US1242325A - Method of making chains. - Google Patents

Description

. F. CRAVEN.

' 0F MAKING CH S.

A |o N FILED uLYl 5.

1,242,325, Patented Oct. 9,1917.

Www.

JAMES F. CBAVEN, 0F PITTSBURGH, PENNSYLVANIA.

METHOD or MAKING .cHAINs specification of Letters raient.

. Patented ect. a, 1era Application led July 14, 1916. Serial N o. 109,264.

This invention relates to a method of making weldless or solid link chains, by forging the same directly from a bar, thereby dispensing with welding operations.

The object of the invention is to provide a method of making chains of the charac-y ter described whereby the metal rod or bar is formed into a chain of weldless links without waste of metal, and whereby all of the operations can be effected by means of strong, simple and durable tools acting transversely to the axis of the bar and simultaneously from opposite sides thereof. A further object of the invention is to provide a method for making chains of thefkind described in which the tools for effecting the successive operations upon the bar to convert it into a finished chain act simultaneously upon successive links, thereby greatly expediting the transformation of the bar into the chain.

The invention comprises the several method steps hereinafter described and claimed.

In the accompanying drawings, Figure 1 j is a diagrammatic view illustrating theman-l lner .of transforming the bar into a cham and showing suitable dies for effecting the several operations; Fig. 2 is a plan view of the bar and chain links shown 4in Fig. 1; Fig.

.3 is a transverse section on the line 3 3, Fig. 1; Fig. fl is a similar section on the line 1 -4, 1; and Fig. 5 is a plan viewv of one of the second set of dies.

In the drawings, 1 represents a suitable bar from which the chain is formed, said bar preferably beingof cruciform cross section, as shown in 4 pairs of oppositely disposed webs :2, 2 and 3, 3. In transforming this bar into a chain of weldless links,vit is subjected t0 the action of sets of oppositely disposed dies or tools acting simultaneously on opposite faces of said bar, and between successive strokes of said dies or tools the bar is rotated on its axis through an angle of 90, whereby the dies act on the bar successively in directions at right angles to each other.

The first set of dies 4 act by pressure ig. 3, having the twov 'against the edges of, oppositely disposed webs of the bar and are so formedas to iny dent said webs and entirely separate the same without removin any of the metal and also to press indentatlons into the core of y the bar, and as shown have the central projecting portions 5 whichengagethe edges of oppositely disposed webs and indent the same, and with curved cavities 6 forwardly and backwardly of the projections 5 and bounded by cheek portions 7 which prevent the metal displaced by the projection 5 from fiowing sidewise. Thecavities 6 are of substantiallythe contour of the end portions 8 .of adjacent'links, so that the action of these dies is to entirely separate thetop and bottom webs of the bar and also to press indentations 9 into the core of the bar, which indentations almost, but not completely,',punc ture the same, leaving only thin web portions 10. The extreme ends of .the projections 5 are preferably slightly wedge shape, as vshown at 11, so as to score the webs 10 at their .central longitudinal lines for guiding the next succeeding set of dies. The effect of the dies 4 is to form the bar into successive portions of approximately the shape of crude links, lwith the metal inclosed by each link quite' thin.

The next set of dies 12 are of substantially the shape shown in Figs. 1,4 and 5, the same having projecting portions 13, that of the 'top die lying 'on one side of the longitudinal line of the bar being formed, and that of the'bottom die lying on the opposite side of said longitudinal line, so thatA said projecting portions will pass each otheras the dies come together, and which projecting portions are pointed .so as to uncture the thin webs 10 inclosed by the link, but without removing any of the metal,'-'said projecting.

portions toward their bases being widened `approximately the form of va chain having.

circular links, but in which said links are still integrally connected by the iin portions 16.

The lin portions 16 are confined or inclosed by the links so that the `are not Wholly exposed, and ILOxmally can e reached opposite sides thereof.

only by tools a plied at an angleof 45 to thel plane of t e connected links. 'llools adapted to act on this connecting iin to sever the same whenthe links are-in normal position are `required to be ofsmall size and therefore are neither strong nor durable. In carryin out my method, after the links are forme by the first two sets of dies t and 12, one of the links 'of the connected series, such as the link 17, is shifted relatively to the link 18, to which it `is connected, in order to expose the fm 16 to the direct action of a large, simple and strong tool. This shifting is accomplished by moving the exposed'linkl? while the reminder of the partially formed links are rmly held in clamps or dies, in a manner to bend or rotate the link 17 around an axis perpendicular to the plane of the link 18, or in other words, twisting the link around its portion 19 which is still integrally attached to the link 18. IThe extent of this rotation maybe varied, but should be not less than 90, and is shown as rotated through considerably more than 90, from the dotted line position to the full line position shown in Fig. 2. In this position the tin .16 connecting` the two links is exposed from above and below,

so that it can be reached by the direct action of a tool working normal to the plane of the bar or chain being formed. This severing tool is shown in the form of a pair of oppositely disposed dies20, which are provided with sharp projecting edges 21, which pinch through said 1in from o posite sides and thus sever the same, the ack of'said projections being slightly concave so as to round the end portion ofthe link 18, and the dies at their forward portions being provided with the grooves 23 which forge the severed fin into the end portion of thev link 18.

As standard chain links are of oblong form and the links have been opened out to substantially circular form by the dies 12, it is desirable to afterward flatten the links. rlhis can be accomplished by providing the dies 20 with grooves 24 which exert pressure upon the link 17 from above and below, and press the same into oblong form.

rllhe dies 4f, 12 and 2O act successively upon di'erent link portions of the partially formed chain, and by direct pressure on .Between each of these operations the bar is rotated on its axis through 90, so that said dies act succes-` sively upon portions of the barat right angles to each other. Since all of these operations are upon successive link portions of the bar and are purely pressing or forging operations upon two opposite sides ofthe bar, it is possible to mount these three sets of dies upon a single die block or head, and in actual practice all of said dies are actuated by a common pressing head and act naeaaas simultaneously upon successive portions of the partially formed bar. By performing -these successive steps simultaneously upon rlhe process is entirely a erging or pressure e operation, and is effected,v as will be observed, wlthout removing or wasting any of y the metal, so that the final `nished chain will be substantially' the same weight asthe bar from which kit is formed.

When the links are twisted or rotated as above described, in order to expose the connecting lin, that portion of the link which is being turned to one side, which threads down through the link to which it is still connected, can, of course, not rotate `and therefore this portion of the link is subjected to twisting or torsional action, which not only a'ects that portion which threads down through the link to which it is still connected, but also extends somewhat around into V4the upper and lower portions of the link.. rl`he subjection of this'portion of the metal to the torsional action increases the tensile strength of the metal, and increases this to the greatest extent at thepoint where the two links connect to each other, that is, the vend portions of the links, and where such links are subjected to the greatest wear and stress and where failure usually occurs. The severing of the connecting fin in the manner described without removing any of the metal also reinforces the'end portions of the links by the fact that the metal of the connecting fin is worked into the end portions of the links.

ln commercially carryin out the method, it will be performed pre erably by automatic machinery in which the bar will be' vfed forward step by step between the successive strokes of the dies, and also rotated to 90 between successive strokes of the dies. The machine will be so constructed that th' unformed bar and partly formed links wil be tightly clamped and rigidly held, so that the metal which is displaced by the pressure of the dies, will be caused to How largely toward the free end, that is, toward the unforrned portion of the bar.

lf necessary the links after being completely severed can be subjected to further die action in order to smooth them up and reduce any irregularities and tins which may remain, but ordinarily this will not be neceslid'hat li claim is 1. The method of making solid or weldless chain, which consists in taking a suitable bar, indenting the sanne on opposite sides by pressure without removing any of the metal to form portions of approximately the shape of chain links, and then puncturing the metal inclosed by the links and opening the same out by pressing the metal sidewise, said indenting and puncturing being effected by lateral pressure in the saine plane.

2. The method of making solid ,or Weldless cha-in, which consists in taking a bar cruciform in cross section, indenting opposite webs by edgewise pressure without removing any of the metal to form portions of approximately the shape of chain links, and then puncturing the metal inclosed by the links and opening the same out by pressing the metal sidewise, said indenting and puncturing being effected by lateral pressure in the same plane.

3. The method of making solid or weldless chain, which consists in taking a suitable bar, indenting the' same on opposite sides by pressure without removing any of the metal to form portions of approximately .the shape of chain links, then puncturing the metal inclosed by the links and opening the same out by pressing the metal si-dewise, then shifting two successive links relative to each other around an axis transverse to the bar to expose the connecting fin. and finally severing said fin to separate said links.

4. The method of making solid or weldless chain, which consists in taking a suitable bar and indenting the same from opposite sides by pressure without removing any of the metal to form portions of approximatelythe shape of chain links. then punc-v turing by pressing aside the metal inclosed by said links and opening the links out into circular form, then shifting two successive links relative to each other around an axis transverse to the bar to expose the connecting fin, and finally severing sid fin to separate said links and simultaneously flatten said circular link to oblong form. l

5. The method of making solid or weldless chain, which consists in taking a suitable bar, indenting the same on opposite sides by pressure without removing any of the metal to form portions of approximately the shape of chain links. then puncturing the metal inclosed by the links and' opening the same out by pressing the metal sidewise, and finally separating adjacent links. said indenting, puncturing and separating operations being effected by lateral pressure in the same plane.

6. The method of making solid or weldless chain. which consists in taking a suitable bar, indenting the same from opposite sides by pressure without removing'the metal to form portions of approximately the shape of chain links, then puncturing and opening out the vlinks by pressing aside the metal inclosed thereby, then shifting two successive links'relative to each other around an axis transverse to the bar to expose the connecty ing fin, and finally severing said fin to separate said links` said indenting, said puncturing and opening out and said severing of the fin being performed simultaneously upon successive' link portions by pressure in the same plane.

7. The method of making solid or Weldless chain, which consists in taking a bar cruciform in cross section, indenting opposite'webs by edgewise pressure without removing any of the metal to form portions of approximately the shape of chain links, then puncturing the metal inclosed by the links and opening the same out by pressing the metal sidei'vise, then shifting two successive links relative to each other around an axis transverse to the bar to expose the connecting fin, and finally severingsaid fin to separate said links.

S. The. method of making solid or weldless chain. which consists in taking a bar cruciform in cross section and indenting opposite webs by edgewise pressure without removing any of the metal to form portions of approximately the shape of chain links, then puncturing by pressing aside the metal inclosed by said links and opening the links out into circular form. then shifting two successive links relative to each other around an axis .transverse to the bar lto expose the connecting fin. and finally severing said fin to separate said links and simultaneously Hatten said circular link to oblong form.

9. The method of making solid or weldless chain, which consists in taking a bar eruciform in cross section, indenting opposite webs by edgewise pressure without removing the metal to form portions of approximately the shape of chain links, then puncturing and-opening out the links by pressing aside the metal inclosed thereby, then shifting two successive links relative to each other around an axis transverse to the bar to expose the connecting fin, and

finally severing said fin to separate said

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