Abstract: An air impact tool includes an inner tubular member that is connected to the barrel. The inner tubular member has an annular wall and a cavity. The annular wall has exhaust hole. An air flow channel communicating with the air flow control valve and the cavity is defined inside the annular wall. The air flow channel is formed with a first air inlet. A hammer is in the cavity. The hammer is in close contact with the annular wall. A cylindrical gap is defined between a middle section of the hammer and the annular wall. The hammer has an exhaust passageway communicating with the cavity and the cylindrical gap. When the compressed air is injected into the cavity from the first air inlet, the hammer is pushed back, and the compressed air is exhausted via the exhaust passageway, the cylindrical gap and the exhaust hole in sequence.

Abstract: A relief valve assembly limits the maximum torque of a gear motor of a hydraulically driven tool. The relief valve assembly dumps flow to a return channel to return hydraulic fluid to the supply when the relief valve assembly is activated. The relief valve assembly is placed in the channel of a directional valve spool, and varies its pressure setting depending upon spool position. This is useful to vary the pressure settings of a hydraulic motor in different directions.

Abstract: An air logic controller for increasing the efficiency of an air operated double diaphragm pump. The air logic controller may increase the efficiency of the pump by controlling the supply of compressed fluid to the pump. In one embodiment, the air logic controller may control the supply of compressed fluid to the pump by replacing the continuous, large volume supply of compressed fluid supplied to conventional air operated pumps during a single pumping stroke with a varied supply of compressed fluid. The varied supply of compressed fluid may comprise a supply of compressed fluid that alternates between a large volume supply and a small volume supply of compressed fluid. The air logic controller may vary the supply of compressed fluid to the pump based at least partially on the position of a main air valve spool and the setting on an adjustable pneumatic time delay relay.

Abstract: A fluid pressure piston-cylinder drive unit is reciprocated automatically by coupling the opposite ends of the cylinder through delivery conduits to a source of fluid pressure and exhaust through a switching valve in which a longitudinally reciprocative spool has a pair of passageways which reversibly couple one end of the cylinder to the source of fluid pressure and the other end of the cylinder to an exhaust conduit. The opposite ends of the switching valve contain shift pistons each of which engages an end of the spool through a coil spring. The shift pistons abut the opposite ends of an elongated rod which extends freely through a bore in the spool. Bypass conduits couple the opposite ends of the cylinder through the delivery conduits one to each end of the valve body such that fluid pressure in one delivery conduit from the source is coupled to one end of the valve body while exhaust fluid pressure from the other delivery conduit is coupled to the other end of the valve body.

Abstract: A linear unit (10) is provided with a cylinder (50) and a pressure-fluid actuated piston (52). The piston (52) runs in a borehole (51) of the cylinder (50). A slider (55) runs at the cylinder (50). A band (53) connects the piston (52) to the slider (55) and leads via deflection structure (54a, 54b) at the heads (11a, 11b) of the cylinder (50). Valves (15a, 15b) are screwed into the cylinder heads (11a, 11b) for feeding a pressure fluid to and discharging a pressure fluid from the borehole on two sides of the piston (52). The linear unit (10) provides an increased liberty of direction in a position-mounting of the linear cylinder heads (11a, 11b) and of the linear unit with valves (15a, 15b) as well as in the positioning of the connection terminal pieces. The linear unit (10) is flexible and is of modular construction and allows different types of device components to be flanged in the same position.

Abstract: A variable frequency control for a hydraulic percussion actuator includes a piston bore and a valve bore. A piston is axially disposed within the piston bore, while a valve is axially disposed within the valve bore. A first piston biasing member biases the piston in a first direction while a second piston biasing member, which overcomes the bias of the first piston biasing member to move the piston in a second direction. A first valve biasing pin biases the valve in a third direction while a second valve biasing pin overcomes the bias of the first valve biasing pin to move the valve in a fourth direction. A hydraulic valve actuator displaces the second valve biasing pin when the piston is extended in the second direction, and a piston actuator activates the second piston biasing pin when the valve is extended in the fourth direction. A valve response member controls the time required for the valve to be displaced in said fourth direction upon actuation of said valve actuating member.

Abstract: A reciprocating piston fluid powered motor having fluid inlet and outlet, wherein reciprocation is controlled by a reciprocable valve spool communicating with said fluid inlet and outlet and cooperating with a valve slide shiftable on said valve spool to control reciprocation of said valve spool. A needle valve assembly controls the exhaust rate proportionally to the operative speed of the motor.

Abstract: A fluid pressure operated impact mechanism of the type having a reciprocating working member guided for movement along an axis toward and away from a stop member, a pressure chamber between the working and stop members to receive a fluid pressure medium to exert forces separating the two members, and pressure sealing means for maintaining the pressure chamber sealed as the working member and stop member separate. The mechanism is characterized by a sealing arrangement which requires few precision parts yet is applicable to a variety of different devices. In the sealing arrangement, the pressure chamber is formed in the surface of at least one of the members, so that the two members meet along a separating line at the periphery of the pressure chamber. One of the members forms a support wall or flange extending in an axial direction along the separating line, and a flexible sealing means extends from the support wall of the one member to the other member, thereby effecting a seal therebetween.

Abstract: A portable and high-speed tool reciprocator for small tools, such as files, cutters, burnishing and polishing stones, leathers and the like, of a size easily held in one hand of an operator; fluid driven, preferably by a pneumatic fluid, the length of the reciprocatory stroke of which reciprocator may be adjusted, while in operative reciprocation, without the reorganization of its parts or the employment of extraneous gear, and the reciprocated tool may be selectively controlled to be either free or locked against rotation about its axis of reciprocation, while in operative reciprocation, without the reorganization of the reciprocator parts or the employment of extraneous gear, thus to enable the tool and its working face to move angularly relative to its axis of reciprocation and the holder, when free floating, or, when locked, to dispose the tool and its working face at some desired angle to tool reciprocation and the holder.

Abstract: A uniflow steam engine of the multi-cylinder type wherein the cylinders are rotatably mounted within a jacket having a sinusoidal cam track therein. Extending through slots, the ends of which are the exhaust ports in the cylinders and into the cam track are cam followers which are mounted on the pistons for reciprocable movement therewith. At the head end of the cylinders there are apertures which rotate with registered cutouts in superimposed valve rings that control the flow of steam from manifolds at the head ends of each of the cylinders into the cylinders as the cylinders rotate. By adjusting the relative position between the valve rings, the length of time of steam introduced on each cycle may be adjusted and by concomitantly rotating both valve rings, the initial time for introduction of steam may be adjusted to alter lead or reverse torque.