Abstract: A garage door operator includes a drive screw, rotationally and longitudinally movable in a shuttle track or guide rail, and a screw-driven shuttle mounted on the track and connected to the door. A lever arm is attached to the screw at a rearward end thereof and is pivoted to the operator at one side of the screw. Another end of the lever arm, adjacent an opposite side of the screw, is operatively disposed with respect to control switches and is spring-loaded, whereby door engaged obstructions cause the rotating screw to move longitudinally, against the spring bias, and to actuate, through the lever arm, a switch for stopping or for reversing the operator motor. A sleeve coupling permits longitudinal screw movement with respect to the operator's motor, and is provided with means to permit continued motor operation, drivingly disengaged from the screw, upon control malfunction, in order to prevent damage or injury.

Abstract: A monitoring system for motor vehicles that produces a warning signal when the pressure within a tire changes to an unacceptable pressure. The system includes a sensor unit attached on the wheel on which the tire to be monitored is mounted and a second component secured to the vehicle body. The unit mounted to the vehicle body contains a coil wound on a core that is positioned at a location so that as the wheel of the vehicle revolves a second coil wound on a core that forms a part of the sensor unit comes into close proximity to the coil secured to the vehicle body during each rotation of the wheel. When the pressure in the tire changes from a "normal" pressure, a harmonious balance between the two components of the system is disturbed resulting in the triggering of a warning mechanism that alerts the operator of the vehicle that the air pressure in the tire has reached an unacceptable level.

Abstract: A monitoring system for detecting a longitudinal rip in a conveyor belt senses the presence of the rip and simultaneously produces a warning signal and stops the operation of the conveyor system. The system includes a series of sensor circuits embedded in the conveyor belt in spaced relationship along the length of the belt and a series of alarm circuits positioned at intervals along the upper run of the conveyor belt but out of actual contact with the conveyor belt. Each sensor unit embedded in the conveyor belt consists of a loop of conductive wire or ribbon positioned transversely across substantially the width of the conveyor belt and a coil wound on a powder core with its terminals in electrical connection with the ends of the loop of conductive wire or ribbon. When the conveyor belt is free of longitudinal rips, the sensor circuit as it passes in close proximity to the alarm circuit has no noticeable effect on the alarm circuit.