Patents by Inventor Don Christensen

Don Christensen 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: 7578452
    Abstract: A cured ablative composite assembly comprises a housing enclosing a pair of ablative composite sub-assemblies joined by a film adhesive. The cured ablative composite assembly is made by surface treating both ablative composite sub-assemblies in preparation for joining; coupling one ablative composite sub-assembly to another ablative composite sub-assembly with a film adhesive and enclosing the uncured ablative composite assembly within a housing; and depositing the combination of the housing and uncured ablative composite assembly in a ventilated oven with a load applied to the combination housing and uncured ablative composite assembly. The film adhesive is cured providing a portion of a hot gas valve suitable for use in tactical missiles. The film adhesive does not erode at the high temperatures (5000° F.) encountered in hot gas rocket exhausts, thereby providing a seal that offers high strength, pressure-tight joints.
    Type: Grant
    Filed: August 27, 2003
    Date of Patent: August 25, 2009
    Assignee: Honeywell International Inc.
    Inventors: Jason Gratton, Don Christensen, John Perek
  • Publication number: 20050044709
    Abstract: A cured ablative composite assembly comprises a housing enclosing a pair of ablative composite sub-assemblies joined by a film adhesive. The cured ablative composite assembly is made by surface treating both ablative composite sub-assemblies in preparation for joining; coupling one ablative composite sub-assembly to another ablative composite sub-assembly with a film adhesive and enclosing the uncured ablative composite assembly within a housing; and depositing the combination of the housing and uncured ablative composite assembly in a ventilated oven with a load applied to the combination housing and uncured ablative composite assembly. The film adhesive is cured providing a portion of a hot gas valve suitable for use in tactical missiles. The film adhesive does not erode at the high temperatures (5000° F.) encountered in hot gas rocket exhausts, thereby providing a seal that offers high strength, pressure-tight joints.
    Type: Application
    Filed: August 27, 2003
    Publication date: March 3, 2005
    Inventors: Jason Gratton, Don Christensen, John Perek
  • Patent number: 5187987
    Abstract: Apparatus is disclosed for measuring creep stiffness of a specimen, for example, asphalt cement, or other viscoelastic material, having a flexural modulus greater than approximately 1,000 psi. The specimen and the lower part of a loading mechanism are submerged in a constant temperature coolant thereby providing buoyant support to the specimen, preventing it from deflecting under its own weight, as well as providing means for controlling the test temperature. The coolant temperature is maintained to within approximately +/-0.1.degree. C. of a desired temperature. The specimen, having known dimensions, is supported within the coolant on two spaced apart support members. A loading head actuated by an air bearing/pneumatic piston mechanism engages the specimen midway between the two support members. The deflection of the specimen is measured with an LVDT and the load imparted to the specimen by a load cell provided under at least one of the specimen support members.
    Type: Grant
    Filed: November 19, 1991
    Date of Patent: February 23, 1993
    Assignee: The Pennsylvania Research Corporation
    Inventors: David A. Anderson, John G. Witzel, Don Christensen, Hussain Bahia