| 摘要 |
790,958. Electromagnetic relays; mercury contact members for switches; electrostatic switches. WESTERN ELECTRIC CO., Inc. Feb. 17, 1956 [Feb. 18, 1955], No. 5012/56. Class 38 (5). A mercury container 19 has a cupshaped portion 21, a plate 20 and a cover 23, the surfaces 21a, 20a and 23a of which are formed from a material which is wettable by mercury. The plate 20 has a bent-back portion 22 having an aperture so that the mercury 25 forms a meniscus in said aperture for engagement by a movable contact consisting of a tungsten core 18 and chromium covering 17, the core 18 protruding slightly below the covering 17. Since tungsten is wettable by mercury and chromium is not, make and break between the core 18 and mercury 24 is simplified, whereas the part 17 serves to damp the motion of the contact. The construction of the container is said to be such that it is difficult to remove the mercury by inversion of the container or by jarring. The mercury contact may form part of an electromagnetic relay, Fig. 1, having magnetic electrodes 12, 13, and a resilient armature 15 attached to electrode 12. A non-magnetic plate 26 secured to electrode 13 carries a container 19 and a magnetic extension 27. On energization of a coil 56 surrounding the envelope 11, which may be gas-filled, the armature is repelled by electrode 12 and attracted by electrode 13, so that contact 18 engages the mercury. On deenergization, the resilience of the armature restores the parts, vibration of the armature being prevented by a bent blade spring 16, or a flat blade spring (Fig. 6, not shown). In a modification (Fig. 7, not shown) the blade spring is replaced by a coil surrounding the electrode 12 and connected thereto at each end, and in Fig. 8 (not shown) the contacts are normally closed. In a transfer switch Fig. 9, a common electrode 41 carries a pivot 46 on which is a roller 47 to which the armature 49 and a blade spring 48 are secured, the other end of the spring 48 being fixed at 45. The armature 49 carries two movable contacts 50, 51 co-operating with mercury containers 52, 53, the latter being inverted. Magnets may be associated with the actuating system to provide polarized operation. The moving contact may be operated by electrostatic means. |
