Patent ID: 6155826
Filing Date: 2000-12-05
Classification: A61C

Abstract:
A grip chuck spindle assembly for dental handpieces comprising:a spindle of generally open ended hollow cylindrical shape with outside diameter to be mounted in a dental handpiece and having at least three different diameter bores therein;a plunger end of the spindle having the smallest diameter bore therein for retention of a plunger slidably inserted in the spindle wherein the plunger seats against a step such that a button end protrudes from the spindle;a spindle bur end having the largest diameter bore therein and thereby creating in the spindle an intermediate diameter bore therein for retention of a clamping bushing of generally open ended cylindrical hollow shape having a bore formed therein, the clamping bushing slidably inserted in the spindle wherein the clamping bushing having an annular seat which seats against a bushing step and the spindle bur end is pressed against the clamping bushing bur end;a clamping end of the clamping bushing having a plurality of clamping fingers formed by a plurality of slots each with an oval aperture formed therein and a portion of the clamping end having a clamping bore therein which is of smaller diameter than the clamping bushing bore; andthe plunger having a wedge end which engages the slots such that when a force is exerted to press the plunger along the longitudinal axis the wedge end spreads the clamping fingers apart for disengaging a dental tool retained therein.