Antifriction mechanical joint for an orthopedic knee brace

Claim 1

In an orthopedic knee brace having an upper arm to be secured to a wearer's body above the knee, a lower arm to be secured to the wearer's body below the knee, and a mechanical joint between the upper arm and the lower arm to permit flexing of the knee, an improved antifriction mechanical joint comprising: a first bearing plate on an end of the lower arm and a second bearing plate on an end of the upper arm; a link having a first bearing surface to mate with the first bearing plate, and adjacent thereto a second bearing surface to mate with the second bearing plate, thus providing a first bearing at the first bearing plate and a second bearing at the second bearing plate; a first cavity having curved internal surfaces in the first bearing plate and a second cavity having curved internal surfaces in the second bearing plate; a first cam having curved external peripheral surfaces within the first cavity and a second cam within the second cavity, the cams having curved external peripheral surfaces attached to the link; at least two cylindrical rollers in the first cavity and in the second cavity, the rollers fitting between the internal surfaces of the cavities and the external peripheral surfaces of the cams, the shape of the cams and the shape of the cavities permitting multiple axis pivotal movement of the mechanical joint substantially corresponding to the knee movement of the wearer between a flexed position and an extended position of the knee, and cover means over the first bearing plate and the second bearing plate attached to the link to retain the rollers within the cavities.