| 摘要 |
<p>A dental handpiece (1) to releasably retain a workpiece (e.g. a dental bur) (50) that is used to treat the teeth of a patient. The workpiece (1) is clamped within a hollow collet (4) between a pair of flexible clamping fingers (38) having a spring-like memory. A collet actuator (9) is arranged in spaced axial alignment with the collet (4). Both the collet (4) and collet actuator (9) are surrounded by a cylindrical spindle (14). An axial pushing force applied to a push-button (8) of the handpiece (1) causes the collet actuator (9) to slide through the spindle (14) towards the collet (4). A pair of wedge-shaped tips (32) having an angle of preferably 22 degrees are carried by the collet actuator (9) into the hollow collet (4) to stress the pair of flexible clamping fingers (38) thereof. Accordingly, the clamping fingers (38) are rotated outwardly and away from one another through a stroke gap (42) so as to be moved into contact with the spindle (14), whereby the workpiece (50) is released for removal from the collet (4). <IMAGE></p> |
