Drawstring Construction

Abstract

A drawstring including an elongate flexible element for extension about the neck of a bag, an enlarged gripping member on one end of the elongate element, and a retaining member on the other end of the elongate element configured for interfitting engagement with the gripping member for retention of the elongate element about the neck of the bag.

Description

BACKGROUND OF THE INVENTION

The invention is concerned with drawstring bags, and particularly drawstrings for such bags. As is well known to those versed in the art, drawstring bags are quite old, and the construction of drawstrings has not changed greatly over the years. Thus, even in the mass production of drawstring bags, the assembly and formation of the drawstrings has required considerable handwork, the use of automation not being possible or not economically justified. While prior drawstring construction has utilized modern materials, such as plastics, and modern forming and securing operations, such as molding and thermosealing, there has still been required the fabrication and assembly of several parts which involves substantial cost.

SUMMARY OF THE INVENTION

It is, therefore, an important object of the present invention to provide a unique drawstring construction for a bag which is capable of integral formation, as of thermoplastic material say by molding, or otherwise, to effect substantial savings in costs, both by way of labor and materials.

It is another object of the present invention to provide a drawstring construction of the type described which overcomes the above-mentioned difficulties, being capable of economic manufacture as a single integral molded part, and which is adapted for assembly together with a bag without the use of additional parts, or extraneous materials, such as adhesives.

It is a more particular object of the present invention to provide a drawstring construction having the advantageous characteristics mentioned in the preceding paragraphs which is staunch, durable, reliable and economical in construction and manufacture, and which can be economically assembled with a bag by hand or by automatic equipment, as desired, to effect substantial savings in costs.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings, which form a material part of this disclosure.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, which will be exemplified in the construction hereinafter described, and of which the scope will be indicated by the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view showing a drawstring bag constructed in accordance with the teachings of the present invention.

FIG. 2 is a longitudinal view showing a single drawstring of the bag of FIG. 1 apart therefrom, the drawstring being partly broken away and partly in section to conserve space and illustrate detail.

FIG. 3 is a longitudinal view similar to FIG. 2, but taken from the left side thereof, also partly broken away and partly in section.

FIG. 4 is a transverse sectional view taken generally along the line 4--4 of FIG. 2.

FIG. 5 is a transverse sectional view taken generally along the line 5--5 of FIG. 2.

FIG. 6 is a fragmentary perspective view, partly in section, illustrating certain details of the instant drawstring before assembly.

FIG. 7 is a partial perspective view, partly in section, similar to FIG. 6, but illustrating the drawstring subsequent to assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now more particularly to the drawings, and specifically to FIG. 1 thereof, a bag is there generally designated 10, which may be essentially conventional including a pair of generally congruent facing walls 11 and 12 combining to define an open bag neck 13. The open bag end or neck 13 may be provided with suitable means for receiving drawstrings, such as a plurality of eyelets 14, or other suitable receiving means, which receive a pair of drawstrings 15. In the conventional manner, the drawstrings 15 may each extend about the bag neck 13, and be drawable to close or selectively constrict the bag neck. The drawstrings may be conveniently tied, or otherwise secured together to maintain the bag neck closed.

Each of the drawstrings 15 is shown in greater detail in FIGS. 2-7. Particularly in FIG. 2 each of the drawstrings 15 is shown as including an elongate, generally straight, filamentary element 20 having a resilient flexibility sufficient for bending and tying, as described above. The elongate element may be fabricated of suitable plastic, or other desired material, advantageously being formed by injection molding. The elongate element 20 may have a cross-sectional configuration, as best seen in FIGS. 4 and 5, being approximately rectangular but having one side arcuate, as at 21. The elongate element 20 has one end region 22 of reduced cross-section, and is provided on the distal end thereof with an enlarged gripping member 23.

The enlarged gripping member 23 may be generally cylindrical or frusto-conical, extending generally longitudinally outwardly from the reduced region 22 of elongate element 20, and terminating at its larger, outer end 24. The enlarged gripping member 23 may be generally hollow, having a generally cylindrical cavity 25 extending generally axially inwardly through the outer gripping member end 24 and terminating short of the inner gripping member end 26. That is, the internal hollow formation 25 may terminate at an inner end wall 27. A through opening 28 may be formed extending through the inner wall 26 of the gripping member 23 and opening through the internal cavity wall 27, into the hollow 25. The through opening or bore 28 may be of generally semi-cylindrical cross-sectional configuration, see FIGS. 5, 6 and 7, and has its generally flat side substantially flush with the adjacent region 22 of elongate element 20. The through opening 28 enters through the internal wall 27 spaced from the side wall of the hollow 25, and combines with the wall 27 to define a shoulder 29, see FIGS. 2, 6 and 7, adjacent to the opening 28 and facing longitudinally outwardly of the gripping member 23.

The other end of the elongate member 20, remote from the enlarged gripping member 23, is provided with an enlarged retaining member 30. The retaining member 30 may be generally of wedge-shaped configuration, or otherwise suitably configured to have a longitudinally outwardly extending taper. In particular, the retaining member 30 may be located on the rounded side 21 of the elongate element 20, having an inclined or oblique outer surface 31 extending from the outer end 32 of the retaining member longitudinally inwardly and obliquely outwardly. The inner end of the oblique surface 31 terminates in a transversely inwardly extending surface 33, which may be generally normal to the axis of the elongate element 20. The transverse surface 33 may be considered as a shoulder on the elongate element facing longitudinally inwardly from the retaining member 30.

At a location on the elongate element 20 adjacent to but spaced longitudinally inwardly from the retaining member 30, there is provided a limiting member 35, which may assume the form of a pair of generally rectangular lugs or ears 36 outstanding laterally oppositely from respective side edges of the elongate element 20. The overall lateral dimension of the limiting member 35 is considerably greater than that of the elongate element 20, and also of the through opening 28, for a purpose appearing presently.

In assembly, as shown in FIG. 1, each of the drawstrings 15 is threaded about the bag neck 13 so that the opposite ends of each drawstring are proximate to each other and disposed on opposite sides of the bag. Further, the enlarged retaining member of each drawstring 15 is passed longitudinally outwardly through the opening 28 of the associated gripping member 23. By the inherent resilient flexibility of the plastic material, and by the wedge-shaped configuration of the retaining member 30, the latter may be snap-engaged through the receiving openings 28 into the internal hollow 25, as seen in FIG. 7. Excessive movement of the elongate element 20 through the opening 28 is prevented by engagement of the limiting member 35 with the gripping member wall 26. By this means the retaining member 30 is effectively held within the internal hollow 25. Further, withdrawal of the retaining member 30 from the internal hollow 25 is positively prevented by limiting abutment of the retaining member edge or shoulder 33 with the internal hollow surface or shoulder 29.

Thus, a very quick and easy assembly is enabled by provision of the instant drawstrings 15, which assembly may lend itself to automation to any desired extent. Further, the drawstrings 15 may each be entirely integral and fabricated of suitable plastic, so as to admit of economical mass production manufacture, as by injection molding, or other suitable means.

From the foregoing, it is seen that the present invention provides a drawstring for a bag which is extremely simple in construction, manufacture and assembly, capable of secure reliability throughout a long, useful life, and which otherwise fully accomplishes its intended objects.

Although the present invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be made within the spirit of the invention.

Claims

What is claimed is:

1. A drawstring for a bag fabricated of resilient material and comprising an elongate flexible element for extension about the neck of the bag, an enlarged gripping member on one end of said element and having a through opening, a retaining member on the other end of said element and snap engageable through said opening to retain said element about the neck of a bag, said element and gripping member and retaining member all being integrally fabricated of thermoplastic material, said gripping member comprising a body extending longitudinally from said one element end and having an interior hollow opening longitudinally away from said element, said through opening being adjacent to said one element end and communicating with said interior hollow for extension of said retaining member through said through opening into said interior hollow, said through opening terminating at an internal shoulder facing into said hollow, said retaining member including a retaining shoulder facing away from said one element end for retaining abutment with said internal shoulder when said retaining member is in said hollow, said retaining member being generally wedge-shaped and tapering longitudinally outwardly outwardly of said elongate element away from said retaining shoulder, and an enlarged limiting member on said element adjacent to and spaced from said retaining member for limiting engagement with said enlarged gripping member.

2. A drawstring according to claim 1, said through opening being of a generally semicircular configuration located contiguous to said flexible element and having one internal surface generally flat and substantially flush with one external surface of said flexible element, and said flexible element adjacent to said retaining member being of generally semicircular cross section for conforming and nonrotative engagement in said through opening.