Dental handpiece with fluid delivery control

Claim 1

A dental handpiece provided with means for controlling the delivery of fluids to the tool, which comprises an air supply conduit and a water supply conduit from the motor and an outlet conduit directed to the head of the handpiece, wherein said water and air supply conduits open each into a circular groove, respectively, formed in the inner periphery of a socket which is an easy fit to the retaining end of the motor, said socket having two radial ports formed through its wall, said ports being off-set both axially and angularly, and opening on the one hand into said grooves and on the other hand into an annular chamber formed between said socket and the body of the handpiece, said outlet conduit being connected to said chamber, a rotary ring adapted to be easily rotated from outside being mounted in said chamber and provided in its peripheral wall with a pair of seals off-set axially to the same extent as said ports formed in the socket, said seals being so shaped that in the first limit position of said ring the first seal closes the water supply port while the second seal uncovers the air supply port, in a second limit position said first seal uncovers said water supply port while said other seal closes said air supply port, an intermediate position of said ring causing said seals to free both air and water supply ports.