Nova Patents
US3665352A

Permanent magnet system for a loudspeaker

Abstract

A permanent magnet system is made for a loudspeaker consisting ofa rodorring-formed axial magnetic magnets and soft iron parts. A portion ofthe ferromagnetic circuit in the system is made from a mechanically machinable, dense alloyed ferritic steel with higher electrical and lower magnetic resistance than soft iron and a saturation magnetism at least equal to the air gap induction required by the system.

Term

Term ended

Expired 23 May 1989, 37.3 years ago.

  1. Priority and filed
  2. Granted
  3. Expired
  4. Today

Every citation, both ways

Citations
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CN107948802ACited byChinaSearch report
US2003190051A1Cited byUnited States of AmericaPre-grant
US7167573B2Cited byUnited States of AmericaApplicant
US6847726B2Cited byUnited States of AmericaSearch report
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JPS54159218ACited byJapanSearch report
EP0632676A1Cited byEuropean Patent Office (EPO)Search report
US2003190052A1Cited byUnited States of AmericaPre-grant
US5701657ACited byUnited States of AmericaSearch report
US3867587ACited byUnited States of AmericaSearch report
US5070530ACited byUnited States of AmericaSearch report
JPS54128729ACited byJapanSearch report
US4289937ACited byUnited States of AmericaSearch report
US6768806B1Cited byUnited States of AmericaSearch report
CN102045626ACited byChinaSearch report