Patent ID: 7290622
Filing Date: 2007-11-06
Classification: B23B,B25D,E21B

Abstract:
1. An impact device for generating a stress pulse in a tool, the impact device comprising: a frame to which the tool is connectible; a transmission member disposed between the frame and the tool, the transmission member including: a stress element generating a force between the frame and the transmission member such that the force tends to push the transmission member towards the tool; a first hydraulic fluid space disposed on a tool-side relative to the transmission member and partially defined by the first pressure surface; and a hydraulic control system for leading pressurized hydraulic fluid into said first hydraulic fluid space and for enabling sudden flow of the hydraulic fluid out of said first hydraulic fluid space such that said force between the frame and the transmission member causes, either directly or indirectly via the transmission member and when the transmission member is in contact with the tool, a force compressing the tool in its longitudinal direction and, due to the effect thereof, a stress pulse in the tool in its axial direction, the hydraulic control system including: