Abstract: A knife sheath having front and back panels made of flexible material is lined with elongated flexible magnets affixed to the inner surface of the panels. The magnets grip the blade of the knife holding it in the sheath. Non-magnetic material separates the ends of the magnets at the sheath opening to facilitate entry of the knife blade into the sheath. A stiffener plate extending from a belt loop to the back panel prevents the connection between the belt loop and that panel from buckling when the knife is withdrawn. The stiffener plate may extend into the space between the sheath panels a substantial distance and have a flange on the edge thereof for preventing contact between the knife point and the edge of the sheath.

Abstract: Disclosed is a method and means for direct conversion of solar energy to mechanical energy through alternate warming and cooling of material consisting of highly aligned, high density polymer molecules. A strip of said material, when warmed by any means, contracts along its axis of alignment and such contraction can do mechanical work in a way mechanically similar to muscular contraction. A plurality of such strips mounted upon a rotor does work against gravity; the gravity field then returns the energy as torque.