| 摘要 |
1,146,132. Piezo-electric transducers. VIBRO-METER A.G. Nov.13, 1967 [Nov. 16, 1966], No.51440/67. Heading G1N. A Piezo-electric transducer element is supplied with a pre-stress by a main spring and an auxiliary spring attached in such a way that it only becomes effective when the initial pre-stress is reduced. As shown Fig. 2, a Piezo-electric element 2, used as an accelerometer, and an intermediate body 3, forming a seismic mass, are enclosed in a sleeve 12 which is axially elastic and has a solid end-cap 13, the open end of the sleeve being sealed to the mounting 1 to produce a pre-stress on the element 2. A circumferential recess 15 is cut in the end-cap 13, and one of the mating surfaces 16, 18 is chamfered. The initial pre-stress forces these surfaces into contact, but if the sleeve 12 is subjected to e.g. thermal expansion the main pre-stress is reduced but the recessed lip 17 produces the required additional stress. |
