Patents by Inventor Randolph T. Johnson

Randolph T. 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: 8545646
    Abstract: The present disclosure relates to a high-density rocket propellant and associated recoilless launching systems and methods with tungsten powder added providing substantial mass to the propellant for additional impulse, absorption of sound, optimization of back blast and carry weight, and the like. In an exemplary embodiment, the high-density rocket propellant includes tungsten mass percentages of between about 70%-about 80%, equivalent to about 17%-about 26% by volume.
    Type: Grant
    Filed: September 24, 2009
    Date of Patent: October 1, 2013
    Assignee: The United States of America as Represented by the Secretary of the Navy
    Inventors: Matthew J. Sanford, Randolph T. Johnson, Paul G. Wallman, Diana O. Bragunier, Stephen N. Stiles
  • Patent number: 6629416
    Abstract: An aerospike nozzle includes a nozzle body and a spike, the nozzle body and the spike defining a generally annular gas flow channel therebetween; the spike comprising an upper, generally conical section having a decreasing diameter in a downstream direction; a middle, generally cylindrical section having a generally constant diameter; and a lower, generally conical section having a decreasing diameter in a downstream direction; a shroud disposed radially outward of the spike and longitudinally downstream of the nozzle body, the shroud comprising a first generally cylindrical section and, downstream of the first section, a second generally concave section; a plurality of struts connected between the spike and the shroud; an ambient air inlet defined between the nozzle body and the shroud; a mixing and combustion chamber defined between the spike and the first section of the shroud; and an expansion chamber defined between the spike and the second section of the shroud.
    Type: Grant
    Filed: April 25, 2002
    Date of Patent: October 7, 2003
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Randolph T. Johnson
  • Patent number: 6354075
    Abstract: The present invention comprises a direct replacement for a charge support spacer currently used in rocket motors. The present invention comprises a vented spacer that cools combustion gases through contact and expansion prior to equalizing pressure by transferring these gases from the inside of the propellant grain to the outside of the grain. The vented spacer takes gases from combustion of the propellant from the core flow inside the propellant grain and cools these gases by contact with and ablation of the spacer material. The gases are cooled to the point that they present no hazard to the rocket motor casing or the outside of the propellant grain. The vented spacer accomplishes these tasks in the same amount of area as the current charged support spacer.
    Type: Grant
    Filed: September 27, 2000
    Date of Patent: March 12, 2002
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Randolph T. Johnson, Gerald L. Armstrong, Joseph J. Dulcey
  • Patent number: 6321656
    Abstract: A container subject to damage through inadvertent overheating and pressure build up such as a rocket casing containing a propellant which can be subjected to damage or inadvertent firing when the ignition temperature is achieved inadvertently includes a thermally actuated release mechanism. The rocket casing includes two sections which are mechanically latched. A thermally responsive material such as Nitinol is provided in a shape such that upon being subjected to a predetermined transition temperature lower than the ignition temperature of the rocket propellant, it changes shape so as to mechanically unlatch the rocket casing sections.
    Type: Grant
    Filed: March 22, 2000
    Date of Patent: November 27, 2001
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Randolph T. Johnson