发明名称 Magnetic system for a stereo pick-up with a movable coil
摘要 PCT No. PCT/DK86/00127 Sec. 371 Date Jul. 17, 1987 Sec. 102(e) Date Jul. 17, 1987 PCT Filed Nov. 18, 1986 PCT Pub. No. WO87/03157 PCT Pub. Date May 21, 1987.In a stereo pick-up having movable coils (14) and an SmCo magnet (22) with a high energy content, with the coil system (14, 15, 18) arranged in front of one pole face of said magnet, a yoke plate (23) of a magnetic soft material is arranged in front of said system to increase the magnetic induction in the coils. The great coercive force of the magnet is utilized for simplifying and reducing the costs of the mechanical structure in that the yoke plate is formed with two legs (26) which extend rearwardly, engage and are secured to two opposite sides of the magnet. The short-circuit of the magnet established by these legs has no noticeable impact on the induction in the air gap because of the high coercive force of the magnet. The manufacturing costs of the magnet system are additionally reduced in that, instead of a hole to receive a mounting assembly (16) for the coil system, the magnet, whose material is very hard, is formed in its underside with a slot (30) in whose bottom the mounting assembly is arranged and secured by means of a plate-shaped projection (31) on a casing member (32) of plastics.
申请公布号 US4884262(A) 申请公布日期 1989.11.28
申请号 US19870078524 申请日期 1987.07.17
申请人 ORTOFON MANUFACTURING A/S 发明人 LARSEN, JAN;GUDMANDSEN, ROBERT;WINFELD, PER
分类号 H04R9/12;H04R9/16 主分类号 H04R9/12
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