US2938346A - Control devices for hydraulic actuators - Google Patents

Control devices for hydraulic actuators Download PDF

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Publication number
US2938346A
US2938346A US753357A US75335758A US2938346A US 2938346 A US2938346 A US 2938346A US 753357 A US753357 A US 753357A US 75335758 A US75335758 A US 75335758A US 2938346 A US2938346 A US 2938346A
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United States
Prior art keywords
valve
pressure
chamber
actuator
piston
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Expired - Lifetime
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US753357A
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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
    • 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
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • F15B13/0401—Valve members; Fluid interconnections therefor
    • F15B13/0405—Valve members; Fluid interconnections therefor for seat valves, i.e. poppet valves
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/02—Details
    • H01H33/28—Power arrangements internal to the switch for operating the driving mechanism
    • H01H33/30—Power arrangements internal to the switch for operating the driving mechanism using fluid actuator
    • H01H33/34—Power arrangements internal to the switch for operating the driving mechanism using fluid actuator hydraulic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/02—Details
    • H01H33/28—Power arrangements internal to the switch for operating the driving mechanism
    • H01H33/30—Power arrangements internal to the switch for operating the driving mechanism using fluid actuator
    • H01H2033/308—Power arrangements internal to the switch for operating the driving mechanism using fluid actuator comprising control and pilot valves

Definitions

  • this invention relates to devices for controlling the connection of a single acting hydraulic jack or like actuator'to a hydraulic pressure source and to an exhaust respectively.
  • the connection is effected 'so that both the power and return strokes of the actuator (the latter being effected by continuously acting biasing means, e.g. a spring or weight)- can be initiated by a triggering action and thereafter completed automatically.
  • biasing means e.g. a spring or weight
  • Devices of this kind are especially adapted for controlling an hydraulic actuator which operates an electrical circuit-breaker meeting certain requirements.
  • an hydraulic actuator which operates an electrical circuit-breaker meeting certain requirements.
  • the opening movement must be effected as rapidly as possible to facilitate arc-quenching, and consequently it is usual for the opening movement to be performed by the return stroke of the actuator.
  • the permanent bias means effects the return stroke of the actuator by exerting a very strong effort, provision being made for exhausting the actuator extremely rapidly.
  • a control device of the kind above defined is described in the United States Patent 2,900,960 for Hydraulic Control Device and fulfils the requirement of positively holding the actuator by continued application of the supply pressure in the terminal position of its power stroke.
  • vibrations and chattering may occur at the beginning of the power stroke of the actuator. This is particularly the situation if the triggering action, by which the power stroke is initiated, is discontinued before the necessary operative'pressure has been built-up in the service line that feeds the actuator.
  • the main object of this invention is to provide means for eliminating this kind of malfunctioning.
  • a more particular object of this invention is to provide a control device of the type first herein defined which comprises a chamber communicating with the actuator and also communicating through a normally closed main valve with the pressure source and with exhaust through an auxiliary valve, which, when closed, positively opens the main valve.
  • means are provided for continuously applying the pressure in the chamber to the auxiliary valve in the sense to close it, the auxiliary valve being also subjected when closed to the same pressure, but with consid-. erably reduced effort, in the sense to open it.
  • a first triggering valve is provided for temporarily applying the 7 2,938,346 Patented May 31, 1960 and a calibrated restrictor is provided which is operative between the chamber andthe actuator.
  • This invention relates to control devices for hydraulic Y pressure of the source to the auxiliary valve in'the sense 5 auxiliary valve to initiate opening thereof when closed,
  • the power stroke is triggered by opening the first triggering valve to close the auxiliary valve and open the main valve.
  • the closing pressure on the auxiliary valve is that in the intermediate chamber and is supplied from the pressure source through the main valve.
  • this closing pressure is less than the supply pressure owing to the pressure-drop through the main valve. If the intermediate chamber were in free communication with the actuator, then this pressure-drop would account for substantially the whole of the difference between the supply pressure and the pressure in the actuator.
  • the pressure downstream of the main valve in the intermediate chamber might not be sufiicient to maintain complete closure of the auxiliary valve and opening of the main valve, with the result that vibrations and chattering of the valves would occur.
  • the calibrated restrictor is preferably bypassed by a duct containing a non-return valve allowing flow in the exhausting direction only.
  • This by-pass duct may contain a second calibrated restrictor, whose sole function is to stabilize the exhaust flow.
  • control 'device is unitary with a pressure source and an exhaust reservoir '4.
  • the pre's sure source is an hydropneurnatic accumulator-1 having a floating piston 2 separating the liquid spaceabove the piston from the penumatic pressure space'lt el'ow itQ T
  • he control device itself comprises a body 25 on to the base of which the accumulator 1 is screwed and" on top. of which is mounted a casing, the interior of whichf'fo'rms the exhaust reservoir 4*. Chambersii and 31in the body 'termediate chamber 35.
  • Chambers"3j1 and '21 respectively are closed from above by sub-'bodies'12 and 27 which are detachably fixed in the main body 25; and other sub-bodies 24 and one enhaust stroke of the controlled actuator 40.
  • the main admission valve 6 is closed, the auxiliary valve 8 is open closing a chamber 37 are likewise detachably fixed in body 25.
  • Theactuator 40 to be controlled is provided with a single service line 42 which enters the body 25 at'a service line opening 3,
  • the main'admission valve constituted by a cone 6 lightly pressed towards its seating by a spring 7, controls seatable on the opening connecting chambers 35 and 39.
  • the piston is lightly spring loaded as shown in the :sense to unseatlthe valve member 8.
  • .Ports 11 provide communication between the portion of chamber 39 below the piston 10 and the exhaust reservoir 4.
  • the auxiliary valve member 8 is ,seatable to close the auxiliary valve and open the main admission valve 6 .by admitting hydraulic pressure to a chamber 14 above the piston v10.
  • Chamber .14 communicates, via a side pipe, with chamber 37.
  • the first triggering valve housed in subbody 27, is constituted by a ball lightly .springloaded towards its seating, which, when unseated, affords communication between chamber 21 and chamber 37, through a non-return'ball valve 22 .Ball 20 is unseatable by depressing an external push-button 17 against the elic t of a lightspring, .a loose push-rod .19 being interposed between the button 17 and the ball 20.
  • .ball 20 When .ball 20 is unseated, the supply ,pressureof accumulator ,1 is transmitted, via the opening 29, passage 33, chamber21 and non-return valve 22 to thecharnber .14, causing piston 10 to be depressed to close the auxiliary valve 8 and open the main valve 6, a
  • ball 16 is unseated chamber 14 communicates, via aside port 18 in sub-body 12 with the exhaust reservoir:4.
  • the intermediate chamber 35 communicates with the serviceline opening 3 through a calibrated restrictor R located in a side port of sub-body '24.
  • Theservice line opening 3 also communicates, through-a second calibrated restrictor r7,.1ocated in a :by-pass duct formed .in sub-body 24 and containing .a-nonvreturn' ball valve 23, with-the .in-
  • the non-return valve23 closes the ,by-pass duct against ilowlin the admission sense .indicatedby thelower arrow .to .the left of the service. line opening .3 while allowing how. in .the exhausting ,sense indicated by the upper arrow.
  • the .detachabilityffof lsubihody 24 enables the restrictors R and r to be exchanged .jfor .others having .different ratings without difiiculty.
  • the intermediate chamber 35 being in communication via valve 8 with the chamber 3,? below the piston, is at exhaustpressure andso is :the chamber 1 ⁇ above the piston owing to the intercommunication of chambers 14 and via chamber 37 and the restrictor 13 through which there is no flow, and consequently nopressure-drop, the piston 10 beingstatio nary. :Both facesuof piston 10 are therefore subjected .tothe exhaust pressure acting over equal areasand consequently valve 8 is held open by its spring. The device therefore remains in the normal position until thefirst triggering valve ball 20 is unseated by depressing the push-button 1.7.
  • the restrictor 13 impedes flow of liquid from the chamber 37 to the intermediate chamber 35 and thus ensures that there is very little loss of pressurehetween the chamber 21, which is at the full supply pressure, and chamber 14. If the rcstrictor 13 were not there, the liquid flow through valve 22 would be by passed'direct to exhaust through the intermediate chamber '35 and piston ,10 would not be displaced.
  • the pressure in cham- The drawing shows .thecontr olcdevicein the .normal her '35 is also applied directly to valve member .8 in the sense to open it; but since the area of piston 10 is intentionally made considerably greater than, and preferably about four times as great as, that of the seating of the valve member 8, the valve-closing effort of this pressure is predominant and the valve 8 will remain positively closed, provided the pressure in the intermediate chamber 35 is :sufiicient to'be effective.
  • valve 6 opens and admits liquid from the accumulator 1, via chamber 31, into the intermediate chamber 35 and thence into the service line 42 of the actuator 40, via opening 3.
  • the pressure-drop across the valve 6 only accounts :for part of the difiference between the supply pressure and that in the service line, which is initially at exhaust pressure; and consequently, from the instant at which the valve 6 opens, a positive pressure is established in the intermediate chamber 35, however low may be the pressure in'the service line.
  • the restrictor R is preferably calibrated to produce a pressure-drop equal to that across the valve 6 when fully open, in which case the pressure in the intermediate chamber '35,from the-instant at which valve '6 opens, can never be less than half the supply pressurerand this is adequate toensure that'the valves remains closed and the valve 6' open,-provided the net area of piston 10 (i e. its'total .area' less that of theseating of valve 8) is not too'sma'll.
  • valve 6 stays open and the actuator remains in its end of power stroke" position, until the push-button 15 is depressed to unseat the ball 16 and vent the chamber 14 to exhaust, while the restrictor 13 momentarily delays the concurrent release of pressure in the intermediate chamber 35, thus assisting the rapid opening of valve 8 and closure of valve 6.
  • valve 3 must stay open as previously stated. This allows actuator to be exhausted freely through both restrictors R and r, flow through the latter in this direction being permitted by the non-return valve 23. This completes the operative cycle of the device, the actuator remaining in the end of return stroke position until push-button 17 is again depressed.
  • Hydraulic control device for selectively controlling the connection of an hydraulic service line serving a single-acting hydraulic actuator to a hydraulic pressuresource and exhaust respectively comprising a valve chamber connected to the service line, a normally closed main valve controlling communication between the pressuresource and said chamber, a normally open auxiliary valve controlling communication between said chamber and exhaust, means actuated by said auxiliary valve to open positively said main valve when said auxiliary valve closes, said auxiliary valve being subjected when closed to the pressure in said chamber acting in the sense to open the auxiliary valve, a single-acting hydraulic cylinder and piston operative to close said auxiliary valve, said piston having a greater area than that on which the pressure in said chamber is exerted in the sense to open the auxiliary valve, a passage connecting said chamber to said cylinder, a restrictor in said passage, a first triggering valve for temporarily connecting said cylinder to said pressuresource, a non-return valve between said first triggering valve and said cylinder for preventing flow from said cylinder to said first triggering valve, a second triggering valve for temporarily connecting
  • Hydraulic control device for selectively connecting an hydraulic service line serving an hydraulic actuator, such as a single-acting jack, to a source of hydraulic pressure and to exhaust respectively, such device com prising a valve chamber connected to the service line, a main valve controlling communication between the pressure source and said chamber and normally held closed by the pressure of said source, an auxiliary valve controlling communication between said chamber and exhaust and subjected when closed to the pressure in said chamber acting in the sense to open it, a singleacting hydraulic jack operative to close the auxiliary valve and open the main valve, the piston area of said jack being considerably greater than the area of the auxiliary valve on which the pressure in said chamber acts, a duct interconnecting said chamber with said jack, a restrictor in said duct, a normally closed triggering valve controlling direct communication between said jack and exhaust, another normally closed triggering valve controlling direct communication between the pressure source and said jack, a non-return valve preventing flow from said jack to said other triggering valve, and a calibrated restrictor through which said chamber communicates with
  • Device as defined in claim 2 including a bypass duct connecting said chamber to the service line and a non-return valve in said by-pass duct preventing bypass flow from said chamber to the service line.
  • Device as defined in claim 3 including further a calibrated restrictor in said by-pass duct.
  • a hydro-pneumatic accumulator constituting the pressuresourceand an exhaust reservoir, said device, said accumulator and said reservoir being assembled as a unitary structure.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)
  • Servomotors (AREA)
  • Valve Device For Special Equipments (AREA)
US753357A 1957-08-12 1958-08-05 Control devices for hydraulic actuators Expired - Lifetime US2938346A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR745358 1957-08-12

Publications (1)

Publication Number Publication Date
US2938346A true US2938346A (en) 1960-05-31

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US753357A Expired - Lifetime US2938346A (en) 1957-08-12 1958-08-05 Control devices for hydraulic actuators

Country Status (6)

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US (1) US2938346A (fr)
CH (1) CH348323A (fr)
DE (1) DE1293035B (fr)
FR (1) FR1181089A (fr)
GB (1) GB828597A (fr)
NL (1) NL108019C (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3225662A (en) * 1960-08-26 1965-12-28 Miehle Goss Dexter Inc Submerged servomotor with prefill valve for guillotine type paper cutting machine
US3486417A (en) * 1968-03-04 1969-12-30 Int Harvester Co Seat suspension assembly
US3893374A (en) * 1973-07-04 1975-07-08 Hitachi Ltd Circuit breaker operating device
US4075839A (en) * 1975-10-07 1978-02-28 Patent Products Hydraulics (Proprietary) Limited Decompression of pressure chambers, particularly the decompression of actuating pressure chambers of mine cage holding means
US4184334A (en) * 1978-09-11 1980-01-22 International Harvester Company Closed center draft control valve
US4475710A (en) * 1980-05-22 1984-10-09 Kraftwerk Union Aktiengesellschaft Electro-hydraulic control actuator for turbine valves
US6000687A (en) * 1998-11-19 1999-12-14 Hydra-Lock Corporation Actuator for hydraulic tool holder
CN104822949A (zh) * 2012-10-19 2015-08-05 土耳其赫马公司 带有流量分配器的防止受压油泄漏到控制阀汽缸管的系统

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3263469D1 (en) * 1981-03-26 1985-06-20 Bbc Brown Boveri & Cie Hydraulic or pneumatic control

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE594222C (de) * 1932-10-23 1934-03-14 Cie Internationale Des Freins Hydraulische Treibvorrichtung, insbesondere zum Bewegen von Bremsen und Tueren von Fahrzeugen
US1961465A (en) * 1933-10-21 1934-06-05 Swanson & Thompson Control device for lifts
FR1145495A (fr) * 1956-03-02 1957-10-25 Dispositif limiteur de pression

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE519002A (fr) * 1952-04-05

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE594222C (de) * 1932-10-23 1934-03-14 Cie Internationale Des Freins Hydraulische Treibvorrichtung, insbesondere zum Bewegen von Bremsen und Tueren von Fahrzeugen
US1961465A (en) * 1933-10-21 1934-06-05 Swanson & Thompson Control device for lifts
FR1145495A (fr) * 1956-03-02 1957-10-25 Dispositif limiteur de pression

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3225662A (en) * 1960-08-26 1965-12-28 Miehle Goss Dexter Inc Submerged servomotor with prefill valve for guillotine type paper cutting machine
US3486417A (en) * 1968-03-04 1969-12-30 Int Harvester Co Seat suspension assembly
US3893374A (en) * 1973-07-04 1975-07-08 Hitachi Ltd Circuit breaker operating device
US4075839A (en) * 1975-10-07 1978-02-28 Patent Products Hydraulics (Proprietary) Limited Decompression of pressure chambers, particularly the decompression of actuating pressure chambers of mine cage holding means
US4184334A (en) * 1978-09-11 1980-01-22 International Harvester Company Closed center draft control valve
WO1980000606A1 (fr) * 1978-09-11 1980-04-03 Int Harvester Co Vanne de commande d'ecoulement a centrage ferme
US4475710A (en) * 1980-05-22 1984-10-09 Kraftwerk Union Aktiengesellschaft Electro-hydraulic control actuator for turbine valves
US6000687A (en) * 1998-11-19 1999-12-14 Hydra-Lock Corporation Actuator for hydraulic tool holder
CN104822949A (zh) * 2012-10-19 2015-08-05 土耳其赫马公司 带有流量分配器的防止受压油泄漏到控制阀汽缸管的系统
CN104822949B (zh) * 2012-10-19 2016-08-17 土耳其赫马公司 带有流量分配器的防止受压油泄漏到控制阀汽缸管的系统

Also Published As

Publication number Publication date
DE1293035B (de) 1969-04-17
NL108019C (fr) 1964-04-15
CH348323A (fr) 1960-08-15
GB828597A (en) 1960-02-17
FR1181089A (fr) 1959-06-11

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