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