US1581794A - Process of and apparatus for forming wire ties - Google Patents

Description

April 20 1926. 1,581,794

H. DE HAVEN, JR

1 June 15, 1921 Patented Apr. 20, 1926.

UNITED STA TE PATENT or FICE.

' I HUGH DE HAVEN, JR., OF SAN FRANCISCO, CALIFORNIA, 'ASSIGNOR TO '.l II-IT MA- CHINE COMPANY, OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF CALI- FORNIA.

PROCESS OF ,AND APPARATUS FOR FORMING 'WIRE TIES.

Application filed June 15, 1921. SeriaLNo. 477,645.

To all whom it may concern:

Be it known that I, HUGH of the city and county of San Francisco, State of California, have invented a certain new and useful Process of and Apparatus for Forming Wire Ties, of'whichthe following is a specification.

The invention relates to the art securing together wires or the ends of a strand. of wire which is placed around a package for protecting the package during shipment and relates particularly to the art of twist-- ing together the ends of a strand of wire which has beendrawn taut around aj box, or twisting together two wires. i

lln the art of securing wires around boxes, the procedure has been to pass a wire around the box, draw the wire tight and then twist the ends of the wire together to form a .tie or look. The desired end to-be accomplished is to form a tie or lock which will withstand as great if not a greater strain than the wire and it has usually been considered desirable to form a tie which will hold under a tension sufliciently great 'to rupture the wire. Attempts to reach this desired end have not culminated in uniformly successful results. The two ends of the wire strand have been twisted together a plurality of times, but it' has been found that when the ends were twisted together that the wire was weakened at the twist during the twisting operation, so that when tension was later placed onthe wire, it broke at the twist. Devices for twisting together the ends of a wire strand surrounding a package are usually manually operated and the twist that they are designed to produce should be of such form that the device can be easily operated by one man. The twist which can be formed most satisfactorily by a hand-operated device, is a double twist, that is, a twist formed by the rotation of a twisting element through two complete revolutions. Great diificulty has been experienced in the past in producing a satisfactor double twist, since if the twist is formed oosely it will unravel under ten sion and if formed too tightly, the wire is so weakened durin the twisting operation, that the twist will rupture under tension. To overcome this difficulty, it has been proposed to form the tie of three twists, produced by the rotation of the twisting ele- De HAvnnf, J r., \rnent through three complete revolutions. a citizen of the United States, and a resident This, however, in a hand machine requires the use of a long, unwieldy operating lever oi'flof' a crank, either of which is objectiona e.

In accordance with my invention, I have provided a double twist tie, or as it is termed n the art, a two-twist tie, which has a holding power not less than the tensile strength .of the wire and which is so formed that the a greater number of twists. l have formed two-twist ties using No. 13 gauge baling wire and have found that the tiss so formed are of uniformly greater tensile strength than the wire. I have found that it is not necessarily the number of twists which determines the efiectiveness of the tie, but rather the form of the twist and after a careful analysis of the problem I have produced the very efiicient twist of the present application. a

An object of my invention, therefore, is to produce a wire tie, preferably of the twotwist type, wherein the twists are so formed that the tie has a tensile strength equal to or greater than the wire and in which the wire is not weakened so that under tension it will not break or unravel at the twist.

A further object of the invention is to provide a process of twisting the ends of a wire, or wires, together so that the above desirable results will be obtained.

A further object of the invention is to provide an apparatus for forming the desired twist.

The invention possesses other advantageous features, some of which, with the foregoing, will be set forth at length in the following description, where I shall outline in. full the twist of my invention, the method of forming the twist'and one form of apparatus for forming it. In the accompanying drawings I have shown one form of twist of my invention and the apparatus for forming it, but it is to be understood that I do not limit myself to such form of twist or apparatus, since the invention, as set forth in the Claims may be embodied in a plurality of forms. 1

Referring to said drawings:

Figure 1 is an elevation, somewhat diagrammatic, of the twisting gear heretofore generally employed, showing a twisted tie therein. 1

Fig. 2 is an elevation of one form of twisting gear of my invention.

Fig. 3 is an elevation of another form of. twisting gear of my invention.

Fig. 4 is a side elevation of the twisting gear shown in Fig. 3, with a portion of its cooperating driving gear.

Fig. 5 is a side elevation of a twisted tic formed in the gear shown in Fig. 3.

Fig. 6 is a plan. of the twisted tie shown in Fig. 5.

In tying la wire'on a package, the usual procedure comprises passing the wire around the package and disposing the overlapping ends of the wire in close relation in a 1'0- tatable twisting element and in guides or holding members flanking the twisting element. The guides usually comprise blocks having alined slots therein, of a height sufficient to receive the wire, but not suflicient to permit the wires to move bodily during the twisting operation. The guides, therefore, serve the function of preventing the wires from twisting over each other, so that the twist' is confined between the guides. Disposed between the guides is the rotatable twisting element which is provided with a slot in which the overlapping wires are disposed. The slot is usually narrower at the center, its height at that point being substantially the sameas the slots in the guides and for. the same. purpose. At both ends, the slot in the rotatable twisting member is increased in height to provide space wherein the twist may form. Prior to the twisting operation, the wire is drawn taut around the package, so that the wire ends lie in substantially parallel relationship in the grooves in the guides and twisting member. One form of assembled mechanism for forming twisted wire ties is shown in the co-pending application of myself and O. L. Drew, Serial No. 414,108, filed October 1, 1920, to which reference is hereby made for a disclosure of a complete wire tying device. The present invention, however, is not in any manner limited to the showing made in such application, since the tie of the present invention may be formed in devices of different structure, and since the tie may be used for other purposes, such as for securing togethertwo wires.

The twisting element usually comprises a go. 1' 2 having integral stub shafts 3, suitably journaled in pillow blocks 4, and engaged by a driving gear 5. The gear unit, consisting of the gear and the stub shafts, is rovided with a longitudinal slot 6 exten ing radially from the periphery, to and slightly beyond the rotational axis. The depth of the slot is preferably such that when two wires are disposed longitudinally in the slot in close relation, as shown in Fig. 4, the wires lie close to or on opposite sides of the axis of rotation. At its central portion the slot is of just sufficient height to rea'tlily receive a wire, so that as the gear is rotated the wires at the narrow portion are incapable of relative bodily movement. At the opposite ends, the slot is increased in height, to form two chambers 8 and 9 in which the twist is formed. The widening of the slot produces shoulders 12 and 13 at opposite ends of the gear unit, which serve as anvils against which the wire is bent as the gear unit rotates. It has been the practice heretofore, to position these shoulders 12 and 13 di rectly opposite each other, as shown in Fig. 1, with the result that as the gear is rotated both wires of the twist start to bend at the same point longitudinally of the twist. One wire bends u wardly, crossin .over the other wire, and being forced there y against the upper shoulder 12 with great pressure, and.

the other wire bends downwardly, crossing under the other wire and being forced thereby against the lowershoulder 13 with great pressure, the pressures being the bending pressure of the wire and the additional pressure caused by the opposing pressure of the other wire. The wires are not only subjected to pressure and torsion, but since they move laterally in twisting, the shoulders produce a shearing strain. These effects cause the shoulders to bite sharply into the two wires, weakening the wires and consequently weakening the ultimate twist By virtue of this construction, also, the convolutions of both i wires, forming the twist, are uniformly axi' all displaced with relation to the longitudina axis through the gear unit, and experience has proven that upon subjecting such twist to tension, it will often pull apart orunravel, without breakingthe wire. Such twist as that shown in Fig. 1 does not possess a tensile strength equal to or greater than the wire and w en subjected to tension will either rupture at the point of beginning of the twist, where the shoulders have mutilated the wire, or will pull a art, and either of these conditions will usua ly occur before sufiicient strain has been placed on the wire to rupture it at an untwisted portion. If the twist is formed tightly, the biting action of the shoulders will materially weaken the wires and if it is formed loosely it will unravel under tension.

;1 -In accordance with my invention, I. form the twist in such manner that the beginning of the twist in one wire is spaced longitudinally from the beginning of the twist in the 7 other wire so that the injurious biting action of the shoulders against the wire is obviated, and so dispose the convolutions of the twist, I that when strained the full convolutions of each wire pull directly againsteach other. In the construction of. gear unit shown in Fig. 2, the upper shoulders 12 are spaced apart a greater distance than the lower, shoulders 13, so that one wire starts to bend at the shoulder 13- whereas the other wire starts to bend at the shoulder 12, so that the injurious effect of the shoulders on the wire is minimized.

Substantially the same result isobtained with the form of gear unit shown in Fig. 3, wherein only one shoulder 12 and one shoulder 13 is employed, the faces of the slot opposite the shoulders being referably smooth and unbroken. The shoul ers are preferably slightly beveled, as shown at 15, to further lessen the biting eifect on the wire. By this arrangement of the shoulders, one twist forming chamber 8 is disposed partly above the axis of the gear unit and the other twist forming chamber 9 is disposed partly below the axis, so that the twists are displaced oppositely with relation to the axis of the gear unit and with relation to the untwisted central portion of the tie. Instead of both wires being pressed against shoulders at both sides of the untwisted central portion, only one wire is pressed against a shoulder and the other wire bears or wears against a smooth surface. I have found that the tie formed by the gear unit shown in Fig. 3 is somewhat preferable to the tie formed by the gear unit shown in Fig. 2, although the tie formed by the gear unit shown in Fig. 2 is preferable to the tie formed by the gear unit shown in Fig. 1.

In Figs. 5 and 6, T have shown the twist as formed by the gear unit shown in Fig. 3. The two ends 16 and 16 of the wire are disposed in overlapping relation and twisted, as heretofore set forth, forming a central untwisted portion flanked by the twisted portions 17 and 18. lln forming the particular twist shown, the gear unit is rotated through two complete revolutions, forming a double twist on each side of the central untwisted portion. In the drawings, I have shaded the two wires-16 and 16 difierently so that they may be readily identified in the twist. In order to produce a tie having the desired qualities, T find it advisable to form the twist in such manner that the initial points of bending of the two wires be spaced apart longitudinally. Referring to the twist 17, it will be seen that the wire 16 departs from the straight or untwisted portion at the point B and that the wire 16 departs from the untwisted portion at the point C and that ,the'points B and C are spaced longitudinally of the tie. The wire 16 bends over the shoulder in the twisting element while wire 16 wearing against a smooth supporting surface forces wire 16 over'it, axially displacing the twist from the axis of the rotating center section. It will be seen that wire 16 cannot crowd into the initial twisting point B of wire 16 and,

therefore, is compelled to begin its twist fronrnnother point C. The same conditions .Qbtain in the twist 18 wherein the wire 16 starts bending at D and the wire 16 starts bending'at E. In the twist 18 (see Fig. 5)

the wires in the convolutions are completely disposed below the plane of the uppersurface of the central untwisted wire and in the twist 17 the wires in the convolutions are completely disposed above the lower surface of the wire in the untwisted central portion.

strain is placed principally on the wire 16 v in the twist 17 and the wire 16' in the twist 18 tending to straighten these wires, and a lesser straightening strain is placed on the wire 16 in twist 17 and on the wire 16 in twist 18. The humps 23 and 27, therefore, are maintained in form and form abutments against which the abnormal humps 21 and 25 are pulled. This produces a tie which has a greater tensile strength than the untwisted wire, due both to the shape of the twist and the fact that the wires are not weakened by being cut into by shoulders on the twisting element. While I have shown two forms of twisting elements which may be employed to produce the tie of my inven tion, it is to be understood that other devices may be used for producing the tie and that the tie is not limited in its formation to any particular form of apparatus, nor to any form of use or application, nor to any specific number of twists, although for band formed ties, the double or two revolution twist is preferable.

ll claim:

1. The method of securing wires together, which comprises disposing said wires in overlapping relation, holding said overlapping wires at spaced points, rotating the two wires bodily intermediate said held portions whereby two twists are produced and forming said twists so that one twist is disposed wholly below the upper surface of the wire at the intermediate untwisted portion and the other twist is disposed wholly above the lower surface of the wire at the intermediate untwisted portion.

2. The method of securing wires together, which comprises disposing said wires in overlapping relation, holding said overlapping wires at spaced points, rotating the two wires bodily intermediate said held portions whereby two twists are produced separated by an intermediate untwisted portion and controlling the wires at the junctures of the twists with the untwisted portion so that the points of initial bending of the wires at the juncture of a twist and the untwisted portion are spaced apart longitudinally.

3. The method of securing wires together,

I which comprises disposing said wires in overlapping relation, holding said overlapping wires at spaced points, rotating the two wires bodily intermediate said'held portions whereby the wires are twisted together twist to bend over a shoulder and the other wire to bend over said first wire.

4. In a wire tying machine, a rotary Wire twisting member, having a longitudinal slot therein adapted to receive the wires to be twisted, one face of said slot being depressed adjacent one end of the member and the other face of. the slot being depressed adj acent the other end of the member, the surfaces of the slot being otherwise unbroken.

In testimony whereof, I have hereunto set my hand.

between the intermediate portion and the held portions, andeausing one wire in each HUGH DE HAVEN, JR.

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