Abstract: The present disclosure relates to prosthesis systems having trays and liners having an asymmetrical locking mechanism to bias the strength of the liner to resist loading forces and associated methods. The tray has a lateral groove disposed in an inner surface of a lateral circumferential portion of the tray and a medial groove disposed in an inner surface of a medial circumferential portion of the tray. The liner has an upper segment and a lower segment. The liner has a locking portion for lockingly engaging the tray that includes the lower segment. The locking portion has a lateral toe positioned generally diametrically opposite a plurality of resiliently deformable medial fingers defined therein. The liner and the tray are engageable in a lateral-to-medial direction so that the plurality of medial fingers can resiliently deform to engage the medial groove subsequent to engagement of the lateral toe within the lateral groove.

Abstract: Inserted in a hollow drive cylinder, a simple push-pull shaft is connected to a cup, open at one end and having a rigid rim and a transverse rod across the open end of the cup. Captured between the transverse rod and the closed end of the cup is a V-shaped spring. Two hardened steel pins on the outside ends of the V-shaped spring inserted through holes in a drive cylinder are inserted into and retracted out of engagement with openings on an interior surface of a concentrically encircling drive ring in response to expansions and compressions of the spring caused by the rim of the cup moved by the push-pull shaft. The push-pull shaft is moved by a push-pull knob outside the cylinder or cable activating knob remote therefrom. The rigid rim of the cup pushes on the sloping sides of the spring to compress the spring which then disengages the pins from the drive ring.

Abstract: A treadle drive system operates comfortably in a standing or seated position with two toe or heel end pivoting treadles. A flexible drive line (chain, cable, belt, etc.) from each treadle drives a pair of forward biased driving rings (having sprockets, pulleys, belt wheels, etc.) concentrically encircling and driving a hollow drive cylinder. Concentrically encircling the cylinder, a driven ring in turn drives a rotating device. A positive engagement clutch between the hollow cylindrical hub and the driven ring allows the driven ring to be engaged or disengaged from the drive cylinder. Opposing holes transversely through the hollow drive cylinder engage pins on outer ends of a V-shaped spring. The pins are normally engaged in mating openings on an interior surface of the driven ring. A push-pull shaft with a cup having a rigid rim pushes against the sloping sides of the spring to disengage the pins from the driven shaft only. Pulling the shaft releases the spring reengaging the pins in the driven shaft.

Abstract: A device that prevents wrapping of long strands of fibrous material around an exposed rotating shaft has a stationary flange fixed to the chassis or bearing housing for the shaft and a rotating flange fixed to the shaft. The flanges are positioned to pass one another during each revolution of the shaft. When the flanges are nearest to one another, a loop of vegetation forms tightly around the flanges. Continued rotation of the shaft then stretches and tears the loop apart. This loop forming and tearing is repeated for each revolution of the shaft to effectively prevent fibrous material from wrapping around the shaft.