US3739430A

US3739430A - Bundling strap

Info

Publication number: US3739430A
Application number: US00181347A
Authority: US
Inventors: S Kohke
Original assignee: Thomas and Betts Corp
Current assignee: ABB Installation Products Inc
Priority date: 1971-09-17
Filing date: 1971-09-17
Publication date: 1973-06-19
Anticipated expiration: 1990-06-19
Also published as: BE788909A; FR2155280A5; GB1380116A; JPS4840596A; JPS517433B2; CA993176A; SE384351B; NL7212642A; DE2243610B2; DE7232753U; DE2243610A1; IT965366B; DE2243610C3

Abstract

An improved self-locking bundling strap comprising, in one form, a plurality of pairs of spaced, generally transverse narrow slits of predetermined length extending from the edges of the strap inwardly towards the center of the width of the strap, each pair being separated by a selectively proportioned center portion, to facilitate the severance of an excess portion thereof by rotatably twisting said portion while substantially preserving the initial strap strength and flexibility. Other embodiments include obliquely angled slits having either a straight or curvilinear contour.

Description

United States Patent 1 91 Kohke 6/1965 Schwester et al. 24/16 PB [5 BUNDLING STRAP 3,186,047

[75] Inventor: Stephen Kohke, Bridgewater FOREIGN PATENTS OR APPLICATIONS Township, 1,278,571 10/1961 France 24/16 PB [73] Assignee: Thomas & Betts Corporation, 1,435,102 3/1966 France 24/16 PB Elizabeth, NJ. 1 Primary Examiner--Donald A. Griffin Filed; p 1971 Attorney-David Teschner and Jesse Woldman 21 Appl. No.: 181,347 I 57 ABSTRACT 1 US Clmm 24/16 PB An improved self-locking bundling strap comprising, in [51] Int. Cl 63/00 one form, a plurality of pairs of spaced, generally trans- [58] Field R 17 B verse narrow slits of predetermined length extending 24/17 A 17 206 A PB 73 from the edges of the strap inwardly towards the center P 74 of the width of the strap, each pair being separated by a selectively proportioned center portion, to facilitate [56] Reierences Cited the severance of an excessportion thereof by rotatably 1 I g 1 twisting said portion while "substantially preserving the UNITED STATES PATENTS initial strap strength and flexibility. Other embodiments 3; rfi t lt include obliquely angled slits having either a straight or s a er 2,361,506 10 1944 Smith 24/16 PB ux curl/meat contour 3,022,557 2/1962 Logan 24/16 PB UX 9 Claims, 12 Drawing Figures E 1 0 I l I 1 a2 June 19, 1973 BUNDLING STRAP BACKGROUND OF THE INVENTION P. Schwester et al., and entitled Self-Clinching Bundling Strap assigned to the assignee of the instant invention, are generally constructed in such manner that after the strap has been wrapped about the articles to be bundled the excess of the strap body portion not required for such bundling may be severed therefrom. In

general practice such severing is accomplished by means of installation tools which not only attach and tighten the strap to the articles to be bundled, but also cause severing of the excess portion of the body. Comparatively, any type of cutting devices such as side cutter's, shears, scissors or the like may also be employed to remove the excess. It is obvious from the prior art method of employment of the straps that a tool is essential for removal of the excess portion and sufficient space is required to permit the tool to be employed. The absence of the tool or the inability to employ the same results in a strap which has an excess portion of its body extending beyond the loop portion, which is both unattractive and which may interfere with the use of the bundled articles. Prior art methods for accomplishing the severance of the excess portion which included, for example, selectively scoring or notching the body portion of the strap, have generallyproved unsatisfactory because of the severe reduction in flexibility and strength resulting therefrom.

SUMMARY OF THE INVENTION The present invention overcomes the difficulties and limitations noted above with respect to prior art devices by providing a steplessly variable, selectively severable bundling strap advantageously arranged to avoid the necessity for the use of cutting or severing tools to accomplish the severance of a desired portion thereof from the remaining strap body. One or more pairs of generally transverse narrow slits, arranged either in opposing or offset relation, are introduced into the body portion of the strap and extend from the sides towards the center of the width thereof a predetermined distance to provide a generally centrally disposed uncut portion selectively proportioned to maintain adequate strength and flexibility in the body portion for the use contemplated, while permitting the portions of the strap body adjacent thereto to be conveniently severed by axially rotating one portion in relation to the other, as by twisting or the like. The slits extend between, and communicate with, both the upper and lower body portion surfaces along either equal or unequal lengths the'reat, the latter arrangement facilitating increased coplanar bending flexibility in a preferred direction. Additionally, the slits may be obliquely angled with respect to the longitudinal axis of the body portion, and formed either straight or curved, the. latter configuration being extremely useful where it is desired to maintain the severed central portion within the confines of the outer ends of the strap. It is therefore an object of this invention to provide an improved bundling strap.

It is another object of this invention to provide means for effecting the directionally selective severability of a portion of a bundling strap.

It is a further object of this invention to eliminate the need for tools in severing the excess portion of a bundling strap.

It is still another object of this invention to provide a means for severing the excess portion of a bundling strap from the remainder thereof by twisting.

It is still a further object of this invention to provide an improved bundling strap arrangedto maintain the bending flexibility thereof while: rendering a portion thereof particularly amenable to severance by twisting.

It is yet a further object of this invention to provide pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principles of the invention and the best modes which have been contemplated for carrying them out.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of a bundling strap constructed in accordance with the concepts of the invention.

FIG. 2 is a side elevational view of the bundlingstrap of FIG. I wrapped about a plurality of articles.

FIG. 3 is a fragmentary. side elevational view of a portion of the bundling strap of FIG. I wrapped about an article in a manner different than that shown in FIG. 2.

FIG. 4 is a front perspective view of the bundling strap of FIG. 1 showing the manner in which the excess body portion may be removed therefrom by twisting.

FIG. 5 is a fragmentary top plan view of a portion of the body portion of the bundling strap of FIG/1 showing the effect of transverse bending thereon.

FIG. 6 is a fragmentary side elevational view of a por' tion of the body portion of the bundling strap of FIG. 1 showing the effect of coplanar bending. thereon.

FIG. 7 is a front transverse sectional view of a portion of the body portion of the bundling strap of FIG. 1

taken along the lines 7--7 of FIG. 1.

FIG. 8 is a front transverse sectional view of a portion of a bundling strap constructed in accordance with another embodiment of the invention.

FIG. 9 is a fragmentary perspective view of a portion of the bodyportion of the bundling strap of FIG. 1 showing the manner in which a portion may be removed therefrom by twisting.

FIGS. 10, Hand 12 are fragmentary perspective views of a portion of the body portion of a bundling strap constructed in accordance with further embodiments of the invention.

Similar elements are given similar reference characters in each of the respective drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to FIGS. 1 and 2, there is shown a bundling strap 20 constructed in accordance with the concepts of the invention, and comprising a head portion 22 having a transverse aperture 24 therethrough, and

engaging means in the form of a pawl 26 extending at least partially into aperture 24. Extending from the head portion 22 is a generally flat elongated body portion 28 terminating in a preferably tapered tail portion 30. Extending inwardly from the opposing sides 32, 34 of the body portion 28 towards the center of its width, and extending between and communicating with both the upper and

lower surfaces

36, 38 respectively, of body portion 28, are a plurality of generally transverse narrow slits 40 disposed along the length of the body portion 28 in generally spaced relationship. Although shown in FIG. 1 as arranged in generally opposed aligned relationship, slits 40 may be positionally altered to provide an essentially'staggered arrangement as at 42 in FIG. 12, and may be aligned in generally oblique angular relationship with the longitudinal axis of body portion 28, as at 44 in FIG. 10, without departing from the spirit of the invention. Additionally, slits 40 may be selectively formed in generally curvilinear fashion as shown at 46 in FIG. 11, the various advantages of such modifications being more particularly described below. Although

slits

40, 42, 44 and 46 may be formed during the manufacture of the strap 20, as by molding or the like, it has been found that the subsequent formation of such slits by the use of a razor-like slitting tool applied to the formed strap generally results in the added advantage of substantially reducing the twisting force re quired to effect the desired severance without adversely affecting the flexibility or tensile strength of the strap. Extending longitudinally along the body portion 28 of bundling strap intermediate the opposing slits is an uncut central portion 48, more clearly shown in FIG. 7. The cross-sectional area of portion 48 is selectively proportioned to insure adequate strap strength and flexibility while enabling one portion of the body portion 28 to be conveniently removed from the remaining length thereof merely by applying a rotational twist thereto, directionally as shown at 52 in FIG.

9, thus avoiding the need for special tools to effect, for 7 example, the desired removal of the excess portion of said body portion'28 extending beyond the head portion 22 after the bundling strap 20 has been wrapped about one or more articles (FIG. 2), and the tail portion 30 inserted into the head portion aperture 24 and drawn therethrough, and locked by means of pawl 26, as shown for example, in FIG. 4. Depending upon the type of material from which the bundling strap 20 is formed, and the strength and flexibility desired, the ratio of the cross-sectional area of the central portion 48 to the transverse cross-sectional area of the body portion 28 may vary from about 50 percent to about 95 percent thereof. Examples of plastic materials suitable for use within the aforementioned range may include,.

but are not limited to, nylon, delrin, polypropylene, polyethylene, and polyvinyl chloride, and other nonmelt formable materials. Where desired, the slits 40 may be disposedin the body portion 28 in such manner as to form a central portion 54 (FIG. 8) having a crosssection generally defining an isosceles trapezoid, substantially as shown. Such arrangement may be particularly advantageous where, for example, it is either necessary or desirable to provide increased coplanar flexi bility in a preferred direction. The particular configuration illustrated in FIG. 8 will, for example, permit the body portion of a bundling strap such as 20, modified accordingly, to be more readily coplanarly flexed downwardly as directionally indicated by the arrow 56 in FIG. 6, while offering greater resistance to flexing in a direction opposite thereto, in supplement to the inherent flexibility of the bundling strap 20 absent the inclusion of such slits therein. Although the terminating edges 49, 51 (FIG. 7) and 53, (FIG. 8) of the

central portions

48 and 54, respectively, are shown as substantially linear, it will be readily apparent to those skilled in the art that such edges may be curvilinearly contoured or otherwise varied without departing from the spirit of the invention. The resistance of the body portion 28 to lateral deflection when subjected to a force applied directionally as indicated by

arrows

58, 60 in FIG. 5 is not appreciably decreased as a result of the presence, of slits 40 therein. because of the close, substantially abutting relationship of the walls defining slits 40. For example, where aforce such as that indicated by the arrows S8, 60 in FIG. 5 is applied to the body portion 28, the side of the body portion 28 to the right in FIG. 5 is urged into compression, while the opposite, or left, side is subjected to a tensile force. As shown, the slits 40 to the left in FIG. 5 are caused to widen slightly while those on the right side are caused to close, thereby resisting further deflection within the inherent compressive strength of the material employed. As a result of the aforementioned properties, the necessity for substantially increasing the size of bundling strap required in a particular application beyond that generally employed in unslit prior art straps is advanta I geously avoided, while such structure provides a convenient means for effecting the severance of a selective portion thereof without the need for tools or other cutting devices. The further advantages of the disclosed arrangement may be more fully appreciated by reference now to FIG. 3. As shown therein, bundling strap 20 may be wrapped about an article such as in such manner as to cause a relatively severe coplanar deflection of the body portion 28 at the point of entry of said portion 28 into the strap head portion 22, as at 82. In the event strap 20 were transversely scored or notched, as is provided in many commonly employed prior art bundling straps, such deflection would tend to cause a weakening or parting of the strap at the point of deflection, thereby resulting in a loss of retention and engagement. However, because of the maintenance of the integrity of the central body portion of the instant device, and the corresponding retention of coplanar flexibility and tensile strength resulting from the unique arrangement of the slitted structure disclosed herein, such problems are essentially avoided.

As may be more clearly seen in FIGS. 7 and 8, each of the

central portions

48 and 54 are so proportioned as to provide a substantially uninterrupted area for engagement with the bundling strap pawl 26, thus permitting essentially infinitely variable stepless engagement between the pawl 26 and body portion 28 independent of the position of slits 40.

As indicated heretofore, slits 40 may be modified as at.44 and 46 in FIGS. 10 and 11, respectively, within

edges

72, 74 formed by the communication of the planar slit surfaees 64 with the respective body portion sides 76, 78 (FIG. It will be readily apparent to those skilled in the art that other slit configurations and arrangements employing a-combination of

slits

40, 42, 44 and 46, or' suitable variations thereof, may be readily utilized without departing from the spirit of the invention.

The longitudinalspacing between

slits

40, 42, 44 or 46 may be selectively arranged to provide either a uniform, nonuniform, continuous, or discontinuous pattern, depending upon the incremental variation desired and/or use contemplated. Longitudinal slit spacing in the range of from about one thirty-second to about three-eighths inches has been found to be generally adequate for most purposes where it is desired to limit the extent of protrusion of the remaining strap body portion 28 beyond the strap head 22 after severance. It will be readily apparent, however, that such rangeis not intended to be limiting, but may be suitably varied as desired. For example, slits 40, 42, 44 or 46 may be longitudinally disposed in relatively close adjacent relationship along a first predetermined length of body portion 28, and more widely spaced along a secondpredetermined length thereof. It will also be readily apparent to those skilled in the art that slits 40, 42, 44 or 46 may be so proportioned as to provide differing crosssectional dimensions along the length of body portion 28, where, for example, it is necessary or desirable to selectively vary the flexibility thereof. 7

The embodiments of the invention in which the exclusive property or privileges are claimed are defined as follows: 1 v i 1. In a bundling strap of'the type having a head end portion having a transverse aperture therethrough, a tail end portion, an elongated body portion therebetween having afirst surface, a second surface, a first side and a second side, and proportioned to be received within said head end portion transverse aperture, and engaging means in said head end, portion for stepless coacting engagement with at least one of said first and second surfaces of said body portion, the. improvement comprising: said 'body portion having at least one pair of slits for enhancing the severance of a selective length of said body portion from the remainder thereof, each slit of a pair thereof extending inwardly, respectively, from an opposite one of said body portion first and second sides a predetermined distance towards the center of the width of said body portion providing a central portion thereat, each of said slits further extending between and communicating with said body portion first and second surfaces, each of said slits being generally curvilinear and forming generally arcuate segments adjacent said first and said second sides of said body portion and extending longitudinally slightly beyond said body portion central portion thereby providing a partial shield about said central portion upon the severance of said body portion intermediate said pair of slits.

2.ln a bundling strap of the type having a head end portion having a transverseaperture therethrough, a tail end portion, an elongated body portion therebetween having a first surface, a second surface, a first side and a second side, and proportioned to be received within said head end portion transverse aperture, and engaging means in said head end portion for stepless coacting engagement with at least one of said first and second surfaces of said body portion, the improvement comprising: said body portion having at least one pair of slits for enhancing the severance of a selective length of said body portion from the remainder thereat, each slit of a pair thereof extending inwardly, respectively,

from an opposite one of said body portion first and sec-.

ond sides a predetermined distance towards the center of the width of said body portion, each of said slits further extending between and communicating with said body portion first and second surfaces, each of said slits communicating with said body portion first surface along a first predetermined length,and communicating with said body portionsecond surface along a second predeterminedlength different than said first predetermined length, wherein the area of said body portion in termediate said pair of opposingly disposed slits has a cross-section generally defining an isosceles trapezoid providing a greater surface area and resistance to coplanar deflection at the one of said body portion first and second surfaces adjoining the longer of the parallel sides defining said isosceles trapezoidal area.

3. The improvement as definedl in claim 2, wherein said first predetermined length is shorter than said second predetermined length.

4. The improvement as defined in claim 2, wherein said first predetermined length is longer than said second predetermined length.

5. The improvement as defined in claim 2 wherein said isosceles trapezoidal area comprises a maximum of about percent of the cross-sectional area of said body portion as measured generally transverse to the longitudinal axis thereof. i

6. The improvement as defined in claim 2 wherein said isosceles trapezoidal area comprises at least about 50 percent of the cross-sectional area of said body portion as measured generally transverse to the longitudinal axis thereof.

7. The improvement as defined in claim 2 wherein said isosceles trapezodial area is in the range of about 50 percent to about 95 percent of the cross-sectional area of said body portion as measured generally transinches to about three eighths inches.

Claims

1. In a bundling strap of the type having a head end portion having a transverse aperture therethrough, a tail end portion, an elongated body portion therebetween having a first surface, a second surface, a first side and a second side, and proportioned to be received within said head end portion transverse aperture, and engaging means in said head end portion for stepless coacting engagement with at least one of said first and second surfaces of said body portion, the improvement comprising: said body portion having at least one pair of slits for enhancing the severance of a selective length of said body portion from the remainder thereof, each slit of a pair thereof extending inwardly, respectively, from an opposite one of said body portion first and second sides a predetermined distance towards the center of the width of said body portion providing a central portion thereat, each of said slits further extending between and communicating with said body portion first and second surfaces, each of said slits being generally curvilinear and forming generally arcuate segments adjacent said first and said second sides of said body portion and extending longitudinally slightly beyond said body portion central portion thereby providing a partial shield about said central portion upon the severance of said body portion intermediate said pair of slits.

2. In a bundling strap of the type having a head end portion having a transverse aperture therethrough, a tail end portion, an elongated body portion therebetween having a first surface, a second surface, a first side and a second side, and proportioned to be received within said head end portion transverse aperture, and engaging means in said head end portion for stepless coacting engagement with at least one of said first and second surfaces of said body portion, the improvement comprising: said body portion having at least one pair of slits for enhancing the severance of a selective length of said body portion from the remainder thereat, each slit of a pair thereof extending inwardly, respectively, from an opposite one of said body portion first and second sides a predetermined distance towards the center of the width of said body portion, each of said slits further extending between and communicating with said body portion first and second surfaces, each of said slits communicating with said body portion first surface along a first predetermined length, and communicating with said body portion second surface along a second predetermined length different than said first predetermined length, wherein the area of said body portion intermediate said pair of opposingly disposed slits has a cross-section generally defining an isosceles trapezoid providing a greater surface area and resistance to coplanar deflection at the one of said body porTion first and second surfaces adjoining the longer of the parallel sides defining said isosceles trapezoidal area.

3. The improvement as defined in claim 2, wherein said first predetermined length is shorter than said second predetermined length.

5. The improvement as defined in claim 2 wherein said isosceles trapezoidal area comprises a maximum of about 95 percent of the cross-sectional area of said body portion as measured generally transverse to the longitudinal axis thereof.

7. The improvement as defined in claim 2 wherein said isosceles trapezodial area is in the range of about 50 percent to about 95 percent of the cross-sectional area of said body portion as measured generally transverse to the longitudinal axis thereof.

8. The improvement as defined in claim 2, wherein said body portion comprises a plurality of said pairs of slits longitudinally disposed along the length of said body portion.

9. The improvement as defined in claim 8, wherein said slits are generally longitudinally spaced one from another in the range of from about one thirty-second inches to about three-eighths inches.