Patent ID: 7758479

Claim:
An exercise machine comprising: a frame including a rigid upright member; a pair of upper pivot and a pair of lower pivots mounted on said upright member; the distances between respective ones of said upper pivots and said lower pivots defining first legs of left and right force triangles; a pair of lever arms, each having a proximal end coupled to a respective one of said upper pivots and a distal end adapted for receiving user forces; said lever arms each including a plurality of adjustment points; a pair of slidable couplings, each movable over a respective one of said lever arms, for selective engagement with any of said respective pluralities of adjustment points; a pair of compression springs, each connected between a respective one of said lower pivots and a respective one of said slidable couplings; the distances between said upper pivots and the connections between said compression springs and said slidable couplings defining respective second legs of said force triangles; said compression springs each having a free length defining respective third legs of said force triangles; and each of said compression springs readily supporting its corresponding one of said lever arms when the corresponding one of said slidable couplings is in any of said corresponding adjustment points, in the absence of said user forces.