Abstract: A handheld power tool 1 has a tool socket 2 to hold a tool along a working axis 11. A motor-driven, pneumatic striking mechanism 6 has an exciter 17 which is driven by a motor 5, a striker 14 that is coupled to the exciter 17 via a pneumatic chamber 19, and an intermediate striker 22 arranged on the working axis 11 in the striking direction 12 behind the striker 14. A ventilation opening 30 connects a cavity 29 situated between the striker 14 and the intermediate striker 22 to the environment. A valve 38 that closes the ventilation opening 30 is opened when actuated by the intermediate striker 22 when the intermediate striker 22 is moved into its working position counter to the striking direction 12.

Abstract: A valve assembly for controlling the flow of pressurized fluid supplied to an actuating cylinder having a piston driven by the pressurized fluid along a stroke path therewithin, the pressurized fluid being applied to alternative driving sides of the piston. The valve assembly comprises a first and a second valve pistons, which cooperate to block the supply of pressurized fluid to the current driving side of the piston when the piston reaches the end of its stroke path, thereby limiting the pressure of the pressurized fluid supplied to the driving side to a level reduced compared to a pressure level applied to drive said piston. If a leak occurs within the actuating cylinder at the end of the stroke path of the piston, it will be at the reduced pressurized fluid pressure.

Abstract: A hydraulic motor with rotating shaft coupled to a piston with alternating rectilinear displacement. The hydraulic motor comprises a casing enclosing a rotating shaft, a piston and an inverter comprising a first sleeve formed as one piece with the piston, a second sleeve, fixed in position, and a distributor mounted so as to rotate in the interior of the second sleeve and conduit and hole elements arranged between the second sleeve and the distributor and means for controlling the rotation of the distributor as a function of the displacement of the first sleeve so as to invert the direction of displacement of the piston.

Abstract: An arm structure intended for controlling the impulse valve (5) of the oscillating cylinder which performs a back and forth movement whereupon the oscillating cylinder comprises a cylinder body (14), a cylinder chamber (1) formed into the mentioned body, a piston (2) which can be moved in the cylinder chamber with the help of a pressure media, feeding channels (15, 16, 17) of the pressure media to the cylinder chamber (1) and control devices in order to direct the pressure media to the cylinder chamber to various sides of the piston and away from the cylinder chamber in order to achieve a back and forth movement for the piston and whereupon the impulse valves (5) belong to the control devices the operation of which at least one arm (10); (12), which explores mechanically the position of the piston arm (7) the movement of which arm is adjusted to open the pressure relieving channel of the impulse valve (5).

Abstract: A valve assembly for controlling the flow of pressurized fluid supplied to an actuating cylinder having a piston driven by the pressurized fluid along a stroke path therewithin, the pressurized fluid being applied to alternative driving sides of the piston. The valve assembly comprises a first and a second valve pistons, which cooperate to block the supply of pressurized fluid to the current driving side of the piston when the piston reaches the end of its stroke path, thereby limiting the pressure of the pressurized fluid supplied to the driving side to a level reduced compared to a pressure level applied to drive said piston. If a leak occurs within the actuating cylinder at the end of the stroke path of the piston, it will be at the reduced pressurized fluid pressure.

Abstract: The invention concerns an apparatus comprising a body (1) containing a cylinder wherein is mounted sliding an impact piston (1) of a tool, the motion of the piston being controlled by a distributor (15) which, arranged coaxial to the impact piston, is mounted inside a distribution box (3). The distribution box (3) comprises a part axially overlapping the piston (1) and arranged concentric thereto, and the distribution box (3) defines with the piston a control chamber (13) which, successively put under the high (9) and the low (12) pressure of the fluid, communicates through a passage (16) arranged in the distribution box (3) with a chamber controlling (14) the movement of the distributor (15), to generate alternately low pressure and high pressure.

Abstract: A reduced icing valve for an gas-driven motor and a reciprocating double diaphragm pump is provided having a shiftable valve for alternatively supplying a motive gas through first and second supply ports to opposed first and second power pistons in opposed motive gas chambers, respectively, and for effecting alternating exhaust of the chambers. The shiftable valve is provided with an insert that deflects, away from the shiftable valve, air entering from each of the bypass valves until the bypass valves are fully actuated by the exhaust gas from the motive gas chambers. The shiftable valve is further provided with bypass valves independent of and intermediate the shiftable valve and each of the first and second motive gas chambers for bypassing the shiftable valve by exhaust gas from the motive gas chambers. The bypass valves are further actuated in an opposing direction by a supply source of motive gas to the chambers.

Abstract: A reversing valve for a compressed air membrane pump in which an equilibrium state of the main piston in the neutral position, leading to stoppage of the pump, is prevented by disposing the main system piston and the pilot system piston immediately adjacent to one another.

Abstract: An air operated double diaphragm pump is provided with an air valve assembly which allows the valve cup to move in a rectangular pattern.

Abstract: Hydraulic drive mechanism for a machine element with rapid feed movement and under-load feed movement, comprising a double-acting hydrocylinder power drive and a pressure switching valve responding to the pressure at least in a larger operating chamber of the hydrocylinder when the pressure in the operating chamber exceeds a threshold value higher than 1/4 of the operating pressure of the pressure supply source, but lower than half the operating pressure thereof, switches to under-load feed operation and, when the pressure in the drive pressure or operating chamber falls below the threshold value, switches back to rapid feed operation. The pilot valve for the main control valve is equipped with two windings effective in opposite directions.

Abstract: A uniflow engine has a plurality of cylinders disposed symmetrically around a common crankshaft connected to pistons reciprocating in the cylinders. In response to the availability of a working fluid vapor at a predetermined condition, such as a high pressure or temperature, incoming vapor is supplied to those cylinders in which the respective pistons are in their working strokes to thereby initiate rotation of the crankshaft in a predetermined direction regardless of the position in which the crankshaft has stopped last. Once rotation is initiated and a predetermined mode change speed attained in a "start-up mode" by engine operation from start, vapor inlet valves are controlled to change engine operation over to a "running mode". In the "start-up mode" incoming vapor is admitted over a substantial portion of the piston working stroke, whereas in the "running mode" vapor inflow is terminated relatively early in the working stroke so that a vapor change does work in expanding against the piston.

Abstract: A uniflow engine has a plurality of cylinders disposed symmetrically around a common crankshaft connected to pistons reciprocating in the cylinders. In response to the availability of a working fluid vapor at a predetermined condition, such as a high pressure or temperature, incoming vapor is supplied to those cylinders in which the respective pistons are in their working strokes to thereby initiate rotation of the crankshaft in a predetermined direction regardless of the position in which the crankshaft had stopped last. Once rotation is initiated and a predetermined mode change speed attained in a "start-up mode" by engine operation from start, vapor inlet valves are controlled to change engine operation over to a "running mode". In the "start-up mode" incoming vapor is admitted over a substantial portion of the piston working stroke, whereas in the "running mode" vapor inflow is terminated relatively early in the working stroke so that a vapor change does work in expandiing against the piston.

Abstract: A hydraulic impact tool wherein hydraulic power is used to lift a ram against a bias to store energy and wherein the ram then is permitted to accelerate toward an impliment to which it imparts energy upon impact. A reciprocating cylindrical sleeve slidable about the ram is arranged to control the hydraulic fluid. The sleeve is initially carried in each direction by the ram and is shifted relative to the ram by hydraulic power.