Abstract: A fiber optics condition sensor and a method of producing such a device is disclosed. A bundle of optical fibers provides a planar termination on one end and is bifurcated to provide one group adapted to be connected to a light source and another group adapted to be connected to a detector. A shallow, curved, thin metallic diaphragm provides a central portion movable toward and away from the termination in response to the condition being sensed in order to vary the light reflected to the detector and therefore produce a detector output signal which is a function of the changes in conditions being sensed. The diaphragm may be formed of bimetal for sensing temperature conditions, or of a homogeneous metal to sense pressure.

Abstract: A thermally responsive switching device suitable for use as a motor protector and the like is disclosed. Such device includes a housing assembly consisting of a thermoplastic base and a shallow drawn metallic cover. The base provides sidewalls extending to a peripheral flange against which a flange on the cover is positioned. The thermoplastic material is deformed inwardly around the cover flange to permanently connect the assembly. The switch includes an elongated bimetal snap element supported at one end on the end of a heater in heat exchange relation therewith. The other end of the heater is connected to an external terminal through an opening in the thermoplastic base. The terminal provides a tubular projection extending through the opening and a plurality of inwardly extending, resilient tabs which are welded to the heater.

Abstract: A thermal relay is disclosed which provides a bi-metal snap disc actuator system. The actuator system includes a central divider of material having relatively low thermal conductivity and a metallic disc cup mounted on each side of the central divider. A bi-metal snap disc is located in each disc cup and a separate heater is provided to respectively heat the discs. The discs are mounted so that they tend to move toward each other at normal environmental temperatures and a bumper is interposed between the discs to cause them to move in with snap action in the unison. The actuator operates two switches. In one embodiment, one switch is normally closed and the other switch is normally open. In another embodiment, both switches are normally open.

Abstract: A snap acting switch structure for thermostats or the like is disclosed in which the switch's movable contact is supported on a pair of arms the first of which is placed in compression and the second of which is placed in tension by a bistable spring system. The first arm is formed of relatively thin metal providing deep flanges to cause the arm to act as a rigid beam pivoted at one end. The two arms are welded together in face-to-face adjacency and the actuating force applied to the switch is applied substantially at the joint between the arms. Therefore, there are no substantial bending forces applied to the first arm, and the switch efficiently produces good wiping between the contacts and sufficient shear forces to break welds which may occur therebetween.

Abstract: A temperature indicator is disclosed which includes a housing providing a transparent window. A bimetal snap disc is located in the housing and is movable from a position spaced from the window to a position immediately adjacent to the window upon reaching a predetermined temperature. The housing includes an opaque fluid which obscures the face of the snap disc from view through the window when it is spaced from the window but allows viewing of the face of the snap disc when immediately adjacent to the window. A suitable indicia is provided on the snap disc which provides an indication that the snap disc has operated by being exposed to the critical temperature. The snap disc is arranged so that it remains in the operated position after being exposed to the critical temperature involved.