A pump includes a liquid housing having a liquid chamber with a piston/diaphragm assembly arranged therein that responds to a suction stroke and draws liquid into the liquid chamber, and responds to a pressure stroke and provides liquid from the liquid chamber; and a gas housing having a slide valve assembly separating first and second gas chambers. The slide valve assembly responds to a suction-to-pressure-force at the suction stroke conclusion, changes from a suction-to-pressure stroke state, provides gas from the first to second gas chamber through the slide valve assembly, and provides the pressure stroke so liquid passes from the liquid chamber; and responds to a pressure-to-suction-force at the pressure stroke conclusion, changes from the pressure-to-suction stroke state, provides gas from the second chamber through the slide valve assembly, and provides the suction stroke so liquid is drawn into the liquid chamber.

One or more techniques and/or systems are disclosed for a flap valve in a diaphragm pump. The flap valve includes a body and a self-centering hinge portion. A front portion of the body includes a front surface having a raised portion and a recessed portion. The front surface is configured to form a seal with a surface of the pump when the body is in a closed position, the surface of the pump being at an inlet or an outlet of a pumping chamber. The body is configured to allow a downstream flow of a fluid when the flap valve is in an open position. The self-centering hinge portion is operably connected to the body. The self-centering hinge portion has a dynamically changing longitudinal axis. The body is configured to simultaneously translate and rotate about the dynamically changing longitudinal axis to form the seal.

A peristaltic pump with an oscillating drive 14 and a diverter valve 5, having a cylindrical pump housing 2 and the ports 4 and 12 are arranged in a end wall. The ports 4 and 12 are alternately used as outlet and inlet, controlled by the diverter valve 5 and in dependence on the pivot direction of the pump head 7. The roller or the sliding shoe 8 constantly flattens the pump hose and in this way, forms an annular space that is distinguished into a suction and compression chamber. Due to the constant contact of the roller or the sliding shoe 8, a sudden space enlargement is prevented according to the invention.

There is described a patch pump comprising a cartridge, a power source, a pump system, a drug delivery device and a control system configured to operate in particular the pump system and the drug delivery device. The pump system includes, on the one hand, a pump having a pump housing containing a pump piston and a valve piston and, on the other hand, a pump drive including a piston motor and a valve motor for driving the pump piston and the valve piston independently from each other through a first and a second transmission. The drug delivery device includes a transdermal delivery system having a needle actuation mechanism configured for transdermal insertion of a cannula.

A pump includes a liquid housing having a liquid chamber with a piston/diaphragm assembly arranged therein that responds to a suction stroke and draws liquid into the liquid chamber, and responds to a pressure stroke and provides liquid from the liquid chamber; and a gas housing having a slide valve assembly separating first and second gas chambers. The slide valve assembly responds to a suction-to-pressure-force at the suction stroke conclusion, changes from a suction-to-pressure stroke state, provides gas from the first to second gas chamber through the slide valve assembly, and provides the pressure stroke so liquid passes from the liquid chamber; and responds to a pressure-to-suction-force at the pressure stroke conclusion, changes from the pressure-to-suction stroke state, provides gas from the second chamber through the slide valve assembly, and provides the suction stroke so liquid is drawn into the liquid chamber.

There is described a patch pump comprising a cartridge, a power source, a pump system, a drug delivery device and a control system configured to operate in particular the pump system and the drug delivery device. The pump system comprises, on the one hand, a pump having a pump housing containing a pump piston and a valve piston and, on the other hand, a pump drive comprising a piston motor and a valve motor for driving the pump piston and the valve piston independently from each other through a first and a second transmission. The drug delivery device comprises a transdermal delivery system having a needle actuation mechanism configured for transdermal insertion of a cannula.

A pump adapted for use in desalination systems that has four cylinders, with a double acting piston in each cylinder. Each cylinder and piston thereby defines a feed chamber and a recovery chamber. The pistons are connected to a common drive. The connection to the common drive is such that the pistons reciprocate in a sequence equally spaced in time. Reciprocating valving for each piston is driven by the common drive to be 90 degrees out of phase with the respective piston. The valving connects the recovery chamber alternately to an inlet manifold for an intake stroke of the piston relative to the recovery chamber, and to an outlet manifold for a discharge stroke of the piston relative to the recovery chamber. There is a brief period of closure coinciding with top dead centre and bottom dead centre of the piston, during which the recovery chamber is blocked off from both the inlet and outlet manifolds. The reciprocating valving is midway between its top dead centre and bottom dead centre during the period of closure.

This invention disclosures a liquid storage tank upper cover assembly of a drawing or adding liquid machine and a drawing or adding liquid machine. The liquid storage tank upper cover assembly includes an upper cover, a switching valve foundation disposed at an upper end of the upper cover and a valve cartridge cooperated with the switching valve foundation. The upper cover and the switching valve foundation are a one-piece molded part. The switching valve foundation has a sliding hole, a lower part of the upper cover has a first through-hole and a second through-hole which are spaced apart, and the first through-hole and the second through-hole are both connected to the sliding hole. The switching valve foundation has a third through-hole connected with the sliding hole. The valve cartridge is glidingly provided in the sliding hole.

This invention disclosures a liquid storage tank upper cover assembly of a drawing or adding liquid machine and a drawing or adding liquid machine. The liquid storage tank upper cover assembly includes an upper cover, a switching valve foundation disposed at an upper end of the upper cover and a valve cartridge cooperated with the switching valve foundation. The upper cover and the switching valve foundation are a one-piece molded part. The switching valve foundation has a sliding hole, a lower part of the upper cover has a first through-hole and a second through-hole which are spaced apart, and the first through-hole and the second through-hole are both connected to the sliding hole. The switching valve foundation has a third through-hole connected with the sliding hole. The valve cartridge is glidingly provided in the sliding hole.

A pump adapted for use in desalination systems that has four cylinders, with a double acting piston in each cylinder. Each cylinder and piston thereby defines a feed chamber and a recovery chamber. The pistons are connected to a common drive. The connection to the common drive is such that the pistons reciprocate in a sequence equally spaced in time. Reciprocating valving for each piston is driven by the common drive to be 90 degrees out of phase with the respective piston.

The valving connects the recovery chamber alternately to an inlet manifold for an intake stroke of the piston relative to the recovery chamber, and to an outlet manifold for a discharge stroke of the piston relative to the recovery chamber. There is a brief period of closure coinciding with top dead centre and bottom dead centre of the piston, during which the recovery chamber is blocked off from both the inlet and outlet manifolds. The reciprocating valving is midway between its top dead centre and bottom dead centre during the period of closure.