| 摘要 |
<p>1. Miniature electric circuit breaker with moulded casing comprising : - a cut off chamber (30) enclosed by two electrodes (38, 40) to guide the arc, disposed to pick up an arc drawn between contacts (20, 22) when they get separated, - an electromagnetic trip device (28) having a coil (68) and a plunger (74) controlling a release latch (58) when a fault occurs to induce the automatic opening of said contacts (20, 22), - an actuation rod (80) coupled to the plunger (74) and acting on a rotating moving contact (20) to accelerate the shift of the moving contact (20) toward the opening position when the coil (68) of said trip device (28) is excited, - and a sleeve (70) to guide in translation the plunger (74), characterized in that said plunger (74) presents a general form of a barrel or a rib accommodating gaps for the compressed air passage by the piston effect generated when the plunger (74) moves quickly inside the sleeve (70) and allowing a limited motion of the plunger rotation inside the sleeve (70) during the opening travel of the rotating moving contact (20).</p> |
