Patents by Inventor Donald R. Johnson

Donald R. Johnson 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: 4273015
    Abstract: A novel punch for employment in a machine utilizing a punch ring containing a number of spaced, radially-arrayed holes in which the punches are secured, with the punch ring being used in cooperative relation with a die ring employing a number of dies corresponding to the number of punches used. During synchronous rotation of the punch ring and the die ring, each punch interacts each time with a corresponding die, with this arrangement making it possible for the edges of a continuous roll of paper or the like destined to be used in a computer or other type of business machine to be rapidly and effectively punched.
    Type: Grant
    Filed: June 4, 1979
    Date of Patent: June 16, 1981
    Inventor: Donald R. Johnson
  • Patent number: 4214993
    Abstract: An apparatus for separating fluids is formed essentially of three pieces which may be nested together to form a stacked array. The three pieces are a cap, an extraction cartridge housing a separating column, and a primary recovery cup. A secondary recovery cup may also be nested onto the lower end of the waste cup. The primary recovery cup has interior flanges for positioning and protecting the bottom end of the column against damage. Each of the elements has an enlarged upper portion forming an exterior step which facilitates mounting in the swinging bucket of a centrifuge. The column itself may comprise particles of a suitable separatory material with the top and the bottom of the particles retained by porous supports.
    Type: Grant
    Filed: April 3, 1978
    Date of Patent: July 29, 1980
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Jesse G. Forsythe, Jr., Donald R. Johnson, Linda M. St. Onge
  • Patent number: 4190530
    Abstract: Samples to be analyzed, such as physiological fluids (blood, urine, etc.) may be processed using centrifugal techniques. The sample is centrifugally passed through a separation column to extract the desired component from the aqueous phase. Next, the extracted component is washed free of extraneous materials and then eluted from the separating column by centrifugally passing a suitable solvent therethrough. The aqueous phase and extracted components are collected in separate containers.To facilitate this method, an apparatus is provided that accommodates switching between fluid flow paths in a centrifuge. The centrifuge utilizes a swinging bucket rotor which contains a separating column, the top end of which employs a fluid reservoir for holding the sample to be extracted. Fluids are passed through the separating column (a first flow path) from a central distributor in the centrifuge rotor while in operation.
    Type: Grant
    Filed: April 3, 1978
    Date of Patent: February 26, 1980
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Jesse G. Forsythe, Jr., Donald R. Johnson, Linda M. St. Onge
  • Patent number: 4066412
    Abstract: An apparatus for automatically performing analytic procedural steps on a fluid contained in a disposable deformable test pack. The apparatus consists of a means for filling the test pack with sample fluid, a means for controlling the environment of the test pack, a means for initiating reactions within the test pack, a means for analyzing the fluid in the test pack, and a transport means designed to hold the test pack and to transport it between the various operating stations. Associated circuitry combining method switchng and control logic make the operation of the instrument fully automatic.
    Type: Grant
    Filed: August 16, 1968
    Date of Patent: January 3, 1978
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Donald R. Johnson, Richard G. Nadeau, Gerrit Nieuweboer, William L. Truett
  • Patent number: 3940050
    Abstract: Disclosed herein is an improved method for joining diamond to metal using a gold-tantalum or gold-niobium solder. The method utilizes powdered material, and a clamp to keep the diamond in place during the soldering step. The article produces has higher mechanical stability than articles produced by known procedures.
    Type: Grant
    Filed: October 4, 1974
    Date of Patent: February 24, 1976
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Donald R. Johnson, James R. Sawers, Jr.
  • Patent number: RE29725
    Abstract: Performing analytical tests more easily, quickly and accurately by using a specially designed pouch-like container of pliable material. The container has within it a plurality of compartments, each compartment being capable of containing a different reagent and each compartment also being capable of releasing its contained reagent, independently of any other reagents present in the other compartments, into the area of the container not occupied by compartments. This latter area of the container is also adapted to receive the test sample for reaction with any single reagent or any combination of reagents released from the compartments.
    Type: Grant
    Filed: May 7, 1970
    Date of Patent: August 8, 1978
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Donald R. Johnson, Richard G. Nadeau, Gerrit Nieuweboer, William L. Truett