Abstract: A pair of dual chamber mixing pumps are combined which allow for a constant dispense rate profile using motor speed modulation. Each pump is divided into two chambers, the proximal chamber and the distal chamber. The chambers are defined in part by a piston having proximal and distal ends and recessed sections. The pump utilizes one common driving mechanism to axially rotate and laterally reciprocate the piston to provide continuous pumping of fluids with reduced pulsations. Each fluid enters through its own pump inlet and outlet. The pumps are operated 90° out of phase with respect to each other.

Abstract: A combination manifold and nozzle closure system is disclosed. The closure system limits exposure of the nozzle outlets to air between dispenses or between uses. Manifold accommodates a plurality of nozzles. Each nozzle includes a nozzle outlet extending beyond an end of the manifold. An actuator shaft passes through the manifold and is connected to a plate at its distal end with a film disposed between the plate and the nozzle outlets. An actuator moves the actuator shaft from a closed position where the film engages the nozzle outlets and the plate is disposed just below the nozzles to an open position where the film and plate have been pulled upward beyond the nozzle outlets. The plate includes a plurality of openings and the film includes a plurality of valves each opening in the plate is in alignment with a valve and each valve is in alignment with one of the nozzle outlets.