Abstract: A method for drilling boreholes utilizing a plurality of simultaneously operated boring tools. During a drilling operation the loading forces on the tools are measured and constantly compared with a predetermined limiting value representative of a limiting loading value and the variation of a limiting loading value with respect to time. If these limiting values are exceeded at least one working parameter of the tools is adjusted such as feed force, feed speed or track speed of the tools. Apparatus for carrying out the method is also disclosed.

Abstract: Device for actuating screw bolts, one end of which have spanner flats and the other end of which can be screwed into a receptor screw threading to form screw connections on flanges, lids, closures and the like, the device comprising a support member, the bottom end of which can be placed on a base, said support member having at least one opening for receiving at least one screw bolt end, and a spanner element which is retained by the support member or a part associated therewith and can be rotated by means of a motor drive, and can be brought into torque-transmitting connection with the spanner flats of a screw bolt.

Abstract: A drill string is mounted on a mast which is angularly adjustable relative to a frame. A support is connected to the frame so as to be angularly adjustable and has an open aperture for the drill string. The support is to be mounted on and secured upon a stationary member, such as a pipe, disposed at the operating location of the drilling apparatus.