公开(公告)号：EP0227576A2

公开(公告)日：1987-07-01

申请号：EP86630190.6

申请日：1986-12-18

申请人： ENMARK CORPORATION

发明人： Buske, Robert James

IPC分类号： B25D9/12 ,  B25D9/20 ,  B25D9/26 ,  E02D7/10 ,  B28D1/26 ,  E01C23/12 ,  E21C27/28

CPC分类号： E02D7/10 ,  B25D9/12 ,  B25D9/20 ,  B25D9/26 ,  B25D2209/005 ,  B28D1/26

摘要： A hydraulic impact tool having a housing, a working tool, a ram, an energy storage device, and a valve slide. The tool also has a high pressure hydraulic fluid inlet port, an intermediate pressure hydraulic fluid inlet port, and one or two return lines. If there are two return lines, one of the return lines is for exhausting fluid from an upper annular chamber, and the other return line is for exhausting fluid from an intermediate annular chamber. The tool also has an optional delatch outlet, which can be opened and closed externally by the operator of the tool. The tool may also have a piston portion on the ram to restrict fluid flow between the ram and the valve slide as the ram is accelerated toward the working tool.