Patents by Inventor David W. Doll

David W. Doll 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: 8812069
    Abstract: A device and method for making a persistent joint allowing end terminations of superconducting MgB2 wire to be joined with a superconducting bridge. Superconducting electromagnetic coils may be joined in series or joining of coil assemblies to current sources and the two ends of a persistent switch. The device includes wire filaments with end preparation exposing reacted MgB2, inserted into a block and surrounded with Mg+B and/or MgB2 in powder, solid, slurry or sol-gel form and subsequently reacted to establish a bridge of superconducting MgB2 electrically connecting the superconducting MgB2 wires. Autonomous operation of the superconducting background magnet coils in magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR) devices are allowed, or similar devices where autonomous operation of an MgB2 based superconducting magnet is required. The low resistant joint will also be beneficial for other superconducting applications such as fault current limiters, motors, generators, etc.
    Type: Grant
    Filed: January 25, 2010
    Date of Patent: August 19, 2014
    Assignee: Hyper Tech Research, Inc
    Inventors: David W. Doll, Michael J. Tomsic
  • Publication number: 20100190649
    Abstract: A device and method for making a persistent joint allowing end terminations of superconducting MgB2 wire to be joined with a superconducting bridge. Superconducting electromagnetic coils may be joined in series or joining of coil assemblies to current sources and the two ends of a persistent switch. The device includes wire filaments with end preparation exposing reacted MgB2, inserted into a block and surrounded with Mg+B and/or MgB2 in powder, solid, slurry or sol-gel form and subsequently reacted to establish a bridge of superconducting MgB2 electrically connecting the superconducting MgB2 wires. Autonomous operation of the superconducting background magnet coils in magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR) devices are allowed, or similar devices where autonomous operation of an MgB2 based superconducting magnet is required. The low resistant joint will also be beneficial for other superconducting applications such as fault current limiters, motors, generators, etc.
    Type: Application
    Filed: January 25, 2010
    Publication date: July 29, 2010
    Inventors: David W. Doll, Michael J. Tomsic
  • Patent number: 4598936
    Abstract: A remotely operable and maintainable vacuum joint closure mechanism for a noncircular aperture is disclosed. The closure mechanism includes an extendible bellows coupled at one end to a noncircular duct and at its other end to a flange assembly having sealed grooves for establishing a high vacuum seal with the abutting surface of a facing flange which includes an aperture forming part of the system to be evacuated. A plurality of generally linear arrangements of pivotally coupled linkages and piston combinations are mounted around the outer surface of the duct and aligned along the length thereof.
    Type: Grant
    Filed: February 22, 1984
    Date of Patent: July 8, 1986
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: David W. Doll, E. Randolph Hager
  • Patent number: 4532101
    Abstract: A limiter blade for a large tokomak fusion reactor includes three articulated blade sections for enabling the limiter blade to be adjusted for plasmas of different sizes. Each blade section is formed of a rigid backing plate carrying graphite tiles coated with titanium carbide, and the limiter blade forms a generally elliptic contour in both the poloidal and toroidal directions to uniformly distribute the heat flow to the blade. The limiter blade includes a central blade section movable along the major radius of the vacuum vessel, and upper and lower pivotal blade sections which may be pivoted by linear actuators having rollers held to the back surface of the pivotal blade sections.
    Type: Grant
    Filed: October 21, 1982
    Date of Patent: July 30, 1985
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: David W. Doll
  • Patent number: 4476022
    Abstract: A module for use in separating a permeate from a fluid feed mixture. The module employs a serrated product tube with a plurality of perforations or apertures through the serrations to the inside of the tube. The serrations take the form of a helix or a grid. A product spacer with protruding ribs on one surface is folded over the product tube with the ribs on the opposite side of the serrations of the tube, and extending a predetermined length for laminating with additional spacer material and a membrane with a highly porous backing. The free ends of the membrane are sealed together to form an envelope enclosing the product spacer. First and second brine spacers having channels parallel with the axis of the tube separate the envelope portion of the product spacer and membrane so that when the membrane and spacers are spirally wound about the tube, each layer of product spacer and membrane have first and second brine spacers therebetween with the channels of the first and second brine spacers opposing.
    Type: Grant
    Filed: March 11, 1983
    Date of Patent: October 9, 1984
    Inventor: David W. Doll
  • Patent number: 4001078
    Abstract: A nuclear reactor system is described in which flexible control rods are used to enable insertion of the control rods into guide holes in the core which are distributed over an area larger than the cross section of the control rod penetration in the reactor pressure vessel. Guide tubes extend from the penetration and fan out to the guide holes for guiding the control rods from the penetration to the guide holes.
    Type: Grant
    Filed: March 7, 1975
    Date of Patent: January 4, 1977
    Assignee: General Atomic Company
    Inventor: David W. Doll