US 12,345,020 B2
Percussion device and method for controlling the same
Mika Oksman, Lahti (FI); Jyrki Nissinen, Lahti (FI); Juhani Laine, Lahti (FI); and Ossi Grohn, Lahti (FI)
Assigned to Sandvik Mining and Construction Oy, Tampere (FI)
Appl. No. 18/276,796
Filed by SANDVIK MINING AND CONSTRUCTION OY, Tampere (FI)
PCT Filed Feb. 8, 2022, PCT No. PCT/EP2022/052952
§ 371(c)(1), (2) Date Aug. 10, 2023,
PCT Pub. No. WO2022/171595, PCT Pub. Date Aug. 18, 2022.
Claims priority of application No. 21156648 (EP), filed on Feb. 11, 2021.
Prior Publication US 2024/0133158 A1, Apr. 25, 2024
Prior Publication US 2024/0229420 A9, Jul. 11, 2024
Int. Cl. E02F 9/22 (2006.01); E02F 3/96 (2006.01)
CPC E02F 9/2228 (2013.01) [E02F 3/966 (2013.01); E02F 9/2267 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A percussion device comprising:
a frame and a piston arranged inside the frame and configured to perform a working cycle including reciprocating longitudinal movement of the piston in an impact direction and a return direction due to pressure of hydraulic fluid fed to first and second working pressure spaces of the percussion device;
at least one sensing device arranged for detecting a position of the piston relative to the frame;
at least one feed valve arranged for controlling feeding and at least one discharge valve arranged for controlling discharging of the hydraulic fluid of at least one of the first and second pressure spaces; and
at least one control unit configured to control the feed valve and the discharge valve for executing the working cycle in response to sensing data received from the at least one sensing device and control parameters input to the control unit, wherein the feed and discharge valves are both controllable to a closed control state and to an open control state, the control unit being provided with at least one control cycle, wherein the feed and discharge valves are independently controllable, wherein the control cycle includes at least one overlap control feature, wherein the feed and discharge valves are simultaneously in the same control state, and wherein the overlap control feature is steplessly and independently controllable by control signals of the control unit, wherein the control unit is configured to determine a rebound ratio by comparing piston impact velocity in the impact direction to a piston rebound velocity in the return direction in response to detected position data received from the at least one sensing device, and wherein the control unit is configured to control the overlap control feature in response to the determined rebound ratio.