公开(公告)号：US20170370150A1

公开(公告)日：2017-12-28

申请号：US15629074

申请日：2017-06-21

Applicant: SANDVIK MINING AND CONSTRUCTION OY

Inventor： Esa RANTALA ,  Timo MUUTTONEN ,  Ari KOTALA ,  Pekka SAUKKO

IPC: E21B7/02 ,  E21B1/02

CPC classification number: E21B7/022 ,  E21B1/02 ,  E21B7/025

Abstract: A rock drill includes a frame, a percussion member, an axial shank, and an axial sleeve provided within the frame and including a first pressure surface provided in a first pressure space and a second pressure surface provided in a second pressure space. A first channel is provided in the axial sleeve for providing a connection between the first pressure space and the second pressure space in at least one position of the axial sleeve in the frame. A second pressure channel connected to the second pressure space is connectable to external pressure. A iu pressure accumulator is connected to the first pressure space and the flow of the pressure medium outwards from the first pressure space is throttled.