Leslie James Miller
Engineers in San Jose, CA

4797834, Jan 10, 1989

Sep 30, 1986

6/913709

Ronald E. Honganen - Campbell CA
Robert L. Howe - San Ramon CA
Leslie A. Miller - San Jose CA

G06F 1546, F17D 300

364510

An apparatus and method controls a dual piston pump for a liquid chromatography system so as to pump a flow of solvent through the liquid chromatography column at a constant flow rate and with a solvent composition which is substantially equal to the desired solvent composition despite changing conditions of compressibility of the solvent. A computer is used which measures the time it takes the pump shaft to move through an overlap region in the pump cycle when both pistons are simultaneously pumping as normalized to the time taken by the pump to move through a constant velocity portion of the piston travel defined by the user. This time is compared to the time stored in the computer for the particular flow rate used to measure the time defined above for the pump to move through the overlap region for an incompressible solvent at low pressure as normalized to the time taken by the input piston to move through the same user defined segment of the constant velocity portion of the travel of the input piston. The ratio of these two times is then used in an algorithm to derive a correction factor for compressibility. This correction factor is then used to control the flow rate and the makeup of the solvent composition to maintain the correct values over changing conditions of solvent compressibility.

4478095, Oct 23, 1984

Mar 9, 1981

6/241810

Martin P. T. Bradley - Cupertino CA
Leslie A. Miller - San Jose CA
Thomas J. McCall - Fremont CA
Duane L. Middlebusher - San Jose CA

Spectra-Physics, Inc. - San Jose CA

G01N 3504, G01N 3506

7386421

A sampler for taking samples from multiple sources has a fixed, non-moving needle at a sampling station. A sample vial is lifted from a tray at the sampling station. The needle pierces the septum of the vial and enters the sample as the vial is lifted toward the needle. The sample vial is also rotated as it is lifted, and a bar code reader makes a number of spaced apart, helical reads on a bar code label attached to the vial for label identification of the sample. The needle includes an inner, sample needle and an outer, gas-pressurization needle. The sample is withdrawn by the positive displacement of a syringe connected to the sample needle. The combination of the gas pressurization within the vial and the positive displacement of the syringe insures movement of the sample and accurate control of the volume removed independent of the viscosity of the sample. The vial tray mechanism for carrying the sample vials to and from the sample station includes a rotatable platter and four planetary trays carried by and rotatable on the platter. A clutch and brake drive permits the entire tray assembly to be rotated as a unit and also permits rotation of the planetary trays relative to the main platter so that any sample vial can be positioned at the sample station in any desired sequence with respect to the other sample vials.

4797207, Jan 10, 1989

Sep 30, 1986

6/913356

Ronald E. Honganen - Campbell CA
Robert L. Howe - San Ramon CA
Leslie A. Miller - San Jose CA

Spectra Physics, Inc. - San Jose CA

B01D 1508

2101982

There is disclosed herein an apparatus and method for controlling a dual piston pump for a liquid chromatography system so as to pump a flow of solvent through the liquid chromatography column at a constant flow rate and with a solvent composition which is substantially equal to the desired solvent composition despite changing conditions of compressibility of the solvent. The control system uses a computer which measures the time it takes the pump shaft to move through an overlap region in the pump cycle when both pistons are simultaneously pumping as normalized to the time taken by the pump to move through a constant velocity portion of the piston travel defined by the user. This time is compared to the time stored in the computer for the particular flow rate used to measure the time defined above for the pump to move through the overlap region for an incompressible solvent at low pressure as normalized to the time taken by the input piston to move through the same user defined segment of the constant velocity portion of the travel of the input piston. The ratio of these two times is then used in an algorithm to derive a correction factor for compressibility. This correction factor is then used to control the flow rate and the makeup of the solvent composition to maintain the correct values over changing conditions of solvent compressibility.

5183486, Feb 2, 1993

Dec 4, 1990

7/622999

Ronald A. Gatten - Pleasanton CA
Leslie A. Miller - San Jose CA
Thomas J. McCall - Fremont CA
Vance J. Nau - Cupertino CA

Spectra-Physics, Inc. - San Jose CA

B01D 1900

55159

Methods and apparatus for effective vacuum degassing of a liquid are provided for liquid chromatography. The bottles with the liquid are mounted above the vacuum degassing unit to provide a head pressure to the LC pump and physical stability to the bottles. The liquid is heated in the vacuum chamber by a radiator of electromagnetic energy (in one embodiment, infra-red light). Alternatively the liquid is heated before it enters the vacuum chamber. The liquid is in an agitated state in the vacuum chamber. In one variation, the liquid is conducted through the vacuum chamber through tubes wound around bobbins so as to expose a greater portion of the surface area of the tubes to vacuum. Circuitry stops the vacuum pump for a duration of a chromatographic run. The circuitry controls the LC pump and the vacuum pump so as to optimize the chromatographic conditions in the liquid chromatography analytical system. The autosampler of the analytical system includes a vacuum degasser for degassing the resident solvents of the autosampler.

4622457, Nov 11, 1986

Jul 3, 1984

6/627442

Martin P. T. Bradley - Cupertino CA
Leslie A. Miller - San Jose CA
Thomas J. McCall - Fremont CA
Duane L. Middlebusher - San Jose CA
John H. Henselman - Pleasanton CA

Spectra-Physics, Inc. - San Jose CA

G06K 710

235464

A sampler for taking samples from multiple sources has a fixed, non-moving needle at a sampling station. A sample vial is lifted from a tray at the sampling station. The needle pierces the septum of the vial and enters the sample as the vial is lifted toward the needle. The sample vial is also rotated as it is lifted, and a bar code reader makes a number of spaced apart, helical reads on a bar code label attached to the vial for label identification of the sample. The needle includes an inner, sample needle and an outer, gas-pressurization needle. The sample is withdrawn by the positive displacement of a syringe connected to the sample needle. The combination of the gas pressurization within the vial and the positive displacement of the syringe insures movement of the sample and accurate control of the volume removed independent of the viscosity of the sample. The vial tray mechanism for carrying the sample vials to and from the sample station includes a rotatable platter and four planetary trays carried by and rotatable on the platter. A clutch and brake drive permits the entire tray assembly to be rotated as a unit and also permits rotation of the planetary trays relative to the main platter so that any sample vial can be positioned at the sample station in any desired sequence with respect to the other sample vials.

4552513, Nov 12, 1985

Mar 7, 1983

6/472668

Leslie A. Miller - San Jose CA
Thomas J. McCall - Fremont CA

Spectra-Physics, Inc. - San Jose CA

F04B 4906, F04B 300

417 18

A multiple piston assembly pump of the kind which provides an overlap between the flow output of the piston assemblies during a portion of the strokes of the piston assemblies incorporates a method and apparatus for reducing pulsations in the flow during the time when the pump is changing over from one piston pumping to the other piston pumping. A first fast control loop responds to pump output pressure and is operatively associated with a second slow control loop which responds to average pump speed. A sudden pump speed change is detected, and the pump is run in a constant pressure mode until the speed returns to normal.

4352636, Oct 5, 1982

Apr 14, 1980

6/139648

Williams G. Patterson - Palo Alto CA
Allen B. Rochkind - Santa Cruz CA
Leslie A. Miller - San Jose CA
Martin P. T. Bradley - Cupertino CA

Spectra-Physics, Inc. - San Jose CA

F04B 4906

417 22

A pump for producing a substantially smooth and continuous outflow of liquid at relatively high pressure has two piston assemblies flow connected in series. The first piston assembly includes a pressure piston having a long suction stroke and a relatively short and abrupt expulsion stroke. A valve at the inlet of the pressurization piston allows flow to enter (but not exit), and a valve at the outlet of the pressurization piston allows flow to exit (but not enter). The second piston assembly includes a damper piston which functions as a mechanically driven damper to smooth the outflow from the pressure piston. This smoothing is accomplished by storing of the liquid displaced by the expulsion stroke of the pressure piston and then delivering the stored pressurized liquid to the pump outlet during the suction stroke of the pressure piston. The drive for the pistons is constructed to produce an increased outflow of pressurized liquid for a short interval at the beginning of the expulsion stroke of the pressure piston to compensate for compressibility of the liquid at high pressure. At low pressure, the stepper motor drive is slowed down in response to the sensing of the increase of the outflow during this short interval to maintain the outflow smooth and continuous during this part of the cycle of operation.

5483843, Jan 16, 1996

Jun 1, 1992

7/891869

Leslie A. Miller - San Jose CA
Thomas J. McCall - Fremont CA
Samuel A. Marquiss - Santa Clara CA
Douglas H. Smith - Los Altos CA
Richard F. Johnson - San Jose CA

Thermo Separation Products Inc. - Fremont CA

G01N 3500

7386423

A vial transport apparatus which is capable of storing and retrieving samples and then transporting them from one location in a sampling system to another without the complexity and expense of robotic arms or gripper elements is provided. A passive hook arrangement is utilized to engage the vials for transport and can be operated using a standard three motor system for transport in the X, Y, and Z directions. The hook supports the vial from beneath and at least partially surrounds the vial to entrap it during transport thereof.