hollow ribs, which have outside wall portions that do not contact each other and constitute webs for backing the interengaging other wall portions ofthe hollow ribs, which interengaging other wall portions consist of one sided undercut hooks, and in which the fastener elements have the same profile.
To facilitate a desired opening of of the bag provided with a fastener, it is also proposed according to the invention to provide the fastener with tear tabs, which are thicker than the bag wall. The relatively thick tear tabs result in a lever action, which lifts the outer backing web from the hook engaged thereby so that the fastener can be relatively easily opened. Because this lever action is not produced by unintended forces acting from the inside or outside in an opening sense, the hooks will be retained in this case by the backing webs so that the fastener cannot be opened inadvertently.
in a further embodiment of the invention, the fastener has rear surfaces which are flat and parallel to each other. This design solves a problem which, by experience, has always resulted in difficulties when the known fasteners were to be closed. The known fastener profiles result in a tilting action due to the thin web to which they are attached. This tilting action may be directed to one side orto either side and appears undesirable to the user when he actuates the fastener. As pressure must be applied to the profiles in any case when they are to be closed and a large number of average users do not try to close fasteners of that kind by wiping along the same from the end, this action always involves difficulties. As the fastener according to the invention has flat and parallel rear surfaces, these difficulties are avoided because the fingertips do not contact a thin, relatively sharp elevation during the closing ac tion but bear on smooth rear surfaces on both sides. This action does not involve a feeling of a tilting or tottering action, such as was often encountered with the known profiles.
In a particularly desirable embodiment of the invention, the bag consists of a tube, the smaller one of the tube sections which are separated by the fastener is cut off and a top slider is carried by the fastener. Such bag provided with a slideroperated fastener can be manufactured at a lower cost than a fastener made from flat sheeting. On the other hand, the slider is positively guided by the fastener according to the invention because the flat and parallel rear surfaces of said fastener prevent a tilting of the slider. Such bag can be manufactured at low cost because the smaller tube section otherwise forming tear tabs can easily be cut off during the manufacturing process.
The invention will be described more fully and by way of example hereinafter with reference to the drawings, in which:
FIG. 1 is a fragmentary sectional view showing the top portion ofa bag according to the invention,
FlG. 2 is a similar view showing the bag during the opening of the fastener,
FIG. 3 is a similar view showing a fastener according to the invention provided with a top slider, and
FIG. 4'shows the device for severing the the tear tabs.
The .bag is made from a seamless tubing 1 of plastics material sheeting. The halves 2, 3 of a fastener have been made integrally with the tubing 1 during the extruding and/or blow molding thereof. The bag walls 4, 5 are sealed together at the side edges and at the bottom.
The fastener consists of two-interengaging hollow ribs 6, 7. Those outside wall portions 8, 9 of the hollow ribs which do not contact each other consist of backing webs. The interengaging other wall portion 10, 11 of the hollow ribs consist of one-sided, undercut hooks. As is readily apparent from FlG. 1, the parts 2, 3 ofthe fastener have the same profile.
The fastener 2,- 3 has rear surfaces 12, 13 which are flat and parallel. On that side which faces away from the bag, the fastener is provided with tear tabs 14, 15, which are thicker tan the bag walls 4, 5.
The fastener presents a particularly reliable resistance to forces which could inadvertently open the fastener, whether such forces act on the fastener from the inside or from the outside. This is'due to thefact that any force which is acting will force the web 9 or the web 8 even more firmly against the rear face ofthehook 10 or 11 which is backed by such web, a slight tilting action being effective within the fastener so that the fulcrum 16 or 17 becomes effective.
It is shown in FIG. 2 that when it is desired to open the fastener the relatively thick tear tabs are gripped between two fingers near the fastener so that a lever action is produced in the direction of the arrows 18 and 19. The lever action of the tear tab l5 forces the backing web 9 to move in the direction of arrow 20 so that is ceases to back the hook 10. The lever action of the tear tab 14 disengages the hook 10 from the 11 because the hook It) performs a pivotal movement which is similar to that of the web 9 and the rounded profile of its rear face enables it to slide easily past the web 9.
FIG. 3 shows a bag which is similar to that which has been explained with reference to FIGS. 1 arid 2. The special feature of this embodiment resides in that a top slider 21 straddles the fastener. It is thus apparent that the bag according to the invention may be provided with a pressure-operated fastener or with a slider-operated fastener.
FIG. 4 shows the device by which the smaller tube section 22 defined by the fastener 2, 3 is cut off to enable a mounting of the top slider. The device consists ofa pressure roller 23 of steel and of a hardened and knurled or milled cutter disc 24.
What is claimed is:
1. A bag which is made of plastics material sheeting and which comprises two opposed bag walls sealed together at the side edges and bottom thereof and two fastener elements respectively integral with said bag walls disposed on the inside thereof and spaced from the free end thereof, each fastener element including the same configuration of spaced hook means and fulcrum means, each said hook means including a single hook, each said single hook locking with each other between each said fulcrum means and adjacent said fulcrum means of the opposing fastener element when the bag is closed, and said fulcrum means of at least one of the fastener elements physically pressing against said single hook of the opposing fastener element preventing opening of the bag whenever the contents of the bag push the bag walls outward.
2. A bag according to claim 1, characterized in that each fastener element has tear tabs which are thicker than said bag walls. I t
3. A bag according to claim 1 characterized in that the fastener elements have rear surfaces which are flat and parallel.
4. A bag according to claim 3, characterized in that it is made from tubing and including a top slider mounted adjacent said rear surfaces.