Patent ID: 7051995

Claim:
A pressure-fluid driven device for generating a reciprocating movement, comprising: a first and a second axially relatively movable part, wherein a working chamber is intended to be alternatively pressurized so as to drive said parts in a movement relative to each other and depressurized, said first part is provided with a first channel for supply of driving fluid to said working chamber and said second part is provided with a second channel for discharge of fluid from said working chamber; and a valve arrangement having at least two valve elements which are being movable relative to said first and second parts is arranged to control the fluid flow in said first and second channel in dependence of the relative positions of said first and second parts, and thereby the pressurization of said working chamber, characterized in that said valve arrangement includes control means connected to at least one of said two valve elements so that said valve elements are axially separated from each other such that a fluid inlet into said working chamber of said first channel is separated from a fluid discharge from said working chamber into said second channel.