Dental handpiece having improved bur release means

A dental handpiece for holding a workpiece that is used to treat the teeth of a patient, said dental handpiece including:

• a hollow collet having proximal and distal ends, the workpiece being removably received through said distal end so as to be surrounded by said collet and clamped at said proximal end thereof;
• a collet actuator disposed in spaced axial alignment with said collet, said collet actuator having workpiece release means sized so as to be received inwardly through the proximal end of said collet;
• a cylindrical spindle surrounding each of said axially aligned collet and collet actuator, said collet being fixedly attached to said spindle and said collet actuator being slidable reciprocally through said spindle relative to said collet;
• a push-button to which an axial pushing force is applied, said axial pushing force being transferred from said push button to said collet actuator to cause said collet actuator to slide through said spindle towards said collet so that said workpiece release means of said collet actuator is pushed into the proximal end of said collet to force said proximal end to move outwardly and into contact with said spindle, whereby to release the workpiece from said collet;
• and
• spring means aligned for engagement by said collet actuator, said spring means being compressed by said collet actuator when said collet actuator is pushed through said spindle and moved towards said collet in response to the axial pushing force applied to said push-button, and said spring means expanding to cause said collet actuator to slide through said spindle and away from said collet when said axial pushing force is terminated.