Abstract: An inherently mechanically bistable self-supporting blade element for actuating snap-action switches, circuit breakers and devices, and methods and apparatus for producing such elements. The elements are formed from initially flat, unstressed spring material, and comprise two outer legs and a bridging portion integrally connecting them. By progressive coplanar relative displacement of the outer legs the bridging portion is deflected normally to the nominal plane of the element. Detection of this deflection enables attachment together of the outer legs to form a calibrated, inherently bistable blade element.

Abstract: A snap acting switch comprising an elongate cantilever mounted spring member having a contact portion, an electrically conductive element upon which the contact portion bears, and an actuator having surfaces intersecting at an angle, one of the surfaces bearing on the spring member. The switch is actuated by causing the spring member to approach and pass over the intersection of the surfaces, which causes the bearing pressure of the contact portion to increase before the snap action occurs.

Abstract: A snap-acting mechanism such as a switch is constructed with a generally planar blade assembled between mutually spaced portions of a pair of members forming a base. The base includes means extending from one of the portions to the other which operate to stress the blade with precision to render it mechanically bistable as a result of the process of assembling the parts of the mechanism.

Abstract: Disclosed are a switch structure and a calibration technique that facilitate the rapid and substantially automatic calibration of a switch of the type that responds to changes in an environmental parameter (e.g., a thermostatic switch). An abutment member (which will serve as the calibrated stop) is supported for preliminary movement with a switch movable member (e.g., a bimetallic arm) and is supported in a bracket which is capable of gripping the abutment member but which is initially prevented from doing so by the action of a member that stresses the bracket. The last-mentioned member is deformable (e.g., it melts) at a desired value of the environmental parameter, thereby resulting in the bracket gripping the abutment member (which then defines a stop for the switch's movable member).

Abstract: An ambient-compensated, current-actuated circuit breaker, adapted to be miniaturized. In one embodiment, the device has a movable spring arm with contact portion mounted on a base; a plural-legged, current sensitive monometallic element is mounted on the base with the legs joined at an upper end and spread apart to form a rigid structure, the current-sensitive element having a combined contact and latch portion at one end which engages the spring arm in a contact-closed position, the force of the spring arm being in a direction in which the current sensitive element is rigid. Upon heating a proper one or more of the legs by electrical current, the heated leg or legs elongate and move the upper end portion and latch portion in a direction to release the spring arm and open the contacts. An equal change in temperature of all the legs will not trip the latch.