US3911679A - Closed center hydraulic system with pump and accumulator output for high speed lift - Google Patents
Closed center hydraulic system with pump and accumulator output for high speed lift Download PDFInfo
- Publication number
- US3911679A US3911679A US536564A US53656474A US3911679A US 3911679 A US3911679 A US 3911679A US 536564 A US536564 A US 536564A US 53656474 A US53656474 A US 53656474A US 3911679 A US3911679 A US 3911679A
- Authority
- US
- United States
- Prior art keywords
- accumulator
- pump
- control valve
- switch
- valve
- 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
Links
Images
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
- F15B1/00—Installations or systems with accumulators; Supply reservoir or sump assemblies
- F15B1/02—Installations or systems with accumulators
-
- 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
- F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
-
- 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
- F15B2211/2053—Type of pump
-
- 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
- F15B2211/21—Systems with pressure sources other than pumps, e.g. with a pyrotechnical charge
- F15B2211/212—Systems with pressure sources other than pumps, e.g. with a pyrotechnical charge the pressure sources being accumulators
-
- 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
- F15B2211/265—Control of multiple pressure sources
-
- 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
- F15B2211/40576—Assemblies of multiple valves
- F15B2211/40584—Assemblies of multiple valves the flow control means arranged in parallel with a check 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
- F15B2211/40—Flow control
- F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
- F15B2211/41509—Flow control characterised by the connections of the flow control means in the circuit being connected to a pressure source and a directional control valve
- F15B2211/41518—Flow control characterised by the connections of the flow control means in the circuit being connected to a pressure source and a directional control valve being connected to multiple pressure sources
-
- 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
- F15B2211/41527—Flow control characterised by the connections of the flow control means in the circuit being connected to an output member and a directional control 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
- F15B2211/40—Flow control
- F15B2211/46—Control of flow in the return line, i.e. meter-out control
-
- 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
- F15B2211/47—Flow control in one direction only
- F15B2211/473—Flow control in one direction only without restriction in the reverse direction
-
- 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
- F15B2211/515—Pressure control characterised by the connections of the pressure control means in the circuit
- F15B2211/5151—Pressure control characterised by the connections of the pressure control means in the circuit being connected to a pressure source and a directional control 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
- F15B2211/50—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
- F15B2211/60—Circuit components or control therefor
- F15B2211/63—Electronic controllers
- F15B2211/6303—Electronic controllers using input signals
- F15B2211/6306—Electronic controllers using input signals representing a pressure
- F15B2211/6309—Electronic controllers using input signals representing a pressure the pressure being a pressure source supply 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
- F15B2211/60—Circuit components or control therefor
- F15B2211/665—Methods of control using electronic components
- F15B2211/6651—Control of the prime mover, e.g. control of the output torque or rotational speed
-
- 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
- F15B2211/71—Multiple output members, e.g. multiple hydraulic motors or cylinders
-
- 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
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S60/00—Power plants
- Y10S60/911—Fluid motor system incorporating electrical system
Definitions
- a single pump and pump motor are used in conjunction with a relatively large capacity accumulator to supply the normal hydraulic needs of the various control functions of the lift truck including steering, lifting, mast tilting and attachment control.
- the operator may shift the lift control valve to its raise position and achieve a needed flow from minimum to maximum as the control valve is moved to its full raise position.
- a resilient cushion is compressed and a switch is actuated to cause the'pump contactor to close thereby putting the pump into operation to supply fluid in addition to that being supplied from the accumulator.
- the pump contactor is also operated by a pressure sensitive control which maintains the accumulator pressure between predetermined minimum and maximum values.
- This invention provides the desired high speed lift function without necessitating the expense of a large pump or additional pumps.
- the large capacity accumulator permits a standard size pump and motor to be operated only to maintain the accumulator fluid pressure in its predetermined range.
- the accumulator provides an emergency supply of pressure fluid for steering in event of pump, pump motor or battery failure.
- a hydraulic control system for a lift truck includes a lift jack 11, a pair of tilt jacks 12, 13 and a reversible steering motor 14.
- a single hydraulic pump 16 has its intake line 17 connected with a fluid reservoir 18 and has its fluid delivery line 19 connected to a large accumulator 21.
- a check valve 22 is provided to prevent discharge of the accumulator 21 to the pump 16. Flow to the accumulator is by way of a check valve 23 and restrictor 24.
- the pump 16 is driven by an electric motor 26 which is connected to the vehicle storage battery 27 by a contactor circuit 28 which includes a solenoid operated contactor 29 having a contact 31.
- the solenoid of the contactor 29 is connected by a circuit 32 to the battery 27 by way of a solenoid operated double pole switch 33 which is controlled by low and high pressure switches 34, 36 pilot operated by the pressure in the accumulator 21 by way of hydraulic lines shown by dash lines 37, 38.
- an ignition switch 35 is open and the accumulator is discharged.
- double pole switch 33 closes thus energizing the contactor coil causing the contactor 29 to close.
- the motor 26 now drives the pump to deliver pressure fluid to the accumulator.
- the pressure switch 34 will open; however, a holding circuit established through the high pressure switch 36 will maintain the double pole solenoid switch 33 closed until pressure reaches a predetermined maximum value at which time the pressure switch 36 will open to interrupt power to the solenoid of switch 33 thereby causing it to open.
- the opening of switch 33 will cause the contactor 29 to open thereby stopping the pump motor 26.
- the high pressure switch 36 When fluid is discharged from the accumulator during operation of the lift truck, the high pressure switch 36 will close; however, a circuit is not completed to energize the double pole switch 33 and the motor will not run until the low pressure switch 34 closes upon sensing a predetermined minimum value of pressure in the accumulator 21.
- Pressure fluid from the accumulator 21 is used for steering under the control of an appropriate closed center valve 41 connected to the accumulator by delivery line 42 and connected to reservoir by return line 43.
- the steering control valve 41 is connected to opposite ends of the reversible hydraulic motor 14 by delivery lines 44, 46. Fluid returned to reservoir by return line 43 passes through a filter 47 A bypass valve 48 is connected in parallel with the filter 47 so as to permit return flow in case the filter becomes plugged.
- a relief valve 51 is provided which will open at a predetermined pressure slightly above the maximum pressure setting for the high pressure switch 36.
- Closed center control valves 56, 57, 58 are associated with the lift jack 11, tilt jacks 12, 13 and a lift truck attachment, not shown.
- a fluid delivery line 61 interconnects the accumulator 21 and the metering type lift valve 56.
- the valve 56 is connected to reservoir by a return line 62.
- the lift jack 11 is connected to the control valve 56 by a delivery line 63 in which a flow regulator 64 is operatively disposed.
- the parallel connected restrictor 66 and check valve 67 of the flow regulator regulate outflow of fluid from the jack 1 1 and permit relatively free fluid flow to the jack 11.
- the lever 71 is pivoted on the chassis 72 of the lift truck by a pivot pin 73 and includes an arm pivotally connected to a threaded rod 74 by a pin 76.
- the threaded rod 74 is connected at its lower end to the flow control element or spool 75.
- a slight amount of additional force on the lever 71 will compress the resilient elastometer washer 81 and permit a slight additional movement of the rod 74 upwardly thereby causing a cam 83 to move a switch operating lever 84 sufficiently to actuate an electric switch 86.
- the switch 86 is in a motor operating circuit 87 connected in parallel with the pressure sensitive switch operating control means and on closing of switch 86 the solenoid of the contactor 29 will be energized to close the contactor and provide electric power to the motor 26.
- the relief valve 51 will open at its predetermined pressure relief setting to discharge to reservoir to protect the pump and accumulator when the operator is operating the motor independently of the pressure sensitive controls therefor.
- the resilient washer is mounted on a nut 91 on the threaded portion of rod 74.
- the cam 83 also includes a nut portion 92 threadedly engaging the threaded portion of the rod 74. The axial position of the cam 83 and washer 81 can be adjusted to obtain proper metering control in raise position of control valve 56 and the desired operation of switch 86 upon predetermined compression of the resilient washer 81.
- the present invention permits a relatively small electric pump motor and pump to be utilized to charge a relatively large accumulator 21 and the operator may select the high speed lift function on those occasions when the higher speed is desirable.
- the electric control means for placing the pump in operation independently of the pressure sensitive electric control means includes a manually operable switch which can be operated only when the lift valve is placed in its raise position.
- a two speed lift system for a lift truck comprising:
- a pump connected in fluid receiving relation to said reservoir and fluid delivery relation to said accumulator
- first electric control means operatively associated with said motor, source of electric energy and accumulator automatically maintaining the pressure in said accumulator between predetermined minimum and maximum values
- second electric control means including a manually operable switch for selectively energizing said electric motor to cause same to drive said pump independently of the value of the pressure in said accumulator when said switch is actuated, said lift jack being supplied with fluid from said accumulator when said control valve is placed in its raise position of adjustment of said manually operable switch is not actuated
- said lift jack being supplied with fluid from said accumulator and from said pump when said control valve is placed in its raise position of adjustment and said manually operable switch is actuated.
- control valve is a metering type valve with a predetermined metering range in its raise position between partial flow and full flow positions and wherein said manually operable switch is actuatable only when said control valve is ad justed in said metering range to said full flow position.
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Forklifts And Lifting Vehicles (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
Description
Claims (8)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US536564A US3911679A (en) | 1974-12-26 | 1974-12-26 | Closed center hydraulic system with pump and accumulator output for high speed lift |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US536564A US3911679A (en) | 1974-12-26 | 1974-12-26 | Closed center hydraulic system with pump and accumulator output for high speed lift |
Publications (1)
Publication Number | Publication Date |
---|---|
US3911679A true US3911679A (en) | 1975-10-14 |
Family
ID=24139031
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US536564A Expired - Lifetime US3911679A (en) | 1974-12-26 | 1974-12-26 | Closed center hydraulic system with pump and accumulator output for high speed lift |
Country Status (1)
Country | Link |
---|---|
US (1) | US3911679A (en) |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4002220A (en) * | 1975-07-11 | 1977-01-11 | Towmotor Corporation | Priority steer system--hydraulic |
US4056160A (en) * | 1975-01-03 | 1977-11-01 | Linde Aktiengesellschaft | Electrically powered vehicle with power steering |
US4099378A (en) * | 1977-01-17 | 1978-07-11 | Caterpillar Tractor Co. | Blocking valve for power steering for lift trucks |
US4100739A (en) * | 1977-01-17 | 1978-07-18 | Caterpillar Tractor Co. | Pressure sensitive charging means for a steering system |
US4332270A (en) * | 1978-08-23 | 1982-06-01 | Itt Industries, Inc. | Flow control and accumulator charging valve |
US4567894A (en) * | 1984-11-09 | 1986-02-04 | General Electric Company | Hydraulically operated, mobile patient transport table useful with a magnetic resonance scanner |
US4667472A (en) * | 1984-12-28 | 1987-05-26 | The Boeing Company | Electric integrated actuator with variable gain hydraulic output |
US4748809A (en) * | 1984-07-31 | 1988-06-07 | Aisin-Warner Limited | Hydraulic servo mechanism of automatic transmission for vehicle |
EP0442860A1 (en) * | 1990-01-16 | 1991-08-21 | W. Everaert Pvba | Machine for destroying concrete surfaces |
US5317870A (en) * | 1991-05-22 | 1994-06-07 | Honda Giken Kogyo Kabushiki Kaisha | Pressure source for pressure device |
US20020092393A1 (en) * | 2000-06-01 | 2002-07-18 | Doug Mains | Traversing circular saw |
US20080016838A1 (en) * | 2006-07-20 | 2008-01-24 | Pellenc Iberica Sl | Vibrating tongs with an adaptable clamping force for fruit harvesting |
US20150122564A1 (en) * | 2012-04-27 | 2015-05-07 | Isuzu Motors Limited | Hydraulic circuit for vehicle, vehicle equipped with same, and control method therefor |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2323519A (en) * | 1941-01-24 | 1943-07-06 | Ternstedt Mfg Co | Vacuum operated window regulator |
US2674092A (en) * | 1952-09-04 | 1954-04-06 | Vickers Inc | Power transmission |
US2968927A (en) * | 1960-01-28 | 1961-01-24 | Yale & Towne Mfg Co | Hydraulic system for an industrial truck |
US3434282A (en) * | 1967-03-14 | 1969-03-25 | Dura Corp | Safety backup system for power steering |
-
1974
- 1974-12-26 US US536564A patent/US3911679A/en not_active Expired - Lifetime
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2323519A (en) * | 1941-01-24 | 1943-07-06 | Ternstedt Mfg Co | Vacuum operated window regulator |
US2674092A (en) * | 1952-09-04 | 1954-04-06 | Vickers Inc | Power transmission |
US2968927A (en) * | 1960-01-28 | 1961-01-24 | Yale & Towne Mfg Co | Hydraulic system for an industrial truck |
US3434282A (en) * | 1967-03-14 | 1969-03-25 | Dura Corp | Safety backup system for power steering |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4056160A (en) * | 1975-01-03 | 1977-11-01 | Linde Aktiengesellschaft | Electrically powered vehicle with power steering |
US4002220A (en) * | 1975-07-11 | 1977-01-11 | Towmotor Corporation | Priority steer system--hydraulic |
US4099378A (en) * | 1977-01-17 | 1978-07-11 | Caterpillar Tractor Co. | Blocking valve for power steering for lift trucks |
US4100739A (en) * | 1977-01-17 | 1978-07-18 | Caterpillar Tractor Co. | Pressure sensitive charging means for a steering system |
US4332270A (en) * | 1978-08-23 | 1982-06-01 | Itt Industries, Inc. | Flow control and accumulator charging valve |
US4748809A (en) * | 1984-07-31 | 1988-06-07 | Aisin-Warner Limited | Hydraulic servo mechanism of automatic transmission for vehicle |
US4567894A (en) * | 1984-11-09 | 1986-02-04 | General Electric Company | Hydraulically operated, mobile patient transport table useful with a magnetic resonance scanner |
US4667472A (en) * | 1984-12-28 | 1987-05-26 | The Boeing Company | Electric integrated actuator with variable gain hydraulic output |
EP0442860A1 (en) * | 1990-01-16 | 1991-08-21 | W. Everaert Pvba | Machine for destroying concrete surfaces |
BE1003135A3 (en) * | 1990-01-16 | 1991-12-03 | P V B A W Everaert | MACHINE FOR CRUSHING CONCRETE SURFACES. |
US5317870A (en) * | 1991-05-22 | 1994-06-07 | Honda Giken Kogyo Kabushiki Kaisha | Pressure source for pressure device |
US20020092393A1 (en) * | 2000-06-01 | 2002-07-18 | Doug Mains | Traversing circular saw |
US20080016838A1 (en) * | 2006-07-20 | 2008-01-24 | Pellenc Iberica Sl | Vibrating tongs with an adaptable clamping force for fruit harvesting |
US7810306B2 (en) * | 2006-07-20 | 2010-10-12 | Pellenc Iberica, Sl | Vibrating tongs with an adaptable clamping force for fruit harvesting |
US20150122564A1 (en) * | 2012-04-27 | 2015-05-07 | Isuzu Motors Limited | Hydraulic circuit for vehicle, vehicle equipped with same, and control method therefor |
US9114697B2 (en) * | 2012-04-27 | 2015-08-25 | Isuzu Motors Limited | Hydraulic circuit for vehicle, vehicle equipped with same, and control method therefor |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: CONNECTICUT NATIONAL BANK THE, A NATIONAL BANKING Free format text: SECURITY INTEREST;ASSIGNOR:ALLIS-CHALMERS CORPORATION A DE CORP.;REEL/FRAME:004149/0001 Effective date: 19830329 Owner name: WOODS KATHLEEN D., AS TRUSTEE Free format text: SECURITY INTEREST;ASSIGNOR:ALLIS-CHALMERS CORPORATION A DE CORP.;REEL/FRAME:004149/0001 Effective date: 19830329 |
|
AS | Assignment |
Owner name: AC MATERIAL HANDLING CORPORATION, 777 MANOR PARK D Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:ALLIS-CHALMERS CORPORATION, A CORP. OF DE.;REEL/FRAME:004615/0183 |
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AS | Assignment |
Owner name: FIRST NATIONAL BANK OF CHICAGO, THE Free format text: SECURITY INTEREST;ASSIGNOR:AC MATERIAL HANDLING CORPORATION, AN OH CORP;REEL/FRAME:004648/0689 Effective date: 19860731 |
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Owner name: ALLIS-CHALMERS CORPORATION, BOX 512, MILWAUKEE, WI Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:CONNECTICU NATIONAL BANK, THE;REEL/FRAME:004680/0807 Effective date: 19860714 Owner name: ALLIS-CHALMERS CORPORATION, BOX 512, MILWAUKEE, WI Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:CONNECTICUT NATIONAL BANK, THE;REEL/FRAME:004686/0798 Effective date: 19860719 Owner name: ALLIS-CHALMERS CORPORATION,WISCONSIN Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:CONNECTICUT NATIONAL BANK, THE;REEL/FRAME:004686/0798 Effective date: 19860719 |