Reinforced Bottom Bag

Abstract

A bag, usually made of plastic sheet material is provided with a substantially rectangular panel hinged to the inner surface of the bag and foldable from flat parallel relation to the opposed bag walls to a position at right angles to the walls and forming the bag bottom.

Description

This invention relates to an improvement in reinforced bottom bag and deals particularly with a bag made of readily flexible material, and preferably of plastic sheeting, although it may be made of paper.

BACKGROUND OF THE INVENTION

Shopping bags have been produced in great quantities for many years. These bags are usually provided with handles of one type or another by means of which the bags may be carried, and are made for the most part of paper having sufficient strength to support relatively heavy articles. Paper shopping bags are usually made on bag forming machines which form the completed bag from a web of paper. In general, paper shopping bags, when opened, provide a flat bottom which holds the bag in its expanded form.

In recent years the use of plastic films in the formation of shopping bags has been increasingly popular. These bags, usually formed of polyethylene or some other polyolefin films may be naturally colorful and attractive, and may be made to support substantial weight. However, a film of this type normally does not lend itself for production on bag machines of conventional form. Normally, the bottom of the bag will not maintain a rectangular shape when the bag is opened, and the bag tends to conform to the shape of the goods being carried. As a result, when the partially filled bag is placed upon a supporting surface, it may or may not stand up. This is particularly true when the bag is used to support relatively thin packages or small cylindrical objects, as the bag flexes into virtually a flat form.

SUMMARY OF THE INVENTION

I have found that an improved bag may be formed by attaching a generally rectangular panel of corrugated paperboard or similar material to a wall of the bag so that when the bag is in its flat form, the panel will remain flat between the side walls of the bag. However, when the bag is opened, the reinforcing panel may be folded down into horizontal form, flexing the walls of the bag into generally rectangular relation and holding the walls in such a relation. This panel is capable of materially strengthening the bag by distributing the weight of the contents over the entire bottom of the bag.

An added feature of the present invention resides in the provision of a reinforced bag of the type described in which the reinforcing panel may compensate for any minor fault in the seam at the bottom of the bag. Plastic bags of the type in question may comprise a double web of material sealed together along opposite side edges, or may even comprise a tube of plastic sheeting transversely sealed at the bottom end. The use of the reinforcing panel tends to prevent the weight of the contents from bursting a seam of the bag if the seal is not effective.

A feature of the present invention resides in the provision of a reinforcing panel which may be secured to a wall of the bag before the web or tube is sealed thus simplifying the attachment of the reinforcing panel. In a bag which is of the bottom gusset type, the reinforcing panel may be attached to the inner surface of the web of the material prior to the time the web is folded and sealed, thus simplifying the automatic production of the bag including the reinforcing panel.

Another feature of the present invention resides in the provision of a reinforcing panel which may be either attached by a strip of flexible type such as pressure sensitive tape, or which may comprise a panel having a hinged flange along one edge, which flange is adhered to the bag wall. In either event, the reinforcing panel may fold from parallel relation to the side walls of the bag to a position at right angles thereto to rest upon the bag bottom and to act as a support for the bag contents.

These and other objects and novel features of the present invention will be more clearly and fully set forth in the following specification and claims .

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an open bag, a portion of the bag being broken away to disclose the reinforcing panel.

FIG. 2 is a plan view of the flattened bag showing the gusset bottom and reinforcing panel in dotted lines.

FIG. 3 is a diagrammatic view of the bag blank before the walls of the bag have been folded and sealed.

FIG. 4 is a sectional view through the flat folded bag, the position of the section being indicated by the line 4--4 of FIG. 2.

FIG. 5 is a sectional view through a portion of the open bag, the position of the section being indicated by the line 5--5 of FIG. 1.

FIG. 6 is a plan view of a modified form of supporting panel.

FIG. 7 is a view similar to FIG. 4, but showing the modified form of reinforcing panel in place.

FIG. 8 is a view similar to FIG. 5 showing the modified form of reinforcing panel in use.

FIG. 9 is a plan view of a flattened bag of somewhat different form.

FIG. 10 is a perspective view of the bag illustrated in FIG. 9 in open position.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The bag may be of various forms, and is shown in the drawings for the purpose if illustration as having a gusseted bottom portion and flat side walls. The bag A may be formed of the blank illustrated in FIG. 3 of the drawings. This blank includes a pair of side wall panels 10 and 11 which are connected by a pair of similar gusset panels 12 and 13 which are centrally connected together at 14, and which are foldably connected to the walls 10 and 11 respectively by the lines of fold 15 and 16. In the event the bag is made of paper, these fold lines are actually creases. However, when made of plastic, the sheet may be merely folded along the lines.

A reinforcing panel 17 is foldably connected to the gusset panel 12 by a strip 19 of pressure sensitive tape or other readily foldable material. The tape strip 19 partially overlies the reinforcing sheet 17, the edge of which extends along, and is parallel to, the fold line 15. The tape strip 19 could also be doubled and placed between the reinforcing panel 17 and the side wall 10. The purpose of the strip is merely to support the edge of the reinforcing panel closely adjoining the fold line 15. The panel 17 is made of paperboard or any suitable material which is rigid relative to the bag material.

In the particular type of bag illustrated, the gusset panels 12 and 13 are folded into face contact overlying the panel 10 and a portion of the reinforcing panel 17. The side wall panel 11 is folded into superimposed relation with the similar side wall panel 10. The side edges of the side panels 10 and 11, as well as the gusset panels 12 and 13 are then sealed together to form the gusset bottom bag. When folded, the bag appears as indicated in FIG. 2 with the side edges 20 heat sealed or otherwise secured together and with the gusset panels folded between the lower portions of the side walls. The arrangement of parts is shown in section in greatly enlarged form in FIG. 4 of the drawings, the reinforcing panel 17 being folded between the gusset panel 12 and the side wall 10, and the tape strip 19 being doubled.

When the bag A is opened up, the reinforcing panel 17 is folded downwardly in the manner indicated by the arrow 21, holding the bottom of the bag in generally rectangular form. As will be seen, the reinforcing panel 17 is equal in width (parallel to the side edges of the bag) to the combined width of the gusset panels 12 and 13 in a direction at right angles to the various lines of fold. The length of the reinforcing pad in a direction indicated by the dimension W is substantially equal to the width of the side walls 10 and 11 when the bag is squared up. In other words, the length W is equal approximately to the width of the front and rear walls 10 and 11 less the combined width of the gusset panels 12 and 13. As indicated, the reinforcing panel 17 is secured midway between the side edges of the panel 10 so that when swung down into the position indicated in FIG. 5 of the drawings, the reinforcing panel is substantially equal to the cross-section of the erected bag.

FIG. 6 of the drawings indicates a modified form of reinforcing panel which may be substituted for the panel 17. The reinforcing panel 23 is of substantially the same size and dimensions as the panel 17, but is hingedly connected along a fold line 24 to an anchoring flange 25. In this arrangement, the reinforcing panel 23 is secured in the same manner as the panel 17, with the fold line 24 substantially corresponding to the fold line 15 shown in FIG. 3. Adhesive of some type, or a heat sealable film, is applied to the flange 15. When the bag B is folded as indicated in FIG. 7 of the drawings, the reinforcing panel 23 lies against the bag wall 10, and the flange 25 is folded through 180 degrees and secured to the adjoining gusset panel 12 substantially as indicated. As is shown in FIG. 8 of the drawings, the reinforcing panel 23 serves exactly the same purpose as the reinforcing panel 17, the only difference being that the anchoring flange 25 is substituted for the tape strip 19 used in the bag. With this exception, the two bags, A and B are of identical form.

The bag C illustrated in FIGS. 9 and 10 of the drawings is merely a different type of bag in which the triangular folds 26 which are formed by the erection of the bag project outwardly from the walls rather than inwardly thereof. The bag C is, in effect, merely a tube of plastic sheeting or other similar material which is sealed along the lower edge 29, and which may be either sealed along the side edges 30 or may be merely a tube. In other words, the bottom gusset panels shown in the bags of FIGS. 1 through 8 are merely eliminated in the bag C, and the bag comprises merely front and rear wall panels 30 and 31 which are connected along three edges.

In this arrangement, the reinforcing panel 32 is connected within the bag body along a fold line 33 which is spaced from the sealed lower edge 29 of the bag a distance equal to one half the thickness of the erected bag. Stated otherwise, the reinforcing panel 32 is shaped to substantially fill the cross sectional area of the bag when opened to its maximum form illustrated in FIG. 10 of the drawings. When swung from the flat condition illustrated in FIG. 9 to the position indicated in FIG. 10, the bottom of the bag is squared up and is held in generally flat form.

Plastic bags of the type in question are usually provided with some sort of carrying handles. The side walls 30 and 31 are provided with generally D-shaped plastic rings 34 which are sealed to a surface of the bag and the material of the side walls is cut away within the ring-shaped handles to permit the insertion of the hand. Similar handles, or handles or other form, may be attached to the bags A and B to simplify the carrying operation. In view of the fact that the handles are well known in the art, they are shown only for the purpose of illustration.

In accordance with the patent statues, I have described the principles of construction and operation of my reinforced bottom bag; and while I have endeavored to show the best embodiments thereof, I desire to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention.

Claims

I claim:

1. A bag including a flexible tubular body, the tubular body having a pair of generally rectangular wall panels foldably connected along opposite edges, a pair of rectangular bottom panels foldably connected together along adjoining edges and foldably connected to the lower edges of said rectangular wall panels, a rectangular reinforcing panel, said reinforcing panel having an outer periphery substantially equal to the inner periphery of said tubular body, said reinforcing panel having a width substantially equal to the combined widths of said bottom panels, means securing an edge of said reinforcing panel to one of said bottom panels and lying in face contact with the rectangular wall panel to which said one bottom panel is foldably connected when said bag is in flat form, said reinforcing panel being folded to overlie said securing means in face contact therewith when said wall panels are folded into rectangular open position and holding said wall panels in substantially right angular relation to said bottom panels and holding side portions of said wall panels in right angular relation to the intermediate portions of said side wall panels.

2. The structure of claim 1, and in which said reinforcing panel is formed of paperboard.

3. The structure of claim 1, and in which said means hingedly connecting said panel comprises a flexible tape.

4. The structure of claim 1, and in which said means hingedly connecting said panel comprises a flange hingedly connected to said panel and secured to said body.