Abstract: The adjusting device for a rotary tool contains a flexible spring, with radially adjustable cutting plates. The holder can be deflected relative to a support by a setscrew, with a pressure zone on a threadless circumferential part jointly with a complementary zone on the holder forming a wedge surface pair. During its adjustment, the cutting plate experiences a radial displacement. The annular scale has graduation marks and at least one orientation mark A conical section of the adjusting screw (8) has an angle (?/2) of 4.5 to 24°, the pitch of the setscrew (8) is 0.1 to 0.3 mm and the adjustment range is 0.1 to 5 mm.

Abstract: The invention relates to a tool head, especially a fine drill head, comprising a machine shank and a tool shank having a joint center axis, wherein the tool shank has a rigid core and a head with a tool, supported by a parallel spring arrangement and is able to be elastically displaced in relation thereto, said head having several limbs which emanate therefrom and form the parallel spring arrangement, whereby at least one of said limbs is fixed to the core or machine shank. The inventive tool head also comprises a device for radial displacement of the head in relation to the core, comprising a positioning device which has a conical part and is guided inside the core. The conical part bears against a contact part of the parallel spring arrangement under pressure when in use. The core is configured with the parallel spring arrangement in a single piece.

Abstract: A drilling tool is proposed comprising a shaft which has both a chuck shaft suitable for fitting in machine tools and a drill-holding shaft, known per se, with chuck grooves and (optionally) coolant ducts. A replaceable drill bit (1) is fitted in a positive fit and detachably on the shaft. The drill bit can consist of a homogenous material and has cutting edges (2) inclined radially outwards and backwards; these cutting edges can be formed in one piece from the drill bit material or are composed of blades mounted in the central region and made from the drill bit material and complementary blades orignating from a cutter plate screwed onto the drill bit. The invention proposes that the cutting edges (2) should be aligned symmetrically about the drill bit axis and the cutting edges should be in cutting engagement over the entire radius of the bore to be drilled.