| 摘要 |
A speech transmitter for use in gas masks and the like comprises a body member having a central, circular recess in one end thereof and a marginal rim surrounding the recess, a cover member having a complementary central, circular recess in one end thereof and a marginal rim surrounding the recess, the cover member marginal rim being lockingly engageable with the body member marginal rim so as to form an unitary assembly in which the body recess and the cover recess are in coaxially aligned, face-to-face relation and define a membrane chamber, the marginal rims having mating surfaces adapted to secure and radiallytension a membrane therebetween; and a membrane having a marginal edge interposed between the mating surfaces and a main body portion disposed within the membrane chamber. |
