EP0039247A2 - Hydraulisches Steuersystem - Google Patents

Hydraulisches Steuersystem Download PDF

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Publication number
EP0039247A2
EP0039247A2 EP81301900A EP81301900A EP0039247A2 EP 0039247 A2 EP0039247 A2 EP 0039247A2 EP 81301900 A EP81301900 A EP 81301900A EP 81301900 A EP81301900 A EP 81301900A EP 0039247 A2 EP0039247 A2 EP 0039247A2
Authority
EP
European Patent Office
Prior art keywords
valve
actuator
control system
working fluid
pressure
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.)
Withdrawn
Application number
EP81301900A
Other languages
English (en)
French (fr)
Other versions
EP0039247A3 (de
Inventor
John Lawrence Evans
Richard Thomas Entwistle
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.)
Chubb Fire Ltd
Original Assignee
Chubb Fire Security Ltd
Chubb Fire 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 Chubb Fire Security Ltd, Chubb Fire Ltd filed Critical Chubb Fire Security Ltd
Publication of EP0039247A2 publication Critical patent/EP0039247A2/de
Publication of EP0039247A3 publication Critical patent/EP0039247A3/de
Withdrawn legal-status Critical Current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
    • 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
    • F15B13/042—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure
    • A—HUMAN NECESSITIES
    • A62—LIFE-SAVING; FIRE-FIGHTING
    • A62C—FIRE-FIGHTING
    • A62C31/00—Delivery of fire-extinguishing material
    • A62C31/02—Nozzles specially adapted for fire-extinguishing
    • A62C31/24—Nozzles specially adapted for fire-extinguishing attached to ladders, poles, towers, or other structures with or without rotary heads
    • 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

Definitions

  • the present invention relates to hydraulic control systems.
  • a fire fighting monitor comprises a nozzle borne by a mechanism which permits the orientation of the nozzle to be adjusted by pivotal movements about two orthogonal axes - a generally vertical axis about which the nozzle can be pivoted to traverse its jet from side to side, and a generally horizontal axis about which the nozzle can be pivoted to adjust its angular elevation or depression.
  • Such devices may be embodied as portable free-standing units to be set up as required at the scene of afire, or may be mounted on trailers or self-propelled fire fighting vehicles, or may be used in fixed installations at tanker jetties, oil refineries or other fire risk areas. Similar devices also find application in certain forms of mining and industrial washing processes.
  • a drawback of pneumatic control is that by virtue of the inherent compressibility of the medium involved there is an inevitable lag, and subsequent over-reaction, in the response of the pneumatically operated actuators employed, which increases as the distance between the pressure source and responding mechanism increases, and makes precise control over the orientation of the nozzle difficult to achieve. Accordingly we consider the most favourable solution to be an hydraulic control system, such a system having the advantage that both power and control signals can be transmitted by a medium which is inherently safe and relatively incompressible. In other respects, too, an hydraulic system is eminently suited to operation under the harsh conditions to be expected in fire fighting.
  • one of the aims of the invention is to provide a control system which can employ pressurised water as a working fluid to power actuators for adjusting the orientation of the nozzle of a monitor.
  • the water pumps commonly available on fire appliances typically operate in the region of 80 or 100 psig (5-7 bar), which is adequate for the task of driving mechanical actuators for the nozzle-orienting mechanism of a monitor.
  • Another aim of the invention is to provide a control system which can employ relatively long lengths of small-bore flexible plastics tubing to transmit hydraulic pressure signals from a remote operator's pontrol station to pilot-operate control valves associated with the device to be controlled.
  • a tubing length of 50 metres is envisaged.
  • tubing has many advantages, particularly in relation to portable fire fighting monitors intended to be carried as part of the equipment of a fire appliance or other vehicle and to be set up as required at the scene of a fire - the tubing can be reeled for storage between use and readily deployed in use to link the monitor to a safe, remote control station, the tubing being run around corners or over obstacles as required to permit optimum siting of both the monitor and the control station. In one sense, however, the inherent elasticity of such tubing poses problems.
  • curve Cl in Figure 1 of the accompanying drawings indicates a typical form of pressure characteristic which is exhibited at one end of an initially unpressurised, fluid-filled length of flexible plastics tubing when a guage pressure of p 1 is applied to the other end (substantially instantaneously) at time T o . It is assumed that the compressibility of the fluid itself is negligible and that the elastic limit of the tubing is not exceeded.
  • a pressure P I of 800 psig (55 bar) upon the application of a pressure P I of 800 psig (55 bar) to the other end the time (T 1 - T ) taken for the pressure at the said one end to rise to this value is in the region of a second.
  • Curve C2 indicates the corresponding pressure characteristic at one end of the tubing when initially pressurised to P 1 and then, at time T 2' the gauge pressure at the other end is (substantially instantaneously) relieved to zero.
  • the time (T 3 - T 2 ) taken for the pressure at the said one end to decay fully from 800 psig (55 bar) to zero is also in the region of a second (although the two periods (T 1 - T 0 ) and ( T 3 - T 2 ) are not necessarily equal in all cases).
  • the curve C2 (or the relevant part of it) is applicable to the decay of pressure whatever its initial value.
  • P 2 represents a pressure of 100 psig (7 bar)
  • the time (T 3 - T S ) taken for this pressure to decay at the said one end is just over one half of the time (T 3 - T 2 ) taken for the pressure to decay from P 1 .
  • any remote control system it is, of course, a requirement that the device to be controlled has an adequately rapid response to transmitted control signals if precise control is to be achieved and problems of over- and under- control avoided.
  • some delay and possibly over-reaction in the initiation of a movement can be tolerated provided, however, that once initiated the rate of movement can be brought rapidly under control and, most importantly, that movement can be terminated rapidly when the nozzle reaches a desired position.
  • hydraulic pressure signals are transmitted to pilot-operated control valves by tubing having the characteristics indicated in Figure 1, therefore, it is desirable for the valves to have an. operational pressure or range (i.e.
  • the present invention resides in an hydraulic control system for a mechanical device, comprising: at least one actuator adapted to perform a function in relation to the mechanical device under the action of a pressurised hydraulic working fluid; at least one pilot-operated control valve associated with the mechanical device for controlling the supply of said working fluid to said actuator in a manner determined by the pressure of an hydraulic signal fluid transmitted thereto; means, intended to be located remote from the device, for generating signal pressures in said signal fluid in response to an operator's control; and conduit means for transmitting signal pressures from said generating means to said control valve; the arrangement being such that, in use, the signal pressure or range of signal pressures to which said control valve responds is or are of a greater value than the working pressure at which said working fluid is supplied to that valve.
  • such a system is particularly applicable to the control of a fire fighting or the like monitor where the working fluid is water and said conduit means comprise a length of small-bore flexible plastics tubing.
  • the bore of such tubing may be no more than, say 5 mm,preferably less than 2.5mm.
  • the invention can, however, equally by applied to the remote control of other devices, e.g. cranes and the like article-handling equipment, and with other working fluids if desired.
  • the conduit means by which pressure signals are transmitted comprise flexible plastics tubing.
  • the invention may also be found useful where pressure signals are transmitted through conventional steel pipework or other conduit means which can normally be regarded as 'rigid' (i.e.
  • Control System especially adapted for use with a fire fighting monitor, there are a pair of double-acting actuators for controlling the elevation/depression and traverse positions of the monitor nozzle, respectively, and four pilot-operated control valves each one for controlling the supply of working fluid to a respective side of a respective actuator, there being a correspondong number of conduits for transmitting signal pressures from the generating means to the valves.
  • Each such valve is biased into a position in which it can communicate the source of working fluid with the respective side of the respective actuator, and each valve is operable independently,against its bias, in response to the transmission thereto of a selected signal pressure or range of signal pressures, to restrict the communcation of the source of working fluid with the respective side of the respective actuator and to communicate that side of that actuator with a relatively unpressurised reservoir, drain or the like region whereby a pressure differential is set up across the actuator under which it performs the corresponding function in relation to the monitor.
  • a preferred form of pilot-operated control valve usable in a system as defined above comprises: means defining a chamber; first, second and third ports opening to said chamber; first and second valve seats respectively surrounding said first and second ports; first and second valve elements disposed in said chamber for co-operation respectively with said first and second seats to control fluid flow through said first and second ports; first and second spring means for biasing respectively said first and second valve elements against said first and second seats; means for unseating said first valve element against the bias of said first spring means in response to a selected signal pressure or range of signal pressures; and means for establishing an operative connection between said first and second valve elements when said second valve element moves away from said second seat against the bias of said second spring means by a certain distance, whereby when such connection is established the operation of said unseating means is effective both to move said first valve element away from said first seat and to move said second valve element back towards said second seat.
  • said first port is connected to the aforesaid drain or other relatively unpressurised region
  • said second port is connected to the source of pressurised working fluid
  • said third port is connected to the respective side of an actuator.
  • the second valve element is seated under the bias of its spring means so as to isolate the third port and actuator from the relatively unpressurised region.
  • the second valve element can, however, be unseated by the working fluid against the bias of its spring means in the manner of a non-return valve, the working fluid thus being supplied through the chamber and third port to the actuator.
  • the unseating means (which in this case may comprise, e.g. a slidable piston to one side of which the signal pressure is applied) the first valve element is unseated to communicate the actuator with the relatively unpressurised region while the second valve element, through the aforesaid operative connection with the first valve element, is moved towards its seat to restrict the communication of the source of working fluid with the actuator.
  • a portable, ground- standing fire fighting monitor 1 which in the illustrated example is of the spherical head type and which in particular may be constructed as described in our copending United Kingdom patent application no. 8107483.
  • this monitor comprises a head 2 which carries a nozzle via an outlet fitting 3 and which is borne in a housing 4 for pivotal movement about a horizontal axis so as to adjust the angular elevation or depression of_the nozzle.
  • the assembly of the head 2 and housing 4 is also rotatable as a whole about a vertical axis so as to traverse the nozzle from side to side, to this end the assembly being fast on the upper end of a hollow vertical axle (not shown) which is borne rotatably in the lower body 5 of the monitor and which also serves to lead water to the head 2 from main water inlets 6 in each side of the body 5.
  • a handle-bar 7 is provided
  • the hydraulic control system includes a pair of water- driven double-acting, rotary-output actuators 8 and 9 mounted to the monitor, one each for controlling the horizontal axis and vertical axis movements of the monitor nozzle.
  • the output member of the actuator 8 drives an extension of the axle (not shown) by which the head 2 is pivoted in the housing 4, while the output member of the actuator 9 drives a ring gear (not shown) within the body 5 which is keyed to the vertical axle which bears the housing 4/head 2 assembly.
  • These actuators are connected to a valve block 10 at the rear of the monitor by means of suitable pipework, elements of which are indicated at 11 in Figure 2, and a water supply to the valve block is provided by a pipe 12 fed from the inlets 6.
  • each actuator 8,9 has a pair of ports 8A, 8B and 9A, 9B opening to chambers either side of a movable piston 8C, 9C whereby pressure differences between the ports in each pair result in movement of the respective piston which drives a sector gear (not shown) to give a rotary output to move the monitor nozzle in a corresponding sense.
  • the valve block 10 is also seen to include four identical three-port pilot-operated control valves 13, 14, 15 and 16.
  • One port of each control valve, designated by the suffix A, incorporates a respective check valve element 17 and is connected to a common inlet 18.
  • this inlet is supplied from the pipe 12 of Figure 2 with pressurised water at, say, 80 or 100 psig (5-7 bar), which is provided to the monitor from a suitable appliance-mounted pump.
  • a second port of each control valve, designated by the suffix B, is connected to a common drain 19 from the valve block.
  • the third port of each control valve, designated by the suffix C, is connected to a respective port 8A or 8 B , 9A or 9B of a respective actuator.
  • a five-port manually operable valve 20 (the control member of which is seen at 21 in Figure 2), the purpose of which will be described hereinafter.
  • each actuator port 8A, 8B, 9A and 9B is connected to a respective port 20A, 20B, 20D or 20E of the valve 20.
  • each port of the valve 20 is disconnected from all of the others and in this condition, therefore, the existence of the valve 20 has no effect upon the rest of the hydraulic system.
  • each control valve 13 - 16 comprises a movable valve member biased into one limiting position by a spring. In this position the valve is effective to communicate its 'A' port with its 'C' port but to blank its 'C' port from its 'B' port. While each valve remains in this position, it follows that water from inlet 18 is supplied past the check valve elements 17 to each of the actuator ports 8A, 8B and 9A, 9B, all at the same working pressure, while the drain 19 is isolated from each of these ports.
  • each actuator piston 8C, 9C is hydraulically locked in position and, in the event that an unbalanced, external load is applied to the monitor, tending to displace the piston of either actuator from its set position, and thereby to displace water from one side of the actuator back through the 'C' and 'A' ports of the corresponding control valve, the check valve element 17 of that valve will close to prevent such displacement.
  • one of the valves in the pair 13, 14 or 15, 16 mustbe displaced from its illustrated position, and this can be achieved by the application of a signal fluid pressure in opposition to the bias of the respective valve spring.
  • a pilot system filled with hydraulic oil includes a control unit generally indicated at 22 in Figure 3, which in use is positioned at a location remote from the monitor, so that the monitor can be positioned close to the fire while the operating personnel are permitted to be stationed a safe distance away.
  • the control unit includes a manually operable signal generator 23, which may comprise e.g. a hand lever working a piston in a cylinder filled with the hydraulic oil.
  • a manual selector valve 24 Connected to the generator is a manual selector valve 24 whereby the generated pressure signals can be transmitted to a selected one of four separate hydraulic outlets 25A - 25D in the control unit.
  • a preferred form of combined signal generator and selector valve for use as the unit 22 is described in our co-pending United Kingdom patent application no. 8107484.
  • the block 10 includes four separate hydraulic lines 26A - 26D which lead respectively to the control valves 13 - 16, and the respective outlets 25 and lines 26 are connected together by four individual small-bore thermoplastics hoses 27A - 27D made up into a flexible, 50 metre long loom 28.
  • the loom 28 is normally stored on a reel 29 which houses also the control unit 22, and which is carried together with the monitor 1 to the scene of the fire.
  • the operator After setting up the monitor and connecting its water supply, the operator detaches the reel 29 and retreats with it to a safe distance while the loom 28 unwinds; the control unit 22 is withdrawn from the reel at the selected remote location, and the operator is now ready to assume control of the movements of the monitor nozzle.
  • the hoses 27 may each comprise a length of plain 3.175 mm nominal outside diameter 2.375 mm nominal inside diameter tubing made from nylon 12, e.g. TECALAN (Trade Mark) TTR-L tubing as manufactured by the Plastics Division of Tecalemit (Engineering) Limited.
  • TECALAN Trade Mark
  • the selector valve 24 is shown as connecting the signal generator 23 with outlet 25C. Consequently in this condition pressure signals generated by an operator manipulating the lever of generator 23 are transmitted to outlet 25C and then through hose 27C and line 26C to the movable valve member of control valve 16.
  • the bias of the spring acting on the valve member will be overcome and the valve member will be displaced from its illustrated position.
  • port 16C in the limiting position of the valve member opposite to that in which it is shown it will communicate port 16C with port 16B while port 16A is blanked off from port 16C. In intermediate positions the communication between ports 16A and 16C progressively decreases while the communication between ports 16C and 16B progressively increases.
  • control valves 13 - 16 In order for the operator to exert precise control over the positioning of the monitor nozzle it is most desirable, as previously explained, for the control valves 13 - 16 to react rapidly to the operator's manipulations of the signal generator 23, especially in the sense of termination of the movement of the nozzle. To an extent, also as previously explained, this requirement conflicts with the desirability of using long lengths of flexible plastics hose in the transmission of the pressure signals from generator 23 to the control valves because such hose exhibits certain elasticity effects as its internal pressure is varied.
  • valves 13 - 16 Various forms of pilot-operated control valve suitable for use as the valves 13 - 16 are possible, it being appreciated that the desired pressure response of the valve will depend upon the characteristics of the valve biasing spring and the effective area of the movable valve member which is exposed to the signal pressure.
  • a preferred form of valve is shown in Figure 4 and will now be more fully described with reference to that Figure.
  • FIG. 4 shows a pair of control valves, say valves 13 and 14 of the system described above, incorporated in the valve block 10.
  • the valve pair 15 and 16 will be similar.
  • Each valve has a compound valve member comprising a piston 30 slidably sealed in a bore 31; a first ball 32 in a chamber 33 and urged by a spring 34 against a seat 35, to control communication through the respective valve port 13B, 14B between the chamber 33 and bore 31; and a second ball 36 urged by a spring 37 against a seat 38, to control communication through the respective valve port 13A, 14A between the chamber 33 and a bore 40.
  • the spring 37 acts between the ball 36 and the ball 32 via a spacer 41, and is lighter than the main valve biasing spring 34.
  • each chamber 33 between the seats 35 and 38 Opening from each chamber 33 between the seats 35 and 38 are the respective valve ports 13C and 14C which connect through respective bores 42 to the ports 8A, 8B of the actuator 8.
  • a bore 43 leads to the bore 40 between the two seats 38, and is connected to the source of working fluid, i.e. to the inlet 18.
  • a respective bore 44 leads from the bore 31 of each valve between the seat 35 and piston 30, this constituting the exhaust connection of the respective valve and leading to the drain 19.
  • the respective signal pressure lines 26A and 26B lead to the bores 31 of the valves on the side of the respective piston 30 opposite to the seat 35.
  • FIG. 4 illustrates the valves in the condition which pertains when there is no pressurised working fluid connected to the bore 43 and no signal pressures applied to the lines 26A and 26B, i.e. both balls 32, 36 of each valve are on their respective seats 35, 38.
  • each ball 36 can be displaced from its seat 38 against the biasing action of its spring 37 to seat instead against the spacer 41, thereby opening the chambers 33 to the bore 40 through the respective port 13A, 14A.
  • valve 14 is unaffected and the full water pressure remains applied from its chamber 33 to port 8B of the actuator.
  • the actuator piston 8C therefore moves to the left (in the sense of Figure 4) under the differential pressure at ports 8A and 8B, water draining from the actuator through port 8A and passing through the bore 42, port 13C,chamber 33, port 13B and bore 31 (of valve 13), to the respective bore 44 and drain 19.
  • the signal pressure is released from line 26A the ball 32 of valve 13 is allowed to re-seat under the action of its spring 34, so that the actuator piston 8C is relocked in its new set position.
  • the balls 36 have a non-return function in addition to their function of controlling the water pressure in the respective chamber 33 when a signal pressure is applied to the respective valve, this non-return function being equivalent to that of the check valve elements 17 of Figure 3. That is to say in the event that an unbalanced, external load is applied to the monitor tending to displace the actuator piston 8C from a position in which it has been set, and thereby to displace water from one side of the actuator back through the respective chamber 33 to the bore 40, the corresponding ball 36 will close against its seat 38 to prevent such displacement. In fact, by virtue of the biasing action of its spring 37 each ball 36 will tend to close against its seat 38 whenever the pressure within the corresponding chamber 33 is in balance with the supply pressure in the bore 40.
  • Valve 20 has a further function, which is that it can also connect all of the ports 20A - 20E together to enable the water within the block 10 and actuators 8 and 9 to drain away through drain 19 (the water source being disconnected at this time). Draining the water from the system after use is a useful precaution against corrosion and deposition (particularly bearing in mind that contaminated or seawater, for example, may have been used) and against freezing in cold weather.
  • the actuators 8 and 9 have automatic "snifter" valves, (not shown), which admit air to the system when it is being drained and which also bleed air from the system when it is being filled.
  • the pilot system will not be drained as the same problems of corrosion, deposition or freezing do not arise with its hydraulic fluid. Therefore, when the loom 28 of hoses 27 is reeled between uses it will remain connected to the rest of the pilot.system as indicated in Figure 2, or alternatively valved connectors can be used which retain the hydraulic fluid if the hoses are to be disconnected.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Fire-Extinguishing By Fire Departments, And Fire-Extinguishing Equipment And Control Thereof (AREA)
EP81301900A 1980-04-30 1981-04-30 Hydraulisches Steuersystem Withdrawn EP0039247A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8014216 1980-04-30
GB8014216 1980-04-30

Publications (2)

Publication Number Publication Date
EP0039247A2 true EP0039247A2 (de) 1981-11-04
EP0039247A3 EP0039247A3 (de) 1982-04-28

Family

ID=10513094

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81301900A Withdrawn EP0039247A3 (de) 1980-04-30 1981-04-30 Hydraulisches Steuersystem

Country Status (4)

Country Link
EP (1) EP0039247A3 (de)
AU (1) AU7002081A (de)
GB (1) GB2074759B (de)
ZA (1) ZA812646B (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2517758A1 (fr) * 1981-12-03 1983-06-10 Dubois Ets Dispositif de commande a distance d'une piece de canalisation alimentee par une source de liquide sous pression
FR2541736A1 (fr) * 1983-02-28 1984-08-31 Sundstrand Corp Valve d'etage d'admission a deux elements pour commande hydraulique
CN109248394A (zh) * 2018-10-29 2019-01-22 常熟市名佳电子器材有限公司 温控自动灭火装置

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT402016B (de) * 1995-02-09 1997-01-27 Schmid Karl Hydraulische steuerung für fahrzeuge mit wasser- oder pulverwerfer

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3010519A (en) * 1959-08-31 1961-11-28 Charles S Gillespie Control system for fire nozzles
US3106247A (en) * 1962-03-26 1963-10-08 Lacks Hyman Fire fighting apparatus
DE1918079A1 (de) * 1968-04-10 1969-10-16 Geigy Ag J R Verfahren zur Herstellung von perfluorierten Estern der Fumarsaeure und bestimmten anderen aethylenisch ungesaettigten polybasischen Saeuren sowie deren Polymerisate
DE2149058A1 (de) * 1971-10-01 1973-04-05 Westinghouse Bremsen Und Appba Pneumatische steuereinrichtung fuer verstellschlitten
DE2318272A1 (de) * 1972-04-14 1973-10-31 English Clays Lovering Pochin Hydraulische steuervorrichtung fuer die automatische fernsteuerung eines hydraulischen stellzylinders

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3010519A (en) * 1959-08-31 1961-11-28 Charles S Gillespie Control system for fire nozzles
US3106247A (en) * 1962-03-26 1963-10-08 Lacks Hyman Fire fighting apparatus
DE1918079A1 (de) * 1968-04-10 1969-10-16 Geigy Ag J R Verfahren zur Herstellung von perfluorierten Estern der Fumarsaeure und bestimmten anderen aethylenisch ungesaettigten polybasischen Saeuren sowie deren Polymerisate
DE2149058A1 (de) * 1971-10-01 1973-04-05 Westinghouse Bremsen Und Appba Pneumatische steuereinrichtung fuer verstellschlitten
DE2318272A1 (de) * 1972-04-14 1973-10-31 English Clays Lovering Pochin Hydraulische steuervorrichtung fuer die automatische fernsteuerung eines hydraulischen stellzylinders

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2517758A1 (fr) * 1981-12-03 1983-06-10 Dubois Ets Dispositif de commande a distance d'une piece de canalisation alimentee par une source de liquide sous pression
FR2541736A1 (fr) * 1983-02-28 1984-08-31 Sundstrand Corp Valve d'etage d'admission a deux elements pour commande hydraulique
CN109248394A (zh) * 2018-10-29 2019-01-22 常熟市名佳电子器材有限公司 温控自动灭火装置
CN109248394B (zh) * 2018-10-29 2023-07-04 常熟市名佳电子器材有限公司 温控自动灭火装置

Also Published As

Publication number Publication date
GB2074759A (en) 1981-11-04
ZA812646B (en) 1982-04-28
AU7002081A (en) 1981-11-05
EP0039247A3 (de) 1982-04-28
GB2074759B (en) 1984-02-15

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