General Electric Company

James J Kandler

Gregory D Schwehr

Richard T Brandt

Peter H Basler

An X-ray table having an elevator mounted on a base for vertical movement, an intermediate support mounted on the elevator for moving longitudinally, and a carriage with a patient cradle on it for moving longitudinally on the support. A pair of gas springs mounted at the forward end of the table provides a constant upward force to compensate for weight of the elevator and the cantilevered load which is exerted as the patient cradle is extended in the longitudinal direction. There are individual servomotors for driving the support and the cradle. The intermediate support drive includes a drive bar and switch assemblies for sensing any force of more than 25 lbs., for example, exerted on the patient or patient cradle and for disengaging the servodrives in response thereto. The cradle drive incorporates a zero-backlash longitudinal friction drive which includes a harmonic drive unit to achieve accurate positioning of the patient. An encoder is driven by a closed-loop cable attached to the patient cradle to accurately indicate its position and speed even though there is a two-stage drive.

Patient-positioning X-ray table

A laminated touch switch panel includes a lowermost insulating board having foil contacts on its top surface and a perforated uppermost board having foil contacts on its bottom surface. A perforated insulating spacer sheet has its bottom surface interfacing with the top of the lowermost board and its upper surface interfacing with an intervening flexible perforated membrane. The membrane has foil contacts on its upper surface which are normally closed with respect to the contacts on the bottom of the uppermost board and has contacts on its lower surface which are normally open with respect to the contacts on the lowermost board. Flexing the membrane with a force applied through the uppermost board opens the normally closed contacts and closes the normally open contacts. In one embodiment, contacts are kept normally closed with resilient elements that apply a force on the membrane which is overcome to open the contacts by applying a force through an aperture in the uppermost board.

Growing community of inventors

Milwaukee, WI, United States of America

James J Kandler