Abstract: A detector for detecting hot wheels or bearings on a railroad car includes an infrared sensor supported within a detector by a sensor housing. Elastic balls are disposed in the housing to absorb shocks generated by a train passing the detector.

Abstract: The present invention relates to a shutter mechanism including a shutter adapted to rotate 45.degree. from closed to open positions and which is self locking in both positions.

Abstract: An improved heat sensing tip for a temperature sensing device is provided. The tip comprises an elongated shell of heat conductive material. A temperature probe is positioned for movement within the shell toward and away from an opening in the shell. A cap of heat conductive material is positioned at the front of the probe. A spring urges the cap in contact with the shell for heat conductivity between the two when the device is not in operation. When the device is in operation, the spring bias is overcome thereby providing an insulating air gap between the shell and the tip.

Abstract: A device to simulate the rolling of a hypothetical wheel along a path is provided. The device includes a wheel sector mounted to one end of a rotor. A drive is provided for rotating the rotor in one direction and the sector in the opposite direction so that the sector remains substantially tangent to a line segment. The wheel sector is driven by a pulley the diameter of which is one-half that of a drive pulley rotated with the rotor.

Abstract: A jogging switch mechanism is provided for a potentiometer which permits the potentiometer shaft to be rotated either clockwise or counterclockwise and then, upon release, to return automatically to a very accurately centered neutral position. The neutral position may be an "off" position by positioning micro switches in the path of travel of the switch mechanism.