Patents & Certifications

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). The following is a partial listing of each.

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

Tab#  Title Patent No. Issue Date
1 Reserve Fuel Systems 3,326,264 20 June 1967
2 Reserve Fuel Supply Systems 3,390,698 2 July 1968
3 Vehicle Flush Toilet 3,418,664 31 Dec 1968
4 Integral Fuel Tank 3,420,477 7 Jan 1969
5 Aircraft Main Spare Modification 3,542,320 24 Nov 1970
6 Vehicle Flush Toilet 3,609,772 5 Oct 1971
7 Sanitary Vehicle Closet 3,611,446 12 Oct 1971
8 Sanitary Closet 3,611,447 12 Oct 1971
9 Vehicle Flush Toilet RE 27,833-Reissue of 3.418,664 11 Dec 1973
10 Trailer Coupling Means 3,825,281 23 July 1974
11 Self-Contained Sanitary Closet for Vehicles or the Like 3,858,249 7 Jan 1975
12 Apparatus for Monitoring the Condition of a Filter 3,934,543 27 Jan 1976
13 Trailer Coupling Means 3,994,510 30 Nov 1976
14 Adjustable Suspension Assembly 4,211,429 8 July 1980
15 Steering Assembly for Towed Vehicles 4,212,483 15 July 1980
16 Self-Threading Bobber 4,251,941 24 Feb 1981
17 Battery Cable Switch 4,306,126 15 Dec 1981
18 Speed Responsive Trailer Stabilizer with Zero Slack 4,313,616 2 Feb 1982
19 Remotely Adjustable Compensator for Centering Steering    Systems 4,410,193 18 Oct 1983
20 Snap-Action Battery Cable Switch 4,410,775 18 Oct 1983
21 Remotely Adjustable Steering Compensator 4,418,931 6 Dec 1983
22 Remotely Adjustable Steering Compensator 4,534,577 13 Aug 1985
23 Trailer Coupling Means RE 33,012 8 Aug 1989
24 External Sliding Aircraft Door 5,259,576 9 Nov 1993
25 Self-Adjusting Bearing Assembly 5,435,652 25 July 1995
26 Detent Centering Compensator for Vehicle Steering Systems 5,527,053 18 June 1996
27 Power Centering Compensator for Vehicle Steering Systems 5,536,028 16 July 1996
28 External Sliding Aircraft Door 5,673,874 7 Oct 1997
29 Steering Column Centering Assembly 5,816,594 6 Oct 1998
30 Sealed Self-Adjusting Bearing Assembly 5,816,731 6 Oct 1998
31 Rotary Centering Compensator or Vehicle Steering Systems 6,003,887 21 Dec 1999
32 Power Steering System with Controlled Centering 6,065,561 23 May 2000
33 Vehicle Steering Compensator with Air Actuated Trim    Mechanism 6,267,395 31 July 2001
34 Steering Shaft Centering Assembly 6,272,947 14 Aug 2001
35 Center Holding Assembly for Vehicle Steering Systems 6,422,582 23 July 2002
36 Steering Stabilizer With Trimming Accumulator 6,520,520 18 Feb 2003
37 Trimming Apparatus for Steer Wheel Control Systems 6,520,519 18 Feb 2003
38 Vehicle Steering Stabilizer With Detent Ramp in Rotary    Plate 6,530,585 11 March 2003
39 Precision Steer Wheel Control System with Internal    Solenoid 6,817,620 16 Nov 2004
40 Steer Wheel Control System With Trimmable Rotary Plate 6,994,361 7 Feb 2006
41 Steer Wheel Control System With Dual Pistons Connected to    a Common Shaft 7,118,118 10 Oct 2006
42 Precision Steer Wheel Control System With Remote Trim    Valve Assembly 7,207,580 24 April 2007
43 Precision Steer Wheel Control System With External    Solenoid 7,207,579 24 April 2007
44 Steer Wheel Control System With Stationary Piston and    Reciprocating Cylinder 7,219,908 22 May 2007
45 Steer Wheel Control System with Reciprocating Cylinder 7,806,419 5 Oct 2010

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