| 摘要 |
534,767. Piezo-electric crystal mountings. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. Nov. 28, 1939, No. 31012. Convention date, Nov. 28, 1938. [Class 40 (v)] A mount for a piezo-electric crystal C includes two electrode plates P formed at the corners with risers R1 - R1 which are adapted to clamp the crystal near the edges. The centres of plates P are formed with raised electrode parts E, the distances of which from the crystal faces can be varied by varying the clamping force, the plates P being sufficiently flexible, Fig. 4 shows a crystal assembly mounted in a plug type holder of the kind described in Specification 459,645. The clamping force is provided by resilient arms A1, A2 and may be varied by means of a screw S. In a modification, Fig. 3 (not shown), the electrode E is formed by a central metallic insert in an insulating clamping plate, thus reducing inter-electrode capacity at high frequencies. |
