Trailer skirt panel

• US 20070120397A1
• Filed: 11/29/2005
• Published: 05/31/2007
• Est. Priority Date: 11/29/2005
• Status: Active Grant

• Current Assignee: ZF Composites North America Limited
• Original Assignee: Laydon Composites Limited (Wabco Holdings Incorporated)
• Inventors: Layfield, Brian, Mancina, Joseph, Haws, James, Prokudin, Andriy
• Granted Patent: US 7,578,541 B2
• Time in Patent Office: Days
• US Class Current: 296/180.400
• CPC Class Codes: B62D 35/001 For commercial vehicles or tractor-trailer combinations, e.g. caravans

Abstract

A skirt panel is provided herein for interconnection to another abutted similar skirt panel for attachment beneath a lower, outer longitudinally-extending edge of a trailer including a rear wheel assembly of a tractor-trailer rig, thereby to provide a continuous fairing extending downwardly from the trailer. The skirt panel includes a monolithic, generally-rectangular composite reinforced thermoplastic structure, having vertical lateral side edges configured and arranged for connection to associated vertical lateral side edges of abutting similar skirt panels. This provides a longitudinally-extending fairing for extending contiguously on each side of the trailer, a front face of the thermoplastic structure being provided with a plurality of longitudinally-extending, vertically-spaced-apart arcuate protrusions. The outer face of the thermoplastic panel preferably also is provided with dimples. The reinforcing comprising a panel secured to an inner face of the skirt panel and is provided with laterally-extending means whereby abutting skirt panels are secured to one another; whereby, when said fairing is secured to a lower portion of said trailer, the fairing extends downwardly from the trailer to from 60% to 80% of the distance to the road, so that a portion of any impinging air is directed laterally around the wheels of the rear wheel bogeys to reduce the aerodynamic drag of the trailer and of the wheel assembly.

Claims

1. A skirt panel for interconnection to another similar skirt panel for attachment beneath a lower, outer longitudinally-extending edge of a trailer including a rear wheel assembly of a tractor-trailer rig, thereby to provide a continuous fairing extending downwardly from said trailer, said skirt panel comprising:

a monolithic, generally-rectangular composite reinforced thermoplastic structure, having vertical lateral side edges configured and arranged for connection to associated vertical lateral side edges of abutting similar said skirt panels, thereby to provide a longitudinally-extending fairing for extending contiguously on each side of said trailer, a front face of said thermoplastic structure being provided with a plurality of longitudinally-extending, vertically-spaced-apart arcuate protrusions;

said reinforcing comprising an open lattice panel secured to an inner face of said skirt panel and being provided with laterally-extending means whereby abutting said skirt panels are secured to one another;

whereby, when said fairing is secured to a lower portion of said trailer, said fairing extending downwardly from said trailer to from 60% to 80% of the distance to the road, so that a portion of any impinging air is directed laterally around the wheels of the rear wheel bogeys to reduce the aerodynamic drag of said trailer and of said wheel assembly.

2. The skirt panel of claim 1, wherein an upper edge of said skirt panel includes means for rigidly securing said skirt panel to said trailer.

3. The skirt panel of claim 2, wherein said means for rigidly securing said skirt panel to said trailer comprises snap members.

4. The skirt panel of claim 1, wherein each vertical edge of said skirt panel includes a reinforcing and connecting truss having connection points to enable abutting similar skirt panels to be rigidly connected to one another.

5. The skirt panel of claim 4, wherein said truss is formed of stamped metal.

6. The skirt panel of claim 4, wherein said truss is of an open lattice structure.

7. The skirt panel of claim 5, wherein said stamped metal comprises galvanized steel vertical truss and securement members which are secured to said thermoplastic portion of said skirt panel.

8. The skirt panel of claim 1 wherein two lateral vertical side edges extend inwardly from the rear face thereof, and wherein upper and lower edges thereof are integrally connected to said two inwardly extending lateral edges.

9. The skirt panel of claim 1, including a support strut connected to the interior face at the bottom edge and secured to the interior face adjacent the top edge thereof.

10. The skirt panel of claim 9, wherein said support strut includes an I-beam clamp at the upper edge thereof.

11. The skirt panel of claim 9, wherein the inner face of said strut at the upper edge thereof includes means to connect said strut to the inner face of said skirt panel.

12. The skirt panel of claim 1, wherein said thermoplastic is selected from the group consisting of co-extruded ABS with a cap of a styrene acrylonitrile copolymer which has been impact-modified with acrylic ester rubber, high molecular weight polyethylene, polypropylene and TPO.

13. The skirt panel of claim 1, including a thinner, more flexible synthetic plastic lower panel, said thinner, more flexible synthetic plastic lower panel being attached to the lower edge of said skirt panel, thereby to allow panel flexing over road objects, e.g., curbs, railroad tracks and below grade loading docks.

14. The lower panel of claim 13, wherein said synthetic plastic comprises a thermoplastic elastomer.

15. The lower panel of claim 14, wherein said thermoplastic elastomer comprises flex PVC.

16. The skirt panel of claim 1, which is about 0.187 inches thin.

17. A method of vacuum forming a skirt panel for interconnection to a similar said skirt panel for attachment beneath a lower, outer longitudinally-extending edge of a trailer including a rear wheel assembly of a tractor-trailer rig, thereby to provide a continuous fairing extending downwardly from said trailer, said method comprising:

providing an aluminum mould;

providing a thin sheet of thermoplastic material;

clamping said thin sheet of thermoplastic material in a clamp frame;

introducing said clamped thin sheet of thermoplastic material into a heating oven.;

heating said oven to a temperature greater than the softening temperature of said thermoplastic material;

placing said heated thin sheet of thermoplastic material over said aluminum mould.;

forcing said mould into said hot thin sheet of thermoplastic material until a sealing flange air seal is formed around the outer edge of said mould;

drawing a vacuum from inside said mould, thereby to force said hot sheet of thermoplastic material to form around the contours of said mould.;

reducing the temperature of said hot sheet of thermoplastic material to a suitable temperature below the softening temperature of said thermoplastic material;

opening said clamp frame and removing said moulded formed first intermediate skirt panel from said mould;

trimming off excess material from said formed first intermediate skirt panel and drilling suitable mounting holes therein, thereby to provide a second intermediate skirt panel;

providing a metal reinforcement which is stamped and formed;

securing said stamped and formed metal reinforcement to the interior of said formed skirt panel, thereby to form vertical truss and clamp members on the interior of said formed second intermediate skirt panel, and thereby to form said skirt panel.

18. The method of claim 17, wherein said heating to a suitable temperature, is about 320°

F.

19. A method of vacuum forming a skirt panel for interconnection to a similar said skirt panel for attachment beneath a lower, outer longitudinally-extending edge of a trailer including a rear wheel assembly of a tractor-trailer rig, thereby to provide a continuous fairing extending downwardly from said trailer, said method comprising:

providing a double aluminum mould;

providing two thin sheets of a thermoplastic material;

clamping an associated thin sheet of said thermoplastic material in each of an associated clamp frame;

fixing said two clamp frames in spaced-apart relationship one above the other with minimal clearance therebetween;

introducing said two spaced-apart clamped thin sheets of thermoplastic material into a heating oven;

heating said oven to a temperature greater than the softening temperature of said thermoplastic material;

placing each said heated sheet of thermoplastic material over an associated half of said aluminum mould;

forcing each said mould half into an associated each said hot sheet of thermoplastic material until a sealing flange air seal is formed around the outer edge of each said mould half;

drawing a vacuum from inside each said mould half;

while said hot thin sheet of thermoplastic material is still hot, clamping said two mould halves together;

applying enough pressure to said clamped two mould halves to bond the areas of contact between said two hot thermoplastic materials to form a permanent single hollow skirt panel;

reducing the temperature of said thermoplastic material to a suitable temperature below the softening temperature of said hot thermoplastic material;

opening said two mould halves;

opening said clamps and removing of said moulded first intermediate skirt panel from said mould;

trimming off excess material from said moulded first intermediate skirt panel and drilling suitable mounting holes therein, thereby to provide a second intermediate skirt panel;

providing a metal reinforcement which is stamped and formed;

securing said stamped and formed metal reinforcement to the interior of said formed skirt panel, thereby to form vertical truss and clamp members on the interior of said formed second intermediate skirt panel, and thereby to form said skirt panel.

20. A method of injection moulding a skirt panel for interconnection to a similar said skirt panel for attachment beneath a lower, outer longitudinally-extending edge of a trailer including a rear wheel assembly of a tractor-trailer rig, thereby to provide a continuous fairing extending downwardly from said trailer, said method comprising:

providing at least one high pressure mould;

producing a first component face panel of said skirt panel by injection moulding a thermoplastic material in said at least one high pressure mould;

producing a second component support strut of said skirt panel by injection moulding a thermoplastic material in said at least one high pressure mould;

extruding a third component thermoplastic material track of said skirt panel;

attaching said first component injection moulded face panel and said second component support strut to said extruded material track of said skirt panel, thereby to provide a first intermediate skirt panel;

providing a means to fasten a horizontal edge of said second component support strut to said tractor-trailer rig;

and providing a means to fasten a horizontal edge of said extruded material track to said tractor-trailer rig, thereby to form said skirt panel having both vertical and horizontal support structures.

21. A method of injection moulding a skirt panel for interconnection to a similar said skirt panel for attachment beneath a lower, outer longitudinally-extending edge of a trailer including a rear wheel assembly of a tractor-trailer rig, thereby to provide a continuous fairing extending downwardly from said trailer, said method comprising:

providing a structural web mould;

producing a first component face panel of said skirt panel by injection moulding a thermoplastic material in said structural web mould;

providing a high pressure mould;

producing a second component support strut of said skirt panel by injection moulding a thermoplastic material in said high pressure mould;

extruding a third component thermoplastic material track of said skirt panel;

attaching said first component injection moulded face panel and said second component support strut to said extruded material track of said skirt panel, thereby to provide a first intermediate skirt panel;

providing a means to fasten a horizontal edge of said second component support strut to said tractor-trailer rig;

and providing a means to fasten a horizontal edge of said extruded material track to said tractor-trailer rig, thereby to form said skirt panel having both vertical and horizontal support structures.

22. The method of claim 21 including the additional steps of:

extruding a thin synthetic plastic panel; and

attaching said extruded synthetic plastic panel to the lower edge of said skirt panel, thereby to provide a final skirt panel, which allows panel flexing over road objects and to achieve further fuel savings.

23. The method of claim 22, wherein said moulds contain inner copper cooling and heating lines, which aid in the manufacturing method.

24. The method of claim 23, wherein said moulds contain an insert, which can be removed to form a side marker light panel.

25. The method of claim 24, wherein said panels are vertically attached to each other by a snap-in feature, without the use of independent fasteners.

26. The method of claim 24, wherein said panels are moulded with “

live hinge”

areas and “

V”

notched rib structure to allow additional panel flexing.

27. The method of claim 21, wherein said thermoplastic is selected from the group consisting of co-extruded ABS with a cap of a styrene acrylonitrile copolymer which has been impact-modified with acrylic ester rubber, high molecular weight polyethylene, polypropylene and TPO.

28. The method of claim 27, wherein said heating to a suitable temperature, is about 320?F.

29. The method of claim 28, wherein said cooling is down to a temperature of about 140?F.

30. The method of claim 22, wherein said extruded synthetic polymer is flex PVC (polyvinyl chloride).

31. The method of claim 30, wherein said thermoplastic elastomer is a thermoplastic elastomer, which can be processed and recycled like thermoplastic materials.

32. A trailer of a tractor-trailer rig to which is fastened a fairing consisting of a plurality of contiguous skirt panels depending below the right hand and left hand sides thereof, to from 60% to 80% of the distance to the road, so that a portion of any impinging air is directed laterally around the wheels of the rear wheel bogeys to reduce the aerodynamic drag of said trailer and of said wheel assembly, said skirt panels having the structure of claim.

33. The trailer of claim 32, wherein said fairing terminates about 10 inches from the surface of the road.