| 摘要 |
<p>930,987. Gas-blast switches. COQ N. V. Jan. 23, 1962 [Jan. 24, 1961], No. 2498/62. Class 38 (5). A contact opening piston of a " temporarily opened " type circuit-breaker has initial " lost motion " and is associated with means which limit the area of the piston which is subjected to the operating gas pressure in its rest position. As shown, the moving contact 3 is biased by a spring 20 against a fixed nozzle contact 1 and the piston 10 is biased by spring 12 so that an annular V-shaped projection 11 on the piston face engages an elastic ring 13 so as to divide the space between the piston and the lower end of the cylinder 6 into two parts 14, 15 of which only the part 14 is connected to the chamber 17 by passages 16. The upper port 23 of the cylinder 6 is vented to the atmosphere and a by-pass passage 22 connects the space 15 to the space 23. When gas applied through a passage 18 reaches a predetermined value the piston 10 will move upward closing the passage 22 and the gas pressure will then act on the whole lower face of the piston to urge it upwards into driving engagement with a collar 21 on the moving contact carrying pin 5. Specification 606,860 is referred to.</p> |
