Therapeutic traction apparatus

In a therapeutic traction applying apparatus adapted to intermittently apply a traction force to the body of a patient, and comprising a rotatably mounted drum, a length of cord having one end wound upon said drum and an opposite end adapted to be affixed to a traction appliance positioned on a patient, power means for rotating said drum in either direction to thereby selectively either wind-up or wind-down the cord on said drum, and control means for cyclically reversing the direction of rotation of said drum upon predetermined minimum and maximum forces being present in said cord, the improvement wherein said control means comprises

• means for continuously monitoring the tension in said cord and for generating an electrical output signal (Eo) which is linearly proportional to such tension,
• first force controlling means for generating an electrical output signal (Emax) representing a desired maximum tension in said cord,
• second force controlling means for generating an electrical output signal (Emin) representing a desired minimum tension in said cord, and
• comparator circuit means for cyclically connecting said power means for rotation of said drum in the wind-up direction upon Eo equaling or being less than Emin, and connecting said power means for rotation of said drum in the wind-down direction upon Eo equaling or exceeding Emax.