Global Patent Index - EP 0507655 A1

EP 0507655 A1 19921007 - Method of production of a diaphragm with high internal loss and high rigidity for an electrodynamic loudspeaker.

Title (en)

Method of production of a diaphragm with high internal loss and high rigidity for an electrodynamic loudspeaker.

Title (de)

Verfahren zur Herstellung einer Membran eines elektrodynamischen Lautsprechers mit hohem Innenverlust und grosser Steifigkeit.

Title (fr)

Procédé de fabrication d'une membrane de haut-parleur électrodynamique à pertes internes élevées et à grande rigidité.

Publication

EP 0507655 A1 19921007 (FR)

Application

EP 92400840 A 19920326

Priority

FR 9103786 A 19910328

Abstract (en)

Method of production of a diaphragm with high internal loss and high rigidity for an electrodynamic loudspeaker, characterised in that a die is formed, having the shape required for the diaphragm, by cold compression of expanded graphite flakes in a graphite mould, and then in that this die is later stiffened by forming, at least at the surface, compounds of high specific modulus deposited in dense layers.

IPC 1-7

H04R 7/02; H04R 7/10; H04R 31/00

IPC 8 full level

H04R 7/02 (2006.01); H04R 7/10 (2006.01); H04R 31/00 (2006.01)

CPC (source: EP)

H04R 7/02 (2013.01); H04R 7/10 (2013.01); H04R 31/003 (2013.01)

Citation (search report)

  • [X] DE 3917006 A1 19901206 - MITSUBISHI PENCIL CO [JP]
  • [X] FR 2649275 A1 19910104 - MITSUBISHI PENCIL CO [JP]
  • [X] PATENT ABSTRACTS OF JAPAN vol. 3, no. 143 (E-154)27 Novembre 1979 & JP-A-54 121 726 ( HITACHI LTD )
  • [X] PATENT ABSTRACTS OF JAPAN vol. 12, no. 397 (E-672)21 Octobre 1988 & JP-A-63 138 900 ( MITSUBISHI PENCIL CO LTD )
  • [X] PATENT ABSTRACTS OF JAPAN vol. 6, no. 180 (C-125)14 Septembre 1982 & JP-A-57 095 823 ( MATSUSHITA ELECTRIC IND CO LTD )
  • [A] PATENT ABSTRACTS OF JAPAN vol. 5, no. 55 (E-52)16 Avril 1981 & JP-A-56 006 596 ( PIONEER ELECTRONIC CORP )
  • [A] PATENT ABSTRACTS OF JAPAN vol. 10, no. 79 (E-391)28 Mars 1986 & JP-A-60 224 397 ( ONKYO KK )
  • [A] PATENT ABSTRACTS OF JAPAN vol. 14, no. 55 (E-882)31 Janvier 1990 & JP-A-01 279 699 ( MITSUBISHI ELECTRIC CORP )
  • [A] PATENT ABSTRACTS OF JAPAN vol. 5, no. 192 (E-85)8 Décembre 1981 & JP-A-56 114 496 ( PIONEER ELECTRONIC CORP )

Designated contracting state (EPC)

DE ES FR GB IT SE

DOCDB simple family (publication)

EP 0507655 A1 19921007; FR 2674718 A1 19921002

DOCDB simple family (application)

EP 92400840 A 19920326; FR 9103786 A 19910328