US2980064A - Control units for hydraulic rams - Google Patents

Control units for hydraulic rams Download PDF

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Publication number
US2980064A
US2980064A US842311A US84231159A US2980064A US 2980064 A US2980064 A US 2980064A US 842311 A US842311 A US 842311A US 84231159 A US84231159 A US 84231159A US 2980064 A US2980064 A US 2980064A
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United States
Prior art keywords
valve
ram
pressure
return
chamber
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
US842311A
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English (en)
Inventor
Norton Henry
Norton Hubert Veare
Norton Leslie Buckingham
Norton Douglas Edwin
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.)
Norton Tool Co Ltd
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Norton Tool Co Ltd
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Filing date
Publication date
Application filed by Norton Tool Co Ltd filed Critical Norton Tool Co Ltd
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Publication of US2980064A publication Critical patent/US2980064A/en
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Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q5/00—Driving or feeding mechanisms; Control arrangements therefor
    • B23Q5/22—Feeding members carrying tools or work
    • B23Q5/26—Fluid-pressure drives
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B15/00—Details of, or accessories for, presses; Auxiliary measures in connection with pressing
    • B30B15/16—Control arrangements for fluid-driven presses
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/20576—Systems with pumps with multiple pumps
    • F15B2211/20592—Combinations of pumps for supplying high and low pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30505—Non-return valves, i.e. check valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/405—Flow control characterised by the type of flow control means or valve
    • F15B2211/40507—Flow control characterised by the type of flow control means or valve with constant throttles or orifices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/405—Flow control characterised by the type of flow control means or valve
    • F15B2211/40515—Flow control characterised by the type of flow control means or valve with variable throttles or orifices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
    • F15B2211/41563—Flow control characterised by the connections of the flow control means in the circuit being connected to a pressure source and a return line
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
    • F15B2211/41581—Flow control characterised by the connections of the flow control means in the circuit being connected to an output member and a return line
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/42—Flow control characterised by the type of actuation
    • F15B2211/421—Flow control characterised by the type of actuation mechanically
    • F15B2211/423—Flow control characterised by the type of actuation mechanically manually, e.g. by using a lever or pedal
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/42—Flow control characterised by the type of actuation
    • F15B2211/426—Flow control characterised by the type of actuation electrically or electronically
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/45—Control of bleed-off flow, e.g. control of bypass flow to the return line
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/505—Pressure control characterised by the type of pressure control means
    • F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
    • F15B2211/50518—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using pressure relief valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/55—Pressure control for limiting a pressure up to a maximum pressure, e.g. by using a pressure relief valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
    • F15B2211/7051—Linear output members
    • F15B2211/7053—Double-acting output members
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/75—Control of speed of the output member
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/755—Control of acceleration or deceleration of the output member
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/76—Control of force or torque of the output member
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/7722—Line condition change responsive valves
    • Y10T137/7837—Direct response valves [i.e., check valve type]
    • Y10T137/7904—Reciprocating valves
    • Y10T137/7922—Spring biased
    • Y10T137/7929—Spring coaxial with valve

Definitions

  • This invention relates'to control units for hydraulic rams suitable for numerous applications, for instance, for actuating machine tools such as hydraulic presses, shapers and slotters, power transmission systems, mechanical handling equipment and rock drills.
  • control unit of the invention is applicable more particularly, but not exclusively, to the hydraulic ram apparatus described in the present applicants co-pending patent application No. 842,509 filed concurrently here'- with.
  • the unloader valve may comprise a cylinder containing a spring-loaded piston of relatively large area controlling a port in the cylinder wall and carrying a closure member which can seat on a seating of much smaller area than the piston and communicating with the pressure chamber of the ram, such that the closure member is lifted from its seating by the said predetermined high pressure and a space on the closure member side of the piston thereupon communicates with the said pressure chamber, the port being disposed so that fluid is trapped in this space to prevent complete closure of the valve until the trapped fluid is released from this space.
  • the unloader valve of the control unit acts as a means for stopping the working stroke and initiating the return stroke automatically.
  • the release valve therefore constitutes a single control giving single working strokes followed by an automatic return stroke of controllable length and with a controllable dwell before the next working stroke.
  • the loading of the unloader valve spring may be adjustable so that the predetermined high pressure at which the unloader valve opens and hence the maximum working force exerted by the ram can be varied as required.
  • a further extension of the effects achievable by the control unit is provided if an adjustable bleed valve is connected in parallel with the release valve.
  • the bleed valve permits leakage of fluid trapped in the space in the unloader valve at a controlled rate and therefore permits the unloader valve to close automatically after a controllable delay. This provides automatic multi-strokeop- 'ice eration with a controllable dwell at the end of the return stroke.
  • the bleed valve can also provide for a series of short strokes in rapid succession, the length and the frequency of the strokes being variable by adjusting the bleed valve.
  • the control unit may also include a separately actuated control valve communicating with the pressure chamber of the ram and operable to control release of pressure from this chamber independently of the unloader valve of the control unit.
  • a separately actuated control valve communicating with the pressure chamber of the ram and operable to control release of pressure from this chamber independently of the unloader valve of the control unit.
  • the invention is applied to a hydraulic ram control system in which the underside of the ram piston is under pressure at all times, since in such a system ram reversal is achieved virtually instantaneously in response to actuation of the unloader valve on the separately actuated control valve, permitting very rapid multi-stroke operation.
  • control unit and the hydraulic ram apparatus are depicted in a highly diagrammatic form, with the object of illustrating the principles of the invention and the way the various parts of the control unit operate rather than the details of design and construction.
  • the hydraulic ram apparatus comprises a double-acting hydraulic ram 10, depicted in this case as applied to a hydraulic press.
  • the pressure chamber 11 and the return chamber 12 of the ram are connected together by a connecting passage 13 which includes a restrictor valve 14, preferably an automatic unloader valve as described in the said co-pending application.
  • the connecting passage 1'3 is supplied with hydraulic fluid from a high pressure pump 15.
  • a low pressure pump 16 which can deliver fluid to the pressure chamber 11 through a non-return valve 17.
  • a relief valve 18 is provided for venting the low pressure pump to a return line 19 when the non-return valve 17 is closed.
  • a control unit 21 Also communicating with the pressure chamber 11 through a line 20 is a control unit 21.
  • This has an inlet chamber 22 with which the line 20 is in permanent communication and a return chamber 23 which is in permanent communication with the return line 19.
  • Communicating with the inlet chamber 21 is a passage 24 equipped with a control valve 25. When this valve is open, fluid can flow out from the pressure chamber 11 through the line 20, the inlet passage 22, the passage 24 and the control valve 25 into the return passage 23, and then out through the return line 19.
  • the control valve 25 is actuated directly by an actuating member 26, through a rod 27.
  • the fluid pressure at which it will open is a function of the force applied to the actuating pressure supply to the pressure chamber 11 to maintain the fluid pressure on the ram at the desired value, this value being adjustable by pressing more or less heavily on the adjusting member 26.
  • the working stroke can be stopped by raising the adjusting member 26, and a new working stroke begun by lowering it again.
  • the control valve 25 actuated by the adjusting member 26 therefore provides manual control over the individual working and return strokes, and control over the working force of the ram.
  • the control valve 25 corresponds in functioning and effect to the control valve of the apparatus described in the said co-pending application.
  • the control unit 21 of the present invention also provides additional effects.
  • One such effect is provided by an unloader valve 28.
  • This consists of a cylinder 2% in which can slide a piston 30 which is loaded towards the left in the drawing by a spring 31.
  • the right-hand abutment '32 of this spring is adjustable by an adjustment screw 33.
  • a pin 34 fixed to the piston 30 bears against the head of a valve 35 which when open permits fluid from the inlet chamber 22 to enter a chamber 36.
  • the valve 35 is closed the pressure in the inlet chamber 22 acts only on the area of the valve, but as soon as the valve 35 begins to open the pressure in the chamber 22 is applied to the whole area of the piston 30, and continues to be applied to that large area so long as the valve 35 remains open.
  • the unloader valve 28 acts as a means for stopping the working stroke of the ram and initiating the return stroke automatically on the attainment of a predetermined high pressure in the pressure chamber 11.
  • the unloader valve 2% will be opened and will vent the pressure chamber 11 to the return line 19, through the line 20, the inlet chamber 22, the valve 35, the chamber 36, the port 37 and the return passage 23. This will permit the pressure in the return chamber 12 to return the ram.
  • bleed passage 40 controlled by an adjustable bleed valve 41.
  • This valve permits the trapped fluid to escape at a controlled rate and therefore'permits the unloader valve 28 to close automatically after an adjustable delay. This provides automatic multi-stroke operation with an adjustable dwell at the end of the return stroke. If the bleed valve 41 is opened more widely it is possible to terminate the return stroke automatically before its normal completion and begin a new working stroke immediately, providing a series of short strokes in rapid succession, the length and frequency of the strokes being variable by adjusting the bleed valve 41.
  • the various controls and adjustments of the control unit may be actuated manually as illustrated, or one or more may be actuated automatically depending on the degree of automatic operation required in the particular installation.
  • the release valve 38 may be actuated automatically by the ram at the end of the return stroke to provide multi-stroke operation. This would enable the bleed valve 41 to be dispensed with, but for many installations the bleed valve is a more flexible way of achieving a similar result.
  • Automatic actuation may also be effected to co-ordinate and synchronise the movements of the ram with other operations performed by the same or different machines.
  • the actual form of the automatic actuating mechanism may vary widely' depending upon the nature of the installation and other factors. For instance, hydraulic, electrical or mechanical actuators and transmission links may be employed.
  • a control unit for a hydraulic ram having a pressure chamber comprising an unloader valve, a release valve, said unloader valve comprising a cylinder having a side wall provided with a port and end walls, a piston of relatively large area slidable in said cylinder and controlling said port, an inlet connection to said cylinder in one of said end walls thereof, a seating adjacent said inlet connection of relatively small area, an inlet closure member carried by said piston and seatable on said seating, passage means connecting said inlet connection to said pressure chamber of said ram, a spring acting on said piston and urging said piston towards a closed position in which said closure member engages said seating and said ports is closed, said piston having also an open position in which said closure member is off its seating and said part is exposed, said piston being movable'from said closed position by the attainment of a predetermined high pressure at said inlet connection and being maintainable in said open position by a pressure substantially below said predetermined high pressure, said piston also having an intermediate position in which said port is closed but
  • a control unit in which said spring has an adjustable abutment whereby the loading of said spring is adjustable.
  • a control unit which includes an adjustable bleed valve connected in parallel with said release valve to provide controlled slow closure of said unloader valve with said release valve closed.
  • a control unit which includes a control valve, actuating means for said control valve,
  • control unit in which said control valve comprises an actuating member adapted for manual operation, a seating, a closure member, and means connecting said actuating member to said closure member whereby a force applied to said actuating member urges said closure member towards its seating with a force which is a function of the force applied to said actuating member.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Earth Drilling (AREA)
US842311A 1958-10-01 1959-09-25 Control units for hydraulic rams Expired - Lifetime US2980064A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB355353X 1958-10-01

Publications (1)

Publication Number Publication Date
US2980064A true US2980064A (en) 1961-04-18

Family

ID=10378806

Family Applications (1)

Application Number Title Priority Date Filing Date
US842311A Expired - Lifetime US2980064A (en) 1958-10-01 1959-09-25 Control units for hydraulic rams

Country Status (5)

Country Link
US (1) US2980064A (cs)
CH (1) CH355353A (cs)
DE (1) DE1106571B (cs)
GB (1) GB872950A (cs)
NL (1) NL243892A (cs)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3132485A (en) * 1961-03-31 1964-05-12 Blackhawk Mfg Co Hydraulic motor control
US3162094A (en) * 1962-01-08 1964-12-22 David H Lipsey Fluid actuated reciprocating mechanism and controls therefor
US3176466A (en) * 1961-12-01 1965-04-06 American Brake Shoe Co Hydraulic press
US3229719A (en) * 1963-05-06 1966-01-18 Pall Corp Pneumatic rotary gas valve
US3424057A (en) * 1965-04-21 1969-01-28 Werner & Pfleiderer Hydraulic pressure control system
US3643547A (en) * 1968-09-18 1972-02-22 Philips Corp Hydraulic reciprocating engine
US3707844A (en) * 1971-08-03 1973-01-02 Ranco Inc Hydraulic actuator
US3918350A (en) * 1973-01-15 1975-11-11 Poclain Sa Pressurized fluid controlled vibrators

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2665554A (en) * 1944-05-06 1954-01-12 Borg Warner Hydraulic power control system
US2770222A (en) * 1953-05-13 1956-11-13 Anderson James Hydraulic system of lathes and other metal working machines, presses, and the like

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2680447A (en) * 1954-06-08 Unloading device
DE108082C (cs) *
DE680291C (de) * 1936-06-03 1939-08-25 Carl Koenig Fliessdruckeinrichtung zur Betaetigung bewegbarer Flugzeugbauteile
GB576167A (en) * 1943-02-20 1946-03-21 Bendix Aviat Corp Improvements in or relating to fluid pressure regulating valves
US2756771A (en) * 1951-05-25 1956-07-31 Sperry Gyroscope Co Ltd Pressure-regulating valves for hydraulic systems
DE1006685B (de) * 1951-07-11 1957-04-18 Electraulic Presses Ltd Einrichtung zur Regelung des Druckes innerhalb enger Grenzen in einer hydraulischen Anlage und/oder einem Speicher

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2665554A (en) * 1944-05-06 1954-01-12 Borg Warner Hydraulic power control system
US2770222A (en) * 1953-05-13 1956-11-13 Anderson James Hydraulic system of lathes and other metal working machines, presses, and the like

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3132485A (en) * 1961-03-31 1964-05-12 Blackhawk Mfg Co Hydraulic motor control
US3176466A (en) * 1961-12-01 1965-04-06 American Brake Shoe Co Hydraulic press
US3162094A (en) * 1962-01-08 1964-12-22 David H Lipsey Fluid actuated reciprocating mechanism and controls therefor
US3229719A (en) * 1963-05-06 1966-01-18 Pall Corp Pneumatic rotary gas valve
US3424057A (en) * 1965-04-21 1969-01-28 Werner & Pfleiderer Hydraulic pressure control system
US3643547A (en) * 1968-09-18 1972-02-22 Philips Corp Hydraulic reciprocating engine
US3707844A (en) * 1971-08-03 1973-01-02 Ranco Inc Hydraulic actuator
US3918350A (en) * 1973-01-15 1975-11-11 Poclain Sa Pressurized fluid controlled vibrators

Also Published As

Publication number Publication date
NL243892A (cs) 1900-01-01
DE1106571B (de) 1961-05-10
CH355353A (fr) 1961-06-30
GB872950A (en) 1961-07-12

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