US1768832A - Process of chain manufacture - Google Patents

Description

July 1, 1930. R. w.` DULL PROCESS OF CHAIN MANUFACTURE Filed May4 7, 1924 3 Sheets-Sheet l AttOWQ/yJS.

July l, 1930.

Rl w. DU| L PROCESS OF CHAIN MANUFACTURE 3 Sheets-Shet 3 Filed May '7, 1924 Patented July 1, 1930 .narran stares e intern rar-ENT oFfFicr;

RAYMOND W. DULL, OF CHICAGO, ILLINOIS, ASSIGNOR TO LINK-BELT COMPANY, OF

CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS Pizocnss or cnam Menusncrunn Application led May 7; 1924. Serial No. 711,533.

My invention relates to a process of making chain from a strip of sheet metal stock, and particularly to a process of continuously making the links and automatically assembling the links as they are made into the completed chain. The general object oi' my invention is to produce chainot the type herein described; in lwhich hook and vpintle tongues are stamped from the center 1o of the link blank and the hook and pintle end bars are bent to producea chain7 each link of Which consists of flat side bars, a relatively cylindrical hook at one end and a pintle at the other end, shaped'for rotation Within the hook of the link next adjacent. One object is to provide a process for manufacturing chain of the type described, with maximum cheapness and simplicity. Another object is to provide a process for the production of such chain in Which the hook and pintle tongues are stamped from the center of the blank and curled into tinished hooks and pintles with a -minimum strain upon the metal of the blank and a minimum weakening and distortion of the fibers of the metal. Another object is the provision of a process of scoring or indenting the individual blanks in order to reduce to a minimum the tendency of the end bar to tear out. Other objects will appear from time to time in the course of the specication e and claims.

l illustrate my invention more or less diagrammatically in the accompanying drawings, wherein- Figure l is a plan View of the strip of material operated upon; illustrating the eftectot the successive die impacts;

Figure 2 is a section along the line 2 2 of Figure l; f

Figure 3 is a plan view similar to Figure l, but showing the under side of the stock;

Figure d is a skeleton side elevation of the punch and die, illustrating the passage of the stock therethrough, and vits .formation into links;

Figure 5 is a View of a rounded punch which may be substituted for the pointed punches shown in Figure 4; and

Figure 6 is a longitudinal vertical section through aslightly modilied form of punch and die; l

Figure 7 is a plan View of the die structure. f Y Y l p l Like partsare illustrated by like characters throughout the specification and drawings.

A is any suitable base having mounted thereupon the die block A1 which may be secured thereto in any suitable fashion.

B is any suitable strip of relatively resistant material upon which rests the individual die elements. These elements are gripped and aligned in any suitable manner and will later be discussed in detail.

rlhe passage of the metal strip C over the die block is from right to left, as shown in Figure 4. This ribbon or strip of stock C may be'initially straightened and fed by any suitable means not herein shown, being guided into the machine for example by the yieldingly mounted supporting block C1, Which is mounted to reciprocate vertically in the die block A1, being supported; for example by the spiral spring C2, its vertical movement being limited in any suitable yfashion. C5 is a centrally disposed iiat bearing surface thereon, adapted to receive the bottom of the strip C and upon Which the strip may be centered, for example by a pair 01" opposed set screws CG, which may be adjusted to adjust the strip C laterally.

D is a second strip or stock supporting yoke or block slidable along vertical pins D2 and upwardly pressed by the spiral springs D3 against the heads D4 of the pins.

P, P are conical prick punch elements mounted in the yoke D, the purpose of which Will'be later described.

Positioned to the left of the support D, as shown in Figure 4, are a pair of opposed strip or stock guiding elements E adapted to reciprocate in the apertures El in the block A1, the lower portion of each serving as a plunger to guide this reciprocation They are normally maintained in a position of maximum elevation by the coiled springs E5 Which penetrate the cylindricalapertures E@ in the guide elements. The upper por- Ytrion ofv the guide elements are laterally inwardly slotted to engage the edge of the stock or strip which may be centered between the opposed guides, for example by the set screws E"a k u is. astocv V,en agingelement havin a pair of` ilpii'ardly rojecting, longitudinglly extending iugs G1, Gl adapted to engage the side bars of the lilik blank. It rests upon the tops of a pair of plungers G2, the lower extremities of which are fixed in a yoke Gr8 slidable along the pin G4. Gr"I ris a spiral spring compressed between the yoke G3 and the stock G adjacent the lower extremityof the pin. G7, G7 are adjusting nuts screw threaded upon the lower portion Gs of the in. i y y Mounted still farther tothe left, as shown in Figure 4, are a pair of opposed channel ironhguides H, H, adaptedto engage the o posite sides of the chain links. `Any suita e means may be provided for drawing them forwardly therealong, said means being not shown herein, and forming no part of the invention,u claimedv in ,the present application,l The channels H are connecte' for example, by cross pieces H1, the ends of whichare perforated to slide upon tllegpairs of vertical guides H2, and are kept normally in raised position, as shown in Figure ,4 by the spiralqspringsyH?. The heads Hi of the `pins serve, as stops to limit the upward movement of the crosspiece H1.

The chain formedvby the passage between the opposed die and punch elements of a strip of stock which is moved forwardly therebetweenby a step by step movement, bywany suitablefeeding means, the details (if whichneed not be shown herein. At ea vh successive vforward movement the punch e ementdis moved downwardly againstv the die element byy any suitable press mechanism. The punch block K is clamped into any suit;- ablelworki backing Kt, for example by the set Screws ll. K7 is a backing or base element similar to the backing orbase B of the Vdie block, and ada ted to engage the inner endswof the indivi( ual punch elements. MThe unch and die elements are for` purposes oA description arbitrarily grouped into the membersor areas operating simultaneously upon the link blank as it passes step by `step therebetweem and will be described in relation to the impression they successively make upon the blank. As the stock C is assed lforwardly through the guide C1 it is :t engaged by opposed indented or striated gripping pads L, L1, L being fixed in relationy to the die block A1, L1 being yieldmounted in the punch block K, and hield in normally downwardly extende po'siti'o .for example, by the spiral spring L The unctionof the opposed pads is to grip thestock and prevent lateral movement thereof during and in response to the successive forming impacts, their action being particularly important when the strip is first fed through between the punch and die and before its end has reached the opposite end of the die. The pads ma be of metal, orrof any suitable fibrous or rictionf length of one chain link blank, and is then 'Y subjected to the action of a pair of prick punches L2, L2 on the die, and a transverse scoring knife L3 on the punch. ri`he prick piiiich elements are so positioned as to indent the inner corncrsof the junctions .y

between lthe side barsand the pintel 'en-d bar, en the'iowerI side of the stock along the line of future division between the tongueshwhicli will ultimately be separated fromtheside bar to form the hoo pintle ofthe lcomp eted link.

44WhereasIH prefer to use sharp pointed prick puncheshit will be understood hat undery some ircumstances a rounded or lall tippedpuncib or indentinl instrument can be/,substituted which wil have the saine function and perform the same service. The alternativetype of prick punch is illustrated as P in Figure `5. e I

the next forward Amovement of the sto "Y they blank or future link is so ositionedthat transverse severing kni e L5 oyerlies the score Z3 and severs the metal therealonff, cuttin apart the edges of the o posed, fook an pmtle tongues, bending t e pinte tongue` downwardly about the Eend LMand slightl bending the end of the ook tongue and 4eginning its separation from `the side bars, as shown in Figure 2.

Meanwhile, the yopposedpairs of longitudinal scoringknives L, LT score or outline the unsevered or uncut edge of the hook tongue on vthe top and bottom of the stock respectively, as shown at Z7 in Figure 1 and Z in Fi ure. 3. n u b At t e next forward movement of the stock it passes above the yielding block D, above described, and the bottom ofthe stock is punched by the prick punch elements D thereupon, the prick punch marks coming at thecnds of the bottom longitudinal scores l and indicating the inner corners of the junction between the side bars and the hook end bar of the link. The punch inarkfs'sbve to prevent tearing out of the stock when the hook tongue is severed from the side bars along the longitudinal scores l", Z7.

The knife L1l further bends the ends'of the pintle and hook tongjies, thel eiidbf tlie plintle tongue being bent about the beading e l" and the end of the hook tongue being rolled about tl'ie rounded corner L1* of the yieldingly mounted block D. The hook tongue is thereby separated from the side and i Cru bars along part of the length of the longitudinal scores l, Z7.

At the next forward movement kof the stock the punch element L16 completes the separation of the hook tongue from the side bars, moving it to the position shown at X15 in Figure 2, the punch marks llo preventing tearing away of the hook tongue at the corners. Meanwhile the transverse` scoring knife L20 deeply scores theV top of the stock, outlining the separation between adjacent links, and the end of the punch element L16 further slightly bends the pintle tongue about the transverse bead L18, along the left l edge of theblock D, as shown in Figure 4.

At the next forward movement of the stock the punch element M which has substantially the cross section of the central aperture of the link, punches out or moves -v the hook tongue to the position shown at m1 in Figure 2. Along the base of the punch M are the inclined punch ledges l 2 adapted to engage the side bars of the link and bend them into the position shown at m3 in Figure 2. The rounded ends M4, M5 of the base of the punch block M, operating against corresponding die elements, bend the hook and pintle end bars respectively of the link to the form shown at m5, m7 in Figure 2.

T he punch M near the pintle end is slightly wider, as at M9 than the central aperture of the link, and chisels out a part of the aperture to allow freedom for the hook in the finished chain.

Finally at the next movement of the stock the cutting edge N, formed by a downward off-setting of the punch, shears along the score 220 and against the opposed cutting edge N1 of the die, and severs the partly completed link from the stock. As the stock is forced down bythe punch, prior to the severing, the side bars of the linkare engaged by the longitudinal lugs G1 of the yieldingly mounted block G, and are locked thereby against the punch element N2, which is provided with a central portion N3 penetrating within the central aperture of the link, and side bearing surfaces N4D in opposition to the tops of the lugs G1. The severed link is thus firmly gripped, the spring G5 serving to compress the block G and the lugs Gl against the link, and to lock the link against the punch N2.

The curved portions N5, N6 of the punch i" N2 engage respectively the bent hook and pintle end bars. As the link is carried downwardly by the punch, the end of the hook tongue engages the rolling die surface 1 N5 and is curved thereby into the position N7, as shown in Figure 4. Prior to the com- `pletion of this rolling movement the pintle tongue contacts the die surface NS and is bent into the position shown in Figure 4;. The rolling movement of the hook tongue is shown at O in Figure 4. The hook tongue t curls around and incloses it, thus fastening thenewly formed link to the end of the completed chain, as shown in dotted lines at O1 in Figure A.

The guides H and the completed chain y travelling therethrough are normally maintained in general alignment, as in Figure l, with the stock as it passes throuoh the yieldingly supported guide elements (ril and E. As the stock is depressed by the action of the punch elements thereupon, the punch also contacts the cross elements H1, and depresses the finished chain, maintaining it in alignment with the stock as it descends and with the descending severedlink as it continues its descent following severance from the stock. As the hook tongue of the link begins to curl, as at N7, the pintle bar of the finished link is dropped into position in the bend of the hook tongue and is thus sur- .7;

roundedby it as the hook tongue is rolled into final position. At the next forward movement of the stock and the completed chain, the completed link is drawn forward with the completed pintle bar ready l quent breaking down and weakening of its I structure, I provide at eaclr side of the scoring knife T the depressions T1, T1. The scoring or creasing knife T2 serves to crease the bottom of the stock along the inside of the bend of the future pintle tongue. The prick punch elements L2 are shown as moved forward one step to Voccupy the position of the pad L in Figure e, and the pad L may be moved forward, or may, if desired, be dispensed with.

The use and operation of my invention are as follows: j

I manufacture chain from a ribbon or strip of sheet metal stock which is fed forwardly step by step between opposed punches Y and dies. The interval between the forward feeding movement needv be only suiiicient to permit the strip to move forwardly through the press the length of one link.

In order to prevent interference between the stock and tlie punch or die, at the time of Stich forward iriov'einent, I provide means for lifting the enen-e snip of stock from the die between the forming impacts of `punch upon die. In the form herein shown,

move the strip upwardly, after each impact, to a. position substantially midway beween puneh and die when the punch is `i'ivithdravvn to its maximum Height. In the illustrated mechanism, I accomplish this re- 'siit by feeding tlie strip forwardly through yieldingly mounted guides which are adapted normally to su )port the stock a predetermined distance .f ove the dies, but which ermit it to descend, and descend with it, in response to the action of the punch. As the punch descends, it forces the strip and with it the strip guides downwardly toward the die block, and as soon as the punch withdraws, the guides rise and carry the strip with them. I center the strip in relation to die and punch by means of setscrewsor other adjusting mechanisms on the yieldin ly mounted guides or supports.

n the form of punch and die herein shown, the portions which are forced out of the normal plane of the strip are allbent downwardly toward the die. It is there- 'fore necessary to lift the strip above the `die a distance greater than the length of the lar est downward projection, namely the hoo tongue. In the method of forming chain herein described, the side bars of the chain are not deformed or bent until shortly before the link is severed from the chain stock. Therefore the stock throughout most of its excursion between the punch and die has straight edges, and can easily and eiliciently be fed forwardly through the guides.

The stri metal stock, of which the links are forme is a. fibrous material, and of course tough and hard. In making links from it it is necessary not only to render easy the severingof the parts which have to be severed, and to make this severing possible without distortion of the stock, but also to limit the severing and to counteract the tendency for further and unintended tearing or severing, either during manufacture or during later use of the chain. To lhke the severing easy, the parts to be severed are initially scored. Toprevent further unintended tearing the lines of score are terminated by indentations which break up the normal fibrous structure of the material. The major severing operations are performed, not by one impact, but by a succession of impacts. The distortion of the metal at any one point is reduced to a minimum, and sharp bends, or corners, where tli'e material of the stock is compressed by bending, are provided with creases or indentations which serve to give space for the material compressed, for example along the pintle tongue and at the corners of pintle and hook tongues, where they are bent from' the stock. y

Tlie'successive steps of the operation are as' fellows:

1. The gripping step, the action of the opposed gripping pads, one fixed and one yielding, one on the punch and one on the die. These opposed pads grip the metal stock and prevent its longitudinal movement. Their action is important primaril during the initial feed of the stock through the press, and the chain forming process ma be carried on without them, although un er many conditions they are valuable.

2. The center of the link is next transversely scored as at Z3 to outline the separation between the opposed edges of hook and pintle tongues. shown this score is across the top of the stock, but of course the location of this and ofthe other score and punch marks herein described could be inverted. The opposite side of the ystock is indented as at Z2, Z2, the punch marks indicating the corners of the uture central aperture of the link, and breaking up the regular fibrous structure of the meta-l at those points.

3. As the strip moves forwardly one step, the same area is next operated upon by the opposed scoring knives Z, Z7 which outline, upon the top and bottom of the link, the eparation between hook tongue and the side ZIS. the transverse score Z3, but this is not necessary, since the transverse severing knife Z5 at the same time severs the stock along the score Zsahd bends back the pintle tongue and the end of the hook tongue, the scores Z6, Z7

reachin substantially to the point at which the hoo` tongue is separated from the side bars. The "intle tongue is bent about the bead L?, wiiich makes a transverse crease alonthe inside of the bend, and connects y;

the original separation between iook and pintle tongues. One side of this element further bends the pintle tongue, and bends it about a bead Z, which further enlarges the rrooveror crease Valong the inside of its bend.

he other side further bends the end of the hook tongue continuing its separation from the sidebars, and gives to its end a curve, substantially concentric with the future arc *of the finished hook. Meanwhile the bottom of the stock is punched as at Zw, Z1", the

In the mechanism herein These scores do not extend as far as ;l

punch marks closing the ends of the scores Z6, and serving to prevent the tendency of the link to tear out when the hook tongue is nally bent away from the stock.

5. At the next forward movement of the stock the hook tonvue is operated upon by a punch element which completes its severance from the link side bars and bends it to the position X16 in Figure 2. The previously made indentations Z1", which have broken up the fibrous structure of the corners of the link, prevent weakness and tearing at the base of the hook tongue.

6. At the next forward movement of the stock .the downwardly depending pintle tongue drops over the corners of the die element m20, and prevents longitudinal dis-v tortion of the entire strip to the rear of the point, or shortening of the strip or of the individual links by the impact and distortion action of the forming punches.

Up to this point the sides of the stock have been straight, since there has been no distortion of the side bars. Now, however, the line of separation of the two adjacent links is made along the score Z2() and the link thus separated, is bent to the position shown at the left end of the Figure 2. Meanwhile the hook andV pintle bars are bent vinto the position shown at m5, m7 and the central aperture ofthe link adjacent the pintle bar is slightly widened as at m9.

7. The link is now ready to be severed from the stock and at'its neXt. forward movement it is sheared along the score Z2 and is carried downwardly bythe punch element n2 toward the lower forming die. The hook tongue m1, since it depends farther from the link than the pintle tongue, is the first to Vcontact .the die and is rolled around by the semi-cylindrical die surface ne into the form shown at a7 in Figure 1l. W'hen the link has beenk carried so far down that the pintle tongue also contacts the die, it is bent into finished form. Since it is bent or compressed far more highly than the longer Ahook tongue, the creases or grooves along the inside of the bend of the pintle tongue are extremely important in preventing weakening of the pintle tongue, and the punch marks at the corners are vital in preventing strain upon and distortion of the metal at those points.

The pintle of the precedingly completed link is positioned within the arc of the hook tongue as it is beingcurled into final form, and it therefore curls about the pintle and passes through the central aperture of the preceding link. The pintle endof the link being somewhat widened, as at m9, there is ample room for the hook tongue to pass therethrough. The 'link thus completed is drawn forwardly away from the end of the Stock and at the next movement ofthe stock the succeeding link is fed forward ready for separation and nal formation.

In the form shown in Figure 6 I have illustrated a means for minimizing the effect of the transverse scoring knife in breaking up and weakening the structure of the metal. I provide an opposed scoring knife just sufiicient to break the surface of the lower side of the stock, and I position it between transverse indentations T1 which give space for the metal displaced by the scoring knife L3. Strain upon the metal is so far eliminated as to prevent any appreciable weakening of the fibrous structure of the future link. I also indicate in Figure 6 the creasing element T2 which scores or creases the inside .of the bend of the future pintle tongue, making easier its bending and enabling it to be bent with a substantially reduced strain upon and weakening of the brous structure of the metal. I may dispense with the prick punches, or I may move them a step forward on the die, as shown in Figure 6. c

While I have illustrated an adequate and operative device, and a practical and efiicient process, it will be realized that I do not wish to be limited to the speciiic details and steps shown, or to the specific order of steps'. I wish my description to be taken rather as in abroad sense diagrammatic, and illustrative, since many changes in form and arrangement of steps and the parts used to accomplish the steps may be made without departing from the spirit of my invention.

I claim:

1.*'Ihe process of making chain from a continuous strip of sheet metal stock, which consists in scoring said stock to outline the inner edges of the side bars of the links, severing the metal between said scores and progressively separating a tongue of metal within said scores from the side bars, along the lines of score, by successive impacts upon the tongue, and maintaining the end bars undeform'ed and in the plane of the stock during such impacts until after the separation of the tongue from the side bars is completed.

2. The process of making, from a continuous strip of sheet metal stock, chain comprising links having pintles and hooks struck from the center of the link blank, which consists in first transversely scoring the centralportion of the stock prior to the operation thereon of any forming or severing memllO bers;Y then longitudinally sco-ring the stock to Voutline the inner edges of the side bars and separating the opposed ends of hook and pintle tongue along the transverse score, and rolling them apart in like direction away from the plane of the stock; then separating the hook tongue from the side bars along the line of score; and finally severing the blank from the stock and rolling the hook tongue about the pintle of the neigt preceding link; and maintaining the side and end bars of the link blanks flat and unextended until the separation of the hook and intle forming tongues from the side bars 1s completed.

3. The process of making, from a continuous stri of sheet metal stock, chain comprising lin s having pintles and hooks struck from the lcenter of the link blank, which consists in first transversely scoring the central portion of said stock; then longitudinally scoring the stock to outline the inner edges of the side bars of the links and tearing apart the op osed ends of hook and pintle tongues, an rolling them apart along said transverse score in like direction from. the plane of the stock; then bending the outer end of the hook tongue into substantially arcuate cross section; then downwardly bending the hook tongue and completing its se aration from the side bars; then further ending the hook tongue from the side bars and bending the entire blank downwardl. from the hitherto unbent stock.

4. he process of making, from a continuous stri of sheet metal stock, chain comprising lin s having pintles and hooks struck from the center of the link blank, which consists in longitudinally scoring the stock to outline the inner edges of the side bars, and severing the metal between said longitudinal scores; then indenting said stock ad- 'aent the junction of the side bars and the ook end bar toward which the tongues are to be bent, and separating the hook and pintle tongues from the side bars, by bending them in the direction of the indented side of the stock.

5. The process of making, from a continuons stri of sheet metal stock, chain comprising lin having pintles and hooks struck from the center of the link blank, which consists in indenting the blank adjacent the 'uoton of the side bars and the pintle end ai, longitudinally scoring the stock to outline the inner ed es of the side bars, severing the metal etween said longitudinal scores, indenting the stock adjacent the junction of the side bars and the hook end bar, and separating the hook and pintle tongues from the side bars by bending them in the direction of the indented side of the stock.

6. The process of making, from a continuous strip of sheet metal stock, chain cornliisillg links having pintles and hooks struck from the center of the link blank, which consists in indenting the blank adjacent the inside corners of the junctions of the kside barsY and the end bars, longiudinelly scoring' the stock to outline the inner edges of the side bars, severing the metal between Said longitudinal scores, and separati the hook and pintle tongues from the s' y e bars by bending them in the direction of the indented side of the stock which consists in indenting the stock at the junction of the side bars and the pintle end bar and transversely scoring the central portion of the stock to outline the abutting edges of the hook` and intle forming ton ues; then longitudinal y scoring thc stoc to outline the inner edges of the link side bars; then separating the hook and pintle tongues from each other; then indenting the stock at the junction of the side bars and the hook end bar on the same side Y of the blank as the previous indentation, and bending the hook and pintle tongues in the direction of the indented side of the stock.

8. The process of making, from a continuous strip of sheet metal stock, chain comprising links having hooks and pintles struck from the center of the link blank, which consists in first indenting the blank adjacent the intersection of the side bars and the intle bar, and transversely scoring the blan then longitudinally scoring the stock to define the inner edges of the side bars, and transversely severing the stock between such scores, and creasing and bending the pintle tongue and bending the outerl end of the hook tongue; then further bending the pintle tongue and bending and forming the outer end of the hook tongue to conform substantially to the arc of the latter 'l formed hook, indenting the blank adjacent the intersection of the side bars and the hook end bar, and beginning the separation of the hook tongue from the side link bars along the lines of score; then further creas- 3..

ing the pintle end bar and bending the pintle tongue substantially at right angles to the stock and at the same time shearing the hook tongue from the side bars along the lines of longitudinal score, and bending it at a substantial angle to the stock; then transverselyscoring the stock alon the line of separat1on of the adjacent blan is and at the Vsame time crimping the hook end bar, the

ends of the side bars and the pintle bar, and bending the entire blank to a slight angle in rela tion to the hitherto Hat stock; then shear ing od the blank and bending the pintle toue into final position and rolling the h tongue substantially cylindrically bout dthe pintle of the link previously orme 9. The process of making from a continuous strip Vof sheet metal stock, chain comprisi g links having pintles and hooks lil) from the stock, and opposing said tongue to one of the die elements to prevent longitudinal slipping oi the stock at the moment of impact of opposed punch and die'.

10. rEhe process of making, froma con tinuous strip ot sheet metal stock, chain comprising links having pintles and hooks struck from the center of the link blank,

,which consists in outlining opposed hook and pintle forming tongues, separating them Jfrom each other, and completing their separation from the side bars, unextended, and crimping the hook and pintle end bars out of the plane of the side bars, and bending the link blank at an angle to the stock, in the direction in which the tongues had previously been bent.

11. The process of making, from a continuous strip of sheet metal stock, chain comprising links having pintles and hooks struck from the center ot the link blank, which consists in outlining opposed hook and pintle forming tongues, separating them from each other, and completing their separation from the side bars while maintaining the side' and end bars of the link blanks liat and unextended; bending the hook and pintle end bars out of the plane of the side bars after the separation of said tongues from the side bars, and bending the link blank at an angle to the stock, in the directi .l in which the tongues had previously been bent; and then severing the blank, bending thepintle tongue into iinal shape, and rolling the hook tongue about the pintle oi the previously completed link.

12. The process ot making, from a con-v tinuous strip of sheet metal stock, chain comprising links -iaving lpintles and hooks struck trom the center. of the link blank, which consists in transversely scoring the center ci tne link blank; then'severing the l along such score, bending the pintle tongue, while creasing `the inside of its bend, and bending the end oi the hook tongue; then further bending the pint-le tongue, iurther bending' the end of the hook tongue; and beginning its separation romthe side bars; then further bending the pintle tongue and completing the separation of the hook e from the side bars. Y. The process of making, from a continuous strip ci" sheet metal stock, chain comprising links having pintles and hooks uck from the center of the link blank, wnich consists in indenting the inner corners oit the intersections of the side bars the ci l bars or the blank, severing the hook and pintle tongues from each other and from the e bars, and bending them away irointhe e bars in the direction oi the indented ot the blank, and bending the hook igne about the pintle of the precedingly completed link.

14. rlhe process .of making, from a continuous strip .of sheet metal stock, chain comprising links having .pintles and hooks struck from the center of the link blank, which consists in passing said stock Jforwardlybetween opposed punch and die elements, liiting` said stock from said guide ait-er each forming impact and supporting said stock between and out of contact with said punchY and die elements between the forming impacts at a plurality of points longitudinally opposed along said stock, and feeding said stock forward while so supported.

15. The process of making, from a contin uous strip of sheet metal stock, chain coniprising links having pintles and hooks struck from the center of the link blank, which consists in passing said stock forwardly between opposed punch and die elements, and subjecting each link successively to .their forming action, severing the link from the stock' prior to completing the rolling up oi the hook tongue, carrying said link downwardly below the plane of the die, positioning the chain with the pintle of the link last completed within the periphery of the arc to be described by the hook tongue in course of its formation, carrying said completed link downwardly in unison with the descent of said link, and curling said hook tongue about the rpintle of said link in response to the downward movement of said hook tongue against a forming die.

16. The process of making, from a continuous strip of sheet metal stock, chain comprising links having pintles and hooks struck from the center of the link blank, which consists in transversely scoring the central portion of said stock to outline the separation between the hook and pintle tongues and at the same time transversely scoring the inside oi the bend of the 'future pintle tongue; then longitudinally scoring the stock to outline the inner edges of the side bars, and severing the metal between said longitudinal scores along said trans verse score; then separating the hook tongue from the side bars along the lines oi"A score.

17. The process of making, from a continuous strip of sheet metal stock, chain comprising links having pintles and hooks struck from the center of the link blank, which consists in passing said stock Jforwardly between opposed punch and die elements in a step by step movement, engaging the edges of the stock and liitingsaid stock to a position between and outof contact with said punch and die elements, between the forin-l lill 8 1,7es,ss2

struck from the center of the link blank, which consists in passing said stock forwardly between opposed punch and die elements in a step by step movement, engaging the edges of the stock at a plurality of oints longitudinally spaced there along, an lifting said stock to a position between and out of contact with said punch and die elements, between the forming impacts, feeding said l stock forward one step, between each forming impact, while so supported and holding it against lateral movement and maintaining the edges of the stock substantially unbent and 1n substantially the same plane L., until after the hook and pintle tongues have been completely separated from the side bars of the link.

Signed at Chicago, county of Cook and State of Illinois, this 29th day of April,

RAYMOND W. DULL.

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