Patent ID: 7174824

Claim:
A control valve for controlling a working cycle of a percussion device, the valve comprising: a frame including a space; at least two pressure medium channels connected to the space; a control element, which is arranged in the space in the frame, which is movable back and forth in a first control direction and in a second control direction and which is further arranged to open and close the pressure medium channels when the control element is moved back and forth according to its working cycle; at least a first working pressure space and at least a second working pressure space; a first control pressure channel for feeding pressure medium into a first working pressure space when the control element changes its direction; a second control pressure channel for feeding pressure medium into the second working pressure space when the control element changes its direction; at least a first working pressure surface, which is arranged to move the control element in the first control direction due to the influence of the pressure medium acting on the first working pressure space; and further comprising at least a second working pressure surface, which is arranged to move the control element in the second direction due to the influence of the pressure medium acting in the second working pressure space; and when the control element is moved in the first control direction from the middle position towards a first extreme position, the second working pressure space is arranged to close and form a closed pressure space, and correspondingly, when the control element is moved in the second control direction from the middle position towards a second extreme position, the first working pressure space is arranged to close and form a closed pressure space; the pressure medium in the closed pressure space is arranged to compress and convert kinetic energy of the control element into pressure energy; and the pressure energy in the closed pressure space is arranged to be re-converted into kinetic energy when the control element changes its direction.