Apparatus for making boreholes in the lateral walls of narrow underground mine workings

摘要

Difficulties are encountered in mining in making shot-firing boreholes from a narrow cross-heading into the lateral walls at right angles to the length of the cross-heading. The invention provides for this purpose a drilling unit with a flexible drilling shaft (5) formed by a steel spiral, which is brought up in the direction (7) of the cross-heading and is deviated within the unit substantially at right angles into the direction (10) of the borehole. The deviating station (3) provided for this purpose comprises, in a preferred embodiment, a turntable (11) fitted with pairs of rollers (12), which absorbs the substantial feed forces and reduces the wear on the flexible drilling shaft (5). The circulation fluid necessary for the drilling is conveyed through a pressure hose extending within the flexible shaft (5), which is connected pressure-tightly to the ends of the flexible shaft by means of special screw fittings. Special profiles, which are intended to prevent the turns from being rolled up, are provided for the steel spiral of the flexible shaft.