Advancing device

In an advancing device with a fluid power piston and cylinder arrangement comprising a stationarily mounted cylinder whose two ends are closed by cylinder end caps, a piston arranged for motion in the longitudinal direction of the cylinder, a piston rod connected with the piston and extending sealingly through one of the end caps, a load driving member mounted on a section of the piston rod located outside the cylinder and adapted to perform a linear advancing motion on operation of the piston and cylinder arrangement, and a guide for guiding motion of the load, the improvement that said arrangement comprises means defining at least two guide surfaces which are located (generally) opposite and plane-parallel to each other on an outer periphery of the cylinder, extend in a longitudinal direction of the cylinder continuously for a distance equal to the linear travel of the load driving member and face away from each other, said guide surface defining means being fixed longitudinally and rotationally in relation to the cylinder, and the load driving member having at least two bearer faces located facing and opposite each other and directly in contact with and parallel to the respective guide surfaces, the respective bearer surfaces for the entire travel of the load driving member slidably and directly engaging (an) respective adjacent ones of said guide surfaces permitting sliding movement of the load driving member in the longitudinal direction of the cylinder, the guide surfaces and the bearer surfaces are configured for precluding rotational movement of the load driving member around the cylinder during the entire travel of the load driving member, the entire travel of the load driving member, the load driving member having a workpiece carrying face located opposite to the bearer surfaces and facing away from the cylinder for carrying a workpiece along the entire travel of the load driving member.