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US 7,024,015 B2Granted
Speaker and method of manufacturing the speaker
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsAkinori Hasegawa, Fumiyasu Konno
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Abstract
The speaker disclosed in this invention comprises: (a) a central cap fixed on voice coil bobbin; (b) a shaft fixed in the center of the central cap; and (c) a bearing filled with lubricating fluid and fixed in a through-hole disposed in the center of a magnetic circuit. The speaker has excellent characteristics without sliding noise or harmful rolling phenomena but with reduced harmonic distortion due to the introduction of a magnetic fluid or a lubricant used as a lubricating fluid.
Claims20
A speaker comprising:
- (a) a magnetic circuit having a through-hole provided in a center thereof;
- (b) a frame fixed to said magnetic circuit;
- (c) a diaphragm fixed to said frame;
- (d) a bobbin having a wound voice coil housed on internal circumference of said diaphragm;
- (e) a central cap fixed to said bobbin;
- (f) a shaft fixed in the center of said central cap and further protruding toward a front of said diaphragm;
- and
- (g) a bearing fit in said through-hole,
- wherein said shaft fits in said bearing with a clearance, and lubricant is held between said bearing and said shaft.
6 more elements
Dependencies are inferred from the claim text.