Patent ID: 8087329

Claim:
Screwdriver for bone screws, comprising: a handle, a shaft rotationally fixedly held on the handle, a free end of the shaft having a non-circular cross section and being insertable in a positively locked manner in a non-circular receiving opening in a head of a bone screw, at least one expander element mounted so as to be displaceable in a longitudinal direction in the shaft and so as to slide, when displaced in the longitudinal direction, along a slide surface in an area of the free end of the shaft in such a way that the at least one expander element projects laterally over a contour of the shaft, and an elastic spring element for pretensioning the at least one expander element in a direction towards the free end of the shaft, the at least one expander element being retractable against action of the spring element in the shaft until the at least one expander element no longer projects laterally over the contour of the shaft, wherein: the at least one expander element is connected via a transmission member to an advancing device located on the handle, the elastic spring element is part of the advancing device; the advancing device comprises a sleeve which is connected to the at least one expander element and is displaceable on the shaft; and a swivel element which is mounted on the shaft for swivel movement at one end and is able to swivel about a bearing point against an outer surface of the shaft is provided for displacing the sleeve, and the swivel element comprises a driver which displaces the sleeve against the action of the spring element when the swivel element is swiveled against the shaft.