US998969A - Toggle drawing-press. - Google Patents

Description

W. KLOCKE 6L F. ORTON.

. TOGGLE DRAWING PRESS.

APPLICATION FILED FEB.17, 19114 998,969, Patented July 25,1911.

ll SHEETS-SHEET l.

. Y A JQ; l, WITNESSES: um 074D,

W. KLOCKE & P. ORTON.

TOGGLB DRAWING PRESS.

APPLICATION FILED H1117. 1911.

998,969. I y Patented July 25,1911.

11 SHEETS-SHEET 2.

' INVENTORS i 74M M WITNESSES: W ffeamlc /arv,

: 94M A 1' [Hur/nys,

W. KLOGKE L F. ORTON.

TOGGLE DRAWING PRESS.

APPLICATION FILED PERA?, 1911. 998,969l Patented July 25, 1911.

11 SHEETS-SHEET 3.

WITNESSES: 9 .M01/M .Q4/M

W. KLOCKE & F. ORTON.

TOGGLB DRAWING PRESS.'-

APPLICATION FILED PBEM, 1911.

11 SHEETS-SHEET 4.

w `c FE M A WITNESSESI W. KLOCKE & F. ORTVON.

TOGGLE DRAWING PRESS.

APPLICATION FILED IMJ?, 1911.

E F t WIINESSES:` QM MJJ/ am C OMM wm 5 e ma m W. KLOCKE & F. ORTON. TOGGL DRAWING PRESS.

APPLICATION FILED Hum?. 1911.

998,969, Patented July 25, 1911.

11 SHEETS-SHEET 6V.

WITNESSES: l 'w 3fm By Attorneys,

W. KLOGKE & F. ORTON.

TOGGLE DRAWING PRESS.

' APPLICATION FILED P13317, 1911.

1 wm m E ,H O 5S T. IMM 2L N H1.. d, .NUM W man 1mm N 1|. I.. t HW w Im ,/z@ P W27 m w m Y n WITNESSES:

W. KLOGKB 9F. oToN.

TOGGLB DRAWING PRESS.

APPLICATION FILED FEBJ?, 1911.

Patented July 25, 1911.

11 SHEETS-SHEET 8.

, 1 INVENTQRS;

WITNESSES: w Me W. KLOCKE & F. ORTON.

TOGGLE DRAWING PRESS.

APPLICATION FILED IBB.17, 1911.

Patented July 25,1911.

11 SHEETS-SHEET 9.

l INVENTDRS "M7- By zomeys, @mar-wn. @IWW WITNESSE:

W. KLOCKE L F. ORTON.

TOGGL-E DRAWING PRESS.

APPLICATION FILED 11:13.17, 1911.

` 998,969. Patented July 25,1911.

11 SHEETS-SHEET 10. I',

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Il TABL Il l l,

INVENTORS;

WITNESSES: 1 wm, n ZM 2. 4 By zfowzeys,

ra/104k 1 Y 5W` w wq W. KLOOKE & P. ORTON.

TOGGLE DRAWING PRESS.

APPLICATION FILED Imm?. 1911.

998,969. Patented July 25, 1911.

11 SHEETS-SHEET 11.

Fig. 18

-- INVENTORSK: @u 46M@ WITNESSES: W @'r/aw, M 99M 1' /far/lfg's,

holding table sufficient for the maximum.

' STATES PATEN onirica WILLIAM KLOCKE AND FREDERICK ORTON, 0F NEW YORK, N.. Y., ASSIGNORS T0 E. W.

BLISS COMPANY, 0F BROOKLYN, NEW YORK, A CORPORATION 0F WEST VIRGINIA. f

TOGGLE DRAWING-PRESS.

To all whomt may concern:

` Beit known that we, WILLIAM KLOCKE, residing in the borough of Brooklyn, county of Kings, city and'State of New York, and

FREDERICK ORTON, residing at Glendale, In the borough and county of Queens, city and State of New York, both citizens of the 'United States, have jointly invented certain new and useful Improvements in Toggle DrawingPresses, of which the following is a speciiication.

This invention is directed to the production of a drawingl press having a toggleoperated table, wherein the table and punch shall have each a variable stroke, and the punch a quick-return stroke. Y

The invention also provides certain other or secondary advantages as will be described.

Although otherwise useful, the invention is chiefly designed for large and heavy presses such as are used fordrawing steel cups or shells of large size, say for example of a length approximating three feet and a diameter approximating two feet. For drawing such shells from a flat plate it is necessary to resort to several Asuccessive drawing operations. Of these the first is of large'diameter and short stroke, the following operations being successively'of smaller diameter and longer stroke, until the nal operation of maximum stroke and minimum diameter produces the finished cup or shell. As the expense of such heavy presses is Aconsiderable, it is desirable to be able to utilize one machine foreach of the successive drawing-operations required to produce such .a shell, vas well as, for other or analogous operations, These varied uses necessitate a.

press having a stroke of punch and of blank length of shell `to be drawn. They' also necessitate that the machine shall have sufficient strength and power to draw shellsof the maximum diameter to be produced. AS the punch pressures required are roughly in proportion to the diameters of the shells being drawn, and as for'ny given shell the- A relative diameters of the shells produced at f lows that the punch pressure for the firs drawing is about double` that required for the iirst and final drawing operations are approximately as 2 to 1 respectively, it folthe final drawing. The power required to drlve the press at any ,instant-while drawing Specification of Letters Patent.

Application 1ed.February 17, 1911;

Patented July 25, 191i. seria; No. 609,192. l

is proportional to the punch velocity.mu1

tiplied by the punch pressure This power 1s very considerable in largework, and affects the dimensions of thetrain ofgears, with their shaftsI and bearings, leading back from the crank shaft of the lpress to and including the motive power apparatus, which vis commonly an electric motor. -It is some-` times desirable that the power required to drive thek lpress be maintained as nearly constant asv possible, whatever may be the work which the press is called upon to perform, in order to avoidproviding greater motive power and greater strength of the power-transmitting parts of the press' than is suiicient for average requirements. The occurrence of the maximum work is so 'infrequent that it is undesirable to' build presses of this very costly type strong enough to do the heaviest work at the highest speed; hence an important economy` is effected by the ability to speed down the press for work exceeding the averagepower requirements. I If a press having Van invariable'length of stroke were run at a"v uniform speed forV ydrawing. both long and short shells, the v greatest (at.

largest 'diameter and requires the greatest punch pressure. The length ofthe strokel of such a press would be determined by the longest shell to be drawn, which vwould be in excess of the requirements for drawinga short shell. In a variable stroke press, how- `ever, such as our invention provides, the

stroke may be reducedY for drawing' the short shell with corresponding reduction in punch velocity, and Increased distances-of crank and gear rotationduring the. drawing period 1 of the punch, .resulting in lower stresses and lesser power demand atany instant ,and permitting of lesser dimensions of gearing, shafts, bearings, etc., and offa lower motivel power, and a reduction'of space occupied by those Aportions of the machine' and by the motor yused to drive the machine, all without reduction ofthe number of strokes per minute performed. Thus -the Vvariable between :the crank shaft and the'4v punch sov los' l stroke is a menS .0f .Changinghe 'leverage greater Apressure through ia shorter distance without increasing stresses in driving gearing, and without demanding increased moh "f son for shortening the table stroke 1s that tive power.

The speed of drawing presses, or number of strokes per minute, is `limited by the highest punch velocity that can be used without causing the sheet metal to tear in drawing. In those cases where there is ample drawing power, and when it is desirable tofbuild the power-transmitting parts of the lpress of sufficient strength, the

, press may be adaptable for a variety of operations requiring a considerable div/ersity ofvpower.A If a press is to be used for such variety or operations, some requiring less punch stroke than others, it isevident that by shortening the stroke for some of the operations, the rotative speed, or the number of strokes per minute, can be Vincreased in inverse ratio to the reduction of stroke without increaseAof punch velocity; resulting in a greater average production of shells in a given time than would be possible with a press having an invariable length of stroke. Thus the variable stroke is a means permitting of an increased number of strokes in a given time for operations requiring less than the maximum length of stroke of the press, greatly increasing the productive eiiciency of a press that is driven by a variable speed electric motor, or a press receiving power vfrom anyltransmitting agency that has the function of altering the speed of the driving belt of the press. Furthermore the variable stroke has an addedA advantage in combination with speedv change gearing in the driving -gear of the press itself, obviating the necessity of employing either a variable speed motor or any `extraneous speed changing devices. The imparting of'a variable strokev to the blank holding bed or table also has important advantages.- The table stroke when drawing long shells that are to be removed from the press from over the'die is necessarily longto create space for the removal ofthe shell from over the die, and between the die and the bottom of the punch, or the bottom of the stationary blank holder, when the die has descended I and thepunch ascended to their stopping positions.

If however a long shell be pushed through the die to b removed from the press from underneath the table, then the table stroke need only be as 'long asnece'ssary to create space for the introduction of the succeeding shell that is to be placed on the die for redrawing, and the length ofwhich 'will be considerably less' than the redrawn shells that are pushed through the die and removed from under# neath. The lesser stroke of the table necessary under these conditions is desirable in that it leaves a greater space beneaththe bottom of the table when the table is' down,

which greater space facilitates the removal of the push-throughl shells. Another reatable counterweight, which by the increasedv inertia and momentum at the maximum number of strokes would result 1n unnecessary stress in moving parts and wear of joints.

The feature of imparting lto the punch a quick return movement is important in.

that by reducing the time ofthe idle or upstroke of the punch, it so extends the relative time of the drawing stroke that the press can be speeded up to a considerably higher number of strokes per minute than a press of the same dimensions devoid of this feature, without causing the maximum drawing velocity of the punch to exceed that of such other press. alone the productive capacity of the press is increased by from 20 to 25 per cent.

. Having thus indicated the leading features of our invention and the advantages thereof, we will proceed lto describe a drawing press constituting an embodiment of our invention in its preferred form. Such press is shown in the accompanying draw'- ings, wherein,-

Figure 1- is a front elevation ofthe press; Fig. 2 is a plan thereof; Fig. 3 is a side elevation viewed from the left; Fig. 4 vis a vertical mid-section also viewedv from the left; Fig. 5 is a vertical section on a larger scale than Fig.- 4 showing the punch, blankholder, and their operating parts in the act of drawing a shell; Figs. 6, 7 and 8 show one of the rocking levers through which power is transmitted to the punch slide, being respectively a side elevationI partly broken away, a. plan, and a front view in vertical section. Figs. 6 and 8 show also the lower end of the rod S. i Fig. 9 is a horizontal section in the plane of the line 9-9 in Fig. 3, certain parts being'omitted; Figs'. 10 and 10 are plans of two of the shafts in Fig. 9; Fig. 11 isa skeleton view 'corresponding to Figs. -3 and 4, except that the parts are shown in a different position,v the center lines and ppi-vf A otal connections of the press being indicated By this means or starting position of -the machine; Figs.

12, 13 and 14 are'diagra'ms showing successive positions of the table operating mechanism; Fig. 15 'is a. diagram or time chart showing the .relative movements of. the

the drawings, the fixed framework of the machine Acomprises a massive base or bed A, parallel upright side frame B B, with a cross frame C uniting them above, their eX- tensions B B above the cross frame being tied together at top by tie rods b o. The

base A has a rearward extension A forming a frame for the speed changing gearing. The 4blank holder D (Fig. 5) is mounted against the usual equalizing ringE carried at the lower end of a blank holder frame F, which is fixedly, and adjustably mounted in the cross frame C. 'For transmitting the tensile or blank-holding stress between this .cross frame C and the base A, the two are connected by pairs of upright rods C fitted with heads or nuts.

Ihe punch G (Fig. 5 or 16) is carried upon the punch plunger H, which is v'ertically adjustable in the lower memberl of a sliding cross head J, which' is vertically movable in guideways j j formed in the eX- tensions B B (of the upright frames B B,

a part or all of its weight being carried by hydraulic rams or buffers K K as usual.

The die L (Fig. 5 or-16) is carried by the table or movable bed M which `slides on vertical guideways m m between the upright frame B B. Part or all of its weight as desired is carried by hydraulic rams or buffers N N as usual, these being located within the side frames B B and base A. v

Both the punch and /table derive motion from the crank shaft P through cranks, le-

vers, links and connecting rods, as will be described. The shaft'P may be driven in any suitable way, preferably through reduction gearing, as will be described. ln the construction shown the main shaft P-is mounted in bearings in rearward extensions of the side frames B B, being located considerably to the rear of the center line of the press, for reasons hereinafter stated. The shaft P carries on opposite sides cranks j) p from which both thepunch and table are driven. These cranks are conveniently formed as studs fixed in gear-wheels B P keyed upon opposite ends of the shaft, and

through Awhich gear wheels the shaft is driven.

`For driving the punch the cranks p p connect through rods or links Q Q with rock levers R R on oppositesides of the press,

which levers in turn connect through rods or links S S to the pivotal ends j y" of the cross head J. The connection between the levers R and rods S is made by means of pivot pins s which are-adjustable toward or from the fulcrum pivots R ofthe levers for the purpose of imparting a variable stroke to the punch. The detail construction vfor permitting this adjustment maybe greatly varied, but in that shown the wrist pin s has "square heads s which slide in opposite grooves r formed in a channel portion of the lever, wedges 1 being provided for taking forced into holes drilled partly inthe metal of the lever R and partly in the heads s',

additional holes being bored in the lever -for each adjustment of the wrist pin. The pins s2 are preferably tapered screw 'pins or plugs. To enable the connecting rods S, le-

vers R, and wrist pins s to be assembled, the connectingrods are each made with a loop or 1stirrup S at its` lower pivotal end (see Fig. 6), having an opening lar e enough to permit the head s to be passe through wit; this opening being filled by a block S2 tightened by a wedge s3 driven in above' .it and held 'by a screw clamp s4 and 8).

Themovements ofthe table M are imparted from one (or both) Aof the cranks p through a succession of connecting links and toggles coperating to impart tothe table when in its elevated `or blank-holding posit-ion the prolonged dwell which is necesarm of a rock lever U. To the opposite arm,

of this lever U is jointed a link U, this arm and link constituting a second pair of toggles the opposite end of this link U is connected toa ycrank arm V fixed on a transverse shaft V which has bearings in the base frame A, and to which is keyed the prolonged hub 1V being adjustable inlength to vary the movement of the bed. To this adjustable arm is jointed a link (or preferably a pair of links as shown) t, connecting to a lever -X,t-he

of a lever arm W, this arm.

(Figs. 6

frontend of which is fulcrumed at arto the" base A, and its rear end is jointed to a link X, so that X and X constitute together a third pair of toggles. vThe other end'of the link X is jointed to an arm Y (or pair of arms) projecting from a`rock shaft Y, which is formed with two arms Z Z projecting from it, each of which is jointed to a toggle link Z the opposite end of which link is jointed to thetable M. Each arm Z and link Z constitute a pair of toggles. In order to support the table firmly four pairs ofthe toggles Z Z are provided, arranged having an arm y connected by a parallel.

motion link w with the arm Y so that the shafts Y and y .oscillate in unison, causing simult neous movements of the respective toggles Z Z and a z for raising and lowering the table M. Thus it is seen that between the crank 'p and the table M there are'- four Vsuccessive pairs of toggles, viz: (l)

the toggles T T ;l (2) the toggles U U; (3 the toggles X X; and (4) the-toggles Z'Z, and their mates. The relative arrangement of these togglesis important for the attainlowermost position.

ment of the prolonged dwell of the table in the blank holding position. The extent of this dwell and the movement 'of the bed and of the punch are shown in the diagram or time chart Fig. 15, wherein the heavy full lines show the movements of the table and punch respectively when adjusted for their maximum movements, the heavy dotted lines showing their adjustment to their mimmumv movements. l

As is usual'with drawing presses, the press is driven through a clutch by which the main or crank shaft is turned for one complete revolution at each operation and is stopped (either manually or automatically) at the end thereof. This stopping point should ideally be when the punch is fully raised and the table fully depressed, but as these positions cannot practically be realized in exact coincidence, the stopping point may occur at any time after the table 1s fully or nearly down and before the punch is fully up. It may for example be in the position occupied by the parts as shown inFig'. 11, in which the punch is at top stroke and the tablehas been elevated but little from its Starting therefore with the position shown in Fig. 11, we will follow the successive'movementsof the apparatus,taking first the .punch movements. In Fig. 11 as stated the punch is at top stroke, and -h'ence the crank 7) is on a radius alined with the center line of the connecting rods Q, that is to say, on its dead center. The relations of the 'crank shaft axis, crank i radius, flcrum axis or lever R, and the length ofthe long arm of this lever, are such witlithe proportions shown in the drawing that the crank has to move through an arc of 210 (approximately) in order to` bring the crank radius again into alinement sition being shown in dotted lines in Fig.'

with the middlev line of the connecting rod,( or to its opposite dead center corres onding to the lowest position of the punch this po- 11). It results therefore that the upstroke or idle movement of the punch is performed in the remaining 150 of the cranks rota- 14 inclusive.

agence tion. Thus thev down or working stroke of thepunch is so prolonged, and the upper idle stroke so accelerated, as `to create a dierence of' 60 in time between them. This relative timing of the` partsV may be varied by changing the proportions or relative arrangements of theA working parts. The

table movementsare less obvious because of tation of the crank, rapid ldescelding and.

ascending movementsLand during the other half of the cranks rotation is held practically motionless.

The table. movements .can best be traced I through the series of diagrams Figs. 11 to l For clearness. the duplicate toggles a z are omitted from these diagrains. Fig. 12 shows the parts when the table is in its lowermost position, thelink a.' being onv the upper dead center of the crank, and the toggle link T being (as shown-by the arc 1A)l at the upper end of its stroke. The toggle T T is consequently buckled, the lever U being at one extremity of its stroke as shown by the arcs 2 and 3. The toggles U U are also buckled, and the lever formed by arms V W is at one end of its stroke as shown by arcs 4 and 5. Consequentlythe toggle X X is buckled, (see arc 6) and so are 'the toggles,

Z Z (see arcs 7, 8) land their mates, so that their pivotal engagement .with the table is at the lowest point 9 (the highest point to whicl; the table is to be lifted being located at 10 In Fig. 13 the crank p has turned aboutv 62 or suflicient to brin the toggle arm T nearly to mid-stroke. Turing this movement lthe table has been completely lifted. This is due to the angular relation of the vsuccessive toggles, as will be seen by comparing Fig. 1a with Fig. 12. The link 'r' has pushed lever U to nearly the end of its stroke, thereby nearly straightening the togl Y gles U U', bringing the lever V W nearer the end of its stroke than is the lever U, and consequently so nearly straightening the toggle X X as to swing the arms Y Z into vertical position, thus straightening the table liftlng toggles Z Z and vlifting their pivotal connection with the table to the level 1'0.

In Fig. 14 the crank p has advanced about 33 farther or to the (point where the toggles T T are straightene thereby bring- 'ing the levers U, and V W to their extreme position, almost straightening the toggles their straight linev position to a flexure approximately equal but opposite to'that in Fig. 13. This'movement momentarily elongates the toggles X X and then shortens lU U and carrying the toggles X X past them again to their former length, but this variation imparts so little angular Amovement to the toggles Z Z and their mates that the difference in the length of' these toggles is so slight as not to appreciably affect the bite of the blank holding surfaces upon the blank or shell being drawn. lDuring the further movement of the crank p to the point 11 in Fig. 14, the toggle arm T is carried to the extremity `of its movement at point 12, thereby shortening the toggles 'l T, and drawing the connection of' the latter with lever U back tothe point 13; the lever U thus is rocked back to the position it had in Fig. 13, and all the following parts then reoccupy the positions shown in that figure. This movement again rocks the toggles X X past their alined position, thus lengthening and again shortening them to so minute an extent as not to ai'ect'appreciably the tog gles Z Z, which remain essentially alined. .The further movement of the crank from point 11 to point 14 (F ig. 14) re-alines thev toggles T T and brings all the succeeding parts back to the position shown in Fig. 14. This again throws theftoggles X X from one side of their alined position tothe other, but with the same negligible eii'ect upon thc toggles Z Z. The further movement of the crank p rompoint 14 to the point 15,-Fig. 13, (see dotted lines) restores the' toggles T T and-all the succeeding 4lappartus to the positions shown in Fig. 13. With this movement again the toggles X X rock across from one side of their alined position to the other, with the same negligible effect upon the toggles Z Z. The crank pin p in passing beyond the point 15 inL Fig. 13 further buckles the toggles T T until the position shown in Fig. 12 is again reached, and during this interval (a movement of about 100) the table is lowered to its iirst posil tion.

A To vary the working stroke of the pnch' connecting rod S toward or from the fulcrum point R. This is accomplished by. re-

moving the keys s2, slacking the wedges r', sliding. the wrist pin blocks in the grooves 1' to the required position, and reinserting the tapered keys and retightening the wedges. This adjustment must be made with exact equality for both levers R R, in order that bot-h ends of the cross head J shall be moved the same distance during the revolution of the crank.

The lever R is.shown as so shaped that this adjustment is made on a radius which is horizontal at about mid-stroke. Itfollows from this arrangement that the shortening of the punch. stroke by adjusting the joint toward R occurs equally on both sides of mid-stroke. The invention is not limited to this feature, as the construction might be such that the adjustment would not alter the upper, or lower, or any other desired portion of the punch or punch-slide. If the change of' punch-stroke alters the elevation of the punch, it is easy to effect a compensating readjustment of the height of the gages studs w2 projecting to opposite sides l from the slide fw. rThese .studs are on an axis considerably beneath the middle line bf the arm W, so thatthe axis is adjustable in a ldirection tangential to the axis of the shaft V', the purpose being to insure that the adjustment of the table shall not affect its elevated or blank-holding position. Hence the line of this-adjustment is approximately a level line when the table is elevated, being shown exactly level in the vposition-of Fig. 13. Considerable variance is permissible in the exact angle of this line of adjustment, provided the Jadjustment does not carry the toggles X X outside (or materially so) of the degree of deflect-ion (substantially that indicated in Figs. 13 and 14), which keeps the table-operating toggles Z Z vertically alined. Hence the effective length of the arm WV may be adjusted to vary proportionally the -rise and fall of the table without aEecting the uppermost position of the table, and lhence without aii'ecting the grip upon the blank exerted between the blank holding surfaces. The extreme adjustment is that indicated by the dotted line t in Fig. 13, and by the heavy dotted lines in Fig. 12, this adjustment diminishing the descent of the table to the extent shown by the latter lines, so that the lowest point instead of being` at 9 is at 16 in this ligure.

The modification of the pat-h of movement of the table is shown bythe heavy dotted line inthe diagram Fig. 15.

The blank holder, die and punch, will of course have any proportions necessitated by the Work being done, and will be supported seither directly upon their respective supports or through any required intermediate spacing pieces or bolsters, asis the well understood practice.v As the table rises -to an invariable height, the space between it and the equalizing ring orswivel plate E must be sufficient to receive the die and blank holder for the longest shell to be drawn; forf shorter shells the space may be filled or nearly so by interposing spacing pieces, or

. holsters, as shown in Fig. 16, which shows ioo the drawing of a shellof maximum diameter and minimum length from a fiat blank..

Such use of spacing bolsters avoids the necessity for excessivev adjustment of the blank-holder frame F for each different new die and' blank-holder. The punch -plunger H requires `to be adjusted vertically to accommodate the different lengths of punch to be used, and with reference tothe lowermost position of the punch, at the end of leach draw. Figs. 5 and 16 show two ad -justments for punches of widely varying 'lengths l For adjusting the blank-holder equalizingring vto different heights, thev blank-holder frame -F is made vertically adjustable, preferably by externally threading it and providing it with screwthreaded clamping rings or nuts f beneath and f above. ,By turning these rings the frame or cylinder F may be propelled up or down, being" held from rotation in any suitable manner. When adjusted to the desired height, either of the rings is rotated suiiciently to clamp the frame F fast, thus serving'as a lock nut. The rings f f may be turned in any convenient way, as for example by the means shown in Fig. 5, comprising pinions c e meshing with the respective rings, mounted on a.

Vplunger H may be made in similar manner.

This plunger is a screwthreaded shaft passing freely through the bore of the'lowerl member I of the punch-carrying crossshead,v

being splined thereto to prevent rotation.v

Adjusting nuts z' and i engage the plunger .and turn in recesses formed in the member I.. These nuts also maybe tumed in any sultable manner, and because of their inaccessibility it is necessary 'to provide special .mechanism for turning them. A sultable mechanism is that shown in Fig. 17 where# 1n the nuts'and gear teeth are engaged rej spectively by pinions z, k on a vertical shaft h2 whlch is carried by the members I JI of the punch slide, and which shaft-may be turned by a crank or gearing in any convenient way. One ofthe pinions z, or h must be detachably connected so that one of the nuts may be turned independently of the other forunclamping the plunger H before adjustment and reclamping it fast after adv justment, for which purpose any suitable clutch ha may be provided. In order that Athe lower nuts f and may carry the weight of the parts engaged by them, they are held @eases in place by flanges or rings f2 and 2 respectively,'these rings being fastened `in place to inclose the respective nuts.

The punch plunger -H 1s made as short as possible consistent with the range of vertical adjustment necessary, and to carry it with the unmost possible firmness, it is supported as described in the extension member I, and

,therefore considerably beneath the cross head proper J. This extension I makes a sliding fit withl the bored interior`of the blank-holder frame F, whereby it is accu- 'rately guided and the punch firmly centered.

When t-he punch plunger has to be adjusted to a considerable downward projection from the lmember I, it may be further supported by introducing temporarily a strut or brace piece, this being especially desirable when the punch is of large diameter. In Fig. 16 a vertically depending strut or reinforce shell c', has been introduced, projecting beneath the member I and engagmg the top of the punch, so as to steady apunch of large diameter against any tipping tendency due to t-he` excessive pressure on one side, or any lateral draggln effect due ,to an 'uneven grlp upon the b ank, or other cause.

The cross` head J is preferably of archA form as shown, to best transmit the down- Y ward pull of the rods S S against the 'upward resistance or reaction of the central punch plunger H. This arched form permits of forming Within it a central chamber J (Fig. 4) of sufficient height to permitthe extreme. upward .adjustmentx of the punch plunger without necessitating that-it pass up through the topv ofthe cross head?, ser that the'4 'upper iange d; of\the cross-head is kept imperforate and of maximum strength. The central thrust or reaction of the plunger is transmittedfto the crosshead through the extension member I, which has a coned body .portion whereby the thrust is transmitted outwardly anddistributed to the cross-head, thereby enabling the latter to bemade of considerably less weight than would be required if the same punch pressure were apn plied to it at its middle as heretofore.

For removing the drawn shells by lifting them out upwardly, it is common to usega stationary knock-out which 4as the table' descends stops the shell and holds it so that it is pushed out of the die by the descent of the table. This knock-out is shown at g (Figs. 4 and 5) and 'consists .of a plate held on a vertically adjustable column g supported on a cross bar g2 which at its ends is detachably connected to the side frames. When it 'is desired to remove the drawn shell from beneath the table, it is necessary to detach and take out the knock-out. y

The press may be driven in any suitable way,but preferably it is provided with a Variable speed gear betweenthecrank shaft and the source of power. This is best shown t shown) of pinions n, and the latter a corre-A in 2, where 1c is the'driving shaft to which power is applied in any suitable way,

as for example by a belt on a. pulley 7c', a ily-- wheel k2 being preferably applied and the power transmitted through a clutch Z of any suitable type, its driving member being fixed to the shaft Z:,vand its driven member sleeved thereon with a pinion Z driving a gear Z2 on a secondary shaft n, whichv in turn drives a third shaft o, which in turn through pinion o and gear o2 drives a fourth shaft g, which has pinions g meshing with the two gear Wheels P on the main or crank shaft P. The speed change gears are shown as introduced between the shafts n and o, the former carrying any suitable number (three being sponding number of gear n2, the respective pinions and gears being in different speed ratios, and either the pinions or gears being adjustable along the shaft in order to bring one or other of them into mesh according to the speed desired, this being in itself a common and well known arrangement of speed changing gear. The speed ratio may be so varied as to impart to the punch the' maximum permissible speed with a uniform speed of the motor, or it may be varied vto avoid excessive driving torque with heavy loads, or to operate the press at the maxiumm speed within the `power of the motor.

The swinging lever R is preferably not pivoted to the upright frame of the press, for the reason that the stresses upon its pivot during the drawing movement of the punch are exerted in an obliquely upward and backward direct-ion, the angle varying during the punch stroke and having, especially in the earlier part of the movement,

sufficient of a rearward component to exert an undesirable bending stress against the upright `frames, such as might spring the upright frames enough to throw the blankholder out of line. For carrying this stress, we provide a special frame` or frames consisting of posts or struts u u and tie bars rv v which converge at the fulcrumlstuds R and diverge to fixed connections with the heavy base A. The posts u u for each lever are arranged on opposite sidesof the gear wheel-P and are connected by a stirrup plate u2 bridging the gear wheel and having upwardly projecting ears coinciding with the terminal ears of the links 'v e: and embracking the fulcrum stud R. The ties v are arranged in pairs so as to balance the stress, and the lever R worksbetween them.

The crank shaft P is preferably located as shown to the rear of the center of the press, for several reasons. This location facilitates the essential arrangement of the crank axis relatively to the long arm of the lever R, whereby the quick return stroke of the punch is secured. It also removes the shaft P from beneath the table where its presence would prevent the removal of pressedthrough shells from beneath, as is sometimes desirable. Its rearward location also brings its bearings to the exterior of the frame,

where the shaft, bearings, cranks and gearing are readily accessible for inspection, adjustment and repair.

The interposition of the levers R for communicating motion from the cranks to the punch cross head, accomplishes a triple purpose :-(l) by the described co-relation between the crank and the arc described by` l0, each section having its own bearings, and I each. formed integrally 'with one of the crank arms y and one of the toggle arms z. The two shaft sections are united by a crank pin 2/2 (Fig. 4) forming the/joint between the arms y and linkm. This construction facilitates the assembling of these parts.

The arrangement of the table-operating parts partly inside or between the arms and partly outside, is advantageous. Theoutside arrangement ofthe toggles T T and connecting rod a and their relation to the crank circle, permit the table-operating mechanism to take motion from the crank pin p on this side of the press, so that the same crank pin serves -both for the punch motion andthe table motion, and avoids the necessity of cranking the shaft P. While it is necessary to duplicate the punch-operating mechanism so` as to carry the stresses symmetrically on opposite sides of the frame, this is not necessary with'the tableoperating mechanism, except for the toggles directly` supporting the table, which are placed between the upright frames as usual. A certain amount of spring is admissable and even desirable intherst toggles T T and U U', any spring in these or in the arm V and shaft V havingno effect toimpair the symmetry of the forces which lift and sustain the table, since the final toggles receive theirmotion from the middle of the shaft V, where it is preferably stiened by the prolonged and heavy hub WV. It results that between this hub W and the table the transmission is nearly rigid, while between this hu-b andthe source of motion at the crank pin p a relatively considerable elasticity is permitted. It is within our invention to locate the crank shaft P in other positions than shown, for example directly beneath the center of the press, as indicated in the diagram Fig. 18. This involves a rearrangement of the leversvR whereby their respective arms are 1 5v. In a drawing press, the combination brought more nearly\into line, the pivotal f with a' reciprocatin slide .for carrying the connection s with the rods S being substantially intermediate of the fulcrum It',

'and the joint engaging the connecting rods Q. The essential relation between the circle described by the crank center and the'arc -described by the long arm of the lever,

whereby the quick return stroke of the punch is secured,-is thus unchanged.`

The adjustmentl of thev effective length of the lever R need not' necessarily be along a radial line, and for some purposes it may be preferable to make it'along a tangential line, as shown for example in Fig. I9. The tangent may be such that the lower position of the punch-carrying slide may be unaiected by the adjustment of the punch stroke.'

The particular press illustrated is designed to sustain a blank-holding pressure amounting t0 siX hundred tons and a drawing or punch pressure of six hundred tons, making a total die-pressure carried by the table, of twelve hundred tons. These figures are given only as illustrative, as the invention is adapted to a wide range of sizes and pressures.

It must not beinferred from the particularity of detail with which we have described the preferred embodiment of our invention, that we are by any fmeans to be limited thereto, since our invention is susceptible'of 'a wide degree of modification Vwithin the skill of the engineer or constructor, and with reference to the particular work the machine is in any instance designed to perform.' The features of our invention'which `are believed to be novel are defined in the claims terminating this specication.

Weclaim as our invention y 1. In a drawing press, the combinationv with a reciprocating slide for carrying the punch, a reciprocatlng blank-holding table, and driving mechanism for said slide and table, of adjusting means for varying the stroke of said punch-carrying slide and of said table. y

2. In a drawing press, the combination ing the`y punch, of positive driving mechanismfor said slide adapted to reciprocate the slide more rapidly on its return or idle stroke than on its working stroke.

punch, a reciprocatmg blank-holding table,

and driving vmechanism for lsaid slide and table, ,of adjustingmeans for varying the stroke of said punch-carrying slide and of said table, and vspeed varying mechanism whereby when the drawing speed is changed 4by a lpunch stroke adjustment it may be .nient it may be compensated for by a speed adjustment to restore or partially restore the normal drawing speed.

7. In a drawingpress, the combination with a reciprocating slidefor carrying the punch, and driving mechanism for said slide, of adjustino` means for -varying the stroke of said slidne comprising aflever and means for varying the effective*- length thereof. 'I

8. In a drawing press, the combination?` with a reciprocating slide for carrying the punch, and 'driving mechanism for said slide, of adjusting means for varying the stroke 'of said slide comprising a lever, a

driving crank for rocking said lever, and a connection between said lever and slide, with means for varying the eifective length of said lever.

9. In a drawing press,the combination with a reciprocating slide for carrying the punch, and driving mechanism for said slide, of adjusting means for varying the stroke of said slide comprising a lever, a driving crank for rocking said lever, and a connection between said lever and slide, with means for varying the effective length of said lever by adjusting the distance of such connection from the fulcrum of the lever.

10. In a drawing' press, the combination with a reciprocating slide for carrying the punch, and' driving mechanism for said slide, of adjustingl means for varying the stroke of said slide comprisinga lever and K means for varying the effective length thereof consisting of av pivotal stud -land means for adjusting the same to varying distances from the fulcrum of the lever.

1l. In a drawing press, the combination with a reciprocatingslide 'for carrying the punch, and driving mechanism for said slide, of adjusting means for varying th' stroke of Ysaid slide com rising a lever and means for varying the e ective length thereof, said lever formed with a slideway, a vpivpunch, and driving mechanism for said slide, of adjusting means for ,varying the strole of said slide comprising a lever form d with a slideway, a pivotal stud adjustable in said slideway, and a key for fastening said stud after adjustment. Y

13. In a drawing press, the combination with a reciprocating slide for carrying the punch, and driving mechanism for said slide, of adjusting means for varying the stroke of said slide comprising a lever formed with a slideway, a pivotal stud adjustable in said sldeway, and a wedge for tightening said stud in said slideway after adjustment.

14. In a drawing press, the combination with a reciprocating slide for carrying the punch, and driving mechanism for said slide, of adjusting means for varying the stroke of said slide, comprising a lever, a connecting rod, and a pivotal stud uniting them, said stud adjustable toward or from the fulcrum of the lever .and having an enlarged head, and a connecting rod formed with a stirrup having an enlarged opening to admit such head, and a filling piece for closing said opening.

15. In a drawing press, the combination with a reciprocating slide for c arrying the punch, of driving mechanism for said slide comprising a crank and connecting rod, the crank arranged to operate at a greatermechanical advantage during the working stroke of the punch and at a lesser advantage during the idle or return stroke thereof.

16. In a drawing press, the combination with a reciprocating slide for carrying the punch, of driving mechanism for said slide comprising a crank, a lever oscillated therey, and a connecting rod connected to said lever relatively arranged to operate at maximum mechanical advantage during tho working stroke of the punch, and at mini mumadvantage during the idle stroke thereof, whereby the punch is given a relatively rapid return movement.

17. In` a toggle drawing press, the combination with the reciprocating blank-holding table and driving mechanism therefor, of adjusting means for varying the retractile stroke of said table without affecting its blank-holding position.

18. Ina toggle drawing press, the combination with the reciprocating blank-holding table, of driving mechanism therefor comprising a lever arm through which motion is communicated to the table-operating toggles, and means for adjusting the eifective length of said lever arm to vary the stroke of the tablef l 19'. In a toggle drawing press, the combination with the reciprocating blank-holding table, of driving mechanism therefor comprising a lever arm through which motion is communicated to the table-operating toggles, and means for adjusting the effective length of said lever arm to vary'the stroke of the table, such adjustment bein in such direction as position of said toggles when straightened,

not to alter the effective i whereby the blank-holding position of the l.

table is not varie i v 20. Inav toggle drawing press, the combination with the reciprocatingblank-holding table, of driving mechanism therefor comprising a crank, toggles connected to said crank to be buckled thereby during one semi-revolution and vibrated thereby to opposite sides of their alined position during thesecond semi-revolution, a second pair of toggles vibrated by the first with a diminished amplitude ofmovement during' such second semi-revolution, a third pair of togv gles vibrated from the second, and the final or table-operating toggles vibrated from such third toggles, said parts operatively related to essentially eliminate the motion of said final toggles and holdthe table stationary during approximately said second semi-revolution, thereby insuring a blank holding dwell approximating 180 degrees of the rotation of said crank.

21. In a toggle drawing press, the combination with parallel side frames and a reciprocating blank-holding table moving between said frames, of driving mechanism therefor comprising a crank, successive toggles interposed between said crank and table, the primary toggles and their connection with said crank arranged outside said frames, the final or table-operating toggles arranged between said frames, and a rock shaft extending partly outside and ,partly between said frames for communicating motion between said outside toggles and said final or inside toggles.

22. In a toggle drawing press, the com-l bination with parallel side frames and a reciprocating blank-holding table moving between said frames, of driving mechanism therefor comprising a crank, successive toggles interposed between said crank and table, the primary toggles and their conneet-ion with said crank arranged outside said frames, the final or table-operatmg toggles arranged between said frames, a rock shaft extending between said frames receiving. motion from said primary toggles. and having a lever armvwith means for adjusting its effective length, and a connection from said arm to said final or inside toggles.

23. In a toggle drawing press, the comv for arranged in pairs, those of one pair con-

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