Patent ID: 7645138
Filing Date: 2010-01-12
Classification: A61C

Abstract:
1. A dental tool assembly comprising: a housing body having a plurality of motorization means contained therein and a tool-holder head at one end thereof; a dental instrument or tool, said dental instrument being comprised of a shaft with an annular groove at one end thereof and having a flat surface in said annular groove parallel to a longitudinal axis of said shaft; a rotary spindle being comprised of a hollow spindle and a pinion, said hollow spindle having an open central bore traversing said hollow spindle longitudinally, the central bore receiving said dental instrument therein, said pinion being perpendicular to a central axis of said hollow spindle and meshing with said motorization means, said hollow spindle comprising: a locking spring, being comprised of a lower ring positioned around said hollow spindle and a plurality of elastic arms extending from one side of said lower ring, each arm being provided with a pin and having a rest position and a spaced-apart position, said pin engaging said annular groove of said dental instrument in said rest position, said pin being displaced away from said central axis of said hollow spindle in said spaced-apart position so as to release said dental instrument, each arm comprising: a cap-shaped push-button comprising a center conical pressure head on an underside thereof, the pressure head having an external slope engaging the arms of said locking spring, the pins being moved from said rest position to said spaced apart position when the push-button is depressed towards said dental instrument such that the pins release said annular groove of said dental instrument.