Patents by Inventor Donald A. Durran

Donald A. Durran 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: 5833204
    Abstract: The present invention provides improvements in the design of radial flexures and beam-columns used in vibration isolation systems which rely on a principle of loading a particular elastic structure which forms the isolator or a portion of it to approach the elastic structure's point of elastic instability. The improved radial flexure includes a region along the flexure in which there is reduced stiffness than the stiffness substantially along the length of the flexure. In one preferred form of the invention, the region of reduced stiffness is created by machining or forming a notch near each end of the flexure. Likewise, the improved design of the beam-column includes a region in which the stiffness of the beam-column in less than the stiffness along substantially the length of the beam-column. In one preferred embodiment, the region of reduced stiffness of the beam-column is formed by machining or otherwise forming notches near the ends of the beam-column.
    Type: Grant
    Filed: March 17, 1997
    Date of Patent: November 10, 1998
    Assignee: Minus K Technology, Inc.
    Inventors: David L. Platus, Donald A. Durran
  • Patent number: 5794909
    Abstract: An auto-adjust apparatus adjusts a vibration isolator to help accommodate varying weight loads and other effects which can cause the isolator to go out of adjustment, such as variations caused by changes in ambient temperature and creep of the isolator's main support spring. A small secondary spring is positioned in parallel with the main support spring of the isolator and is precompressed such that its compression increases the load on the main support spring by a small amount. An increase in the compression of this secondary spring will cause an increase in the load on the main support spring. Similarly, a decrease in the compression on this secondary spring will cause a decrease in the load on the main support spring. Sensors for sensing a deviation in the equilibrium position of the object relative to the base from its optimum equilibrium position are provided and generate an electrical signal indicating such deviations.
    Type: Grant
    Filed: September 16, 1996
    Date of Patent: August 18, 1998
    Assignee: Minus K Technology, Inc.
    Inventors: David L. Platus, Donald A. Durran
  • Patent number: 5669594
    Abstract: An improved version of vibration isolation systems using negative stiffness incorporates a payload and payload platform on just one 6-DOF isolator in a unique and innovatively compact configuration. The isolator includes a platform supported on an assembly of independently acting flexure mechanisms which are connected in serial fashion, tilt on top of horizontal on top of vertical, and in turn connected a base. Proper arrangement of the mechanisms and the payload/platform center of mass provides highly effective decoupled isolator performance. In addition, an innovative flexure preloading method which significantly improves vertical isolation performance is incorporated. This method can be used with prior (unsymmetric) designs or combined with a set of shear flexures in an innovative symmetric arrangement described below to provide more assurance of ideal decoupled response to mutually perpendicular base excitation input.
    Type: Grant
    Filed: May 3, 1995
    Date of Patent: September 23, 1997
    Assignee: Minus K Technology, Inc.
    Inventors: David L. Platus, Donald A. Durran
  • Patent number: 4319839
    Abstract: A beam alignment system having a source for producing a first beam of electromagnetic radiation considered an alignment or reference beam, a source for producing a second beam of electromagnetic radiation to be aligned with the first beam and pair of rotating mirrors capable of being optically interposed at different times across the optical path of the first and second beams. The axes of rotation of the pair of mirrors are transverse to each other in order to enable each mirror to provide alignment information about the beams with respect to two different planes. The alignment information is indicative of a time difference between the reception by a first detector of the reflected first beam and the reflected second beam from the first mirror and a time difference between the reception by a second detector of the reflected first beam and the reflected second beam from the second mirror.
    Type: Grant
    Filed: March 27, 1980
    Date of Patent: March 16, 1982
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventor: Donald A. Durran
  • Patent number: 4213102
    Abstract: A system for generating fluorine for use as a gaseous reactant in a chemical laser from a storable gas supply of NF.sub.3.
    Type: Grant
    Filed: March 21, 1978
    Date of Patent: July 15, 1980
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Walter R. Warren, Jr., Donald A. Durran, Donald J. Spencer