Daniel I Olsen

US Patent:

57331057, Mar 31, 1998

Filed:

Mar 19, 1996

Appl. No.:

8/618367

Inventors:

Carl D. Beckett - Vancouver WA
Kevin D. O'Hara - Washougal WA
Daniel B. Olsen - Fort Collins CO
Steven E. Soar - Vancouver WA
Glenn E. Siemer - Vancouver WA

Assignee:

Micropump, Inc. - Vancouver WA

International Classification:

F04B 112

US Classification:

417269

Abstract:

A reciprocating piston pump provides pulseless 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 pulseless 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.

US Patent:

57185700, Feb 17, 1998

Filed:

Mar 20, 1995

Appl. No.:

8/407405

Inventors:

Carl D. Beckett - Vancouver WA
Kevin O'Hara - Vancouver WA
Daniel B. Olsen - Vancouver WA

Assignee:

Micropump Corporation - Portland OR

International Classification:

F16H 3910

US Classification:

417517

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.