Abstract: A device for connecting to the body of a dentistry counter-angle the unit for transmitting the rotary movement of the major axis of the counter-angle to the oblique shaft contained in the head of the counter-angle. The transmission assembly is placed inside a socket (5), forming a case, the socket itself being fixed to the body of the counter-angle by means of a bayonet attachment, consisting of at least one pin (16), fixed to the inner wall of the body of the counter-angle, and of at least one L-shaped slot (12), formed on the socket. Application to the rapid assembling and dismantling of dentistry equipment.

Abstract: An angle-drive head of a dental handpiece with the housing thereof removable. A speed-increasing pinion is provided for meshing with a drive pinion of the angle-drive. A shaft connected to the pinion extends axially in the head and has a speed-increasing pinion for developing a greater speed. A speed-increasing device removably coupled to the head has a third speed-increasing pinion and a fourth pinion is coupled thereto. A tool-receiving jaw is provided in the device for coupling to the fourth speed-increasing pinion for being rotationally driven therefrom.

Abstract: This air-water mixer for the atomizer of a dental hand piece comprises a body formed with a circular chamber into which open an air supply conduit, a water supply conduit and an outlet conduit for the fluids. One wall of this chamber consists of the inner face of a selector ring mounted for free rotation in the chamber, the inner face of the ring comprising a flat sector adapted to close the inlet port of one and/or the other supply conduits in predetermined positions of the ring, and an inclined sector permitting the free passage of fluid between one and/or the other of the supply conduits and the outlet conduit in other predetermined positions of the ring, this mixer being particularly suited for a dental hand piece provided with an air-water atomizing conduit.