US2635738A - Metal drawing apparatus - Google Patents

Description

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Nm QM NON April 21, 1953 w P Avi-:Y ETAL METAL DRAWING APPARATUS Filed April 19, 1949.

April 21, 1953 `w. P. AvEY ET AL METAL DRAWING APPARATUS 5 Sheets-Sheet 2 Filed April 19, 1949 April 21, 1953 Filed April 19, 1949 W. P. AVEY ET AL METAL DRAWING APPARATUS 5 Sheets-Shea?l 3 BY ,17h00/6.4M

April 21, 195.3 w. P. AVEY ET AL 2,635,738

METAL DRAWING APPARATUS April 21, 1953 y w. P.' AVEY ET AL 2,635,738

METAL DRAWING APPARATUS Filed April I19, 1949 5 sheets-sheet 5 ATTORNEY Patented Apr. 21, 1953 METAL DRAWING APPARATUS William P. Avey, New Kensington, Howard H. Herrington, Pittsburgh, Lawrence W. Meyer, Schuylkill Haven, and Joseph E. McLaughlin, Pottsville, Pa., assignors to Aluminum Company of America, Pittsburgh, Pa., a corporation of Pennsylvania Application April 19, 1949, Serial No. 88,392

This invention relates to metal drawing apparatus, particularly to draw benches for drawing elongated blanks such as tubes, rods, bars and the like through a shapingor reducing die.`

An object of the invention is to provide a draw bench capable of drawing successive work pieces through the die in closely spaced succession without intervening operational delay between the draws. f

Another object of the invention is to provide a draw bench with automatic gripping and drawing mechanism incorporating spaced sets of gripping jaws eiTective for drawing successive work pieces without stopping and reversing any of its principal parts, together with yieldable-die mechanism permitting the travelling jaws to close upon the work fully before drawing it.

A nlrther object is to provide in a draw bench a die mounting so arranged that the draw starting shock is absorbed and minimized so as to reduce materially danger of slippage of the gripping jaws from the work or breakage of the work piece and thereby increase the productive eiciency of the draw bench.

A still further object is to provide a draw bench so constructed and arranged that the drawn work pieces will be automatically discharged upon release from the clamping or gripping jaws.

A still further object is to provide a draw bench of generally simplied and improved construction capable or operation at high speeds in which the customary tongs carriage and accessories for operating it are eliminated and effective for sub- 'stantially continuous drawing operations.

A further object is to provide a draw bench of the character referred to incorporating a multiple draw pass arrangement in which the drawing operations at the respective draw passes are eiiect'ed serially in overlapping relation.

The foregoing and other objects and advantages of the invention will become apparent from a consideration of the following detailed description and accompanying drawings in which:

Fig. l and Fig. 2 are plan and side elevational views, respectively, of a single die or draw pass drawing machine embodying features of the invention, intermediate portions of the length of the machine being omitted for compactnessv of illustration;

Fig. 3 is a view on an enlargedscale taken on the line III-III of Fig. 1;

Fig. 4 is a sectional view taken on the line IV-IV of Fig. 3;

Fig. 5 is a cross sectional view taken on the line V-V or Fig., 2, to an enlarged scale;

Spacer 7 claims. (o1. A205-22) Fig. 6 is a vertical longitudinal sectional view on an enlarged scale showing the front or entry end of the machine;

Fig. 7 is a sectional view taken on the line VII-VII of Fig. 6; 4

Fig. 8 is detail plan view of a portion of the draw chain;

Fig. 9 is a diagrammatic layout view illustrating the operative relationship of the draw chain devices;

Fig. 10 is a fragmentary plan view of a modied form of machine illustrating on a reduced scale the die end of a multiple draw pass machine in which the draws are effected serially in overlapping relation at the respective draw passes;

Fig. 1l is a sectional view taken on the line XI-XI of Fig. 10;

Fig. 12 is a cross sectional view taken on line XII-XII of Fig. 11, and

Figs. 13 and 14 are schematic plan and side views respectively of the multiple pass draw chain arrangement illustrating the staggered relationship of the gripping jaws thereof.

Referring to Figs. 1 and 2, the machine comprises, in general, a horizontal frame I0, die mechanism II at the entrance or front end of the machine, drive mechanism I2 at its other end and upper and lower endless draw or ladder chain devices I3 and I4 extending horizontally between said mechanisms and equipped with cooperating sets of gripping jaws at spaced intervals, each set operative to grip the end of a work piece projecting through the die mechanism and draw it through the die.

Essentially, the supporting frame I0 is constructed to aord alinement of the operating parts of the machine and provide rigid longitudinal trackways for the Working runs of the draw chain devices and guideways for the return runs of the chains. In addition, the frame is arranged to provide an unobstructed opening or throat along one side thereof for discharge of the drawn work, as hereinafter described. Any suitable frame construction may be resorted to which serves these ends, a welded construction being illustrated. It comprises upright end stands I5 and I6, each incorporating front and rear, laterally spaced supporting members or channels I'I secured at their lower ends to suitably anchored floor plate I8 and joined at their upper ends by cross piece or I9. Longitudinally, the end stands are spaced apart a distance in excess of the maximum drawn length of work piece. Between them, a plurality of intermediate upright stands 20 are provided, only one of which is shown. These intermediate stands incorporate spaced front and back channels 2l and 22 secured to door plate 23 and further stiifened by upright member 24 secured to back channel 22 and iioor plate 23. The continuity of the front channel 2! is interrupted at a point slightly below the draw pass line through the machine so as to form a gap 25 (Fig. 5) to accommodate discharge of drawn work pieces, as hereinafter described. As shown in Fig. 5, the upper and lower portions of front channel 2i are connected to back channel 22 by web plates 25, the upper portion of member 2I, consequently, being supported cantilever' fashion from the back channel.

Extending horizontally and secured to the supporting stands I5, I6 and 20 are vertically spaced sets of track forming members comprising upper angles 21, intermediate, vertically disposed channel members 28 and lower rail members 2S. Below rails 29 is a stiffening and supporting channel 39 having vertical bars 3f to which the rails 29 are secured for additional support. Similarly, vertical bars 32 tie the rails 21 and the channels 28 together for mutual support. The bars 3i and 32 also are vertically spaced from each other, as shown in Figs. 2 and 5, to provide a gap for passage of drawn work pieces therebetween.

The rails 21 and 29 and the channels 28 are provided in pairs directly opposite each other as shown more clearly in Fig. 5, and provide laterally spaced, longitudinally continuous trackways for accommodation of the ladder chain devices I3 and I4 hereinafter to be described. The channel members 28 are so located with respect to the draw pass line that their upper and lower flanges e3 are equi-distant above and below the pass line. Secured to the inner face of the web of each track channel 28 is a continuous inner track member 34 in the form of a channel having flanges 35 parallel to and spaced from the flanges 33. The opposed faces of these flanges 33 and S are machined smooth and cooperate to form trackways for the opposed working or operating runs of the upper and lower ladder chain devices I3 and Id whereby these runs are rigidly maintained in predetermined spaced apart relation relative to the pass line and in parallelism therewith.

Each of the ladderV chain devices I3 and I4 referred to comprises a pair of laterally spaced roller and link chains 3B and 31 and each chain is joined to the other by cross members or bars preferably in the form of through pins 3S spaced say 3 links apart in the direction of the length of the chains. The links of the chain intermediate these cross connecting members are joined in usual fashion by short pins 39 (Fig. 8). At the front end of the machine, the chains 36 and 31 pass around spaced apart, verticalk sprockets dil, the sprockets and their spacer sleeve 4I being mounted on a cross shaft 42 journalled in bearing blocks 43 supported on the upper side of forward extensions 44 of the track channels 28. The actual trackways formed by channels 28 and 3d terminate on a line with a vertical plane through the axis of shaft 42, a portion of flanges 33 being cut away for sprocket clearance (Figs. 6 and '1), which results in the rollers of the side chains 36--31 as they leave the sprockets directly engaging in the respective upper confining trackways. Above and to the rear of sprockets 40 are vertical sprockets 45 carried on a cross shaft 46 that is journalled in bearing blocks 41 supported on brackets 48 secured t0 and. @Xlindng fOr- CII fus

4 wardly from the upright members I1. The sprockets i5 receive the chains from the upper return rails 21 from which sprockets the chains pass around the sprockets 40 and enter the trackways adjacent the pass line. Similarly, the lower ladder chain I4 passes around sprockets 4S and 5 supported and arranged in identical fashion to` sprockets di! and 45 and in line below them, so that the chain I4 travels from the return guide rails 25 upwardly around sprockets 5I) and 49 and enters the lower coniining lgrackways.

At the drive end of the machine, the respective chains I3 and I4 pass from the connning trackways onto oppositely inclined guide rails 5I and 52 and around upper and lower vertical drive sprockets 53 and 54 to the upper and lower return rails 21 and 253, respectively. In lieu of the rails 5I and 52, idler rollers or sprocket wheels may be used, as desirecLat the points of divergence of the chains from the trackways to the respective sprockets 53 and 54. The divergent paths thus provided for the chains IS-I at the end of their parallel working runs and ahead of the driving sprockets cause grip jaws carried by the chains to automatically release their grip upon a drawn work piece and permit its gravity discharge without interference with the necessary driving mechanism. A target plate 55 centrally located in the divergent throat between the chains stops travel of the work piece after being released by the jaws.

Drive sprockets 53, spaced by sleeve 5S, are keyed or splined on cross shaft 51 that is supported in bearings 58 secured to each of the uprights I1 (Fig. 4). A spur gea-r 59 is nxed on one end of shaft 51 and it is in mesh with pinion E@ fast on shaft 6I supported by spaced bearings 62 carried by supporting webs 53 on the uprights I1. Pinion IBB is in mesh with a duplicate pinion 54 fast on one end of cross shaft 65 that is supported in bearings 56 also secured to the webs t3. A driven spur gear 61 is fast on the other end of shaft 65 and meshes with a drive pinion t8 keyed to drive shaft ed. Sprockets 5s, likewise spaced apart by a suitable spacer 1t, are keyed on sleeve shaft 1I that is journalled in bearings 'I2 secured to each of the uprights I1. A spur gear 'I3 of the same size as gear 59 is keyed on shaft 1I and meshes with the pinion 54. Drive shaft 5S is rotatably supported in the sleeve shaft 1I and further supported in bearing block 13a that is mounted upon a bracket 14 carried by one of vthe uprights I1. Shaft 69 isV adapted to be driven by means of a multi-V-belt pulley 15 fast thereon and driven from a motor 16 through motor pulley 'I1 and V-belts 18, the motor being mounted on base 19 suitably adjustably carried on supporting frame 80. Other suitable driving means may be employed as desired, it merely being necessary to impart synchronous driving movement to the chains I3 and I4 to cause the operating runs thereof to travel in unison in the same direction; that is, away from the die mechanism as indicated bythe arrow in Fig. 6.

Reference has heretofore been made to cooperating sets of gripping jaws carried by the ladder Lchains I3 and I 4. l'wo sets of such jaws are preferred, spaced from each other longitudinally one-half the total length of the chains whereby when one set ,is brought into gripping relation with a Work piece and is pulling it through the die mechanism the other set will be removed therefrom and be returning to starting or work-gripping position. Thereby, successive work pieces may be drawn Ain closely Y spaced succession with elimination of operational delays incident to returning gripping jaws to the die mechanism which conventional carriage mounted jaws entail.

Each set of jaws, as best seen in Figs. 6 and 7, comprises two jaws 82; one mounted in the recessed outer face of holder block 83 carried by chain I3 and the other mounted in identical holder` block 84 carried by the chain I4, whereby travel of the chains brings the jaws into opposed relationship to grip the pointed end 85 of a blank or work piece projecting through the die between the outer or opposed toothed faces of the jaws. Each holder is transversely bored adjacent to its front and rear ends on centers corresponding to the pitch length of the chains 36 and 31 through which bores supporting pins 86 corresponding to the cross pins 38 extend, each holder being disposed between the side chains. The jaws 82 are aixed to their holders in each case by means of a single screw or bolt 81, the side walls of the recesses in which the jaws are fitted serving to keep them oriented in the holders. To take up wear and accommodate the jaws to various point diameters washer shims 88 are insertable between the bottom of the jaws and their holders, the washers being slotted so' that they may be slid past the attaching screws 81 when they are loosened.

The front bore through each holder is elongated (see Fig. 6) in a direction normal to the travel of the holder and a spring clip 89 carried by the holder and engaging the inner side of the front supporting pin 85 normally urges the forward end of the holder inwardly, or towards its carrier chain, but provides and permits limited outward movement thereof, the holder pivoting about the rear supporting pin 86. In other words, the jaw when idle is normally held in such an inclined or angular position relative to the chains that its leading end projects outward less distance than its trailing end and consequently as the jaws travel around the entry sprockets 40 and 49 into gripping position they engage the point 85 at a ilatter. angle than otherwise would be the case `and thus reduce the danger of gouging and breaking the point 85. In addition, the jaws by reason of the limited pivotal movement of their holders on the rear pins 86 automatically tighten their grip upon the work as the pull increases and thus 7 accommodate eiectively for variations in point sizes, thereby assuring positive gripping and pulling of the work through the die despite such variations as are usually encountered.

The die mechanism comprises a die 90 that is provided with a desired drawing aperture therethrough and is mounted in an open top holder y9| so that the die can easily be removed and replaced, as desired. The die holder 9| is secured to one end of a hollow piston rod 92 through which the pointed end of a work piece is inserted rand passed through the die aperture into position for gripping between the jaws 82, as shown in Fig. 6. rlhe tube point is guided into the die by an interiorly tapered guide insert 92a, positioned in the bore of the piston rod in front of the die. The piston rod 92 carries a piston 93 working in a cylinder 94 that is secured to the face of a supporting block 95 opposite from the die holder 9|, block 95 suitably beingsecured I to the forward extremities of extensions 44. A cylinder cap 91 closes the outer end of cylinder 94 and the piston rod is extended therethrough and slidably supported thereby.Y OnV the die side of the block 95. the piston rod is slidably supported in a bushing 98 carried by a retainer plate 99 which retains a packing gland |00 in position to prevent loss of air pressure from the cylinder, the piston 93 being provided with sealing cup |0| or other suitable sealing means to prevent loss of pressure past it. A guide rod |02 attached to the die holder 9| and slidably extending through block 95 maintains the holder 9| and die 90 against rotation, but permits longitudinal movement thereof. Y

Air under pressure is continuously supplied to cylinder 94 at its die facing end through a duct |03 in block 95 with which duct air pipe |04 is connected. The pipe |04 is supplied preferably through a pressure regulator (not shown) from any suitable source of supply. The piston 93 is normallymaintained at the far end of cylinder 94, the left hand end as Viewed in Fig. 6, by the air under pressure in the cylinder. Since the travelling grips or jaws 82 are moving continuously, when they close upon a point to start a drawing operation, the die holder and contained die move along with the work piece against the yielding resistance aiorded by the air pressure in the cylinder in front of piston 93 until they reach drawing position with the piston solidly engaging against the face of block 95, as shown in broken lines in Fig. 6. This limited movement of the die from its normal retracted position to its solid drawing position materially reduces the shock incident to the start of the actual drawing operation and at the same time it is of such extent that it allows the jaws to close into full length engagement with the point without danger of slippage concurrently with the die reaching solid drawing position. During the shock absorbing movement of the piston, the air trapped in front of the piston is further compressed; and by initial adjustment of the air supply pressure, the desired degree of shock absorption and smoothness of operation to suit the operating conditions may be had. It is contemplated that a compression spring arrangement may be used to afford the shock absorbing die motion in lieu of the air pressure arrangement described.

The operation of the machine thus far d-escribed in the drawing of successive blanks or work pieces will be apparent from the foregoing description. In brief summation, with the die in its initial retracted position, as shown in full lines in Fig. 6, a pointed end of a work piece is inserted by the operator through hollow piston rod 92, guide 92a and through the die aperture into position to be gripped. One set of jaws converge upon the point from opposite sides and progressively move into gripping relation therewith during which action yielding movement of the die towards its drawing position (shown in broken lines in Fig. 6) occurs to lessen the shock incident to starting the draw. By the time the die reaches drawing position, the rollers on the cross pins 85 on which the jaw holders are vmounted will have entered the parallel trackwaysand the jaws will have come into full length gripping engagement with the point 85. The jaw holders will pivot about their rearmost supporting pins and thus automatically tighten the grip .of the jaws upon the point as drawing tension increases. The work pieceis now drawn through the die, the succeeding set of jaws returning idly on the outer return rails towards the die. When .the end of the piece leaves the die the draw is completed, but the jaws donot open or release the drawn piece until the throat of the active chainy pass is reached at which point the jaws angle away from each .ether and release the work piece, the end of the work piece butting against the target plate .55. Spring clips secured to the trailing ends of .the jaws or the holders, as desired, and in pressing contact with the work piece during the draw serve to strip the point from either' of the Vangularly moving jaws in case the point should tend to stick to the jaw, thereby assuring proper release of the work piece from the jaws. This feature is found to be quite desirable in drawing of work of small cross section and thin wall in the ,case of tubing, such as T3@ inch tubing for example. It eliminates the danger of such light tubing from sticking to a jaw and becoming jammed against the adjacent edge of the target plate 55.

It is easy to pull long lengths of drawn work pieces specially those referred to of small cross section, but it is quite difficult if not impossible to push such exible lengths in a straight line so as to effect endwise discharge thereof from the draw bench. According to the invention, automatic lateral discharge of the drawn work pieces from the draw bench is effected in order to avoid increasing the overall length of the machine. To this end, the lateral gaps in the frame work above described have been provided. Disposed transversely of the machine and sloping downwardly through these gaps are receiving and discharging members in the form of tables or plates |06 that are hingedly secured at their back edges on a pintle pin |81 secured at their ends to the back members of the stands I5, I6 and 2D. Vertical clips |68 secured to the front members of such stands support the plates |06 from underneath, attaching screws |89 extending through elongated slots permitting vertical adjustment of the clips whereby the angle of slope of the plates it vmay be adjusted. With reference to Figs. 2, 8 and 9, each of the cross pins 38 of the upper chain I3 has journalled thereon a peripherally grooved roller I0 and the lower chain I4 is provided with similar rollers As indicated in Fig. 9 such pins 3'8 and rollers III on the lower chain I4 are provided for only about one-half of the distance from one jaw holder 84 to the next jaw. Moreover these cross pins and rollers on the lower chain are provided in trailing relation to the respective jaw holdersthat is, behind the holders in the direction of movement thereof away from the die. Thereby, vertical gaps through the lower chain are provided, each of which extends from the last trailing roller indicated at I la to the front of the succeeding jaw holder Bti.

During the draw the work piece is, of course, under draw tension and quite straight. When it leaves the die, it bends or sags down from its gripped end into restrained engagement with the rollers on the lower chain I4, while its free end portion beyond end roller l la sags down still further through the gap in the chain Il! to a position below the plane of the operating run of this chain, as indicated in Fig. 9. In this position, the piece is pulled along behind the working jaws until the jaws enter the divergent throat and open up and release the piece, as heretofore described; the end of the piece striking the target plate 55 and hence remaining stationary while the chains move onward relatively thereto. Tilting of the released work piece is limited by the rollers I I0 onlthe upper chain I3 with which the piece is adapted to engage, the grooved peripheries of the rollers preventing lateral displacement of .therwork piece. By reason of the provision of the rollers ||0 and I I i on both chains, relative movement between the chains and the work piece can occur without in any way damaging or scratching the surface of the stationary work piece. As the chains move longitudinally of the released work piece, the trailing rollers I I I move lengthwise of the piece and allow it progressively to move down onto the receiving members IBB until the rollers III and |I0 no longer restrain the work piece and it gravitates full length onto the receiving plates and discharges therefrom into a suitable receiver or rack I|4 disposed along the free edge thereof (Fig. 5). In this manner, the work piece is automatically discharged without any attention from the operator. The operator will, of course, insert a succeeding blank into the machine when the preceding piece emerges from the die which -blank the jaws approaching the die will close upon, draw through the die and discharge in the same manner as heretofore described.

In the embodiment of the invention illustrated in Figs. 10, l1 and l2, the supporting framework is widened suiiiciently to accommodate four lines of chain runs disposed in side-by-side relation and four shock absorbing die assemblies, each of the same construction as above described, to provide a multiple draw pass machine. Due to the elimination or travelling draw carriages, the width of the machine is less than the arms reach or" the operator thus enabling him to conveniently-feed successive work pieces into the the respective die assemblies. The drive end (not shown) incorporates the same divergent track, target plate and drive arrangement as previously described. The draw passes are identiied as No. I, No. 2, No. 3 and No. Il, respectively, and each consists of a die assembly and an opposed pair of draw chains provided preferably with two cooperating sets of gripping jaws spaced 180o apart, the respective sets of jaws being identied as Ia-Ib, Ecl-2b, etc., in Figs. 13 and 14.

The die assemblies may have a common elongated supporting block a secured to or integral with a horizontal plate I2t carried by brackets 12| that are suitably attached to the front and rear channels I la. of the end stand I5a. The sprockets 4ta-@5a and 45e- 5ta for the opposed pair of draw chains of one draw pass are vertically alined as shown in Fig. ll and their supporting shafts are journalled in bearings |22 secured to the outer faces of the webs of the channels ila, the corresponding sprockets of the adjacent chain runs or draw passes being mounted on these common shafts, together with such spacers between the sprockets as may be necessary to prevent their shifting axially.

The active runs of the respective chains are Vreceived in longitudinally continuous trackways formed by facing pairs of channels E23 and |24 disposed above and below the pass line, and the return runs of the chains are supported on return track angles 25a and 29a, these track channels and angles being duplicated for each of the draw passes. TheV intermediate track channels |23 ,and |255 are supported on I-beam sections |25 suitably laterally spaced apart and secured to the underside of a cross beam |26 of each of the intermediate frame stands 28a, while the outer track channels are supported on channel sections |21. If desired, the previously described inner and outer channel arrangement of channels 34 and 28 may be used to providethe chain supporting trackways, in which case the sheaves with respect to those" of the adjacent draw passes.

To facilitate lateral discharge of the drawn work pieces through the discharge gap 25a of the supporting framework, transverse or cross belts I3!) are provided at longitudinally spaced intervals between the intermediate stands 20a in position to receive each work piece as it drops down through the lower draw chain, as heretofore described. These belts are supported on pulleys |3| and |32 mounted on longitudinal shafts |33 and |315 journalled in suitable bearings at the front and back side of the framework, the bearings for the rear shaft 33 being adjustably mounted so that the belts may be kept tight on the pulleys. A supporting plate |35 may be disposed beneath the upper run of the belts to support them against sagging. Pref-- erably, one of the shafts is continuously driven by a suitable drive motor (not shown) at a slow rate to cause belt travel in the direction of the arrow in Fig. l2. The work pieces, after dropping down onto the top runs of the belts, are carried thereby outwardly through the gap 25a of the framework and discharged from the belts into receiver Illa.

Referring to Figs. 13 and 14, the gripping jaws y of the respective draw lines are disposed in staggered relation relatively to each other so that the drawing operations are carried out serially in overlapping relation. This allows a single operator to feed successive work pieces into dies l, 2, 3, 4 in repetitive order, for maximum production and practically no idle machine time. By uniformly staggering the sets of jaws of the respective draw passes, the power demand of the machine is rendered substantially uniform instead of being alternately maximum and minimum, as would be the case with a non-staggered relation of the jaws, and less destructive forces are thus imposed on the machine. Thus, assuming jaws la to be moving through draw starting position, jaws 2a and 3a. will be drawing their respective work pieces through dies 2 and 3, while jaws 4a will have completed their draw. Consequently, the power load on the machine will be that required to draw three tubes continuously. Jaws 4b, 3b, 2b and ib will be returning to draw starting position, the operator inserting a work piece into die No. 4 for gripping by jaws 6b when they reach starting position, by which time jaws 3a will have completed their draw. Thus, it will be clear that the jaws by reason of the uniformly staggered relationship will arrive at draw starting position at regularly spaced intervals. By adjusting the driving motors speed, the periods of arrival of the respective sets of jaws at their starting position may be varied, as needed.

It will be apparent from the foregoing that a drawing machine which accomplishes the objects initially set out is explicitly described to explain the principles and construction of various features of the invention as incorporated in particular embodiments thereof. However, it is to be understood that, within the scope of the appended claims, various features of the invention taken singly or in combination may be practiced otherwise than as herein specifically illustrated and described.

What is claimed is:

1. In a draw bench for tubes, bars and like work blanks, pointed at one end for insertion through the aperture of a draw die preliminary to being drawn therethrough, pulling and discharge mechanism fory such work blanks compris-' Aing an upper and a lower pair of laterally spaced endless chains having adjacent active runs extending along the draw line for said blanks in spaced parallel relation thereto, elongated side members contiguous to the outer sides of said active runs and having an inwardly facing guide channel way for each of said active runs, rigidly holding them in parallelism, longitudinally spaced pairsl of vertically aligned idle and drive sprockets for said chains, means for driving said drive sprockets, gripping jaws carried on corresponding points on both pairs of chains, two jaws only on each pair of chains, disposed between them and spaced apart, thereby constituting two spaced sets of jaws operable at said idle sprockets to grip the pointed ends of successive blanks and pull them through and beyond the die to a jaw opening position adjacent to said drive sprockets, said guide channel Ways terminating in divergent guide surfaces at said jaw opening position for release of the jaws from a drawn blank, the longitudinal space between the jaws of the lower pair of chains providing a discharge gap ahead of each jaw through which the trailing end portion of the drawn blank after leaving the die is adapted to sag to a` point below the plane of said active runs of said lower pair of chains, cross members carried at spaced intervals along the chains of said lower pair in trailing relation to each jaw thereon for a portion only of said longitudinal space between the jaws, to limit the extent of sagging of the drawn blank, a stop at said jaw opening position for arresting travelling movement of the drawn blank for progressive sagging discharge as said cross members thereunder move lengthwise relatively thereto, and receiving means below said active runs of said lower pair of chains and arranged transversely thereof for receiving the discharging blank and moving the same to one side of the draw bench.

2. The construction deiined in claim 1 further characterized by the provision of rollers journalled on said cross members, said rollers being peripherally grooved for restrainingly supporting the drawn blank prior to its release by said jaws and affording rolling contact with said drawn blank during said relative lengthwise movement.

3. The construction defined in claim 1 wherein said receiving means comprises inclined members sloping downwardly and outwardly to one side of the draw bench for gravitational discharge of the drawn blanks therefrom.

4. The construction defined in claim 1 in which each of said cross members are co-aXial with the pivotal axes of adjoining links of the said chains and serve as connecting pins therefor, and rollers between said links and journalled on said pins.

5. In a draw bench, a travelling draw chain comprising links, pivot pins including a pair of adjacent elongated pins joining said links, a jaw holder having front and rear transverse bores therethrough receiving said elongated pins therein, a blank gripping jaw detachably secured to the outer face of said holder, said front bore being elongated in a direction normal to the line of travel of said holder to provide limited pivotal movement of the holder on the pin in the said rear bore thereof, whereby the jaw automatically tightens its grip upon a blank with which it is adapted to engage, and spring means normally yieldingly holding said holder in an inclined idle l1- 'position with. the. euterend of ite elongated Yfront here hearing againet the pin tl-iereinv 6, a draw bench, a travelling draw chain eeneieting of laterally epaeed Side Chaine, eaoh comprising links and connecting pins therefor, an adjacent pail` of said pins being elongated and egtending from one side Ychain tothe other and uniting them, Similar elongated pins cross-een.- neeting Said Side ehainel at other predetermined intervals, a Jaw holder diepoaed betweensaid Side ehaina and having iront and rear transverse hores therethrough through each of Which one 'et the pins of eaid pair of elongated pins extends vvhereby to Support Said holder, a blank gripping iavv detaehably secured to the outer face. of said holder, said. front bore being elongated a diret,u tien norinal to the line of travel of the holder to provide limited pivotal movement of the. holder on its rear Supporting pin whereby the jaw antolnatieally tightens, its grip upon a. blank. with Whieh it is adapted to engage.` and Spring means normally yieldingly holding said holdler in.. an inelined idle position. with the outer end of. its elongated front here hearing against yite front supporting pin- 7- In` draw bench for drawing tubes, bare and lilie Worn pieces, pointed at one end for threadinev through, the aperture of a draw die preliminary to being drawn therethrough,Y mechanism for pulling such work pieces through the die and antornatioally dseharging them. laterally from the draw bench comprising a pair of horizontally extending endleee. Chain devioeS mounted in vertieally Oppeeed relatien and having adjacent, parallel operating runs egually spaced above and below the draw line for said work pieces, mounting sproclrets for said chain devices,k adjacent to and remote from said die, respectively, means for driving Said remote Sprockets, laterally spaced parallel track members cooperating with said operating runs to hold them rigidly in parallelism, outwardly facing gripping jaws carried by said chain devices, two only on each spaced 180 apart, and located at corresponding positions lengthwise on the respective chainV devices, whereby to grip successive work pieces and pull them through and beyond the die to a jaw opening position adjacent to said remote sprockets, said chain device below said draw line comprising a pair of laterally spaced chains forming an elongated work discharge gap therebetween in front of each of the jaws thereof, for downward discharge movement of the drawn work pieces when released from the jaws at said jaw opening position, and means disposed beneath the operating runs of said laterally spaced chains ,and arranged transversely thereof for receiving the work pieces discharging through said gaps and discharging them laterally from one side of the draw bench.

1VV'ILLIAIVI P. AVEY. HOWARD H. HERRINGTON. LAWRENCE W. MEYER. JOSEPH E. MCLAUGHLIN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 518,403 Haas Apr. 17, 1894 1,124,761 Lloyd Jan. 12, 1915 1,139,884 Millen May 18, 1915 1,321,463 Lloyd Nov. 11, 1919 1,321,729 Frel Nov. 11, 1919 1,360,275 Donnelly Nov. 30, 1920 1,759,105 Evans May 20, 1930 1,779,479 Leech Oct. 28, 1930 2,294,138 Strock Aug. 25, 1942 2,488,579 Bunch Nov. 22, 1949

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