Patent ID: 7575432
Filing Date: 2009-08-18
Classification: A61B,A61C,F16C

Abstract:
1. A handpiece in combination with a surgical or dental tool, the tool having a tool end, a handpiece end and a shaft extending between the tool end and the handpiece end, wherein the shaft comprises a first shaft section and a region for positive torque transmission, which is located a distance from the handpiece end of the tool and which comprises a polygonal cross section, wherein the polygonal cross section is larger than a cross section of the first shaft section of the tool, the handpiece having a head with an insertion hole and a tool holder mounted in the head of the handpiece, wherein the handpiece end of the tool is adapted to be inserted in the head of the handpiece through an insertion hole into the tool holder, wherein the tool holder is rotationally supported by means of two axially separated bearings mounted in the head of the handpiece, with positive torque transmission to the tool, wherein the torque transmission occurs in the region of the bearing that is adjacent to the insertion hole, and wherein the torque transmission comprises a polygonal recess in the tool holder, wherein the tool holder is elongate and comprises a first section for accommodation of at least a part of the first shaft section of the tool, the first section of the tool holder having a first internal diameter, wherein the tool holder comprises a second section for accommodation of the region for positive torque transmission of the tool, the second section of the tool holder having a second internal diameter, and wherein the second internal diameter is larger than the first internal diameter.