US3252381A - Rapid response hydraulic system - Google Patents

Rapid response hydraulic system Download PDF

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Publication number
US3252381A
US3252381A US323791A US32379163A US3252381A US 3252381 A US3252381 A US 3252381A US 323791 A US323791 A US 323791A US 32379163 A US32379163 A US 32379163A US 3252381 A US3252381 A US 3252381A
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Prior art keywords
hydraulic
fluid
control valve
motor means
auxiliary reservoir
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Expired - Lifetime
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US323791A
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English (en)
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Gratzmuller Jean Louis
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    • 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
    • F15B1/024—Installations or systems with accumulators used as a supplementary power source, e.g. to store energy in idle periods to balance pump load
    • 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
    • F15B11/08—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor
    • 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
    • F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/04—Special measures taken in connection with the properties of the fluid
    • F15B21/044—Removal or measurement of undissolved gas, e.g. de-aeration, venting or bleeding
    • 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
    • F15B2211/30—Directional control
    • F15B2211/315—Directional control characterised by the connections of the valve or valves in the circuit
    • F15B2211/3157—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line
    • F15B2211/31582—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line having multiple pressure sources and a single 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
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/61—Secondary circuits
    • F15B2211/613—Feeding circuits
    • 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
    • F15B2211/655—Methods of contamination control, i.e. methods of control of the cleanliness of circuit components or of the pressure fluid

Definitions

  • This invention relates to hydraulic systems for controlling the operation of a hydraulic motor means such as a hydraulic jack. More particularly, the invention is concerned with such a system wherein the operation response time is controlled and made as rapid as possible whereby the system can be efficiently used to operate a separate element such as, for example, an electric circuit breaker.
  • the present invention is directed providing a system which is free of the aforesaid disadvantages, which permits difierent vertical locations of system components, which incorporates an auxiliary reservoir means thereby eliminating the requirement for massive conduits, and which further insures complete system operation free of entrapped air or gas therein.
  • the present invention is directed to the provision of a hydraulic system incorporating a hydraulic motor means, a comparatively high volume hydraulic power circuit for operating the hydraulic motor means and a comparatively low volume hydraulic control circuit for controlling the operation of the hydraulic motor means by the hydraulic power circuit, (a) which system is so constructed and arranged as to be free of entrapped air therein, and (b) which system provides 3,2523% Patented May 24, 1966 for rapid response times and permits substantially identical repeating operations.
  • the invention contemplates utilizing an auxiliary low pressure reservoir for receiving fluid discharged from the hydraulic motor means during deactivation thereof, which reservoir is so located and coupled in the system that, once the system has started satisfactory operation, air cannot pass to the motor means or into the portion of the system coupling the reservoir with the motor means, notwithstanding the fact that system deactivation-is achieved by venting to the atmosphere. Still further, in this regard, the invention contemplates utilizing (l) a hydraulically' actuated control valve means which selectively controls the feed of the powering hydraulic fluid into and out of the motor means, and (2) a hydraulic control. circuit which operates the control valve means, but
  • the aforesaid auxiliary reservoir is positioned above the highest level of hydraulic fluid within the hydraulic motor means.
  • the control valve means serves to selectively couple the hydraulic motor means either with the auxiliary reservoir or a source of fluid under pressure.
  • the control valve means is itself, as indicated, preferably hydraulically operated and coupled in a control circuit having parallel branches leading from a system distributor means which is located below the control valve means and below the auxiliary reservoir.
  • the distributor means can be positioned at some remote location with respect to the motor means and the control valve means, and in any event is below such means.
  • One of the parallel branches in the control circuit has a one-way valve therein permitting the flow of fluid from the branch only in the direction to the distributor, thereby providing for the purge of any air trapped in the control circuit.
  • FIGURE 1 presents a schematic side view of a hydraulic system constructed in accordance with the present invention
  • FIGURE 2 is a transverse sectional view of a control valve means which can be utilized in the system of FIGURE 1;
  • FIGURE 3 is a schematic side view of a fragment of the system of FIGURE 1, FIGURE 3 presenting modified control arrangement which can be utilized in accordance with the invention in the basic system of FIGURE 1;
  • FIGURE 4 is a schematic view of a hydraulic system controlling a plurality of hydraulic motor means.
  • the system includes a hydraulic motor means 4 in the form of a hydraulic jack.
  • a hydraulic motor means 4 in the form of a hydraulic jack.
  • Such jack comprises a housing 4a having a piston 5 reciprocably moveable therein.
  • a piston rod 6 Extending upwardly from the piston 5 is a piston rod 6 which, with reciprocal movement of the piston 5, serves to control a circuit breaker St
  • the circuit breaker St is but illustrative of one type of device which may be contolled through movement, of the piston rod 6.
  • the invention finds particular utility when employed for the control of the circuit breaker.
  • the particular mechanical connection (not shown) hetween the piston rod 6 and the device which is operated by movement of such piston rod can be conventional.
  • the invention is not concerned with the particular mechanical link utilized for coupling the motor means 4 with the device to be operated by the system, and accordingly, suflice it to say, that the motor means 4 is adapted to operate some other device, such as the circuit breaker 50.
  • the hydraulic motor means 4 comprises part of a hydraulic circuit including a source of hydraulic fluid under pressure and an auxiliary reservoir.
  • the source of hydraulic fluid under pressure comprises an accumulator 2 for supplying hydraulic fluid under a pressure within a given range.
  • the auxiliary reservoir 8 takes the form of a tank which is preferably vented to the atmosphere as by a vent tube 8a.
  • the auxiliary reservoir 8 could be under some pressure interiorly, and the important factor is that the pressure in the auxiliary reservoir is less than the pressure of the fluid supplied from the accumulator 2.
  • a conduit 12 serves to connect the accumulator 2 with a control valve means 10, and similarly a conduit 16 serves to connect the auxiliary reservoir 8 with the control valve means 10.
  • Such valve means is provided to permit selective coupling of the hydraulic motor means 4 alternately with the accumulator 2 and the auxiliary reservoir 8.
  • a coupling conduit 14 leads from the uppermost portion of the housing 4a of the jack to the control valve means It i
  • the control valve means 10, as shown, is hydraulically actuated, but the same may take various forms. Regardless of the particular control valve means used, it is operative in one position or condition to supply fluid under pressure from the accumulator 2 through the conduit 12 and into the conduit 14.
  • the fluid When in such position or condition, the fluid reacts against the piston 5, thereby causing such piston to move vertically downward, as shown.
  • the piston 5 preferably reacts during this travel against a means for normally urging the piston to an upper position, such means taking the form, for example, of the spring 7 shown in FIGURE 1.
  • This spring is compressed between the lower face of the piston 5 and the bottom wall of the housing 4a when the fluid under pressure is causing the piston 5 to move downwardly.
  • the lower position of the piston 5 can well be the activating position thereof when the same is coupled with a separate device, such as the circuit breaker 50. Assuming this to be true, then at some time, it would be desired to rapidly deactivate the separate device, and in turn to permit the piston 5 to return to its upper position or deactivated position. To achieve this result, the control valve means 10 is operated to a second position or condition where it dis-establishes or interrupts communication between the conduits 12 and 14, but at the same time establishes communication between the conduits 14 and 16. At this time, under the action of the spring 7, the piston 5 is'urged upwardly, forcing hydraulic fluid thereabove to flow from the housing 4a into the conduit 14, through the control valve 10 and the conduit 16 into the auxiliary reservoir 8.
  • the auxiliary reservoir 8 is dimensioned so as to easily receive the discharged fluid from the housing 4a, and moreover, since the auxiliary reservoir 8 is vented to the atmosphere, the force exerted by the spring 7 on the piston 5 to discharge the fluid is minimized.
  • the auxiliary reservoir 8 has a drain conduit 24 leading from the lower portion thereof and extending to a sump or main reservoir 20.
  • the conduit 24 does not connect with the lowermost level of the auxiliary reservoir 8, but instead is preferably positioned .such that it communicates with the auxiliary reservoir slightly above the lowest level therein.
  • Conduit 24 permits discharged fluid to drain from the auxiliary reservoir 8 and to the sump or main reservoir 20 but, as should be apparent, the auxiliary reservoir 8 never becomes completely empty 4.- since the conduit 24 does not communicate with the lowest level thereof.
  • auxiliary reservoir 8 is positioned above the highest level of fluid in the hydraulic motor means 4, and (2) that the control valve means 10 is positioned below the lowest level of fluid in the auxiliary reservoir and preferably adjacent the jack or motor means 4.
  • the sump or main reservoir 20 referred to above has a line 21 leading therefrom and to the conduit 12 or essentially the accumulator 2.
  • a pump 22 is connected in such conduit so that hydraulic fluid can be returned from the sump 20 under the proper pressure to the hydraulic power circuit referred to above.
  • a line 19 leads from the sump to a distributor means 18 which takes the form of a conventional three-way valve.
  • This valve is movable to alternately connect a hydraulic control circuit with the accumulator 2 as by the line 23, or with the sump 20 as by the line 19.
  • the distributor means 18 is part of the distributor or control circuit which operates with minor fluid flow as compared to the power circuit.
  • the distributor or control circuit includes a pair of parallel conduits or circuit branches 30 and 32 which feed to a common output branch 31.
  • the output branch 31 feeds into the control valve means 10.
  • the control valve means can take various forms, and can include, as shown in FIGURE 1, a cylinder 25 connected to branch 31, with a piston 26 slidably mounted in the cylinder upon a piston rod 28 which connects to the control valve means 10,
  • the control valve means 10 preferably takes the form of the valve means shown in FIGURE 2 and described more fully below.
  • the distributor circuit or control circuit includes two branches, one of which, namely the branch 32, has a one-way valve 34 therein, which valve permits the fluid in the distributor circuit to flow only toward the distributor means 18 as shown by the arrows adjacent the branches 30 and 32.
  • the hydraulic control valve means shown therein includes a housing a having a plurality of passageways 12, 14', 16' and 31' corresponding to the conduits 12, 14, 16 and 31 to which they are respectively coupled.
  • the passageway 31 leads to a lower internal chamber 31a which communicates with respective piston chambers housing a piston 26a and a piston 38.
  • the piston 26a is coupled by a shaft 28a to an input valve control member 36.
  • the same reacts on the piston 26a thereby lifting the valve member 36 to permit fluid to flow through the passageway 12' and into the passageway 14'.
  • the pressure in the lower chamber 31a of the valve means It forces the piston 38 upwardly thereby blocking the passageway 16'. Still, the fluid can flow around the plug end 38a of the piston 38 which blocks the passageway 16.
  • valve member 36 moves downwardly under the action of its associated biasing spring 37 and closes communication between the passageway 12' and the passageway 14' by blocking the valve seat 36a.
  • the piston 5 is urged upwardly by its biasing spring 7 and the fluid in the housing 4a is forced through the conduit 14 into the passageway 14'.
  • This fluid reacts on the piston 26a to maintain the valve member 36 seated on the valve seat 36a, but at the same time reacts against the piston 38 to displace the same downwardly, compressing the biasing spring 39 for piston 38 and opening communication between the passageway 14' and the passageway 16'.
  • the pressure face of the piston 26a in the chamber 27 is greater than the pressure face of the valve member 36 in such chamber, and that the valve member 36 has openings 36a therein which permit the fluid under pressure in the passageway 12' travelling from the accumulator 2 to equalize on opposite sides of the pressure face of the valve member 36, thereby permitting the control referred to above without interference from the power fluid under pressure.
  • FIGURE 2 Although the arrangement of FIGURE 2 is simple and accordingly desirable for use in the system of FIGURE 1, a pair of control valves can be used as the control valve means 10.
  • a pair of control valves l0 and 10" are shown as being coupled in the distributor or control circuit by means of the respective output lines 31 and 31". These output lines are connected with the branch lines 30 and 32, and the respective valves 10 and MD are conventional valves. These valves work oppositely with one valve 10' assuming an open position when there is pressure on the fluid in the control circuit and with the other valve 10 assuming an open position when the pressure on the fluid in the control circuit is reduced.
  • the operation of the valves 10 and 10" corresponds to the operation of the control valve means 10 described above, and accordingly further description of this modification appears unnecessary.
  • a jack forms the preferred hydraulic motor means utilized in accordance with the invention
  • other motor means can be incorporated in the system.
  • same need not take the exact form shown in the drawings, and can be reversed in so far as movement is connected.
  • the system is readily adapted to provide rapid response control for a hydraulic motor means disposed at an upper convenient vertical level with the basic control or distributor located at some lower vertical level and in a remote position with respect to the motor means and the control valve and auxiliary reservoir associated therewith.
  • FIGURE 1 While the invention has been shown in FIGURE 1 and described above as including a single motor means, the system is readily adapted to operate a plurality of motor means, for instance two hydraulic jacks 44, as shown on FIGURE 4.
  • a group of control valves 1010' would be utilized and coupled in parallel to the line or conduit 12.
  • a separate auxiliary reservoir 8-8' would be incorporated for each motor means with the return line from each auxiliary reservoir draining to the sump or main reservoir 20.
  • a single distributor means 18 can be used for common operation of the various motor means.
  • the multiple motor means system can be operated from the same source of hydraulic fluid under pressure (preferably a hydro-pneumatic accumulator 2) notwithstanding the separate auxiliary reservoir associated with each individual motor means.
  • a hydraulic system of the type including a hydraulic circuit having therein hydraulic motor means, a source of hydraulic fluid under pressure within a given range, a main reservoir positioned below the lowest level of fluid in said motor means, an auxiliary reservoir under a pressure less than the pressures within said given range and communicating with said main reservoir and hydraulically actuated control means for selectively coupling said hydraulic motor means alternatively with said source of hydraulic fluid and said auxiliary reservoir, the improvement comprising:
  • a distributor circuit including distributor means positioned below said hydraulic motor means for selectively coupling said control valve means with said source of hydraulic fluid to actuate said control valve means
  • control valve means being positioned above said distributor means and below the lowest level of fluid in said auxiliary reservoir, whereby said hydraulic motor means, said control valve means and the portion of said hydraulic circuit between said auxiliary reservoir and said control valve means remain filled with hydraulic fluid regardless of the selective coupling of said motor means with said auxiliary reservoir and said source of hydraulic fluid.
  • said distributor circuit includes a pair of parallel branches, one of which branches has a one-way valve therein for permitting the flow of liquid within said one branch only toward said distributor means.
  • auxiliary reservoir has an output line leading to said main reservoir, said output line being in communication with said auxiliary reservoir above the lowest level therein.
  • said hydnaulically actuated control means comprises a pair of hydraulically operated valves coupled in said distributor circuit for common operation by said distributor means.
  • a hydraulic system comprising a plurality of hydraulic motor means, fluid supply means for delivering hydraulic fluid under pressure within a given range, a plurality of reservoirs under pressures less than the pressures within said given range, said reservoirs each being coupled respectively with a different one of said hydraulic motor means, said reservoirs being positioned above the highest level of fluid respectively in the hydraulic motor means with which said reservoirs are respectively coupled, control valve means for selectively coupling said hydraulic motor means with said fluid supply means and said reservoirs, hydraulic control circuit means coupled with said control valve means and including distributor means positioned below said hydraulic motor means and said reservoirs for selectively actuating said control valve means.
  • a hydraulic system including a hydraulic jack having a hydraulic fluid inlet in the upper portion thereof, a circuit breaker operated by said jack, a source of hydraulic fluid under pressure, an auxiliary low pressure reservoir positioned above said fluid inlet in said jack, a main reservoir for receiving fluid from said auxiliary reservoir under gravity flow, hydraulically actuated control valve means positioned above said main reservoir and below said auxiliary reservoir for selectively coupling said jack alternatively with said source of hydraulic fluid and said auxiliary reservoir, hydraulic control circuit means coupled to said control valve means and including distributor means positioned below said jack and said control valve means for selectively coupling said control circuit means with said source of hydraulic fluid to actuate said control valve means.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Fluid-Driven Valves (AREA)
  • Auxiliary Drives, Propulsion Controls, And Safety Devices (AREA)
US323791A 1962-11-16 1963-11-14 Rapid response hydraulic system Expired - Lifetime US3252381A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR915617A FR1350707A (fr) 1962-11-16 1962-11-16 Installation de commande hydraulique à réponse rapide

Publications (1)

Publication Number Publication Date
US3252381A true US3252381A (en) 1966-05-24

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US323791A Expired - Lifetime US3252381A (en) 1962-11-16 1963-11-14 Rapid response hydraulic system

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US (1) US3252381A (xx)
AT (1) AT256237B (xx)
CH (1) CH402618A (xx)
DE (1) DE1425786B2 (xx)
ES (1) ES293503A1 (xx)
FR (1) FR1350707A (xx)
GB (1) GB1066590A (xx)
SE (1) SE302408B (xx)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3724333A (en) * 1969-12-04 1973-04-03 Borgs Fabriks Ab Operating system for aircraft barrier nets
US3933338A (en) * 1974-10-21 1976-01-20 Exxon Production Research Company Balanced stem fail-safe valve system
USRE30115E (en) * 1974-10-21 1979-10-16 Exxon Production Research Company Balanced stem fail-safe valve system
US4296910A (en) * 1977-08-29 1981-10-27 Gratzmuller J Hydraulically controlled safety valve
WO2015172981A1 (de) * 2014-05-14 2015-11-19 Robert Bosch Gmbh Hydrauliksystem
US10147980B2 (en) 2014-05-28 2018-12-04 Robert Bosch Gmbh Method for battery management and battery management system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2115506A5 (xx) * 1970-11-23 1972-07-07 Gratzmuller Jean Louis

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2608986A (en) * 1945-07-23 1952-09-02 William T Stephens Fluid flow control valve
US2948262A (en) * 1956-03-02 1960-08-09 Gratzmuller Jean Louis Pressure-limiting device
US2972337A (en) * 1959-11-30 1961-02-21 Gen Electric Hydraulically actuated operating mechanism for an electric circuit breaker
US3119308A (en) * 1961-10-19 1964-01-28 Gen Electric Velocity and rate of change of pressure limiting system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2608986A (en) * 1945-07-23 1952-09-02 William T Stephens Fluid flow control valve
US2948262A (en) * 1956-03-02 1960-08-09 Gratzmuller Jean Louis Pressure-limiting device
US2972337A (en) * 1959-11-30 1961-02-21 Gen Electric Hydraulically actuated operating mechanism for an electric circuit breaker
US3119308A (en) * 1961-10-19 1964-01-28 Gen Electric Velocity and rate of change of pressure limiting system

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3724333A (en) * 1969-12-04 1973-04-03 Borgs Fabriks Ab Operating system for aircraft barrier nets
US3933338A (en) * 1974-10-21 1976-01-20 Exxon Production Research Company Balanced stem fail-safe valve system
USRE30115E (en) * 1974-10-21 1979-10-16 Exxon Production Research Company Balanced stem fail-safe valve system
US4296910A (en) * 1977-08-29 1981-10-27 Gratzmuller J Hydraulically controlled safety valve
WO2015172981A1 (de) * 2014-05-14 2015-11-19 Robert Bosch Gmbh Hydrauliksystem
CN106460874A (zh) * 2014-05-14 2017-02-22 罗伯特·博世有限公司 液压系统
US10147980B2 (en) 2014-05-28 2018-12-04 Robert Bosch Gmbh Method for battery management and battery management system

Also Published As

Publication number Publication date
FR1350707A (fr) 1964-01-31
DE1425786A1 (de) 1969-04-03
ES293503A1 (es) 1964-01-16
DE1425786B2 (de) 1971-02-04
SE302408B (xx) 1968-07-15
AT256237B (de) 1967-08-10
CH402618A (fr) 1965-11-15
GB1066590A (en) 1967-04-26

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