Leg press

摘要

A leg press machine that provides an increasing resistance curve which approximates the strength curve of a user. The machine has a weight stack that can move relative to a frame. The machine also has a push plate that is coupled to the weight stack by a cable which is guided and held in tension by a series of pulleys. The push plate is attached to a first linkage arm which is pivotally connected to a second linkage arm and a third linkage arm. The second and third linkage arms are pivotally connected to the frame, so that the push plate can rotate between a rest position and an extended position. Attached to the third linkage arm is a first rotating pulley that moves through an arc when the push plate moves between the rest and extended positions. The cable is coupled to the first rotating pulley, so that when the push plate moves toward the extended position, the arcuate motion of the pulley pulls the cable and lifts the weight stack. The linkage arms and pulley are assembled so that each successive displacement of the push plate and pulley, produces an incremental movement of the weight stack that is greater in length than the preceding incremental movement of the weight stack.