Abstract: The dosing arrangement comprises two first pumps for a liquid medium B whose pistons are mutually connected by a piston rod, and two other pumps and for a liquid medium A which are positioned outside in continuation of and coupled to the pumps for liquid B. The two pumps for liquid B are firmly fixed to a central body which is hollow and filled up with liquid B, and in which are mounted two mutually connected suction valves which are activated by the pistons by means of a push rod and switched over momentarily from one extreme position to another by a spring mechanism and two exhaust valves whose movements are derived from the valves. Furthermore, the central body incorporates an opening/closing arrangement, which can admit a variable volume of liquid B through a valve into the cylinder for liquid A, which is under a suction pressure, whereby the proportion of mix can be regulated.

Abstract: A reciprocating device comprising a housing having a chamber and a reciprocable member reciprocable in the chamber. First and second pressure valves are connectible to a source of fluid under pressure to drive the reciprocable member and first and second passages lead from the first and second pressure valves to the chamber on opposite sides of the reciprocable member, respectively. First and second exhaust valves are coupled, respectively, to the first and second passages at locations intermediate the associated pressure valve and the chamber and communicating with the first and second vents, respectively. Actuators are drivable by the piston for switching the valves between first and second positions, and the fluid under pressure retains the valves in whichever of the positions they are placed.

Abstract: There is described a fluid pressure booster including a pair of cylinders connected to the opposite sides of a central partition wall of a casing with an inlet port, an outlet port and air exhaust ports, a pair of pistons reciprocable in the cylinders and defining a boosting chamber and a drive chamber in each cylinder, and a switch valve adapted to supply a line air pressure alternately to the drive chambers of the two cylinders, thereby reciprocating the pistons to intensify the fluid pressure in the boosting chambers. The switch valve of the booster is provided with a spool stall preventive means which is arranged to suppress the pressing force on the valve body of the switch valve with the fluid pressure or biasing action of a spring until the valve body reaches the neutral position thereof and to encourage the pressing action on the valve body with a biasing force after reaching the neutral position to prevent stalls of the valve body at that position.

Abstract: There is described a fluid pressure booster including a pair of cylinders connected to the opposite sides of a central partition wall of a casing with an inlet port, an outlet port and air exhaust ports, a pair of pistons reciprocable in the cylinders and defining a boosting chamber and a drive chamber in each cylinder, and a switch valve adapted to supply a line air pressure alternately to the drive chambers of the two cylinders, thereby reciprocating the pistons to intensify the fluid pressure in the boosting chambers. The switch valve of the booster is provided with a spool stall preventive means which is arranged to suppress the pressing force on the valve body of the switch valve with the fluid pressure or biasing action of a spring until the valve body reaches the neutral position thereof and to encourage the pressing action on the valve body with a biasing force after reaching the neutral position to prevent stalls of the valve body at that position.

Abstract: This invention relates to an improved air driven pump for pumping products such as beverage syrups. Two opposed pistons are mounted on a common piston shaft for reciprocal movement within a housing. Cavities corresponding to the pistons are alternately vented and pressurized to intake the product into a pair of cylinders and to drive the pistons to pump the product. A spool valve stem extends into the cavity being vented so that the piston performing an intake stroke moves the valve stem into the other cavity. A pair of axial passages and corresponding side openings in the valve stem provide fluid flow paths for venting and pressurizing the cavities. A valve body biased toward the cavity being vented includes a vent passage for alternately venting the cavities through the side inlets. While one cavity vents, pressurized fluid flows into the other cavity through the corresponding side inlet and axial passage.

Abstract: A pneumatic-hydraulic pumping device including a jacket member, a cap member mounted at one end of the jacket member and an hydraulic head member mounted at the opposite end of the jacket member. An air head member is mounted in the jacket member intermediate the cap and hydraulic head members to form an air piston chamber between the cap member and the air head member and an hydraulic fluid reservoir space in the jacket between the hydraulic head member and the air head member. An air piston means including a piston head and a piston rod fastened thereto is mounted for reciprocal movement in power stroke and exhaust directions inside the air piston chamber with the piston rod being slidably mounted in the air head member. An air piston return means is mounted in the jacket for moving the piston means in the exhaust stroke direction. The air head member is connected to a source of air pressure by a conduit means.