EP0366051B1 - Coussin produisant un gel nouveau et procédé pour surfacer et polir des lentilles - Google Patents

Coussin produisant un gel nouveau et procédé pour surfacer et polir des lentilles Download PDF

Info

Publication number
EP0366051B1
EP0366051B1 EP19890119666 EP89119666A EP0366051B1 EP 0366051 B1 EP0366051 B1 EP 0366051B1 EP 19890119666 EP19890119666 EP 19890119666 EP 89119666 A EP89119666 A EP 89119666A EP 0366051 B1 EP0366051 B1 EP 0366051B1
Authority
EP
European Patent Office
Prior art keywords
pad
surfacing
workpiece
abrasive
gel
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 - Lifetime
Application number
EP19890119666
Other languages
German (de)
English (en)
Other versions
EP0366051A1 (fr
Inventor
Mark M. Mayton
Alan J. Lopresti
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.)
Vibrantz Corp
Original Assignee
Ferro Corp
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 Ferro Corp filed Critical Ferro Corp
Publication of EP0366051A1 publication Critical patent/EP0366051A1/fr
Application granted granted Critical
Publication of EP0366051B1 publication Critical patent/EP0366051B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
    • B24D3/001—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as supporting member
    • B24D3/002—Flexible supporting members, e.g. paper, woven, plastic materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B13/00—Machines or devices designed for grinding or polishing optical surfaces on lenses or surfaces of similar shape on other work; Accessories therefor
    • B24B13/01—Specific tools, e.g. bowl-like; Production, dressing or fastening of these tools
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
    • B24D3/02—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent
    • B24D3/20—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially organic

Definitions

  • This invention relates to an improved method and product for surfacing and/or polishing lenses and the like. More particularly, this invention relates to a novel gel producing fining or polishing pad which considerably simplifies the process of fining and/or polishing lenses.
  • the process for producing fine ground or polished surfaces on optical materials is much the same regardless of the type of fining or polishing medium employed, or the type of material being processed.
  • a fining or polishing pad is moved across the surface of the material to be processed, while either a slurry containing abrasive particles, or plain water, is directed in a stream between the pad and the surface to be processed.
  • U.S. patent No. 4,255,164 discloses a glass fining pad or sheet having a water insoluble, microcellular matrix containing abrasive fining particles. When the pad is used with an aqueous flow or stream its matrix breaks down and allegedly releases the fining particles at a controlled rate. While being effective for the grinding or fining stages of surfacing, this type of pad is not effective for polishing, even when using a polishing grade abrasive.
  • U.S. patent No. 4,576,612 discloses a polishing pad having a water soluble matrix containing polishing particles. A stream of water which is directed onto the interface between the pad and the work causes the exposed surface of the matrix slowly to dissolve thus slowly releasing polishing particles.
  • U.S. patent No. 3,042,509 also discloses a wax-like, polyethylene based polishing compound containing polishing particles, and adapted to be rubbed onto the surface of a buffing wheel or lap to provide both lubricating and polishing properties for the wheel or lap surface.
  • the compound is water-soluble so that it can be washed off of the wheel after the buffing operation.
  • One object of this invention is to provide an improved fining or polishing process which eliminates the need for directing a stream of water or liquid slurry onto the work, thereby circumventing many of the problems associated with the previously mentioned processes.
  • Still another object is to provide a novel water absorbent or adsorbent pad which, when wetted, makes all of its abrasive material instantly available for fining or polishing.
  • a further object of this invention is to provide a novel pad of the type described having an abrasive-containing matrix made from a polymer which can absorb and retain large amounts of water to enable formation of a long lasting gel.
  • the hereinafter described pad provides a disposable, self-contained article for fining or polishing the surfaces of various materials (plastics, metals, glass, ceramics, etc.) using only a small amount of a liquid agent to produce between the pad and the work a gel which contains abrasive particles (fining or polishing).
  • the abrasive particles (aluminum oxide, cerium oxide, etc.) are dispersed in a water absorbent or adsorbent, gel-producing carrier or matrix, which is coated uniformly onto a flexible reinforcing substrate, such as for example a fabric of the type used for conventional polishing or finishing pads.
  • An adhesive is applied to the back of the substrate, and the entire structure is cut to form a conventionally shaped, multi-petal pad.
  • the pad is attached to a surfacing lap and its matrix and substrate are wetted with a small amount of liquid. The motion of the lap forms on the pad a gel, which acts like a viscous slurry to surface the associated workpiece
  • the optimum abrasive carrier or matrix provides rapid gelation, uniform dispersion of surfacing agent, lubrication between the lap or other surfacing substrate and the object being fined or polished, and produces a viscous matrix which retains or prevents loss of the abrasive.
  • the preferred, matrix-supporting substrate is a fabric capable of absorbing water to function as a reservoir for the gel produced during use. The replacement of a slurry with a gel producing matrix eliminates the need for preparing, storing, and disposing of liquid slurries. It also reduces machine maintenance and cleanup-time.
  • 10 denotes generally a gel producing surfacing pad having therein the usual radial slots 11, which lend to the pad the conventional appearance of a petal-shaped pad.
  • Pad 10 comprises several parts, each of which is responsible for a distinct function.
  • 12 denotes the attachment layer - which, as noted hereinafter is used to attach the pad 10 to a lap or the like.
  • This layer 12 may be any adhesive well known to the industry, such as for example a PSA adhesive.
  • Numeral 14 denotes the substrate layer.
  • This layer has several functions. It provides an intermediate supporting layer between the attachment layer 12 and the hereinafter described surfacing layer; it provides a pliable surface which keeps the hereinafter described abrasive particles in contact with the surface which is being polished or fined; it retains a small amount of abrasive particles in its structure; and in use it acts a a reservoir for the wetting liquid.
  • Any number of synthetic or natural pliable sheet materials can be used for the substrate layer 14, including but not limited to cotton, felt, paper, and woven or non-woven synthetics. These materials can be a flocked form, or may be altered in other ways (perforated, embossed, etc.) to help them retain abrasive particles and the surfacing layer or particle carrier layer.
  • the surfacing or particle carrier layer is denoted at 15, and comprises, preferably, a water absorbent matrix 16 containing abrasive particles 17.
  • Layer 15 is the key component of the gel producing abrasive pad, and as noted hereinafter usually is coated as a paste onto substrate 14 in the range of approximately 10 milligrams to more than 250 milligrams of paste per square centimeter of the substrate surface. When applied in this manner, part of the matrix 16 and its particles 17 penetrate to a certain extent into the fabric substrate (Fig. 2), particularly in those cases where layer 14 is flocked or felted. Layer 15 has multiple functions which should be balanced to produce a good quality surface in the shortest amount of time.
  • the abrasive particles 17 preferably have a Knoop hardness of greater than 1000, and are of a particle size distribution which allows for rapid stock removal with the least amount of scratches left on the surface.
  • the particles 17 preferably should have an average particle size of 0.1 to 10.0 micrometers or microns, and for fining pads a range of from 10.0 to 50.0 micrometers is recommended.
  • Abrasives that can be used include, but are not limited to, cerium oxide, aluminum oxide, silica, etc.
  • the gelling agent or matrix 16 which forms a gel on contact with a liquid, provides a medium which holds the abrasive particles 17 in the presence of a liquid between the substrate 14 and the material being surfaced (not illustrated).
  • the matrix 16 is capable of holding relatively large amounts of liquid, which takes on swarf from the abraded surface, provides lubrication between the pad and the object being surfaced, and can provide cooling to materials which are heat sensitive.
  • Materials suitable for creating matrix 16 include cellulose based materials, clays, alumina-silicates, polymer silicas, and similar materials.
  • Other additives can be used in conjunction with the gelling agent or matrix 16, such as chemical polishing accelerators, coolants, oxidation inhibitors, etc.
  • Part B was then mixed into Part A until the mixture was a smooth paste.
  • Ratio of abrasive (150 gr.) to dry carrier (10 gr.) was 15:1.
  • the mixture of parts A and B was then coated as a layer 15 onto a pad substrate 14 which comprised of a commercially availlable flocked polyester fabric such as 0.5 mm (0.020 inch) rayon flock sold by Tempo/Shane of Peabody Mass.
  • a pad substrate 14 which comprised of a commercially availlable flocked polyester fabric such as 0.5 mm (0.020 inch) rayon flock sold by Tempo/Shane of Peabody Mass.
  • the layer 15 of paste was coated on substrate 14 to a thickness of approximately 0.13-0.2 mm (0.005 - 0.008 inches).
  • the fabric substrate 14 was then placed in an oven at 184°C (300° F). for five minutes. After cooling the fabric, a pressure sensitive adhesive layer 12 was attached to the back of layer 14, and pad 10 was cut to its desired shape using a steel rule die.
  • Each of a first set of polishing pads made according to Example No. 1 was mounted on a lap 20 and saturated with about 20 ml. of water, enough to wet the matrix 16 and to saturate the reservoir layer or substrate 14.
  • the lap was put on a Coburn 505 polishing machine set on low speed and at a pressure of at 1.4 kg/cm2 (20 psi).
  • a fined plastic lens (Supremacy 65 from Coburn Optical Industries, Muskogee, OK.) was mounted and (polished) run for three minutes for each pad.
  • a second set of pads was prepared and run using the same procedure, except that in preparing part A of Example No. 1, the amount of propylene glycol was increased to 40 grams, and each pad was not saturated with water.
  • a third set of pads was prepared and run using the same gel/abrasive matrix and polyester fabric as in the first set, but the uncoated pad fabric was first attached to the lap, after which 4 grams of paste was smeared onto each pad.
  • This mixture was coated as a layer 15 onto a 0.13 mm (0.005 inch) glass- polishing fabric substrate, which was the type sold by Pellon of Chelmsford, Ma., at a thickness of 0.13 mm (.005 inches), and placed in a 184°C (300° F). oven until dry.
  • the cooled material was laminated to a pressure sensitive adhesive layer 17 and a multi-petal pad was die-cut from this material.
  • the fining pad of Example No. 2 was mounted on a lap 20 and saturated with about 20 milliliters of water.
  • the lap was put on a Coburn 505 polishing machine set on low speed at a pressure of 1.4 kg/cm2 (20 psi).
  • a plastic lens was mounted and run (fined) for two minutes by the pad of Example No. 2.
  • the paste was coated on a flocked polyester pad or substrate 14, which was then attached to a polishing lap.
  • the lap was attached to a Coburn 505 polishing machine and run for three minutes on low speed at a pressure of 1.4 kg/cm2 (20 psi).
  • a plastic lens was used.
  • gel is intended to have its common meaning such as for example of substance which is a colloid in which the disbursed phase has combined with the continuous phase to produce a semisolid material, such as a jelly.
  • the present invention considerably simplifies the process and apparatus heretofore required to fine grind and/or to polish rigid surfaces, such as for example the surfaces of optical lenses.
  • a special gel-producing pad it is possible to eliminate the need for directing a stream of liquid slurry or water onto the interface between a pad and lens, for example, thus eliminating also the need for using recirculating pumps and/or filters for directing a slurry continuously onto the work during a surfacing operation.
  • the novel pad disclosed herein it is necessary only to wet the surface of the pad at the commencement of a surfacing operation, and possibly to squirt a supplemental amount of liquid onto the pad during prolonged surfacing operations.
  • the ratio of abrasive to dry carrier be kept as high as possible.
  • pads of the type disclosed herein can be utilized to surface rigid products or work pieces other than optical lenses, for example in the lapidary and gem making art.
  • other organic compounds could be used as gel producing matrices, such as for example polyvinyl alcohol, polyethelene glycol, alginates, gums, and combinations thereof, they are not quite as effective as the above-noted water absorbing or retaining materials such as cellulose based materials and the like.
  • fabric substrates such as denoted at 14, other flexible, water absorbing and retaining substrates could be employed without departing from the invention.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Polishing Bodies And Polishing Tools (AREA)
  • Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
  • Grinding And Polishing Of Tertiary Curved Surfaces And Surfaces With Complex Shapes (AREA)
  • Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

Claims (8)

  1. Article abrasif de surfaçage, comprenant un substrat flexible, une couche flexible à matrice sur la surface de ce substrat, et un certain nombre de particules abrasives dispersées à travers cette couche à matrice, et caractérisée par le fait que cette couche à matrice contient un matériau sélectionné parmi le groupe de matériaux comprenant les matériaux à base de cellulose, l'argile et les dioxydes de silicium, les gommes, l'alcool polyvinylique, le polyéthylène-glycol, les alginates, et les combinaisons de ces matériaux, et qui devient opératif en étant humidifié avec un liquide pour former un gel qui retient les particules abrasives en présence de ce liquide, et que le substrat contient un matériau absorbant l'eau faisant fonction de réservoir pour le liquide utilisé pour humidifier la couche en matrice.
  2. Article abrasif de surfaçage selon la revendication 1, dans lequel les particules abrasives présentent une dureté Knoop d'au moins 1000, et une taille moyenne de l'ordre de 0,1 à 50,0 micromètres.
  3. Article abrasif de surfaçage selon la revendication 1 ou 2, dans lequel le substrat est fait d'une étoffe absorbante.
  4. Article abrasif de surfaçage selon l'une des revendications précédentes, dans lequel le rapport du poids des particules abrasives au poids du matériau contenant la couche en matrice est compris entre les rapports approximatifs de 2,5:1 et 15:1.
  5. Procédé de préparation d'une surface de qualité optique sur une pièce à usiner, comprenant la fourniture d'un coussin de surfaçage doté d'un substrat flexible absorbant le liquide et enduit d'une matrice flexible dotée d'un certain nombre de particules abrasives y dispersées, l'application d'un liquide à cette matrice et à ce substrat, et le frottage des surfaces de la pièce à usiner et de la matrice l'une par rapport à l'autre, et caractérisé par le fait que la matrice contient un matériau sélectionné parmi le groupe de matériaux comprenant les matériaux à base de cellulose, l'argile et les dioxydes de silicium, les gommes, l'alcool polyvinylique, le polyéthylène-glycol, les alginates, et les combinaisons de ces matériaux, capable de produire un gel lorsqu'il est humidifié, et que ce liquide est appliqué sur le coussin dans un quantité juste suffisante pour saturer le substrat et pour créer un gel de surfaçage abrasif et visqueux entre la pièce à usiner et le coussin de substrat.
  6. Procédé selon la revendication 5, incluant l'application du liquide sur le coussin avant de commencer à frotter une surface par rapport à l'autre, et terminant le surfaçage de la pièce à usiner sans appliquer aucun liquide supplémentaire au coussin.
  7. Procédé de préparation d'une surface de qualité optique sur une pièce à usiner, comprenant la fourniture d'une pièce à usiner et d'un coussin de surfaçage, la préparation d'un gel visqueux d'une consistance pâteuse et abrasif en mélangeant de l'eau, des particules abrasives, et un matériau sélectionné parmi le groupe de matériaux comprenant les matériaux à base de cellulose, les argiles, les dioxydes de silicium, les gommes, l'alcool polyvinylique, le polyéthylène-glycol, les alginates et les combinaisons de ces matériaux, l'interposition d'une couche de ce gel d'une consistance pâteuse entre le coussin et la surface à travailler de la pièce à usiner, et le frottement du coussin de surfaçage contre la surface de la pièce à usiner alors que le gel est interposé entre les deux, en retirant le matériau de la surface de la pièce à usiner sans appliquer aucun liquide supplémentaire à l'interface entre le coussin et la pièce à usiner.
  8. Procédé selon la revendication 7, incluant l'application d'une couche de gel de consistance pâteuse au coussin à surfacer avant de commencer à frotter le coussin contre la surface de la pièce à usiner.
EP19890119666 1988-10-26 1989-10-24 Coussin produisant un gel nouveau et procédé pour surfacer et polir des lentilles Expired - Lifetime EP0366051B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US26283888A 1988-10-26 1988-10-26
US262838 1988-10-26

Publications (2)

Publication Number Publication Date
EP0366051A1 EP0366051A1 (fr) 1990-05-02
EP0366051B1 true EP0366051B1 (fr) 1993-03-10

Family

ID=22999282

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19890119666 Expired - Lifetime EP0366051B1 (fr) 1988-10-26 1989-10-24 Coussin produisant un gel nouveau et procédé pour surfacer et polir des lentilles

Country Status (5)

Country Link
EP (1) EP0366051B1 (fr)
JP (1) JP2796678B2 (fr)
CA (1) CA2001487C (fr)
DE (1) DE68905297T2 (fr)
MX (1) MX171378B (fr)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0641110B2 (ja) * 1990-01-22 1994-06-01 ソマール株式会社 研磨フィルムの製造方法
JPH069869U (ja) * 1992-05-19 1994-02-08 裕一 市口 研磨具
JP2595909Y2 (ja) * 1992-08-24 1999-06-02 ホーヤ株式会社 レンズ研磨用パッド
BR9307667A (pt) * 1992-12-17 1999-08-31 Minnesota Mining & Mfg Suspensão apropriada para uso na produção de artigos abrasivos, abrasivo revestido, e, processo para fabricar um abrasivo revestido
US6638144B2 (en) 2000-04-28 2003-10-28 3M Innovative Properties Company Method of cleaning glass
JP2003531737A (ja) * 2000-04-28 2003-10-28 スリーエム イノベイティブ プロパティズ カンパニー ガラスを清浄にする方法
DE102004003131A1 (de) † 2004-01-15 2005-08-11 Carl Zeiss Vorrichtung und Verfahren zum Polieren einer optischen Fläche, optisches Bauelement, sowie Verfahren zum Herstellen eines Polierwerkzeugs
CN115339121B (zh) * 2021-05-12 2024-06-07 华侨大学 一种柔性溶胶凝胶抛光块体的制备方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4255164A (en) * 1979-04-30 1981-03-10 Minnesota Mining And Manufacturing Company Fining sheet and method of making and using the same
US4576612A (en) * 1984-06-01 1986-03-18 Ferro Corporation Fixed ophthalmic lens polishing pad
JPS61195183A (ja) * 1985-02-22 1986-08-29 インタ−ナショナル　ビジネス　マシ−ンズ　コ−ポレ−ション 研磨粉固定型ポリウレタン研磨材料
US4652275A (en) * 1985-08-07 1987-03-24 Minnesota Mining And Manufacturing Company Erodable agglomerates and abrasive products containing the same

Also Published As

Publication number Publication date
DE68905297T2 (de) 1993-06-17
DE68905297D1 (de) 1993-04-15
EP0366051A1 (fr) 1990-05-02
JP2796678B2 (ja) 1998-09-10
CA2001487C (fr) 1994-03-22
JPH02167662A (ja) 1990-06-28
MX171378B (es) 1993-10-21
CA2001487A1 (fr) 1990-04-26

Similar Documents

Publication Publication Date Title
US5000761A (en) Gel producing pad and improved method for surfacing and polishing lenses
US4255164A (en) Fining sheet and method of making and using the same
US4576612A (en) Fixed ophthalmic lens polishing pad
US4138228A (en) Abrasive of a microporous polymer matrix with inorganic particles thereon
EP0320146B1 (fr) Article à polir le verre
AU724347B2 (en) Structured abrasives with adhered functional powders
US5863306A (en) Production of patterned abrasive surfaces
US6080215A (en) Abrasive article and method of making such article
US6277160B1 (en) Abrasive article and method of making such article
US5104421A (en) Polishing method of goods and abrasive pad therefor
US4338748A (en) Grinding tool metal machining
KR20070008717A (ko) 미세마무리를 위한 지지 슈 및 방법
JPH09511454A (ja) 研磨用品、研磨用品の作製方法、および研磨用品の使用方法
JPH07186030A (ja) 光学レンズの研磨仕上げ方法
EP0366051B1 (fr) Coussin produisant un gel nouveau et procédé pour surfacer et polir des lentilles
US5586926A (en) Method for texturing a metallic thin film
US6638144B2 (en) Method of cleaning glass
CA1122017A (fr) Feuille de polissage de feuilles de verre, et methode fabrication et mode d'emploi de ladite feuille
EP1276592B1 (fr) Procede de nettoyage de verre
KR820001476B1 (ko) 연 마 판
JPH0761609B2 (ja) 研磨方法及びこれに用いる研磨パッド
GB1575867A (en) Article for preparation of critical surfaces
CS267059B1 (en) Method of used articles treatment
CS198759B1 (cs) Způsob výroby brusných a leštících nástrojů
MXPA99006382A (en) Rotogravure process for production of patterned abrasive surfaces

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

Kind code of ref document: A1

Designated state(s): BE DE FR GB IT NL

17P Request for examination filed

Effective date: 19900908

17Q First examination report despatched

Effective date: 19920330

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE DE FR GB IT NL

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

Ref country code: BE

Effective date: 19930310

Ref country code: NL

Effective date: 19930310

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRE;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.SCRIBED TIME-LIMIT

Effective date: 19930310

REF Corresponds to:

Ref document number: 68905297

Country of ref document: DE

Date of ref document: 19930415

ET Fr: translation filed
NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
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
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20001003

Year of fee payment: 12

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

Ref country code: GB

Payment date: 20001004

Year of fee payment: 12

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

Ref country code: FR

Payment date: 20010115

Year of fee payment: 13

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: 20011024

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

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

Effective date: 20011024

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

Ref country code: FR

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

Effective date: 20020628

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: 20020702

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST