US739378A - Drawing-press. - Google Patents

Description

I PATENTED SEPT. 22, 1903.-

0.8.BEYER. DRAWING mass.

APPLICATION FILED JUNE 6, 1902.

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PATENTBD SEPT. 22, 1903;

- 0. s. BF-YER. DRAWING PRESS. A'rrmoumn PIL DIJUM s, 1902 3 SHEETS-SHEET 3.

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WITNESSES:

THE mums l'EfERs co. PHOTO-LITHCL. wAsnmuTou. u u,

\ UNITED STATES Patented September 22, 1903 PATENT OFFICE.

OTTO S. BEYER, OF CARLSTA-DT, NEW JERSEY, ASSIGNOR TO E. W. BLIS S COMPANY, OF BROOKLYN, NEW YORK, A CORPORATION OF WEST VIR- GINIA.

DRAWING-PRESS.

SPECIFICATION forming'part of Letters Patent No. 739,378, dated September 22,1903. Application filed June 5, 1902 Serial No. 110.325. (No model;)

To all whom it may concern:

Be it known that I,.O'J.TO S. BEYER, a citizen of the United States, residing at Carlstadt, in the county of Bergen and State of cup-shaped articles. Such presses require an annular blank-holder for pinching the rim portion of the blank with a suitable graduated pressure and a punch or male die movable through the blank-holder for forcing the central portion of the blank into cup shape and drawing the metal between the blankholding surfaces. Two types of such presses are commonly used-namely, first, the American type, where the bed or lower die is stationary and the blank-holder descends from above it, while the punch also descends from above through the blank-holder and through the female die, and, second, the German type, wherethe upper blank-holding member is stationary and the lower member or die is mounted upon a bed or platen which. moves up from beneath to clamp the blank against the blank-holding member, while the punch comes down from above through the blankholder and into thedie to draw the blank. In both typesof press it is common to use toggle-joints as the means for operating the movable blank-holding member, the toggles straightening or moving into alinement at the instant that the blank is clamped against the stationary member. In both types of press it is common to drive the punch from a crank which executes one revolution to each drawing operation. The blank is clamped at about the beginning of the downstroke of the punch and is held with the requisite pressure during this stroke, being released immediately after the punch-operating crank passes its lower dead-center, whereupon the movable blank holding member separates from the stationary member to enable a new blank to be placed in position to be drawn.

' In feeding on a new blank it is placedon the die or lower member of the blank-holder. In

the American type of press, as this die is sta tionary, it is only necessary that the upper sufficient time to enable the blank to be properly placed in position. To this end it is common in the German type of press to provide that the movable bed which carries the die shall remain stationary in its lowest position during-about one hundred and twenty degrees; that it shall then ascend during about sixty degrees, during which time the punch'begins its descending movement; that it shall then remain stationaryin the blankholding positionduring about one hundred and twenty degrees, while the punch descends through it to draw the blank, and thereupon that it shall descend during about sixty degrees to its original position. These intermittent movements of the die have usually been imparted by means of a cam or cams, either directly or through the medium of toggles; but such use of cams has usually been disadvantageous because of the long stroke required, so that either an extremely largecam must be used or else the motion must be multiplied through levers, and the efieots ofwear of the cam-surfaces have been detrimental in a machine requiring such ex actness of operation and the expenditure of such power as are necessary in a drawing press. p

My invention provides an improved means for operating the movable bed or other movable part carrying the movable member of the blank holder. I may employ togglejoints or any other known or suitable mechanism for directly imparting to the movable bed its up and down movements. For driving this mechanism I provide a crank (which may be and preferably is mounted on the main. shaft or crank-shaft which operates the punch) by which is imparted the long stroke or vertical movement necessary for correctly operating the bed, and in order to provide for a prolonged dwell of the bed at either or both extremities of its movement I provide means for modifying the throw impartedby the crank to such effect that while the crank is passing through that part of its movement adjacent to one (or both) of its dead-centers (and preferably for about sixty degrees preceding and sixty degrees succeeding its dead-center) no movement shall be imparted to the bed. lVhen the usual compound toggle-joint mechanism is employed for driving the bed, the lost motion which is taken up in the toggles and operating-links is ordinarily sufficient to provide the requisite dwell during the upper or blank-holding position of the bed, so that ordinarily no modification of the crank movement is necessary to provide for this dwell; but to provide for the dwell in the lower position of the bed I provide for suitably modifying the effect of the movement which would otherwise be imparted by the crank, and to this end I employ, preferably, a cam, which has the elfectof nullifying or neutralizing that portion of the thrust corresponding to the movement of the crank adjacent to its dead-center.

My invention may be variously applied, as will be indicated hereinafter.

Figure l of the accompanying drawings is a side elevation of a drawing-press embodying my invention. Fig. 2 is a front elevation thereof, the blankholding dies being shown in section. Fig. 3 is a horizontal section thereof, taken approximately on the line 3 3 in Fig. 1. Fig. 4: is a fragmentary vertical section of the upper left-hand portion of Fig. 2. Fig. 5 is a diagram illustrating the relative movement of the punch and lower die or bed. Fig. 6 is aside elevation of Fig. 1, showing a modification. Fig. 7 is a similar side elevation showinganother modification. Fig. 8 is a fragmentary view showing a modification of the cam 'l of Fig. 1.

Referring to the drawings, let A designate any suitable frame, preferably upright and consisting in the construction shown of two upright side frames connected together attop and bottom and having a stationary crosshead B fixed in place between them. This cross-head is vertically adjustable by means of screws or bolts a a, connecting it to any suitable part of the upright side frames. A vertically movable slide or plunger G is mounted to move through the open or hollow central portion of the cross-head B. A lower cross-piece D, constituting a movable bed or platen, is mounted to move vertically between the side frames, being guided by any suitable slideways. The cross-pieces B and D carry, respectively, the clamping members, which together constitute the blank-holding means, the upper blank-holding member E being fastened beneath the cross-head B while the lower blank-holding member F is fastened on top of the movable bed D. The punch G is fastened beneath the plunger 0 and works through the blank-holding mem bers E F, the latter of which constitutes, as

usual, the female die. The vertically-reciprocating plunger '0, with its punch Gr, may be moved by any mechanism known in the art or applicable to this purpose, being shown as operated by a crank H on a shaft H, the plunger being connected to the crank by a suitable connecting rod or pitman I, which may be adjustable in length, as usual, in order to adjust the punch up or down. This crank-driving mechanism imparts a regular rising and falling movement to the punch, as shown by the sinuous curve in Fig. 5. Ordinarily the press will be driven continuously, although my invention does not exclude the provision of means for stopping the machine at the end of each complete revolution, so that it shall remain inactive until again started by the operator.

The bed D may be caused to ascend or descend by any known or suitable mechanism, toggle-joints being preferable. In the construction shown toggle arms or links J J are jointed at their upper ends to the bed and at their lower ends to toggle-arms K K, projecting from shafts L L, Fig. 3, which shafts have bearings in the side frames, and at one side of the machine these shafts extend through the side frames and have arms L on their ends, which arms are jointed to links M M, which in turn are jointed to a vertically-movable slide P, which is guided on slideways P on the side frames. Theslide P is shown in Figs. 1 and 2 in its lowermost position. In this position the links M M are approximately vertical and parallel, and the toggle-joints J K are folded together or collapsed, so that the bedD is drawn down. As the slideP is pushed upwardly it communicates an upward thrust through the links M M to the arms L L, so that an oscillatory motion is communicated to the shafts L L, whereby the toggle-arms K K are swung from the position shown upwardly until they reach an approximately vertical position, an upward thrust being communicated from them through the togglelinks J J to the bed D. The parts stop with the toggles J K extended in substantial alinement with one another, so that the bed D is supported by the four toggle-links J J and the toggle-arms K K, so that the strain incident to the required pressure for holding the blank is communicated through the alined toggle-links and arms to the shafts L L adjacent to the bearings of these shafts in the side frames. At the instant that the toggles J K are in line the links M M have swung around to a position approximately horizontal, and consequently perpendicular, or nearly so, to the toggles. Hence in approaching this position the links act with a very great mechanical advantage as the final pressure is applied in clamping the blank, and the relatively considerable movement of the slide P results in so infinitesimal a movement imparted to the bed D as to have no appreciable effect upon the blank-holding or clamping function of the bed. The bed-operating mechanism thus far described. is the well-known compound toggle movement commonlyused for operating the blank-holder in drawing-presses of the American type, and forms no novel part of my invention. It may be substituted by any other mechanical movement, for imparting the rising and falling movements to the bed under control of the mechanism which I will proceed to describe.

For imparting motion to the bed-operating mechanism-that is to say, with the specific bed-operating mechanism shown to the slide P thereof-I provide a crank Q upon the main driving-shaft H, which may be, as shown, setat an angle of about ninety. degrees behind the crank H or at other suitable angle, and,

.of this link carrying a roller S, which travels in the groove of a cam T, while to the link R, and preferably at a point coincident with the center of roller S, is jointed a connecting-rod U,,which extends downto and engages the slide P. If the connecting-rod U were .con-

nected directly at its upper end to the crank-.

stud Q obviously, a regular rising-and-falling motion would be imparted to the slideP, suchas that indicated by the sinusoidalcurve inxFig. 5, which indicates the movement of the punch. This would cause the. bed to dwell in its uppermost position, because of the lost motion due to the interposition of the compound toggle movement; but the bed would not dwell in its lowermost position. To cause such dwell of the bed when it is down is the function of the link R and cam T, by which the crank movement is modified and a dwell is introduced corresponding to the lowermost position of the slide P, and hence ofthe bed D. The groove of the cam T follows a circular path (which. may coincide with that of the crank-stud Q, as shown, or may differ'therefrom inradiuslfor approximately two-thirds of a revolution, while for the remaining portion, or third of a revolution, it follows an arc 00 w struck from the center of the stud b, by which the connectingrod U is jointed in the slide P. Hence as the crank Q drags the link R around the roller S of this link, traveling in the'camgroove T, follows a circular path until it reaches the lower part T of the cam, and in passing through this portion it swings across at a uniform distance from the center b, and

consequently without communicating any motionto the bed, since the rod U during this time is caused simply to swing around the center I). Thus for a period preceding :1 and succeeding'the passage of the lower deadinvention provides a combination of a crank were made of excessive size. is not subject to much wear, and in case itand cam for operating the bed, whereby'the' long. throw necessary forv imparting the requisite rising-and-falling movement to the bed is derived from the crank, while the variable movement necessary to give the requisite dwell to the bed is imparted by the cam.

This construction has the advantage that it is not necessary to interpose a lever or other means of multiplying the motion, as would be necessary if a cam were provided for'imparting the entire movement, unless such cam The cam shown 1 wears-the effect of the wear is not multiplied;

but byreason of the action of thecompound toggles the effect of any ordinary wear'upon the blank holding or clamping operation is v practically nullified, and when the bed is in its lowermost position any slight irregularity of movement due to wear of the cam would be of no consequence.

The relative movements of the punch and of the bed carrying the lower die are-indicated in Fig. 5. The bed begins to ascend shortly before the punch reaches the upper limit of its movement, and for a short time the bed is rising and thepunch is simultaneously descending. The bed stops in its. uppermost position shortly before the punch strikes the blank,so that the blank is clamped, and thereupon the punch encounters it and forces it down through the die. When the punch reaches the lower extremity of itsmovement, having drawn the blank out from between the blank-holding surfaces, the bed is caused to descend, whereupon the bed remains in its lowermost position for a sufficient time to enable a new blank to be put in place ..while the punch is ascending.

My invention may bevariously modified without departing from its essentialfeatures. One modified construction is shown in Fig. 6. In this figure the crank (here lettered Q instead of connecting with the connecting-rod through a link connects with it through 'a lever R the crank-stud Q engaging it at. its

middle, wh'ile'at the end of one arm it carries the roller S ,which travels in a cam-groove T and at the end of its other arm the lever is jointed to the connecting-rod U. The construction of the slide P and the compound toggle mechanism for transmitting movement to the bed is the same as before described.

The cam T is so shaped thatthe center of the stud c-traverses preciselythe same path or orbit that is traversed by the roller S and stud c in Fig. 1-that is to'say, a path which for about two-thirds of the circle is circular and for the remaining portion of the circle follows the arc 00 at, concentricwith the center b.

IIO

Another modification is shown in Fig-i7, Here the crank Q connects through a'rod V with a lever R one end of which is ful jointed at its outer end to a connecting-rod U the lower end of which is connected to the slide P. The stud d is engaged in a slot 9 in a guiding-bracket. During the greater part of the revolution of the crank Q the stud d is stationary in the upper end of the slot where it is held by the concentric portion of the cam T Hence the motion of the crank Q is communicated through the lever R and rod U to the slide P. When, however, the latter reaches its lowest position, the further movement of the crank is taken up in the lever R which moves down to the position shown in dotted lines under the action of the cam T In case a longer dwell of the bed in the blank-holding position is desired or in case some other bed-operating mechanism is used than the compound toggle mechanism herein described it is within my invention to so construct the cam as to provide a suitable dwell when the bed is in its uppermost position in addition to the dwell already described when the bed is down. This is illustrated in Fig. 8, where the cam T is the same as that shown in Fig. 1, except that in addition to the areshaped portion 00 w, concentric with the center I), it has an additional arc-shaped portion x m, concentric with the center I), which is that of the center I) in the uppermost position of the slide P or its substitute.

My invention is not necessarily limited to a drawing-press of the German type, since it is applicable, although with less advantage, to a press where the lower blank-holding me mber is stationary and the upper member is carried by a moving part, in which case the moving part carrying the upper member becomes the equivalent of the movable bed of the press herein described.

I claim as my invention 1. In a drawing-press, the combination with a movable bed, of a crank and pitman for op erating it, and means for neutralizing the effeet on the pitman of a portion of the vertical movement of the crank, whereby to cause the bed to dwell in its extreme position.

2. In a drawing-press, the combination with a movable bed, of a crank and pitman for operating it, and a cam for neutralizing the effect on the pitman of a portion of the vertical movement of the crank, whereby to cause the bed to dwell in its extreme position.

3. In a drawing-press, the combination with a movable bed, of a crank for operating it, and a stationary cam adapted to modify the vertical movement of the crank to cause the bed to dwell in its extreme position.

4. In a drawing-press, the combination with a movable bed, of a crank for operating it, a stationary cam, and a movable part interposed between the crank and bed and carried around by the crank in engagement with said cam, the cam being adapted to cause the movement imparted from the crank through the said movable part to the bed, to be modified, to cause the bed to dwell in its extreme position.

5. In a drawing-press, the combination with a movable bed, and operating mechanism for raising and lowering said bed, said mechanism comprising a vertically-movable slide, of a crank and pitman for reciprocating said slide and means for neutralizing the effect on the pitman of a portion of the vertical movement of the crank, to cause the bed to dwell in its extreme position.

6. In a drawing-press, the combination with a movable bed of a crank for operating it, a

OTTO S. BEYER.

WVitnesses:

WILLIAM KLOCKE, OTTO CI-IERDRON.

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