Motor driven rock drill with adjustable working dia. - rotates at right angle to and around borehole axis having adjustable stop for different diameters

摘要

The drill (1) has a swivelable tool holder (2) pivoting about an axis (3). There is an adjustable stop (4) for various borehole diameters with independent arrester. A low-spaced rotary linkage (5) moves in sideways (6,7) under a control (9). The drilling diameter is adjusted by a hydraulic unit (8), pref. via an over- and under-pressure of a hydraulic tool drive motor. The drill head may be shifted, moved, or swivelled for increasing or reducing the borehole dia. ADVANTAGE - Facilitates drilling boreholes of different size and/or for slightly changing borehole dia.