Patents by Inventor Duane Douglass

Duane Douglass 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: 4777869
    Abstract: Fluid actuator includes a piston rod comprised of a wound filamentary composite structure to provide an extremely light weight, relatively low cost, envelope efficient design. Attached to the piston rod are one or more non-integral piston heads which are preloaded against one or more ramp surfaces on the exterior of said piston rod. A pair of oppositely facing ramp surfaces may be formed on the piston rod by interspersing filler means between the piston rod fiber layers. Another ramp area may be formed by providing an external groove in the piston rod which is engaged by longitudinally split support shoes that provide an attachment surface for a detachable piston head. An internal ramp may also be provided on the inner diameter of the piston rod adjacent the axial outer end thereof for mating engagement by a conically ramped exterior surface on an internal metal stud used to attach a rod end assembly to the axial outer end of the piston rod.
    Type: Grant
    Filed: March 28, 1986
    Date of Patent: October 18, 1988
    Assignee: Pneumo Abex Corporation
    Inventors: William Dirkin, James N. Tootle, Duane Douglass, Terry L. Benton
  • Patent number: 4697499
    Abstract: Dual tandem composite cylinder assembly includes a cylinder having circumferential or hoop stress windings surrounding a pair of hydraulic chambers in series to react the circumferential loads and prevent diametrical expansion of the hydraulic chambers. Longitudinal tension windings extend over substantially the entire length of the cylinder outwardly of the circumferential windings to react the axial loads which the cylinder must contain. Compressive cylinder composite windings are also provided for carrying compressive loads generated within the cylinder. The hydraulic chambers are desirably lined with removable liner members to facilitate changing of seals and refurbishment of the cylinder.
    Type: Grant
    Filed: August 20, 1984
    Date of Patent: October 6, 1987
    Assignee: Pneumo Corporation
    Inventors: William Dirkin, Duane Douglass, James N. Tootle, Terry L. Benton
  • Patent number: 4685384
    Abstract: Fluid actuator includes a composite cylinder having circumferential hoop stress windings wrapped about a liner member forming the piston chamber wall, and longitudinal tension windings extending from the outboard end of the cylinder along one side thereof and around the inboard end of the cylinder to the other side and back to the outboard end where they are secured to the cylinder. A compression column of composite material may be provided between a cylinder end wall and a permanent structure mount at the inboard end of the cylinder to extend the length of the cylinder to accommodate a tail stock on the piston of a pressure balanced actuator.
    Type: Grant
    Filed: February 28, 1986
    Date of Patent: August 11, 1987
    Assignee: Pneumo Corporation
    Inventors: William Dirkin, Duane Douglass, James N. Tootle, Terry L. Benton