Hilti Aktiengesellschaft

Werner Bongers

Werner Kleine

Axel Neukirchen

A rotary percussion blow assisted drill has an axially extending shank (1) with at least one main helically extending groove (4) in its axially extending outside surface (2) for conveying drilled material along the shank. A cutting plate (6) with hard metal cutting edges (7) is located in a cutting head end region (10) of the shank. The cutting edge (7) of the cutting plate (6) projects axially outwardly from a cutting head end face (3) of the shank (1) and the opposite ends of the cutting plate project radially outwardly from the outside surface of the shank. At least one pin-shaped guide element (11) is embedded into the outside surface (2) in the head end region (10) of the shank. The guide element (11) has a central axis disposed substantially perpendicularly to the axis of rotation (A) of the shank (1) and has a free end face (12) located radially outwardly from the outside surface of the shank by a dimension less than the dimension which the ends of the cutting plate are spaced radially outwardly from such outside surface.

Rotary percussion blow assisted drill

A percussive blow assisted rotary drill includes an axially extending shank (1) with a leading end face (3) and an axially extending outside surface (2) containing a helically extending drilled material removal groove (4, 5). At least one hard metal cutting plate (6) extends across a diameter of the shank and has a base part fixed in a continuous groove (9) in the leading end face (3) of the shank (1). The base part (10) is reinforced by an outwardly extending projection (12) in at least one of its side surfaces extending across the shank diameter. Preferably, the projections forms a part of a circle and are centered between the opposite ends of the cutting plate. The continuous groove (9) has a recess in at least one of its side surfaces shaped to coincide with the shape of the outward projection (12) on the cutting plate. Accordingly, the base part (10) is secured in a positively locked manner and preferably is centered in the leading end face of the shank.

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Munchen, Germany

Werner Bongers