| 摘要 |
889,544. Electromagnetic relays. BENDIX CORPORATION. Aug. 24, 1959 [Sept. 10, 1958], No.28876/59. Class 38 (5). A bridging contact which is insensitive to vibration is normally held against a first pair of fixed contacts by a strong spring acting against a weaker spring and is moved away from the first contacts, to engage a second pair of fixed contacts, by the weaker spring when the strong spring is rendered inoperative by operating means. In the electromagnetic relay shown the fixed contact pairs 30, 31 and 36, 36 are secured in an insulating plate 20, preferably of sintered glass, and the bridging contact is a circular disc 37 movable on a stem 39 also secured to the plate 20. A strong spring 41 acts between the head 42 of the stem 39 and an insulating sleeve 44 and urges the sleeve, a rocking washer 45 and the disc 37 against the fixed contacts 30, 31. When the armature 46 engages flanges 47 on the sleeve 44 and moves it downward so that the force of the spring 41 no longer acts on the disc 37, the latter is moved downward by a weaker spring 40 until it bridges contacts 35, 36. The circular armature 46 operates four contact sets and is normally biased away from the poles 17, 18 of the electromagnet by a spring 56 so that the head 54 of a pin 49, secured to the centre of the armature, is centred in a sleeve 50 secured to the plate 20. The coil 15 has a core 16 carrying the pole 18 and is enclosed in a magnetic case 14 in which the annular pole 17 fits. The annular gap between the poles 17, 18 is recessed at 52 to accommodate the lower ends 42 of the stems 39. The case 14 is welded to a metal ring 19 in which the plate 20 is formed and the assembly may be sealed after evacuation and filling with an inert gas through a tube 57. |
