Frame extension device for reducing the aerodynamic drag of ground vehicles

• US 20090256386A1
• Filed: 04/16/2009
• Published: 10/15/2009
• Est. Priority Date: 01/30/2006
• Status: Active Grant

• Current Assignee: Richard M. Wood
• Original Assignee: Richard M. Wood
• Inventors: Wood, Richard M.
• Granted Patent: US 8,007,030 B2
• Time in Patent Office: Days
• US Class Current: 296/180.100
• CPC Class Codes: B62D 35/001 For commercial vehicles or tractor-trailer combinations, e.g. caravans

Abstract

A frame extension device for the reduction of aerodynamic drag and for improved performance of bluff base ground vehicles by increasing the pressure on the base of the vehicle by stabilizing the wake flow. The device is particularly suited for tractor-trailers utilizing a roll-up type rear door in that it does not block any part of the door opening. The device may be of sufficient thickness to support the weight of an unloading device.

Claims

1. An aerodynamic frame extension device for reducing the aerodynamic drag when attached to a rear frame of a bluff base vehicle, the aft surface of the rear frame having a perimeter with a top, bottom and two sides, the device comprising:

a frame extension structure comprised of four panels integrally connected to each other, the frame extension structure being substantially permanently affixed to the perimeter of the aft surface of the rear frame, with a panel extending aft from each of the top, bottom, and two sides;

wherein the frame extension structure has a vertical height equal to at least the vertical height of the rear frame and a width equal to at least the width of the rear frame; and

wherein the panel nearest the bottom of the rear frame has sufficient thickness to support a device for loading and unloading the vehicle and the remaining panels have a thickness of at least 1% of the width of the vehicle.

2. The frame extension device of claim 1, wherein the panels on the top and bottom are substantially orthogonal to the panels on the two sides.

3. The frame extension device of claim 1, wherein the rear frame perimeter, with a top, bottom and two sides, defines a door opening, and further wherein the panels extend aft from each of the top, bottom, and two sides without interfering with the door opening.

4. The frame extension device of claim 1, wherein the panels are formed of a rigid material.

5. The frame extension device of claim 1, wherein the panels are formed of a rigid material selected from metal, wood, plastic, composite, rubber, and ceramic material.

6. The frame extension device of claim 1, wherein the panel nearest the bottom of the door frame is formed of metal.

7. The frame extension device of claim 1, wherein the panels are inset from the outer edge of the rear frame.

8. The frame extension device of claim 1, wherein the device is inset at least one inch from the outer edge of the door frame.

9. The frame extension device of claim 1, wherein the panels are inset from the outer edge of the rear frame a distance of about 0-10% of the vehicle'"'"'s width.

10. The frame extension device of claim 1, wherein the panels are inset from the outer edge of the rear frame a distance of about 0-5% of the vehicle'"'"'s width.

11. The frame extension device of claim 1, wherein the length of the device is about 6 to about 60 inches.

12. The frame extension device of claim 1, wherein the panels are rigid and are joined together into a single piece frame structure.