Abstract: A clamping attachment to a device for driving elongated rod elements of low igidity into the ground comprises a housing (1) having a through tapered interior (2) and shoulders (7) on the outer surface. The interior (2) of the housing accommodates two spring-biased wedging elements (3) with slots (4). The slots (4) receive ends of arms (9) secured on the shoulders (7). Interposed between the spring (12) and wedging elements (3) is a washer plate (14). End faces (16, 17) of the wedging elements (3) and washer plate (14) are tapered. Contact surfaces (10, 11) of the slots (4,) and arms (9) are inclined to the longitudinal axis of the clamping attachment.

Abstract: The annular air-hammer apparatus for drilling holes comprises a shell hav fitted co-axially therein a chips-receiving sleeve, a hollow cylindrical case, and a ring-shaped hammer capable of reciprocating back and forth. The lower part of the shell accommodates a rock-cutting tool capable of moving axially with at least one blow-off passage formed by at least a single longitudinal groove made on the outer cylindrical surface of the rock-cutting tool. With the rock-cutting tool in its uppermost position, the blow-off passage communicates with an outlet space provided between the shell and the case.

Abstract: An annular air hammer apparatus for drilling wells has a cylindrical body which accommodates a stepped annular hammer mounted for reciprocations. A stepped air distribution tube is rigidly secured in the body and has inlet ports and exhaust ports, the tube cooperating with the hammer and defining therewith a work stroke chamber and defining a return stroke chamber with the body. A pipe for receiving drillings is stationary mounted in the air distribution tube and defines therewith a plenum. An annular member is provided between the pipe for receiving drillings and air distribution pipe, in the zone between the inlet and exhaust ports, to define an exhaust chamber between the pipe for receiving drillings and air distribution tube. The plenum and exhaust chamber permanently communicate with each other through a throttle means.

Abstract: An annular air-hammer apparatus for drilling holes incorporates a hollow cylindrical case with a stepped bore which has inlet and outlet ports. A rock-cutting tool with an axial opening is fitted to the case at the forward end thereof. A chips-receiving sleeve and a stepped ring-shaped hammer are located inside the case, whereby the hammer forms a working-stroke chamber with the case and an idle-stroke chamber with the case, the rock-cutting tool and the chips-receiving sleeve. The chips-receiving sleeve has a cylindrical protuberance at its upper end which interacts with the hammer when this is in its topmost position. A channel is provided in the idle-stroke chamber at that side thereof which faces the upper end face of the hammer.