| 摘要 |
A retaining mechanism for an externally threaded part or element which can release without exerting a shock load to the structure which it assembles. The retaining mechanism has a spring biased shiftable ring which retains three threaded nut segments by peripheral surface contact on aligned external cylindrical surfaces of the segmented nut. The retained threaded nut segments maintain threaded engagement with a threaded part to form an assembly. The threaded segments are distanced from the assembled structure by a column of Titanium-Nickel shape memory alloy (SMA) material that has been pre-worked to an increased length at a temperature below its transition temperature from face-centered to body-centered structure so that the column will shrink in length upon the application of heat. A heating element is incorporated within or about the SMA column. Preload induced in the assembled threaded part and the assembled structure is relieved by heating of the SMA column which allows the SMA material shrink to its original length thus relieving the preload of the assembled part and structure. The relief of preload in turn allows the spring-biased load retainer ring to move out of engagement with the threaded nut segments. The assembled structure may thereafter gently separate when abrupt separable forces are exerted.
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