Method and valve apparatus for controlling a reciprocatable fluid actuated power machine

An apparatus for controlling the function of a reciprocatable power machine comprising:

• a cylinder having a reciprocatable piston located therein and dividing said cylinder into first and second pressure chambers;
• and
• a valve system which controls fluid pressures in said first and second pressure chambers, said valve system including
• a valve poppet having a plurality of channels in order (a) to provide a full power pressure fluid to said first pressure chamber to move said piston in an active power stroke from an end of a then active said first pressure chamber to an end of a then inactive said second pressure chamber and to provide an evacuation of the pressure fluid from the then inactive said second pressure chamber, and (b) to provide an evacuation of the pressure fluid from the then inactive said first pressure chamber when said piston moves in a return stroke,
• a building up means for building up a stopping counter pressure in the then inactive said second pressure chamber as said piston approaches the end of the then inactive said second pressure chamber to counter-act the full power pressure of the pressure fluid in the then active said first pressure chamber,
• a decreasing means for decreasing the stopping counter pressure in the then inactive said second pressure chamber to a positive final stopping counter pressure as said piston reaches the end of the then inactive said second pressure chamber so that said piston is softly stopped at the end of the then inactive said second pressure chamber against the final stopping counter pressure,
• a starting means for utilizing the final stopping counter pressure to start the return stroke of said piston from the end of a then active said second pressure chamber,
• a supply means for supplying the pressure fluid at a full power pressure to the then active said second pressure chamber after said starting means has started the return stroke of said piston to move said piston in an active return power stroke from an end of the then active said second pressure chamber to an end of a then inactive said first pressure chamber,
• a second starting means for providing a starting counter pressure in the then inactive said first pressure chamber as said piston starts to move from the end of the then active said second pressure chamber to counter-act the full power pressure of the pressure fluid in the then active said second pressure chamber, and
• a second decreasing means for decreasing of the starting counter pressure in the then inactive said first pressure chamber as said piston leaves the end of the then active said second pressure chamber so that said piston is softly started at the end of the then active said second pressure chamber;
• wherein said first-mentioned starting means further
• controls an opening of the then active said first pressure chamber to ambient to fully vent the full power pressure of the pressure fluid as said piston approaches the end of the then inactive said second pressure chamber, and
• closes the then inactive said first pressure chamber to ambient as the full power pressure fluid is supplied to the then active said second pressure chamber and said piston starts to move;
• and
• wherein said decreasing means vents the counter pressure in the then inactive said first pressure chamber to ambient.