Slide valve, percussion device and method

1. Slide valve for a hydraulic percussion device, which slide valve comprises a transition surface that is arranged to alternately be subjected to a working pressure and a tank pressure to carry out a reciprocating movement when the percussion device is in use, wherein said slide valve is an annular member and comprises at least one channel which is open at one end of said slide valve, and at least one pin that is displaceable relative to said slide valve and that is at least partly arranged inside said at least one channel, whereby said at least one pin is arranged to be subjected to a working pressure that presses on one end surface of said at least one pin, the working pressure being introduced in said at least one channel between said end surface and a pressure surface opposite said end surface, whereby the other end surface of said at least one pin is pressed against a non-movable component of said hydraulic percussion device, which results in that said slide valve is pressed in the opposite direction to a direction in which said at least one pin is pressed.

2. Slide valve according to claim 1 , wherein said working pressure is achieved using a hydraulic fluid.

3. Slide valve according to claim 1 , wherein said at least one channel is in fluid communication with said hydraulic fluid via at least one conduit that is arranged to extend in said slide valve's radial direction when the slide valve is mounted in said hydraulic percussion device.

4. Slide valve according claim 1 , wherein said slide valve is arranged to be displaced between two end locations when the percussion device is in use, and said at least one pin is arranged to press the slide valve against a non-moveable component of said hydraulic percussion device, such as the machine housing, to provide an end seal between said slide valve and said non-moveable component at both end locations.

5. Slide valve according to claim 1 , wherein said working pressure is achieved with resilient material.

6. Slide valve according to claim 1 , comprising a cylindrical sleeve.

7. Slide valve according to claim 1 , having a plurality of different diameters.

8. Slide valve according to claim 1 , wherein a surface of said slide valve is arranged to be subjected to tank pressure when the percussion device is in use.

9. Slide valve according to claim 1 , wherein said at least one channel extends in said slide valve's axial direction when the slide valve is mounted in said hydraulic percussion device.

10. Slide valve according to claim 1 , wherein said at least one channel extends along at least 20% of the slide valve's length.

11. Slide valve according to claim 1 , including a plurality of channels and said plurality of channels is uniformly distributed around its periphery.

12. Slide valve according to claim 1 , wherein the outer diameter of said at least one pin corresponds to the inner diameter of said at least one channel.

13. Slide valve according to claim 1 , further comprising providing a seal between the non-movable component and the slide valve when the other end surface of said at least one pin is pressed against the non-movable component.

14. Method for making a slide valve of a percussion device to carry out a reciprocating movement when said percussion device is in use, which method comprises the step of alternately subjecting a transition surface of said slide valve to a working pressure and a tank pressure, wherein said slide valve is an annular member and is provided with at least one channel that is open at one end of said slide valve, and at least one pin that is displaceable relative to said slide valve and that is arranged at least partly inside said at least one channel, whereby said method comprises the step of subjecting said at least one pin to a working pressure that presses on one end surface of said at least one pin, said working pressure being introduced in said at least one channel between said end surface and a pressure surface opposite said end surface, whereby the other end surface of said at least one pin is pressed against a non-movable component of said hydraulic percussion device, which results in that said slide valve is pressed in the opposite direction to a direction in which said at least one pin is pressed.

15. Method according to claim 14 , wherein said working pressure is achieved using a hydraulic fluid.