Patent ID: 7975811

Claim:
A breaking mechanism comprising: a frame; a pair of levers, each of the levers having a brake pad at a first end thereof, a cam follower at second end thereof, and being mounted to the frame by a pivot disposed between said first and second ends; a cam disposed between the levers; a spring biasing the cam in a first direction; a clamp release actuator includes a hydraulic cylinder and piston, the clamp release actuator operable to displace the cam in a second direction, the second direction being opposite to the first direction; and a pair of variably sloped cam surfaces disposed on opposite sides of the cam, each of the variably sloped cam surfaces being in contact with the cam follower of a corresponding one of the levers, and each of the variably sloped cam surfaces having a slope which varies to counteract variations in a spring force of the spring as the cam is displaced, thereby maintaining a constant breaking force.