UNIVERSAL SCREW DRIVER Russian patent published in 2011 - IPC B25B15/00 

FIELD: machine building.

SUBSTANCE: screw driver has base and replaceable heads. The base corresponds to a plate with a case of a handle on top and an axle of a drum below. A rod with a spring on the end is positioned inside the case of the handle and passes through the drum; the rod can travel vertically. The rod is connected with a cap-gripper by means of a chain. A vertical slit with two nests is made in the case of the handle. Replaceable heads are installed in the drum. Each head consists of a rod, an edge and a guiding lug. On low surface of the base there is a circular groove, where in the guide lugs of the heads travel.

EFFECT: increased convenience of use.

6 cl, 2 dwg