GB2085971A - Composite control valve means for operating working machines - Google Patents

Composite control valve means for operating working machines Download PDF

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Publication number
GB2085971A
GB2085971A GB8126311A GB8126311A GB2085971A GB 2085971 A GB2085971 A GB 2085971A GB 8126311 A GB8126311 A GB 8126311A GB 8126311 A GB8126311 A GB 8126311A GB 2085971 A GB2085971 A GB 2085971A
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GB
United Kingdom
Prior art keywords
valve
composite
valve means
control valve
actuator
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.)
Granted
Application number
GB8126311A
Other versions
GB2085971B (en
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.)
Shibaura Machine Co Ltd
Original Assignee
Toshiba Machine Co Ltd
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 Toshiba Machine Co Ltd filed Critical Toshiba Machine Co Ltd
Publication of GB2085971A publication Critical patent/GB2085971A/en
Application granted granted Critical
Publication of GB2085971B publication Critical patent/GB2085971B/en
Expired 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
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/17—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors using two or more pumps
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2221—Control of flow rate; Load sensing arrangements
    • E02F9/2239—Control of flow rate; Load sensing arrangements using two or more pumps with cross-assistance
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2278—Hydraulic circuits
    • E02F9/2292—Systems with two or more pumps
    • 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
    • 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
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3105—Neutral or centre positions
    • F15B2211/3116—Neutral or centre positions the pump port being open in the centre position, e.g. so-called open centre
    • 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
    • F15B2211/355—Pilot pressure 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
    • F15B2211/405—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
    • F15B2211/41554—Flow control characterised by the connections of the flow control means in the circuit being connected to a return line 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
    • F15B2211/42—Flow control characterised by the type of actuation
    • F15B2211/428—Flow control characterised by the type of actuation actuated by fluid 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
    • F15B2211/40—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
    • F15B2211/50—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
    • F15B2211/5157—Pressure control characterised by the connections of the pressure 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
    • F15B2211/50—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
    • F15B2211/71—Multiple output members, e.g. multiple hydraulic motors or cylinders
    • F15B2211/7142—Multiple output members, e.g. multiple hydraulic motors or cylinders the output members being arranged in multiple groups
    • 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
    • F15B2211/78—Control of multiple output members

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Operation Control Of Excavators (AREA)

Abstract

In a composite control valve means for operating an actuator 7 of a working machine of the type comprising a pair of oil pumps 5, 13, and at least two composite valve means 21, 25, connected between the oil pumps and the actuator, each composite valve means including a plurality of control valves, there are provided a selector valve 23 integral with one control valve of one composite valve means and operated by the one control valve for controlling communication between a pilot passage 24 and a drain tank 15, a check valve 29 connected between one side of the actuator and a bypass passage 28 of the other composite valve means, and a logic valve 27 responsive to pressure in the pilot passage for controlling communication between the bypass passage and the drain tank. <IMAGE>

Description

SPECIFICATION Composite control valve means for operating working machines BACKGROUND OF THE INVENTION This invention relates to composite control valve means for operating a working machine.
There are many working machines, each including a number of elements respectively actuated by piston-cylinder assemblies actuated by pressurized oil or air. For the sake of brevity, such piston-cylinder assembly is hereinafter merely called an actuator. In a large working machine including a large number of actuators, some of them are operated by pressurized oil supplied by one oil pump, while the other actuators are operated by pressurized oil supplied by another oil pump.
In a power shovel, for example, actuators for raising and lowering a boom, for operating a bucket and for running the power shovel in the forward direction are supplied with pressurized oil from one oil pump through composite control valve means, and actuators for swinging the deck about a pin carried by an endless belt type carriage and for running in the opposite direction are supplied with pressurized oil from another oil pump through another composite control valve means. In such a case, for the purpose of rapidly operating the actuator for the boom, etc., both outputs of two oil pumps are often used in common.
One example of a typical prior art composite control valve means is illustrated in Fig. 1, in which first, second and third control valves 2, 3, 4 of a first composite valve means 1 selectively supply pressurized oil from an oil pump 5 to actuators respectively for operating the boom, the arm, the bucket and the running mechanism of a power shovel, not shown. To simplify the drawing, only the boom actuator 7 is shown.
The first to fourth control valves 9, 10, 11 and 1 2 of a second composite valve means 2 selectively supply pressurized oil from another oil pump 1 3 to actuators respectively operating running mechanism, the swinging mechanism, the bucket supporting arm, and the boom of the power shovel. The oil pressures of the outputs of the oil pumps 5 and 1 3 are limited by relief valves 1 4. When the control valves are maintained at their neutral positions, the outputs of both pumps are discharged to a drain tank 1 5 through bypass passages extending through the central portions of respective control valves.When a spool, not shown, of the control valve 2 is raised, the pressurized oil is supplied to the rod (upper) side of the actuator 7 from the pump 5, whereas when the spool of the control valve 2 is lowered, the pressurized oil is supplied to head (lower) side, thus reciprocating a piston rod for raising and lowering the boom, not shown. The other control valves operate in the same manner to operate respective actuators.
With the composite control valve means described above, the operating force required to simultaneously switching two control valves 2 and 1 2 for operating the actuator 7 is doubled. In addition, it is necessary to provide a link mechanism, not shown, for simultaneously switching two control valves, thus complicating the mechanism and increasing the space. Moreover, the second composite control valve means comprises four control valves, which also increases the cost and space.
SUMMARY OF THE INVENTION Accordingly, it is an object of this invention to provide an improved composite control valve means capable of simplifying the mechanism and reducing the manufacturing cost and space.
According to this invention, there is provided a composite control valve means for operating at least one actuator of a working machine of the type comprising a pair of oil pumps; and at least two composite valve means connected between the oil pumps and the actuator; each composite valve means including a plurality of control valves, characterized in that there are provided a selector valve integral with one control valve of one composite valve means, the selector valve being operated by the one control valve for controlling communication between a pilot passage and a drain tank, a check valve connected between one side of the actuator and a bypass passage of the other composite valve means, and a logic valve responsive to pressure in the pilot passage for controlling communication between the bypass passage and the drain tank.
BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings: Figure 1 is a diagrammatic representation of a prior art composite control valve means; Figure 2 is a diagrammatic representation of a preferred embodiment of this invention; and Figure 3 is a view similar to Fig. 2 but showing a modified embodiment of this invention.
DESCRIPTION OF THE PREFERRED EMBODI MENTS Fig. 2 shows a preferred embodiment of this invention, in which elements corresponding to those shown in Fig. 1 are designated by the same reference numerals. This embodiment is different from the prior art composite control valve means shown in Fig. 1 in that a selector valve 22 is integrally mounted on one end of the first control valve 22 of a first composite control valve means 21 for establishing or interrupting communication be tween a pilot passage 24 and the drain tank 1 5. The selector valve 23 is provided with a spool, not shown, interlocked with the spool, not shown, of the first control valve 22.A second composite valve means 25 is different from the composite valve means 8 shown in Fig. 1 in that the fourth control valve 1 2 is omitted and that a logic valve 27 is provided having a pilot chamber 27A and connected between a bypass passage 26A and the pilot passage 24. This logic valve 27 interconnects the bypass passage 26A and a conduit 28 connected to the drain tank 1 5 when the pilot chamber 27A, that is the pilot passage 24 is communicated with the drain tank 1 5 through the selector valve 23, whereas interrupts the communication between the bypass passage 26A and the pilot passage 24 when the latter is interrupted from the tank 1 5 so as to create a pressure in the bypass passage 26A.The lower or head side of the boom actuator 7 is connected to the end of the bypass passage 26A where it is connected to the inlet port of the logic valve 27 via a check valve 29.
The composite valve means of this invention operates as follows. In a state shown in Fig. 2, pumps 5 and 1 3 are unloaded because their outputs are drained into the drain tank 1 5 via bypass passages 26A and 26B.
When the spool of the control valve 22 is raised, the pressurized oil outputted by the pump 5 would be admitted into the upper side of the actuator 7 via the control valve 22 to lower the piston 7A of the actuator 7, while the oil in the lower side thereof is discharged to the drain tank 1 5 through the control valve 22. At this time, since the selector valve 23 communicates the pilot passage 24 with the drain tank 15, the pressurized oil outputted by the pump 1 3 is drained into the drain tank through the logic valve 27 so that the pump 1 3 is unloaded. As a consequence, only the pressurized oil outputted by the pump 5 would be supplied to the actuator 7.
When the spool of the control valve 22 is lowered, the output of the pump 5 is admitted into the head or lower side of the actuator 7 to raise its piston rod 7A, while the oil in the upper or rod side is discharged into the drain tank 1 5 via the control valve 22. At this time, since the spool of the selector valve 23 is also lowered, the communication between the pilot passage 24 and the drain tank 1 5 is interrupted so that the piston of the logic valve 27 is moved to the left by a spring to interrupt the communication between the bypass passage 26A and the conduit 28, that is, the tank 1 8. Consequently, oil pressure builds up in the bypass passage 26A so that the pressurized oil flows into the head side of the boom actuator 7 via the check valve 29.
Thus, outputs of both oil pumps 5 and 1 3 are supplied to the boom actuator 7.
Although in the foregoing description, the outputs of both oil pumps are used to raise the piston of the boom actuator 7, if the valve apparatus is constructed such that the communication between the pilot passage 24 and the drain tank 1 5 is interrupted and that the bypass passage 26A of the second composite valve means 25 is connected to the rod or upper side of the actuator via a check valve, not shown, when the spool of the selector valve 23 is raised, the outputs of both oil pumps are supplied to raise and lower the piston rod of the actuator 7.
Fig. 3 shows a modified embodiment of this invention which is similar to the first embodiment except that the check valve 29 is connected to a different point of the second composite control valve means 25. More particularly, in this modification, one side of the check valve 29 is connected to the lower side of the actuator 7, but the other side of the check valve is connected to the inlet side of the bypass passage 26A, that is the inlet side of the control valve 9. When the control valves 9 through 11 of the second control valve means 25 are operated, the upper side of the boom actuator 7 is closed by the control valve 22, so that the actuator 7 would not operate.
Although in the first embodiment shown in Fig. 2, as either one of the control valves 9 through 11 of the second composite valve means 25 is operated, the inlet side of the check valve 29 is interrupted from the pressurized oil circuit, in the second embodiment shown in Fig. 3, since the inlet side of the second control valve means 25 is connected to the inlet side of the check valve 29, even when the second control valve means is operated, the inlet side of the check valve 29 is always connected to the pressurized oil circuit, so that when the control valve 22 of the first composite valve means 21 is operated simultaneously with either one of the control valves 9-11 of the second composite valve means, the boom actuator 7 is operated at the same time as the actuator for operating a swinging mechanism, or a running mechanism or an arm of the power shovel. In other words, the composite valve means establishes parallel circuits for a number of actuators of the power shovel.
As above decribed, according to this invention, in an installation where supply of pressurized oil to one or more actuators of a working machine from two oil pumps is controlled by a pair of composite valve means, a logic valve is arranged between an unloader circuit of one composite valve means and a drain tank, and the logic valve is controlled by a spool valve provided for one control valve of the other composite valve means so that it is possible to supply combined output of two oil pumps to the actuator without using any transfer valve for this purpose. More particularly, according to the prior art construction, it is necessary to provide an additional control valve for the second composite valve means 25. Since the selector valve 23 is small and integral with the control valve 22, and since the logic valve 27 is also small and has a simple construction, it is possible to also supply the output of the oil pump 1 3 with small operating force and without using any interlocking link mechanism.
Although the invention has been described as applied to a power shovel, it should be understood that the invention is also applicable to other types of civil machines, robbot machines or the like utilizing a number of actuators, some of them being of a large capacity and should be simultaneously supplied with the outputs of two or more oil pumps.

Claims (5)

1. Composite control valve means for operating at least one actuator of a working machine, comprising: a pair of oil pumps; at least two composite valve means connected between said oil pumps and said actuator, each composite valve means including a plurality of control valves; a selector valve integral with one control valve of one composite valve means, said selector valve being operated by said one control valve for controlling communication between a pilot passage and a drain tank; a check valve connected between one side of said actuator and a bypass passage of the other composite valve means; and a logic valve responsive to pressure in said pilot passage for controlling communication between said bypass passage and said drain tank.
2. The composite control valve means as defined in claim 1 wherein said bypass passage is connected to said drain tank through a pressure relief valve.
3. The composite control valve means according to claim 1 wherein when said one control valve is in a neutral position, said selector valve connects said pilot passage to said drain tank so that said logic valve operates to connect said bypass passage to said drain tank, whereas when said selector valve is operated together with said control valve, said- pilot passage is interrupted from said drain tank so as to interrupt the communication between said drain tank and said bypass passage thus applying outputs of said pair of oil pumps to said actuator.
4. The composite control valve means according to claim 1 wherein said check valve is connected to one end of said bypass passage close to said logic valve.
5. The composite valve means according to claim 1 wherein said check valve is connected to one end of said bypass passage remote from said logic valve.
GB8126311A 1980-09-08 1981-08-28 Composite control valve means for operating working machines Expired GB2085971B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP55124249A JPS5751006A (en) 1980-09-08 1980-09-08 Composite control valve for conflluence

Publications (2)

Publication Number Publication Date
GB2085971A true GB2085971A (en) 1982-05-06
GB2085971B GB2085971B (en) 1984-01-25

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ID=14880653

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8126311A Expired GB2085971B (en) 1980-09-08 1981-08-28 Composite control valve means for operating working machines

Country Status (4)

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JP (1) JPS5751006A (en)
DE (1) DE3135202A1 (en)
FR (1) FR2489895A1 (en)
GB (1) GB2085971B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58115563U (en) * 1982-01-29 1983-08-06 新キャタピラ−三菱株式会社 Actuator hydraulic control circuit
JPS59186502U (en) * 1983-05-31 1984-12-11 株式会社小松製作所 directional valve
JPS6099303U (en) * 1983-12-12 1985-07-06 カヤバ工業株式会社 confluence circuit

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1250219B (en) * 1967-09-14 Ludwig Rexroth I ohr/M Device for connecting two pumps in parallel
DE1952034A1 (en) * 1969-10-15 1971-04-22 Linde Ag Control device for a hydraulic system and valve for this

Also Published As

Publication number Publication date
FR2489895A1 (en) 1982-03-12
JPS5751006A (en) 1982-03-25
FR2489895B1 (en) 1984-11-23
GB2085971B (en) 1984-01-25
DE3135202A1 (en) 1982-04-15

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 19940828