摘要 |
An apparatus is disclosed which is adapted to statically or intermittently apply a traction force to the body of a patient for therapeutic purposes. The apparatus includes a novel control means for cyclically reversing the direction of rotation of the wind-up drum upon predetermined minimum and maximum forces being present in the tension cord, and wherein the actual tension in the cord is monitored by a control circuit which provides an electrical output which is linearly proportional to the tension. The output signal is fed to a comparator circuit, where it is compared with independently selectable signals representing minimum and maximum tension forces, to control the wind-up and wind-down of the cord on the drum. The tension monitoring control circuit, and the controls for selecting the minimum and maximum forces, each incorporate a transducer, and a monitoring circuit is provided for detecting the failure of any one of the transducers and thereby precluding the continued operation of the drum in the wind-up direction to a dangerous force level.
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