Abstract: A method and apparatus for calibrating a multiple port metering pump includes a graduated scale mounted on the head of the pump and an indicator mounted on the body of the pump, whereby the angular orientation of a plurality of radially extending, sequentially spaced outlet ports may be adjusted relative to the pump piston to calibrate and balance the flow of fluid therethrough.

Abstract: A valveless metering pump includes a simultaneously reciprocating and rotating piston. The pump head includes radially spaced coplanar ports for drawing and dispensing fluids as the piston rotates sequentially past the ports. The reciprocating stroke of the piston is controlled by adjusting the axis of the piston relative to the drive axis. The pump is designed so that the angular relationship of the ports also can be adjusted relative to the piston to balance the output at the sequential ports. The plurality of adjustments provide a valveless, positive displacement metering pump which is reliable and dependable for dispensing precise volumes of fluid through a plurality of outlet ports.

Abstract: A pipette tip for use in automated assay testing systems includes an annular, protruding seal ring on the interior wall of the pipette for engaging a sealing surface on a probe to provide a resilient seal. The pipette tip also includes a positive stop for assuring proper positioning and alignment of the pipette tip on the probe for facilitating mounting of the pipette tip on the probe while minimizing variation in the loading and unloading forces required. Locator surfaces are provided on the exterior of the pipette tip for precisely aligning the pipette tip in the system rack for positioning the pipette tip relative to the probe.

Abstract: A control system for the working piston of a valveless metering pump for the precision delivery of fluids to a plurality of sequentially spaced output ports is adapted to control and alter the speed of rotation of the pump piston depending on predetermined angles of rotation of the piston as it cycles.

Abstract: A valveless, positive displacement metering pump is provided which is capable of either mixing two or more fluids or dividing a fluid from an inflow line into two or more outflow lines. The pump includes a housing which contains a cylindrical working chamber at different radial positions. Three or more passages extend through the housing and communicate with the working chamber. A piston is positioned within the working chamber. The piston includes a duct defined by its outer surface which communicates with one of the passages, depending upon its rotational position. The piston is rotated as it is driven back and forth within the cylinder, thereby causing the duct to sequentially communicate with the passages and the piston to sequentially close the passages. Depending upon the axial direction of movement of the piston, fluid is either pumped into or out of the working chamber as the duct rotates into communication with one of the passages.