Abstract: In apparatus wherein a massive component, such as the spot film device of an x-ray table, is driven to various positions with an electric motor drive, a handle is attached to the component for urging it in the desired direction. The handle is attached to the component with beams that flex slightly. A piezoresistive strain gage assembly is mounted on one of the beams for developing an error signal in response to the handle being urged in either direction. The signal is amplified and used to control the power assist driving motor. Means are provided for compensating the vertical component of gravitational force when the handle and the object to which it is attached are angulated. Means are also provided for disabling the drive motor if an electronic element fails.

Abstract: In a spot film device, the inner and main carriages for a film cassette are positioned with reversible servo motors. An x-ray grid is mounted on the bottom of the main carriage and a cross grid is mounted on tracks beneath the carriage such that the cross grid may be used or not used for fluoroscopy and both grids may be used for radiography. Field defining masks are also mounted for translating selectively with the carriage. Individual reversible servo motor drives are used to advance and retract the masks and cross grid. Means are provided for absorbing shock or negating drive system momentum when the masks or grid are stopped abruptly. Reduced power is applied to the mask and grid drive motors when the masks and grid reach their stops for holding them against their stops. A motor driven palpator cone, having unique driving and locking means is provided. Means are provided for loading and unloading cassettes from either the front or rear of the spot film device.

Abstract: In a spot film device, the inner and main carriages for a film cassette are positioned with reversible servo motors. An x-ray grid is mounted on the bottom of the main carriage and a cross grid is mounted on tracks beneath the carriage such that the cross grid may be used or not used for fluoroscopy and both grids may be used for radiography. Field defining masks are also mounted for translating selectively with the carriage. Individual reversible servo motor drives are used to advance and retract the masks and cross grid. Means are provided for absorbing shock or negating drive system momentum when the masks or grid are stopped abruptly. Reduced power is applied to the mask and grid drive motors when the masks and grid reach their stops for holding them against their stops. A motor driven palpator cone, having unique driving and locking means is provided. Means are provided for loading and unloading cassettes from either the front or rear of the spot film device.

Abstract: In a spot film device, the inner and main carriages for a film cassette are positioned with reversible servo motors. An X-ray grid is mounted on the bottom of the main carriage and a cross grid is mounted on tracks beneath the carriage such that the cross grid may be used or not used for fluoroscopy and both grids may be used for radiography. Field defining masks are also mounted for translating selectively with the carriage. Individual reversible servo motor drives are used to advance and retract the masks and cross grid. Means are provided for absorbing shock or negating drive system momentum when the masks or grid are stopped abruptly. Reduced power is applied to the mask and grid drive motors when the masks and grid reach their stops for holding them against their stops. A motor driven palpator cone, having unique driving and locking means is provided. Means are provided for loading and unloading cassettes from either the front or rear of the spot film device.