Patents by Inventor David J. Welburn

David J. Welburn 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: 5509355
    Abstract: A low energy fuse is extruded as a single ply primary tube 1 from a plastic resin blend with particulate energetic material 2 being internally distributed in a manner known per se, said resin blend comprising a major amount of an orientable polymer, for example, linear low density polyethylene to provide structural integrity and a minor amount of a modifier to impart enhanced particle retentive properties to the tube and preferably also containing a polymer or copolymer to impart melt strength and aid in tube extrusion.
    Type: Grant
    Filed: August 19, 1992
    Date of Patent: April 23, 1996
    Assignee: Imperial Chemical Industries PLC
    Inventors: Ronald F. Stewart, David J. Welburn, David M. Welsh, Robert C. Greenhorn
  • Patent number: 5317974
    Abstract: A low energy fuse is extruded as a single ply primary tube 1 from a plastic resin blend with particulate energetic material 2 being internally distributed in a manner known per se, said resin blend comprising a major amount of an orientable polymer, for example, linear low density polyethylene to provide structural integrity and a minor amount of a modifier to impart enhanced particle retentive properties to the tube and preferably also containing a polymer or copolymer to impart melt strength and aid in tube extrusion.
    Type: Grant
    Filed: August 17, 1992
    Date of Patent: June 7, 1994
    Assignee: Imperial Chemical Industries PLC
    Inventors: Ronald F. Stewart, David J. Welburn, David M. Welsh, Robert C. Greenhorn
  • Patent number: 4699059
    Abstract: A modified explosive shock tube is provided which has a lateral energy output and hence may be used as a trunk line in a non-electric blasting network. The modified shock tube comprises a hollow, flexible plastic tube having a layer of energy-producing material on its inner surface and also having at intervals along its length, cuts or slits which penetrate the tube wall. The area of the slits has an overcovering of a waterproof material. When energized, the tube will burst at the area of the slits to release energy in a direction lateral to the tube axis.
    Type: Grant
    Filed: October 14, 1986
    Date of Patent: October 13, 1987
    Assignee: CXA Ltd.
    Inventors: George G. Kelly, David J. Welburn
  • Patent number: 4493261
    Abstract: Low energy explosive shock tubing is provided which consists of a two-ply, inner and outer layer plastic tube having a plurality of lengthwise textile filaments bonded into the interface between the plastic layers. The textile filaments are chosen for their low elongation properties and the resultant shock tube resists stretching especially in warm borehole environments.
    Type: Grant
    Filed: November 2, 1983
    Date of Patent: January 15, 1985
    Assignee: CXA Ltd./CXA LTEE
    Inventors: James R. Simon, David J. Welburn
  • Patent number: RE37689
    Abstract: A low energy fuse in extruded as a single ply primary tube 1 from a plastic resin blend with particulate energetic material 2 being internally distributed in a manner known per se, said resin blend comprising a major amount of an orientable polymer, for example, linear low density polyethylene to provide structural integrity and a minor amount of a modifier to impart enhanced particle retentive properties to the tube and preferably also containing a polymer or copolymer to impart melt strength and aid in tube extrusion.
    Type: Grant
    Filed: April 22, 1998
    Date of Patent: May 7, 2002
    Assignee: Orica Explosives Technology Pty. Ltd.
    Inventors: Ronald F. Stewart, David J. Welburn, David M. Welsh, Robert C. Greenhorn