| 摘要 |
<p>The moving contact in a vacuum chamber (1) is operated by a rod (4) connected to a displacement device (5) which is driven by a conductive helical spring (6) of shape memory alloy. Excessive current on the protected line passes through the spring, producing enough heat to switch the alloy from the martensitic to the austenitic phase. An abrupt movement is executed through the dead point constituted by the longitudinal axis of the chamber. Reclosure can be effected by a sequencer (8) comprising three retractable and two non-retractable cams (81-83;84,85) and three pneumatic jacks (87-89).</p> |
