Patents by Inventor Frederick J. Perry

Frederick J. Perry 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).

  • Rotary blades
    Patent number: 5492448
    Abstract: A rotary blade includes a fixed boundary layer control device extending spanwise on a lower surface adjacent the trailing edge to improve the lift/thrust characteristics of the blade especially at positive incidence angles. It was discovered that expected detrimental effects at zero/negative incidence did not materialize and the reasons are identified. Such blades are particularly useful for helicopter sustaining and anti-torque rotors.
    Type: Grant
    Filed: March 8, 1994
    Date of Patent: February 20, 1996
    Assignee: Westland Helicopters Limited
    Inventors: Frederick J. Perry, Alan Brocklehurst
  • Helicopter rotor blade with improved performance characteristics
    Patent number: 5246344
    Abstract: In a helicopter rotor blade having a root end for attachment to a rotor head, a central portion of constant chord dimension and a tip portion having a chord dimension greater than that of the central portion, an outboard region of the central portion has a negative basic pitching moment coefficient, an inboard region of the central portion has a basic pitching moment coefficient more positive than that of the outboard region and the tip portion has a positive basic pitching moment coefficient.
    Type: Grant
    Filed: June 9, 1992
    Date of Patent: September 21, 1993
    Assignee: Westland Helicopters Limited
    Inventor: Frederick J. Perry
  • Helicopter rotor blades
    Patent number: 5205715
    Abstract: Flow separation behind the notch region of a swept tip of a helicopter rotor blade is reduced by a plurality of boundary layer control vanes located adjacent a forwardly swept leading edge portion forming the notch region.
    Type: Grant
    Filed: October 10, 1991
    Date of Patent: April 27, 1993
    Assignee: Westland Helicopters, Ltd.
    Inventors: Frederick J. Perry, Nicholas C. G. Isaacs, Alan Brocklehurst
  • Helicopter rotor blades
    Patent number: 5199851
    Abstract: A helicoper rotor blade includes at its outer end a tip vane having a mean chord length greater than fifty percent of a chord length of a blade central portion and a span length greater than fifty percent of the blade chord which in operation generates two approximately equal strength tip vortices to reduce an acoustic impulse and a resulting noise known as blade slap.
    Type: Grant
    Filed: October 23, 1991
    Date of Patent: April 6, 1993
    Assignee: Westland Helicopters Ltd.
    Inventors: Frederick J. Perry, Alan Brocklehurst
  • Helicopter rotors
    Patent number: 5100294
    Abstract: A flexible beam type helicopter rotor includes restraining means outboard of a snubber means and connected between the flexible beam and a torque tube to increase the stiffness of the rotor in the lead/lag plane as applied pitch is increased.
    Type: Grant
    Filed: September 24, 1990
    Date of Patent: March 31, 1992
    Assignee: Westland Helicopter Limited
    Inventors: Mark A. Crannage, Robert E. Hansford, Frederick J. Perry
  • Helicopter rotor blades
    Patent number: 4975022
    Abstract: The swept extreme tip edge of a helicopter rotor blade incorporates blade droop to reduce aerodynamic pitching moments caused by spanwise flow encountered in the fore and aft sectors of a rotor rotational disc during forward flight of a helicopter on which the blade is fitted.
    Type: Grant
    Filed: June 27, 1989
    Date of Patent: December 4, 1990
    Assignee: Westland Helicopter Limited
    Inventor: Frederick J. Perry
  • Helicopter rotor blade
    Patent number: 4668169
    Abstract: An outboard region of a helicopter rotor blade of aerofoil cross section has a thickness to chord ratio not greater than twelve percent and an inboard region has a thickness to chord ratio greater than twelve percent. Preferably, the thickness to chord ratio of the inboard region is greater than eighteen percent and may increase towards the root end to about twenty four percent. The inboard region may extend outwardly to a position not exceeding sixty percent of an operating radius of the rotor blade.
    Type: Grant
    Filed: June 19, 1984
    Date of Patent: May 26, 1987
    Assignee: Westland plc
    Inventor: Frederick J. Perry
  • Helicopter rotor blade
    Patent number: 4427344
    Abstract: A helicopter rotor blade is disclosed having a root end for attachment to a rotor head, a tip end defining the end of the blade fartherest from the root end with a central portion of aerofoil section extending between and attached to the root end and the tip end to define a rotor radius wherein an outboard region of the central portion has a negative basic pitching moment coefficient of absolute value not less than 0.02 and an inboard region having a basic pitching moment coefficient more positive than that of the outboard region.
    Type: Grant
    Filed: March 13, 1981
    Date of Patent: January 24, 1984
    Assignee: Westland Aircraft, Ltd.
    Inventor: Frederick J. Perry