Patents/Certificates Archive

Dee had over forty US and foreign patents issued in his name for both aviation and automotive products and the aviation companies which he founded and which bore his name held more than one hundred FAA Supplemental Types Certificates (STCs) and Type Certificate (TC).

Partial listing of TCs and STCs issued to Howard entities

 Aircraft Type Certificate (Download PDF)

Supplemental Type Certificates (Download PDF)

List of U.S. Patents* Issued to Durrell U. (“Dee”) Howard

* Some U.S. Patents were also issued in Belgium, Canada, France, Germany, Mexico and the United Kingdom

Patents/Certificates Files

Steer Wheel Control System with Reciprocating Cylinder

  • Patent No.: 7,806,419
  • Issue Date: October 05, 2010

Steer Wheel Control System With Stationary Piston and Reciprocating Cylinder

  • Patent No.: 7,219,908
  • Issue Date: May 22, 2007

Steer Wheel Control System With Dual Pistons Connected to a Common Shaft

  • Patent No.: 7,118,118
  • Issue Date: October 10, 2006

Steer Wheel Control System With Trimmable Rotary Plate

  • Patent No.: 6,994,361
  • Issue Date: February 07, 2006

Precision Steer Wheel Control System with Internal Solenoid

  • Patent No.: 6,817,620
  • Issue Date: November 16, 2004

Vehicle Steering Stabilizer With Detent Ramp in Rotary Plate

  • Patent No.: 6,530,585
  • Issue Date: March 11, 2003

Trimming Apparatus for Steer Wheel Control Systems

  • Patent No.: 6,520,519
  • Issue Date: February 18, 2003

Steering Stabilizer With Trimming Accumulator

  • Patent No.: 6,520,520
  • Issue Date: February 18, 2003

Center Holding Assembly for Vehicle Steering Systems

  • Patent No.: 6,422,582
  • Issue Date: July 23, 2002

Steering Shaft Centering Assembly

  • Patent No.: 6,272,947
  • Issue Date: August 14, 2001

Vehicle Steering Compensator with Air Actuated Trim Mechanism

  • Patent No.: 6,267,395
  • Issue Date: July 31, 2001

Power Steering System with Controlled Centering

  • Patent No.: 6,065,561
  • Issue Date: May 23, 2000

Rotary Centering Compensator or Vehicle Steering Systems

  • Patent No.: 6,003,887
  • Issue Date: December 21, 1999

Sealed Self-Adjusting Bearing Assembly

  • Patent No.: 5,816,731
  • Issue Date: October 06, 1998

Steering Column Centering Assembly

  • Patent No.: 5,816,594
  • Issue Date: October 06, 1998

External Sliding Aircraft Door

  • Patent No.: 5,673,874
  • Issue Date: October 07, 1997

Power Centering Compensator for Vehicle Steering Systems

  • Patent No.: 5,536,028
  • Issue Date: July 16, 1996

Detent Centering Compensator for Vehicle Steering Systems

  • Patent No.: 5,527,053
  • Issue Date: June 18, 1996

Self-Adjusting Bearing Assembly

  • Patent No.: 5,435,652
  • Issue Date: July 25, 1995

External Sliding Aircraft Door

  • Patent No.: 5,259,576
  • Issue Date: November 09, 1993

Trailer Coupling Means

  • Patent No.: RE 33,012
  • Issue Date: August 08, 1989

Remotely Adjustable Steering Compensator

  • Patent No.: 4,534,577
  • Issue Date: August 13, 1985

Remotely Adjustable Steering Compensator

  • Patent No.: 4,418,931
  • Issue Date: December 06, 1983

Snap-Action Battery Cable Switch

  • Patent No.: 4,410,775
  • Issue Date: October 18, 1983

Remotely Adjustable Compensator for Centering Steering Systems

  • Patent No.: 4,410,193
  • Issue Date: October 18, 1983

Speed Responsive Trailer Stabilizer with Zero Slack

  • Patent No.: 4,313,616
  • Issue Date: February 02, 1982

Battery Cable Switch

  • Patent No.: 4,306,126
  • Issue Date: December 15, 1981

Self-Threading Bobber

  • Patent No.: 4,251,941
  • Issue Date: February 24, 1981

Steering Assembly for Towed Vehicles

  • Patent No.: 4,212,483
  • Issue Date: July 15, 1980

Adjustable Suspension Assembly

  • Patent No.: 4,211,429
  • Issue Date: July 08, 1980

Trailer Coupling Means

  • Patent No.: 3,994,510
  • Issue Date: November 30, 1976

Self-Contained Sanitary Closet for Vehicles or the Like

  • Patent No.: 3,858,249
  • Issue Date: January 07, 1975

Trailer Coupling Means

  • Patent No.: 3,825,281
  • Issue Date: July 23, 1974

Vehicle Flush Toilet

  • Patent No.: RE 27,833-Reissue of 3.418,664
  • Issue Date: December 11, 1973

Sanitary Vehicle Closet

  • Patent No.: 3,611,446
  • Issue Date: October 12, 1971

Vehicle Flush Toilet

  • Patent No.: 3,609,772
  • Issue Date: October 05, 1971

Vehicle Flush Toilet

  • Patent No.: 3,418,664
  • Issue Date: December 31, 1968

Reserve Fuel Supply Systems

  • Patent No.: 3,390,698
  • Issue Date: July 02, 1968

Reserve Fuel Systems

  • Patent No.: 3,326,264
  • Issue Date: June 20, 1967

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