Calf isolating exercise machine

Claim 1

A calf exercising machine, comprising: a rigid frame which includes means for supporting an operator in a seated position of operation; a rigid rotating foot-engaging assembly which is journaled in said frame an axis which is approximately common with the axes of rotation of said operator's ankle joints while said operator is supported in said machine's frame in the operating position; said rigid rotating foot-engaging assembly includes ball-of-the-foot-engaging surfaces which, through body-machine contact, apply resistive force to the balls of the operator's feet through circular exercise movement paths about the rotational axes of the operator's ankle joints; said rigid frame includes means for fixing the positions of both the operator's lower legs and ankle joints while performing the exercise movement, as by means of providing body-machine contact surfaces which apply constraining forces to the operator's body which balance the forces acting at the ball-of-the-foot-engaging surfaces which would tend to displace the operator's ankle joints and/or lower legs relative to the axis of rotation of said rigid rotating foot-engaging assembly; a rigid rotating weight arm which is journaled in said machine's frame on an axis which is both parallel with and separated by a specific distance from the axis of rotation of said rigid rotating foot-engaging assembly; said rigid rotating weight arm includes means for loading weights onto at a point offset from its axis of rotation; said rigid rotating foot-engaging assembly and said rigid rotating weight arm are mechanically linked to each other, at axes which are both parallel with and offset by specific distances from their respective axes of rotation, by a rigid connecting link which has a specific length between its centers of connection; said rigid rotating foot-engaging assembly, said rigid rotating weight arm, said link mechanically joining said rigid rotating foot-engaging assembly and said rigid rotating weight arm, and said frame of said calf exercising machine join together to form a four-bar linkage which, when acting in conjunction with the sinusoidally changing values of force applied by the machine's rotating weight arm as the weights swing through a circular path through the gravitational field, applies a predetermined variably resistive force at the ball-of-the-foot-engaging surfaces on said rigid rotating foot-engaging assembly, which varies as a function of the degrees of rotation of the operator's ankle joints and which is characteristic of the relationships in length and orientation of the four rigid members forming the four-bar linkage and the orientation of the rotating weight arm to the gravitational field throughout the range of the exercise movement; said specific distance between the axis of rotation of said rigid rotating foot-engaging assembly and the axis of rotation of said rigid rotating weight arm, said specific distance between the axis of rotation of said rigid rotating foot-engaging assembly and the axis of connection of said connecting link on said rigid rotating foot-engaging assembly, said specific distance between the axis of rotation of said rigid rotating weight arm and the axis of connection of said connecting link on said rigid rotating weight arm, and said specific distance between the centers of connection on said connecting link all have a definite non-changing relationship to each other, which relationship, along with their orientations to each other, is determined through kinematic analysis of the moving parts of the four-bar linkage/rotating weight arm force-varying mechanism and is dependent on said predetermined variably resistive force which said four-bar linkage/rotating weight arm force-varying mechanism is designed to put out throughout the exercise movement.