EP0084084B1 - Pompe à vide à joint d'huile - Google Patents

Pompe à vide à joint d'huile Download PDF

Info

Publication number
EP0084084B1
EP0084084B1 EP82109588A EP82109588A EP0084084B1 EP 0084084 B1 EP0084084 B1 EP 0084084B1 EP 82109588 A EP82109588 A EP 82109588A EP 82109588 A EP82109588 A EP 82109588A EP 0084084 B1 EP0084084 B1 EP 0084084B1
Authority
EP
European Patent Office
Prior art keywords
oil
pump
line
pressure
vacuum pump
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
EP82109588A
Other languages
German (de)
English (en)
Other versions
EP0084084A1 (fr
Inventor
Hanns-Peter Dr. Berges
Peter Frieden
Wolfgang Leier
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.)
Balzers und Leybold Deutschland Holding AG
Original Assignee
Leybold Heraeus GmbH
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 Leybold Heraeus GmbH filed Critical Leybold Heraeus GmbH
Publication of EP0084084A1 publication Critical patent/EP0084084A1/fr
Application granted granted Critical
Publication of EP0084084B1 publication Critical patent/EP0084084B1/fr
Expired legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C27/00—Sealing arrangements in rotary-piston pumps specially adapted for elastic fluids
    • F04C27/02—Liquid sealing for high-vacuum pumps or for compressors

Definitions

  • the invention relates to an oil-sealed vacuum pump with an oil circuit for supplying the bearings and the pump chamber with oil and an oil circuit valve for shutting off the oil supply to the pump chamber when the pump is at a standstill.
  • An oil-sealed vacuum pump of this type is known from G B-PS No. 875444.
  • the oil pump in the oil circuit sucks the oil from the oil supply in the pump housing and conveys it to a kind of non-return valve, the closing piece of which is under the action of a very weak spring, so that the oil pressure in the oil circuit is only slightly above the ambient pressure. From the valve, which opens against the spring pressure, the excess oil pumped by the oil pump reaches the pump chamber via the bearing of the pump shaft and from there is returned to the oil reservoir via the outlet valve.
  • the disadvantage of this is that no oil can be supplied to the bearings with a pressure that is significantly above the ambient pressure, which is desirable for safe and continuous bearing lubrication.
  • the present invention has for its object to provide an oil-sealed vacuum pump of the type mentioned, in which, despite safe bearing lubrication with pressure oil, pump operation of up to 1000 mbar suction pressure is ensured without unnecessarily loading the pumped gases with oil vapors.
  • the oil circuit serving to supply the bearings of the pump chamber with oil has a pressure stage for reducing the overpressure generated by the oil pump to the ambient pressure and that the branches leading to the bearings - based on the direction of the flowing oil - upstream of the pressure stage and the branch line leading to the pump chamber as well as the shut-off valve behind the pressure stage.
  • the oil pump and the pressure stage can be used to maintain a relatively high pressure in the first part of the oil circuit, from which the bearings are supplied with lubricating oil.
  • the pump room is supplied with pressure-relieved oil, so that the pump works as a self-priming pump.
  • Such a pump sucks little oil at high suction pressures, and a lot of oil at end pressure operation.
  • the increased oil consumption and the disturbing environmental impact at high intake pressures are therefore greatly reduced.
  • the oil supply to the bearings from an oil circuit with a relatively high pressure enables an oil filter to be switched on in this part of the oil line, via which a relatively high pressure difference drops, so that only cleaned oil can be supplied to the bearings. It is also possible to monitor the pump via the oil pressure, which allows a clear statement about the operating state of the pump.
  • the supply of oil to the pump chamber from the subsequent pressure-relieved part of the oil circuit has the advantage that only cleaned oil gets into the pump chamber.
  • the shut-off valve ensures that when the pump is switched off, the amount of oil that remains within the pump chamber is reliably limited. This gives decisive advantages when the pump is cold started, which has a direct influence on the dimensioning of the motor of the pump. An undesirable increase in oil in the pump and in the suction port when the pump is accidentally reversed is also reliably prevented.
  • the oil circuit of the pump is formed by the suction line 11, via which oil is conveyed from the oil reservoir 2 into the oil pressure line 13 by means of the oil pump 12.
  • a throttle 15 is arranged, which ensures the maintenance of the desired oil pressure (between 1.5 and 2, preferably 1.7 bar) and via which the pressure is reduced to the pressure in the oil box 1 .
  • the bearings in the pump are supplied with pressure oil via branches 16, 17, 18.
  • Three oil supply lines 16, 17, 18 are required in the case of a two-stage pump This means that two repositories and one intermediate bearing of the two rotors have to be supplied with oil. In the case of a single-stage pump, two of the three branch lines are sufficient. After flowing through the bearings, the oil that has entered the branch lines 16, 17, 18 returns to the oil reservoir 2.
  • An oil filter 19 is switched into the pressure oil line 13 immediately behind the oil pump 12, so that it is ensured that only cleaned oil flows through the line 13 and through the branch lines connected to it.
  • Another branch line 21 opens into the control cylinder 22, in which the control piston 23 is located.
  • the pressure medium line 24 opens into the cylinder 22, the other end of which is connected to the cylinder 9 on the side of the piston 8 facing away from the valve plate 7.
  • the inlet opening 25 of the pressure medium line 24 in the cylinder 22 is designed as a valve seat.
  • a plug 26 with a sealing bead 27 is inserted into the inlet opening 25.
  • the end face 28 of a cylindrical projection 29 on the control piston 23 with a reduced diameter compared to the control piston serves as the closure member.
  • the control piston 23 is under the action of a spring 31, which is arranged between the control piston 23 and the end wall 32 with the inlet opening 25 of the pressure medium line 24 and is designed as a compression spring.
  • the cylindrical extension 29 can be screwed into the control piston 23 by means of the thread 33, so that the force of the spring 31 acting in the closed state of the control valve 27, 28 can be influenced.
  • a further line 34 opens into the cylinder 22 and is connected to an oil reservoir 35 of small volume which is open at the top.
  • the junction of the line 34 in the cylinder 22 lies on the side of the control piston 23 opposite the junction of the line 21.
  • the oil pump 12 conveys oil from the oil supply 2 into the oil pressure line 13.
  • the oil pump 12 can be designed as a rotary vane pump or gear pump and is coupled in a known manner to the pump shaft as a drive (cf. GB-PS No. 875444).
  • the delivery properties of the pump 12 and the size of the throttle 15 are dimensioned such that the desired oil pressure is built up and maintained in the line 13 after the vacuum pump has started. This pressure acts on the piston 23 and overcomes the force of the spring 31, so that the inlet opening 25 of the pressure medium line 24 is closed.
  • the suction nozzle valve 4 is in its open position, so that the recipient connected to the suction nozzle 3 is evacuated.
  • the pump is switched off, the amount of oil delivered by the oil pump 12 decreases at the same time, so that the oil pressure in the line 13 decreases.
  • the inlet opening 25 is opened so that owing to the atmospheric pressure prevailing on the surface of the oil in the oil reservoir 35, oil is pressed into the pressure medium line 24 and reaches the cylinder 9 under the piston 8.
  • the amount of oil located below the piston 23 and in the oil reservoir 35 is so small that the oil entering the cylinder 9 essentially serves only to seal the piston 8 against its cylinder wall.
  • the actual pressure medium for actuating the piston 8 is the air which, following the oil, passes through the oil supply 35 into the pressure medium line 24.
  • the total amount of oil in the cylinder 22 and in the oil reservoir 35 is a few cubic centimeters. It should be so small that it essentially serves only to seal the gap existing between the piston 8 and the cylinder 9. These processes cause the suction nozzle valve 4 to close without the undesirable air intake. After the suction port valve 4 is closed and the urging air has displaced the oil between the piston 8 and the cylinder wall 9, the pump chamber is ventilated.
  • the function of the intake valve control is independent of the existence of an oil filter 19, i.e. Even in an oil circuit without an oil filter 19 (see line section 20 shown in broken lines), the suction nozzle valve and its control means work perfectly.
  • a particular advantage of the described embodiment of the suction nozzle valve 4 and its control means that work as a function of the oil pressure is that both cylinder / piston devices 8, 9 and 22, 23 are hardly susceptible to tolerances because of the desired gap between the piston and cylinder and therefore without special costs can be produced.
  • the control means can be adjusted in such a way that even with relatively small pressure drops in the oil circuit (for example a drop in the target pressure from approx. 1.7 to 1. 5 bar) the inlet opening 25 of the pressure medium line 24 is released.
  • the response time of the suction nozzle valve 4 is so short that it is ensured that the suction nozzle valve is closed even before the vacuum pump finally runs out.
  • the control of the suction nozzle valve by the oil pressure in an oil circuit has that of an oil arranged on the pump shaft pump is supplied, the advantage of a fast and safe mode of operation, since the operating state of the pump can clearly be derived from the oil pressure in the oil circuit.
  • the outlet opening 14 of the line 13 is assigned a resilient cover 41 which - together with a special design of the wall 42 in the region of the outlet opening 14 - fulfills several functions.
  • the outlet opening 14 is surrounded by a concentric groove 43 in the wall 42 which extends into a bore 44 through which the oil serving to supply the pump chamber passes.
  • This bore is also equipped with a throttle 45, the size of which is adapted to the suction power of the respective pump.
  • the resilient cover 41 which preferably consists of an elastic steel band section, covers both the outlet opening 14 of the oil pressure line 13 and the bore 44.
  • the pressure oil is expanded to the pressure in the oil box as a result of the throttle 15 and initially flows into the groove 43 surrounding the outlet opening 14. Part of the oil flows out of this groove, which is connected to the bore 44, as a result of the Suction effect of the pump chamber through the bore 44 or throttle 45. Excess oil is returned to oil reservoir 2.
  • the resilient cover 41 ensures that only such oil flows through the bore 44 and the throttle 45 that has emerged from the outlet opening 14. Therefore, only oil that has flowed through the oil filter 19 enters the pump chamber.
  • the pump room is therefore no longer affected by dirty oil. Nevertheless, the pump works like a self-priming pump, i.e. it determines the amount of oil it needs itself. In high pressure ranges e.g. Small amounts of oil through the throttle 45 so that undesirably high oil vapor components are not present in the pumped media emerging from the pump. Regardless of this, it is ensured that the bearings are supplied with pressure oil.
  • the resilient cover and the special groove design ensure that the oil is shut off when the pump is not running.
  • the negative pressure acting through the bore 44 in the pump chamber causes the resilient cover to bear tightly against the wall 42.
  • the cover completely blocks the bore 44, so that the oil supply to the vacuum pump is stopped.
  • Fig. 2 shows a rotary vane vacuum pump.
  • the conveyed gases pass through the suction nozzle 3, the open suction nozzle valve 4, via the suction channel 51, which is not visible in the drawing plane and is therefore shown as an arrow, into the pump chamber 52, in which the rotor 53 with the slides 54 is located.
  • the compressed gases pass through the outlet channel 55 into the oil box 1, which is filled with oil up to the line 56, so that the resilient cover 41 lies below the oil level.
  • the actual exhaust pipe is not shown.
  • the end wall 42 of the pump body 57 arranged in the oil box 1 is shown in view in its lower part. 3 and 4 show sections through this end wall at the level of lines 111-111 and IV-IV.
  • the oil pressure line 13 ends with the throttle point 15.
  • the bearing of the pump shaft (not shown) arranged in the end wall 42 is also lubricated via the branch line 17 designed as a bore. This bore is closed to the outside by the plug 58.
  • the resilient cover 41 (shown in broken lines in FIG. 2) is fastened on the end wall 42 by means of the screws 46, 47. It covers the two openings 14 and 44 and the groove 43 surrounding the opening 14.
  • the nozzle 15 is produced by drilling the end wall 42 on both sides.
  • the nozzle 45 is screwed into the end wall 42 by means of a thread 59, so that different nozzles can be used depending on the suction power of the pump.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)

Claims (9)

1. Pompe à vide à étanchéité par l'huile, comportant une circulation d'huile pour alimenter en huile les paliers et le volume de la pompe ainsi qu'une soupape, disposée sur la circulation d'huile, pour arrêter l'arrivée d'huile dans le volume de la pompe lorsque la pompe s'arrête, caractérisée en ce que la circulation d'huile présente un étage de pression (15) pour réduire la surpression produite par la pompe à huile (12) en l'amenant à la pression régnante; et en ce que les embranchements (16,17,18) qui conduisent aux paliers- par rapport à la direction de l'écoulement de l'huile - sont disposés avant l'étage de pression et avant la conduite d'embranchement (44) qui conduit au volume de la pompe tandis que la soupape d'arrêt (14, 41 ) est disposée derrière l'étage de pression.
2. Pompe à vide selon la revendication 1, caractérisée en ce que c'est un étranglement ou une buse (15) qui sert d'étage de pression.
3. Pompe à vide selon l'une des revendications 1 ou 2, caractérisée en ce que l'étage de pression se trouve dans une paroi frontale (22) du corps de pompe (57) disposé dans le carter extérieur de la pompe (1).
4. Pompe à vide selon la revendication 3, caractérisée en ce que la face externe de la paroi frontale (42) présente une ouverture de sortie (14) pour l'huile détendue; en ce qu'à côté de cette ouverture de sortie est disposée une ouverture d'entrée pour la conduite (4) qui conduit vers le volume de la pompe; et en ce que la surface de la paroi frontale a une forme telle que dans la conduite (44) ne parvient que l'huile qui sort en excès de l'ouverture de sortie (14).
5. Pompe à vide selon la revendication 4, caractérisée en ce que l'ouverture de sortie (14) est entourée d'une gorge (43) disposée de préférence concentriquement et qui va jusqu'à la conduite (44) qui conduit vers le volume de la pompe; et en ce qu'il est prévu un obturateur à ressort qui recouvre les deux ouvertures (14, 44) et la gorge (43).
6. Pompe à vide selon la revendication 5, caractérisée en ce que l'obturateur à ressort est constitué d'un tronçon de feuillard d'acier élastique.
7. Pompe à vide selon l'une des revendications 4, 5 ou 6, caractérisée en ce que sur la portion, située à l'intérieur de la paroi (42), de la conduite (44) qui conduit vers le volume de la pompe est disposé un autre étranglement ou une autre buse (45).
8. Pompe à vide selon la revendication 7, caractérisée en ce que la buse (44) est fixée à la paroi frontale (42) au moyen d'un filetage (59).
9. Pompe à vide selon l'une des revendications 4 à 8, caractérisée en ce que la paroi frontale (42) est prévue une conduite (17), qui conduit au palier de l'arbre de pompe de cette paroi frontale et qui est formé d'un alésage de telle sorte qu'elle croise, avant l'étage de pression (15), la conduite sous pression (13) constituant la circulation d'huile; et en ce que cet alésage est fermé vers l'extérieur.
EP82109588A 1981-12-17 1982-10-16 Pompe à vide à joint d'huile Expired EP0084084B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3150000 1981-12-17
DE19813150000 DE3150000A1 (de) 1981-12-17 1981-12-17 Oelgedichtete vakuumpumpe

Publications (2)

Publication Number Publication Date
EP0084084A1 EP0084084A1 (fr) 1983-07-27
EP0084084B1 true EP0084084B1 (fr) 1985-02-06

Family

ID=6148983

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82109588A Expired EP0084084B1 (fr) 1981-12-17 1982-10-16 Pompe à vide à joint d'huile

Country Status (3)

Country Link
US (1) US4525129A (fr)
EP (1) EP0084084B1 (fr)
DE (2) DE3150000A1 (fr)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1207829B (it) * 1987-02-04 1989-06-01 Galileo Spa Off Perfezionamento nel circuito di lubrificazione delle pompe rotative per vuoto.
US4903505A (en) * 1989-01-30 1990-02-27 Hoshizaki Electric Co., Ltd. Automatic ice manufacturing apparatus
JPH02275089A (ja) * 1989-04-13 1990-11-09 Kobe Steel Ltd スクリュ式真空ポンプ
KR950007519B1 (ko) * 1992-09-09 1995-07-11 김영수 로터리 형식의 진공펌프장치
US6190149B1 (en) 1999-04-19 2001-02-20 Stokes Vacuum Inc. Vacuum pump oil distribution system with integral oil pump
US20020170979A1 (en) * 2001-05-21 2002-11-21 Victor Martinez Drainage system
KR100408153B1 (ko) 2001-08-14 2003-12-01 주식회사 우성진공 드라이 진공펌프
US8096781B2 (en) * 2008-09-24 2012-01-17 Caterpillar Inc. Hydraulic pump system with reduced cold start parasitic loss
US9080569B2 (en) * 2009-01-22 2015-07-14 Gregory S. Sundheim Portable, rotary vane vacuum pump with automatic vacuum breaking arrangement
JP5608685B2 (ja) * 2010-01-29 2014-10-15 アルバック機工株式会社 ポンプ
DE102018109866A1 (de) * 2018-04-24 2019-10-24 Nidec Gpm Gmbh Regelbares Schmierölfördersystem für Verbrennungsmaschinen

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB783770A (en) * 1955-09-19 1957-09-25 Gen Motors Corp Improved rotary constant displacement pump
DE1011115B (de) * 1956-05-26 1957-06-27 Leybolds Nachfolger E Rotierende OElluftpumpe nach dem Gasballastprinzip
DE1190134B (de) * 1957-02-07 1965-04-01 Edwards High Vacuum Ltd Drehkolben-Vakuumpumpe mit oelueberlagertem Auspuffventil
GB875444A (en) * 1957-02-07 1961-08-23 Edwards High Vacuum Ltd Improvements in or relating to rotary vacuum pumps
GB899202A (en) * 1959-02-05 1962-06-20 Gunnar Axel Wahlmark Improvements in or relating to fluid delivery systems which deliver at a substantially constant pressure
US3406897A (en) * 1966-07-18 1968-10-22 Leybold Holding Ag Mechanical vacuum pump
GB1126886A (en) * 1966-10-18 1968-09-11 Genevac Ltd Improvements in or relating to rotary vacuum pumps
DE1628285A1 (de) * 1966-10-29 1970-03-19 Leybold Heraeus Gmbh & Co Kg Rotationskolbenvakuumpumpe
GB1303430A (fr) * 1969-06-12 1973-01-17
GB1334225A (en) * 1969-12-16 1973-10-17 Edwards High Vacuum Int Ltd Vacuum pumps
US3838950A (en) * 1970-06-18 1974-10-01 Cenco Inc Vacuum pump with lubricant metering groove
DE2035938C3 (de) * 1970-07-20 1975-10-16 Danfoss A/S, Nordborg (Daenemark) Ölpumpe für Feuerungsanlagen
US3811468A (en) * 1972-03-10 1974-05-21 Fedders Corp Compressor valve assembly
FI761780A (fr) * 1976-06-18 1977-12-19 Rauma Repola Oy
US4120621A (en) * 1976-07-19 1978-10-17 Puritan Bennett Corporation Oil sealed single stage vacuum pump
CA1162171A (fr) * 1979-04-04 1984-02-14 Kaichi Yamada Compresseur rotatif a aubages
DE2948992A1 (de) * 1979-12-05 1981-06-11 Karl Prof.Dr.-Ing. 3000 Hannover Bammert Rotorverdichter, insbesondere schraubenrotorverdichter, mit schmiermittelzufuhr zu und schmiermitteldrainage von den lagern
US4366834A (en) * 1980-10-10 1983-01-04 Sargent-Welch Scientific Company Back-flow prevention valve

Also Published As

Publication number Publication date
DE3150000A1 (de) 1983-07-14
DE3262232D1 (en) 1985-03-21
EP0084084A1 (fr) 1983-07-27
US4525129A (en) 1985-06-25

Similar Documents

Publication Publication Date Title
DE1628144C3 (de) Saugdrosselsteuereinrichtung
DE2708900A1 (de) Regelsystem fuer schraubenverdichter
DE102010044898A1 (de) Vakuumpumpe mit Lüftungseinrichtung
EP0084084B1 (fr) Pompe à vide à joint d'huile
DE10259808B4 (de) Strahlpumpe
AT402542B (de) Ansaugregelventil
DE102005031718A1 (de) Vakuum-Drehschieberpumpe
EP0084085B1 (fr) Pompe à vide avec une soupape dans la tubulure d'aspiration et son procédé de mise en activité
DE2308265A1 (de) Rotations- bzw. drehkolbenverdichter anlage mit oelkreislauf und ventilanordnungen
DE60307662T2 (de) Kompressor mit leistungsregelung
EP0839283B1 (fr) Pompe a vide a palettes rendue etanche a l'huile, avec alimentation en huile
EP0684385A1 (fr) Dispositif de réduction de pression d'un compresseur
DE4301907A1 (de) Flüssigkeitsringmaschine
DE2944053A1 (de) Ansaugsteuervorrichtung fuer einen verdichter
DE8136790U1 (de) Ölgedichtete Vakuumpumpe
EP0528254B1 (fr) Dispositif de régulation pour pompes à déplacement positif
DE3922417C2 (fr)
DE2255986C3 (de) Pumpeinrichtung für eine Hydraulikanlage in einem Kraftfahrzeug
EP0839282B1 (fr) Pompe a vide a palettes rendue etanche a l'huile, avec pompe a huile
DE4135221C2 (de) Flügelzellenpumpe
DE1551651A1 (de) OElfoerderanlage fuer wahlweisen Ein-Strang- oder Zwei-Strang-Betrieb
DE2542118A1 (de) Fluessigkeitsstrahler mit verdraengerpumpe, zweistufenventil und absperrbarer spruehlanze
DE2846005A1 (de) Rotations- bzw. drehkolbenverdichteranlage mit oelkreislauf und absperrorganen
DD207560A5 (de) Steuerungsvorrichtung fuer einen verdichter
DE1428236C (de) Rotierende mechanische Vakuum

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: 19821016

AK Designated contracting states

Designated state(s): CH DE FR GB IT LI

ITF It: translation for a ep patent filed
GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): CH DE FR GB IT LI

REF Corresponds to:

Ref document number: 3262232

Country of ref document: DE

Date of ref document: 19850321

ET Fr: translation filed
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: CH

Ref legal event code: PFA

Free format text: LEYBOLD AKTIENGESELLSCHAFT

REG Reference to a national code

Ref country code: FR

Ref legal event code: CD

Ref country code: FR

Ref legal event code: CA

ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19960911

Year of fee payment: 15

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

Ref country code: CH

Payment date: 19960919

Year of fee payment: 15

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

Ref country code: GB

Payment date: 19960920

Year of fee payment: 15

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

Ref country code: DE

Payment date: 19960923

Year of fee payment: 15

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

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19971016

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

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19971031

Ref country code: FR

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19971031

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19971031

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

Effective date: 19971016

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

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

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19980701

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST