US2071001A

US2071001A - Sheet metal press

Info

Publication number: US2071001A
Application number: US28324A
Authority: US
Inventors: Fredrich J Rode; Meredith R Hatch; Arthur H Schloz
Original assignee: Individual
Current assignee: Individual
Priority date: 1935-06-25
Filing date: 1935-06-25
Publication date: 1937-02-16
Anticipated expiration: 1954-02-16

Description

Feb. 16, 1937. F. J. RODE ET AL SHEET METAL PRES 5 Filed June 25. 1955 6 Sheets-Sheet 1 Juan nib w. (2% e) 1/ @500 all):

Feb. 16, 1937. F. J. RODE ET AL 2,071,001

SHEET METAL PRESS Filed June 25, 1955 6 Sheets-Sheet 2 Feb. 16, 1937. F. J. RODE ET AL SHEET METAL PRESS 6 Sheets-Sheet 3 Filed June 25. 1935 Hg i- Skim/MA;

Feb. 16, 1937. F. J. RODE ET AL 2,071,001

SHEET METAL PRESS Filed June 25, 1935 6 Sheets-Sheet 4 Z 46 69 z 6 I II LE5 L 1 F i: as 45 i L 44 48' l 62 E; .i

ll I as 62 51 45 16 2'3 As HQ G o HqS Juana tom Mm "12 922m I4 Wet,

Feb. 16, 1937. F. J. RODE ET AL 2,071,001

SHEET METAL PRES 5 Filed June 25, 1935 6 sheets-Sheet 5 3 v 14) c wtouk Patented Feb. 16, 1937 PATENT OFFICE SHEET METAL PRESS Fredrich J. Rode, Meredmi'a. Hatch, and Arthur H. Schloz, Toledo, Ohio 7 Application June 25, 1935, Serial No. 28,324

87 Claims.

Our invention has for its object to produce a press having one or more work-engaging elements actuated by a shaft driven member that is caused to vary in its movements to produce desired timed movements of the element or elements.

The invention eliminates the use, in large sheet metal presses, of a large number of parts commonly required to produce sequential plunger engagement. It provides a shaft connector that is moved to accentuate and retard the movements of the plunger-operating means to produce desired movements of the plungers in timed relation and thus greatly reduces the number of forcetransmitting elements required to obtain desired plunger movement in presses.

More particularly the invention provides a master connector for connecting the force-transmitting elements that operate one or more sheet metal engaging plungers to a shaft and means for producing desired characteristic translatory and rotatory movements of the part or parts of the connector to which one or more of the said elements are connected, as the connector is moved by the rotation of the shaft, the said characteristic movements being translated by the force-transmission means to produce desired plunger movement during work engagement and withdrawal.

The invention also provides a pair of drive shafts and a pair of connectors to which the drive shafts are eccentrically connected, the forces that actuate the plungers diverging through the power transmission means from the connectors whereby each plunger is operated by the connectors to accentuate the movements of the plungers and control the length of their metal-engaging and metal-holding periods to enable flow of metal as the plungers sequentially engage, draw, and

redraw the metal and subsequently withdraw from their sheet metal engagement.

The invention also provides transmission of allactuating forces through oscillating or rotating members as distinguished from members that have sliding contact between surfaces of parts that move in different directions, as in the case of cams and the like. It eliminates transmission of forces through relatively sliding contacting surfaces other than contacting cylindrical surfaces. It produces a structure wherein the actuating forces between the movable elements of the press are transmitted entirely in directions located in parallel planes.

The invention also provides means for so disposing all force-transmitting parts that the actuating forces and corresponding reactant pressures are symmetrically distributed with reference to central longitudinal and transverse planes of the machine, thereby eliminating or reducing vibration and enabling duplication of parts located on opposite sides of the central transverse vertical plane.

The invention consists in other features which will appear from the following description and upon examination of the drawings. Structures containing the invention may partake of difierent forms and may be varied in their details and still embody the invention. To illustrate a practical application of the invention, we have selected a sheet metal press as an example of the various structures that contain the invention, it being understood that certain features of our invention may be used to advantage without a corresponding use of other features 01' the invention'and without departing from the spirit of the invention as presented in the claims. The particular structure selected is shown in the accompanying drawings.

Fig. l of the drawings illustrates a front view of the sheet metal press. Fig. 2 is a view of a vertical longitudinal section of the press. Fig. 3 is a perspective view of a master driving con: nector and shows the connection of parts of the press through which the forces that actuate two of the plungers are transmitted. Fig. 4 is a view of a section taken on the plane of the line 44 indicated in Fig. 2. Fig. 5 is a view of a central vertical transverse section of the press. Fig. -6 is a view of a section taken on theplane of the line 6-6 indicated in Fig. 2. Fig. '7 is an end View of the top part of the press. Fig. 8 is a view of a section taken on the plane of the line 8-8 indicated in Fig. 5. Fig. 9 illustrates diagrammatically and in a dimensional ratio several times larger than that in which the parts of the press are shown in the other figures, the curvilinear line described by the point on the connector through which the forces are transmitted in operating one of the plungers. Fig. 10 illustrates diagrammatically the relative movements of the plungers as measured in the rotation of each machine drive shaft oi the press and the movements of the points of the connector through which power is transmitted to two of the plungers during the periods of the work-engaging dwells of the plungers.

The sheet metal shaping press selected for the purpose of illustrating an embodiment of our invention has for its purpose to produce relatively deep drawing of large sheet metal parts and of necessity is exceedingly ponderous. When the press has a greater horizontal longitudinal dimension than the horizontal transverse dimension. the main driving shaft. the machine drive shafts, and the counter shafts that rotatably interconnect the main drive shaft and the machine drive shafts extend transversely and are supported in bearings located in or on the sides of the crown of the frame of the press. The machine drive shafts" are eccentrically connected to master connectors to which are connected plunger-operating means at different points on the connectors. The means for operating each plunger comprises a plurality of sets of pin machine drive shaft is applied to each of the drive shafts from which the rotative movements are translated into the oscillatory movements of each of the plunger-operating means to produce the reciprocatory movements of the plungers.

The main drive shaft 1 is rotatably supported in the crown 2 of the frame, and a motor may be connected by a suitably controlled clutch with the shaft I for operating it. The main drive shaft I is provided with a pinion 4 that meshes with the gear wheel 5 located near one end of the shaft 6 which is rotatably supported in bearings located on the upper edge portions of the sides of the crown 2. The gear wheel 5 meshes with the idler I, which is supported on the shaft 8. The gear wheel I is dimensionally the same as the gear wheel 5 and rotates in a direction opposite to that in which the gear wheel 5 rotates. The pinions 3 are located on the shafts 6 and 3 and mesh with the gear wheels 40 located on the shafts il. Pinions l2 are located on the ends of each of the shafts II and mesh with the gear wheels II. The pinions I2 and the gear wheels 13 are located on the outside of the crown 2. The gear wheels l3 are connected to the ends of each of the machine drive shafts I4 and IS. The machine drive shafts l4 and ii are thus rotated in opposite directions. In the machine selected as an example, the machine drive shafts are about thirteen inches in diameter and are supported in suitable bearings located in close proximity to the tie rods that secure theparts of the frame together. The frame of the machine consists of the crown 2, the

uprights

20 and 2|, and the base 22, which are tied together by means of the tie rods 23 that extend through the parts of the frame and are headed by suitable nuts for tightly securing the parts of the frame together and whereby all vibrations and stresses occurring by reason of the performance of the machine are efllciently sustained.

The machine drive shafts H and i5 operate a plurality of sets of pin-connected oscillatable elements that by their relative movements reciprocate three sheet metal engaging plungers which are slldably supported and guided by suitable ways formed in parts of the frame, one of the plungers being located for telescopic and slidable movements with the other of the plungers which is guided in its sliding movements by the uprights 20 and 2i of the frame. The remaining plunger is located within the base 22 and is guided in its sliding movements by suitable ways formed therein. The link-interconnected rocker members that form parts of the sets of oscillatable elements that operate the upper plungers are supported in the crown 2 by means of shafts either secured or rotatably supported in the sides of the crown; and the rocker members that operate the lower plunger are supported on fixed shafts that are secured in the sides of the base 22. Thus, all the supporting shafts ofthe machine and connecting pins of the oscillatable elements extend transversely with respect to-the press, and the forces are transmitted from element to elementin parallelplanes, producing the same actuating forces and reactant pressures in each of the vertical four quarters of the machine.

The sets of oscillatable elements terminate in suitable adjustable connections with the plungers that may be adjusted to produce accurate location of the plungers and the dies carried thereby with reference to each other, the work, and the guideways and produce free sliding movement of the plungers and accurate disposition of parts of the surfaces of each of the dies relative to the corresponding or registering or coacting parts of others of the dies.v The plungers are provided with suitable pneumatic or hydraulic loading means for cushioning the plungers in their operations and maintaining the interconnections of the oscillatable elements with the plunger and the drive shafts in close rotating contact to eliminate play as between the sliding cylindrical surfaces of thebaring and interconnecting parts of the oscillatable elements.

The machine drive shafts l4 and ii are eccentrically connected to the master connectors 23. The machine drive shafts are of the form of crank shafts and are supported in bearings 23 located at the ends of the crown 2 and closely positioned with reference to the cranks 21. The gear wheels I3 are keyed to the ends of the machine drive shafts and are located at the sides of the end parts of the crown and in closely positioned relation to the outer ends of the bearings.

The master connectors 28 are connected to sets of oscillatable elements through which the power of the drive shafts is transmitted to the ends of each of the plungers 30, 3|, and 32. The plunger 30 is slidably supported in suitable guides formed in the

uprights

20 and 2|, while the plunger 3| is slidably supported within the plunger 30 and is guided therein for telescopic movements relative thereto by suitable guideways located within the plunger 30. The lower plunger 32 is slidably supported within the base 22 and is guided by suitable ways formed within the base.

The plunger 30 is a sheet metal holding plunger, and the plungers 3| and 32 are sheet metal shaping plungers. (Fig. 2.) The plunger 30 is provided with a suitable sheet metal engaging die 33 of the type well known in the art for engaging the sheet metal at its edges to enable the drawing and shaping of the central areas thereof by the die 3|, which is connected to the upper sheet metal shaping plunger 3|, and the die 35, which is connected to the sheet metal shaping plunger 32. The top of the base 22 forms a bed on which is located the die 36 that coacts with the sheet metal holding die 33 to hold the metal peripherally as the dies 34 and 35 and the central portions of the die 30 coact with each-other to produce the desired configuration of the sheet metal, the plungers being so operated as to produce progressive engagement of the metal and enable the sheet metal to adjust itself to the extended draw that is produced by the operation of the press.

The plungers are withdrawn substantially simultaneously. The upper sheet metal shaping plunger u'rl is withdrawn more rapidly than the other plungers, and its die 34 frictionally operates to loosen the sheet metal as it is released by the other plungers. Thus, the sheet metal may 4 be readily manually lifted from the die 28 located on or forming a part of thebed of the press.

The master connectors 28 operate to produce such change in rate in the parts of the reciprocatory movement of each of the sheet metal shaping plungers as to enable sequential plunger engagement and gradual deformation of the metal from its planular shape and afford opportunity for the metal to flow" and set in its finally shaped configuration, and then cause the plungers to loosen the formed sheet metal from the dies by the relative withdrawal movements.

The connectors 28 are in the form of relatively short blocks, recessed to receive, or formed to enter, closely positioned oscillatable elements through which plunger-operating forces are transmitted. The connectors are provided with suitable pins for pivotally connecting the connectors to the oscillatable elements. Each of the pair of pins that connect each plunger-operating means with the connector are located in corresponding positions on the connectors. At two points separated substantially as measured in the rotation of the machine drive shafts, the central major axes of the connectors are inclined to the vertical substantially the same number of degrees, as shown in Figs. 1 and 2. These are the extreme positions in the reciprocatory movements of the connectors, and during the change from one position to the other, the three plungers perform their non-working strokes. During this movement, each connector is rotated or tilted slightly inwardly with respect to the center of the machine, then translated or bodily moved laterally towards the vertical transverse central plane 'of the machine, and then translated downwardly substantially in the direction of the major axis of the connector and again rotated or tilted outwardly to the position shown in Fig. l. The connector is then markedly rotated or tilted outwardly and then translated or moved bodily upward in a direction inclined to its major axis and while the angle of the tilt of the major axis of the connector to the direction of the bodily upward movement is maintained substantially constant. The connector is then rotated or tilted inwardly to the position shown in Fig. 2. During these reciprocatory and tilting or oscillatory movements of the connectors, the points of connection of the plunger-operating means with the connectors perform oscillatory and reciprocatory movements in the same direction during a, part of the rotation of the machine drive shafts and in opposite directions during another part of the rotation of the machine drive shafts and thereby produce increased and decreased rates of parts of the movements of the plungers in their des'red recurrent order.

The machine drive shafts l4 and I5 are rotated in directions indicated by the arrows shown in Fig. 2 and are eccentrically connected to the upper ends of the connectors 28 by the crank pins 21. The other ends of the connectors are connected by the pivot pins 40 to the plunger operating means that operates the upper plunger 3| and by the pivot pins 4i to the plunger-operating means that operates the plunger 30 and by the pins 42 to the plunger-operating means that operates the lower plunger 32. The centers of the pins 4| are located substantially in lines at right angles from the lower ends of the lines that extend from the centers of the crank pins 21 to the pins 48. The centers of the pivot pins 42 are located in lines extending at right angles to the line of the centers of the crank pins 21 and the pins 40 and substantially through the mid points of the lines of the said centers. That is, the said centers of the

pins

21, 40, and 42 are located at the vertices of an isosceles triangle, and the pins 4| and 42 are located on opposite sides of the lines of the centers of the crank pins 21 and the pins 48, and the pins 4| and 42 are substantially equally spaced from the said lines.

The connectors are connected to the oscillatable elements 44 by the pins 48. The oscillatable elements 44 are provided with stub shafts 45 that are supported in bearings 38 located just beneath the bearings 28 of the machine drive shafts and at the ends of the sides of the crown. Each of the oscillatable elements 44 is formed'to have bifurcated portions located on opposite sides of the connectors 28 and thus the element enables relative swinging movement of its associated connector 28 between the said portions. (Figs. 6 and 1.)

The oscillatable elements 44 are connected by means of the pins 43 with the links 46, which are in turn connected by the pins 41 with the toggle levers 48, and the toggle levers are rotatably supported on the fixed shafts 48. Each lever 48 is provided with a pair of arms 50, and the arms are connected by means of the pins 5i to the links 52 that are pivotally connected to the plunger 3|.

The distance between the centers of the shafts 45 and the pins 40 is substantially twice the distance between the centers of the main drive shafts I4 and I5 and the centers of the crank pins 21, the shafts 45 being located on the side of the major axes of the connectors opposite that on which the pins 4| are located and substantially in the vertical line of the centers of the machine drive shafts. The pins 41 are located on arms of the lever 48, which are slightly inclined to the central lines of the arms 58. When the connectors 28 are located in their uppermost extreme positions, (Fig. 2) the pins 43 approximate the lines of centers of the shafts 45 and the pins 41 and, at the same time, the arms 50 and the links 52 approximate the center lines of the shafts 49 and the pins 53, and the plunger 3| is located at the extreme point of itsworking stroke.

The connectors 28 are connected to the links 56 by means of the pins 4 l. The links are connected to the levers 58 by the pins 51. The levers 58 are keyed to the shafts 59 that are rotatably supported in the sides of the crown. Each shaft 58 is also provided with the lever arms 60 located at its ends and on the outside of the crown. The arms 50 are connected by means of the pins iii to the toggle links 52, and the toggle links are :gnnected to the plunger 30 by means of the pins When the plungers are located at the extreme of their working strokes, as illustrated in Fig. 2. the centers of the pins 40 and M are located slightly above the lines of the centers of the shafts 45 and the pins 51, and the centers of the toggle levers 60 and the links 62 are located substantially in alignment. The arrangement of the centers of the pins 40, 4|, and 51 with reference to the centers of the shafts 45 operates to produce by the movement of the connectors 28 a more extended dwell in the plunger 30 than in the plunger 3|.

The connectors 28 are connected to the links bythepins 4s. (ra es, s, marl] The links v poi-ted uponhthe shafts," and are connected }by means or thepins 88 tothe links 88. The shafts 81 are supported in bearings 88 located inside parts of and at the ends of the base 22. The links 88 are connected to the toggle levers 18 by means oi the pins H. Each toggle lever 18 is provided with a pair of arms 12 to which are connected the links I8 by means of the pins 14. The links 18 are connected to the lower plunger 82 by means of the pins 18. Thelevers 18 are rotatably supported on the fixed shafts I8 supported in the sides of the base 22. When the links 84 descend by the operation of the connectors 28 and substantially at the completion of the plungers nonworking strokes, the centers of the pins 88 are carried through the lines of the centers of the shafts 81 and the pins 'II to produce an extended dwell and to thus greatly shorten the non-working stroke of the lower plunger 22, thereby enabling considerable reduction in the height of the press.

Thus each of the plungers is connected substantially at each of its four corners by a link, and the links at each end of each plunger are connected to a toggle lever near the ends of its supporting shaft. The toggle levers are connected to the connectors by oscillatable elements, and the connectors connected to the crank pins of the machine drive shafts.

The upper sheet metal shaping plunger 3i completes its

non-working stroke

15 or 20, as measured in the rotation of the machine drive shaft, subsequent to the completion of the non-working stroke of the blank-holding plunger. When the connectors are in the position shown in Fig. 1. they have substantially completed the non-working strokes of the plungers. The centers of the crank pins 21 are located at points between, and in line with, the lines of the centers of the machine drive shafts and I5 and the pins 48. Movement of the crank pins operates to markedly tilt the connectors 28 to more than 20. The tilting is produced by the continued movement of the crank pins 21 across the lines of the centers of the machine drive shafts and the pins 48 connected to the oscillatable elements 44. Tilting of the connectors causes a quick rise of the pins 4!, which initiates the downward stroke of the blank holding plunger 88'.-

The tilting movement also raises the pins 43 and starts the downward movement of the plunger 3| through the connection of the pins 43 and continues the downward movement of the plunger 38. As the crank pins continue to rotate and to rise, the angle of the tilt, increased by the outward movement of the crank pins with respect to the pins 48, moves the centers of the pins 48 and 4| rapidly upward to complete the stroke of the plunger 88. The center lines between the shafts 45 and the pins 43 are also swung rapidly upward, which causes the plunger 3| shortly thereafter to engage the metal. The tilting then substantially ceases, and the connectors are carried bodily upward while maintaining the angle of the tilt and moving the plunger 2| downward at a progressively reducing speed to complete its stroke. The crank pins move upward and then toward the lines of the centers of the machine drive shafts l4 and I8 and the shafts 45, whereupon the connectors markedly reverse the tilting or oscillatory movement to the position shown in Fig. 2. As the connectors are bodily raised, the plunger 82 is act 1.00

a used-en ts di m a he' me J u se en t9 the m ti n: t str v o the plunger as ,the centers of the crank pins 21; a resc t e l n of t e, t r the echine'drive shafts and the pins 48.

The connectors are further tilted as the die 84 of the plunger 8! engages the metal and are moved laterally inward with respect tothe central vertical plane of the press. duringv which time the pins 42 are carried laterally, which pro duces a short dwell during the engagement of the die of the plunger 22. This reverse tilting and lateral body movement of the connectors 28 locates the connectors in position to be moved bodily downward substantially in the direction in which the lines of the centers of the crank pins 21 and the pins 48 extend and to produce the non-working strokes of the plungers.

While the connectors 28 are thus moved diagonally downwardwith respect to the vertical, their major axes are maintained substantially parallel to the direction of their diagonal movements by the movements of the centers of the

pins

21 and 48 outward to produce substantially equal versed sines of one-half the arcs described by the pins. Approximately at the completion of,

the substantially straight line and in the downward movement of the connectors in the direction of their major axes, the crank pins 21 are disposed near the lines of the centers of the machine drive shafts and the pins 48, and a continued movement of the crank pins 21 tilts the connectors 28 about the centers of the pins 48, operating to start the plunger 38 downward in advance of the downward movement of the plunger 3i Further movement of the crank pins 21 increasingly tilts the connectors 28 without material movement of the oscillatable elements 44, thereby causing continued upward movement of the pin 4| and downward movement of the blank holding plunger 88 and starting the downward movement of the plunger 8|. Continued movement of the crank pins 21 then causes the sheet metal holding plunger 38 to engage the metal. Further movement disposes the line of the centers of the

pins

21 and 48 in a marked inclined relation with respect to the vertical. Further rotation of the crank pins 21 causes the oscillatable elements 44 to move angularly about the center of the shafts 45 at an increased rate, which produces a rise of the center of the pin 48 substantially equal to the rise of the crank pins 21 and causes the pins 43 to produce a rapid downward stroke 'of the upper sheet metal plunger 3i to the metal. Upon further rotation of the crank shafts, the line of the centers of the crank pins 21 and 48 are maintained in substantially the same angular position with reference to the vertical, as the connectors are raised bodily, causing the die 84 of the plunger 3| to operate on the metal and to raise the pins 4! and at the same time to move the pins 48 towards the lines of the centers of the shafts 45 and the pins 51 and thus compensate for the change in the length of the lines from the centers of the shafts 48 to the pins 81 and maintain the pins 81 in their positions. The connectors cause the pins 4| to move in a substantially curved line convex to the centers of the shafts 48 and cause the blank holding plunger 38 to hold the metal while it is being operated upon by the vsheet metal plunger 8|. Further upward movement of the crank pins continues to carry the connectors 28 bodily upward, still maintaining the line of the centers of the crank pins 21 and 40 at substantially a constant angle with the vertical. Rotation of the crank pins 21 causes further lifting of thepins 4|, and the pins 40 approach the lines of centers of the shafts 45 and the pins 51 and continue to move the centers of the pins 4| curvedly about the pins 51. The connectors also cause the lower plunger 32 to complete its stroke. Continued upward movement causes the centers of the pins 43 to move toward the line of the centers of the shafts 45 and the pins 41 and maintains'the upper sheet metal plunger 3| in the position of its dwell. The connectors continue to rise to locate the pins 4| above the lines of the centers of the shafts 45 and the pins 51, the pins 40 being still located below the said lines. Upon further movement of the crank pins 21, the. lower plunger 32 engages the work, and the connectors 28 begin to tilt in the reverse direction, moving the pins 40 upward as the pins 4| are swung downward and again compensating for the movement of the pins 4| as the links 56 swing about the pins 51 as centers.

The pins 4| are the first to cross the lines of the centers of the shafts 45 and the pins 51 as the pins 4| move upward. Then the pins 40 cross the lines of the centers of .the shafts 45 and the pins 51 until the pins 4| reach their limit of upward movement, whereupon the pins 4| reverse their circular movement. As the pins 40 move on upward, the pins 4| descend until the said pins 40 and 4| are on opposite sides of the said center lines of the shafts 45 and the pins 51, the pins 51 meantime being held stationary.

The pins 40 and 4| then descend, and the con-- nectors are moved laterally to maintain the dwell of the plunger 30 and produce the dwell of the plunger 32 until the pins cross the lines of the centers of the shafts and the pins 51, and shortly thereafter theplungers begin to leave the work. The connectors are then carried bodily downward substantially in the lines of the centers of the crank pins 21 and the pins 40. The.

operations described above are thus cyclically continued during the rotations of the machine drive shafts.

' The movements of parts of the connectors and the plungers are diagrammatically indicated in Figs. 9 and 10 of the drawings. The zero and the 360 points of rotation of the machine drive shafts are the points at which the centers of the crank pins 21 are in the lines of the centersof the main drive shafts l4 and I5 and the pins 40 and between the' said centers as shown in Fig. 1. Referring to Fig. 9, the center of each pin 4| describes the curvilinear line 11 that produces a substantial reciprocatory movement of the pin 4| and a circular movement about the center of the pin 51 as the point 4| moves in the general direction of the arrows shown in the figure. Substantially at the 75 point of the curvilinear line 11, the point 4| begins to move circularly about the point 51 and reverses at about 105, returning circularly to about the 235 point in the rotation of the shaft. I During this part movement the link 56 oscillates about the pin 51 to retain the blank holding plunger 30 in position to hold the metal while the other plungers perform their functions of drawing and redrawing the metal. The links 56 then operate to draw the levers 58 and move the centers of the pins 6| through the centers of the shafts 59 and the pins 63, and upon continued movement of the pins 4| the plunger is lifted from the work.

The centers of the pins 43 that connect the connectors to the plunger-operating means that operates the plunger 3| describe an are about the centers of the shafts 45. The centers of the pins 42 that connect the connectors to the plunger-operating means that operate the plunger 32 describe a figure 8 loop, .the upper part of the loop being much broader than the lower part of the loop and the top extending with a. small curvature in a general lateral direction.

The relation of the movements of the plungers produced by each plunger operating means as controlled by the connectors 23 is illustrated diagrammatically in Fig. 10. The curves indicate the relative positions of the upper plungers in their strokesas measured from the upper horizontal line and the relative positions of the lower plunger as measured from the lower horizontal line as the machine drive shafts rotate. The diagram presents the timed relation of the parts of the strokes of the plungers and also indicates the dwell periods of the plungers.

The blank holding plunger 30 initiates a descent at about 10 before the 0 point and completes its descent substantially at- 75. It continues to dwell until slightly over 240 and rises to reach its extreme upward movement at about 350. The upper sheet metal shaping plunger 3| begins its descent at slightly less than 10", reduces its rate of movement at about 90, and completes its stroke at about 125. It then dwells from about 125 to slightly over 230 and rises much more rapidly than the blank holder plunger 30. The plunger 32 begins to ascend at about 75 and as it strikes the metal produces a relatively slow upward movement and a dwell from about 215 to about 235. It then recedes gradually from the metal at about the same time or shortly after the upper sheet metal shaping plunger 3| recedes and slightly before the blank holder plunger 30 recedes. After its initial withdrawal the upper sheet metal shaping plunger moves rapidly compared to the rate of movement of the blank holding plunger and loosens the shaped metal from the lower die or bed of the press and enables its removal.

The movement of the connector is related to the movement of the plungers of the press and may be stated in terms of the degree of rotation of the machine drive shaft as follows: from 0 to 75 the connector moves in a rotatory manner in one direction during which the blank holding plunger 30 descends toward the bed of the press; the upper forming plunger. 3| descends toward the bed of the press and the lower forming plunger 32 dwells; from 15 to 105 the connector is moved in a translatory manner in an upward direction with reference to the bed during which the blank holding plunger 30 dwells, the upper forming plunger 3| approaches its full descent with reference to the bed and the lower forming plunger 32 begins its ascent with reference to the bed and toward the plungers 30 and 3|; from 105 to 235 the connector is moved in a rotatory man- 'ner in a direction opposite to the direction of the 350 the connector is moved in a translatory manner in a direction opposite to the previous mentioned translatory movement or in a downward direction with reference to the bed of the press during which the blank holding plunger 33 moves upwardly away from the bed, the upper forming plunger moves upwardly away from the bed of the press andthe lower forming plunger 32 begins its descent and movement away from the bed of the press; and from 350 to 360 the connector is moved in a rotatory manner in the same direction as the first mentioned rotatory movement during'which the blank holding plunger 30 continues its upward movement, the upper forming plunger 3| likewise continues its upward movement and the lower forming plunger 32 dwells.

When the circular part of the curvilinear line FIT, which describes the movement 01 the center of the pin 4| that is connected to the operating means that operates the blank holding plunger 30, is plotted with reference to the degree movement of the shaft and the extent of movement of the center of the pin 51 as measured in the units used in making the other curves of the figure and in the direction that the line of the center of the link 56 takes as the pin 51 is rotated during the dwell period of the plunger 30-that is, between and 235 of rotation of the shaft,

- it produces the curve 18. The difierence between the curves of the blank holding plunger and the curve 18 is produced by the coaction of the toggle levers and the connecting links forming a part of the plunger operating means that operates the blank holder plunger 30. Also, the movement of the center of the pin 42, to which is connected the means for operating the lower plunger 32, is plotted with reference to the extent of vertical movement of the pin 66 as taken along the axis of the link 64 as it is moved from point to point during the lateral movement of the connector, and in the unit used to measure the vertical movement of the plungers the curvilinear line 19 is produced. The diiferences in the curvature of the parts of the curve indicating the movement 01' the lower plunger with reference to the metal and the curved line I9 are produced by the toggle connection formed by the lever 10 and the link 12 that connect the lever H with the lower plunger.

The connectors 28 are reciprocated, tilted, and moved laterally to cause the difierent parts connected to the plunger-operating means to produce sequential plunger engagement and to cause gradual decrease in movement of the plungers during their engagement with the metal to aflord opportunity or time for the metal to adjust itself as it is drawn by the plungers-that is, to enable the metal to flow as it is shaped, to produce dwells of decreasing length in the movements of the plungers that sequentially engage the metal, and to withdraw the plungers substantially simultaneously and produce a rate of withdrawal movement as to cause the work to be released from the dies.

We claim:

1. In a sheet metal press, a connector, a machine drive shaft connected eccentrically to the connector, an oscillatable element pivotally connected to the connector for reciprocating the connector during a part of the rotation of the shaft.

catory movement of the connector and moved laterally during the said lateral movement oi! the connector for producing substantial dwells in the said other plunger.

2. In a sheet metal press, a connector, a machine drive shaft connected eccentrically to the connector for reciprocating the connector, means for guiding the said connector to produce a movement in one part of the connector in one direction and a movement in another part of the connector in another direction at substantially the same time, a. pair of plungers, means for operating the plungers including links pivotally connected to the said parts for producing sequential sheet metal plunger engagement.

3. In a sheet metal press, a connector, means for reciprocating and oscillating the connector, a plurality of plungers, means connected to and actuated by the connector for operating each plunger, each of said last named means independently connected to the connector at points spaced from the points of connection of the other of said last named means with the connector and operating to produce sequential corresponding movements of the plungers.

4. In a sheet metal press, a connector, means for reciprocating the connector and oscillating the connector to diiferent definite positions with reference to the reciprocatory movements of the connector, a plurality of plungers, means connected to and actuated by the connector for operating each plunger, each of said last named means independently connected to the connector at points spaced from the points of the connection of the other of said last named means with the connector, the said first named means operative to maintain the connector substantially in the said definite positions during parts of the reciprocatory movements of the connector for producing recurrent changes in the movements of each of the plungers.

5. In a sheet metal press, a connector, a machine drive shaft connected eccentrically to the connector, an oscillatable element connected to the connector for producing alternate reciprocatory and tilting movements of the connector and a lateral movement of the connector, a pair of plungers, two independent means for connecting each plunger to the connector to produce relative plunger movement according to the movement of parts of the connector to which the said means are connected.

6. In a sheet metal press, a connector, a machine drive shaft connected eccentrically to one end part of the connector for reciprocating the connector, a supporting part, a guiding element pivotally connected to the supporting part and to the other end part of the connector, a lever, a link pivotally connected to the connector at a point spaced from the point of connection of the element with the connector and to the lever, the said pivotal connections being such that when the connector is located near one extreme point in its reciprocatory movements the said pivotal connections with the connector are located above the line between the centers of the pivotal connections of the guiding elements with the supporting part and the pivotal connection of the link with the lever, and upon continued rotation of the shaft, the point of connection of the link with the connector is moved generally in the direction in which the link extends to compensate for the reciprocal movement of the pivotal connection of the link with the connector, a sheet metal engaging plunger and means interconnecting the lever and plunger for reciprocating the plunger.

7. Ina sheet metal press, a connector, a machine drive shaft connected eccentrically to the connector for reciprocating the connector, means for oscillating the connector as it is reciprocated, a pair of reciprocable sheet metal engaging plungers, means for independently connecting each of the plungers to the connector for sequentially actuating the plungers.

8. In a sheet metal press, a connector, a machine drive shaft connected eccentrically to the connector for reciprocating the connector, a pair of plungers, a plunger-operating means for each of the said plungers, a link pivotally connected to the said means and the connector, means for laterally moving the connector to compensate a part of the reciprocatory movement of the connector to arcuately move one link about the point of connection of the said link with its associated plunger-operating means and to move the other link substantially at right angles to the direction in which the said other link extends by the lateral movement of the connector for maintaining the points of connections of the links with each of the said plunger-operating means substantially stationary during a part of the rotation of the machine drive shaft and for reciprocating the plungers during other parts of the rotation of the machine drive shaft.

9. In a sheet metal press, a connector, a machine drive shaft connected eccentrically to the connector for reciprocating the connector, means for tilting the connector during part of the reciprocatory movements, a pair of reciprocable sheet metal engaging plungers, means for connecting each of the plungers to the connector at points located on opposite sides of the line of the general direction of the reciprocatory movements of the connector for producing sequential corresponding parts 01' movements of the plungers.

10. In a sheet metal press'having a fixed part, a connector, a machine drive shaft connected eccentrically to the connector for reciprocating the connector, a pair of sheet metal engaging plungers, a pair of oscillatable elements pivotally connected to the connector at spaced points, a pair of plunger-operating means, each means connected to an element and to a plunger, one of the oscillatable elements connected to the fixed part and operable to tilt the connector to produce sequential plunger engagement.

11. In a sheet metal press, a connector, a machine drive shaft connected eccentrically to the connector for reciprocating the connector, a pair of sheet metal engaging plungers movable in opposite directions to produce sheet metal engagement, an independent plunger-operating means connected to each plunger and including a link, the said links pivotally connected to the connector at spaced points, means for tilting the connector for actuating the said plunger-operating means.

12. In a, sheet metal press, a connector, a machine drive shaft connected eccentrically to the connector for reciprocating the connector, a support, a guide element pivotally connected to the support and to the connector to produce reciprocatory movement of one part of the connector and a movement of another part of the connector substantially lateral to the general direction of the reciprocatory movement and.during the said reciprocatory movement, a plunger, a plungeroperating means connected to the plunger and having a link connected to the said one part of the connector substantially at right angles to the said general direction of the said reciprocatory movement during a part of the said reciprocatory movement, a second plunger, a plunger-operating means connected to the second plunger and having a link connected to said other part of the connector and extending substantially at right angles to the direction of the lateral movement of the connector and operative to reciprocate the plunger and produce a substantial dwell in the plunger during the said lateral movement.

13. In a sheet metal press, a connector, a machine drive shaft connected eccentrically to the connector for reciprocating the connector, a guiding means for guiding the connector in its reciprocatory movements, a pair of links pivotally connected to the connector at spaced points,

a pair of plungers, a plunger-operating means connected to each link and to a plunger, the lines of the points of connection of the links with the plunger-operating means and the connector inclined relative to each other to produce sequential corresponding parts of the movements otQhe plungers.

14. In a sheet metal press, a connector, a machine drive shaft connected eccentrically to one end part of the connector for reciprocating the connector, a supporting part, a guiding element pivotally connected to the supporting part and to the other'end part of the connector, a pair of reciprocable sheet metal engaging plungers, means for connecting each of the plungers with the connector at points on opposite sides of the center line of the pivot points of-connection of the connector with the drive shaft and the guiding element for reciprocating the plungers.

15. In a sheet metal press, a connector, a ma- I chine drive shaft connected eccentrically to the connector for reciprocating the connector, an 05- cillatable element pivotally connected to the connector for oscillating the connector as it is reciprocated, a pair of reciprocable sheet metal engaging plungers, a pair of links, one of the links pivotally connected to the connector, and the other of the links pivotally connected to the oscillatable element, and means for connecting each of the links to a plunger for reciprocating the plungers.

16. In a sheet metal press, a connector, a machine drive shaft connected eccentrically to the connector for reciprocating the connector, means for tilting the connector as it is reciprocated, a pair of links pivotally connected to the connector ducing sequential sheet metal plunger engageplungers, a plunger-operating means connected to each plunger and to each link to locate the lines of the centers of the connections of the links in inclined relation to each other for pro ducing sequential sheet metal plunger engagement.

1'7. In a sheet metal press, a connector, a machine drive shaft connected eccentrically to one end part of the connector for reciprocating the connector, means for guiding the connector, a. pair of links connected to the connector at spaced points, a pair of reciprocable sheet metal engaging plungers, a plunger-operating means connected to each plunger and to each link and operative to dispose the links at different angles relative to the general direction of the reciprocatory movements of the connector to produce sequential sheet metal plunger engagement.

18. In a sheet metal press, a frame, a pair of parallel machine drive shafts located near the top and opposite ends of the frame, a pair of connectors, each machine drive shaft eccentrically Connected to a connector, 9. bed, a pair of sheet metal engaging plungers located at one side of the bed and movable in the same direc-- tion to produce sheet metal engagement, a third plunger located below the bed and movable in a direction opposite to that moved by the other plungers to produce sheet metal engagement, three oscillatable elements pivotally connected to each connector at spaced points, a plunger-operating means connected to each end part of each plunger and to an oscillatable element for operating the plungers, the connecting lines between the points of connection of the oscillatable elements with the connectors and their associated plunger-operating means extending in different directions to produce sequential plunger movements.

19. In a sheet metal press, a connector, a machine drive shaft connected eccentrically to the connector for reciprocating the connector, a plurality of sheet metal engaging plungers, a plurality of oscillatable elements pivotally connected to the connector at spaced points. and located in a line extending transversely to the general direction of the reciprocation of the connector, a plurality of plunger operating means, each means connected to an element and to a plunger, means for tilting the connector to produce sequential plunger engagement.

20. In a sheet metal press, a connector, means for guiding the movement of one point of the connector, a machine drive shaft connected ec centrically to the connector for reciprocating the connector during parts of the rotation of the shaft and for tilting the connector during other parts of the rotation of the shaft relative to said guided point, a plurality of sheet-metal engaging plungers, a plunger operating means connected to each plunger, an oscillatable element pivotally connected to each plunger operating means, the oscillatable elements connected to the connector at spaced points, certain of the said points of connection of the oscillatable elements with the connector located in the line extending transversely to the general direction of the reciprocation of the connector to produce sequential plunger engagement.

21. In a sheet metal press, a connector, a machine drive shaft connected eccentrically to the connector for reciprocating the connector, a plurality of sheet metal engaging plungers, a plurality of oscillatable elements pivotally connected to the connector at spaced points, one element connected to the connector at a point located substantially in the line extending through the center of connection of the shaft with the connector and in the general direction of the reciprocation of the connector, and the other element connected to the connector at a point spaced from the line, a plurality of plunger operating means, each means operatively connected to an oscillatable element and to a plunger, means for tilting the connector to produce sequential plunger engagement.

22. In a sheet metal press, a connector, a machine drive shaft connected eccentrically to the connector for reciprocating the connector, a plurality of sheet metal engaging plungers, a plurality of oscillatable elements pivotally connected to the connector at spaced points, one element connected to the connector at a point located substantially in the line extending through the center of connection of the shaft with the connector and in the general direction of reciprocation of the connector, and the other elements connected to the connector at points located on opposite sides of the line and spaced from the said line, a plurality of plunger operating means, each means operatively connected to an oscillatable element and to a plunger to produce sequential plunger engagement.

23. In a sheet metal press, a connector, means for reciprocating the connector, a pair of sheet metal engaging plungers, means for operating each of the plungers, an oscillatable element connected to each of the said means and to the connector at spaced points, one of the oscillatable elements operative to oscillate the connector as it is reciprocated, means for defining the oscillatory movement of the said one oscillatable element for producing sequential plunger engagement.

24. In a sheet metal press, a machine drive shaft, a connector, eccentrically connected to the machine drive shaft for reciprocating the connector during a part of the rotation of the shaft, means for guiding the connector to cause the connector to oscillate during another part of the rotation of the shaft, a pair of reciprocable sheet metal engaging plungers, means for connecting each of the plungers to the connector for actuating one of the plungers during a reciprocatory movement of the connector and for actuating the other of the plungers during an oscillatory movement ofthe connector.

25. In a sheet metal press, a machine drive shaft, a connector connected eccentrically to the machine drive shaft, a pair of sheet metal engaging plungers, means connected to the connector for reciprocating one of the plungers, an element engaging the connector for guiding the movement of the connector during rotation of the shaft to produce periodic reciprocatory movement and dwell of said one plunger, the said element moved by the connector, and a means connected to said element for reciprocating the other plunger to produce periodic reciprocatory movement of said other plunger in timed relation to the movement and dwell of the said one plunger.

26. In a sheet metal press, a machine drive shaft, a connector connected eccentrically to the machine drive shaft,\a pair of sheet metal engaging plungers movable in the same direction, means connected to the connector for reciprocating one of the plungers, an element engaging the connector for guiding the movement of the connector during rotation of the shaft to produce periodic reciprocatory movement and dwell of said one plunger, the said element moved by the connector, and a means connected to said element for reciprocating the other plunger to produce periodic reciprocating movement and dwell of said other plunger in timed relation to the movement and dwell of the said one plunger.

27. In a sheet metal press, a machine drive shaft, a connector connected eccentrically to the machine drive shaft, means engaging the connector for guiding the movement of the connector during the rotation of the shaft to produce during each rotation of the shaft successive periods of a rotatory movement and a translatory movement of the connector, a pair of sheet metal engaging plungers, a plunger operating means connecting said connector to each of said plung ers, the connections between the connector and said plunger operating means being located at spaced points whereby during one of said periods of rotatory movement one of said plungers is caused to move and the other of said plungers is held substantially stationary and during one of said periods of translator-y movement of the connector said other plunger is moved and said one plunger is held substantially stationary. I

28. In a sheet metal press, a machine drive shaft, a connector connected eccentrically to the machine drive shaft, means engaging the connector for guiding the movement of the connector during the-rotation of the shaft to produce during each rotation of the shaft successive periods of a rotatory movement and a translatory movement of the connector, a pair of sheet metal en-- gaging plungers, a plunger operating means connecting said connector to each of said plungers, the connections between the connector and said plunger operating means being located at spaced points whereby during one of said periods of rotatory movement of the connector both of said plungers are held substantially stationary and during one of said periods of 'translatory movement of the connector both of said plungers are caused to move.

29. In a sheet metal press, a machine drive shaft, a connector connected eccentrically to the machine drive shaft, means engaging the connector for guiding the movement of the connector during the rotation of the shaft to produce during each rotation of the shaft successive periods of a translatory movement and a rotatory movement of the connector, a pair of plungers, a plunger operating means connecting the said connector to each of said plungers, the connections between the connector and said plunger operating means being located at spaced points whereby during one of the said periods of translatory movement of the connector both plungers are caused to move and during one of the said periods of rotatory movement of. the connector one of said plungers is held substantially stationary and the other of said plungers continues to move.

30. In a sheet metal press, a machine drive shaft, a. connector connected eccentrically to the machine drive shaft, means engaging the connector for guiding the movement of the connector during the rotation of the shaft to produce during each rotation of the shaft successive periods of a translatory movement and a rotatory movement of the connector, a pair of plungers, a plunger operating means connecting the said connector to each of said plungers, the connections between the connector and said plunger operating means being located at spaced points whereby during one of said periods of translatory movement of the connector one of said plungers is caused to move and the other of said plungers is held substantially stationary and during one of said periods of the said rotatory movement both of said plungers are maintained substantially stationary.

31. In a sheet metal press, a machine drive shaft, a connector connected eccentrically to said machine drive shaft, means engaging a part of the connector for guiding the movement of the connector during the rotation of the shaft to produce during each rotation of the shaft alternate periods of translatory and succeeding rotatory movements of the connector, a reciprocable sheet metal engaging plunger, a plunger operating means, an element connected to another part of the connector spaced from said first named part and to the plunger operating means whereby the point of connection of the element with the connector moves arcuately about the point of connection of the element with the plunger operating means to cause the said plunger to dwell during one of said periods of translatory and succeeding rotatory movement of the connector and to reciprocate during another and following period of translatory and succeeding rotatory movements of the connector.

32. In a sheet metal press, a machine drive shaft, a connector connected eccentrically to said machine drive shaft, means engaging a part of the connector for guiding the movement of the connector during the rotatioh of the shaft to produce during each rotation of the shaft periods of translatory movement of the connector, a reciprocable sheet metal engaging plunger, a plunger operating means, an element connected to another part of the connector spaced from said first named part and to the plunger operating means whereby the point of connection of the said element with said connector moves arcuate- 1y about the point of connection of the element with the plunger operating means to cause the said plunger to dwell during one of said periods of translatory movement of the connector and to move during another of said periods of translatory movement of the connector.

33. In a sheet metal press, a machine drive shaft, a connector connected eccentrically to said machine drive shaft, means engaging a part of the connector for guiding the movement of the connector during the rotation of the shaft to produce during each rotation of the shaft periods of rotatory movement of the connector, a reciprocable sheet metal engaging plunger, a plunger operating means, an element connected to another part of the connector spaced from said first named part and to the plunger operating means whereby the point of connection of the said element with said connector moves arcuately about the point of connection of the element with the plunger operating means to cause the said plunger to dwell during one of said periods of rotatory movement of the connector and to move during another of said periods of rotatory movement of the connector.

34. In a sheet metal press, a machine drive shaft, a connector connected eccentrically to said machine drive shaft, means engaging a part of the connector for guiding the movement of the connector during rotation of the shaft to produce during each rotation of the shaft periods of rotatory and translatory movements of the connector, a reciprocable sheet metal engaging plunger, a plunger operating means, an element connected to another part of the connectorspaced from said first named part and to the plunger operating means whereby the point of connection of the element with the connector moves arouately about the point of connection of the element with the plunger operating means during one of said periods of rotatory movement of the connector to cause the plunger to dwell and during one of said periods of translatory movement to cause the plunger to move.

35. In a sheet metal press, a machine drive shaft, a connector connected eccentrically to said machine drive shaft, means engaging a part of the connector for guiding the movement of the connector during rotation of the shaft to produce during each rotation of the shaft periods of rotatory and transiatory movements of the connector, a reciprocable sheet metal engaging plunger, 2. plunger operating means, an element connected to another part of the connector spaced from said first named part and to the plungeroperatlng means whereby the point of connection of the element with the connector moves arcuately about the point of connection of the-element with the plunger operating means during one of the said periods of translatory movement to cause the plunger to dwell and during one of the said periods of rotatory movement to cause the plunger to move.

36. In a sheet metal press, a machine drive shaft, a connector connected eccentrically to said machine drive shaft, means engaging a part of the connector for guiding the movement of the connector during rotation of the shaft to produce during each rotation of the shaft periods of rotatory and translatory movements of the connector, a reciprocable sheet metal engaging vplunger, a plunger operating means, an element connected to another part of the connector spaced from said first named part and to the plunger operating means whereby the point of connection of said element with the connector moves arcurately about the point of connection of the element with the plunger operating means during a part of one of said periods of rotatory movement of the connector to cause the plunger to dwell and during a part of one of said periods of translatory movement to cause the plunger to move.

37. In a sheet metal press, a machine drive shaft, a connector connected eccentrically to said machine drive shaft, means engaging a part of the connector for guiding the movement of the connector during rotation of the shaft to produce during each rotation of the shaft periods of translatory and rotatory movements of the connector, a reciprocable sheet metal engaging