US1783192A - Strapping joint - Google Patents

Description

Dec. 2, 1930. l w LESUE 1,783,192

STRAPPING JOINT Original Filed March l2, 1928 `2 Sheets-Sheet l www' J. W. LESLIE STRAPPING JOINT Dec. 2, 1930 Original Filed March 12. 1928 2 Sheets-Sheet 2 Patented Dec. 2, 1930 UNITED STATES PATENT oFFIcE JOHN' W. LESLIE, 0F EVANSTON, ILILINOIS,A ASSIGNOR, BY MESNE ASSIGNMENTS, T0 SIGNODE STEEL STRAPPING COMPANY, A CORPORATION OF DELAWARE STBAPPING JOINT Application filed March 12, 1928, Serial No. 260,911. Renewed March 1G, 1929.

yof the size or character of deformation that would provide maximum resistance to separation. Either joint strength is sacrificed t0 maintain the strapping strength, or vice versa. In other Words, the tensile strength of the strapping at the seal-joint after the formation thereof has been very considerably decreased in the production of a strong joint or union between the overlapping portions of the strap or else the inherent strength of the joint or union between strap ends has been very materially decreased in order that the tensile strength of the strap at or adjacent the joint or union may be maintained.

One of the objects of my invention is to provide an improved seal-joint for metal strapping in which maximum strength of joint is obtained without sacrificing tensile strength of the band between the joined ends of the strapping.

Another object is to provide a seal-,joint that is simple, reliable, inexpensive and readilyvproduced.

Embodiments of my invention are illustrated in the accompanying drawings Where- 1n:

Figure 1 is a perspective view of a package in the form ofy a box showing the application of strapping with my seal-joint;

Figure 7 is a bottom plan view of the sealjoint;

Figure 8 is a side elevation of a further modification of the seal-joint as applied to wire-tying binding.

I attain the desired end of maximum strength of union between overlapping portions of binder strap without material sacritice of strap strength at or adjacent the union by providing a joint wherein the uniting deformation or deformations in the central region of the joint, where the tensile strains are more equally shared by the overlapping strap portions, have greater or more intense interlocking properties than do deformation or deformations near the ends of the joint where the tensile strains must be borne in greater proportion by only one of the overlapping strap portions.

In general, the seal-joint illustrated in Figures 1 to 4 inclusive comprises a metal sleeve A closely encircling opposite and overlapped ends B and C of a steel strapping band D with relativelyintense deformation of the sleeve and overlapped ends B and C at their midpoints as shownin Figure 4 and less intense deformation at opposite ends of the midpoint of the seal-joint as shown Figure 3. Sleeve A is constructed of sheet metal and closely engages strap ends B and C and serves to prevent lateral movement of the ends away from one another as well as assisting in the formation of an eflicient joint. The particular type of deformation of the sleeve and overlapped strap ends illustrated in Figl portions juxtaposed ures 2 to 4 has been fully described in my co-pending application for patent onstrapping joints, Serial No. 314,216, tiled October 22,1928.

Brielly, this type of deformation consists in the provision of pairs of indentations 10 and 11 overla ping strap ends, the indentations of ,e'cli pair being in edgewise alinement and gradually decreasing in depth away from one another with their deepest to form abutting edge portions of strap ends B and C.

My present invention relates more particularly to the arrangement of the deformations, each of which serves as interlocking mea-ns for the strap ends, in such a manner, as to provide maximum deformation and hence maximum joint strength at the midpoint of the seal-joint as represented by the pairs 13 of indentations and in addition thereto other and lesser deformation of the sleeve and strap ends at opposite ends of the joint beyond the mid portion as represented by the pairs 14 and 15 respectively of indentations.

A seal-joint constructed as herein described possesses maximum joint strength because of the intense deformation or interlocking of the band endsat its mid-point by pairs 13 of the indentations butsuch structure alone also .weakens the tensile strength of the strappingl at the mid-point of the joint. This weakening of the strap at the mid-point of the joint is permissible due to the fact that the strap ends overlap at this point and each sustains a part of the tension applied to the joint. The lesser deformation and interlocking of the strap ends adjacent to the ends of the joint and on each side of the mid-portion weakens the v strap less than the greater deformation at the mid-point so that the tensile strength of the strap at the ends of the joint, where the load is not divided between overlap ing portions, will be greater than at the mid-point where the overlapping; portions divide the load.v And the formation of more intense deformations intermediate the ends of the joint does not weaken the joint as a whole because the tension at this point is distributed between both overlapping portions.

In Figure 5 I have shown a modification of the seal-joint in which the deformation or interlocking of sleeve E and strap ends B and C is accomplished by transversely shearing relatively large portions 20 of the sleeve and strap ends at their mid-point and at opposite edges and in bending downwardly so as to provide abutting edges of the strap ends. This central or mid-point deformation forms a relatively secure joint but in itself greatly decreases the tersile strength of the strap ends at the mid-part of the joint. Additional and lesser portions 21 at the'opposite edges and adjacent opposite the sheared portions in opposite sides respectively of the I sleeve and ends of the sleeve and overlapped strap ends are shearcd away and bent downwardly, thus providing lesser deformations which better distributes the tensile strain upon the joint so as to relieve the mid-point of such strain as might otherwise result in rupture.

In Figures 6 and 7 I have illustrated another modiiied form of the seal-joint as applied to that type of joint illustrated and described in United States Patent to Flora No. 1,252,680. This type of joint consists of a split sleeve E received about the overlapped strap ends B and C and the parts thus assembled deformed by the application of edgewise pressure at 22 and 23. This deformation in the present'joint is relatively intense soas to provide an extremely tight joint and interconnection between the overlapped strap ends. As in the case of the preferred form of seal-joint and that form shown in Figure 5, however, this intense deformation results in somewhat weakening the strap strength at the mid-point of the joint. Additional edgewise deformations 24 of lesser intensity than shown at 22 and 23 are provided in the parts at opposite sides of the mid-point and adjacent to the ends of the overlapped strap portions. The presence of these lesser and additional deformations results in a distribution of strain over a greater area of the inter-connected straps ends so as to relieve the mid-point of the joint from such strain as might otherwise result in rupture due to the weakening of the material through stretching and the like occurring as the result of the relatively intense deformation.

In Figure 8 I have shown another modified form of the strapping joint as applied to wire tying. It has been the practice in the past to tightly wind the overlapped ends 28 and 29 about one another for their inter-connection. If the ends are wound too tightly, however, so as to greatly increase the inter-locking of the ends, the wire is weakened through stretching so that the joint will break when under its normal stress.

In carrying out my invention as ap lied to wire tying, I clamp the -ends 30 of t e portions 28 and 29 against movement by gripj pers 31 and twist the overlapping wires in opposite directions at points 32 and 33 at an equal distancefrom one another and from the ends 30.` I have illustrated diagrammatically slotted pinions 34 and gears 35 driven in opposite directions to rotate the pinions for this purpose.

As a result of twisting the overlapped wire ends in opposite directions at 32 and 33, a relatively intense twisted and interlocked portion 38 is formed at the mid-point of the overlapped wire ends and less intensely twisted and interlocked portions 40 are formed on each side of th`e portion 38.

The joint so formed possesses all of the admations of va vanta-ges of the close interlock produced by the tightly twisted portion 38 and of relatively great tensile strength due to the distribution of rectilinear stresses upon Wires throughout the central part of the overlapping vvire ends to relieve the central portion of an otherwise concentrated application of stresses upon a single wire.

v What I claim is new and desire to secure by Letters Patent of the United States is:

1. In a joint for interconnecting overlap- `ping binder ends, a plurality of deformations therein for interlocking the binder ends, said deformations being of lesser intensity at the ends of the joint than at the central portion of the joint.

2. A joint for interconnecting overlapping binder ends comprising relatively great crosssectional deformation at substantially the mid-point of the overlapping ends and other and lesser cross-sectional deformations of those portions at the opposite sides of.,` the greater deformation.

3. lln a joint for interconnecting overlapping binder ends, a plurality of interlocking deformations formed in the binder ends, the deformations at the mid-portion of the joint being relatively intense and the deformations adjacent the ends of the joint being less intense 4. A binder joint comprisinga deformed binder end, a second deformed binder end, means for holding the ends in adjacent overlapping and interlocked positions, the de- "T formations at the central part of the joint and at those parts adjacent the ends being of varying magnitude whereby the decrease in thetensile strength at that portion having deformations of greater magnitude is compensated for the distribution of stresses' throughout the joint by other deformations of lesser magnitude.

` 5. A joint for interconnecting overlapping binder ends comprising a plurality of deformagnitude distributed throughout the length of the joint whereby the decrease in tensile strength at that portion having a deformation of greater magnitude is compensated for by distribution of stresses throughout the joint made possible by the deformations of lesser magnitude.

6. A joint for interconnecting overlapping portions of metal straps comprising a plurality-of interlocking deformations distributed throughout the length of the overlapping portions formed in the overlapped strap ends, the transverse cross-sectional deformation of the strap ends being greatest at their mid-point of the joint. r

7 A joint for interconnecting overlapping portions of metal taps comprising a plurality of interlocking deformations distributed throughout the length ofl the overlapping portions formed in the overlapped strap ends. the transverse cross-sectional deformation of the stra ends being greatest at their midpoint o the joint, and means for maintaining the engaging faces of the strap ends in engagement with one another.

8. A joint for interconnecting overlapping portions of metal straps comprising av metal sleeve tightly encircling the overlapped portions of the straps, a plurality ofv interlocking deformations distributed throughout the length of the joint, the transverse cross-sectional deformation of the overlapping strap ends being greatest at their mid-point.

9. A joint for interconnecting overlapping portions of a binder strap comprising a plurality of interlocking deformations formed in the overlapping portions of the strap, the deformations near the ends of the joint being individually of less magnitude than the deformations nearer the center thereof. 4

10. A joint for interconnecting the overlapping portions of a binder strap comprising a plurality of interlocking deformations formed along opposite edges of the overlapping portions, the deformations -near the ends of the joint being individually of less magnitude than the deformations nearer the center thereof.

11. A joint for interconnecting overlapping portions of a binder strap comprising a plurality of interlocking deformations formed along an edge of the overlapping portions to interconnect the same, the area: of deformation per unit length of theoverlapping portions being less at the ends of the ovlapping 'portions than intermediate the en 12. A joint for interconnecting overlapping portions of a binder strap comprising a plurality of deformations along opposite edges of the overlapping portions, pairs of said deformations being in transverse alignment and the pairs of deformations adjacent the ends of the overlapping portions being of less magnitude than pairs nearer the center. l

13. Ajoint for interconnecting overlapping portions of a binder strap comprising a larger centralinterlocking deformation, and a small interlocking end deformation adjacent each end of the overlapping portions.

14.A joint for interconnecting overlaplll 16. A joint for interconnecting overlapping portions of a flat binder strap wherein a plurality of interlocking strap deformal tions are distributed longitudinally of the 5 overlapping strap portions, the interlocking intensity of such deformations diminishing from the central region of the overlapping portions toward the ends of such portions whereby the tensile strength of the band rem mains relatively high in the region of the ends of the interlocked overlapping portions thereof.

In witness whereof, I hereunto subscribe my name this 29th day of February, 1928. -JOHN W. LESLIE.

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