Patent ID: 8702339

Claim:
A clamp for clamping a first member to a second member, the clamp comprising: a lever that is rotatably coupled to the first member, the lever comprising a handle and a cam that rotate together about a rotational axis; and a plunger; wherein rotation of the lever about the axis in a first direction cams the plunger towards the second member to couple the first and second members together and wherein rotation of the lever about the axis in a second, opposite direction cams the plunger away from the second member to uncouple the first and second members from each other; wherein the cam comprises a first cam surface camming the plunger towards the second member when the lever is rotated in the first direction and a second cam surface camming the plunger away from the second member when the lever is rotated in the second direction; wherein the first cam surface comprises an outer curved surface that is radially eccentric with respect to the rotational axis; wherein the outer curved surface is shaped so that an amount of torque necessary to rotate the lever about the axis is greatest at an over-center rotational position, such that the lever is retained in position after it is rotated past the over-center rotational position in the first direction and such that the lever is retained in position after it is oppositely rotated past the over-center rotational position in the second direction; wherein the plunger comprises an inner cam surface that is cammingly engaged by the eccentric outer curved surface of the first cam surface when the lever is rotated in the first direction to thereby move the plunger towards the second member; wherein the second cam surface comprises outer surfaces on opposite sides of the inner cam surface, the outer surfaces being radially eccentric with respect to the rotational axis; wherein the plunger further comprises opposing retaining rings that are cammingly engaged by the outer surfaces of the second cam surface when the lever is rotated in the second direction to thereby move the plunger away from the second member; and wherein the retaining rings are spaced apart from each other so that the lever can rotate between the retaining about the rotational axis and past the over-center rotational position in the first and second directions.