Abstract: A surgical tool has a pneumatically driven rotor motor, a source of air under pressure to drive the motor, an output system for receiving rotation from the motor and transmitting it to a bur and a securing system for securing the bur to the output system. The securing system receives air pressure from the source of air and converts the pressure to a force acting on the bur to grip the bur. The motor has a shaft mounted for rotation in a housing, and the shaft is hollow so that some of the air directed into the motor goes through the shaft and into a chamber. A piston is mounted in the housing, and when air from the shaft is directed into the chamber, it moves the piston in the chamber. The piston is connected to a collet, so that introduction of air into the chamber moves the collet. The collet has an inclined surface, and there are grippers between the inclined surface and the bur.

Abstract: A dental turbine spindle assembly has a housing in which a pair of bearing supports are disposed concentric with an axis. A pair of bearings are disposed on the supports. A hollow spindle concentric with the axis is carried in a portion of the bearings and at one end projects through an opening in the housing. The projecting portion of the spindle is conical, is split and is threaded. A nut on the projecting portion is conical and is threaded to engage the spindle and has a circular portion partly disposed within a portion of a bearing. There is a wrench-receiving contour at the other end of the spindle accessible through an aperture in the housing.

Abstract: A dental hand-piece with an air turbine wherein a collet chuck holding a cutting tool spindle, a clamping member enough to clamp tapered chuck pawls of the collet chuck convergently from the outside, and further a moving element allowed to do the fine movement toward the outside owing to the centrifugal force acting thereon during the rotation of a rotary body are all together incorporated into the turbine rotary body supported by a shaft bearing inside a head casing, and which hand-piece is so designed in such manner that the fine movement of the moving element can provoke the sliding movement tending to clamp the chuck pawls between the collet chuck and the clamping member, is disclosed. In this hand-piece, the chuck pawls are automatically clamped at the time when the turbine rotary body starts to rotate, and the holding force of the collet chuck becomes greater to perform the reliable and steady holding of the cutting tool spindle the more high-speedily the rotary body rotates.