Abstract: A technique for pumping an output fluid, especially a particle-laden abrasive liquid. This technique utilizes an output pump and a drive pump which are interconnected through a common chamber containing a drive fluid, specifically water. The output pump includes an output piston within its own pumping chamber for pumping the output liquid by causing the output piston to move through a complete forward stroke. The drive pump includes a drive piston within its own chamber and means for causing the output piston to move the drive piston through its own complete forward stroke. This pressurizes the drive fluid within the common chamber in a way which causes the output piston to move in the forward direction of its stroke. The two pumps are configured such that the forward stroke of the drive piston defines a greater swept volume than the forward stroke of the output piston, thereby to ensure that the output piston will always move through its entire forward stroke before the drive piston.

Abstract: Deflection wedges are positioned in a generally horizontal drill hole in a predetermined orientation by means of a device which fits on the end of a drill string and is positioned in the hole. The deflection wedges positioned at the end of the device, and the device includes a unit which triggers at the predetermined angular orientation, to indicate that the wedge is correctly oriented. The orientation unit has a through passage for pressure fluid and a transverse passage intersecting the through passage. A blocking member is movable in the transverse passage and at a particular orientation moves along the transverse passage across the through passage. When crossing the through passage, the blocking member is entrained by the pressure fluid flow and moves to a position where it blocks the through passage, thus providing a signal to an operator that the unit is correctly positioned. The wedge is then secured in that position and the device withdrawn from the hole.