Patent ID: 7857109

Claim:
A brake actuating cam disposable intermediate a pair of following surfaces on first ends of a pair of arms, the arms being rotatable about parallel axes and having a pair of opposing brake surfaces at second ends, the cam comprising: a body having first and second opposite cam surfaces adapted to engage said following surfaces and a bore intermediate said cam surfaces; a piston receivable in said bore, said piston being releasably coupled to said bore; and an adjuster for controllably varying the position of said piston in said bore, wherein said piston may be engaged by an actuator via said brake actuating force so as to wedge said cam between the following surfaces of the arms so as to rotate the first and second arms about their respective axes thereby frictionally engaging an object between the braking surfaces, wherein said bore includes an end surface located between the cam surfaces, said piston being located between the end surface and the actuator, said bore adapted to receive a pressurized fluid between said piston and said end surface so as to displace said piston away from said end surface.