US3115858A - Hydraulic press - Google Patents

Hydraulic press Download PDF

Info

Publication number
US3115858A
US3115858A US53444A US5344460A US3115858A US 3115858 A US3115858 A US 3115858A US 53444 A US53444 A US 53444A US 5344460 A US5344460 A US 5344460A US 3115858 A US3115858 A US 3115858A
Authority
US
United States
Prior art keywords
pressure
chamber
plunger
valve
fluid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US53444A
Other languages
English (en)
Inventor
Charles L Mitchell
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Milacron Inc
Original Assignee
Cincinnati Milling Machine Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Cincinnati Milling Machine Co filed Critical Cincinnati Milling Machine Co
Priority to US53444A priority Critical patent/US3115858A/en
Priority to GB16976/61A priority patent/GB901278A/en
Priority to DEC28488A priority patent/DE1279607B/de
Priority to DEC24161A priority patent/DE1196154B/de
Priority to FR863648A priority patent/FR1290717A/fr
Application granted granted Critical
Publication of US3115858A publication Critical patent/US3115858A/en
Priority to NL6905724A priority patent/NL6905724A/xx
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
    • B21D22/10—Stamping using yieldable or resilient pads
    • B21D22/12—Stamping using yieldable or resilient pads using enclosed flexible chambers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B5/00—Presses characterised by the use of pressing means other than those mentioned in the preceding groups
    • B30B5/02—Presses characterised by the use of pressing means other than those mentioned in the preceding groups wherein the pressing means is in the form of a flexible element, e.g. diaphragm, urged by fluid pressure

Definitions

  • the present invention relates to a hydraulic forming press of the type having a flexible die member enclosing a fluid pressure chamber.
  • one member of the press as, for example, the head member has a pressure chamber therein containing hydraulic fluid and enclosed by a flexible diaphragm which defines a flexible die member for the press.
  • the head member In operation the head member is lowered to a workpiece blank supported on a bed member and the head member is clamped to the bed member to prevent separation of these members when the pressure in the pressure chamber, acting on the bed member through the diaphragm, creates a reaction on the head member overcoming the lowering torce applied thereto.
  • fluid is added to the pressure chamber from a charging pump and, after a desired initial forming pressure is developed in the pressure chamber, fluid is supplied from a forming pump to raise a male die plunger, mounted in the bed under the workpiece blank, to urge the blank into the flexible die member.
  • the pressure in the pressure chamber acting through the flexible diaphragm, presses the workpiece blank about the male die plunger to form the workpiece in conformity therewith.
  • the size of the pressure chamber diminishes during forming as the male die member is advanced and it is desirable to control the pressure in the pressure chamber, in coordination with the elevation of the die plunger, during forming.
  • a natural pressure cycle is desired, that is, a cycle in which the quantity of oil' in the pressure chamber remains constant after a predetermined initial forming pressure is developed and the pressure thereafter rises solely as a result of diminution of the pressure chamber due to extension of the die plunger.
  • the charging pump is rendered ineffective to supply fluid to the pressure chamber after the initial forming pressure has been reached.
  • fluid from the chamber is released in controlled amounts to the sump during the cycle; if pressures above those resulting from a natural cycle are desired, fluid is supplied to the pressure chamber during the pressure cycle from the charging pump, excess fluid output of the charging pump above that required to yield the desired pressures in the pressure chamber being returned to the sump. In either of these latter two cycles pressure fluid not required in the pressure chamber to yield desired pressures therein is returned to the sump.
  • a variable relief valve is connected to the pres-sure chamber, the output of which leads, not to the sump, but to the hydraulic motor which drives the die plunger.
  • the relief valve is continuously adjusted during the forming cycle by means coordinated with the elevation of the plunger, said means including a cam driven by the plunger, 50 that fluid above the amount required at any stage of the forming cycle to maintain the desired pressure in the chamber is diverted from the chamber to the motor which drives the plunger.
  • the output "ice of the pump will automatically begin raising the plunger the instant the initial forming pressure is reached in the pressure chamber and, if pressures above those resulting from a natural cycle are required, the pump will continue to supply fluid to the pressure chamber during forming and the pump output not required for the pressure chamber will be diverted to the plunger motor throughout the forming cycle. Since it is only the fluid in excess of the requirements of the pressure chamber which is supplied to the plunger motor, there is no possibility, regardless of the pressure desired in the chamber, that the pressure cycle therein will lag behind the movement of the plunger. In other words, the desired coordination between movement or the plunger and pressures in the pressure chamber is assured. If two or more pumps are used, a larger proportion of the pump capacity than would normally be desired can be assigned to the pressure chamber since the excess fluid output therefrom will not be dumped to the sump but will, instead, be available to assist whatever capacity is assigned to the plunger motor.
  • a nest ring mounted on the base of the press has a plunger received therein and is adapted to support a workpiece blank over the plunger.
  • the pressure chamber of the press is defined by an annular casing, or sleeve, having a flexible die member secured in its lower end, the sleeve slidably received over a stationary, depending, cylindrical tub portion of the head of the press which constitutes the lower portion of a hydraulic fluid reservoir.
  • the sleeve is lowered on the head portion, moving the flexible diaphragm from an open position adjacent the head portion to a closed position on the workpiece blank, thereby expanding the pressure chamber behind the flexible diaphragm to draw fluid from the reservoir through a valve in the depending portion of the head member.
  • the sleeve is raised to return the diaphragm to the open position, collapsing the chamber and returning the fluid therein to the reservoir through the valve.
  • the pressure chamber has an expanded size, when the pres-s is closed for forming, determined by the spacing between the nest ring and the tub portion of the head.
  • the size of the expanded pressure chamber can be readily modified, by changing the nest ring and plunger, so that the size of the pressure chamber during forming will be as small as the depth of draw of the particular workpiece conveniently permits. This not only reduces the stroke of the sleeve to shorten the operating cycle, but because of a smaller pressure chamber when the press is closed for forming, less fluid is required in the pressure chamber to produce a desired pressure therein. Thus more fluid is more quickly diverted from the chamber to the hydraulic motor driving the die plunger so that each forming cycle is more quickly effected.
  • the head member When the press is closed, the head member need not be clamped to the nest ring since the reaction of any force exerted through the flexible die member to the nest ring and die plunger is transmitted to the stationary head portion inside the sleeve, and not to the movable sleeve.
  • the sleeve provides a strong pressure chamber casing, Without small radius corners likely to fracture under the high pressures developed in the chamber. Since the pressure chamber is collapsed and the oil evacuated therefrom on each operating cycle, the flexible diaphragm, which must be replaced from time to time, can be quickly replaced when the press is open after completion of any operating cycle without dumping oil from the pressure chamber.
  • FIG. 1 is a cross sectional view showing the press in a closed position
  • FIG. 2 is a view through the lines 22 of FIG. 1;
  • FIG. 3 is a somewhat schematic view, partly in cross section, showing the press in the open position and showing a part of the hydraulic circuit;
  • FIG. 4 is a schematic diagram showing a part of the hydraulic circuit of the machine.
  • FIG. 5 shows the electric circuit for the machine.
  • the hydraulic forming press of the present invention has a frame including base member 10, a head 11, and an intermediate frame member 12.
  • the three frame members are securely held together by four rods 13 extending therethrough.
  • the base has an annular bed supporting member 14 mounted thereon to which is detachably connected by bolts (not shown) the stationary nest ring 15 constituting the bed member adapted to receive the workpiece blank 16.
  • the intermediate frame member 12 comprises an upper annular portion 12a held against the head member 11, and four depending legs 12b (see FIG. 2) spaced around the bed supporting member 14 and seated on the base member 10. The area between the legs permits loading of workpiece blank 16 and removal of a formed workpiece, when the press is open.
  • the head member 11 has a tank 16 mounted thereon and has a sleeve 11a secured to the under side thereof by bolts (not shown) to form a cylindrical depending tub portion (designated generally as 18) of the head member.
  • the stationary tub portion 18 is spaced from the stationary bed member 15 and in registration therewith.
  • the tank 16 is connected through a large passage 17 in the head to the depending cylindrical tub portion 18 of the head to define a reservoir 19 for hydraulic fluid.
  • a valve housing 26 having a large normally closed poppet valve 20 is received in sleeve 11a and connected to the lower edge thereof. Slidably received between the stationary sleeve portion 12a of the frame and the depending stationary head portion 18 is a sleeve, or cylindrical casing, 21.
  • the depending portion 18 includes flexible sealing rings 24 received over sleeve 11a and held in position by valve housing 26 and a jacket 11b received over and secured to sleeve 11a.
  • the rings 24 provide a fluid tight seal between the movable sleeve 21 and the stationary tub portion 18.
  • the sleeve 21 has a flexible diaphragm 22 detachably secured in the end toward the bed by any suitable means as, for example, shown in US. Patent 2,878,767.
  • the sleeve 21, the depending tub portion 18 of the reservoir, the valve 29 and the diaphragm 22 define a chamber 23.
  • each motor 25 comprises a piston 25a received in cylindrical chamber 25b of the head 11, the pistons connected by piston rods 2550 to the casing 21.
  • Each motor has a pair of ports 25:!
  • valve housing 26 secured in the extending tub portion 13 of the reservoir has a valve seat 26a and slidably receives valve stem 21112 which has a nut 20c spaced above the valve housing.
  • a spring 27 interposed between the nut and the valve housing normally holds the valve 20 closed against seat 26a but the force exerted by the spring 27 is set (by adjustment of nut 290) so that the valve is opened by the suction developed in the chamber 23 when the chamber is expanding.
  • the valve housing has a chamber 28 and as the press is opened the valve 20 can again be opened by introduction of pressure to chamber 28 to permit escape of the fluid from the collapsing chamber 23 into reservoir 19.
  • the nest ring 15 has a male die plunger 35 slidably received therein.
  • Plunger 35 which is detachably connected to rod 35a, is advanced and retracted by a hydraulic motor 36 comprising a movable piston 36:! connected to rod 35a and'slidably received in the base member 16.
  • Piston 36a has a chamber 36b slidably receiving therein a stationary piston 36c which is connected by piston rod 36d to the base member 10.
  • the motor36 has on one side a port 36a and when pressure fluid is supplied to this port piston 36a is advanced to raise the plunger 35. On the opposite side the motor has a port 36 communicating with chamber 36b and when pressure is received at this port the piston 36a is retracted to lower the plunger 35.
  • FIGS. 3 and 4 There is shown in FIGS. 3 and 4 the hydraulic circuit for the forming press.
  • a source of hydraulic fluid under pressure 40 which may comprise a single pump, is connected to a pressure line 41 connected to the pressure port 42 of a directional valve 43.
  • a spring centered plunger 44 when in its normal center position as shown in FIG. 4, connects port 42 to port 45 which, in turn, is connected to port 46 through line 59.
  • port 46 When the valve is in the position shown port 46 is connected to return port 47 which is connected to return line 48.
  • Return line 48 discharges into tank 16 so that reservoir 12 is kept full,
  • '61 is energized to shift 5 the excess fluid dumping to a sump 49 through sump line 50.
  • Directional valve 43 is controlled by a solenoid operated pilot valve 51 havin a spring centered plunger 52.
  • Pump 53 supplies fluid at a pressure established by relief valve 54- to a pilot supply line 55 which is connected to pressure port 56 of pilot valve 51.
  • solenoid 13 When solenoid 13 is energized the shiftable valve member 52 is moved to the left and port 56 is connected to port 57 to supply pilot pressure to line and thereby shift valve member 44 of directional valve 43 to the left. This closes off port 46 and pressure builds up in line 5'9.
  • Relief valve 60 connected to line 59 is set to permit a relatively high pressure, say 10,000 p.s.i., in that line.
  • a pressure chamber variable relief valve 7 0 has a shiftable valve member 75 separating two valve chambers, a chamber 71 connected through inlet port 70a to line 69 and a chamber 72 connected to a pilot relief valve 73 through pilot line 74.
  • the areas of the valve member 75 exposed to the chambers 71 and 72 are substantially the same so that when no flow occurs through pilot line 74, and the pressure in chambers 71 and 72, which are connected by line 76 containing restriction 77, are equal, the valve member is held in the left hand position by spring 78.
  • the variable relief valve 70 has an outlet port 79 which communicates with chamber 71 and is closed by valve member 75 when that member is in the left hand position.
  • the plunger 35 has a rack 80 thereon engaged with pinion 81 carried by a shaft 552 journaled in the bed supporting member 14, and the cams 83 and 84 are mechanically connected to shaft $2, as indicated at 85, for rotation in accordance with vertical movement of the plunger 35.
  • the cam 84 holds,
  • Flunger S7 of the pilot relief valve which is separated by spring 8 3 from plunger 86, holds discharge port 89 of the pilot relief valve closed until a predetermined initial forming pressure is developed in pressure chamber 23 of the press. Until the pressure in chamber 23 reaches a predetermined initial forming pressure, there is no flow in pilot line 74 or line 76 and the pressures in chambers 71 and 72 are equal so that outlet port 79 of the variable relief valve "it? is held closed.
  • solenoid SS is energized when the initial forming pressure is reached to shift valve member 93 to the right and connect line 9%) directly to pressure line 41. Since piston 36a is larger than plunger 35, the motor 36, which extends the plunger 35 against the resistance of the closed pressure chamber 23, will offer less resistance to the fluid in line 41 than the chamber 23 so that even with valve plunger 44 held in the left hand position, no additional fluid is supplied to the pressure chamber 25. If the cam 34 is programmed for a natural cycle, port 89 of the pilot relief valve 70 is held closed throughout the cycle so that port 79 is held closed, preventing escape of fluid from the pressure chamber 23.
  • the cam 84 is programmed so that port 89, and hence port 79, are opened to permit fluid to escape from chamber 23 throughout the cycle, the escaping fluid being supplied to motor 36 to aid in the advance of the plunger 35.
  • fluid from chamber 36b of motor 36 is discharged through line 95, port 97 of directional valve 43, port 47 thereof to return line 48.
  • valve 62 is operated by cam 83 to shift the valve member 100 thereof to the rig-ht and relieve the pressure in line 59.
  • solenoid 18 is deerrergized and plungers 52 and 44 of valves 51 and 43, respectively, return to their center positions.
  • solenoid SS is energized to shift valve member 101 of a blocking valve 102 to the right. Operation of valve 102, which is connected to pilot line 74, relieves the pressure in that line and thereby relieves the pressure in line 69 and pressure chamber 23.
  • Solenoid 68 is energized to shift valve member 103 of valve 104 to the right to connect pilot pressure line 55 to pilot line 106, disconnecting line 196 from line 107 leading to the sump.
  • Line 196 is connected to chamber 23 in valve housing 26 and after the pressure in pressure chamber 23 is reduced the poppet valve 20 opens.
  • solenoid 28 is energized to shift valve member 52 to the right, thereby connecting pressure port 56 of the pilot valve to port 108 thereof. Pressure is thus introduced to line 169 connected to port 168 and the valve member 4-4 of the directional valve 43 is shifted to the right, connecting the pressure port 42 thereof With post 97.
  • This connects pressure supply line 41 to line 95 which has a relief valve 116 set as relief valve 60. Prluid from the line 95 is simultaneously directed to the port 315 of the plunger motor '36 and, through line 95a, check valve 112, and line 64, to ports 25a of the casing motors 2 5.
  • Valve lllll comprises a normally open pressure reducing portion 111a and an adjustable restriction 111b, lines on each side of the restriction being connected to the ends of the pressure reducing portion to maintain the pressure drop constant across the restriction 1111).
  • this valve is set to maintain a pressure in line 64 great enough to raise the chamber member 21 when motor ports 25d are connected to the return lines 48 through line 59 and ports 46 and 47 of directional valve 43.
  • Pressure in line 95 shifts piston 113a and plunger 1 131) of valve 113 to the right so that fluid beneath piston 36a is discharged to the sump as the plunger 35 is retracted.
  • a nest ring and plunger 35 are selected, and limit switch ZLS adjusted, so that the size of the expanded chamber 23 will be no larger than required for the particular depth to which the workpieces are to be formed.
  • the switch lLS is operated by dog 11 i mounted on casing 21, and limit switches ZLS, 3L3 and 4L8 are unoperated.
  • the chamber 23 is collapsed and the valve 20 is held closed by spring 27.
  • the plunger 35 is retracted and the cams 253 and '84 are in the positions corresponding to the retracted position of the plunger.
  • Pressure switch IPS is connected to line 6? and will be set to operate at the chamber pressure at which it is desired to operate valve 94, which is operated by energization of solenoid 33 through pressure switch contacts 1PS1. Pressure in the pressure chamber 23 is indicated on gage 115 connected to line 69. With the press closed, as shown in FIG. 1, the plunger 35 is raised to a predetermined height, the switch 4L5 being operated by dog 83a on cam 83 when the workpiece is formed. Since at this time the press is closed and switch lLS released, relay BCR is picked up through normally closed contacts lLS-l and normally open contacts 4LS1, and is sealed in by normally open contacts BCR-3 connected across contacts iLS-l.
  • Solenoid 23 is energized through contacts BCR-6 and 3LS-1 to shift the pilot valve to the right and apply pressure to line 95.
  • fluid is supplied at the ports fidfvand 25e of the plunger and chamber member motors, respectively, and the press is opened, the fluid in chamber 23 being transferred from the collapsing chamber 2 3 to the reservoir 19.
  • switch 11.5 is operated, opening contacts 1LS-l and deenergizing relay BCR.
  • a line 118 leading to chamber 23 is connected through a shut off valve 119 to a source of air under pressure 129 so that air ressure as required can be supplied to the collapsed chamber 23 to facilitate removal of the diaphragm.
  • a hydraulic press having a pressure chamber enclosed by a flexible die member and having a movable die plunger adapted to urge a workpiece blank into the flexible die member as the plunger is extended
  • a hydraulic motor connected to the die plunger having a port to receive fluid under pressure for extension of the plunger
  • a hydraulic pump means to connect the output of said pump to the pressure cham her
  • a variable relief valve having an inlet port and an outlet port and operable to pass fluid above a pressure determined by the setting of the relief valve from the inlet port to the outlet port, said inlet port connected to the pressure chamber and said outlet port connected to said port of the hydraulic motor
  • a cam operatively connected to the die plunger for movement as the die plunger is extended, and means responsive to the position of the cam to set the relief valve for passage of fluid therethrough.
  • a hydraulic press having a pressure chamber enclosed by a flexible die member and having a movable die plunger adapted to urge a workpiece blank into the flexible die member as the plunger is extended
  • a hydraulic motor connected to the die plunger having a port to receive fluid under pressure for extension of the plunger
  • a hydraulic pump means to connect the output of said pump to the pressure chamber
  • a cam operatively connected to the die plunger for movement as the die plunger is extended
  • a pilot relief Valve having a pilot line connected thereto and a movable valve plunger positionable in accordance with the pressure in the pilot line and the position of the cam to establish the pressure in the pilot line
  • a variable relief valve connected to said pilot line and having an inlet port and an outlet port, said inlet port connected to the pressure chamber and said outlet port connected to said port of the hydraulic motor, said variable relief valve having a movable plunger adaptable to block said outlet port in one position and shiftable from said position in response to the pressure in the pilot line and the pressure at said inlet
  • a base member having a nest ring thereon adapted to receive a workpiece blank, a die plunger received in the nest ring and having a hydraulic motor for extension therefrom, a head member having a tank and a depending cylindrical portion, said tank, said head member, and the depending portion thereof defining a reservoir for hydraulic fluid, a valve in the depending portion of the head member operable to pass fluid to and from the reservoir, a sleeve telescopically received over said depending portion of the head member in sealing relation therewith and having a flexible diaphragm enclosing the lower end thereof, said sleeve, said flexible die member, and said depending portion of the head member defining a pressure chamber, a reversible hydraulic motor connected to the sleeve to reciprocate said sleeve on the depending head portion and move the flexible die member between an open position adjacent the head portion and a closed position on the workpiece blank to expand and collapse said pressure chamber, a hydraulic pump, means to connect the pump to
  • a bed member having a die member therein, a frame member having an extending portion spaced from said bed and in registration therewith, said extending frame member portion defining a reservoir for hydraulic fluid, a casing telescopically received over said extending portion of the frame member and having a flexible die member enclosing the end toward the bed, said casing, said flexible die member, and said frame member portion defining a pressure chamber, means to reciprocate the casing on the frame member portion to move the flexible die member between the bed member and said portion of the frame member to expand and collapse said chamber, a valve in said extending frame member portion blocking flow of fluid between the reservoir and the chamber when the valve is closed, and means for controlling the opening of said valve to permit passage of hydraulic fluid between the reservoir and the chamber as the chamber expands and collapses.
  • a bed member having a die member therein, a head member having a depending cylindrical portion spaced from said bed member and in registration therewith, said depending cylindrical portion defining a reservoir for hydraulic fluid over the bed member, a cylindrical casing telescopically received over said depending portion of the head member in sealing relation therewith and having a flexible die member enclosing the end toward the bed, said casing, said flexible die member, and said head member portion defining a pressure chamber, means to reciprocate the casing on the head member portion to move the flexible die member between a position adjacent the bed member and a position adjacent said portion of the head member to expand and collapse said chamber, a valve in the bottom of said depending cylindrical head member portion operable when closed to block flow of fluid between the reservoir and the pressure chamber, said valve opening by expansion of the chamber to permit passage of fluid from the reservoir to the expanding chamber, means to supply additional fluid under pressure to the expanded chamber, and means to open the valve as the chamber collapses to permit passage of fluid from the collapsing chamber to the reservoir

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Shaping Metal By Deep-Drawing, Or The Like (AREA)
  • Press Drives And Press Lines (AREA)
  • Reciprocating Pumps (AREA)
US53444A 1960-09-01 1960-09-01 Hydraulic press Expired - Lifetime US3115858A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
US53444A US3115858A (en) 1960-09-01 1960-09-01 Hydraulic press
GB16976/61A GB901278A (en) 1960-09-01 1961-05-10 Hydraulic press
DEC28488A DE1279607B (de) 1960-09-01 1961-05-19 Hydraulische Membranziehpresse zur Blechbearbeitung
DEC24161A DE1196154B (de) 1960-09-01 1961-05-19 Hydraulische Formpresse zur Blechbearbeitung
FR863648A FR1290717A (fr) 1960-09-01 1961-06-01 Perfectionnements apportés aux dispositifs de presse pour emboutissage hydraulique
NL6905724A NL6905724A (enExample) 1960-09-01 1969-04-14

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US53444A US3115858A (en) 1960-09-01 1960-09-01 Hydraulic press

Publications (1)

Publication Number Publication Date
US3115858A true US3115858A (en) 1963-12-31

Family

ID=21984275

Family Applications (1)

Application Number Title Priority Date Filing Date
US53444A Expired - Lifetime US3115858A (en) 1960-09-01 1960-09-01 Hydraulic press

Country Status (5)

Country Link
US (1) US3115858A (enExample)
DE (2) DE1279607B (enExample)
FR (1) FR1290717A (enExample)
GB (1) GB901278A (enExample)
NL (1) NL6905724A (enExample)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1291313B (de) * 1964-04-09 1969-03-27 Cincinnati Milling Machine Co Biegsame Membran als Verschluss fuer die Druckkammer einer hydraulischen Tiefziehpresse

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2696183A (en) * 1949-10-01 1954-12-07 Hydro Form Corp Press
US2761405A (en) * 1953-12-14 1956-09-04 Svenska Aeroplan Ab Hydraulic forming attachment for presses
US2766711A (en) * 1950-08-09 1956-10-16 Cincinnati Milling Machine Co Press
FR1217001A (fr) * 1957-11-06 1960-04-29 Boulton Aircraft Ltd Perfectionnements à l'emboutissage de métal ou autre matière en feuille
US2937606A (en) * 1956-02-20 1960-05-24 Cincinnati Milling Machine Co Metal forming press
US3046923A (en) * 1958-07-25 1962-07-31 Yolin Maurice Hydraulic stamping press with a die made of resilient material

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2783728A (en) * 1951-09-12 1957-03-05 Lake Erie Engineering Corp Apparatus for pressing sheet metal shapes
US2878767A (en) * 1954-01-04 1959-03-24 Cincinnati Milling Machine Co Forming press diaphragm
FR1210040A (fr) * 1958-07-25 1960-03-04 Presse à emboutir hydraulique à matrice en matière élastique

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2696183A (en) * 1949-10-01 1954-12-07 Hydro Form Corp Press
US2766711A (en) * 1950-08-09 1956-10-16 Cincinnati Milling Machine Co Press
US2761405A (en) * 1953-12-14 1956-09-04 Svenska Aeroplan Ab Hydraulic forming attachment for presses
US2937606A (en) * 1956-02-20 1960-05-24 Cincinnati Milling Machine Co Metal forming press
FR1217001A (fr) * 1957-11-06 1960-04-29 Boulton Aircraft Ltd Perfectionnements à l'emboutissage de métal ou autre matière en feuille
US3046923A (en) * 1958-07-25 1962-07-31 Yolin Maurice Hydraulic stamping press with a die made of resilient material

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1291313B (de) * 1964-04-09 1969-03-27 Cincinnati Milling Machine Co Biegsame Membran als Verschluss fuer die Druckkammer einer hydraulischen Tiefziehpresse

Also Published As

Publication number Publication date
NL6905724A (enExample) 1969-07-25
DE1196154B (de) 1965-07-08
GB901278A (en) 1962-07-18
DE1279607B (de) 1968-10-10
FR1290717A (fr) 1962-04-13

Similar Documents

Publication Publication Date Title
US3357218A (en) Hydraulic press
US3290919A (en) High pressure hydraulic forming press
US2407855A (en) Hydraulic press system
US2218818A (en) Hydraulic die spotting press
US2316944A (en) Valve
US2009487A (en) Hydraulic press
US2350884A (en) Blank holder and die cushion cylinder having separate adjustable pressures
US2294451A (en) Blank holder and die cushion cylinder having separate adjustable pressures
US3115858A (en) Hydraulic press
US4958548A (en) Hydraulic drive mechanism
US5237916A (en) Regenerative hydraulic cylinders with internal flow paths
EP0551624B1 (en) Multi-stage hydraulic actuator
US2305610A (en) Press with die cushion
US2357019A (en) Hydraulic double-action draw press
GB1562344A (en) Apparatus for the removal of superfluous or unwanted projection from articles
US2683966A (en) Hydraulic press
US2030966A (en) Variable pressure apparatus
US1956758A (en) Hydraulic press operating circuits
US2269778A (en) Metal working press
US2249964A (en) Electrically controlled hydraulic turret press
US2258981A (en) Selective delivery reduction means for variable delivery pumps
US2390359A (en) Triple action automobile body press
US2790305A (en) Control valves for hydraulic presses
US2343177A (en) Hydraulic press
US2229965A (en) Hydraulic press circuit