Abstract:
A thermostatic actuator for imparting displacement to mechanical linkages and the like, having particular utility aboard spacecraft and characterized by the utilization of a rectilinearly reciprocating, spring-biased output shaft operatively coupled with a stack of superimposed individual bimetal disc members and a selectively operable electric heater including a resistance coil associated therewith adapted to heat the stack for achieving distortion of the individual disc members and an elongation of the stack to cause the output shaft to be axially extended against the bias of the spring and a bimetal latch coupled with the shaft adapted to latch the shaft against axial extension, at a first temperature, and to release the shaft for an extending displacement at elevated temperatures, whereby the actuator is selectively driven by energizing the heater.
Abstract:
An indexing mechanism for an electron beam tube having many electron guns arranged on a turret, which rotates the turret to replace the gun being used when it fails, and to rotate the turret to serially activate the cathodes of the guns during construction of the tube. One indexing apparatus employs an indexing wheel fixed to the turret, a stack of bimetallic washers, and a heater for making the washers buckle to move a pawl member toward the indexing wheel to advance it. Another indexing apparatus includes an indexing wheel fixed to the turret, a thermal motor that can rotate a shaft, a latch arm on the shaft that pivots out of engagement with the indexing wheel during the first few degrees of shaft rotation, and a pair of driving members that rotate the wheel after the latch arm disengages from it.
Abstract:
An electrically powered actuator for providing a rotational or large linear motion, which is simple and highly reliable, including a bi-metallic strip with a slot extending along its length from one end to a position near the opposite end. In a rotational actuator, the strip is bent into a spiral, with the inner turn fixed to the shaft which is to be rotated and the outer turn fixed to a support and connected to electrical leads. Current passed through the leads and through the slotted strip heats it to make it uncoil or to make it coil further, the several rotations of the strip resulting in a large rotation of the shaft.