Releasable Conical Roller Clutch for Knee Brace

A compact conical roller clutch can be either (1) engaged to obtain both positive locking against rotation in one sense and freewheeling in the opposite sense or (2) disengaged to obtain free rotation in both senses. This clutch was devised to enhance the functionality and increase the durability of the orthotic knee brace described in "Knee Brace Would Lock and Unlock Automatically" (MFS-28991), NASA Tech Briefs, Vol. 19, No. 12 (December 1995), page 28. In the knee brace, the clutch can be actuated selectively to prevent undesired flexion when weight is applied or to allow both flexion and extension when weight is not applied or when it is desired to exercise leg muscles.