Patent ID: 6960175

Claim:
An orthopedic knee brace mechanism incorporating upper and lower side braces adapted to support a portion of a user's leg above and below the user's knee with a knee joint housing there between adapted for pivotal movement, and leg bands adapted to secure the side braces against the user's leg, the knee joint housing comprising inner and outer housing members, the upper side brace being integral with the outer housing member so as to move therewith, and the lower side brace being integral with the inner housing member so as to move with it, a ratchet ring having internal teeth, the ratchet ring being mounted in the outer housing member so as to rotate when the upper side brace swivels, a plurality of cam action pawls mounted for operation around a central shaft in the inner housing member, the pawls being provided with teeth adapted to engage the internal ratchet ring teeth, and also with return springs to hold the pawl teeth in engagement with the ratchet ring teeth when they are engaged, means for coupling the inner and outer housing members to form a knee joint hinge in which the cam action pawls in the inner housing member engage the teeth inside the ratchet ring in the outer housing member, forming a ratchet within the housing, a control mechanism within the housing adapted to move the pawls into and out of a locking engagement with the ratchet ring teeth, the cam action return springs and the shape of the cam action pawl teeth being adapted so that the pawls allow rotation of the ratchet ring in a leg straightening direction while still supporting a load so that the leg can be extended for walking while at the same time being prevented by the cam action pawls from buckling in the knee bending direction, and an actuating rod adapted to drive the control mechanism to bring the cam action pawls into and out of a locking engagement with the ratchet ring teeth, advancing the cam action pawls when the user's foot engages a walking surface and disengaging the cam action pawls when the user's foot is not in the load bearing phase of walking.