Abstract: In general, a piston-type pump includes a wash flow path that allows a wash liquid such as water to pass through to provide washing and cleaning as the pump operates. The pump may be used in precision liquid dispensing systems and particularly with liquid solutions that have a tendency to precipitate solid particulate. By washing a portion of the pump piston, the liquid solution being dispensed and any solid particulates may be carried away and removed from the pump.

Abstract: A magnetic coupling system may be used in a fluid displacement apparatus to magnetically couple a drive shaft to a piston. The magnetic coupling system may include first and second magnetic couplers at the ends of the drive shaft and piston, respectively. The first magnetic coupler and second magnetic coupler may be configured to exert an attractive force. A bearing between the magnetic couplers reduces friction and side loading.

Abstract: A magnetic coupling system may be used in a fluid displacement apparatus to magnetically couple a drive shaft to a piston. The magnetic coupling system may include first and second magnetic couplers at the ends of the drive shaft and piston, respectively. The first magnetic coupler and second magnetic coupler may be configured to exert an attractive force. A bearing between the magnetic couplers reduces friction and side loading.

Abstract: A magnetic coupling system may be used in a fluid displacement apparatus to magnetically couple a drive shaft to a piston. The magnetic coupling system may include first and second magnetic couplers at the ends of the drive shaft and piston, respectively. The first magnetic coupler and second magnetic coupler may be configured to exert an attractive force. A bearing between the magnetic couplers reduces friction and side loading.

Abstract: In general, a piston-type pump includes a wash flow path that allows a wash liquid such as water to pass through to provide washing and cleaning as the pump operates. The pump may be used in precision liquid dispensing systems and particularly with liquid solutions that have a tendency to precipitate solid particulate. By washing a portion of the pump piston, the liquid solution being dispensed and any solid particulates may be carried away and removed from the pump.

Abstract: A magnetic coupling system may be used in a fluid displacement apparatus to magnetically couple a drive shaft to a piston. The magnetic coupling system may include first and second magnetic couplers at the ends of the drive shaft and piston, respectively. The second magnetic coupler is configured to magnetically engage the first magnetic coupler and configured to mechanically engage the first magnetic coupler if the couplers disengage magnetically.

Abstract: A liquid sealed air displacement apparatus may be used in a fluid transfer device to transfer volumes of fluid. The air displacement apparatus may include a piston and a cylinder defining a displacement chamber for receiving the piston. The air displacement apparatus may be used to displace precise volumes of air into the air displacement chamber. Displacing the air creates a negative pressure in the air displacement chamber (i.e., suction), which may cause a precise volume of fluid to be drawn into the fluid transfer device. The piston and the cylinder may define a diametrical clearance for receiving sealing fluid, which may prevent air leakage and wear.

Abstract: A magnetic coupling system may be used in a fluid displacement apparatus to magnetically couple a drive shaft to a piston. The magnetic coupling system may include first and second magnetic couplers at the ends of the drive shaft and piston, respectively. The first magnetic coupler and second magnetic coupler may be configured to exert an attractive force. A bearing between the magnetic couplers reduces friction and side loading.

Abstract: A magnetic coupling system may be used in a fluid displacement apparatus to magnetically couple a drive shaft to a piston. The magnetic coupling system may include first and second magnetic couplers at the ends of the drive shaft and piston, respectively. The second magnetic coupler is configured to magnetically engage the first magnetic coupler and configured to mechanically engage the first magnetic coupler if the couplers disengage magnetically.

Abstract: The present invention provides systems and methods of dispensing liquids. In one embodiment, the system includes a pump with a removable pump module with at least one displacement piston and at least one piston valve. A motor and base assembly provide the supporting components of the pump which can be used in environments where precise small volumes of ultra-pure liquids must be transferred from a reservoir to a point of use. The preferred embodiment of the system prevents contaminants and air bubbles from being introduced into the liquid to be dispensed by placing a filter across the discharge line downstream from the pump, and providing a separate drawback line for performing the drawback of the liquid in the dispensing nozzle.

Abstract: The present invention provides systems and methods of dispensing liquids. In one embodiment, the system includes a pump with a removable pump module with at least one displacement piston and at least one piston valve. A motor and base assembly provides the supporting components of the pump, which can be used in environments where precise small volumes of ultra-pure liquids must be transferred from a reservoir to a point of use. The preferred embodiment of the system prevents contaminants and air bubbles from being introduced into the liquid to be dispensed by placing a filter across the discharge line downstream from the pump, and providing a separate drawback line for performing the drawback of the liquid in the dispensing nozzle.

Abstract: A rotary reciprocating pumping apparatus is provided with a positive two position adjustment feature which allows the piston stroke to be increased to a maximum and repeatably, automatically, returned to a second calibrated dispensing position. Such rotary reciprocating pump is further provided with an adjustable liquid displacement velocity profile to maintain sufficient velocity of liquid flow at the end of the pump discharge cycle to enable injection of small volumes of liquid through a pump exhaust port, thereby eliminating the inaccurate and time consuming operation of touching off a small volume of liquid as a drop characterizing known rotary reciprocating pumping systems.

Abstract: A rotary/reciprocating liquid dispensing pump for dispensing liquids in the nanoliter range has a narrow radial slot extending longitudinally from an end of a reciprocating, rotating cylindrical piston sliding in a smooth cylindrical bore of a pump housing at a closed end thereof, which slot extends outwardly to the periphery of the piston. The piston is selectively positioned in alignment with one of a plurality of circumferentially spaced small diameter radial passages within the housing opening directly to the cylindrical bore in the path of rotation of said slot. The ports thereof opening to the cylindrical bore are spaced circumferentially a distance in excess of the width of the slot. A linear liquid dispensing pump apparatus including such pump includes a stepping motor and an electromagnetic clutch/braking mechanism concentrically surrounding a lead screw, and the lead screw is threadably engaged with a stepping motor tubular rotor shaft.

Abstract: An electro-optical circuit for detecting fluid in a translucent or a transparent duct or tube, this circuit including an AC activated light emitting diode (LED) for transmitting a narrow beam of light through the tube and a photo transistor detection, sub-circuit activated by the LED light beam, the power to the LED being adjusted to operate the photo transistor of the detection circuit in its unsaturated, active region of operation.