EP0046977A2 - Dispositif pour tendre des lames de scie d'une scie alternative munie d'un dispositif de tension hydraulique - Google Patents

Dispositif pour tendre des lames de scie d'une scie alternative munie d'un dispositif de tension hydraulique Download PDF

Info

Publication number
EP0046977A2
EP0046977A2 EP81106603A EP81106603A EP0046977A2 EP 0046977 A2 EP0046977 A2 EP 0046977A2 EP 81106603 A EP81106603 A EP 81106603A EP 81106603 A EP81106603 A EP 81106603A EP 0046977 A2 EP0046977 A2 EP 0046977A2
Authority
EP
European Patent Office
Prior art keywords
pressure
clamping device
clamping
hydraulic
piston
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.)
Granted
Application number
EP81106603A
Other languages
German (de)
English (en)
Other versions
EP0046977B1 (fr
EP0046977A3 (en
Inventor
Ulrich Bühler
Rudolf Ineichen
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.)
Ulrich Buehler AG Sagen- und Maschinenmesserfabrik
Original Assignee
Ulrich Buehler AG Sagen- und Maschinenmesserfabrik
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 Ulrich Buehler AG Sagen- und Maschinenmesserfabrik filed Critical Ulrich Buehler AG Sagen- und Maschinenmesserfabrik
Priority to AT81106603T priority Critical patent/ATE11020T1/de
Publication of EP0046977A2 publication Critical patent/EP0046977A2/fr
Publication of EP0046977A3 publication Critical patent/EP0046977A3/de
Application granted granted Critical
Publication of EP0046977B1 publication Critical patent/EP0046977B1/fr
Expired legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27B—SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR
    • B27B3/00—Gang saw mills; Other sawing machines with reciprocating saw blades, specially designed for length sawing of trunks
    • B27B3/28—Components
    • B27B3/30—Blade attachments, e.g. saw buckles; Stretching devices
    • B27B3/34—Blade attachments, e.g. saw buckles; Stretching devices the stretching devices being actuated by fluid pressure

Definitions

  • the invention relates to a method for tensioning saw blades of a frame with a hydraulic tensioning device which has at least one piston which can be actuated by a hydraulic fluid.
  • a hydraulic saw clamp is already known, with which all saw blades can be clamped hydraulically at the same time.
  • This saw clamp consists essentially of a unit fastened to the upper latch of the frame, which contains a plurality of hydraulic cylinders arranged next to one another with corresponding pistons. Hydraulic fluid can be applied to these pistons via an oil pump in order to simultaneously clamp all the saw blades attached to the frame.
  • the disadvantage here is that the pistons have only a small stroke , so that additional mechanical clamping means are required to mechanically pretension the saw blades before hydraulic clamping.
  • Another disadvantage is that the center distance between the pistons is fixed, so that the distance between two saw blades is also practically fixed. It is possible that the hinges are not placed exactly in the middle of the piston, but then there is a risk that the piston lying next to it will also attack the rod and double force will be applied, which can cause the rod to tear .
  • certain pistons of the unit are also used more often than others, so that the former and the associated cylinders show signs of wear earlier. However, if even one of the cylinders in the unit is damaged, the entire unit with the many cylinders becomes unusable and must be replaced.
  • the object of the present invention is to avoid these disadvantages.
  • each saw blade is clamped with a separate hydraulic clamping device, and that a clamping tool is attached to the clamping device, and that locking means of the clamping device are actuated to to maintain this pressure in the hydraulic fluid even after the clamping tool has been removed.
  • the pressure in the hydraulic fluid of the tensioning device is advantageously generated in that the tensioning tool effects the connection of the tensioning device to a hydraulic pressure source.
  • the pressure in the hydraulic fluid of the tensioning device is generated in that the tensioning tool is designed as a force transmitter which acts on a pressure piston of the tensioning device.
  • the force transmitter can be operated mechanically, electromechanically, pneumatically or hydraulically.
  • the design of the tensioning tool as a force transmitter has the advantage that a coupling for hydraulic fluid that is relatively time-prone to operate and is relatively susceptible to malfunction is not required. There is then no risk of dirt getting into the hydraulic fluid.
  • the pressure can be generated by a hydraulic piston of the clamping tool.
  • the pressure in the tensioning device is advantageously maintained by closing a valve.
  • the invention also relates to a hydraulic tensioning device with at least one hydraulic piston for tensioning saw blades in a frame.
  • this clamping device is characterized in that it has a body, the width of which is not greater than the smallest usual center distance between two saw blades, that the Body has means for attaching a saw blade or a saw blade tang and that in the body at least on one side of said means there is at least one cylinder bore which serves to receive the hydraulic piston and which is connected to a pressure generator arranged in the body.
  • This clamping device is very simple in construction and inexpensive to manufacture. Only as many clamping devices have to be attached to the frame as saw blades have to be clamped.
  • the other clamping devices which would be necessary to fully equip the frame with saw blades, do not have to be permanently attached to the frame. This reduces the weight and the tensioning devices that are not required also run no risk of damage.
  • Another important advantage is that the so-called center hook in gates with width adjustment can be carried out with hydraulic clamping elements.
  • two pairs of slides are provided with two groups of saw blades, which process the outer parts of the trunk into boards.
  • the pairs of slides with the two groups of saw blades can be adjusted relative to one another depending on the desired width of the beam to be produced.
  • the hydraulic clamping elements can now not only be used for clamping the saw blades arranged between a pair of slides, but also for clamping saw blades that may still be arranged directly on the frame, which is the case, for example, when a thick trunk is divided into several beams should. With the previous hydraulic tensioning devices, the so-called center hook was not possible, which was a serious disadvantage.
  • At least one cylinder bore containing a hydraulic piston is provided on each side of the means for fastening a saw blade.
  • the cylinder bores are expediently connected to one another. This ensures that the same pressure prevails in both holes and therefore on both sides the means for fastening the same forces occur.
  • two cylinder bores, each containing a hydraulic piston are provided on both sides of the means for fastening a saw blade.
  • each hydraulic piston has an extension of small diameter that extends to the bottom of the cylinder bore when the tensioning device is not actuated. This extension serves as a stop with which it is avoided that the piston penetrates deeper than necessary into the cylinder bore. Since the cylinder bore is relatively long, it can absorb a relatively large amount of hydraulic fluid and thereby also serve as a pressure accumulator. In addition, at least one separate pressure accumulator can be provided, which is connected to the cylinder bores. These pressure accumulators advantageously have the shape of cylindrical bores and are expediently arranged in the middle of the tensioning device for receiving additional hydraulic fluid. These accumulators allow a relatively g horses movement of the hydraulic piston, without there will be a greater pressure drop. The arrangement of the pressure accumulators in the form of a bore parallel to the cylinder bores has proven to be particularly expedient.
  • the pressure generator is expediently formed by a piston which is accommodated in a further cylinder bore in the body and which can be actuated from the outside.
  • This configuration allows a very compact structure of the tensioning device and avoids hydraulic lines with all their disadvantages.
  • the piston of the pressure generator can be actuated by mechanical means. These mechanical means can be formed, for example, by a screw that can be rotated in a thread of the body. In this way, pressure generation is possible with very simple means.
  • the invention also encompasses a clamping tool used to carry out the method, which is characterized in that it has a pressure pin for actuating the clamping device, and that a contact surface is formed opposite the pressure pin, which can be brought into contact with a corresponding contact surface of the clamping device.
  • a clamping tool used to carry out the method, which is characterized in that it has a pressure pin for actuating the clamping device, and that a contact surface is formed opposite the pressure pin, which can be brought into contact with a corresponding contact surface of the clamping device.
  • the clamping tool can have a hydraulic cylinder which can be actuated by a pneumatic cylinder and on the piston of which the pressure pin is arranged.
  • Pneumatic actuation is advantageous because a sawmill usually also has a compressed air connection.
  • a hydraulic cylinder which can be actuated by a pneumatic cylinder is provided, it is advantageous if the piston of the hydraulic cylinder has a recess whose diameter is larger than a pin projecting into the recess from the pneumatic cylinder. In this way, a strengthening is achieved.
  • a gate frame 10 which consists of two columns 11 and the upper and lower bars 13, 15.
  • two groups of saw blades 19 are provided on two pairs of carriages 12 for sawing the trunk 16. These slides 12 can be moved relative to one another on the associated latches 13, 15. For each saw blade 19, irrespective of whether it is arranged between a pair of slides or directly between the bars 13, 15, as shown in the middle in FIG. 1, a separate clamping device 21 is provided for clamping.
  • Fig. 2 the upper bar 13 of the gate frame 10 is again visible, but from the side and in section. Is shown Further, in Fig. 1 in the middle of the gate frame 10 n ete clamping device 21 angeord with the vertical extension 23 which is a spigot 25 for receiving a hook 27 auf utilizat.In for the saw blade 19 Fig. 2 also an embodiment of a clamping tool 29 can be seen which will be described later with reference to FIG. 5.
  • the structure of the hydraulic tensioning device 21 can be seen from FIG., which represents a partial section.
  • the clamping device 21 consists essentially of an approximately prismatic body 31 which has an extension 23 approximately in the middle with means, e.g. has a pin 25 for fastening a saw blade or a saw blade tang.
  • the width of the body 31 is not greater than the smallest common center distance between two saw blades 19.
  • two cylinder bores 37 are arranged on both sides of the extension 23, in which hydraulic pistons 39 are arranged. It would also be possible to provide only one cylinder bore 37 with a piston 39 on both sides. When using a plurality of cylinder bores 37, however, the available space is better utilized and lower hydraulic pressures can be used.
  • the arrangement of the cylinder bores 37 advantageously takes place symmetrically to the central axis 38. In this way, forces acting laterally on the cylinder walls can be practically avoided.
  • the pistons 39 are biased by springs 41 in the direction of the cylinder bore 37.
  • the springs 41 rest against the end plate 43, which is fastened to the body 31 with screws (not shown).
  • the pistons 39 have an extension 35 of small diameter extending to the bottom of the cylinder bore 37. This extension 35 serves as a stop and prevents the piston from entering the cylinder bore 37 further than necessary. Since the extension 35 has a small diameter, a relatively large amount of hydraulic fluid has space in the respective cylinder bore 37.
  • the cylinder bores 37 therefore also serve as hydraulic pressure accumulators.
  • the pistons 39 have a sealing ring 47 in the usual way. An additional guide surface 49 is provided for better guidance of the piston 39.
  • the cylinders 37 are connected to one another and to two pressure accumulators 55 via bores 52, 53, 54, 56, 58. These pressure accumulators 55 are formed by two bores parallel to the cylinder bores 37, which bores were subsequently closed by welding in covers 37 '. Thanks to the relatively large volume of the hydraulic fluid in the cylinder bores 37 and the additional bores 55, there is a favorable displacement / force characteristic for the pistons 39. In other words, this means that after the saw blades have been tensioned, the pistons 39 travel a relatively large distance can without the clamping force acting on the saw blades dropping sharply.
  • a pressure generator 57 is also provided in the tensioning device 21, which essentially consists of a further cylinder bore 58 ', a piston 59 and a return spring 63.
  • This piston 59 has a sealing ring 61 in the usual way.
  • An end plate 70 which is fastened to the body 31 with screws (not shown), has an opening 72 with a smaller diameter than the cylinder bore 58 'and thus prevents the piston 59 from falling out.
  • the cylinder bore 58 'of the pressure generator can correspond to the generation of a pressure in the cylinder bores 37 with these via the bores 65, 66, 66', 66 ".
  • the ball valve is closed by tightening the screw 67.
  • the ball valve consists of the ball 68 and the piston 68 ', it is also conceivable to use a different valve, for example a check valve, in which case the need to tighten the screw 67 could be eliminated, but means would then have to be provided to loosen it the clamping device to lower the pressure in the clamping device.
  • the end plates 43 and 70 are advantageously provided with centering means 44, e.g. Provide projections which fit into recesses 93 of the clamping tool 29 shown in FIG. 5 in order to center it.
  • centering means 44 e.g. Provide projections which fit into recesses 93 of the clamping tool 29 shown in FIG. 5 in order to center it.
  • a threaded vent hole 75 is used to vent the tensioning device 21 when filling the hydraulic fluid.
  • the filling can take place, for example, through the bore 66 before the valve parts 68, 68 'and 67 are inserted, the tensioning device being arranged in such a way that the vent hole 75 is directed upward.
  • the pressure generator 57 is designed in such a way that it can be actuated by a clamping tool shown in FIGS. 2, 5 and 6, which generates a pressure in the direction of the arrow 69.
  • a clamping tool shown in FIGS. 2, 5 and 6, which generates a pressure in the direction of the arrow 69.
  • the use of a pressure generator 57 is more advantageous because when using a hydraulic tensioning device 21 with pressure generator 57, tensioning can be accomplished in a very simple and very rapid manner.
  • the hydraulically actuated clamping tool 29 shown in FIG. 5 has a hydraulic cylinder 86 with a pressure pin 89 '. Opposite this pressure pin 89 ', the clamping tool has a contact surface 91 at a distance which is slightly greater than the height of the clamping device, which can be brought into contact with a corresponding contact surface 93 (FIG. 3) of the clamping device.
  • the tool 29 has a rotatably mounted key 94 for opening and closing the Valve screw 67 of the tensioning device 21.
  • the key 9 consists of the rotatable shaft 95, on which a lever 96 is attached.
  • the clamping tool has a handle 97 which is formed by an opening 92.
  • the individual clamping devices 21 can be easily actuated by attaching the clamping tool 29 to the clamping device 21, recesses 93 or the like adapted to the centering means 44 ensuring centering. Then hydraulic pressure; e.g. generated by a hydraulic pump so that the pressure pin 89 'acts on the piston 59 of the pressure generator 57. By actuating the handle 96, the valve 68, 68 'is then closed, so that the hydraulic pressure is still maintained in the clamping device 21 even when the clamping tool 29 is removed. Since the latches 13, 15 of the frame 10 can spring somewhat, it may be necessary to repeat the tensioning operation again after the first tensioning. However, it would also be possible to pre-tension the hinges mechanically in a known manner before hydraulic tensioning. In most cases, however, it proves to be expedient to dispense with mechanical pretensioning because this simplifies both the tensioning device and the tensioning operation.
  • Fig. 6 shows another embodiment of a clamping tool 29.
  • a pneumatic cylinder 81 is provided, the piston 83 has a pin 84 projecting through an opening 85 in a hydraulic cylinder 86.
  • the piston 87 has a recess 88, the diameter of which is larger than that of the pin 84. This recess is filled with hydraulic fluid.
  • Return springs 89 and 90 are provided both for the pneumatic piston 83 and for the hydraulic piston 87.
  • a pneumatic-hydraulic booster is created by the two cylinders 81, 86.
  • a pressure pin 89 ' is provided on the piston 87.
  • the clamping tool by a distance which is slightly greater than the height of the S p annein- direction, a support surface 91 on which a entspre Appropriate contact surface 93 'of the clamping device 21 can be brought into contact.
  • the clamping device 21 shown in FIG. 4 has a correspondingly designed pressure generator 57. Otherwise, the tensioning device 21 can be constructed in the same way as shown in FIG. 3.
  • the pressure generator 57 according to FIG. 4 the pressure is generated by a screw 71, which acts on the piston 59.
  • a hexagon wrench (not shown) into the hexagon opening 73 of the screw 71 and to turn it in the thread 74 such that the piston 59 is moved downward.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Wood Science & Technology (AREA)
  • Forests & Forestry (AREA)
  • Sawing (AREA)
  • Treatment Of Fiber Materials (AREA)
  • Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
EP81106603A 1980-09-02 1981-08-26 Dispositif pour tendre des lames de scie d'une scie alternative munie d'un dispositif de tension hydraulique Expired EP0046977B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT81106603T ATE11020T1 (de) 1980-09-02 1981-08-26 Auf einem gatterrahmen anbringbare hydraulische spanneinrichtung zum spannen von saegeblaettern.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH659680 1980-09-02
CH6596/80 1980-09-02

Publications (3)

Publication Number Publication Date
EP0046977A2 true EP0046977A2 (fr) 1982-03-10
EP0046977A3 EP0046977A3 (en) 1983-02-16
EP0046977B1 EP0046977B1 (fr) 1985-01-02

Family

ID=4312078

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81106603A Expired EP0046977B1 (fr) 1980-09-02 1981-08-26 Dispositif pour tendre des lames de scie d'une scie alternative munie d'un dispositif de tension hydraulique

Country Status (3)

Country Link
EP (1) EP0046977B1 (fr)
AT (1) ATE11020T1 (fr)
DE (1) DE3168038D1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3512821C1 (de) * 1985-04-10 1986-10-30 Adolf 8961 Weitnau Gudermann Hydraulische Spannvorrichtung zum Spannen von Sägeblättern in Gatterrahmen
US4682525A (en) * 1985-04-24 1987-07-28 Richard Jansen Gmbh Hydraulic saw frame with external sealing means
CN115104448A (zh) * 2022-06-08 2022-09-27 浙江师范大学 一种链条自动张紧的链锯

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE661577C (de) * 1934-10-21 1938-06-22 Alfons Wasserkampf Vorrichtung zum gemeinsamen Spannen saemtlicher Saegen in Vollgattern
DE1013412B (de) * 1953-09-11 1957-08-08 Jansen Fa R Hydraulische Spannvorrichtung zum gemeinsamen Spannen saemtlicher Saegen in Vollgattern
DE1169641B (de) * 1960-01-26 1964-05-06 Josef Thoeress Hydraulischer Saegenspanner
DE1453158A1 (de) * 1963-08-16 1969-07-17 Karl Rupprecht Hydraulischer Saegenspanner
DE1503928A1 (de) * 1965-05-04 1969-08-07 Andreas Bank Spannvorrichtung fuer das Saegeblatt von Gattersaegen
DE2656961C2 (de) * 1976-12-16 1983-12-29 Fa. Richard Jansen, 5630 Remscheid Vorrichtung zum Spannen von Sägeblättern in Gatterrahmen von Gattersägen

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3512821C1 (de) * 1985-04-10 1986-10-30 Adolf 8961 Weitnau Gudermann Hydraulische Spannvorrichtung zum Spannen von Sägeblättern in Gatterrahmen
US4682525A (en) * 1985-04-24 1987-07-28 Richard Jansen Gmbh Hydraulic saw frame with external sealing means
CN115104448A (zh) * 2022-06-08 2022-09-27 浙江师范大学 一种链条自动张紧的链锯
CN115104448B (zh) * 2022-06-08 2023-04-18 浙江师范大学 一种链条自动张紧的链锯

Also Published As

Publication number Publication date
DE3168038D1 (en) 1985-02-14
ATE11020T1 (de) 1985-01-15
EP0046977B1 (fr) 1985-01-02
EP0046977A3 (en) 1983-02-16

Similar Documents

Publication Publication Date Title
DE3723494C2 (de) Spannvorrichtung
CH647698A5 (de) Spannvorrichtung zur befestigung einer biegeschiene im stoessel einer abkantpresse.
DE2717336A1 (de) Pneumatischer hammerantrieb
DE1966880C3 (de) Abschereinrichtung für eine Quertransportpresse
DE69302524T2 (de) Werkzeughalter für einen hydraulischen Schlaghammer
EP0558931A1 (fr) Buse à fermeture à aiguille avec entraînement à piston
DE69109693T2 (de) Montage-grundkörper für führungsschienen.
DE7928194U1 (de) Hydraulische stossdaempfvorrichtung, insbesondere fuer abscherpressen
EP0143257B1 (fr) Raccordement d'outil d'une presse de découpage, notamment d'une presse de découpage à plateau revolver, pour le changement d'outil
EP0046977B1 (fr) Dispositif pour tendre des lames de scie d'une scie alternative munie d'un dispositif de tension hydraulique
EP0605698B1 (fr) Presse a leviers articules
EP0107642A1 (fr) Soudeuse de treillis à points multiples
DE3025156A1 (de) Presse mit einem stanz- und/oder presswerkzeug
DE2510083C3 (de) Kletterhebevorrichtung
EP0919729A2 (fr) Vérin avec tige de piston guidé sans rotation
EP0331777B1 (fr) Dispositif pour fixer, par tension, un revêtement sur un cylindre d'une machine rotative
DE69708599T2 (de) An einem träger befestigte hydraulische pumpe
EP1468787B1 (fr) Appareil universel de levage et de séparation
DE3119694C2 (de) Steinspaltwerkzeug
DE1575205A1 (de) Schwalbenschwanzartige Verbindung von Maschinenelementen
AT380501B (de) Widerlager fuer einrichtungen zum verschieben schwerer konstruktionsteile wie brueckenteile, tragelemente, traeger u.dgl.
DE69620502T2 (de) Verfahren und Vorrichtung zum Aufbrechen von Türen
DE1552289C (de) Kraftbetatigte Spannvorrichtung , ins besondere Backenfutter
DE1627604A1 (de) Klemmvorrichtung fuer Praegestempel
AT224051B (de) Abnehmbare hydraulische Spannvorrichtung

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

AK Designated contracting states

Designated state(s): AT BE CH DE FR IT SE

17P Request for examination filed

Effective date: 19820526

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Designated state(s): AT BE CH DE FR IT LI SE

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

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): AT BE CH DE FR IT LI SE

REF Corresponds to:

Ref document number: 11020

Country of ref document: AT

Date of ref document: 19850115

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3168038

Country of ref document: DE

Date of ref document: 19850214

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

Ref country code: SE

Effective date: 19860827

BERE Be: lapsed

Owner name: ULRICH BUHLER A.G. SAGEN- UND MASCHINENMESSERFABR

Effective date: 19860831

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

Ref country code: BE

Effective date: 19890831

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

Ref country code: DE

Payment date: 19900806

Year of fee payment: 10

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

Ref country code: AT

Payment date: 19900809

Year of fee payment: 10

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

Ref country code: FR

Payment date: 19900828

Year of fee payment: 10

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

Ref country code: CH

Payment date: 19900831

Year of fee payment: 10

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

Ref country code: AT

Effective date: 19910826

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

Ref country code: LI

Effective date: 19910831

Ref country code: CH

Effective date: 19910831

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

Ref country code: FR

Effective date: 19920430

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

Effective date: 19920501

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

EUG Se: european patent has lapsed

Ref document number: 81106603.4

Effective date: 19870812