| 摘要 |
<p>A speech transmitter (10) for use in gas masks and the like comprises a body member (12) having a central, circular recess (14) in one end thereof and a marginal rim (16) surrounding the recess (14), and a cover member (22) having a complementary central, circular recess (24) in one end thereof and a marginal rim (26) surrounding the recess. The cover member (22) marginal rim (26) is lockingly engageable with the body member marginal rim (16) so as to form a unitary assembly in which the body recess (14) and the cover recess (24) are in coaxially aligned, face-to-face relation and define a membrane chamber (30). The marginal rims (16, 26) have mating surfaces (46, 80) adapted to secure and radially tension a membrane (32) between them. The membrane (32) has a marginal edge (34) interposed between the mating surfaces (46, 80) and a main body portion (36) disposed within the membrane chamber (30).</p> |
