Concave diaphragm for electro-acoustic transducer

Claim 1

An electro-acoustic transducer, comprising a source of oscillatory current; driving means connected to said source, including a magnetic core, and at least one winding around said core; a diaphragm of magnetic material suspended so as to establish a concave configuration as the normal or neutral point for operation in response to said source of oscillatory current, the center of said diaphragm being adjacent one end of said core so as to define an air gap, said diaphragm being responsive to said driving means to produce an audible signal; a casing for said transducer, said casing including a lower housing and a cover, and means on said lower housing and said cover for cooperatively mounting said diaphragm at its periphery, said means for cooperatively mounting said diaphragm including a flange, at the rim of said lower housing, inclined downwardly from the horizontal toward the center of the housing and at an angle of approximately 10°, and an inclined section in said cover which abuts the said flange and which is formed likewise at an angle of approximately 10° from the horizontal, thereby to hold the diaphragm between said flange and said inclined section in said cover so as to force the diaphragm into the aforesaid concave configuration, said diaphragm remaining in said concave configuration but being free to move in its entirety above said neutral point due to the lack of any restraining mechanical force imposed upon the diaphragm at or near its center.