Patent ID: 6186246
Filing Date: 2001-02-13
Classification: B25D

Abstract:
A method for adjusting drilling of a drilling machine, said drilling machine comprising a frame, a percussion piston supported in the frame for movement along a longitudinal axis, an absorber disposed at a front end of travel of a piston portion of the percussion piston so as to be contacted by the piston portion at the front end of travel of the piston portion, a shank supported in the frame in axial extension of the percussion piston so as to be impacted by said percussion piston in a working stroke thereof and at least two control pistons supported in the frame for longitudinal movement, said control pistons being disposed in cylinder spaces arranged around the longitudinal axis for moving the shank longitudinally to a selected percussion point at which the percussion piston impacts against the shank, said method comprising:applying pressure to each respective control piston to produce a respective stroke of each control piston,regulating the stroke of each respective control piston so that the control pistons have respective strokes, which are different from one another, to move the shank to corresponding different respective percussion points, andmoving the shank to said different selected percussion points by the respective control pistons by introducing pressure medium into said cylinder spaces at respective different controlled pressures so that the control pistons move the shank to respective percussion points in accordance with the strokes of said pistons whereby the shank is movable to a number of selected percussion points by the different control pistons.