US2550063A - High-speed metal drawing press - Google Patents

Description

April 1951 E. K. JOHANSEN 2,550,063

HIGH-SPEED METAL DRAWING PRESS Filed Aug. 7, 1950 1o Sheets-Sheet 1 IN V EN TOR.

14mm Jaizczwerz,

April 24, 1951 E. K. JOHANSEN HIGH-SPEED METAL DRAWING PRESS 10 Sheets-Sheet 2 Fi ia Aug. 7, 1950 INVENTOR. llrza/fizifa/zaizserz, BY

April 1951 E. K. JOHANSEN 2,550,063

HIGH-SPEED METAL DRAWING PRESS Filed Aug; 7, 1950 10 Sheets-Sheet 3 4 INVENTOR. 5 iuzarJZJo/wzzsem,

April 24, 1951 E. K. JOHANSEN HIGH-SPEED METAL DRAWING PRESS 'INVENTOR. [mar/z. [Jo/242226672,

10 Sheets-Sheet 4 Filed Aug. '7, 1950 April 24, 1951 E. K. JOHANSEN HIGH-SPEED METAL DRAWING PRESS 10 Sheets-Sheeb 5 Filed Aug. 7, 1950 l N V EN TOR. [Z/zar A. t/aizarme/z,

BY W, 7? w April 24, 195] JOHANSEN 2,550,063

HIGH-SPEED METAL DRAWING PRESS Filed Aug. '7, 1950 10 Sheets-Sheet 6 i v INVENTOR. Eliza/f6 do/ zarwafz/ April 24, 195] E. K. JOHANSEN HIGH-SPEED METAL DRAWING PRESS l0 Sheets-Sheet 7 Filed Aug. '7, 1950 4 INVENTOR. Ema/f5. Jolzczrzeew BY 0 10% ma MW April 24, 1951 E. K. JOHANSEN HIGH-SPEED METAL DRAWING PRESS l0 Sheets-Sheet 8 Filed Aug. '7, 1950 INVENTOR. guzzzrlJokarzaem,

April 24, 1951 k, JoHANs -N 2,550,063

HIGH-SPEED METAL DRAWING PRESS Filed Aug. '7, 1950 10 Sheets-Sheet 9 IN V EN TOR.

1127mm Jb/zarwe/z,

April 24, 1951 E. K. JOHANSEN HIGH-SPEED METAL DRAWING PRESS 10 Sheets-Sheet 10 Filed Aug. '7, 1950 QEQQSQQQMQQESSQQRONQ INVENTOR. flizarfflJa/zarzaam BY Patented Apr. 24, 1951 HIGH- SPEED METAL DRAWING PRESS Einar K. Johansen, Oak Park, Ill., assignor to Clearing Machine Corporation, Chicago, 111., a corporation of Illinois Application August '7, 1950, Serial No. 177,982

9 Claims.

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 as distinguished from hydraulically operated presses. More specifically, the invention relates to mechanically operated presses of the so-called double action type of the general character disclosed in the co-pending application of Rudolph W. Glasner and Einar K. Johansen, Serial No. 122,208, filed October 19, 1949. The mechanical double action press of said co-pending application is of the so-called underslung type, wherein the actuating mechanism for the slides is located in the base of the press. The present invention distinguishes in many respects over said co-pending case and, particularly, in that the actuating mechanism for the slides is located in the crown of the press.

Increased production may also be obtained in presses of this general character by the use of specifically different actuating mechanisms for the slides. For example, in my copending application, Ser. No. 177,981, filed August 7, 1950, there is illustrated an actuating mechanism for the inner or draw slide which is mounted on the blank holder slide and reciprocates therewith. A separate actuating mechanism for the blank holder slide is mounted in the crown of the press. In the copending application of William Ward assigned to the present assignee and bearing Serial No. 177,983, filed August 7, 1950, a still further mechanism is disclosed for increasing production wherein a single mechanism for actuating both the blank holder and draw slides is mounted on the blank holder slide and reciprocates therewith. The present invention differs in many respects from all of these other above referred to copending applications in that the actuating mechanism for both slides is mounted in the crown of the press and a novel form of mechanism operates from a single drive to actuate the two slides in a predetermined time sequence, as will appear more fully hereinafter.

Mechanically operated metal drawing presses of the double-action type as presently used employ an outer slide Or blank holder which clamps a sheet metal blank or work piece, and an inner slide which forms, draws or shapes the sheet metal blank after it has been clamped in position by the outer clamping slide. These present presses have proven very satisfactory in general, but they have the disadvantage in that they are unable to produce the desired production quantity principally because the number of opcrating cycles per period of time is limited. The inadequacy of the number of operations or operating cycles per period of time retards the production line and, therefore, limits and prevents rapid production. The reasonsfor 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. These prior mechanical presses are ordinarily operated by a crank or eccentric, and the forming or drawing or" the sheet metal must be consistent with the type of sheet metal which is now available. The present available sheet steel ordinarily has an approximate drawing or flowing speed of about sixty feet per minute; therefore, the actual speed of drawing sheet steel is 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 presses, therefore, have the disadvantage in that the throw of the crank determines the depth of the draw, or the depth of the draw to be performed on the metal determines the throw of the crank to be used. For instance, 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 the blank 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 where the metal drawing operation began. It is then necessary to raise the draw slide an additional twelve inches so that the finished or drawn sheet may be withdrawn from 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. The crank which operates a draw slide to form a twelve inch draw must necessarily have at least a twenty-four inch stroke, and inasmuch as the crank rotates and the crank connections operate in a circular path, the actual circumference of the circle about which the crank connection travels will be diameter times pi (2X3.1415) or approximately 6.2832 feet. The drawing speed of sheet steel as used at the present time having an approximate speed of only sixty feet per minute, the movement of the crank must be limited in speed according to the maximum drawing speed of the metal, viz., sixty feet per minute. Therefore, to effect a twelve inch draw, the peripheral rotative speed of the 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 machine can perform with a crank of this given throw is 60 divided by 6.2832 or approximately nine and one-half (9.54) cycles per minute.

Being limited by the length of the depth of the draw, and the speed at which metal may be drawn, the crank must have a proportional throw and, therefore, it is impossible to increase the production rate of the present 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 hasan approximate drawing speed of sixty feetper minute. 7

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 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 actuating mechanism mounted in the crown of the press and operated by a single drive means to effect simultaneous travel of the blank holder slide and draw slide to the point of blank clamping position of the outer slide and then to maintain the outer slide in its clampin position while the draw slide is moved with respect thereto to effect the draw,

and thereafter to withdraw both slides from operation and return them to their initial positions.

A further object of the invention is the provision of new and improved means mounted in the crown of a metal drawing press for operating the blank holder slide and the inner or draw slide, wherein the number of operating cycles is increased over the conventional mechanically operated presses without exceeding the maximum draw speed of the metal.

A still further object of the invention is the provision of new and improved mechanism lo cated in the crown of a metal working press which includes crank shafts at each side of the press on which are mounted the actuating mechanisms for both the blank holder slide and the inner draw slide and which are so interconnected as to reciprocate both the blank holder slide and draw slide simultaneously between the uppermost position thereof and the clamping position of the blank holder slide and which act to produce a dwell in the blank holder slide while the draw slide is performing the drawing operation.

Still another object of the invention is to provide a novel form of mechanism for operating the draw slide of a mechanical press so as to increase the number of operating cycles per minute by reducing the usual effective vertical movement of the draw slide by eliminating the ordinary crank throw employed in connection with the conventional crank type operated draw slide and causing the draw slide to reciprocate with the blank holder slide during the initial and final portions of the cycle.

A still further and more specific object of the invention is the provision of a crank shaft on each side of the press and located in the crown thereof, whereby a linkage arrangement connected be tween each crank portion of the shaft and the draw slide is effective to reciprocate the draw slide only for the drawing operation thereof. Eccentric means are provided for oscillating a rock shaft having rocker arms connected by novel means to the blank holder slide and the inner or draw slide for the purpose of reciprocating both slides simultaneously at an increased rate of speed during the nondrawing operation.

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

Fig. 1 is a front elevational view of a press embodying the present invention with the cover plate removed therefrom more clearly to illustrate the drive means;

Fig. 2 is a horizontal sectional view along line 22 of Fig. l;

Fig. 3 is an enlarged fragmentary vertical sectional View along line 33 of Fig. 1;

Fig. 4 is a fragmentary elevational view at the top of the press illustrating one of the operating mechanisms for he draw slide at the right-hand side thereof and illustrating one of the operating mechanisms for the blank holder slide at the lefthand side thereof, certain parts being broken away and shown in section for the sake of clarity;

Fig. 5 is a plan view partly insection of one side of the press showing the operating mechanism for the slides;

Fig. 6 is a vertical sectional view along the line 65 of Fig. 5;

Fig. '7 is an elevational view of the actuating mechanism only for. the blank holder slide illustrating the position thereof when the blank holder slide is in uppermost position;

Fig. 8 is an elevational view of the actuating mechanism only of the draw slide illustrating the position thereof when the draw slide is in its uppermost position;

Fig. 9 is an elevational view of the operating mechanism only for the blank holder slide, and similar to Fig.7, but illustrating the position thereof at the beginning of dwell;

Fig. 10 is an elevational view of the operating mechanism only for the draw slide, similar to Fig. 8, but illustrating the position thereof at the beginning of the drawing operation;

Fig. 11' is an elevational view of the operating mechanism only for the blank holder slide, similar to Figs. 7 and 9, but showing the position thereof at the end of the dwell period;

Fig. 12 is an elevational view of the operating mechanism only for the draw slide, similar to Figs. 8 and 10, but showing the position thereof at the completion of the drawing operation; and

Fig. 13 is a motion curve illustrating the relative movement as between the two slides of the press.

The press embodying the present invention includes a frame structure I which may be of any suitable and conventional construction. The frame structure may include a base 2, side frame members 3 and a crown 4. In some instances tie rods 5 with nuts 6 thereon may be usedand shrunk into place for securing theindividual frame members together. It is to be understood, however, that the present invention is applicable as well to presses which do not have a tie rod construction.

The frame members 3 are provided with ways I which cooperate with guides on the outer or blank holder slide 8 to guide the vertical reciprocation thereof. A draw slide 9 is mounted for vertical reciprocation within the blank holder slide 8 and has guide ways thereon cooperating with guides on the blank holder slide to guide the draw slide during the reciprocating movement thereof. The blank holder slide 8 is mounted on a plurality of adjusting screws I0, whereby the slide may be adjusted toward or away from the press bed. Each adjusting screw I8 is received within suitable openings I I properly located on the blank holder slide 8 and is provided with an upper adjusting nut I2 and a lower adjusting nut I3. This construction is conventional and is adapted for manual adjustment of the blank holder slide.

The upper end of each adjusting screw I is provided with spaced side members I4 between which members the lower end of a link I5 may be received. A pin I5 forms a pivotal connection between link I5 and adjusting screw I8, whereby operation of the actuating mechanism to which link I5 is connected will reciprocate the blank holder slide 8.

The draw slide 9 mounted for reciprocation within the blank holder slide 8 is provided with a plurality of recesses I! each for the reception of an adjusting screw I8. The draw slide 9 may be adjusted manually or mechanically as desired. In the illustrated embodiment of the invention the draw slide has been shown as being capable of adjustment by mechanical means.

An internally threaded member I9 threadedly engages the adjusting screw I8 and is disposed above the upper part of the draw slide 9. The threaded member I9 preferably has an enlarged lower portion 28 providing a shoulder 2| engaging a lip 22 on a retaining member 23. The threaded member I9 has a worm gear 24 secured thereto and is caused to rotate by means of a worm 25. Worms 25 are utilized simultaneously to drive worm gears 24 on one side of the press, and a similar arrangement is provided on the opposite side for simultaneously driving similar worm gears so that the adjustment of the draw slide will be constant and prevent the draw slide from being adjusted out of alignment. The adjusting mechanism will be driven by means of motor 26 suitably mounted on the draw slide 9 which drives a shaft 21 having a pinion 28 thereon in mesh with a gear 29 on shaft 38. Shaft 38 is provided with a gear 31 at each end thereof which drives gears 32 and 33 at opposite sides of the press. These gears 32 and 33 operate the worms which drive the worm gears 24 at the four corners of the draw slide for adjustment purposes.

The upper end of each adjusting screw I8 is provided with spaced side members 33 adapted to receive the lower end of a link 34. A pivot pin 35 is received between the sides 33 and within the end of link 34 so that said link is pivotally connected to the adjusting screw I8.

Thus, adjustment of the blank holder slide 8 is obtained by operation of the nuts I2 and I3 on adjusting screw I8 and adjustment of the inner draw slide 9 is obtained mechanically by the means just described in connection with each of the adjusting screws I8. If desired, suitable counterbalancing means may be employed in connection with the adjustment of each of the slides. Such mechanism forms no part of the present in vention and. therefore, need not be described in detail here, it being sufficient to note that one or more cylinders 36 having pistons 31 therein and a piston rod 38 connected to the blank holder slide 8 may have fluid pressure therein to act as a counterbalance when the blank holder slide is adjusted. A similar arrangement may be connected to the draw slide consisting of a cylinder 39 having a piston 40 and piston rod 4I connected to the draw slide 9. The size and number of these counterbalancing devices may vary depending upon the size and type of press with which they are associated. For purposes of illustration, two such devices have been shown as associated with each of the two slides.

' A novel form of mechanism has been devised for the purpose of synchronously driving the blank holder slide and the draw slide from a single drive means so that the effective stroke of the draw slide may be materially lessened over that whichhas been customary heretofore. Part of the same mechanism which reciprocates the blank holder slide also reciprocates the draw slide so that the two slides may move together from the initial position of the blank holder slide to the clamping posit-ion thereof. Additional mechanism also driven by the same drive means then initiates a separate and independent movement of the draw slide with respect to the blank holder slide for the drawingoperation. The specific manner in which this has been accomplished in the present invention embodies a plurality of crank shafts 42 and 43. Crank shaft 42 at the right-hand side of the machine, as viewed in Figs. 1 and 4, may be a continuous shaft extending from front to rear, or it may be formed in two parts, as illustrated in Figs. 5 and 6. Crank shaft 43 at the opposite side of the machine is constructed in an identical manner and also may be formed of a single shaft running from front to rear, or may be formed in two parts, as shown.

The outer end of each crank shaft 42 and 43 at the front and rear of the machine is preferably provided with a gear 44 each having an eccentric portion 45 thereon. Each eccentric portion 45 is surrounded by an eccentric strap 46 provided with an outwardly extending arm portion 41 pivotally secured as at 48 to a rocker arm 49 fixed to a rock shaft 50.

The rock shaft 50 at each side of the machine like the crank shafts 42 and 43 may likewise be continuous from the front to the rear of the press, or they may be split into two parts as illustrated in Fig. 5. Each rock shaft 50 is provided with a suitable number of rocker arms spaced along the length thereof, each associated with a linkage mechanism connected with either the blank holder slide or the draw slide. Fig. 4 illustrates at the left-hand side thereof one of the arrangements which connects one of the rocker arms with the blank holder slide, while at the right-hand side thereof there is illustrated one of the rocker arms and its associated linkage which is connected with the draw slide. In the illustrated press the blank holder slide has been shown as suspended at four points, or at each corner thereof for reciprocation. Each linkage arrangement for each corner of the blank holder slide is identical, and a description of one will suffice for all.

The rock shaft 50, which is preferably a hollow shaft and mounted for rocking movement in suitable bearings 5|, has formed integral therewith a rocker arm 52 preferably positioned adjacent the rocker arm 49 at the outer end of the shaft. The rocker arm 52 extends inwardly and is provided with a pivot pin 53 at its inner end which thereby pivota'lly connects one end of a link 54 therewith. The opposite end of link 54 has a pivot pin 55 which pivotally connects link 54 with a rocker member 56. Rocker member 56 is mounted for rocking movement concentrically on crank shaft 43. Rocker member 56 may be formed in any desired and suitable manner, but is shown herein as having spaced sides with suitable strengthening web 'members, 51 therebetween. Rocker member 56 is provided with a pivot pin 58 at another portion thereof which, in turn, pivotally connects the rocker member with the upper end of a link l5. As rook shaft 50 is caused to rock due to the eccentric movement of the eccentric straps 46 connected thereto by means of rocker arms 49, the connections, including links 54 and rocker members 56, will raise and lower the blank holder slide 8 through the connection therewith of links l5.

It will become evident hereinafter when Figs. 7, '9 andll are considered that during a portion of the rotation of gears 44 carrying the eccentric portions 45, there will be a short period of time during which the rocker members 56 will remain substantially stationary. This is the period during which-the dwell of the blank holder takes place and is clamping the metal work piece while th drawing operation is being performed by the draw slide. It will be understood that in the present embodiment there will be four such link age arrangements 52-56, two on each rock shaft 50 and one for each of the links 15.

Referring now to the righthand side of Fig. 4 wherein there is illustrated the linkage arrangement associated with the draw slide, here again there will b four such arrangements in the press illustrated, one connected with each corner of the draw slide. The number of these linkages is not critical since it depends upon the size and type of press. They are all identical, however, and a description of one will sumce for all.

Adjacent each rocker arm 52 and spaced inwardly therefrom, each rock shaft 56 is provided with another rocker arm 59. The inner end of each rocker arm 59 is pivotally connected to a link 66 by means of pivot pin 6|. One end of link 66 is pivotally connected as at 62 with one arm 63 of a rocker member 54. The rocker member '64 has a second arm 65 extending substantially radially outwardly from the center thereof and spaced from arm 63. This latter arm 65 is pivotally connected to one end of link 66 by means of a pivot pin 61. The other end of link 66 is pivotally connected to th upper end of link 34 by means of pivot pin 61a; Each link 34 is connected at the lower end thereof to the draw slide 9. c

Eachcrank shaft 42 and 43 is provided with a crank portion 66 formed between the spaced cheeks 69, as maybe more clearly seen in Fig. 6. The'rocker member 54 has spaced sides and is mounted for rocking movement concentrically with the crank shaftaxis on the cheeks 69. A link 76 is connected at its upper end with crank portion 68 while the lower end thereof is connected with pivot pin 61a. Cranks 68 and links i being connected with links 34 to the draw slide operate the draw slide only for the drawing operation. The other linkage arrangement connecting the rock shaft with the inner slide acts only to move the draw slide with the blank holder slide during th nondrawing' portion of the press cycle. It will be noted in Fig. 4 that the rocker arms 52 which operate the blank holder slide are disposed inwardly at the same angle as rocker arms .59 connected to the draw slide. Links 54 and '60 are also similarly disposed so that as the rock shafts 56 are caused to rock and oscillate the rocker arms 52 and 56, the blank holder slide and draw slide will be raised and lowered at the same time and will move together as the blank holder slide moves from its initial position to clamping position. The draw slide, however, has an. additional movement with respect to the blank holder slide for performing a drawing operation.

Any suitable drive means may be utilized for driving the actuating mechanism for the two slides. Since both slides are actuated from a common rock shaft, it is only necessary to provid a single drive means for both slides.

A motor H suitably mounted on the press frame may have a shaft I2 on which is mounted a pulley 13. Drive belts 74 may be trained around pulley i3 and pulley F5 on shaft 16. Shaft i6 is provided with a pinion for driving gear l? on shaft '18. Pinion l9 onshaft i8 drives gear 86 on shaft 8|. Gear 86 also meshes with a similar gear 62 on shaft 63. Shaft 3i has mountedthereon a gear 84 in mesh with main drive gear 44-on shaft 42. Shaft 83 has pinion 85 thereon which drives main gear 44 on shaft 43 at the opposite ide of the press. Thus, drive gears 44 at opposite sides of the press are caused to rotate .simultaneously at the same rate of speed in opposite directions for actuating the eccentrics 7 associated therewith and for operating the eccentric straps 46. The eccentric straps 46 through their respective connections with links 49 cause the rock shafts 56 at each side of the press to oscillate simultaneously and carry with them the rocker members 52 and 56 connected with the blank holder slide and draw slide, respectively.

The sequence of operations is clearly. illustrated in Figs. 7 to 12, inclusive. Referring now to these figures of the drawings, Fig. 7 illustrates the position of the rocker arms 52, links 54, rocker member 56 and link l5 in their respective positions when the blank holder slide is in its initial upper position. Fig. 8 illustrates the position of each rocker arm 59, link 66, rocker member 64 and links 66, i6 and 34 in their respective positions at substantially the upper initial position of the draw slide.

As gears 44 are caused to rotate in the direction indicated by the arrows, the eccentric straps 46 will cause the rock shafts 56, carrying rocker arms 52 and 59, to oscillate to the position shown in Figs. 9 and 10. In this latter position Fig.9 shows' the respective parts where the blank holder slide has been moved downwardly to clamping position and is at the beginning of its dwell.

Fig. 10 shows the position of the draw slide linkage arrangement in the position thereof at the beginning of the drawing operation. From these figures it will be evident that further rocking movement of rocker member 56 Will be very slight because links 54 and rocker members 52 will be passing over dead center. Continued rotation of gears 44 will permit rocker member 56 to remain substantially stationary and thus cause a dwell in the blank holder slide. Such a dwell would also be caused in the draw slide except for the additional movement imparted thereto by reason of cranks 68. Fig. 10 shows crank 68 beginning its downward movement, and Fig. 12 shows crank 68 in its lowermost position with Q link 34 and draw slide connected therewith in the lowermost position at the end of the draw.

Fig. 11 shows the position of eccentric straps 46 at the end of the dwell where they are about to rotate the rock shaft 50 upwardly. This motion continues until the various parts of the linkage mechanism for the blank holder slide return to the positions shown in Fig. 7.

The draw slide is also caused to move upwardly at the end of the blank holder slide dwell because of the connection with the draw slide of the linkage mechanism also actuated by oscillation of the rock shaft 50. However, upward movement of each crank 68 from the lowermost position thereof in Fig. 12 also is effective to elevate the draw slide so that it is returned to its upper original position, not only by reason of the movement of crank 68, but also because of'the linkage connection with rock shaft 50.

Since the draw slide is raised and lowered by substantially the same mechanism which reciprocates the blank holder slide, the linkage mechanism can be designed to cause this movement at a greatly increased rate of speed over that which has heretofore been possible with a common crank arrangement. The crank throw or eccentricity of the crank for the draw slide need be only six inches to perform a twelve inch draw as compared with substantially twelve inches in the usual crank operated press. Since the throw of the crank is greatly reduced, it follows that the number of cycles per minute can be proportionally increased without exceeding the safe draw speed of the metal. Increase in the number of cycles per minute thereupon is effected to increase production greatly.

While the press of the present invention has been particularly described wherein the drive mechanism for the slide actuating means is in the crown of the press, it is contemplated that similar results may be obtained if the actuating mechanism for the slides and the drive therefor are located in the base of the press.

It is also contemplated that while it is preferable that the press bed be in the lower part of the press and the blank holder and draw slides be movable thereabove, it would be possible to reverse these parts whereupon the work piece may be place-d initially on the blank holder slide and elevated to be clamped against the upper stationary bed. The draw slide wouldthen move upwardly to perform the drawing operation rather than downwardly as illustrated herein.

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.

The invention is hereby claimed as follows:

1. A mechanical metal drawing press comprising a frame structure including a base, a crown and side members, a blank holder slide mounted for reciprocation within said frame, a draw slide mounted for reciprocation within said blank holder slide, a rock shaft and a crank shaft mounted in said frame, means for driving said shafts, linkage mechanism including a part mounted for pivotal movement with respect to said frame drivingly connecting the rock shaft with said blank holder slide, a link connected to the draw slide, a second linkage mechanism including apart mounted for pivotal movement with respect to the frame drivingly connecting is the rock shaft with said link, and a second link connecting the crank with said first link, said shafts, drive means, links and linkage mechanisms being so coordinated that operation of the rock shaft 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 crank will effect further move ment of the draw slide during the dwell of the blank holder slide to perform the drawing operation.

2. A mechanical metal drawing press compris ing a frame structure including a base, a crown and side members, a blank holder slide mounted for reciprocation within said frame, a draw slide mounted for reciprocation within said blank holder slide, a crank shaft in said frame, means for driving said crank shaft, linkage mechanism including a part mounted for pivotal movement with respect to said frame and drivingly connected to said blank holder slide, a link connected to the draw slide, a second linkage mechanism connected to said link and terminating in a part mounted for pivotal movement with respect to the frame, operating means connected to said pivotally mounted part for oscillating said part between two angular positions, drive means for said first linkage mechanism, and said operating means, and a second link connecting the crank with said first link, said crank shaft, drive means, links and linkage mechanisms being so coordinated that operation of said drive means 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 crank will effect further movement of the draw slide during the dwell of the blank holder slide to perform the drawing operation.

3. A mechanical metal drawing press comprising a frame structure including a base, a crown and side members, a blank holder slide mounted for reciprocation within said frame, a draw slide mounted for reciprocation within said blank holder slide, a rock shaft and a crank shaft mounted in said frame, means for driving said shafts, operating mechanism mounted for movement with respect to the frame drivingly connecting the rock shaft with said blank holder slide, a link connected to the draw slide, a linkage mechanism including a part mounted for pivotal movement with respect to the frame drivingly connecting the rock shaft with said link, and a second link connecting the crank with said first link, said shafts, drive means, links, operating mechanism and linkage mechanism being so coordinated that operation of the rock shaft 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 crank will effect further movement of the draw slide during the dwell of the blank holder slide to perform the drawing operation.

4. A mechanical metal drawing press comprising a frame structure including a base, a crown and side members, a blank holder slide mounted for reciprocation within said frame, a draw slide mounted for reciprocation within said blank holder slide, a rock shaft and a crank shaft mounted in said frame, means for driving said shafts, linkage mechanism including a part mounted for pivotal movement with respect to said frame drivingly connecting the rock shaft with said blank holder slide, a link connected to the draw slide, operating mechanism mounted for movement with respect to the frame drivingly connecting the rock shaft with said link, and a second link connecting the crank with said first slide to perform the drawing operation.

' 5. ,A mechanical metal drawing press comprising a framestructure including a base, a crown and side members, a blank holder slide mounted for reciprocation within said frame, a draw slide mounted for reciprocation within said blank holder slide, a rock shaft and a crank shaft mounted in said frame, means for driving said shafts, operating mechanism mountedfor movement with respect to the frame drivingly connecting the rock shaft with said blank holder .dwell, and that operation of said crank will effect further movement-of the draw slide during the dwell of the blank holder slide to perform the drawing operation.

6. A mechanical metal drawing press comprising a frame structure including a base, a crown and side members, a blank holder slide mounted for reciprocation within said frame, a draw slide mounted for reciprocation within said blank holder slide, a rock shaft and a crank shaft mounted in said frame, means for driving said shafts, linkage mechanism including a part mounted for pivotal movement with respect to said frame drivingly connecting the rock shaft with said blank holder slide, a link connected to the draw'slide, a rocker member mounted on said frame, operating means connecting said rock shaft with said rocker member, a second link connecting said rocker member with said first link,-and a third link connecting the crank with said first link, saidshafts, drive means, linkage mechanism, rocker member, operating means, and links being so coordinated that operation of the rock shaft will move both slides toward the bed,'bringingtheblank holder slide into clamping position and causing the same to dwell, and

that operation of said crank will effect further movement'of the'draw slide during the dwell of the blankholder slide to perform the drawing operation. V

'7. A mechanical metal drawing press comprising a frame structure including a base, a

crown and side members, a blank holder slide mountedfor reciprocation within said frame, a

i2 link connecting the other arm of bell crank with said first link, and a third linkconnecting the crank with said first link, said shafts, drive means, linkage mechanism, bell crank operating means, and links being so coordinated that operation of the rock shaft 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 crank will effect further movement of the draw slide during the dwell of the blank holder slide to perform the drawing operation. I

8. A mechanical metal drawing press comprising a frame structure including a base, a crown and side members, a blank holder slide mounted for reciprocation within said frame, a draw slide mounted for reciprocation within said blank holder slide, a rock shaft and a' crank shaft mounted in said frame, means for driving said shafts, a plurality of rocker arms secured on said rock shaft, operating mechanism driving ly connecting certain of said rocker arms with said blank holder slide, a link connected to the draw slide, a second Operating mechanism drivingly connecting others of said rocker arms with said link, and a second link connecting the crank with said first link, said shafts, drive means, operating mechanisms, and links being so coordinated that operation of the rock shaft 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 crank will effect further movement of the draw slide to perform the drawing operation.

9. A mechanical metal drawing press comprising a frame structure including a base, a crown and side members, a blank holder slide mounted for reciprocation within said frame, a draw slide mounted for reciprocation within said blank holder slide, a rock shaft and a crank shaft mounted in said frame, means for driving said shafts, operating mechanism mounted for movement with respect to the frame driving'ly connecting the rock shaft with said blank holder slide, a link connected to the draw slide, a second operating mechanism mounted for movement with respect to the frame drivingly connecting the rock shaft with said link, and a second link connecting the crank with said first link, said shafts, drive means, links and operating mecha nisms being so coordinated and arranged that operation of said rock shaft 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 crank will effect further movement of the draw slide during the dwell of the blank holder slide to perform the drawing operation, the above named group of elements being further arranged and coordinated so that said first and second named links move from an angular relationship to a substantially straight line relationship during the drawing stroke, and the length of drawing stroke is greater than the throw of the crank.

' EINAR K. JOHANSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,133,444 Glasner Oct. 18, 1938 2,257,383 Johansen Sept. 30, 1941

Images