| 摘要 |
A moving contact (12), spring-loaded (17) to 'open', has an arm which engages (37) a hooked link (23) on a sliding pivot (24). Its slides (25), formed directly in a breaker-box (10) structure, have mid-point check projections (36), and a release lever (33) with similar slides (31) and checks (32) links the pivot (24) and the breaker handle's shaft (15). On closure, the handle (11) moves the pivot (24) along the slides (25,31) by means of a spring link (40) which extends when the checks (32,36) are reached. When pivot, shaft, and link attachment (48) align, a rapid over-TDC action causes the latter to deflect the release lever (33) and snap the moving contact (12) to 'closed'. Magnetic (66) and thermal (80) trips operate on a projection of the release lever (33). Movement produced reverses the closure action and pushes (61,63) the moving contact (12) to 'open' as the hook (23) releases it. ADVANTAGE - Ensures positive top-dead-centre characteristic which occurs well before contact closure, thus preventing arcing, and rapid action is ensured when opening under manual or trip conditions.
|
