Constant tension hydraulic brake

Claim 1

A BRAKE APPARATUS FOR APPLYING A CONSTANT BRAKING ACTION TO A ROTATING SHAFT COMPRISING A ROTATABLE DRIVEN SHAFT COUPLED TO THE ROTATING SHAFT BEING BRAKED, A CYLINDER, A HYDRAULIC CIRCUIT INCLUDING FLUID INLET AND OUTLET PASSAGES TO SAID CYLINDER, A PISTON MOVABLE IN SAID CYLINDER AND EFFECTIVE TO CAUSE MOVEMENT OF FLUID THROUGH SAID INLET AND OUTLET PASSAGES TO PUMP FLUID THROUGH SAID HYDRAULIC CIRCUIT, A CAM MEANS ROTATABLE WITH SAID DRIVEN SHAFT AND MOVABLE TO AN ECCENTRIC POSITION WITH RESPECT TO SAID DRIVEN SHAFT, SAID CAM MEANS BEING POSITIONED TO EFFECT MOVEMENT OF SAID PISTON IN ACCORDANCE WITH THE DEGREE OF ITS ECCENTRICITY, MOTOR MEANS CONNECTED TO SAID CAM MEANS AND ACTUATABLE TO VARY THE ECCENTRICITY OF SAID CAM MEANS, SENSING MEANS INTERPOSED IN SAID HYDRAULIC CIRCUIT FOR DETECTING CHANGES IN THE SPEED OF THE SHAFT BEING BRAKED AND FOR PROVIDING AN INDICATION OF DETECTED CHANGES IN SAID SPEED, AND FURTHER MEANS CONNECTED TO SAID SENSING MEANS FOR RELAYING THE INDICATION OF SAID SENSING MEANS TO SAID MOTOR MEANS TO ACTUATE SAID MOTOR MEANS TO VARY THE ECCENTRICITY OF SAID CAM MEANS AS A FUNCTION OF THE SPEED OF THE SHAFT BRAKED WHEREBY THE STROKE OF SAID PISTON IS VARIED TO MAINTAIN CONSTANT PUMPING VOLUME PER UNIT TIME IN SAID HYDRAULIC CIRCUIT.