US2827870A - High speed metal drawing press - Google Patents

Description

March 25, 1958 Filed May 21. 1952 '7' Sheets-Sheet 1 FIG. I

INIVENTOR: EINAR K. JOHANSEN March .25, 195

E. K. JOHANSEN HIGH SPEED METAL DRAWING PRESS 7 Sheets-Sheet 3 Filed May 21. 1952 IINVENTOR. EINAR K. JOHANSEN BY wwpww ATI' vs March 25, 1958 E. K. JOHANSEN HIGH SPEED METALDRAWING PRESS 7 Sheets-Sheet 4 Filed ma 21. 1952 I INVENTOR. EINAR K. JOHANSEN March 25, 1958 E. K. JQHANSEN I 2,827,370

HIGH SPEED METAL DRAWING PRESS Filed May 21, 1952 7 Sheets-Sheet 6 YINVENKTORJ .EINAR K. JOHANSEN March 25, 1958 E. K. JOHANSEN 2,827,870

HIGH SPEED METAL DRAWING PRESS Filed May 21, 1952 7 Shets-Sheet 7 F|G.|O

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' EINAR K. JOHANSE N B United States Patent-"O HIGH SPEED METAL DRAWING PRESS Einar K. Johansen, Oak Park, Ill., assignor, by mesne assignments, to U. S. Industries, Inc., a corporation of Delaware Application May 21, 1952, Serial No. 289,143 6 Claims. (Cl. 113-38) This invention relates in general to presses of the type for forming, shaping, or drawing sheet metal, and, particularly, to mechanically operated presses for performing such functions. More specifically, the invention relates to mechanically operated presses of the so-called double action type.

'Mechanically operated metal drawing presses of the double-action type as presently used employ an outer or blank holder slide which clamps a sheet metal blank or workpiece and an inner slide which forms, draws, or shapes, the sheet metal after it has been clamped in position by the outer clam-ping or blank holder. slide. These present presses have proven very satisfactory in general, but they have the disadvantage in that because of the crank or eccentric mechanical means commonly used to operate them heretofore, they were unable to produce the desired production quantity principally because the number of operating cycles per period of time has been limited.

The inadequacies of the number of operations or operating cycles per period of time retards the production line and, therefore, limits and preventsrapid production. The reasons for the lack of more rapid production because of the limited number of cycles of operation within a given time limit is due to the construction, position, and arrangement of the parts. Such mechanical presses operated by cranks or eccentrics must necessarily operate for the forming or drawing of the sheet metal at a speed consistent with the type of sheet metal currently available. The presently available sheet steel ordinarily has an approximate drawing or flowing speed of about sixty feet per minute. The actual speed of drawing sheet steel is, therefore, limited by the flowing or draw speed of the metal. Should the draw speed of the metal be increased, the sheet metal would fracture, break, or otherwise prevent a proper metal draw.

Conventional mechanical crank operated metal drawing presses, therefore, have had the disadvantage in thatthe throw of the crank determined the deph of the draw or the depth of the draw to 'be performed onthe metal determined the throw of the crank to be used. For example, should a metal draw of twelve inches be required, the vertical movement of the inner .or draw slide must be at least twenty-four inches plus an additional amount to permit the finished drawn metal or-article to be withdrawn from .the dies. The metal draw slide must move twelve inches from the point it first engages theblank to finish the. twelve-inch draw. The draw slide must then be raised twelve inches to withdraw it from the finished piece where it will be at the same: point wherethe metal drawing operation began. It is then necessary to raise the draw slide an additional twelve inches so that the finished or drawn sheetmay-be withdrawnfrom the press. Of course, there must be more .than twenty-four inches over-all travel so that the finished drawn piece may be withdrawn freely from the press. In any event the metal drawing slide must have at least a twenty-four inch travel or movement for a twelve-inch metal draw.

2,827,870 7 Patented Mar. 25, 1958 Fee The crank which operates the draw slide to form a twelve-inch draw must necessarily have at least a twentyfour inch stroke and inasmuch as the crank rotates and the crank connections operate in an arc, the actual peripheral length of the are about which the crank connection travels, or the crank throw, will be diameter times pi (2X 3.1416) or approximately 6.2832 feet per minute. Since the drawing speed of sheet steel as used at the pres ent time is about sixty feet per minute the movement of the crank must be limited in speed according to the maximum permissible draw speed of the metal, i. e., sixty feet per minute. Therefore, to eifect a twelve-inch draw the peripheral rotative speed ofthe crank will be 6.2832 feet per minute. Because the maximum metal drawing speed of the metal is limited to approximately sixty feet per minute, the number of cycles that the press can perform with a crank of this given size is 60 divided by 62832, or approximately 9 /2 (9.54) cycles per minute.

Being limited by the length or the depth of the draw and the safe maximum speed at which metal may be drawn, thecrank must be of a proportional size, and, therefore, it is impossible to increase the production rate of the commonly used crank operated presses.

The present invention has to do with increased production of metal drawn articles without increasing the actual drawing speed of the metal, the metal drawing operation still being limited by the conventional type of sheet steel available which has an approximate drawing speed of sixty feet per minute. The broad conception of the manner in which this increased production may be accomplished involves primarily movement of the draw slide toward the blank at an increased rate of speed during movement of the blank holder slide toward the blank so that when the'blank holder slide reaches its dwell or clamping position, the inner or draw slide will be in a position to immediately begin the drawing operation. Various specific means have heretofore been designed for accomplislb ing this broad purpose in a double-action press such as that shown, for example, in Patent No. 2,550,061 to Glasner and Johansen, the Johansen Patent No. 2,550,063, the Ward Patent No. 2,550,064, and the co-pending application of Johansen, Serial No. 177,981; filed August 7, 1950. The present invention constitutes a still further modified and improved mechanism for thus increasing the production of metal drawn articles.

The primary object of the present invention, therefore, is to maintain the present drawing speed to which sheet steel is limited but to provide a new and improved system of operating mechanism to effect a greater number of cycles of operation of a mechanical press over a given period of time.

Another'object of the invention is the provision of new and improved mechanism for a double-action press whereby the operating mechanisms for the slides are interconnected and correlated to etfect simultaneous travel of both slides to the point of dwell or clamping position of the blank holder slide and then to maintain the blank holder slide in its clamping position while the inner or draw slide is moved independently to effect the draw and then to withdraw both slides from operation and then thereafter to move both slides simultaneously to their but increasing the number of operating cycles per minute over the conventional mechanically operated crank or eccentric driven double-action presses. I

A still further and more specific object of the invention is the provision of new and improved mechanism a for correlating the operation of the draw slide and the blank holder slide in a double-action press so that the draw slide will be in a position readily to begin the drawing operation when the blank holder slide reaches its clampin'g position thereby reducing the usual effective vertical movement of the draw slide operating mechanism by eliminating the ordinary crank throw employed in connection with the conventional crank or eccentric type operated draw slide.

Still another and specific object of the invention is to provide in a mechanical metal drawing press eccentric operating mechanism for the blank holder slide and eccentric operating mechanism for the draw slide wherein the eccentric operating mechanism for the draw slide is eccentric mechanism itself is causedto reciprocate with the reciprocation of the blank holder slide from its initial starting position to its clamping position and return to its original position independently of the movement of the draw slide eccentric for operating the draw slide for a drawing operation.

A still further object of the inventionis to provide a novel mechanism for operating the draw slide in a metal drawing press for a drawing operation wherein the mechanism for operating the blank'holder slide also causes a bodily shifting or reciprocating movement of the driving mechanism for the draw slide.

Other objects and advantages of the invention will become apparent upon reading the following description taken in conjunction with the accompanying drawings in which:

Fig. 1 is an end elevational view of a double-action mechanical metal drawing press embodying the present invention;

Fig. 2 is a vertical longitudinal sectional view taken along the plane of line 22 of Fig. 1;

Fig. 3 is a fragmentary vertical transverse sectional view of a portion of the press taken along the plane of line 3-3 of Fig. 2;

Fig. 4 is a vertical transverse sectional view partly in elevation taken along the plane of line 44 of Fig. 2;

Fig. 5 is a fragmentary horizontal sectional view taken along the plane of line 5-5 of Fig. 4;

Fig. 6 is a vertical longitudinal sectional view partly in elevation taken along the plane of line 66 of Fig. 7;

Fig. 7 is a fragmentary vertical transverse sectional view taken along the plane of line 7-7 of Fig. 6 and showing a portion of the operating mechanismin elevation;

Fig. 8 is a fragmentary plan view along the plane of line 88 of Fig. 6;

Fig. 9 is a horizontal sectional view through a portion of the operating mechanism taken along the plane of line 9-9 of Fig. 2; and

Fig. 10 is a cyclograph or motion curve illustrating the relative movement of the blank holder slide and draw slide of a double-action press utilizing the present invention. 1 r

Referring now more particularly to the drawings which illustrate a preferred embodiment of the present invention, the press is composed of a frame structure generally indicated by the numeral 1 which frame structure may be of the ordinary and usual construction including a bed 2, uprights 3, and a tie member 4 secured between the uprights at the top thereof. a

As illustrated herein, the press is constructed with a bottom drive mechanism commonly known. as an underslung type wherein the operating and driving mechanisms;

for the slides are located below the floor line. It is 4 understood, however, that the present invention can be applied with equal effectiveness to a top drive press wherein .the operating mechanism is positioned in the crown thereof.

As stated hereinabove the press illustrated is a doubleaction press where the outer blank holder slide is moved toward the bed on which there is positioned a die for supporting a blank to be drawn. The inner draw slide is mounted formovement within the blank holder slide and is operated to perform a drawing operation on the blank as it is held in place by the blank holder slide. It may be mentioned here that the primary difference between the double-action press illustrated and a tripleaction press is that in the latter there is provided a second draw slide below the bed which is operated to perform a second drawing operation on the metal blank during the dwell period of the blank holder slide and the upper draw slide. The present invention, therefore, can be applied to a triple-action press with slight modification of the operating means'for the upper draw slide so that it will have a short periodv of dwell before returning upwardly to its original starting position.

The blank holder slide is illustrated herein by the numeral 5 in Figs. 2, 4, and 6. This outer blank holder slide has guideways thereon adapted to cooperate with guideways in t-he frame structure as illustrated by the numeral 6 in Fig. 8 to guide the slide in its reciprocating movement toward and away from the bed.

The inner or draw slide 7 (Figs. 4, 7, and 8) is mounted within the blank holder slide 5 and is similarly guided in its reciprocating movement with respect to the blank holder slide in the usual and well-knownmanner.

The, blank holder slide 5 is provided with a plurality of pull rods 8, two at each side of the press, as more clearly indicated in Fig. 4. Each pull rod at its upper end threadfedly engages a nut or collar 9 above the blank holder slide and may be adjusted to be in contact therewith. A. similar internally threaded collar 9a threade'dly engages each pull rod- 8 at a point spaced downwardly from the upper collar 9 and is adapted to be moved against the underside of a portion of the blank holder slide so that when the pull rods 8 are caused to reciprocate longitudinally, they will carry the blank holder slide with them. The threaded collars 9 and 9a may be adjusted to vary the position of the blank holder slide with respect to the'bed so that allowance may be made for different thicknesses of metal and also to permit the pressure exerted by the blank holder slide to be varied.' i V The pull rods 8 extend downwardly through the frame structure of thep'ress and support at their lower ends a cross head 10. The two pull rods 8 at each side of the press 'engageand' support one cross head 10' so that there will beon'e such cross head at each side of the press, or a t'otalof two. The cross head 10 is illustrated in Figs. 2, 3, 4, 6, 7, and9.

As'rnore clearly illustrated in Fig. 4, the lower end of ea'cn'pun rod 8 has a smaller diameter for a short distanceas indicated at 11 thereby to provide a-shoulder 12 adapted to contact the 'uppersurface of the cross head 10; An internally threaded collar or nut 13 threadedly engages the bottom'end of each pull rod 8 and bears against theunderside of the cross head 10. It will thus far beevident tl'lat when the cross heads 10 are caused to reciprocate vertically, they will impart a similar movemerit tothelpull rods 8 which, in turn, will cause reciprocation of the blank holder slide 5.

The cross heads 10 are operated in their reciprocating movement a drive mechanism which includes a main drive shaft 14. (Figs. 1, 3, 4, and 9). This main drive shaft 14. maybe driven from any suitable source of power (not showhl which may be caused to drive the intermediategear 15 mountedon the shaft 14. The ar rangement of the main drive shaft 14 and its association with the mechanism driven by it is more clearly illustrated in Fig. 9; The mechanism shown in Fig. 9 may be located at the back of the press and there will be two such mechanisms, one at each end of the press. A description of one will, therefore, suffice for both.

A driving pinion 16 is keyed to the main drive shaft 14 and is in mesh with the blank holder slide main gear 17; This gear 17 is keyed to a shaft 18 (Figs.- 1, 2, and 9) mounted in suitable bearing blocks 19. Each shaft 18 at the outer end thereof has keyed thereto an eccentric 20 having an eccentric strap 21 surrounding it. The eccentric strap 21 at each end of the press is provided with a link portion 22 pivotally secured to a cross head 23 mounted for vertical reciprocating movement in guideways 24. Each cross head 23 is also provided with outwardly extending cars 25 at each side thereof and a link 26 is pivotally mounted by means of pivot pins 27 to each of the ears 25.

The outer end of each link 26 is pivotally secured by means of a pivot pin 28 to another link 29, as shown in Figs. 1, 5, and 6. Each link 29 is keyed to a shaft 30 Which extends inwardly of the press, as shown in Fig. 6. The shaft 30 is mounted for rotation in suitable bearing blocks 31 and has keyed to the inner end thereof a sleeve 32 having arms 33 extending radially outwardly therefrom thereby constituting a linkage mechanism. As shown in Figs. 3, 6, and 7, each link 33 is provided with a pair of pivot pins 34 thereby to pivotally connect links 33 to links 35. The opposite end of each link 35 is pivotally connected to the cross head 10 by means of the pivot pin 36 mounted in a suitable bearing arrangement 37 extending between the sides of the cross head 10.

By means of the foregoing mechanism including the main drive shaft 14, pinion 16, blank holder slide main gear 17, eccentric 2t} and the linkage mechanism just described between the cross head 23 and the cross head 10, the blank holder slide is caused to reciprocate. The position of the blank holder slide in the various figures of the drawings is in its lowermost clamping position during the dwell period thereof. As gear 17 continues to rotate causing rotation of the eccentric 20 and upward movement of the cross head 23, the links 26 and 29 will impart a rocking movement to each of the rock shafts 36. This rocking or rotative movement of the shafts 30 will cause links 33 and 35 to be moved upwardly and elevate the cross head 10 to which the blank holder slide 5 is connected by means of the pull rod 8. Continuous oper-' ation of the blank holder slide main gear 17 will return the blank holder slide to its initial upper position from the clamping position thereof shown in the drawing and will thereafter move the blank holder slide toward the bed and back to its dwell clamping position. The link age connection between the cross head 23 and the cross head 10 is such as to cause the blank holder slide to reach its clamping position prior to the lower dead center position of the eccentric 20 and will cause the blank holder slide to move away from the bed a period of time after the eccentric 20 has'passed its lower dead center position thereby causing a dwell in the blank holder slide as more clearly illustrated by the motion curve of the outer blank holder slide illustrated in Fig. 10.

r The invention herein also embodies novel mechanism for moving the inner draw slide both with the blank holder slide and with respect thereto so that by the time the blank holder slide reaches its clamping position, the draw slide will be substantially in the position ready to begin the drawing operation.

Reference will now be made particularly to Figs. 2 and 4 which moreclearly illustrate this novel mechanism foroperating the draw slide. It will be noted in Fig. 4 that each cross head 10 is provided with two of the pivot pins 36, one at each end thereof, and intermediate these pivot pins a shaft 38 is located substantially in the center of each cross head 10 and is mounted for rotation within the cross head in bearing blocks 39 (see also Fig. 9).

Each shaft 38 has mounted thereon between the sides of shoulder 47 thereon adapted to abut the upper surface of the associated cross head 44. Each pull rod extends downwardly through the cross head 44 and has threadedly mounted to the lower end thereof a nut or collar 48 which abuts the lower surface of the cross head 44. Each pull rod 45 also extends upwardly through the frame structure of the press above the cross heads 44 and support at their upper ends the inner draw slide '7. While the connection between the pull rods 45 and the draw slide 7 may take any suitable or desired form, the connection illustrated herein is one which is in common use for the purpose of mechanically adjusting the position of the draw'slide with respect to the bed. The upper end of each pull rod 45 is threaded and engages a worm gear '49 (Figs. 4 and 8) suitably secured to the upper side of the draw slide 7. A worm 50 engages each worm gear 49 and has a shaft 51 connected therewith adapted to be rotated by means of a smallmotor 52. There is an identical arrangement associated with each of the pull rods 45 so that when the motor 52 is operated to rotate the worm 56 a worm gear 49 associated with each of the four pull rods 45 will be rotated to shift the vertical position of the draw slide. Itwill be clear. that rotation of shaft 38 to rotate the eccentric :40 andits link portion 42 will cause a vertical feciprocation of each, of the inner slide cross heads 44 and a similar reciprocation of the draw slide 7 by means of its connection with cross heads 44 through the pull rods 45.

Each shaft 38 in the present embodiment of the invention is caused to rotate by means of a draw slide main gear 53 keyed thereto adjacent the inner end thereof as shown in Figs. 2 and 9. Each gear 53 is driven by engagement with a pinion 54 mounted on the main drive shaft 14. Thus, it will be seen that the main drive shaft 14 through pinion 16 will cause the blank holder slide to reciprocate and will also cause the draw slide to reciprocate to perform a drawing operation by means of the pinion 54 and gear 53. Since, however, the operating mechanism for the draw slide which includes shaft 38, eccentric 40, eccentric strap 41 and link 42, and gear 53, are. all mounted for movement with the blank holder slide, and since the drive means for this operating mechanism is mounted on the frame structure and, therefore, does not move with the blank holder slide, it has been necessary to 'devise some means by which the gear 53 and pinion 54 will aways remain in driving contact with each other. The mechanism for accomplishing this purpose is more clearly shown in Figs. 3, 7, and .9.

In these figures it will be noted that the shaft 38 and the bearing blocks 39 in which it is mounted are both mounted in guideways 55 associated with an opening 56 in each side of the cross head 10. This permits the entire operatingassembly for the draw slide, including shaft 38 and all of the mechanism mounted thereon to shift transversely with respect to the cross head 10. Each end of shaft 38 is provided with a link. One link 57 is located around the outer end of shaft 38 and extends outwardly and around the driveshaft 14. The other link 58 surrounds the hub of gear 53 at the inner end of shaft 58 and extends outwardly and around the main drive shaft 14. Since the pinion 54 for driving gear 53 is mounted on the drive shaft 14, it will have the same center of rotation as the. links 57 and 58. Thus, in order to maintain the pinion 54 and main gear 53 in; constant mesh during the reciprocation ofthe cross head 10, the links 57 and 58 will cooperate to maintain constant the distance between the center of rotation of the pinionand the center of rotation of the gear. For example, viewing Fig. 3, as the cross head 10 moves upwardly to elevate the blank holder slide, the operating mechanism for the draw slide will also move upwardly because the shaft 38 and its connected parts are mounted thereon, As the cross head 10 moves upwardly, however, the links 57 and 58 will cause a shifting ofthe bearing block 39 and shaft 38 toward the right thereby permitting the centers of rotation of the pinion 54 in gear 53 to remain at a constant distance from each other. a

The parts are arranged so that the operating mechanism for the blank holder slide including gear 17, eccentric 20, cross head 23, and the parts associated therewith, will cause the blank holder slide to begin its upward movement after the drawing operationhas been completed. When the cross head 10; and; its connected blank holder slide moves upwardly, it will carry with it the draw slide 7 and its operating mechanism including shaft 38, gear 53, eccentric 40, and link t2 During this upward movement, however, shaft 38 will also berotated to operateeccentric 40 and thereby independently raise the draw slide 7 with respect to the blank holderslide. The draw slide will thus move upwardly at a greater rate of speed than the blank holder slide in accordance with the motion curve thereof illustrated inFig. 10. Fig. also shows, that the blank holder slide will reach its. uppermost or initial position and begin its downward movement toward .the bed while the draw slide is still moving upwardly. As .soon as the draw slide starts to move downwardly by its own independent operating mechanism, it vis also being carried downwardly with the blank holder slide because the operating mechanism for the draw slide is mounted on the cross head 10. The draw slide will, therefore, move downwardly also at a greater rate of speed than the blank holder slide "so that when the blank holder slide reaches its dwell clamping position, the draw slide will be' substantially in a position to begin its drawing operation. At this point the. draw slide is moved'forthe drawing operation independently of the blank holder slide by means of its own operating mechanism. Assoon as the drawing operation. is completed, the draw slide will begin its upward. movement and immediately thereafter the blank holder slide will again move upwardly.

Theprecise relationship between, the movement of the draw slide and the movementof the blank holder slide need not be identical with that shown by the motion curves of Fig- 10. The movement of the draw slide during the movement of the blank holder slide is not important as long as the draw slide is in an approximate position ready to begin the drawing operation when the L blank holder slide begins its dwell.

It is thus clear that for a twelve inch draw the throw of the eccentric which operates the draw slide need not be more than the minimum amount necessary to move the draw slide the twelve inchesfor the drawing operation. Movement of the blank holder slide will carry the draw slide. with it the remaining necessary distance to permit removal of the drawn metal from the press. It is also evident that-with the foregoing arrangement a great'many moreicycles of the press may be completed per minute withoi t increasing the draw. speed thereof than has been heretofore possible with the customary crank or eccentric arrangements. The foregoing construction also has the advantage of eliminating much of the complicated linkage devices which have been used in prior presses for accomplishing the same purpose.

Having the operating mechanism for" the drawslide mounted either on the blankholder slide or on some. part thereof or otherwise mounted in some manner to move with theblank holder slide down to the point of draw permits elimination of many parts heretofore used, particularly, with the novel arrangement herein disclosed which permits the drivev means for the drawslide operating mechanism to be mounted on the frame structure and still permit a direct drive such as by means of the gear and pinion arrangement shown, or otherequiv alent mechanism Changes may be made in the form, construction and arrangement of parts from those disclosed herein without in any way departing from the spirit of the invention or sacrificing any of the attendant advantages thereof, provided, however, that such changes fall within the scope of the claims appended hereto. 7

The invention is hereby claimed as follows:

i. A mechanical metal drawing press comprising a frame structure including a bedfa blank holder slide slidably mounted on the frame structure, a draw slide slidably mounted in the blank holder slide and movable withrespect thereto, blank holder slide operating mechanism for causing the blank holder slide, to move toward the bed to clamping position and then dwell, a cross-head spaced from and mounted for movement with said blank holder slide, draw slide operating mechanism connected with said draw slide and mounted on said cross-head for movement therewith and for a transverse movement with respect thereto, whereby said blank holder slide operating mechanism will cause both of said slides to move toward and away from the bed and said draw slide operating mechanism will cause said draw slide to perform a drawing operation during the dwell of said blank holder slide, both of said slide operating mechanisms being so arranged and coordinated that said draw slide will be sub stantially in position to begin the drawing operation when said blank holder slide reaches the dwell clamping position thereof, drive meansfor both of said mechanisms mounted in fixed position on said frame structure, and means to move said draw slide operating mechanism transversely of said. crosshead, thereby to maintain it in driving engagement withsaid drivemeans during movement of said draw slide operating mechanism toward and away from the bed.

2. A mechanical metal working press comprising a frame structure including a bed, a blank holder slide slidably mounted on the frame structure, a draw slide slidably mounted in the blank holder slide and movable with respect thereto, blank holder slide operating mechanism for causing the blank holder slide to move toward the bed to clamping position and then dwell and thereafter returning the blank holder slide to theinitial positionthereof, support means mounted for movement with said blank holder slide, draw slide operating mechanism including a main gear mounted on said support means for bodily movement with said blank holder slide. and for a transverse movement with respect thereto, whereby. said blank holder slide operating mechanism will cause both of said slides to move toward and away from the bed, both of said slide operating mechanisms being so ar ranged and coordinated that said draw slide will be substantially in position to begin the drawing operation when said blank holder slide reaches the dwell clamping position thereof, drive means for said blank holder slide operating' mechanism mounted on said frame structure, drive means for said draw slide operating mechanism including a pinion mounted on said frame structure in mesh with said main gear, and means for maintaining said gear and pinion in constant mesh during bodily movement of said gear with said blank holder slide.

3. A mechanical metal working press comprising a frame structure including a bed, a blank holder slide slidably mounted on the frame structure,.adraw slide slidably mounted in the blank holder slide and movable with respect thereto, blank holder slide, operating mechanism for causing the blank holder slide to move toward the,

bed to clamping position and then dwell and thereafter returning the blank holder slide to the initial position thereof, support means mounted for movement with said blank holder slide, draw slide operating mechanism including a main gear and an eccentric driven thereby connected with said draw slide and mounted on said support means for bodily movement therewith and for a transverse movement with respect thereto whereby said blank holder slide operating mechanism will cause both of said slides to move toward and away from the bed, both of said slide operating mechanisms being so arranged and coordinated that said draw slide will be substantially in position to begin the drawing operation when said blank holder slide reaches the dwell clamping position thereof, drive means for said blank holder slide operating mechanism mounted on said frame structure, drive means for said draw slide operating mechanism including a pinion mounted on said frame structure in mesh with said main gear, thereby to move said draw slide fora drawing operation during the dwell of said blank holder slide, and means for maintaining said gear and pinion in constant mesh for continuously driving said gear and-eccentric during bodily movement thereof with said blank holder slide.

4. A mechanical metal working press comprising a frame structure including a bed, a blank holder slide slidably mounted on the frame structure, a draw slide slidably mounted in the blank holder slide and movable with respect thereto, blank holder slide operating mechanism for causing the blank holder slide to move toward the bed to clamping position and then dwell and thereafter returning the blank holder slide to the initial position thereof, support means mounted for movement with said blank holder slide, draw slide operating mechanism including a main gear mounted on said support means for movement therewith and with respect thereto, said last named mechanism being operable to cause a drawing operation to be performed by the draw slide during the dwell of the blank holder slide, both of said mechanisms being so arranged and coordinated that said draw slide will be substantially in position to begin the drawing op eration when said blank holder slide reaches the dwell clamping position thereof, drive means for said blank holder slide operating mechanism mounted on said frame structure, drive means for said draw slide operating mechanism including a pinion mounted on said frame structure in mesh with said main gear, means slidably mounting said main gear on said support means, and link means connecting said main gear with the drive means therefor, whereby said gear and pinion will be maintained in constant mesh for continuously driving said main gear during bodily movement thereof with said blank holder slide.

5. A mechanical metal drawing press comprising a frame structure including a bed, a blank holder slide slidably mounted on the frame structure, a draw slide slidably mounted in the blank holder slide and movable with respect thereto, support means mounted on the frame structure for movement with said blank holder slide, blank holder slide operating mechanism for causing the blank holder slide to move toward the bed to clamping position and then dwell, an eccentric connected with said draw slide and operable to move the draw slide with respect to the blank holder slide for performing a drawing operation, gear means associated with said eccentric adapted to be driven to operate said eccentric, said eccentric and gear means being mounted on said support means, whereby reciprocation of said blank holder slide and support means will cause said draw slide to reciprocate therewith, means also mounting said gear means for an additional bodily movement with respect to said support means, drive means for said blank holder slide operating mechanism mounted on said frame, a driving pinion on said frame in driving engagement with said gear means, and means to maintain said gear means and pinion in driving engagement during reciprocation of said gear means with said blank holder slide and support means, said blank holder slide operating mechanism and said eccentric being so coordinated that operation of said drive means for the blank holder slide will move both slides toward the bed, bringing the blank holder slide into clamping position and causing the same to dwell, and that operation of said eccentric will effect further movement of the draw slide during the dwell of the blank holder slide.

6. A mechanical metal drawing press comprising a frame structure including a bed, a blank holder slide slidably mounted on the frame structure, a draw slide slidably mounted in the blank holder slide and movable with respect thereto, blank holder slide operating mechanism for causing the blank holder slide to move toward the bed to clamping position and then dwell, an eccentric connected with said draw slide and operable to move the draw slide with respect to the blank holder slide for performing a drawing operation, support means on the frame mounted for movement with said blank holder slide, a shaft on said support means on which said eccentric is mounted, whereby reciprocation of said blank holder slide and support means will cause said draw slide to reciprocate therewith, means mounting said shaft for sliding movement with respect to said support means, gear means on said shaft adapted to be driven to operate said eccentric, drive means for said blank holder slide operating mechanism mounted on said frame, a pinion for driving said gear means also mounted on said frame, and a link connecting the shaft for said pinion with said shaft for the gear means, whereby said gear means and its shaft will move in an arcuate path during reciprocation of said blank holder slide, thereby to maintain said gear means and pinion in constant driving engagement, said blank holder slide operating mechanism and said eccentric being so coordinated that operation of said drive means for the blank holder slide will move both slides toward the bed, bringing the blank holder slide into clamping position and causing the same to dwell, and that operation of said eccentric will effect further movement of the draw slide during the dwell of the blank holder slide to perform the drawing operation.

References Cited in the file of this patent UNITED STATES PATENTS 1,322,533 Candee Nov. 25, 1919 1,623,960 Byerlein Apr. 12, 1927 1,910,523 Crane May 23, 1933 2,366,172 Bohn Jan. 2, 1945 2,404,181 Klocke July 16, 1946 2,429,062 Joh-ansen 1-. Oct. 14, 1947 2,522,746 Byerlein Sept. 19, 1950 2,550,063 Johansen Apr. 24, 1951 2,550,064 Ward Apr. 24, 1951 2,688,296 Donly et al. Sept. 7, 1954

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