Patents by Inventor David M. Welsh

David M. Welsh 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: 5024158
    Abstract: A method of blasting cap-sensitive, non-nitroglycerine-sensitized explosives and an initiating assembly for use in the method are provided. The method comprises initiating a column of the explosives by directing two radial/forward shock forces from an initiator assembly substantially simultaneously along the column of the explosives towards each end of the column. The initiating assembly of the invention comprises at least two initiators assembled side-by-side so that their explosive ends are opposite. A moulded plastics holder (6) for holding two blasting caps (1, 8) in the required spatial relationship is also described.
    Type: Grant
    Filed: May 17, 1990
    Date of Patent: June 18, 1991
    Assignee: Imperial Chemical Industries PLC
    Inventors: David L. Kennedy, Donald C. True, David M. Welsh
  • Patent number: 4947751
    Abstract: A method of blasting cap-sensitive, non-nitroglycerine-sensitized explosives and an initiating assembly for use in the method are provided. The method comprises initiating a column of the explosives by directing two radial/forward shock forces from an initiator assembly substantially simultaneously along the column of the explosives towards each end of the column. The initiating assembly of the invention comprises at least two initiators assembled side-by-side so that their explosive ends are opposite. A moulded plastics holder (6) for holding two blasting caps (1, 8) in the required spatial relationship is also described.
    Type: Grant
    Filed: February 3, 1989
    Date of Patent: August 14, 1990
    Assignee: Imperial Chemical Industries, PLC
    Inventors: David L. Kennedy, Donald C. True, David M. Welsh
  • Patent number: 4292896
    Abstract: An improved cord-like detonating device is provided for use in non-electric blasting methods. The device comprises a substantially standard detonating cord length wherein a central longitudinal core of the cord consists of a hollow, low energy shock wave conductor. The device has particular utility in long hole blasting with toe priming. Initiating energy can be transmitted down the hole to the toe primer charge through the low energy shock wave conductor. The detonating primer initiates the outer detonating cord sheath which transmits energy to set off additional primer charges attached thereto.
    Type: Grant
    Filed: April 21, 1980
    Date of Patent: October 6, 1981
    Assignee: CXA Ltd./CXA Ltee
    Inventors: William B. Morrey, David M. Welsh
  • 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