EP0159949B1 - Steuervorrichtung mit Servo-Ventilen - Google Patents

Steuervorrichtung mit Servo-Ventilen Download PDF

Info

Publication number
EP0159949B1
EP0159949B1 EP85400760A EP85400760A EP0159949B1 EP 0159949 B1 EP0159949 B1 EP 0159949B1 EP 85400760 A EP85400760 A EP 85400760A EP 85400760 A EP85400760 A EP 85400760A EP 0159949 B1 EP0159949 B1 EP 0159949B1
Authority
EP
European Patent Office
Prior art keywords
servo
valve
valves
control
hydraulic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP85400760A
Other languages
English (en)
French (fr)
Other versions
EP0159949A1 (de
Inventor
Jean-Yves Bezard
Jean Marie Brocard
Christian Parisel
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.)
Safran Aircraft Engines SAS
Original Assignee
Societe Nationale dEtude et de Construction de Moteurs dAviation SNECMA
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 Societe Nationale dEtude et de Construction de Moteurs dAviation SNECMA filed Critical Societe Nationale dEtude et de Construction de Moteurs dAviation SNECMA
Publication of EP0159949A1 publication Critical patent/EP0159949A1/de
Application granted granted Critical
Publication of EP0159949B1 publication Critical patent/EP0159949B1/de
Expired legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B18/00—Parallel arrangements of independent servomotor systems
    • 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
    • F15B13/043—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure with electrically-controlled pilot valves
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/86493—Multi-way valve unit
    • Y10T137/86574—Supply and exhaust
    • Y10T137/86582—Pilot-actuated
    • Y10T137/8659—Variable orifice-type modulator
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/86493—Multi-way valve unit
    • Y10T137/86574—Supply and exhaust
    • Y10T137/86582—Pilot-actuated
    • Y10T137/86614—Electric

Definitions

  • the invention relates to the control, by means of servo-valves, of a hydraulically actuated member.
  • a member of this type for example a distributor drawer in the case of a two-stage system, or a jack, a metering device, in the case of a single-stage system, is associated with at least one subject chamber at a servo pressure, controlled by a servo-valve, ensuring its positioning.
  • servo valve control devices comprising a pallet mounted at the end of a rod housed inside a spring tube fixed on a base, supporting at its free end a movable transverse element in the air gap excitation coils; according to the current applied to the coils, the pallet moves between two nozzles connecting each of the organ control chambers at low pressure and thus determines its position.
  • Such devices have the disadvantage of being very sensitive to pollution; this is because of the short stroke of the pallet between the two nozzles which is of the order of only a few hundredths of a millimeter. If, in fact, a particle of this order of magnitude, transported by the servo fluid, is inserted between the nozzle and the pallet, it tends to get caught there and paralyze the pallet in an off-center position.
  • Patent GB-A-1,369,441 clearly shows an electro-hydraulic control system where two servo-valves in parallel receive the same electrical control signals and act simultaneously on the same pressure chambers of an operating member; a device is provided which makes it possible to detect a difference in operation between the two servo-valves and to generate an error signal.
  • US Pat. No. 3,437,312 describes a redundant control system comprising three calculation chains associated with three comparators and two servo-valves, one of the chains being active and the other neutral, the two servos valves being separated by a hydraulic selector which admits on the actuated cylinder sometimes the fluid of the first servo-valve sometimes that of the second.
  • An object of the invention is therefore to provide a hydraulic control device capable of withstanding the first failure of the pilot servo-valve without loss of servo-control.
  • the device for controlling a hydraulically actuated member is of the type comprising a piston movable in a cylinder delimiting at least one chamber subjected to a control pressure signal obtained between a high pressure zone and a low zone pressure by a hydraulic potentiometer constituted by a fixed throttle and a variable-section throttle means, the latter being defined by two electro-hydraulic servo-valves, the device also comprising means for producing the control signals in response to signals of sets so that only one servo valve is pilot, the other remaining neutral, and being capable of reacting to a means of detecting malfunction of the pilot servo valve to switch the command in order to make the servo valve pilot neutral and neutral the pilot servo valve.
  • the servo-valves offer a predetermined passage section in the neutral position and the electrical control signals of the two servo-valves alone ensure the switching of these, the active servo-valve and the servo -Neutral valve cooperating to permanently deliver the servo pressure signal.
  • the servo-valves are of the single-nozzle and vane type which in the neutral position offer a predetermined and adjustable passage section.
  • FIG. 1 there is shown a block diagram of a known embodiment of the control of a dispenser drawer 1 by a servo-valve 2 with pallet 5 and double nozzle 6 and 6 '.
  • the two free ends of the drawer form pistons of equal sections delimiting two chambers 3 and 3 'with the cylinder in which the drawer is housed.
  • These chambers are supplied with fluid by means of a hydraulic potentiometer constituted between a high pressure source HP and a low pressure cover BP by two fixed diaphragms 4 and 4 'in parallel and two nozzles with variable section 6 and 6' each in series with one of the diaphragms 4 and 4 '.
  • the fluid supplying the chambers 3 and 3 ' is taken between a diaphragm and a nozzle so that the pressure prevailing in the chambers is an intermediate pressure between the values of HP and BP.
  • the two nozzles are mounted opposite one another on either side of the movable pallet parallel to their axis so as to reduce, respectively increase the flow section of the fluid towards the low pressure; thus a differential pressure is created between the chambers 3 and 3 'causing the slide to move.
  • the pallet 5 is integral with a rod 7 mounted inside a flexible tube 8 made of a non-magnetic spring metal of small thickness.
  • the tube is secured to the support, not shown, by its base. It also supports a movable soft iron bar 9 inside the excitation coils B1, B2. Thus, depending on the excitation current, the pallet moves in one direction or the other or is brought back to an intermediate position by the spring tube 8.
  • a device like this has the disadvantage of being very sensitive to pollution because the distance separating the nozzles is very small, of the order of only a few hundredths of a millimeter.
  • a simple particle inserted between a nozzle and the pallet blocks any movement of the latter and renders the entire control inoperative.
  • a second cause of failure is the rupture of the spring tube due to its great fragility due to the small thickness of the wall.
  • Figure 2 shows a diagram of a first embodiment.
  • a distributor drawer terminated by two pistons with differential sections; this drawer itself controls the supply of working fluid to a jack driving a body to be positioned.
  • the invention also applies to the control of a single-stage system such as a metering device or a jack or any other member with equivalent operation.
  • no mechanical return of the slide position is shown, it is always possible to introduce counter-force springs in the control chambers.
  • Bedroom. 16 the section of which is the smallest, communicates directly with the source of fluid 18 at a pressure maintained constant by a pressure regulator.
  • each pallet 21, 31 now controls the passage section of a single nozzle 22, 32 and its opening movement is limited by a mechanical stop 23, 33.
  • the position of the stop is adjusted so that the pallet is tangent to it under the action of the spring tube only, in the absence of excitation current from the torque motor, thus determining a maximum passage cross section.
  • the constituent elements are dimensioned so that in the event of a rupture of the spring tube, the pallet also comes to bear against the stop.
  • the winding of the torque motor of each of the servo valves is connected to an electronic control system 100.
  • This system is designed to control only one of the two servo valves at a time leaving the other at rest in the full open position. .
  • the pressure inside the chamber 17 is modulated by controlling the section of the single nozzle 22 for example, the nozzle 32 delivering a constant and predetermined leak rate.
  • the servo valve can no longer perform its function; the controlled member moves away from its set position whatever the order given to the servo-valve.
  • FIG. 3 shows a nonlimiting example of an electronic control system capable of ensuring this switching function in the event of a fault.
  • the control system comprises two entirely separate electrical lines 200, 300 each comprising inputs 201, 301 respectively for the setpoint signals, an electronic circuit 202, 302 and a line connected to the winding of the torque motor of the corresponding servo-valve 20, 30. Each of the lines also receives the position detector signals from the controlled member 203, 204 and 303, 304.
  • Each circuit includes two computers identical, 205. 206 for circuit 202 and 305, 306 for circuit 302, defining the position to be reached according to the data received in 201 and 301.
  • the 1st computer 205, 305 is used for the command, it provides a signal which is compared at 211, 311 respectively to a signal corresponding to the actual position of the body, produced by the first detector 203, 303; the difference value signal is amplified in an amplifier 207, 307, the output of which is connected to the winding of the corresponding torque motor by means of a switch 208, 308: the latter reacts to a signal supplied by an adder amplifier 209 , 309 which comprises as input the output signal of the amplifier 309, 209 from the other line and the signal corresponding to the difference value, produced at 210 and 310 between the set value calculated by the second computer 206, 306 and the value of the position of the controlled body supplied by a second detector 204, 304.
  • each of the lines receives the same input signals and produces identical control signals: but in normal operation, the switch 208 is closed, and the switch 308, the control of which is reversed with respect to 208 , is open so that only the servo valve connected to the first line is pilot, the other remaining neutral. in the open position. If a failure occurs, the difference signal between the value calculated by 206 respectively 306 and the value provided by 204 respectively 304 increases until it exceeds a predetermined threshold. Then the amplifiers 209 and 309 produce control signals which will reverse the position of the switches 308 and 208 respectively.
  • the servo-valve 20 no longer supplied, becomes neutral and the pallet is brought into abutment against the mechanical stop.
  • the servo valve 30, in turn, becomes pilot.
  • the switching from one line to the other is bi-stable so that the command does not switch back to the 1st line when the deviation signal returns to a value below the triggering threshold of the circuits 209, 309.
  • the switching relates only to the electric control signals of the two servo-valves, these contributing together permanently to supply the control pressure signal.
  • This electronic control circuit is given only by way of example. Instead of a redundant system, it is possible to design a single line with signal switching on the second servo valve in the event of a malfunction if the servo valves are less reliable. than electronics.
  • FIG. 4 shows an alternative mounting of the two servo valves applying the same principle of the invention.
  • the references have been assigned a premium sign.
  • the servo valves are no longer mounted in parallel but in series.
  • the control fluid flows from the pressure HP to the pressure BP in a circuit comprising in series the fixed diaphragm 19 ', the first servo-valve 30' and the second servo-valve 20 '; chamber 17 'of the distributor communicates with the circuit, between 19' and 20 '.
  • the pressure in this chamber is controlled by the single servo valve 20 '.
  • an electro-hydraulic control device is produced which tolerates the first pollution failure or the first mechanical failure of the vibrating tube rupture type, while retaining 100% of the capacity of the device.
  • This device is at the same time simple, the redundancy is achieved by retaining the same number of nozzles as a usual servo-valve, it does not require a hydraulic switching slide, the latter being obtained electrically by opening the switch. of the electrical control circuit of one of the servo-valves and the simultaneous closing of the corresponding switch of the other circuit.
  • This device is self-repairing to a certain extent.
  • the invention although this has not been described on a drawing board, can also be applied to the redundant control of double-acting cylinders using for the control of each enclosure of the cylinder a set of two servo-valves arranged according to the invention, in series or in parallel.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Servomotors (AREA)
  • Fluid-Pressure Circuits (AREA)

Claims (5)

1. Steuervorrichtung für ein hydraulisch betätigtes Organ mit einem Kolben (15, 15'), der in einem Zylinder bewegbar ist, der wenigstens eine Kammer begrenzt, die einem Nachführungsdrucksignal ausgesetzt ist, das zwischen einer Hochdruckzone und einer Niederdruckzone mit Hilfe eines hydraulischen Potentiometers gewonnen wird, das aus einer festen Drosselvorrichtung (19, 19') und einer Drosselvorrichtung mit variablem Querschnitt besteht, wobei letztere von zwei elektrohydraulischen Servoventilen (20, 30; 20', 30') gebildet ist, sowie mit einer Einrichtung (100 ; 100') zur Erzeugung von Steuersignalen in Abhängigkeit von Befehlssignalen derart, daß jeweils nur eines der Servoventile das steuernde Ventil bildet, während das andere neutral bleibt, wobei diese Einrichtung auf eine Einrichtung zur Detektion einer Fehlfunktion des als steuerndes Ventil wirksamen Servoventils reagiert, um die Steuerung derart umzuschalten, daß das neutrale Servoventil zum steuernden Ventil wird und das steuernde Ventil zum neutralen Ventil, dadurch gekennzeichnet, daß die Servoventile (20, 30 ; 20', 30') in neutraler Position einen vorbestimmten Durchgangsquerschnitt haben, und daß die elektrischen Steuersignale der beiden Servoventile nur deren Umschalten sicherstellen, wobei das aktive Servoventil und das neutrale Servoventil zusammenwirken, um ständig das Servodrucksignal zu liefern.
2. Steuervorrichtung für ein hydraulisch betätigtes Organ nach Anspruch 1, dadurch gekennzeichnet, daß die Servoventile (20, 30) hydraulisch parallel geschaltet sind.
3. Steuervorrichtung für ein hydraulisch betätigtes Organ nach Anspruch 1, dadurch gekennzeichnet, daß die Servoventile (20', 30') hydraulisch in Reihe geschaltet sind.
4. Steuervorrichtung für ein hydraulisch betätigtes Organ nach einem der Ansprüche 2 oder 3. dadurch gekennzeichnet, daß die Servoventile solche mit einer Einfachdüse (22, 32 : 22', 32') und einem Anker (21, 31 : 21', 31') sind und daß der Anker in neutraler Position in eine vorbekannte und regelbare Position zurückgestellt ist.
5. Steuervorrichtung für ein hydraulisch betätigtes Organ nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die Einrichtung zur Erzeugung der Steuersignale zwei unabhängige elektronische Schaltungen aufweist, die jeweils über einen Schalter (208, 308) mit einem Servoventil verbunden sind, wobei dieser Schalter in Abhängigkeit vom Auftreten eines Fehlers in einem der elektrohydraulischen Kreise gesteuert werden.
EP85400760A 1984-04-18 1985-04-17 Steuervorrichtung mit Servo-Ventilen Expired EP0159949B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8406099A FR2563289B1 (fr) 1984-04-18 1984-04-18 Dispositif de commande a servo-valves
FR8406099 1984-04-18

Publications (2)

Publication Number Publication Date
EP0159949A1 EP0159949A1 (de) 1985-10-30
EP0159949B1 true EP0159949B1 (de) 1987-12-23

Family

ID=9303255

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85400760A Expired EP0159949B1 (de) 1984-04-18 1985-04-17 Steuervorrichtung mit Servo-Ventilen

Country Status (4)

Country Link
US (1) US4561470A (de)
EP (1) EP0159949B1 (de)
DE (1) DE3561256D1 (de)
FR (1) FR2563289B1 (de)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4953578A (en) * 1989-11-02 1990-09-04 Johnson Service Company Dual mode pneumatic control system
USRE34202E (en) * 1989-11-02 1993-03-30 Johnson Service Company Dual mode pneumatic control system
US9459630B2 (en) 2013-10-22 2016-10-04 Fisher Controls International Llc System and method for controlling a remote valve
CN113431820B (zh) * 2021-06-17 2024-01-30 浙江中控技术股份有限公司 一种支持在线更换的冗余伺服控制系统及方法

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1369441A (en) * 1970-12-11 1974-10-09 Dowty Boulton Paul Ltd Electro-hydraulic control system

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3055383A (en) * 1955-11-01 1962-09-25 Ii William A Paine Electro-hydraulic servo systems
US3018794A (en) * 1959-03-31 1962-01-30 Clark Controller Co Valves and safety controls therefor
US3257911A (en) * 1963-08-15 1966-06-28 Moog Inc Fluid powered servomechanism of a redundant, majority voting type
US3437312A (en) * 1966-11-01 1969-04-08 Bell Aerospace Corp Electrical signal and monitoring apparatus for redundant control system
US3494256A (en) * 1968-07-01 1970-02-10 Bendix Corp Dual redundant electrohydraulic servo system
BE789975A (fr) * 1971-10-12 1973-02-01 Sanders Associates Inc Valve de controle de pression et de debit
FR2178356A5 (de) * 1972-03-29 1973-11-09 Sopelem
DD136524A5 (de) * 1977-12-16 1979-07-11 Technomatic Ag Sicherheitsventil
DE2931533C2 (de) * 1979-08-03 1984-09-13 Messerschmitt-Bölkow-Blohm GmbH, 8000 München Servosteuersystem
GB2103388B (en) * 1981-08-08 1985-06-26 Moog Inc Servovalves

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1369441A (en) * 1970-12-11 1974-10-09 Dowty Boulton Paul Ltd Electro-hydraulic control system

Also Published As

Publication number Publication date
FR2563289A1 (fr) 1985-10-25
EP0159949A1 (de) 1985-10-30
FR2563289B1 (fr) 1988-08-26
DE3561256D1 (en) 1988-02-04
US4561470A (en) 1985-12-31

Similar Documents

Publication Publication Date Title
CA2382809C (fr) Systeme d'actionnement hydraulique a commande electrique
EP0639499B1 (de) Servosteuerungvorrichtung eines Steuerwerkes eines Flugzeuges
EP0159949B1 (de) Steuervorrichtung mit Servo-Ventilen
EP1342645B1 (de) Hydraulische Lenkvorrichtung
FR2466650A1 (fr) Dispositif de commande actionne par pression
FR2466649A1 (fr) Dispositif pour regler un organe variable, en particulier, le mecanisme de levage d'un tracteur
EP0500419B1 (de) Proportionales Wegeventil und Steuersystem für mehrere hydraulische Verbrauchen, wobei jeder solch ein Ventil beinhaltet
FR2621354A1 (fr) Dispositif de commande independant de la charge pour appareils utilisateurs hydrauliques
FR3051026A1 (fr) Servovalve a actionneur piezo electrique redondant asymetrique.
FR2662753A1 (fr) Dispositif de commande d'un verin hydraulique a double effet.
EP1688625B1 (de) Steueranordnung für eine Mehrzahl von Entlastungsventilen einer Turbomaschine
EP0278814B1 (de) Kraftstoffregler für Turbomaschinen
FR2721070A1 (fr) Dispositif de surveillance et de détection automatique d'anomalies fonctionnelles sur un circuit d'alimentation en pression d'une pompe principale.
FR2813926A1 (fr) Dispositif hydraulique a soupapes
FR2695861A1 (fr) Dispositif hydraulique sensible de sélection de vitesse et de puissance adapté sur un système de commande synchrone de vérins multiples de presse.
FR2611001A1 (fr) Dispositif de commande electrohydraulique pour commander un element d'entrainement hydraulique, notamment un verin de presse
EP0192547B1 (de) Betätigungseinrichtung für Doppelhauptbremszylinder
EP0465279B1 (de) Steuereinrichtung für einen Arbeitszylinder
FR2555775A1 (fr) Dispositif d'actionnement de deux soupapes pouvant etre actionnees en interdependance
FR2589416A1 (fr) Generateur de pression de freinage
FR2462599A1 (fr) Systeme de servocommande, en particulier pour aeronef ou astronef
EP0262007A1 (de) Durchflusskontrolle-Nachlaufeinrichtung für hydraulische Anlage, insbesondere für Kraftfahrzeug-Servolenkung
FR2751601A1 (fr) Actionneur hydromecanique
FR2462583A1 (fr) Systeme d'entrainement hydrostatique
FR2573169A1 (fr) Appareil de positionnement a distance d'une valve

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19850502

AK Designated contracting states

Designated state(s): DE FR GB

17Q First examination report despatched

Effective date: 19870506

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB

REF Corresponds to:

Ref document number: 3561256

Country of ref document: DE

Date of ref document: 19880204

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
REG Reference to a national code

Ref country code: FR

Ref legal event code: CL

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19920320

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19920327

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19920630

Year of fee payment: 8

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19930417

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19930417

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19931229

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19940101

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST