US3568918A

US3568918A - Shopping bag having reinforced walls

Info

Publication number: US3568918A
Application number: US796492A
Authority: US
Inventors: Karl Olof Blomqvist
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-02-09
Filing date: 1969-02-04
Publication date: 1971-03-09
Anticipated expiration: 1988-03-09
Also published as: DE1904655A1; NL6901876A; FR2001618A1; BE728095A

Abstract

A collapsible shopping bag having four sides and a square bottom when opened out from a flattened state. It is formed by two layers of flexible and heat-sealing plastics foil with an intermediate stiffening sheet of Kraft paper inserted between such layers extending continuously across the bottom and along two opposite bag sides. The bag in flattened state has two sideforming walls connected by a transverse bellows fold to form the square bottom and the mating longitudinal edges of the walls and the ends of the bellows fold are closed by heat sealing of the plastic foil layers.

Description

D United States Patent [111 3,568,918

[72] Inventor Karl 0101 Blomqvist 2,815,898 12/1957 Thompson 229/55 l-lackstavagen 7, S-184 Akersberga, 2,821,337 1/ 1958 Morgan, Jr. 229/57 Sweden 3,067,926 12/1962 Brady 229/55 [211 App]. No. 796,492 3,396,901 8/1968 McFedries, Jr.. 229/55 [22] Filed Feb. 4, 1969 3,468,470 9/1969 Sengewald 229/55X Patented Mar. 9, 1971 FOREIGN PATENTS [32] Priority Feb. 9,1968, Oct. 11, 1968 [33] Switzerland 1 1,069,268 5/1967 Great Britain 229/57 [31 1735/1968 and 13772/1968 Primary Examiner-Raphael H. Schwartz Attorney-Wenderoth, Lind & Ponaclc [54] SHOPPING BAG HAVING REINFORCED WALLS 1 Claim, 2 Drawing Figs. I [52] US. Cl 229/55, ABSTRACT: A collapsible shopping bag having four sides and 150/1-7, /12 229/54 a square bottom when opened out from a flattened state. it is [51] r 33/02 formed by two layers of flexible and heat-sealing plastics foil 365d 33/10 with an intermediate stiffening sheet of Kraft paper inserted Fleld of Search 229/55, 54, between such layers extending continuously across the bottom 57,58 53; 12 and along two opposite bagsides. The bag in flattened state has two side-forming walls connected by a transverse bellows [56] References (med fold to form the square bottom and the mating longitudinal UNITED STATES PATENTS edges of the walls and the ends of the bellows fold are closed 2,766,926 10/1956 Thompson 229/55 by heat sealing of the plastic foil layers.

ATENTED m 9197:

KARL OLOF BLOMQVIST,

Inventor By, u.)mllmym Attorneyfl 1 SHOPPING BAG HAVING REINFORCED WALLS BACKGROUND OF THE INVENTION of plastics have also come into use. Plastic bags can easily be given a strength sufficient tostand a load of about 20 kg., but it is an inconvenience that they are difficult to open from flattened state. Further, such bags are not self-supporting, and therefore one person must sometimes hold up the bag, while another person puts in the goods.

SUMMARY OF THE INVENTION According to the invention, said drawbacks are eliminated by a bag made of double layers of soft and heat-sealing plastic foils with at least one intermediate stiffening sheet of Kraft .paper or plastics extending continuously across the bottom and along two opposite sides of the bag. The double layers of plastic foils do not, per se, involve an improvement, as the desired strength can also be obtained by a single sheet if a foil material of sufficient thickness is selected; but their purpose is to enclose the stiffening sheet and hold it in place without it being necessary to secure said paper sheet by a troublesome gluing operation. As known, a Kraft paper sheet may be rather stiff but yet it maintains the property of being readily foldable, so that the flattening of the stiffened bag is not made more difficult. Another advantage is that-the bag will have a pleasant appearance in that its interior has a uniform and smooth surface.

When the flattened bag is opened and its bottom is unfolded, said stiffening sheet imparts to the bag a rigidity sufficient to make the bag self-supporting in the same way as an opened paper bag. Two or more sheets of paper may be used, but as a rule it is sufficient with one single layer of Kraft paper having weight of 60-100 g./sq.m., for instance. Preferably, the stiffening sheet covers the whole bottom and the two sides of the bag. V A

Owing to the fact that said stiffening sheet does not extend into the end walls of the bag, the bag may be flattened as readily as a conventional plastic bag. When folding the foils into the shape of a bag, the edges of the foils may in the known way be permitted to meet in the end walls of the bag outside the edges of the stiffening sheet which thus does not prevent a normal heat sealing.

The shopping bag may to advantage be of the type which -in flattened state consists of two parallel walls connected by a transverse bellows fold adapted to form the bottom, the matin g longitudinal edge of said sidewalls as well as the ends of the bellows fold being closed by heat sealing.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail with reference to the accompanying drawings, in which:

FIG. 1 shows a perspective view of a flattened shopping bag, the bottom of which is half unfolded for better clarity;

FIG. 2 shows a perspective view of the same bag in opened condition.

a sufficient rigidity to stand by DETAILED DESCRIPTION or THE PREFERRED EMBODIMENTS In producing the bag shown in FIGS. 1 and 2, two plastic foils (3 and 4 in FIG. 2,) are placed on either side of an intermediate Kraft paper sheet 5, the width of which corresponds to the length of the square bottom to be produced. The plastic foils which are wider than the paper sheet, have

edge portions

6 and 7 projecting outside the longitudinal edges 8 and 9 (FIG. 1) of the paper to form the end walls of the bag. The laminate thus obtained is folded double in forrmrzg transverse bellows fold 10 adapted to serve as bottom. The epth of said bellows fold 10 is equal to the width of each

edge portion

6 and 7, respectively.

The

mating edges

11,12 of the foils brought together by the following operation are heat sealed throughout their length so that the bellows fold is transformed into a pocket closed at both ends. Preferably the outer foil 3 is dimensioned to project slightly outside the transverse edges of the paper sheet 5 and of the inner foil-4 at the open end of the bag, and these projecting portions are folded back and cemented to the inside of the inner foil 4, as shown at 13 in FIG. 2.

. In the known way, handles may be made integral with the bag-forming foils if the latter have sufficient strength, but if the foils are made thin it may be more convenient to make handle members of a stronger plastic material and attach them to the bag by heat sealing. ln FIGS. 1 and 2, two rectangular pieces 14 of plastic foilhave been folded double and applied such that their. legs straddle the edge portions of the bag walls at the open end of the bag. One of the handle legs has been heat sealed to the outside of theouter foil 3 (at 15) and the other leg has been heat sealed to the inside of the inner foil 4.

Each, handle member l4 hasa grip opening 16 formed therein.

If the paper sheet 5 does not extend up to the handle members 14 the welds 15 can be through-going.

When the flattened bag shown in FIG. I is opened and the bottom is unfolded, the stiffening paper sheet contributes to giving the bag the square shape shown in FIG. 1, in that the

edge portions

6,7 of the soft foils 3,4 located outside the paper sheet are easily folded around the longitudinal edges 8,9 of the paper sheet while forming two end walls 17 which thus connect the two opposite stiffened sidewalls 18. At the formation of the stiffened square bottom 19 two

triangular foil portions

20,21 indicated in FIG. 1 are formed between the bottom area and each of the end walls 17. These triangular'portions 20,21 are automatically folded inwards towards each other to form a triangular pocket 22 (FIG. 2) which contributes to an increased rigidity of adjacent end wall. Thev bag thus opened has itself in the same way as an empty paper bag.

lclaim:

l. A collapsible shopping bag having four sides and a square bottom when opened out from a flattened state comprising two layers of flexible and heat sealing plastics foil, an intermediate stiffening sheet of Kraft paper inserted between said layers extending continuously only across said bottom and along two opposite bag sides, said bag in flattened state com prising two side-forming walls connected by a transverse bellows fold to form said square bottom, the mating longitudinal edges of said walls and the ends of said bellows fold being closed by heat sealing of said plastic foil layers.

Claims

1. A collapsible shopping bag having four sides and a square bottom when opened out from a flattened state comprising two layers of flexible and heat sealing plastics foil, an intermediate stiffening sheet of Kraft paper inserted between said layers extending continuously only across said bottom and along two opposite bag sides, said bag in flattened state comprising two side-forming walls connected by a transverse bellows fold to form said square bottom, the mating longitudinal edges of said walls and the ends of said bellows fold being closed by heat sealing of said plastic foil layers.