GB1562922A - Laser welding - Google Patents

Laser welding Download PDF

Info

Publication number
GB1562922A
GB1562922A GB43872/76A GB4387276A GB1562922A GB 1562922 A GB1562922 A GB 1562922A GB 43872/76 A GB43872/76 A GB 43872/76A GB 4387276 A GB4387276 A GB 4387276A GB 1562922 A GB1562922 A GB 1562922A
Authority
GB
United Kingdom
Prior art keywords
strips
point
laser beam
converging
inch
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
GB43872/76A
Other languages
English (en)
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.)
Union Carbide Corp
Original Assignee
Union Carbide 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 Union Carbide Corp filed Critical Union Carbide Corp
Publication of GB1562922A publication Critical patent/GB1562922A/en
Expired legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/08—Devices involving relative movement between laser beam and workpiece
    • B23K26/083—Devices involving movement of the workpiece in at least one axial direction
    • B23K26/0838—Devices involving movement of the workpiece in at least one axial direction by using an endless conveyor belt
    • B23K26/0846—Devices involving movement of the workpiece in at least one axial direction by using an endless conveyor belt for moving elongated workpieces longitudinally, e.g. wire or strip material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
    • B23K20/04—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating by means of a rolling mill
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/20—Bonding
    • B23K26/21—Bonding by welding
    • B23K26/24—Seam welding
    • B23K26/244—Overlap seam welding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/20—Bonding
    • B23K26/32—Bonding taking account of the properties of the material involved
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/20—Bonding
    • B23K26/32—Bonding taking account of the properties of the material involved
    • B23K26/323—Bonding taking account of the properties of the material involved involving parts made of dissimilar metallic material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2101/00—Articles made by soldering, welding or cutting
    • B23K2101/16—Bands or sheets of indefinite length
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00—Materials to be soldered, welded or cut
    • B23K2103/02—Iron or ferrous alloys
    • B23K2103/04—Steel or steel alloys
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00—Materials to be soldered, welded or cut
    • B23K2103/02—Iron or ferrous alloys
    • B23K2103/04—Steel or steel alloys
    • B23K2103/05—Stainless steel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00—Materials to be soldered, welded or cut
    • B23K2103/08—Non-ferrous metals or alloys
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00—Materials to be soldered, welded or cut
    • B23K2103/08—Non-ferrous metals or alloys
    • B23K2103/10—Aluminium or alloys thereof
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00—Materials to be soldered, welded or cut
    • B23K2103/08—Non-ferrous metals or alloys
    • B23K2103/12—Copper or alloys thereof
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00—Materials to be soldered, welded or cut
    • B23K2103/50—Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
    • B29C65/14—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation
    • B29C65/16—Laser beams
    • B29C65/1603—Laser beams characterised by the type of electromagnetic radiation
    • B29C65/1612—Infrared [IR] radiation, e.g. by infrared lasers
    • B29C65/1619—Mid infrared radiation [MIR], e.g. by CO or CO2 lasers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
    • B29C65/14—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation
    • B29C65/16—Laser beams
    • B29C65/1629—Laser beams characterised by the way of heating the interface
    • B29C65/1632—Laser beams characterised by the way of heating the interface direct heating the surfaces to be joined
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/78—Means for handling the parts to be joined, e.g. for making containers or hollow articles, e.g. means for handling sheets, plates, web-like materials, tubular articles, hollow articles or elements to be joined therewith; Means for discharging the joined articles from the joining apparatus
    • B29C65/7858—Means for handling the parts to be joined, e.g. for making containers or hollow articles, e.g. means for handling sheets, plates, web-like materials, tubular articles, hollow articles or elements to be joined therewith; Means for discharging the joined articles from the joining apparatus characterised by the feeding movement of the parts to be joined
    • B29C65/7861—In-line machines, i.e. feeding, joining and discharging are in one production line
    • B29C65/787—In-line machines, i.e. feeding, joining and discharging are in one production line using conveyor belts or conveyor chains
    • B29C65/7873—In-line machines, i.e. feeding, joining and discharging are in one production line using conveyor belts or conveyor chains using cooperating conveyor belts or cooperating conveyor chains
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/78—Means for handling the parts to be joined, e.g. for making containers or hollow articles, e.g. means for handling sheets, plates, web-like materials, tubular articles, hollow articles or elements to be joined therewith; Means for discharging the joined articles from the joining apparatus
    • B29C65/7858—Means for handling the parts to be joined, e.g. for making containers or hollow articles, e.g. means for handling sheets, plates, web-like materials, tubular articles, hollow articles or elements to be joined therewith; Means for discharging the joined articles from the joining apparatus characterised by the feeding movement of the parts to be joined
    • B29C65/7888—Means for handling of moving sheets or webs
    • B29C65/7894—Means for handling of moving sheets or webs of continuously moving sheets or webs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/01—General aspects dealing with the joint area or with the area to be joined
    • B29C66/05—Particular design of joint configurations
    • B29C66/10—Particular design of joint configurations particular design of the joint cross-sections
    • B29C66/11—Joint cross-sections comprising a single joint-segment, i.e. one of the parts to be joined comprising a single joint-segment in the joint cross-section
    • B29C66/112—Single lapped joints
    • B29C66/1122—Single lap to lap joints, i.e. overlap joints
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/41—Joining substantially flat articles ; Making flat seams in tubular or hollow articles
    • B29C66/43—Joining a relatively small portion of the surface of said articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/83—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools
    • B29C66/834—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools moving with the parts to be joined
    • B29C66/8341—Roller, cylinder or drum types; Band or belt types; Ball types
    • B29C66/83411—Roller, cylinder or drum types
    • B29C66/83413—Roller, cylinder or drum types cooperating rollers, cylinders or drums

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Mechanical Engineering (AREA)
  • Plasma & Fusion (AREA)
  • Laser Beam Processing (AREA)
  • Lining Or Joining Of Plastics Or The Like (AREA)
GB43872/76A 1975-10-24 1976-10-22 Laser welding Expired GB1562922A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US62547975A 1975-10-24 1975-10-24
US62548075A 1975-10-24 1975-10-24

Publications (1)

Publication Number Publication Date
GB1562922A true GB1562922A (en) 1980-03-19

Family

ID=27089932

Family Applications (1)

Application Number Title Priority Date Filing Date
GB43872/76A Expired GB1562922A (en) 1975-10-24 1976-10-22 Laser welding

Country Status (10)

Country Link
JP (1) JPS5260256A (nl)
BR (1) BR7607073A (nl)
DD (1) DD127457A5 (nl)
DE (1) DE2647082A1 (nl)
ES (2) ES452604A1 (nl)
FR (1) FR2328543A1 (nl)
GB (1) GB1562922A (nl)
IL (1) IL50752A0 (nl)
NL (1) NL7611748A (nl)
SE (1) SE413998B (nl)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3219252A1 (de) * 1981-05-21 1982-12-09 Lucas Industries P.L.C., Birmingham, West Midlands Verfahren und vorrichtung zum zusammenschweissen von metallteilen
DE3815068A1 (de) * 1988-05-04 1989-11-23 Bayerische Motoren Werke Ag Schweissverbindung zweier duennbleche
WO2011120667A1 (de) * 2010-03-30 2011-10-06 Li-Tec Battery Gmbh Kontaktelement für ableiter galvanischer zellen
CN110202853A (zh) * 2019-04-25 2019-09-06 吉林省中赢高科技有限公司 一种铜铝复合基材及其激光束焊接加工方法和应用
CN114951987A (zh) * 2021-02-24 2022-08-30 本田技研工业株式会社 接合装置和接合方法

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0126787A1 (de) * 1983-05-26 1984-12-05 Jan Tjaden Verfahren zum Laserschweissen und hierfür optimierter Kunststoff
JPS62267092A (ja) * 1986-05-15 1987-11-19 Sumitomo Special Metals Co Ltd クラツド板
DE3630889A1 (de) * 1986-09-11 1988-03-24 Krupp Gmbh Verfahren zum laengsnahtschweissen von behaelterruempfen mittels laserstrahl und vorrichtung zur durchfuehrung des verfahrens
GB8910302D0 (en) * 1989-05-05 1989-06-21 Welding Inst Bonding method
DE4219619C1 (de) * 1992-06-16 1994-01-27 Fraunhofer Ges Forschung Verfahren und Vorrichtung zum Fügen einer kontinuierlich geförderten stromleitenden Materialbahn
DE19502140C1 (de) * 1995-01-25 1996-05-15 Thyssen Stahl Ag Verfahren zum laserunterstützten Plattieren von Band und dessen Anwendung
DE102009003717A1 (de) * 2009-04-01 2010-10-14 Reis Gmbh & Co. Kg Maschinenfabrik Verfahren und Vorrichtung zum stoffschlüssigen Verbinden
CN109014580B (zh) * 2018-08-14 2020-06-09 哈尔滨工业大学 一种施加滚轧辅助的搭接激光间隙填粉焊方法
CN110052744A (zh) * 2019-03-18 2019-07-26 苏州领裕电子科技有限公司 大小料带平行走料焊接设备
CN110216939B (zh) * 2019-04-25 2022-02-15 吉林省中赢高科技有限公司 一种铜铝复合基材及其压力扩散焊接加工方法和应用

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT289377B (de) * 1965-08-20 1971-04-26 Windmoeller & Hoelscher Strahlungsschweißeinrichtung
GB1441067A (en) * 1974-04-16 1976-06-30 Ici Ltd Seaming process
US3974016A (en) * 1974-11-04 1976-08-10 Bell Telephone Laboratories, Incorporated Bonding of thermoplastic coated cylinders

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3219252A1 (de) * 1981-05-21 1982-12-09 Lucas Industries P.L.C., Birmingham, West Midlands Verfahren und vorrichtung zum zusammenschweissen von metallteilen
US4514613A (en) * 1981-05-21 1985-04-30 Lucas Industries Plc, Great King St. Method of an apparatus for welding together metal components
DE3815068A1 (de) * 1988-05-04 1989-11-23 Bayerische Motoren Werke Ag Schweissverbindung zweier duennbleche
WO2011120667A1 (de) * 2010-03-30 2011-10-06 Li-Tec Battery Gmbh Kontaktelement für ableiter galvanischer zellen
CN102821905A (zh) * 2010-03-30 2012-12-12 锂电池科技有限公司 用于伽伐尼电池的导体的接触元件
CN110202853A (zh) * 2019-04-25 2019-09-06 吉林省中赢高科技有限公司 一种铜铝复合基材及其激光束焊接加工方法和应用
CN114951987A (zh) * 2021-02-24 2022-08-30 本田技研工业株式会社 接合装置和接合方法

Also Published As

Publication number Publication date
FR2328543B1 (nl) 1980-08-01
ES462440A1 (es) 1978-11-16
JPS5260256A (en) 1977-05-18
FR2328543A1 (fr) 1977-05-20
NL7611748A (nl) 1977-04-26
BR7607073A (pt) 1977-09-06
SE413998B (sv) 1980-07-07
DD127457A5 (nl) 1977-09-21
DE2647082A1 (de) 1977-05-12
IL50752A0 (en) 1976-12-31
ES452604A1 (es) 1977-12-16
SE7610675L (sv) 1977-04-25

Similar Documents

Publication Publication Date Title
US4185185A (en) Laser welding
US4187408A (en) Method for laser seam welding of moving workpieces
US5502292A (en) Method for laser welding ultra-thin metal foils
GB1562922A (en) Laser welding
US4471204A (en) Method for joining of articles by energy beam and apparatus for controlling said method
KR100228252B1 (ko) 고밀도 에너지빔의 사용에 의한 강관의 제조방법
JPS6332554B2 (nl)
JP6158356B2 (ja) レーザ溶接方法及び溶接継手
US4560855A (en) Method for joining of articles by energy beam and apparatus for controlling said method
Jokinen et al. Welding of thick austenitic stainless steel using Nd: yttrium–aluminum–garnet laser with filler wire and hybrid process
CA2209804A1 (en) Method of laser beam welding of zinc-coated steel sheet
CA1085464A (en) Method for laser seam welding of moving workpieces
Iwase et al. Dual-focus technique for high-power Nd: YAG laser welding of aluminum alloys
JPH0212674B2 (nl)
Mohammed et al. Weld bead profile of laser welding dissimilar joints stainless steel
CA1084999A (en) Method for laser seam welding of moving workpieces
Shi et al. Hybrid Nd: YAG laser-MAG welding of thick section steel with adaptive control
EP1118420A2 (en) Inclined beam lap welding
Willgoss et al. Laser welding of steels for power plant
Abe et al. High Speed Welding of Thick Plates using a Laser Arc Combination System
JPH0333074B2 (nl)
JP2016049565A (ja) 対向する金属面同士の接合方法
JP2012187590A (ja) レーザ溶接鋼管の製造方法
JPS59101293A (ja) 溶接管の製造方法
DE2719186A1 (de) Laserschweissen

Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee