The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 17, 1998
Filed:
Mar. 20, 1995
Carl D Beckett, Vancouver, WA (US);
Kevin O'Hara, Vancouver, WA (US);
Daniel B Olsen, Vancouver, WA (US);
Micropump Corporation, Portland, OR (US);
Abstract
A reciprocating piston pump provides pulsation free delivery of liquid. It is suitable for use in compact environments or for the delivery of small amounts of liquid, as in chromatographic analysis devices. The pump includes two pistons with pumping chambers that are alternately connected to inflow and outflow lines through a control valve. The control valve moves between a first position in which inflow is directed to the first piston chamber and outflow to the second piston chamber, and a second position in which outflow is directed to the first piston chamber and inflow is directed to the second piston chamber. Each outflow pulse from the piston is sustained longer than each inflow pulse, and the outflow pulses are staggered and partially superimposed to provide substantially pulsation free delivery of liquid from the pump. A rotating cam moves the pistons of the pumps and the control valve between their operating positions described above. The cam rotates at a constant speed around an axis that is parallel to the axis of movement of the piston pumps.