Acoustic vibrating element of graphite and method of manufacturing same
AssigneePioneer Electronic Corporation
InventorsTsunehiro Tsukagoshi, Teruo Tohma, Shinichi Yokozeki
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Abstract
An acoustic vibrating element, such a domed speaker diaphragm A or a phonographic pickup cantilever B, is formed by vapor deposition on an easily separable mold member 5 of tantalum or tantalum alloy when a mixture of a hydrocarbon gas and an inert gas is passed through a furnace heated to a temperature of 1150.degree. C.-1250.degree. C. at a flow rate in excess of 200 cm/min. The c-axis crystalline orientation of the resulting graphite element is substantially perpendicular to its surface, which provides a Young's modulus above 16,000 Kg/cm.sup.2.
Claims5
In a method for producing an electro-acoustic transducer comprising a vibrating member and means for vibrating the vibrating member, the improvement comprising the step of:
- introducing a mixture of a gaseous carbon compound and an inert gas and/or hydrogen into a furnace;
- subjecting said mixture to thermal decomposition to thereby deposit a layer of carbon on a surface of a mold former having a desired configuration, wherein the flow rate of said gaseous carbon compound is sufficiently high that the crystallographic c-axis of said layer of carbon is substantially perpendicular to the surface of said layer of carbon;
- separating said layer of carbon from said mold former to thus obtain said vibrating member;
- and mounting said vibrating member in a position to be vibrated by said vibrating means.
Dependencies are inferred from the claim text.