Abstract: Replacing valves in prior percussive devices, the distributor is a simple tube, which can be of plastic construction, for admitting operative compressed air to drive and return chambers at opposite ends of the centrally-bored hammer piston. The tube-distributor effects a fine, substantially sealing, relatively slidable clearance with the hammer piston bore. The housing is a simple, uniform bore diameter cylinder in which the hammer piston reciprocates; tight-concentricity tolerance machining of the confronting inside and outside diameters of the cylindrical housing, distributor and hammer piston, respectively, is unnecesssary.

Abstract: The novel system discloses both a batch operation and a continuous operation for supplying pressured liquid and a pressured slurry to an abrasive-jet cutting nozzle. In the batch operation, a single vessel for receiving and pressuring slurry is provided and this vessel goes off line, to be recharged with slurry, when it has disgorged its contents to the nozzle. In the continuous operation, a pair of such vessels are provided, and one supplies the nozzle with slurry while the other, having been emptied, is recharged with slurry; valves switch therebetween, to put a re-charged vessel on line, and an emptied one re-charging, to maintain a continuous slurry input for the nozzle.

Abstract: The apparatus confines abrasive slurry in one chamber of a dual-chamber reservoir having a piston sealing between the two chambers. Pump-pressured water is conducted to the other chamber (a) to displace the piston and, consequently, (b) to pressure the slurry. A fluid line conveys the pressured slurry to a central, orifice-terminated, channel formed in the axial center of a nozzle, and another fluid line conveys pump-pressured water to an annular conduit, formed in said nozzle, which circumscribes the central channel. The annular conduit also terminates in an orifice. Both orifices are axially aligned, the latter one being of greater diameter than the former. Upon emerging from the aforesaid conduit and channel, the water and slurry accelerate together in a convergent chamber of the nozzle to discharge via the larger-diameter, final exit orifice.

Abstract: A reciprocating machine comprising a cylinder with a drive chamber and a return chamber; a piston arranged to move to and fro in the cylinder with a first piston area exposed to the drive chamber and being smaller than a second piston area exposed to the return chamber; a permanently open inlet for fluid to the drive chamber; a restricted outlet for fluid from the return chamber; a bore extending through the piston from a port in its first area to its second area; a first valve with a head adapted to seat on the port and a stem guided in the end wall of the drive chamber; and means for limiting the extent of travel of the first valve with the piston so that the first valve can travel with the piston only part of the way from the drive chamber toward the return chamber.

Abstract: This invention pertains to a fluid actuator having piston chambers, a piston maintained within said chambers, a valve means for reciprocating the piston and a pressure control means for varying the force to the valve means wherein the reciprocating frequency of the piston is modulated.

Abstract: The nozzle is used with a system for removing contaminants from a liquid including a source of dissolved air in water under pressure and includes a first member with a hole through which the dissolved air and water flows. A floating member is also provided. The shapes of the first member and the floating member are such that the hydraulic forces resulting from the flow of water outwardly between the two members causes the floating member to float a predetermined distance from the first member. The shortest distance separating the first member and the floating member is such that most bubbles exiting from between the two members have a diameter less than 100 microns.

Abstract: A hydraulically operated reciprocating piston and a differential force operated valve are both in continuous fluid contact with a pressurized cushion chamber as well as the piston chamber pressure. The valve position is a function of the cushion chamber pressure. The cushion chamber pressure is a function of the axial position of the piston. The values of these functions are such that the piston is reciprocated when the machine is operated. The valve is a sleeve coaxial with the piston.

Abstract: A hydraulically operated reciprocating piston and a differential force operated valve are both in continuous fluid contact with a pressurized cushion chamber as well as the piston chamber pressure. The valve position is a function of the cushion chamber pressure. The cushion chamber pressure is a function of the axial position of the piston. The values of these functions are such that the piston is reciprocated when the machine is operated. The valve may, for example, be a sleeve coaxial with the piston or a valve transversely spaced from the piston.