US2484908A

US2484908A - Platen leveling

Info

Publication number: US2484908A
Application number: US759666A
Authority: US
Inventors: Howard M Purcell
Original assignee: HPM Development Corp
Current assignee: HPM Development Corp
Priority date: 1947-07-08
Filing date: 1947-07-08
Publication date: 1949-10-18
Anticipated expiration: 1966-10-18

Description

H. M. PURCELL PLATEN LEVELING Oct. 18, 1949.

4 Shets-Sheet 1 Filed July 8, 1947 VIIIIII mvzu'ron HOWAXD M. 'PURe'JELL ATTORNEYS Oct.

Filed July 8, 1947 H. M. PURCELL PLATEN LEVELING 4 SheetsSheet 2 ATTORNEYS Oct. 18, 1.949. PURCELL 2,484,908

PLATEN LEVELING Filed July 8, 1947 4 Sheets-Sheet 3 ATTORN i Y8 Oct. 18, 1949.

H. M. PURCELL $484,908

PLATEN LBvELme Filed July 8, 1947 4 Sheets-Sheet 4 INVENTOR Y HOWARD M. PURCELL ATTORNEYS Patented on. 18, 1949' PLATEN LEVELING Howard M. Purcell, Philadelphia, Pa asslgnor to H-P-M Development Corporation, Wilmington, Del., a. corporation of Delaware Application July 8, 1947, Serial No. 759,668

15 Claims. (Cl. 60-97) This invention relates to presses, and particularly to multi-point presses wherein there are a plurality of points at which power is applied to the press platen for moving it.

The particular object of the present invention is to provide an improved arrangement for maintaining a multi-point press platen level.

Still another object of this invention is to provide a means for maintaining the platen of a multi-point press level and which utilizes a minimum of auxiliary equipment in accomplishing this result.

Still another object of this invention is the provision of a mechanism for maintaining a multi-point press platen level which is substantially instantaneous in operation.

Still another object is to provide a means for maintaining a press platen level which may readily be installed on the platen of any press.

It is also an object of this invention to provide in combination with a hydraulic press having a plurality of spaced rams acting on a platen, a means for controlling the delivery of fluid to the said rams whereby the said platen remains level at all times.

These and other objects and advantages will become more apparent upon reference to the following description taken in connection with the accompanying drawings in which:

Figure l is a diagrammatic view of a twopoint hydraulic press having a platen leveling mechanism according to this invention:

Figure 2 is a fragmentary view as showing a somewhat modified construction to be utilized in connection with the arrangement of Fi ure 1;

Figure 3 is a view similar to Figure l but showing a somewhat different arrangement wherein separate pumps are employed for supplying fluid to the platen actuating rams:

Figure 4 is a detailed view showing one part of the pump control linkage of Figure 3;

Figure 5 is a diagram of the electrical control circuit for the arrangement of Figure 3;

Figure 6 is a view showing still another form of this invention and wherein the control of the platen is accomplished through pressure;

Figure '7 is a perspective view showing how this invention can be applied to a press having four rams connected with the platen;

Figure 8 is a diagrammatic view showing this invention applied to a long platen having a plurality of rams spaced therealong; and

Figure 9 is a perspective view showing a simplified form of this invention.

General arrangement According to this invention the platen of a press having a plurality of actuating means for the platen is maintained level by means of a flexible member such as a cable which is connected between the press head and press bed and which passes across the press platen. The flexible member is anchored on one of the head or bed and there are pulleys or other journaling means on the platen and the other of said head or bed whereby tilting movement of the platen will produce relative movement between the flexible member and the one of said head or bed on which it is journaled. This relative movement may be resisted by heavy yielding means which normally support the weight of the platen or may be employed for actuating hydraulic or electrical means which control the delivery to the actuating means for the press platen to set up forces therein which will restore the platen to its level condition.

Preferably, the actuating means for the press platen are hydraulic motors such as rams and the means for maintaining the platen level, and which are under the control of the flexible member, comprise fiow dividing valves, pressure control valves, or delivery control means for pumps supplying the said rams.

Structural arrangement Referring to the drawings, the press shown in Figure 1 comprises a bed It and a head i2 which is connected with the said bed by the strain rods it. A platen it is slidable on strain rods it between the head i2 and bed it. The platen is actuated by a pair of rams it which extend into the cylinder 253 which are preferably integral with the head 15?.

A pump 22 is connected by a conduit 2d with the retracting means of the rams i8 and, by a conduit is with the inlet of a flow dividing valve 28. The flow dividing valve 28 has twoservice ports which are connected by the conduits at with the advancing means of the rams iii. The valve 28 also has therein a valve member 32 which in its center position offers equal restriction to the fluid fiow from the conduit 26 to each of the conduits 3t. Upon movements in either direction the valve member 32 decreases the restriction to flow to one of the conduits 3t while increasing the restriction to flow to the other conduit 3t.

For pre-fllling the advancing means for the rams during their initial downward movement,

ace-secs and for exhausting the said advancing means during the retracting movement of the rams, there are preferably provided surge valves 84 which connect the said advancing means with the reservoir 36 in response to suction in the ad-- vrncing means or in response to a predetermined pressure acting in the retracting means of the rams. A check valve 38 opens from the reservoir 38 into the conduit 25 for supplying makeup fluid to the pump 22 during the working stroke of the rams 88.

Control of the pump delivery is had by a linkage to which includes the vertical rod t2 that passes through an arm H on the platen it and has as its upper end a solenoid armature arrangement as. Energization of the solenoid Ml will lift the rod 52 and through the linkage QB place the pump 22 in position to deliver into the conduit 26. De-energizing of the solenoid dd permits the springs :16 to move the rod 32 downwardly and to place the pump in position to deliver to the conduit 25.

For actuating the valve member 32 of the flow dividing valve 28 there are provided a pair of flexible cables indicated at 68 and 50. The ends of these cables are anchored as at 52 and 5 8 to the bed I and pass upwardly therefrom to the pulleys 58 and 53 on the platen I5. The cables then pass across the platen in opposite directions to the

pulleys

60 and 82. Then the cables extend upwardly and over the pulleys M and 66 carried by the press head. The ends of the cables are then fastened together by a suitable fitting 8B. The anchors at 52 and d are preferably adjusted to hold the cable perfectly taut throughout its length.

The valve member 32 of the valve 28 is connected by the lever which is pivoted at 72 with the member 68. A pin and slot arrangement at M interconnects the lever and member for simultaneous movements.

It will be apparent that, should the right end of the platen i6 tilt downwardly as viewed in Figure 1, the length of cable from the anchor 52 over the pulley 56, pulley 60, and extending upwardly to pulley 68, will become greater than the length of the cable extending from the anchor 55, the pulley 5B, pulley 62 and up to pulley 68. Accordingly, there will be a movement toward the right of the horizontal reach of the cable extending between the

pulleys

64 and 66 and also a movement to the right of the member 68 and the lower end of the lever 10. This brings about a movement to the left of the upper end of the member Ill and of the valve member 32 which operates to restrict the flow of fluid from the conduit 26 to the right hand conduit 30, and to reduce the restriction to flow from the conduit 26 to the left hand conduit 30. The pressure acting on the right hand ram I8 is therefore less than that acting on the left hand ram I8 and unbalanced forces are generated thereby which tend to restore the platen I6 to its level condition.

It will be apparent that either direction of tilting of the platen I6 from level will be fol lowed by the setting up of unbalanced forces thereon tending to bring it back to its level condition.

The ends ofthe cables 48 and 50 may be adjusted at their anchors 52 and 54 respectively in order to pre-set the valve 28 to bring the rams I8 into synchronism under normal operating conditions.

In certain instances wherein the press platen is not of too great a weight, it may be maintained level by mechanical means prior to the time it engages the work. This may be done by making the flexible cable sumciently strong to support the weight of the platen and making the journals or pulleys on the platen in the head of sufficient size and strength also to support the weight of the platen. The connection of the cable to the flow dividing valve is then made as is shown in Figure 2. In this flgure there is a block it which is securedto the cable ends and which carries a pin I8 extending into the bifurcated lower end of the lever I0. Rigidly mounted on the press head are a pair of stop members or abutments es of the same width as the block it and bearing against either side of the blocks are the plates t2 which are apertured to permit the passage therethrough of the cable member.

Spaced from the plates 82 are the blocks 8% which are rigidly secured to the press head as by the screws as and between which and the blocks 82 there bear the heavy compression sprin s 88.

It willbe apparent that the arrangement is that of a self-centering device and that the block it will normally be retained in its Figure 2 posi= tion and that movement thereof in' either direction will be resisted by the full thrust of one of the springs 88. As mentioned before, this arrangement will operate to maintain the platen level up until the time it strikes the work, provided the cable and pulleys therefrom and the springs 88 are made sufliciently strong.

There is shown in Figure 3 a somewhat modifled arrangement wherein each of the two rams for actuating the platen has its own individual pump.

The construction of the two rams and the actuating circuits therefor are identical and accordingly a description of only one thereof will be given and the one on the other side of the press will be correspondingly numbered with the addition of an A.

Referring to Figure 3, the actuating rams are indicated at 90 and 90A. Connected between the advancing and retracting means of the ram 90 is a pump 92 having a servomotor mechanism 94 shiitable for selectively reversing the pump delivery. A linkage 96 is connected to the servomotor 94 with a rod 98 which is arranged like the rod 62 in Figure 1 with an actuating solenoid I00. A link I02 is included in the linkage 96 and is operable, when extended, to move the pump 92 toward retraction stroke position. Thus, if the pump 92 is delivering to the advancing means of the ram 90 and the link I02 is extended, the delivery of the pump 92 will be reduced and the ram 90 will.

slow down.

The link I02 is best seen at Figure 4 wherein it comprises a casing I04 having therein a movable member I06 normally urged in one direction by a spring I08 and adapted for being moved in the other direction by energization of a solenoid 0. One end of the casing I04 is connected with the linkage 96 and the opposite end of the member I05 is also connected with the said linkage. It will be apparent that energization of the coil I08 will operate to increase the effective length of the link I02.

A simplified electrical control circuit for the arrangement of Figure 3 is shown in Figure 5. In this figure there are the power lines LI and L2 and therebetween there is connected a contactor coil A in series with the normally opened start button H2 and the normally closed stop button III. The start button H2 is toy-passed by the normally opened blades A-I of the contactor coil A which provides a holding coil for the contactor coil after the latter has been energized by closing the push button II2.

Connected in parallel with coil A are the solenoids I and I00-A energizable for shifting their associated

pumps

92 and 92--A into forward delivery position.

The coil IIO of the extensible link I02 is connected between the lines L--I and L2 and in series with a normally opened limit switch LS-I while the coil I I0A of the extensible link I02A is connected in series with the normally opened limit switch 1.8-2.

The limit switches are positioned as shown in Figure 3 on either side of a member II 3 which is secured to the cable H5. As explained in connection with Figure 1 tilting movements of the platen IIS will be accompanied by movement in one direction or the other of the member I I3 with the cable I I5. For example, tilting of the platen IIS downwardly at its right end will result in a movement toward the left of the member I I3 and closure of the limit switch LS-2. This will reduce the delivery of the pump 92-A and thereby slow down the rate of movement of the ram 90A. This will operate to restore the platen to its level condition whereupon the limit switch LS2 will again open and full delivery of the pump 02-A will be resumed.

In Figure 6 there is shown an arrangement somewhat similar to that shown in Figures 1 and 3 and wherein each of two rams has its own source of pressure fluid. but wherein the control of the tilting of the platen is accomplished by pressure responsive means.

Referring to only the left hand side of the arrangement shown in Figure 6, and'applying the same numerals to the right hand side with the addition of an A, there is a ram I20 which has its advancing and retracting means connected with the service ports of a reversing valve I 22. The valve I22 receives pressure fluid from a conduit I26 which leads to one port of a valve i526 which also has another port therein connected by the conduit I28 to receive pressure fluid from the pump I38. The valve 526 has therein a valve member i 32 which is normally urged by the spring ltd into position to provide free communication between the conduits I20 and E28. Movement of the valve member H32 in the opposite direction will set up a restriction to flow between the said conduits.

The valve member 832 has thereon a fluid operable area connected by the conduit I36 with the conduit I25 and acting in a direction opposite to the thrust of the spring H30. The conduit i2 5 is also connected by a conduit I323 with the smaller side of a piston I d0 which is'connected with the movable flow control member of the pump I 30 and acting in a direction to increase the deliver of the said pump. The pump is also urged toward increased delivery position by a spring I452 and the opposite side of the piston I 40 is also connected by a conduit I'M with the conduit E28 for urging the pump toward decreased delivery position.

The spring Ififl has its end opposite the valve member I32 engaged by a cup washer which is abutted by the end of a r0 I06 adjustably carried in a fitting I50. The fitting I 56 is connected for actuation by lever I52 which is pivoted at I54 and which has its lower end connected with the cable I50 for movements therey.

ISO-A through the valves I 26 and I2B-A with the said advancing means will obtain until the platen tilts from a level position. Upon any delivering movement of the platen I58 the lever I52 will be shifted about its pivot I54 to increase the tension on one of the springs of the,

valves I20 and I26A and to decrease the tension on the other. Assuming that the platen has delivered downwardly on its right side as viewed in Figure 6, the tension on the spring I34 will be increased and that of the spring I 34-A will be decreased. This will cause the valve member I 32--A to yield under a lower pressure and thus to set up a restriction to flow from the conduit I 28-A to the conduit I24A. On the other hand, the valve member I32 will only yield at a higher pressure and therefore less restricted communication is had between the conduits I25 and I24. Normally, the valves I26 and I2t--A will be adjusted whereby the valve members Hi2 and I32--A will fioat in a semirestricting position and any tilting of the platen will be accompanied by an immediate increase in pressure on the lagging ram and a decrease in pressure on the leading ram.

In Figure 7, there is shown arrangement whereb a press platen having four actuating rams could be controlled according to this invention.

In Figure '7 a first cable 200 is connected to pass diagonally across or through the platen 202 and is connected with the control means 20% for the rams 205 positioned at the said diagonally opposite corners. The rams 208 on the other diagonally opposite corners are similarly controlled by a cable 2! 0 which crosses the platen diagonally and in alignment with the said rams. By the arrangement shown in Figure 7 the platen is maintained substantially level because each corner of the platen is controlled by the one diagonally opposite; Thus, the platen cannot tilt in any direction without disturbing the balance of the control system for the several rams.

In Figure 8 there is shown an arrangement wherein there are a plurality of rams arranged in a line to actuate a platen such as a bending brake, a shear, or the like. In accordance with the principles set forth in connection with Figure 7, the two rams 282 are connected together through a flow dividing valve 25 which is controlled by the cable Zit which passes across or through the platen Zit between the rams 292. Similarly, the two rams 220 are connected .together by the flow dividing valve 222 which is controlled by a cable 22% arranged relative to the ram 220 like the cable 266 is relative to the ram 2 i2.

As in the case of the arrangement shown in Figure 7 the platen 2th is maintained level at all times and tilting or bending in any direction will result in immediately setting up restoring forces thereon.

Figure 9 shows a simplified arrangement wherein there is a single cable 300 which is anchored at 302 on the bed 304 and which-extends upwardly and around the

pulleys

306 and 308 on the platen 3I0. From the pulley 303 the cable 300 passes upwardly and around the pulley 3K2 on the press head 3M. The end of the cable which is actuated by the lever 320 which. is

pivoted onthe head 3 and connected with the cable 300.

The arrangement shown in Figure 9 is quite simple and is adequate in any instance wherein it is not desired to support the platen weight by the cable, or wherein it is not desired to provide for a pre-stressed cable as in the other modifications illustrated.

It will be understood that this invention is susceptible to modification in orderto adapt'it to different usages and conditions and, accordingly, it is desired to comprehend such modifications within'this invention as may fall within the scope of the appended claims.

I claim:

1. In a press having a press head, a press bed, and a press platen reciprocable therebetwecn; a plurality of fluid operable means for reciprocating said platen; a fluid source for supplying pressure fluid to said means; flow controlling means for determining the relative amounts of fluid supplied to said means; a substantially inextensible and flexible member connected between said head and bed and extending transversely across said platen; and means connecting said member with said flow controlling means for operation thereof by deflections of said platen from a level position.

2. In a hydraulic press; end members constituting a press head and a press bed, and a press platenv reciprocable therebetween; a plurality of fluid operable means for reciprocating said platen; means of supplying actuating fluid to said fluid operable means; flow controlling means operable for determining the relative quantities of fluid supplied to said fluid operable means; and means for actuat ng said flow controlling means in response to tilting movements of said platen comprising a flexible and substantially inextensible member anchored on one of said end members. extending therefrom to said platen, across said platen and thence to the other of said end members; and means connecting the end of said flexible member at said other end member to said flow controlling means.

.3. In a press; end parts constituting a head and a bed, and a platen reciprocable therebetween; a plurality of fluid operable motor means connected with said platen for driving it in its reciprocating movements; a flexible cable extending transversely across said platen and from one end thereof toward one of said end parts and from the other end thereof toward the other of saidend parts; means anchoring one end of said cable on one of said end parts; the other end of said cable being movable relative to the other end part; a fluid source for supplying fluid to said fluid operable means, flow dividing means between said source and said fluid operable means to determine the division of fluid therebetween; and means connecting the said other end of said flexible member with said flow dividing means.

4. In a hydraulic press having a head, a bed, and a platen reciprocable therebetween; a plurality of spaced fluid operable motors for driving said platen in its reciprocating movements; means for. supplying actuating fluid to said motors; flow controlling means for determining the relative amounts of fluid to be supplied to said motors; and means of actuating said flow contil trolling means in response to tilting movements of said platen comprising cable means anchored on said bed, extending to said platen, transversely across said platen, and thence to said head to be connected with said flow controlling means.

5. In combination with a press comprising rigidly interconnected end parts and a platen reciprocable therebetween, and having a plurality of fluid operable motors for actuating said platen; fluid flow controlling means for determining the supply of fluid to said motors and operable to vary the relative quantities supplied to the separate motors; and means of actuating said flow controlling means comprising cable means connected therewith, extending transversely across one of said end parts, then to opposite ends of said platen, then across said platen in opposite directions, and then to the other oi said end parts and rigidly anchored thereon.

6. In a press having a head, a bed and a platen; cable means having its opposite ends anchored on said bed and extending therefrom to said platen, then across said platen in opposite directions, then to said head, and then across said head; means normally urging said cable toward a predetermined fixed position whereby said platen is normally maintained level; fluid motors acting on said platen at spaced points; control means for regulating the fluid supply to said m0- tors; and means responsive to movements of said cable relative to said head brought about by the tilting of sa d platen for actuating said control means to regulate the fluid supply to said motors to set up unbalanced forces on said platen tending to restore the same to a level position.

7. In a press having a spaced apart head and bed and a platen reciprocable therebetween: cable means having its opposite ends anchored on said bed and extending therefrom to said platen in a direction parallel to the movement of said platen, across said platen in opposite directions, then to said head also in a direction parallel with the movement of said platen, and then across said head; centering springs on said head engaging said cable and normally urging it into a predetermined condition for normally maintaining said platen level; motor means acting on said platen at spaced points; control means for controlling the energization of said motor means; and means responsive to relative movements of said cable and head as brought about by tilting movements of said platen for actuating said control means to vary the energization of said motor means to set up unbalanced forces on said platen tending to return it to a level position.

8. In a press having a head and a bed spaced apart vertically and a platen reciprocable therebetween; cable means anchored at opposite ends of said bed and extending vertically therefrom to said platen, then across said platen in opposite directions, then vertically to said head, and then across said head; centering spring mean continuously urging said cable into a predetermined position relative to said head; and fluid operable means responsive to relative movement between said head and cable for setting up unbalanced forces on said platen.

9. In a press having end members constituting a head and a bed and a press platen movable between said end members; a plurality of fluid operable motors connected with said platen for reciprocating the same; a pump connected with each said motor for supplying actuating fluid thereto; delivery controlling means for each of said pumps operable for varying the delivery thereof; and means for operating said delivery control means to vary the delivery of said pumps to said motors for maintaining said platen parallel to a predetermined plane at all times and comprising cable means extending transversely across said platen and then to said end members in a direction parallel with the direction of movement of said platen; means anchoring said cable means on one of said end members; and means connecting said cable means remote from the point of anchoring thereof with said delivery controlling means.

10. In a hydraulic press; a head, a bed and a platen; a plurality of fluid motors connected for actuating said platen; cable means anchored at opposite ends of said bed and extending therefrom to said platen in a direction parallel with the direction of movement of said platen; journal means at opposite ends of said platen, said cable means passing over said journal means, transversely across said platen, and toward said head in the same said direction; journal means at opposite sides of said head, said cable means passing over said journal means and extending transversely across said head; and means connected for operation by said cable means in response to movements thereof relative to said head for determining the relative quantities of fluid to be supplied to said motors.

11. In a hydraulic press; a press head, a press bed, and a press platen reciprocable between said head and bed; spaced fluid operable motors for actuating said platen; pressure fluid supply means for supplying actuating fluid to said motors; flow controlling means operable to determine the relative quantities of fluid to be supplied to said motors; yielding means continuously urging said flow controlling means toward one extreme position; and cable means also connected with said flow controlling means for the operation thereof upon deflections of said platen from a level position, said cable means extending therefrom to said platen; then across said platen t the opposite end thereof, and then to said bed to be anchored thereon.

12. In a press having end parts constituting a head and a bed, a platen reciprocable therebetween, a plurality of spaced fluid motors for actuating said platen, and fluid supply means for supplying actuating fluid to said motors; platen leveling means comprising flexible inextensible means extending from one side Of one of said end parts to the other side of the other of said end parts and passing transversely across said platen; journal means at oppoiste sides of said platen for supporting said flexible means; means rigidly anchoring said flexible means on one of said end parts; and means responsive to relative movements between said flexible meansaand the other of said end parts for varying the relative amounts of fluid supply from said supplying means to said motors for urging said platen 'in a direction to counteract said relative movement.

13. In a press having a head, a bed, a platen reciprocable therebetween, a plurality of spaced fluid motors for actuating said platen, and fluid pressure supply means to: mp y s actuating fluid to said motors; means for maintaining said platen parallel to a predetermined reference plane throughout its reciprocating movements and comprising flexible inextensible means extending from each side of said head to the opposite sides of said bed and passing transversely across said platen; journal means at opposite sides of said platen for supporting said flexible means; means rigidly anchoring said flexible means at each side of said bed; journal means at each side of said head, said flexible means passing thereover and across said head and being interconnected; spring means urging said flexible meansinto a predetermined position relative to said head and being sufficiently strong to maintain said platen level before it engages the work; and other means responsive to movements of said flexible means relative to said head for varying the relative quantities of fluid supply to said motor means for maintaining said platen level under load.

14. In a press with a head, a bed, a platen reciprocable therebetween, a plurality of spaced fluid motors for actuating said platen, and fluid pressure supply means for supplying fluid to said motors; means comprising flexible inextensible means connected between said head and bed, extending transversely across said platen, and operating as a parallel motion mechanism; said flexible means extending across said head and being connected and being anchored on said bed; and means responsive to relative movements between said flexible member and head brought about by tilting movements of said platen for varying the relative pressures at which fluid is supplied to said motors.

15. In a press having a head, a bed, a platen,

a plurality of actuating motors for said platen, and fluid supply means for said motors; leveling means for said platen comprising flexible inextensible means extending from said head to said bed, passing transversely across said platen, and acting as a parallel motion mechanism; said flexible means extending across said head and being connected; adjustable anchor means rigidly securing said means to said bed; valve means connected between each of said motors and said fluid supply means and operable to control the pressure supplied to said motors; and means responsive to movements of said flexible means across said head as brought about by tilting movements of said platen for operating said valve means to vary the pressures acting on said motors.

HOWARD M. PURCELL.

Name Date Coyle Apr. 26, 1910 Monier June 6, 1944 FOREIGN PATENTS Country Date Germany Oct. 15, 1929 Number Number