US2696183A - Press - Google Patents

Description

J. A. CHYBA Dehc. 7, 1954 PRESS 5 Sheets-Sheet 1 Filed Oct. 1. 1949 BYwnAmYmf/W ATTORNEYS Dec. 7, 1954 J. A. CHYBA 2,696,183

PRESS Filed 0st. 1. 1949 5 Sheets-Sheet 2 mi i l im

5 I a ii Il' l il lgz' INVENToR.

.fasi/H11 cum BY v A TTOR/VE YS Dec.l 7, 1954 J. A. CHYBA 2,696,183

PRESS Filed oct. 1. 1949 5 sheets-sheet s 'igg IN VEN TOR.

JSEPH CHYB BYwwMmyw/W,

A TTORNE'YS J. A. CHYBA Dec. 7, 1954 PRESS v5 Sheets-Sheet 4 Filed Oct. l. 1949 BEV. xmwm TTORNEYS J. A. CHYBA Dec. 7, 1954 PRESS 5 Sheets-Sheet 5 Filed Oct. l, 1949 JOSEPH /LCHYB TTOHNEYS PRESS Joseph A. Chyba, Baltimore, Md., assigner to Hydro- Form Corporation, Baltimore, Md., a corporation of Maryland Appiication October 1, 1949, Serial No. 119,066 14 Claims. (Cl. 113-44) This invention relates to improvements in presses and has particular reference to an improved construction of press particularly adapted for metal shaping or forming operations.

One of the objects of the present invention is the provision of a simple self-contained mobile press capable of development of high operating pressures.

A further object of the invention is the provision in a structure of this character of simplified control means for mechanically locking the respective movable elements of the machine in closed' position during the forming operation.

A further object of the invention is the provision of an improved actuating circuit and controls therefor for a press mechanism, so related and arranged as to minimize the possibility of inadvertent operation of the power actuated press elements, and thus the possibility of injury to the press operator.

States Patent O Other objects and advantages of the present invention should be readily apparent by reference to the -following specification, considered in conjunction with the accompartying drawings forming a part thereof, and it is to be understood that any modifications may be made in the exact structural details there shown and described, within the scope of the appended claims, without departing from or exceeding the spirit of the invention.

Referring to the drawings in which similar reference characters are employed to denote the same or similar parts:

Figure l is a perspective view of a press embodying the features of the present invention.

Figure 2 is an enlarged fragmentary perspective view particularly illustrating the locking members for the movable press head and associated parts.

Figure 3 is a vertical sectional view illustrating the various elements of the forming mechanism as on the line 3 3 of Figure 4.

Figure 4 is a horizontal sectional view on the line 4-4 of Figure 3.

Figure 5 is a fragmentary sectional view on the line 5--5 of Figure 4.

Figure 6 is a diagrammatic view illustrating the actuating circuit including the various controls therefor and parts actuated thereby.

1n the drawings the numeral 10 designates the frame of the press unit supported by rollers 11 and provided-with the door sections 12, 13 and `14 permitting access to the interior of the press wherein is contained the reservoir 15 in the event that hydraulic actuating medium for the press is employed. Likewise contained within the body portion 1U is the drive motor 16, pressure pump 17, with by-pass relief valve 18 and the various pipe or conduits and control valve elements particularly illustrated in Figure 6. This piping, it will be noted, includes thepressure gage 19 having the enlarged dial 20 on the face of the machine disposed in cooperative relationship with the dial 21 indicating the position of the forming or die carrying plunger 22. The particular cooperative action of these parts form no part of the invention here claimed inasmuch as they constitute the subject matter of my cepending application, Serial No. 12,871, now Patent No, 2,556,672, issued May l, 1951.

The frame unit 10 is provided with the low bed portion having mounted thereon the supports 24 for the lower press vunit or block 25. Extending downwardly through. the block. and supports 24, and secured to the bed portion 23 :are the tie rods or columns 26 on which is slidably guided the press head 27. The upper ends of the coiumns 26 project through the cap plate 28 which is secured in position at the top of the columns by the nuts 29. The columns, shown as four in number, yprovide 2,696,183 Patented Dec. 7, 1954 ICC guides for the vertical movement of head 27 in properly guided relation with respect to the member 25.

To effect the desired vertical movement of head 27 there is mounted on the plate 29 a cylinder 30 containing piston 31 from which depends the piston rod 32 attached as by threaded connection 33 to the circular nut and guide element 34 secured by the plurality of bolts 35 to the head 27. As this piston is ordinarily only to perform the work of raising and lowering the head 27, `t can be made relatively small in size and only a light veight cylinder is required. Hydraulic actuating medium Ior effecting the downward movement is introduced by way of conduit 36 and piston head 37 while the hydraulic medium for raising the piston, and thus the head is introduced through conduit 38 by way of the cylinder head 39.

Movement of the piston is controlled by the reversing valve 4t) mounted in the frame 10 having a valve plunger 41 which in its central or intermediate position, as shown in Figure 6, blocks olf both conduits 36 and 38. The valve plunger 41 has an intermediate groove 42 receiving pressure from pump 17 by way of conduit 43 forming part of the main power circuit. A branch conduit 143 extending from the conduit 43 between valves 40 and 100 provides a discharge from the main power circuit to reservoir through relief valve 144. This valve 144 determines the maximum effective pressure available in 43. When valves 89, 97, or 100 are shifted from the power circuit completing position shown in Figure 6, they each interrupt the series connection of the power circuit through these valves to the reversing valve 40. When either of these valves is so shifted, the effective pressure in the power circuit is that established by the valve 18, which, as is conventional in hydraulic power or control circuits of the type here illustrated, has a higher value than the valve 144. Thus, a higher pressure is rendered available for charging the dome and for actuation of the pistons 72 and 108 than is utilized or required for actuation of piston 31 which serves merely for positioning of one of the press elements. Forward movement of the control handle 44 shown at the left in Figures l and 6 serves to move the plunger portion of the valve so that the groove or cannelure 42 will connect pressure conduit 43 with conduit 36 to lower the head, while at the same time the conduit 38 extending to the underside of the piston Vis connected through the chamber of valve 40 with return conduit 45 extending to reservoir so that the hy.`

draulic medium may be reutilized.

Opposite or inward movement of the control handle 44 will oppositely shift valve 41 coupling the pressure conduit 43 with conduit 38 to effect upward movement of piston 31 while at the same time conduit 36 now becomes a return line coupled through the lower or forward chamber of the valve with the reservoir conduit 45.

The control handle mounting for effecting these movements is of conventional three-position type having the centralizing springs 46 and 47 normally holding the handle in the intermediate position specifically shown in Figure 6, permitting its manual movement either forward or back as desired, but automatically returning the handle to neutral when released.

In Figures l, 2, 3, and 4, the head 27 is shown in its lowered position so that the press is conditioned for suitable forming of the metal blank 48. To retain the head in its lowered position, positively to prevent movement thereof without dependence on hydraulic pressure on piston 31 or the like, one or more of the guide columns 26 have been grooved as at 49 to provide the locking shoulders 50. As most clearly shown in Figure 4, there are pivoted as at the points 51 on the upper face of the head the pairs of locking elements in the form of arcuate jaws 52 and 53 having the intermeshing toothed or gear portions 54. These jaw members are of width to just fit within the grooves 49 and beneath the shoulders 50 when in their closed position as particularly shown in Figures l and 4. They thus bear at the one side against the upper face of the head 27 and at their opposite side or face fit beneath and interlock with the shoulders 50, securely locking the head in position. As shown, one of the members 52 is provided with an actuating handle 5S having a locking pin releasing portion 56 pivoted to a bracket 57 carried by the jaw 52 having on its outer end locking pin 58 which extends downwardly through the jaw 52 for engagement in the pin socket 59. When the parts are in closed or locking position as shown 1n Figure 4, the pin by engagement 1n the socket retains the clamping members in position. To release the head for retracting movement it is only necessary for the operator to grasp and press together the sections 55 and 56 withdrawing the locking pin and to then impart a counterclockwise swinging movement to the jaw 52. This motion will be transmitted through the several in terlocking gear or circular rack portions 54 on the various jaws causing opposite actuation of the jaws of each pair, opening same to the posltlon shown 1n F1gure 2 when the head 27 may be readily raised.

It will be noted that one of the jaws 53 is provided with the safety device actuating arm 60 for engagement with roller 61 on switch arm 62 of the solenoid controlling safety switch 63. This switch may be of conventional construction in which the arm 62 is spring actuated into a forward position. When the jaws are closed, the counterclockwise movement of jaw 53 will correspondingly shift arm 60, pushing roller 61 to the rear to close contact in the switch 63. This, in turn, will energize solenoid 64, moving the safety valve 65 from its blocking position as shown in Figure 6. Such movement couples the pressure conduit`66 with conduit 67 extending by way of check valve 68 and conduit 69 to the pressure dome 70 inside head 27. Coupled into the pressure conduit 69 is the gage member 19 previously referred to which registers the 'pressure at any time existing in chamber 70.

The particular elements for imparting desired deformation 0r shape to the work piece 48 are shown in detail in Figure 3.

It will there be noted that the base block 25 is formed with the large cylinder or chamber 71 in which is vertically movable piston 72 provided with a downward extending piston rod 73 which carries at its upper end the plunger 22 having a socket 75 to receive the tang 76 on which is mounted the plunger die element 77. This plunger is slidable through a central aperture in the bolster plate 78 which forms a top closure for the cylinder 71 and is recessed at 79 to receive the die nest 80 having a central aperture or bore 81 normally receiving and through which moves the die element 77. The upper face of the nest serves as a support for the work piece 48 prior to and during the forming or drawing operation. Forming a closure for the lower side of the pressure dome or chamber is a flexible or elastic diaphragm 82 retained by suitable clamping mechanism 83 including the ring 84 interitting with the periphery of the nest 80. The height of the member 78 and of the nest S0 are such that the diaphragm will be tightly compressed against the upper face of the nest and the work piece imbedded therein when the head is clamped in its lower position, as is clearly shown in Figure 3.

With the parts so located and secured, handle 85 may be forwardly actuated against action of spring 86 to couple pressure conduit 87 by way of groove 88 in valve 89 with the dome pressure conduit 66, creating sufficient pressure in the dome to cause the diaphragm firmly to hold the work piece against the nest and condition the parts for the forming operation. This having been effected, handle 85 is released and will be restored by spring 86 to the position shown in Figure 6 when the lower spool of Valve 89 will blank off return flow through conduit 66. Such iiow. of course. is additionally blocked by the automatic check valve 68 so that any escape or release of pressure within the dome chamber 70 will be by wav of conduit 90 and the variably positionable throttle valve 91. This Valve, as shown in Figure 6, is normally in forward position, blocking the iiow from conduit 90 into conduit 92. It may. however, be rearwardly actuated as respects the position shown in Figure 6 to control the release of pressure as by operation of valve handle 93 normally held in forward position by the action of spring 94.

The desired initial pressure having been created in dome 70 the subsequent shaping operation is performed by supplying pressure in the lower portion of cylinder 71 forcing piston 72, plunger 22 upwardly to urge die 77 against the work piece 48. .The dome pressure reacting on the resilient diaphragm clamps the edge of the material against the surface of the nest surrounding the die 77 so that desired tension may be maintained on the peripheral portion of the work as the material 48 and diaphragm are forced upwardly into the dome, it being understood that this movement will cause an automatlc increase in pressure withinthe dome.

To control the introduction of pressure into the chamber 71 it will be noted that the pressure conduit 95 is normally connected by Way of the groove 88 in valve 89, groove 96 of valve 97, conduit 98, groove 99 of valve 100 to the pressure input conduit 43 communicating with the groove 42 of valve 41. It will be evident that these several valves are serially arranged in such manner that movement of either valve 97 or 99 from its normally spring etected position, as shown in Figure 6, will interrupt any possible iiow of pressure by way of valve 41 for movement of the press head. Likewise, as valve 39 is serially arranged intermediate the source of pressure medium, and the pressure conduit movement of this valve for effecting introduction of pressure into the dome will prevent any possible utilization of pressure tending to disturb the position of the head or the die plunger. Consequently, there has been in this respect provided a safety feature in that valve 65 prevents introduction of pressure into the dome which might tend to distort or blow out the resilient diaphragm, the diaphragm pressure being introducible only when the head is in its lowered position and the clamps in position mechanically to lock the head against movement. Correspondingly, the valve 97 serves as a safety selector so that the actuating pressure may be employed either as respects the cylinder 71 for raising the plunger or as respects up and down movement of the head under control of valve 41, but both movements cannot be simultaneously effected. Additionally, the inward movement of valve 100 to couple pressure for retraction of the plunger and die likewise disconnects the power source from the head so that no movement of the head is possible under these conditions.

An additional four-way valve 101 has been provided under control of the bi-directionally movable valve handle 102. This handle is maintained in a centralized position as shown in Figure 6 by the springs 103 and has a central spool 104 normally blocking the branch 105 of the plunger retraction conduit 106 which extends to the small cylinder 107 containing piston 108 on the lower end of piston rod 73. This spool 104 at the same time blocks branch conduit 109 of the conduit 110 extending to the lower portion of cylinder 71. Forward movement of lever 102 serves to couple 109 with reservoir conduit 111 while rearward movement maintains 109 blocked but couples conduit with 111 for movement of the opposed pistons 72 and 108. In this manner, a blocking or throttle control is provided in the reservoir connections from the oppositely acting cylinders 107 and 71 so that when either cylinder is connected to pressure the back pressure may be relieved in the other, permitting piston movement. Forward pressure for raising the piston 72 is supplied bv forward movement of valve controlling lever 112 against positioning spring 113, thus suitably shifting valve 97 to couple pressure conduit 95 with conduit 110.

It is7 of course, to be understood that in some instances the valve 101 may be eliminated as an independent member or its functions combined with or motion may be derived from movements of the valve members 97 and 100 in the event that the independent lever safety control and throttling of the exhaust conduits from the respective cylinders 71 and 107 are not deemed necessary. .lt is further to be understood that while reference has been made to employment of hydraulic actuating medium for the several pistons and pressure chambers, such medium normallv being a relatively non-compressible oil, that air or other pressure media may be utilized depending upon the forces required which in the small press here illustrated due to its rigidity of construction may witg safety rise to 15,000 to 20,000 pounds per square 1nc lt will be evident that in utilization of the press. head 27 should be in raised position to permit ready introdustion of the work piece 48, and it is desirable the same be securely held in such manner as to prevent accidental downward movement with attendant possibility of injury to the press operator.

The particular mechanism illustrated for this purpose includes the pair of rotatable rods 114 and 115 which are swiveled as at 116 in the head 27 and extend upwardly through the apertures 117 in thecap plate 28. These apertures are of generally' circular .form with the .radially extending slots 118 to receive Ythe ribs 119011` the rods 1.14 and 115, these 'ribs providing the lower terminal shoulders 120. A sleeve 121 mounted on piston rod 32 intermediate the collars 122 carries -an operating handle 123 andthe lugs 124 between which are pivoted as at 125 the links 126. At their outer ends, these links are .pivoted to the rod shifting arms 127 carried by the rods.

By this construction, oscillation of handle 123, through the linkage described, will impart a rocking motion to the rods 114 and 115. A spring 128 tends to rock the rodsand thus the handle 123 in a clockwise direction to the extent permitted by the stop pin 129, while movement f the lever in the opposite direction is limited as by the stop .pin 130. These pins, if desired, may be lof length to engage the under'face of the cap plate and thus limit upward movement of the head.

When the head is in its extreme raised position, the shoulders 120 will be disposed slightly above the upper face of the cap plate 28. Under these circumstances, the spring 128 will oscillate the rods 114 and 115 to such position that the ribs 119 will be movedout of alignment with the slots 118 and will overlie a solid portion of the cap plate surrounding the apertures 117. Slight reverse downward movement of the head 27 will then cause the shoulders to rest rmly upon the upper face of the cap plate, positively locking the head in raised position. On the other hand, when the head is upwardly actuated to its limit of movement the tension on the supporting rods 114 and 115 will be released when handle 123 can lbe shifted, bringing the ribs into alignment with the slots 118 permitting of reverse downward movement of the head. It will be noted that by making one or more of the ribs equal in length to the stroke of the head, that the rods will be maintained in their released ,position during the entire downward movement of the head so that there will be no interference with reverse retraction of the head. When fully raised, release .of engagement of the controlling rib or ribs in the slots 118 permits the 'spring automatically tomove the parts into positive locking position, when frictional engagement -of the shoulders with the plates due to the suspended weight of the head will be adequate to prevent releasing movement of handle 123.

In the operation of the press, with the head 27 locked in its raised position, a work piece or blank, such .as 43, is placed on the nest .in overlying relationship to vthe plunger die 77. Handle 44 is then moved inwardly coupling conduit 38 with pressure, raising head `2'! suiiic'iently to disengage the locking shoulders 120 -with respect to cap plate 28. This operation is yordinarily performed with the right hand of the operator. With lever 44 held in this position, the operator can then grasp lever '123 with his left hand, assuring that the hands of the operator are therefore outside of the press area and lever 12.3 held in its left hand position, aligning the rib or ribs 119 with slots 11S. Reverse or forward rocking of handle 44 will then introduce pressure into conduit 36, ymoving piston 31 and the head 27 downward into the position, particularly illustrated in Figure 3, -the lever 44 bein-g held forward to insure tight clamping together of the parts while the left hand of the operator is shifted to thelhandles 55-56 which are moved in a'clockwise direction to'close the clamps 52 and S3 until locking pin 58 can be suitably engaged in socket 59,l securing the clamps in proper head retaining relationship to the guide columns 26.

At this point, the forming assembly will be lsecurely bound together as a unit in position to be reacted upon by the desired high forming pressures here utilizable.

ln the forming operation it is preferred to first move valveV handle or lever 85 forwardly to admit desired initial pressure through conduit 69 to the dome chamber 70, providing the proper reacting pressure firmly to hold the work blank 48 against nest 80. In .proceeding with the work forming operation, ,valve handle or lever 112-is moved forwardly, blocking of any potential flow of pressure through conduit 98 and-at the 'same time couplin'.Y pressure from 95 to 110, effecting upward movement of piston 72 and the parts associated therewith as particularly illustrated in Figure 3.

It will be understood by those conversant with the art that the upward movement of die 77 tendingto force-the central portion of blank 48 against diaphragm 8?. wiil cause a building up of existing pressure in chamber 70.

The extent and rate of movement ofdie member 77 and thus the formation of shape in the blank 43 can be generally controlled `as respects input of pressure by the extent of movement of valve 97 in connection with the variable throttling of exhaust eifectable by the positioning of spool 104 on valve 101 as determinable by setting or adjustment of lever 103.

ln performance of such operations it is frequently desirable to vary the rate of movement of the die plunger, or to stop the movement for a partial setting of the material to a particular configuration, while in other instances it is desirable that the movement of the die be substantially continuous.

In either event, it is, however, desirable to control the reaction pressure through the diaphragm on the work piece to permit greater or less freedom of movement of the ciamped edge portions over the face of the nest and the extent of forming pressure of the diaphragm to effect conformity of the blank to the shape of the die. To attain this result the operator variably moves handle 93 which controls the position of throttle valve 91 effective as respects the reservoir or return conduit from the dome chamber 70 so that this pressure may be impounded or varied in accordance with particular working conditions.

When the die has reached its desired limit of movement into chamber 70 as determinable by reference to dial 21, release by the operator of valve handle 112 will automatically stop further movement of the die, when the pressure may be maintained for any desired period or immediately released, it being preferable in the operation of the machine that the dome pressure be released before retraction of the other parts of the press. This having been effected, valve lever 130 may be forwardly moved coupling pressure Afrom conduit 98 to conduit 106 operating the stripping piston 108 rapidly to retract the die element, and valvelever 44 is then forwardly actuated introducing pressure against cylinder 31, forcing head 27 downward and releasing the lateral pressure on clamp members 52 and 53.

These clamps can then be opened, releasing the head. Reverse movement of lever 44 will cause pressure to react on the underside of piston 31 raising the head to its extreme upper position, where the spring 128 will eect suiiicient rotation of rods 114 and 115 so that the shoulders will overlie solid portions of the cap plate 28, thus locking head 27 in raised position.

it will be noted that the present construction provides a machine which is small, compact, readily movable and due to its particular construction capable of utilizing highly concentrated working pressures with safety and without strain on parts of the frame to an unusual extent. it will further be noted that due to the particular structure and relationship of controls as shown this invention makes possible theutilization of a wide range of pressures, applied evenly to all surfaces of the work and without harm due to tool marks or the like as respects the iinal surface of the formed part. It will addition-ally be noted that, by the interlocking and serial relationship of the various control valve and other operating mechanisms, in the case of all .important movements of the machine and particularly those which might involve danger to the handset the operator, it is necessary that both hands be occupied-in operation of the machine controls and therefore possibility of in iury to the operator is minimized.

What is claimed is:

l. A forming press including apair of press elements, a first hydraulic piston and cylinder mechanism connected to one of said elements for moving said element from an open work receiving position to a closed forming position, one'of said elements having a pressure chamber and a diaphragm sealing the pressure chamber, a reciprocable die element carried .by the other of saidelements, a second. piston and cylinder mechanism including a pair of opposed piston reacting pressure areas for eifecting opposite reciprocations of said reciprocable die element, and a control circuit for determining the activation of said chamber-and said piston and cylinder mechanisms including a source of actuating medium, and conduits providing a Power circuit connected to the source and extending to the iirst piston and cylinder mechanism, said power circuit having a plurality of valves in the power circuit connected in series by the conduits, said valves including a first selector valve, a branch conduit from said valve to said pressure chamber, `said valve being positionable to interrupt the power circuit and couple the actuating medium with the pressure chamber, a second selector valve in series in the power circuit with said first valve, a branch conduit from said second valve to one of the piston areas of the second piston and cylinder mechanism, said second Valve having a position effective to interrupt the power circuit and to couple the medium to one piston area of said second piston and cylinder mechanism, `a third selector valve serially interposed in the power circuit, a branch conduit from said third valve to the other of the pair of opposed piston areas, said third valve having a position effective to interrupt the power circuit and to couple the medium to the other piston area of said second piston and cylinder mechanism, whereby the positioning of the respective selector valves determines the flow of pressure medium through the power circuit or its diversion into a selected branch conduit.

2. A forming press including a pair of press elements, a first hydraulic piston and cylinder mechanism connected to one of said elements for moving said element from an open work receiving position to a closed forming position, a reversing valve, conduits connecting the reversing valve to said piston and cylinder mechanism to control said movement, one of said elements having a pressure chamber and a diaphragm sealing the pressure chamber, a reciprocable die element carried by the other of said elements, a second piston and cylinder mechanism including a pair of opposed piston reacting pressure areas for eifecting opposite reciprocations of said reciprocable die element, and a control circuit for determining the activation of said chamber and said piston and cylinder mechanisms including a source of actuating medium, and conduits providing a power circuit connected to the source and extending to the reversing valve, and a plurality of valves in the power circuit connected in series by the conduits, said valves including a first selector valve serially interposed in said power circuit, a branch conduit from said valve to said pressure chamber, said valve being positionable to interrupt the power circuit and couple the actuating medium with the pressure chamber, a second selector valve in series in the power circuit with said first valve. a branch conduit from said second valve to one of the piston areas of the second piston and cylinder mechanism, said second valve having a position effective to interrupt the power circuit and to couple the medium to one piston area of said second piston and cylinder mechanism, a third selector valve serially interposed in the power circuit, a branch conduit from said third valve to the other of the pair of opposed piston arcas, said third valve having a position effective to interrupt the power circuit and to couple the medium to the other piston area of. said second piston and cylinder mechanism, whereby the positioning of the respective selector valves and the reversing valve determines the liow of pressure medium through the power circuit or its diversion into a selected branch conduit.

3. A forming press including a pair of press elements, a first hydraulic piston and cylinder mechanism connected to one of said elements for moving said element from an open work receiving position to a closed forming position, one of said elements having a pressure chamber and a diaphragm sealing the pressure chamber, a reciprocable die element carried by the other of said elements, a second piston and cylinder mechanism including a pair of opposed piston reacting pressure areas for effecting opposite reciprocations of said reciprocable die elemerit, and a control circuit for determining the activation of said chamber and said piston and cylinder mechanisms including a source of actuating medium, and conduits providing a power circuit connected to the source and extending to the first piston and cylinder mechanism, said power circuit having a plurality of valves in the power circuit connected in series by the conduits, said valves including a iirst selector valve, a branch conduit from said valve to said pressure chamber, said valve being positionable to interrupt the power circuit and couple the actuating medium with the pressure chamber, a second selector valve in series in the power circuit with said first valve, a branch conduit from said second valve to one of the piston areas of the second piston and cylinder mechanism, said second valve having a position effective to interrupt the power circuit and to couple the medium to one piston area of said second piston and cylinder mechanism, a third selector valve serially interposed in the power circuit, a branch conduit from said third valve to the other of the pair of opposed piston areas,

said third valve having a position effective to interrupt the power circuit and to couple the medium to the other piston area of said second piston and cylinder mechanism, whereby the positioning of the respective selector valves determines the ow of pressure medium through the power circuit or its diversion into a selected branch conduit, return flow conduits individual to the respective piston reacting pressure areas for controlling the movements of the second piston and cylinder mechanism, a return ow control selector valve coupled to said return flow conduits, said valve having a first position blocking the return flow as respects both of said conduits, and other positions to couple one or the other of said conduits to reservoir, whereby the direction and extent of operation of the second piston and cylinder mechanism is jointly controlled by said return flow control selector Valve and the positioning of one of the selector valves in the power circuit.

4. A forming press including a pair of press elements, a first hydraulic piston and cylinder mechanism connected to one of said elements for moving said element from an open work receiving position to a closed forming position, a reversing valve, conduits connecting the reversing valve to said piston and cylinder mechanism to control said movement, one of said elements having a pressure chamber and a diaphragm sealing the pressure chamber, a reciprocable die element carried by the other of said elements, a second piston and cylinder mechanism including a pair of opposed piston reacting pressure areas for effecting opposite reciprocations of said reciprocable die element, and a control circuit for determining the activation of said chamber and said piston and cylinder l mechanisms including a source of actuating medium, and

conduits providing a power circuit connected to the source and extending to the reversing valve, and a plurality of valves in the power circuit connected in series by the conduits, said valves including a first selector valve serially interposed in said power circuit, a branch conduit from said valve to said pressure chamber, said valve being positionable to interrupt the power circuit and couple the actuating medium with the pressure chamber, a second selector valve in series in the power circuit with said first valve, a branch conduit from said second valve to one of the piston areas of the second piston and cylinder mechanism, said second valve having a position effective to interrupt the power circuit and to couple the medium to one piston area of said second piston and cylinder mechanism, a third selector valve serially interposed in the power circuit, a branch conduit from said third valve to the other of the pair of opposed piston areas, said third valve having a position effective to interrupt the power circuit and to couple the medium to the other piston area of said second piston and cylinder mechanism, whereby the positioning of the respective selector valves and the reversing valve determines the liow of pressure medium through the power circuity or its diversion into a selected branch conduit, return flow conduits individual to the respective piston reacting pressure areas for controlling the movements of the second piston and cylinder mechanism, a return flow control selector valve coupled to said return flow conduits, said valve having a first position blocking the return flow as respects both of said conduits, and other positions to couple one or the other of said conduits to reservoir, whereby the direction and extent of operation of the second piston and cylinder mechanism is jointly controlled by said return flow control selector valve and the positioning of one of the selector valves in the power circuit.

5. In a forming press including a pair of press elements, a first piston and cylinder mechanism including a reversely actuable hydraulic piston connection to one of said elements for moving said element from an open work receiving position to a closed forming position, one of said pair of press elements having a pressure chamber and a diaphragm sealing the pressure chamber, a plunger supported by the other press element for reciprocation relative to its supporting element, and a second piston and cylinder mechanism coupled with said plunger having a first effective piston pressure area reacting to shift the piston and plunger in one direction and a second effective piston pressure area reacting to shift the piston and plunger in the opposite direction, a hydraulic circuit for determining the pressure conditions in said chamber and in said piston and cylinder mechanisms, said circuit including a pressure medium supply conduit,

a first selector valve coupled with the supply conduit, a first conduit extending from the valve to the pressure chamber, a second selector valve, a second conduit connecting said iirst and second selector valves, said first selector valve being alternatively positionable to couple the supply conduit with said rst conduit or with said second or valve connecting conduit, a third selector valve, conduit means connecting said second and third selector valves, additional conduit means connecting said second selector valve with lone of the piston pressure areas of the second piston and cylinder mechanism for transmitting pressure actuating medium to actuate said second piston and cylinder mechanism in one direction, a reversing valve, conduit means connecting the third selector valve with the reversing valve, additional conduit means connecting said third selector valve with the other of the piston pressure areas of the second piston and cylinder mechanism than that to which the conduit from the second selector valve is coupled for transmitting pressure actuating medium to effect actuation of said second piston and cylinder mechanism m an opposite direction to that etfected by connection thereto of pressure medium through the second selector valve, said third selector valve being alternatively positionable to couple the pressure actuating medium either to said conduit connecting it to the reversing valve or to the conduit connecting said third selector valve to said second piston and cylinder mechanism, a pair of conduits extending from the reversing valve to opposite ends of the cylinder portion of the first piston and cylinder mechanism, and additional reservoir connection conduits extending from said reversing valve, said reversing valve being positionable alternatively to couple one or the other of the pair of conduits extending to the first piston and cylinder mechanism with the conduit from the third selector valve to the reversing valve and to couple to a reservoir conduit the conduit of said pair of conduits not coupled to the conduit from the third selector valve, said reversing valve having an intermediate neutral position blocking flow as respects said pair of conduits and being supported for movement in opposite directions from said intermediate position for determining the direction of actuation of said piston and cylinder mechanism.

6. A press construction as claimed in claim l having individual manually operable controls coupled with the several selector valves for effecting positioning movement of said valves.

7. A press construction as claimed in claim 1 having means individual to and reacting on said selector valves for effecting a first definite positioning of the y said selector valves.

8. A press construction as claimed in claim 1 having means individual to and reacting on the selector valves for effecting a first deiinite positioning movement of the said selector valves, and having additional manually operable Shifters connected to said valves for effecting individual movements of the same from their said first definite positions.

9. A press construction as claimed in claim 2 having. a rst means connected to the reversing valve for maintaining the reversing valve in an intermediate neutral position, and additional manually operable means connected to said reversing valve for movement of the valve in one direction or the other from said intermediate position to determine the direction of actuation of the piston and cylinder mechanism controlled thereby.

l 10. A press construction as claimed in claim 3 havmg a first means connected to the reversing valve for maintaining the reversing valve in an intermediate neutral position, and additional manually operable means connected to said reversing valve for movement of the valve 1n one direction or the other from said intermediate positlon to determine the direction of actuation of the piston and cylinder mechanism controlled thereby. 11. A press construction as claimed in claim 3 havmg means coupled with the return ow selector valve for mamtaining said return ow control selector valve in an intermediate flow blocking position, and additional means connected to the valve for movement of the valve selectively to unblock one or the other of the return conduits from the piston and cylinder mechanism.

12. A press construction as claimed in claim 3 having a first means connected to the reversing valve for maintaining the reversing valve in an intermediate neutral position, additional manually operable means connected to said reversing valve for movement of the valve in one direction or the other from said intermediate position to determine the direction of actuatlon of the piston and cylinder mechanism controlled thereby, and having means coupled with the return iiow selector valve for maintaining said return ilow control selector valve in an intermediate flow blocking position, and additional means connected to the valve for movement of the valve selectively to unblock one or the other of the return conduits from the piston and cylinder mechanism.

13. A press of the character described including a pair of press members relatively movable from an open Work receiving to a closed forming position, a piston and cylinder mechanism to eect this movement of one of the members with respect to the other, one of said members having a pressure chamber formed therein and a diaphragm sealing the pressure chamber, a source of actuating medium, a conduit connected to the chamber, a conduit connected by Way of a conduit system and reversing valve to the piston and cylinder mechanism, a selector valve structure connected to said conduits and to the source to determine the operative connection of the source through the valve to one or the other of said conduits, said valve having a portion movable to connect the source to the chamber connected conduit or to the piston and cylinder conduit, a locking device movable to secure the relatively movable press members in closed forming position, a blocking valve in the conduit connected to the chamber and movable to unblock the conduit to permit ow of actuating medium therethrough, and means actuable by movement of the locking device for effecting the aforesaid movement of the valve into unblocking position.

14. A press of the character described including a pair of press members relatively movable from an open work receiving to a closed forming position, a piston and cylinder mechanism to eifect this movement of one of the members with respect to the other, one of said members having a pressure chamber formed therein and a diaphragm sealing the pressure chamber, a source of actuating medium, a conduit connected to the charnber, a conduit connected by way of a conduit system and reversing valve to the piston and cylinder mechanism, a selector valve structure connected to said conduits and to the source to determine the operative connection of the source through the valve to one or the other of said conduits, said valve having a portion movable to connect the source to the chamber connected conduit or to the piston and cylinder conduit, a locking device movable to secure the relatively movable press members in closed forming position, a blocking valve in the conduit connected to the chamber and movable to unblock the conduit to permit flow of actuating medium therethrough, and means actuable by movement of the locking device for effecting the aforesaid movement of the valve into unblocking position, said means including a switch having a portion projecting into the path of movement of the locking device and actuable by movement of the locking device and a solenoid controlled by said switch for effecting the shifting of the blocking valve.

References Cited in the tile of this patent UNITED STATES PATENTS Number Name Date 1,865,806 Victor July 5, 1932 1,866,559 Glasner July 12, 1932 1,866,595 Glasner July 12, 1932 1,970,134 Ferris Aug. 14, 1934 2,146,535 Ernst Feb. 7, 1939 2,240,630 Stacy May 6, 1941 2,317,869 Walton Apr. 27, 1943 2,335,917 Cuthbert Dec. 7, 1943 2,343,177 Flowers Feb. 29, 1944 2,350,884 Ernst June 6, 1944 2,357,019 Nowak Aug. 29, 1944 2,460,612 Verson Feb. 1, 1949 OTHER REFERENCES H. P: M. All-Hydraulic Presses for Modern Pressure Processing, Hydrauhc Mfg. Co., Mount Gilead, Ohio, 1945, pages 64 and 81.

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