| 摘要 |
An apparatus for producing an upwardly directed drill hole with feed cylinders and a clamping cylinders contains a pressure medium system with a pump, a supply duct and a control valve. In order to attain a particularly favorable and simple design, a second pump is provided, for feeding a second supply duct, from which at least one branch duct containing a choke or the like leads to the drilling head or its tools. The control valve is provided between the first pump and the first supply duct for one set of sides of the clamping and feed cylinders. |
