摘要 |
A hydraulic percussive machine comprising a piston and cylinder with a dashpot at the front end to cushion overtravel of the piston. Heat is removed from the dashpot by admitting pressure fluid to the return stroke chamber through a front chamber and the dashpot. On the pressure stroke fluid from the return stroke chamber is admitted to the working stroke chamber in one case by causing all flow to take place along that route and in the other place by having two feeds to the working stroke chamber with a flow restrictor in the direct feed line. |