Patent ID: 7611315
Filing Date: 2009-11-03
Classification: A61B,A61C,Y10T

Abstract:
1. A motor element comprising: an elongated shank; a hollow drive shaft rotatably mounted in the elongated shank; a collet chuck for a tool arranged in a front end region of the hollow drive shaft; and a coupling that connects the collet chuck to a rod that extends rearwardly, wherein the rod is pretensioned rearwardly or frontwardly by a spring on the rod and can be displaced frontwardly or rearwardly against the spring by an actuating mechanism, the spring being rearwardly stayed on the rod and being frontwardly stayed behind an inner first shoulder of the drive shaft, wherein one or more spring arms are arranged at a front end region of the spring, the one or more spring arms are elastically pretensioned radially outwards and spring out behind the inner first shoulder when the rod and spring are plugged into a receiving hole of the drive shaft front end region and the one or more spring arms are seated in a position located behind the inner first shoulder, and the spring is rearwardly stayed on the rod against a bushing affixed to the rod, the spring pretensioning the rod toward the rear due to an axial staying of the spring arms on the inner first shoulder of the drive shaft.