US2346214A - Platen control device - Google Patents

Description

April 11,*1944. P. E. FLOWERS PLATEN CONTROL DEVICE Filed May v, 1941 2 sheets-sheet 1 lllll I 1 .w o willi/1 D l. O 5 2 u.. u. l-u IU 3 a. 5 u. w n .l 8 & n s u. mm .WIM 1V N 2 m o J V fr l 3 o o u w @FM v s w j 3 INVEN ron 'PAuL E`..F'L,ow s y :B AfVFQRhuaYA Apnl 11, '1944.

PLATEN CONTROL DEVICE Filed May v. 1941 2 Sheets-Sheet 2 .Il Il 2 INVEN-ron 'PUL E MERS Mk-f /aaaMlv l ATTQRN: ys

Patented Apr. 1l, 1944 i PLATEN CONTROL DEVICE Paul E. Flowers, Mount Gilead, Ohio, assignor to The Hydraulic Development Corporation, Inc., Wilmington, Del., a corporation of Delaware Application May 1,1941, serial No. 392,319

s claims. v(ci. io-'52) This invention relates to hydraulic presses and,

in particular, to controlling mechanisms for the manual control of press platens.

Such controlling mechanisms as heretofore known consisted substantially'of a hand wheel operated spindle connected by a linkage with the ow control member of a hydraulic pump supplying pressure iluid for actuating the press platen.

While these known controlling mechanisms are w quite satisfactory for the purpose of setting-up a press for the intended work, they do not 'meet the requirements of modern industries as to speed and flexibility in operation. In particular, they do not allow fast traverse movement of the press platen.

Accordingly, it is an object of the invention to provide a manually operable controlling mechanism for 'the platen of a press which, although simple in construction, will overcome the drawbacks above referred to in connection with platen controlling mechanisms heretofore known.

It is another object to provide a manually operable controlling mechanism which will make it possible to raise and lower the platen of a press rapidly, and also absolutely and instantly to control the movement of the press platen after it has contacted the work piece.

A further object of the invention consists in the provision of a controlling mechanism in which a simple shifting movement of a hand lever may at any time during a pressing cycle bring the press platen instantly` to a stop or to cause a fast or slowed down movement of the platen in either direction of its movement.

It is still another object of the invention to provide a controlling mechanism of the type set forth in the preceding paragraph, in which thefpress platen may be caused to move a predetermined distance by merely shifting the hand lever through a predetermined angle.

These and other objects and advantages of the invention will appear more clearly from the following specifcation in connection with the ac- General arrangement The controlling mechanism of the present invention' substantially comprises a hand lever operatively connected by a linkage on one hand with the flow control member ofa variable delivery Dump supplying pressure fluid for advancing the press platen and, on the other hand, with a uid containing control cylinder communicating with the fluid tank of the press and having reciprocably mounted therein a plunger connected'with the press platen. Communication of the fluid tankand the control cylinder is controlled by a normally open valve adapted to be closed by the hand lever.

By shifting the hand lever and maintaining the valve open, fast movement of the platen may be V obtained in either direction, whereas when the valve is closed, shifting movement of the hand lever is adapted to cause slow movement of the platen in the desired direction.

Structural arrangement The press shown in the drawings comprises a press bed I and apress head 2 connected with each other by means of a column or frame 3. The presshead2 comprises a press cylinderd having reciprocably mounted therein a double-acting press piston 5-.with a piston rod 6 connected to the press platen 1.

. The cylinder 4 is adapted to communicate through a surge valves with a fluid reservoir or surge tank 9 mounted on top of the press head -2. Arranged in the tank 9 is a main cylinder release and pump by-pass valve Ill, which is adapted to communicate through conduits I I and I2 with the surge valve 8.

'Ihe surge valve 8 and the main cylinder release and pump by-pass valve I0 do not form a part of the present invention and for a more detailed description thereof reference may respectively be hadl to U.' S. Patent No. 2,193,248 and U. S. Patent No. 2,268,205. i

The purpose of the surge valve consists in prerllling the press cylinder 4 when the press piston 5 moves downwardly by gravity, while the main cylinder release and pump by-pass valve I0 is provided for the puropse of relieving the pressure on the piston 5 for facilitating the initiation of the retraction stroke of the platen l.

Also connected with the main cylinder release and pump by-pass v alve I0 is a conduit I3 leading to a conduit I4, which on one hand` communicates with the upper portion of the press valve|8 connected with the conduit I2 is provided for admitting fluid. from the tank 8 into the conduit I2, which communicates with the lower portion of the press cylinder 4 and is connected by a branch line I9 with one side of the variable delivery pump 20. The other side of the variable delivery pump 2|! is connected with the upperportion of the press cylinder 4 through a conduit 59. The variable delivery pump may be of any standard type, preferably of the type set forth in U. S. Patent No. 2,184,665.

The iiow control member (not shown) of the pump 20 and, thereby, the delivery and direction of delivery of the pump is controlled by the valve rod 2| which is pivotally connected by a link system. generally designated 22, with a bell crank lever 23 shiftable about'the pivot 24 and adapted to engage a collar 25 adjustably mounted on a push rod 26. Also adjustably mounted on the push rod 26 is a collar 21 adapted to be engaged by the arm 28 connected tothe platen 1. Also connected with the platen arm 28 is a plunger 28 reciprocably mounted in a control cylinder 30 and passing through packing material 3| and a gland 32 connected with the upper portion of the control cylinder 30.

The control cylinder 30 is slidably mounted in guiding members 33 and 34, which are connected to the column or frame 3. The lower side of the guiding member 33 is engaged by a spring 35, the lower end of which is supported by a collar 36 adiustably mounted on the control cylinder 30 by means of an adjusting screw 31. A spring 3B, preferably identical to the spring 35, is mounted between the guiding member 34 and a collar 39 likewise adjustably mounted on the control cylinder 30. The springs 35 and 38 tend to hold the control cylinder 30 in an intermediate position. The space between the collars 36 and 35 is engaged by a forkshaped portion of a lever arm 4|) carrying a pivot 62 which is slidably engaged by the forked portion 53 at the lower end of the push rod 26. The length of the forked portion 63 is such that the pivot 52 is always engaged thereby, even when the pivot 62 is in its lowermost position and the push rod 28 is in its uppermost position.

The lever arm 40 is pivotally connected with a link 4|, which in its turn is pivotally connected to a lever 42 shii'table about the pivot 43. The other end of the lever 42 is linked to a link 44, which in its turn is pivotally connected to an arm 45 rotatably connected with a shaft 43 (Figure-5). IIhe front end of the shaft 45 is slotted and has mounted therein a control lever 41 shiftable about a pin 48 extending across the slot 43 in the shaft 46.

The lower end of the control lever 41 broadens out into a contact member 5|! which is adapted to engage a normally open switch 5| so as to cause the latter to close the `venergizingl circuit for the solenoid 52 which, when energized, closes the shutoff valve 53 adapted to effect or interrupt hydraulic communication between the flexible conduit 54 connected with the lower portion of the control cylinder 30 and the conduit 55 leading to the tank 9. The valve 53 in its normal or open position allows fluid from the tank 5 to ll the control cylinder 30 so that the latter is normally filled with fluid. Y

As will be clear from Figure 5, the control lever 41 may selectively be shifted toward the right or the left without actuating the switch 5|. If desired, the control lever 41 may also be shifted about the pin 48 so as to close the switch 5| and then toward the ieft'vor the right, while maintaining the switch 5| closed. The control lever 41 is connected to two centering springs 56, 51,

which tend to disengage the control lever 41 from the switch 5|, and to return the control lever 41 into the position shown in Figure 2.

To enable the operator to control the angle through which the control lever 41 is shifted, a calibrated scale 58 may be provided.

. ,Operation Suppose that all parts of the press occupy the position shown in Figures 1 and 2, and that it is now desired to start a pressing cycle. To this end, the operator shifts the control lever 41 toward the left, for instance, into the left position indicated in Figure 4, without shifting the lever 41 about the pin 48.

As a result of this movement the shaft 46 is rotated in anti-clockwise direction, thereby causing the lever arm 40 to shift about the front end thereof as a pivot into the position of Figure 3. which movement in its turn causes upward movement of the push -rod 26, thereby shifting the valve rod 2| toward the right with regard to Figures land 2. As a result thereof, the pump` 20 is shifted into forward stroke position and delivers fluid through the conduit 59 into the upper portion of the press cylinder 4, while withdrawing fluid from the lower portion of the press cylinder 4 through the conduit I8.- The platen 1, therefore. moves downwardly by gravity as fast as fluid-is withdrawn from the lower portion of the press cylinder 4, while the fluid delivered by the pump 20 into the upper portion of the press cylinder 4 is supplemented by fluid from the tank and passing Vthrough the surge valve 8. In this way, fast traverse movement of the platen 1 is obtained by a single shifting movement of the control lever 41.

While the platen 1 thus slides downwardly, the plunger 29 enters the control cylinder 30 and expels fluid therefrom, which ilows through conduit 54, shutoff valve 53 and conduit 55 into the tank 9. Since no force is acting on the control cylinder 30 andthe centering springs 35 and 38 maintain the cylinder 30 in intermediate position, no movement of the control cylinder 30 takes place.

Supposing now that the press platen 1 approaches the work piece, and that it` is desired to slow down the platen movement. To this end the operator does not return the control lever 41 to its starting position, but shifts the latter from its present position about the pin 48, so that the contact member of the control lever 41 engages the switch 5| and closes the same. thereby energizing the solenoid 52. Energization of the solenoid 52 closes the shutoff valve 53 which in its turn now interrupts communication between the fluid tank 9 and the control cylinder 30. Inasmuch as no fluid can now escape from the control cylinder 30 while the downward movement of the plunger 29 continues. the pressure exerted upon the uid entrupped in the control cylinder 30 acts upon the latter and moves the control cylinder 30 downwardly against the thrust of the centering spring 38. While the control cylinder 30 thus moves downwardly, the` arm 40 shifts about the pivot 60 connecting the link 4| with the arm 40 in anti-clockwise direction so that the push rod 2B is moved downwardly by the bell crank lever 23 which is continuously urged against the collar 25 by the link system 22 acted upon by a spring in the servomotor 6| of the variable delivery pump 20. As a result, the valve rod 2| is shifted toward the left with regard to Figures 1 and 2,. thereby moving the pump 26 to neutral or no delivery position.

The press platen, therefore, gradually decreases its downward speed and if the control lever.41

but in an inclined position and, similarly, the

lever arm 40 is inclined, while the spring 38 is compressed as shown in Fig. 4.

If it is now desired to slowly move the platen ,A

1 further downwardlyto effect a pressing operation, the control lever 41 is further shifted toward the left. As the press 'platen 1 had previously come to a standstill,it will be clear that the last mentioned further leftward movement of the control lever 41 causes the arm 40 to shift in anti-clockwise direction about the left end of the arm 46, since, at this time, the cylinder 3|) is stationary. Consequently, the push rod 26 is lifted and the valve rod 2| is moved toward the right so as to place the pump again on forward stroke position.

The platen 1, therefore, is moved downwardly by pressure fluid delivered from the pump 26 into the upper portion of the press cylinder 4 and, in the same manner as previously described, the control cylinder 30 moves downwardly until the arm 40 has shifted in anti-clockwise direction about the pivot 56 to such an extent that downward movement ofthe push rod 26 has enabled the valve rod 2| to return to its previous position shown in Figure 2, in which the pump 20 is in neutral or no delivery position so that the platen 1 again comes to a halt.

In this way a gradual inching movement of the platen 1 can be'obtainecL and it will be clear that a leftward movementof the control lever 41 by a predetermined degree causes the platen 1`to advance by a predetermined extent, provided, of course, that the contact member 50 of the control lever41 holds the switch 5| closed. In other words, the operator can obtain a predetermined movement of the press platenv by shifting the control lever through a predeter- 50 mined angle.

If, forfsome reason, a slight and slow retraction movement of the platen 1 is desired,

the operator merely shifts the control lever 41 from the position in which the platen 1vlast 5 came to a standstill toward the right, thereby moving the push rod 26 downwardly and the valve rod 2| further toward the left beyond the position shown in Figure 1. which puts the pump 20 on retraction stroke. Pressure fluid is then delivered by the pump 20 through conduit vI9 into the lower portion of the press cylinder 4, while uid is withdrawn from the upper portion of the press cylinder 4 to the pump 20.

The platen 1 and, consequently, also the plunger 29 n`ow move upwardly and, inasmuch as the shuto valve 53 is still closed, the pressure in the control cylinder 30 is relieved so that the spring 38 acting upon the collar 39 causes the control cylinder 3|) to follow (the upward movement of the plunger 29. During this` upward movement of the control cylinder 30, the lever arm 40 shifts in anti-clockwise direction about the pivot 60, thereby lifting the push rod 26 n and moving the valve rod 2| toward the right.

When the valve rod 2| has reached the position shown in Figure 2, the pump 20 is again in neutral position Vand the press comes to a halt. The platen 1 may now again be put'on 5 forward stroke to a desired extent by shifting the lever 41 from its last position toward the left, in which case the forward movement of the platen previously described will be effected.

If it is desired to quickly return the platen l to its, retracted position, the operator shifts the "lever 41 fromI its present position toward its extreme right position, while the contact member 50 still engages the switch 5|. lever 41 has reached its extreme right position, it is shifted'about the pin 48 so as to release the switch The release of the switch 5| causes the latter to op'en and, thereby, to deenergize the solenoidl 52 so that the shutoff valve 53 again establishes communication between theA The movement of the control valve lever 41 to,

its extreme right position causes a rotation of the shaft 46 in clockwise direction and permits the spring in the servomotor 6| of the pump 20 to shift the valve rod` 2| to its extreme left position. while the push rod 26 is pushed downwardly.

The pump 26 is then in full delivery retraction stroke position and delivers pressure fluid through conduit |9 into the lower portion of the press cylinder 4 so that the platen 1 rapidly moves upwardly. When the platen 1 rea-ches the end of its upward movement, the platen arm 28 engages *the collar 21 and` lifts the push rod 26 into the position of Figure 2, thereby returning the pump 2D to its neutral or no delivery position. If now the control lever 41 is released, the springs 56, 51 will return it to the position shown in Figure 2. This movement will not affect the push rod 26 since, at the time the push rod 26 is lifted into the position of Figure 2, and the control lever 41 is in its lextreme right position, the pivot 62 is at the lower end of the forked portion 63 of the push rod 25. the control lever 41 moves from its extremel right position to the position in Figure 2, the pivot 62 moves from the lower end of the forked portion 63 of the push rod 26 to the upper end of the forked portion 63, where it just engages the collar 5 64 of the push rod 26. Y

The present invention is of particular importance in connection with forging presses, such as the horn press shown in the drawings. However itis, of course, understood that the present invention is by no means limited to presses of this type. As will be clear from the above, the controlling mechanism of therpresent invention enables, at any time of the cycle,` complete control of the 65 platen and makes it possible to advance the platen by predetermined minute distances; as weil as to move theplaten at high speed during the forward and also during the retraction stroke thereof.

It will also be clear from the foregoing description that the platen may be instantly stopped at any time of the cycle.` If, for instance. the platen 1 4is moving downwardly at high speed while valve 53 is open and cylinder 3|) is in the position of Figure 2, it is merely necessary to return the control lever 41 to the position of Figure 2, to

When the In other words, while the upper end ofclosed, will pull th`e right end of the lever arm I downwardly while the left end of lever arm 40 is pulled downwardly by the now downwardly moving cylinder 30. As a result thereof, the spring in the pump servomotor presses push rod 2S downwardly, thereby shifting the pump 2Q to neutral position and stopping the platen 1.

It will be understood that I desire to comprehend within my invention such modifications as come within the scope of the claims.`

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is: 1

1. In a hydraulic system, a main plunger having associated therewith fluid operable advancing and retracting means for reciprocating said plunger, a iiuid source for supplying pressure fluid to said advancing and retracting means for actuating the same, control means for controlling the delivery of fluid from said fluid source to said advancing and retracting means, manually operable means operatively connected with said control means for varying the delivery of said fluid source, .follow-up means operatively connected .with said control means and said manually operable means for causing said plunger to stop after a predetermined travel thereof corresponding to a predetermined but variable setting of said manually operable means, said follow-up means including a movable cylinder, a piston therein connected to move in unison with said main plunger, and a valve controlling the flow of fluid to and from said cylinder whereby said cylinder will move with said plunger-when said valve is in one position and will remain stationary when said valve is in another position, said follow-up means further including a lever system connecting said cylinder and said control means, said lever system being connected to operate said valve.

2. In a hydraulic press, a press plunger, a reversible variable delivery pump for supplying pressure uid to said plunger to actuate the same, servornotor means associated with said pump for controlling the delivery and the direction of delivery of said pump, a manually operable lever mechanism connected with said servomotor means for actuating the latter, a reciprocable fluid filled cylinder, a control plunger reciprocable in said cylinder and movable in unison with said press plunger, said cylinder being operatively connected with said lever mechanism for actuating said servomotor means in response to the position of said lever mechanism and the movement of said press plunger, and valve means operable by*u said lever mechanism for selectively allowing or preventing escape of fluid from said 1 cylinder during the working stroke of said press plunger, to thereby respectively prevent or establish positive driving connection between said plunger and said cylinder.

3. In a hydraulic circuit, Va fluid operable main plunger, a fluid source for supplying pressure fluid to said plunger, control means for controlling the supply andthe direction of flow of uid from said uid source to said plunger, a reciprocable iluid iilled cylinder connected to actuate said control means, movable plunger means associated with said main plunger and, cooperating with said cylinder so as selectively to vary the pressure condition of the iiuid therein, valve means operable independently of said control means for selectively entrapping fluid in said cylinder or releasing iiuid therefrom while said main plunger is in lmotion, and manually operable means operatively connected with said control means for actuating the same, said manually operable means also being adapted selectively to eilect operation of said valve means.

4. In a hydraulic press, a press plunger, a iiuid source to supply pressure iiuid to said plunger for actuating the same, a fluid filled container reciprocably mounted on the frame of the press, a fluid storage tank on the head of the press, valve means for selectively establishing or interrupting communication between said tank and said container, a control plungerconnected to said press plunger and reciprocable in said container, control means for varying the supply of pressure iiuid from said iiuid source to said press plunger, a link system operatively connected with said control means and said container, and a lever manually operable for selectively actuating said link system with or without simultaneously actuating said valve means.

5. In a hydraulic press, a press plunger having associated therewith fluid operable yadvancing and retracting means, a reversible variable delivery pump for supplying pressure fluid selectively to said advancing or retracting means, servomotor means for varying the supply of pressure iiuid from said pump to said advancing and retracting means, control means for actuating said 4servomotor means, a fluid storage tank, a reciprocable fluid iilled container connected to move said control means and having reciprocably mounted therein a control vplunger connected to saidA press plunger, manually operable means. for actuating said control means, valve means operable by said manually operable means for selectively eilecting hydraulic communication between said tank and said container, and yielding means urging said container into an intermedlate position and adapted to allow reciprocative movement4 of said container in response to the movement of said control plunger.

6. In a hydraulic press, a press platen having associated therewith fluid operable means for advancing and retractng said platen, a uid pressure source for supplying pressure fluid to said uid operable means for actuating the latter, controlling means for controlling the supply of pressure fluid to said uid operablemeans, a fluid storage tank, a reciprocable cylinder, yielding means for continuously urging said cylinder into an intermediate position, valve means operable selectively to eiect or interrupt hydraulic communication between said tank and said cylinder, a control plunger connected to said platen and reciprocable invsaid cylinder, link means operatively connected with said cylinder and said controlling means for actuating the latter, and a hand lever shiftable in one plane for controlling said valve means and in a second plane for actuating said link means to control the movement of said platen.

PAUL E. FLOWERS.

Images