Abstract: A heating system has an air intake and an air outlet. A heater is in communication with the air intake and the air outlet. The heater has a first surface and a second surface. The first surface is movable relative to the second surface to generate frictional heat between the first surface and the second surface.

Abstract: A piston chamber assembly has a chamber and a piston slideably received in the chamber. The piston has a first side and a second side. A first inlet communicates air into the chamber on the first side while a second inlet communicates air into the chamber on the second side. An actuator is moveable between a first position and a second position. The actuator selectively opens and closes the first inlet and the second inlet. In the first position, the actuator closes the second inlet and opens a first inlet while in the second position the actuator opens the second inlet and closes the first inlet. The actuator is coupled to the piston, which drives the actuator between the first position and the second position.

Abstract: A surgical blade assembly comprises a scalpel blade and handle. A guard is attached to the assembly and is pivotally moveable between a sheathed and an unsheathed position. A spring resiliently biases the guard to the sheathed position. A hinge may attach the guard to the assembly and allow pivoting of the guard relative to the blade.

Abstract: A structure is disclosed for holding medical sharp instruments within covers. Contrary to the prior art, the medical sharp instruments are held within the cover, both during use and non-use positions. Most preferably, some locking structure is provided which locks the medical sharp instrument within the cover at both the use and non-use positions.

Abstract: Several locks for locking a seat back relative to a seat bottom are disclosed. The locks include members which are moveable into notches in a rod to lock the rod within a block. In one embodiment, an axially moveable pin forces a ball into a notch in the rod to lock the rod at a desired location. In a second embodiment, an axially moveable tooth is selectively moved into or out of a notch in the rod. In a third embodiment, a rotating cam forces a lock seat onto the rod to lock the rod at a desired location. Finally, a power driven embodiment is also disclosed.