Patent ID: 8900097

Claim:
An apparatus for delivering an assist force to user moved weights of an exercise or rehabilitation weight machine or stand comprising: an assist assembly including a servo motor with integrated closed loop feedback configured for selective angular position and torque control, a transmission having one input shaft connected with the servo motor and one output shaft; and a reel fixed to the output shaft of the transmission; a flexible assist member having first and second opposing ends, the first end being at least securable to the reel so as to permit the member to be wound onto or from the reel by operation of the servo motor and the second end being configured to be coupled directly or indirectly with the user moved weights; a human-machine interface to provide human input of variable parameters for assistance control including entry of at least a user selected non-zero assist force; a servo motor drive; and a main digital controller operably connected with at least the servo motor, the servo motor drive and the human-machine interface, the main digital controller being preprogrammed to convert the entered selective assist force into control signals sent to the servo motor drive to selectively control power provided to the servo motor to generate the selected assist force at the flexible assist member during a concentric movement portion of an exercise repetition having consecutive concentric and eccentric movement portions.