Patents by Inventor Michael C. Frengley

Michael C. Frengley 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).

  • Method of making a leading edge weight retention assembly for a helicopter rotor
    Patent number: 5621967
    Abstract: A method for making helicopter rotor blades includes wrapping a prepreg strap around the conical or cylindrical outboard end of each weight segment. The weight segment is then placed in the rotor blade spar and goes through the spar cure cycle with it. Primary retention is provided by adhesive bonding between the weight and the spar. Secondary retention is by hoop tension in the strap, acting through interlaminar shears at the co-cured interface with the spar.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: April 22, 1997
    Assignee: McDonnell Douglas Helicopter Co.
    Inventors: Michael C. Frengley, Thu N. Vu
  • Leading edge weight retention assembly for a helicopter rotor
    Patent number: 5462409
    Abstract: Leading edge weights for helicopter rotor blades are required to provide blade chordwise balance and maintain rotor inertia. Provision for retention of the leading edge weights in a high centrifugal force field, after failure of the primary adhesive bond, is necessary. The invention discloses wrapping a prepreg strap around the conical or cylindrical outboard end of each weight segment. The weight segment is then placed in the rotor blade spar and goes through the spar cure cycle with it. Primary retention is provided by adhesive bonding between the weight and the spar. Secondary retention is by hoop tension in the strap, acting through interlaminar shears at the co-cured interface with the spar.
    Type: Grant
    Filed: March 18, 1994
    Date of Patent: October 31, 1995
    Assignee: McDonnell Douglas Helicopter Co.
    Inventors: Michael C. Frengley, Thu N. Vu