US2796783A - Metal band forming tool - Google Patents

Description

June 1957 R. w. DANIELS METAL BAND FORMING TOOL Filed July 16, 1954 INVENTOR.

Paw/v90 14 pflN/fli 9 M Q/[W United States This invention may be manufactured and used by or for the Government of the United States of America for governmental purposes without payment of any royalties thereon or therefor.

This invention relates to metal working tools and more particularly to a banding tool for forming strap brackets.

Of the various types of brackets used to support elec trical cables, pipes, etc., to wall structures, one of the more common is the type formed of a metal-attaching strap that has a free end provided with a U-shaped loop, the loop engaging the cable to be banded and being clamped in position by a transverse nut and bolt extending through its legs. While this type of bracket is generally accepted, it has several disadvantages, among which is the comparatively long time required to complete the assembly, as well as the fact that, when the bracket is used to ground R. F. armored cables, the uncovered portion of the cable adjacent the bolt causes a high resistance to ground.

To overcome these disadvantages, several commercially available banding tools have been tried, but, although these have some remedial effect, they, nevertheless, produce such a sharp bend in the strap at the juncture of the band as to form a most undesirable weak point which, in cases where the strap is secured to a support that is subject to heavy vibrations or shocks frequently produce breakage.

Accordingly, a principal object of this invention is to provide a strap bracket capable of resisting shock and safely absorbing any vibration to which the mounted bracket may be subjected. A

A further object is to provide such a bracket which is easy to assemble and designed to engage the entire circumference of Armor cables to ground any R. F. currents.

Still other objects are to adapt commercially available banding tools for accomplishing the purposes of the above objects and to adapt these tools in such a manner that the tool can be easily and quickly modified for accomplishing either its designed purpose or that of the present invention.

In accordance with these objects, the invention, in one of its preferred forms may be embodied in a specially adapted tool for use with the Punch Lok banding tool disclosed in Patent No. 2,312,400, although, as will become obvious, the attachment may be used for other types of banding tools or a new tool can be constructed to incorporate the features to be discussed. To accommodate this particular banding tool the attachment is formed with a body having a pair of cars between which the front end of the tool is attached and this body is provided with a forwardly extending lip over which the banding material may be advanced. The lip, in turn, has a rounded end that functions as an anvil first to press the band around the cable to permit tensioning, and thereafter to form the strap loop. The loop is formed by pivoting or swinging the anvil portion and weaknesses are avoided by assuring that the diameter of the rounded lip end is substantially greater than the thickness of the banding material. The bend then becomes one of a suflicient diameter to absorb any shock to which the bracket may be subjected, the diameter of the loop, of course, varying directly with the weight of the cable.

One embodiment of the invention is illustrated inthe accompanying drawing, of which Fig. 1 is a side elevation of a conventional banding tool; Fig. 2 is a cross section of a cable and attaching strap formed by the conventional tool of Fig. 1; Fig. 3 is a partial side elevation showing the attachment of this invention mounted on the Fig. 1 tool; Fig. 4 is a perspective of the loopforming anvil; Fig. 5 a view similar to that of Fig. 2 showing the attachment forming a vibration loop in the strap, and Fig. 6 an elevation showing the completed strap bracket of Fig. 5 supporting the cable on a wall.

Referring to the drawings, the conventional tool shown in Fig. 1 is one of the type commonly used for strapping various objects, such as bales, hoses and the like, one end of the banding strip band usually being anchored to a connecting member through which the free end is passed to form a band which the tool tensions about the object. As previously indicated this Fig. 1 tool is functionally representative of a commercially available tool described inPatent No. 2,312,400, and as such it simply exemplifies one of a number of tools on which the attachment of this invention may be used.

Before describing the improvements of the present invention it might be well to understand the construction and operation of this conventional tool shown in Fig. 1. Referring then to this figure it will be seen that the tool, generally indicated by numeral 2, is formed with a support 4 having a rearwardly-extending integral rod or lever 6 terminating in a handle 8 by which the tool is braced. Support 4, in turn, is channelled to house a gripping jaw 10 pivotable on pin 11, as well as an independently pivotable clevis 12, this latter member mounting a springbacked lever 14. A channelled block 16 houses another pivotable jaw 18 slidably mounted on rod 6 and operatively connected to clevis 12 by a link 20. Banding material 22 is threaded through support 4 and block 16 to the extent that actuation of lever 14 toward handle 8 causes jaw 18 to move the band rearwardly of the support for a length depending on the stroke of block 16. On the other hand, movement of lever 14 away from handle 8 returns block 16 back to its starting position (illustrated in Fig. 1) for the next tensioning stroke. Thus, it is noted that gripping jaw 18 has a ratchet action to move the banding material on the rearward stroke of block 16 but to pass freely over the banding material on the forward, return stroke. Gripping jaw 10 has a similar ratchet action in that it permits the tool to be moved forward by the tensioning of the banding material but will prevent the backing ofl of the tool. Gripping jaw 10 may be released by the operator to permit the tool to be backed off by pushing lever 14 until the end abuts the opposite side 21 of gripping jaw 10.

In Fig. 2 is shown a strap 24 having a band 26 being tightened around a cable 28 by use of banding tool 2 without the attachment of this invention. It can be noticed that the front fiat face of support 4 abuts the connecting member 30 of the band during the tightening op eration and forms a sharp bend 32 in the strapadjacent the junction of the band. When such a strap has its attach-ing end 33 secured to a support that is subjected to excessive vibration or shock, it obviously will break at its weakest point which is the sharp bend 32 developed in above manner. For this reason these banding tools, although otherwise unusually efiicient and expeditious, have been unsatisfactory for the presently contemplated purposes.

Figures 3 to 5 illustrate an attachment 34 by means 3 of which the sharp bends in the strap are eliminated to make possible the otherwise unsatisfactory use of banding tools. Furthermore, the attaching end of the strap may be worked into a U-position in; the same operation to be ready for mounting to the support As shown in these figures, attachment 34 comprises a body or frame 36 having a pair of lugs or ears 38 spaced apart to accommodate the front end of tool support 4, the ears being provided with aligned apertures 40 to receive the grip ping jaw pin 11 for securing the attachment to the tool. Obviously this means for securing "the attachment to the tool will vary in details depending on the particular banding tool being used. A lip '42 is integrally formed on frame 36, and projects forwardly of the tool in contiguous relation to channel base 43 of the frame to support the banding material as it passes through thetool. The lip, further, is provided with a rounded anvil end 44 that functions to form a vibration loop 46 in the banding material. In forming the loop, it is important that the diameter of the anvil end 44 be large as compared to the thickness of the banding material to assure that the loop is adequate. For example, with a banding material of galvanized mild steel, the diameter of anvil end 44 should be at least 4 times the thickness of the material, while, for stainless steel banding material, the :diameter of the anvil end should be at least 8 times the thickness of the material.

The operation of loop-forming attachment 34 is illustrated in Fig. where a strap 48 of banding material 22 is formed into a band 50 to encircle an Armored cable 28. In making the loop, its attaching end 52 first is tensioned by the banding tool With anvil lip 42 engaging the band. Preferably the anvil is engaged with a connecting member 54, the tool being held in the dashed line position of Fig. 5, and, to form vibration loop 46, the tool then is pivoted toward the band into the illus trated solid line position. After the tool is removed, attaching end 52 of the strap may be cut to the desired length necessary for securing the cable in a supported position on a wall 56 as shown in Fig. 6. As described, vibration loop 46 absorbs any vibration on a strap caused by shocks and prevents damage to the strap. 7

By use of the loop-forming attachment of this invention a conventional banding tool may be utilized to construct strap brackets in a manner that is capable of ab sorbing vibrations. It is obvious that the attachment may be formed as a permanent part of the tool or made as a detachable attachment as illustrated to permit the banda 2,796,783 I r ing tool to be used for other strapping operation, and the facility by which the conventional tools can be adapt ed for either use also prevents a most desirable asset.

Obviously, many modifications and variations of the present invention are possible in the light of the above teachings. It is, therefore, to be understood that within the scope of (the appended claims the invention may be t practiced otherwise than as specifically described.

I claim:

1. A banding tool attachment for forming a loop in a banding material comprising a frame having a front wall and a pair of laterally spaced ears adapted to straddle the forward end of a tool and be detachably secured thereto, said front wall having an opening for the passage of the banding material, said frame having a forwardly extending lip terminating in a rounded free end about which the banding material may be bent to form a compression loop.

2. A banding tool attachment for forming a loop in a banding material comprising a frame having a fiat base, lug means projecting outwardly from said base and provided with means permitting detachable securement of the attachment to the tool, said lug means being :carried at the rear portion of said base whereby said rear portion is securable to the front portion of the tool in a position permitting the forward end of said base to project forwardly of the tool as an extending lip, and said lip being provided with a rounded end portion having a radius of curvature substantially greater than the thickness of the heaviest banding material normally worked by the tool, whereby said tool and attachment are adapted to form such a relatively wide loop in the banding material as can be safely compressed when subjected to shock.

References Cited in the file of this patent UNITED STATES PATENTS 971,291 Marden Sept. 27, 1910 1,347,579 Henrikson July 27, 1920 1,512,014- Bryar Oct. 21, 1924 1,766,577 Willing June 24, 1930 2,102,900 Kankel Dec. 21, 1937 2,150,234 McKee Mar. 14, 1939 2,208,134 McAneny July 16, 1940 2,334,637 McKee Nov. 16, 1943 2,466,912 Rice Apr. 12, 1949 2,513,438 Weir July 4, 1950

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