Patents by Inventor Hamilton W. Marshall, Jr.

Hamilton W. Marshall, Jr. has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4076503
    Abstract: An automatic pipetting system for pipetting a measured micro-quantity of reagent into a reaction cup, in which the pipetter is lowered into a reagent bottle, a predetermined amount of reagent drawn in using a positive displacement pump, the pipetter withdrawn from the reagent bottle through an irrigated wiping sponge to accurately control the drop of reagent at its tip, rotated to a position over the cup and lowered thereinto after which the displacement pump expels a measured amount of reagent.
    Type: Grant
    Filed: December 15, 1975
    Date of Patent: February 28, 1978
    Assignee: The Perkin-Elmer Corporation
    Inventors: John G. Atwood, Charles F. DeMey, III, Hamilton W. Marshall, Jr., Lucien C. Ducret
  • Patent number: 4053236
    Abstract: An absorbance measuring photometer, for measuring the absorbance of a sample in a sample cell, in which light of preselected wavelengths from one of two alternately utilizable sources of different wavelengths is formed into a beam and the etendu of the beam defined. The beam is then split into two separate beams one of which is directed through the sample cell onto a first detector and the other of which is passed directly onto a reference detector. The beam is so directed though the sample cell that it does not touch the cell walls and both beams are imaged on their respective detectors so as to be wholly within the photosensitive area thereof.
    Type: Grant
    Filed: July 8, 1976
    Date of Patent: October 11, 1977
    Assignee: The Perkin-Elmer Corporation
    Inventors: John G. Atwood, Hamilton W. Marshall, Jr., Charles F. DE Mey, II
  • Patent number: 4052161
    Abstract: A completely automated kinetic analyzer particularly suited for performing classical kinetic chemistries on an ultra-micro scale. The analyzer comprises a sample preparation unit and a photometric analytical unit. The preparation unit includes a rotationally indexed tray of sample containers presented in timed sequence to a diluter probe which effects dilution of the samples while transferring them sequentially to respective reaction cups, batches of which are contained in magazines and previously filled, by means of an automatic pipetter, with a first reagent. Conveyors move the magazines in stages through the preparation unit, the sample-reagent mixtures meanwhile undergoing preincubation. A second automatic pipetter thereafter adds a second reagent to each cup, in turn the contents of which are then mixed by an automatic stirrer.
    Type: Grant
    Filed: July 10, 1975
    Date of Patent: October 4, 1977
    Assignee: The Perkin-Elmer Corporation
    Inventors: John G. Atwood, Hamilton W. Marshall, Jr., Peter H. Heinz
  • Patent number: 4022240
    Abstract: A sealant system for slide valves used in analysis apparatus and the like in which the slide valves are formed with a channel between the ports in the valve block and the outside thereof, with a sealant liquid supplied under a slight pressure to the channel to seal and lubricate the valve and prevent sticking even after long periods of idleness. The apparatus used to pressurize the sealant liquid is at the same time used to generate a flow of water through a heat exchanger used in the kinetic analysis apparatus.
    Type: Grant
    Filed: August 22, 1974
    Date of Patent: May 10, 1977
    Assignee: The Perkin-Elmer Corporation
    Inventors: Hamilton W. Marshall, Jr., Lucian C. Ducret, John G. Atwood
  • Patent number: 4014612
    Abstract: A highly stable and sensitive photometric apparatus is obtained by combining a sensitive, stable, unchopped, dual-beam optical photometer with an accurate electronic sensing circuit. The circuit includes PIN silicon diode detectors on which the two beams of the photometer are imaged. One beam is a reference to detect light source variations and the other a signal beam passing through the sample cell of the photometer. The PIN diode outputs are inputs to parametric amplifiers. The amplifier outputs are then provided to log taking means which take the logarithms of the two signals and then take the difference of the two logarithms to provide a final output proportional to absorbtion in the cell.
    Type: Grant
    Filed: August 22, 1974
    Date of Patent: March 29, 1977
    Assignee: The Perkin-Elmer Corporation
    Inventors: John G. Atwood, Hamilton W. Marshall, Jr., Charles F. Demey, II, Wilson P. Ralston
  • Patent number: 3948607
    Abstract: An automatic transfer system for transferring a reaction sample to a sample cell in analysis apparatus in which a transfer pump draws in slugs of sample separated by slugs of air, the slugs being obtained through a coordinated probe oscillation, bringing a sample slug into the sample cell and holding it there for measurement, the system further including a wash pump for the depositing wash liquid in the sample cup which is also drawn into the system to flush it out between samples.
    Type: Grant
    Filed: August 22, 1974
    Date of Patent: April 6, 1976
    Assignee: The Perkin-Elmer Corporation
    Inventors: John G. Atwood, Lucien C. Ducret, Hamilton W. Marshall, Jr.