Global Patent Index - EP 0974984 A1

EP 0974984 A1 2000-01-26 - Manufacture of varistors

Title (en)

Manufacture of varistors

Title (de)

Herstellung von Varistoren

Title (fr)

Production de varistors

Publication

EP 0974984 A1 (EN)

Application

EP 98650042 A

Priority

  • EP 98650042 A
  • IE S980588 A

Abstract (en)

Varistors (46) having a multiphase composition, such as zinc oxide varistors are produced by the cold pressing technique. A binder is introduced into the slurry (5), and the slurry is spray dried (10) to form a powder (11). The powder is conveyed to pressing heads (41) through a heater (23) having heating baffles (26) extending inwardly and downwardly to provide a cascading action as the powder. The baffles (26) uniformly heat the powder to a temperature above the glass transition temperature of the binder by approximately 30 DEG C. The powder and binder is then much more pliable as it is being compressed, resulting in a less brittle pressed disc. This achieves a reduced defect rate. <IMAGE>

IPC 1-7 (main, further and additional classification)

H01C 7/112

IPC 8 full level (invention and additional information)

H01C 7/112 (2006.01); H01C 17/30 (2006.01)

CPC (invention and additional information)

H01C 7/112 (2013.01); H01C 17/30 (2013.01)

Citation (search report)

  • [A] EP 0196370 A1 19861008 - BBC BROWN BOVERI & CIE [CH]
  • [AD] US 5004573 A 19910402 - OH MYUNG H [KR], et al
  • [Y] DATABASE WPI Section Ch Week 7805, Derwent Publications Ltd., London, GB; Class L02, AN 78-09562A, XP002086531
  • [Y] YODOGAWA M: "Zinc oxide varistors provide urgent surge control", JEE (JOURNAL OF ELECTRONIC ENGINEERING), AUG. 1987, JAPAN, VOL. 24, NR. 248, PAGE(S) 76 - 81, ISSN 0385-4507, XP002086530
  • [A] PATENT ABSTRACTS OF JAPAN vol. 096, no. 003 29 March 1996 (1996-03-29)

Designated contracting state (EPC)

AT DE DK ES FR GB GR IE IT NL PT SE

EPO simple patent family

EP 0974984 A1 20000126; EP 0974984 B1 20061004; IE S80693 B2 19981202; IE S980588 A2 19981202

INPADOC legal status


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