United States Patent 3589594

The invention provides a collapsible bag comprising a prismatic, tubular body having hingedly connected wall panels so as to be collapsible to flat condition, and hinged flaps at the ends of the tube to constitute the bottom and the top of the bag, all parts being kept in interlocking relationship by means of a carrying strap introduced between the top flaps and the bottom flaps.

Fischlein, Svend (Albertslund, DK)
Karpf, Peter (Borkerod, DK)
Tragaardh, Jan K. (Lyngby, DK)
Application Number:
Publication Date:
Filing Date:
Primary Class:
Other Classes:
229/117.11, 229/117.25, 229/144, 229/914, 383/25, 383/29, 383/99, D09/432
International Classes:
A45C3/00; B65D5/46; B65D5/465; (IPC1-7): B65D31/16; B65D33/06
Field of Search:
229/37,52,54,53 150
View Patent Images:
US Patent References:
3361333Carton closure and carrying device1968-01-02Stuart
3117710Container1964-01-14Beach, Jr.
3024959Collapsed containers and method of producing same1962-03-13Kuchenbecker

Foreign References:
Primary Examiner:
Bockenek, David M.
We claim

1. A foldable-flat bag comprising a cubical, tubular body including alternate pairs of side and end wall panels hingedly connected at lateral edges for forming a tubular body when erected:

2. The structure as claimed in claim 1, in which said pairs of segments are triangular and said intermediate segment is trapezoidal.

3. The structure as claimed in claim 1, wherein said strap is threaded within said bag and along the inner surface of said end walls, and said strap extending through said channels flanking the bottom closure flap and being disposed exteriorly and juxtaposed beneath said bottom closure flaps.

4. The structure as claimed in claim 1, in which the end wall panels include a slot intermediate of the upper and lower marginal edges, said strap being threaded through said slots.

5. The structure as claimed in claim 4, in which said strap extends vertically on the outer surface on said end walls.

This invention relates to collapsible bags provided with a carrying strap which may be used as shoulder strap, for example.

Collapsible bags known heretofore are generally made of soft tissue which may be rolled or folded up, and are permanently connected with a carrying handle or strap. Such bags offer little protection to the objects contained therein. Bags having stiff walls so as to be capable of protecting their contents against shocks and external pressure, are not collapsible.

Collapsible packaging containers made of corrugated paper board, or the like, and having stiff walls and bottom, are known, but such containers are not suited for use as handbags, i.e. because they have no carrying handle or strap. Furthermore, once such containers are folded up, the bottom thereof, at least, must be permanently secured in its operative position in order to be able to carry the load of the goods packed in the container, so that the latter is no more collapsible.

Accordingly, it is an object of the present invention to provide a bag having stiff walls and a carrying strap, but being nevertheless easily collapsible when not in use.

Another object is to provide a collapsible bag having hingedly connected stiff panels for constituting the walls, the bottom and the lid thereof, and a strap for carrying the bag and locking the bottom of the bag against bursting open under the action of the weight of the object contained in the bag.

A further object is to provide a collapsible bag of the kind described having a separate carrying strap which becomes operatively connected with the body of the bag when the flaps or panels constituting the bottom and the lid of the bag are folded in to close the ends of the tubular body of the bag.

Still another object is to provide a collapsible bag with stiff walls and bottom which is simple in construction and inexpensive to make.

Other objects and advantages will appear as this specification proceeds, reference being now had to the drawings, in which:

FIG. 1 illustrates a portion of a foldable blank for the bag of this invention,

FIG. 2 is as top perspective view of the bag made from the blank of FIG. 1 and provided with a strap,

FIG. 3 is a bottom perspective view of the same,

FIG. 4 illustrates a modified form of the blank shown in FIG. 1, and

FIG. 5 is an end view of the bag made from the blank of FIG. 4.

The blank shown in FIG. 1 may be made of any suitable, stiff sheet material which is made pliable at the folding lines discussed hereinafter. Such materials are, for example, leather, plastic sheets, paper board or like fibre material, especially if coated with tissue. In the latter case, the various panels defined between the folding lines of the blank may be made separately and be hingedly connected with each other along the folding lines by means of the tissue coating.

The blank shown in FIG. 1 is first folded along parallel folding lines 3, 2 and 4 to constitute a prismatic tube having rectangular wall panels 31, 32, 31a and 32a, the tube being closed along the edge 1, e.g. through heat sealing in case of a blank of heat-sealable material. The edge 1 will then constitute a folding line of the tube. When collapsed to flat condition, the tube comprises two equal portions defined between the folding lines 1 and 2 lying flat upon each other. Near each end, the tube is provided with transverse folding lines 5, 6, 7, 8 and 9, 10, 11, 12, respectively defining flaps or panels 33, 34, 33a, 34a and 35, 36, 35a, 36a, respectively, for folding in to constitute a closure at each end of the tubular body of the bag.

The flap or panel 33 defined between the folding lines 1, 3 and 5 (FIG. 1, upper left) is formed with a pair of additional folding lines 13 and 14 starting at the point of intersection between the folding lines 1, 5 and 3, 5, respectively, and extending under an angle of 45° with these folding lines. The flap 33 is formed with a recess 21, the lateral edges of which meet the inclined folding lines 13 and 14 at points spaced a distance which is slightly greater than the width of the carrying strap described hereinafter. Subject to this condition, the recess 21 may be formed in any desired manner. In the example illustrated, the recess 21 is shown as being trapezoid. Generally speaking, the area defined between the inclined folding lines 13 and 14 should have a width at right angles to the folding line 5 which is smaller than half the length of the flap along the folding line 5, so that the folding lines 13 and 14 do not intersect each other.

Similar folding lines 15, 16; 17, 18; and 19, 20, respectively, and recesses 22, 23 and 24, respectively, are formed in the flaps or panels 33a, 35 and 35a defined between the folding lines 2, 7, 4; 1, 9, 3 and 2, 11, 4, respectively.

When the flat, collapsed tube is to be used as a bag, it is folded to rectangular section, and the flaps 34, 34a and 36, 36a are folded in to constitute the lid and the bottom respectively, of the bag, as shown in FIGS. 2 and 3, while the flaps 33, 33a and 35, 35a remain in a projecting position. When folded along the inclined folding lines 13--20, these flaps constitute closed channels or guideways through which a carrying strap 25 is threaded. This strap may take the form of an endless belt or loop, or it may be provided with a buckle or clasp (not shown) for adjusting the length of the strap. The strap may be placed in the body of the bag before or after folding in of the top and bottom flaps 34, 34a and 36, 36a as desired, but in any case it should be caused to extend through the channels or guideways formed by the flaps 33, 33a and 35, 35a and along the inside of the wall panels 31 and 31a.

Evidently, a portion of the strap 25 will extend from one end of the bottom 36, 36a of the bag to the other (FIG. 3), and when the strap is pulled away from the top side of the bag, the channels or guideways formed by the flaps 35 and 35a are bent in towards the outside of the bottom panels 36 and 36a. Now, when the objects to be carried in the bag are introduced therein, after the top panels 34 and 34a have been flipped open, the weight of the objects is transmitted through the bottom panels 36 and 36a to the flaps 35 and 35a and the strap 25. Thus, the bottom of the bag remains closed, while the to thereof is easy to open.

Obviously, the strap 25 may be pulled in the opposite direction relative to the body of the bag, so that the flaps 34, 34a constitute the bottom and the flaps 36, 36a constitute the top of the bag.

The blank shown in FIG. 4 in which like reference numerals denote like parts, differs from that shown in FIG. 1 in that slots 27, 28, 29 and 30 are provided along part of the folding lines 5, 7, 9 and 11, respectively, through which slots the strap 25 may pass from the inside of the flaps 33, 35 and 33a, 35a to the outside of the wall panels 31 and 31a, respectively, as shown in FIG. 5. This measure will assist in keeping the carrying strap 25 positioned when the top of the bag is open.

It will be appreciated that, when the bag is carried in the strap 25, all parts are interlocked so as to insure complete stability of the bag. However, as soon as the tension of the strap 25 is relaxed, e.g. when placing the bag upon a table, the top of the bag may be readily opened by lifting the flaps 34, 34a, or the bag may be taken completely apart and collapsed to flat condition.

The width of the top and bottom flaps 34, 34a and 36, 36a at right angles to their respective folding lines 6, 8, 10, 12 should be greater than half the width of the wall panels 31, 31a, and smaller than this width, so as to insure a suitable overlapping, as shown in FIG. 2.

Referring to FIGS. 1 and 4, it will be observed that the lateral margins of the lid flaps 34, 34a and bottom flaps 36, 36a are coincident or coextensive with the lateral hinge margins 2--4. Additionally, the end walls 31, 31a have hingedly connected to the upper margins 5, 7 and bottom margins 9, 11 a series of polygonal segments conveniently described as sleeve-forming channels which are clearly illustrated in FIGS. 2 and 3 at 33a, for example. These channels are formed when the cover or lid panels 34, 34a and 36, 36a are in juxtaposed relation as is clearly evident from FIG. 2.

The sleeve-forming channels comprise a pair of isosceles triangular segments hingedly connected to the lateral margins of the rectangular lid flaps, see FIGS. 1 and 4, and include lower hinge margins at 13--20, each respectively comprising opposite sides of a trapezoidal segment 33, 33a, and 35, 35a, respectively. These trapezoidal segments have their longer base 5, 7, 9, and 11, respectively, hingedly connected at the upper or lower ends of the end walls 31, 31a.