Abstract: In the case of an incorrect polarity of connectors in hydraulic networks, a switching device is provided, and formed with a connector part, a valve body, a switching part displaced axially in the valve body within limits, a base part and a top part. Wherein cooperating annular chambers for the conducting of a working fluid are formed in the region of an inner surface of the valve body and an outer surface of the switching part. Annular surfaces (A2, A3, A5, A7) are acted upon with pressurized fluid on the switching part towards the top part and annular surfaces (A1, A4, A6) of the switching part are acted upon towards the base part have a following size relations when there is a permanent fluidic connection of the annular chambers: A2=A3>0.

Abstract: Control device of an impact mechanism operable by a pressure media having an element for reversing the axial pressurization of the percussion piston and the return of the medium. In order to achieve a controllability of impact mechanisms by which the energy and the frequency of the moved percussion piston can be adjusted, at least one channel switchable by the reversal as a return line for the medium from the percussion hammer has at least one switchable element for the flow control.

Abstract: Control device of an impact mechanism operable by a pressure media having an element for reversing the axial pressurization of the percussion piston and the return of the medium. In order to achieve a controllability of impact mechanisms by which the energy and the frequency of the moved percussion piston can be adjusted, at least one channel switchable by the reversal as a return line for the medium from the percussion hammer has at least one switchable element for the flow control.