Abstract: A straight dental handpiece has a tubular housing for a motor driven collet mechanism rotatably supported at one end of the housing. The burr receiving collet mechanism is actuated by a pair of diammetrically opposed cams supported for rotational movement about an axis extended transversely of the housing. In response to rotation of the cams, a cam follower on the collet mechanism is axially moved to actuate the collet mechanism to a burr receiving position. The cams are rotated by an external lever on the housing that is pivotally movable from a longitudinally extended operating position in nested relation with the housing, wherein the burr is gripped in the collet mechanism, to a burr releasing position projected generally radially of the housing.

Abstract: A dental syringe is connectible to sources of air and water under pressure for selectively providing a solid stream of water, a jet of air or a spray of water and air. The maximum rate flow of air and/or water to be used is independently metered in the handle portion of the syringe to limit the flow as required by the dental work being performed. Valve assemblies in the valve body porton of the syringe for independently controlling the air and water flow have respective actuator means each of which is interconnected with the valve assembly therefor to pull back into the water passage system downstream of the valve assembly any wafter that may be adjacent to the orifice of the syringe when the water flow is interrupted.

Abstract: A straight dental handpiece comprising a pair of telescoping housing barrels which can normally swivel relative to each other, one containing a chuck and the other containing a vane type air motor. A change speed transmission is entrained between the motor and the chuck, such transmission being adjustable to change speeds by relative endwise movement of the barrels. Opening and closing of the chuck is accomplished by relative rotation of the barrels while holding down a stop button. A reversing valve, also on the handpiece, is movable into either of two positions relative to one of the barrels to supply air under pressure to either of two passages to drive the motor in one direction or the other.

Abstract: A straight dental handpiece comprising a pair of telescoping housing barrels which can swivel relative each other, one containing a chuck and the other containing a vane type air motor. A change speed transmission is entrained between the motor and the chuck, such transmission being adjustable to change speeds by relative endwise movement of the barrels. Opening and closing of the chuck is accomplished by relative rotation thereof a limited amount. A reversing valve, also on the handpiece, is movable into either of two positions to apply air under pressure to either of two passages to drive the motor in one direction or the other.