# Patent

## Title
Aerodynamic rear drag reduction system for a trailer

## Abstract

A rear aerodynamic drag reduction system is configured to be coupled to a rear frame assembly of a trailer including a rear frame and a rear swing door. The rear drag reduction system includes a main wall panel configured to be coupled to the rear frame assembly to extend generally rearwardly of the trailer at least partially along a height of the trailer, and a secondary wall panel configured to be movably coupled to the rear swing door of the trailer to extend along a width of the trailer. The main wall panel and the secondary wall panel are each movable relative to the rear frame assembly between a deployed position and a stowed position. A locking mechanism of the drag reduction system is configured to releasably couple the main wall panel and the secondary wall panel to each other to prevent relative movement between the main wall panel and the secondary wall panel when the main and secondary wall panels are in their deployed positions.

## Background
This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/993,306 entitled AERODYNAMIC REAR DRAG REDUCTION SYSTEM FOR A TRAILER and filed May 15, 2014, the entirety of which is hereby incorporated by reference herein.


This application cross-references U.S. patent application Ser. No. 14/049,506 entitled AERODYNAMIC REAR DRAG REDUCTION SYSTEM FOR A TRAILER and filed Oct. 9, 2013, the entirety of which is hereby incorporated by reference herein.
FIELD OF THE INVENTION
The present invention relates generally to semi-trailers, such as van-type trailers, for example. In particular, the present invention relates to an aerodynamic rear tail system for reducing draft on such a trailer.
BACKGROUND OF THE INVENTION
To reduce wind flow resistance and drag on a trailer, truck, semitrailer, or other vehicle, side skirts which extend downwardly from a bottom of the trailer and/or chassis toward the roadway to partially enclose the floor assembly and undercarriage of the trailer, fairings and other such structures have been used. Many structures associated with the rear of the trailer are provided in order to reduce the aerodynamic drag on the trailer.
A typical storage container of a trailer terminates with a large, rectangular rear surface. This shape causes an area of reduced pressure to be created behind the trailer storage container as it moves over the highway, thus generating a slowing force that must be overcome with additional engine power and thus additional fuel. In other words, air flow passing behind the vehicle imparts a drag force to the vehicle. Rear trailer fairings are designed to streamline the rear end of the trailer in order to control the flow of air at the rear of the vehicle. Such reduction on the drag of the ground vehicle may operate to conserve fossil fuels as well as other sources of vehicle drive power for hybrid vehicles, battery-operated vehicles, and alternative fuel-based vehicles, for example. However, many such fairings which cover the rear end of the trailer also may cover the rear doors of the trailer which must be opened and closed by a user to load and unload the cargo within the storage area of the trailer in such a way that users may be required to dismount and mount the fairing(s) each time a loading or unloading operation is to be performed.
SUMMARY
The present invention may comprise one or more of the features recited in the attached claims, and/or one or more of the following features and combinations thereof.
According to one aspect of the present disclosure, a rear aerodynamic drag reduction system configured to be coupled to a rear frame assembly of a trailer including a rear frame and a rear swing door includes a main wall panel, a secondary wall panel, and a locking mechanism. The main wall panel is configured to be coupled to the rear frame assembly to extend generally rearwardly of the trailer at least partially along a height of the trailer. The main wall panel is movable relative to the rear frame assembly between a deployed position and a stowed position. The secondary wall panel is configured to be movably coupled to the rear swing door of the trailer to extend generally rearwardly of the trailer at least partially along a width of the trailer. The secondary wall panel is movable relative to the rear frame assembly between a deployed position and a stowed position. The locking mechanism is configured to releasably couple the main wall panel and the secondary wall panel to each other to prevent relative movement between the main wall panel and the secondary wall panel when the main and secondary wall panels are in their deployed positions.
In one illustrative embodiment, the main wall panel and the secondary wall panel may each be configured to be pivotably coupled to the rear frame assembly. The secondary wall panel may be pivotably coupled to the rear swing door of the rear frame assembly. Illustratively, the main wall panel may be configured to be pivotably coupled to the rear swing door of the rear frame assembly, and the main wall panel may be configured to pivot about an axis offset from an axis about which the rear swing door pivots. Alternatively, the main wall panel may be configured to be pivotably coupled to a vertical member of the rear fame of the rear frame assembly, and the main wall panel may be configured to pivot about an axis aligned with an axis about which the rear swing door pivots.
In another illustrative embodiment, the locking mechanism may include a first portion coupled to the main wall panel and a second portion coupled to the secondary wall panel. The first and second portions of the locking mechanism may be configured to releasably engage each other.
In still another illustrative embodiment, the locking mechanism may include (i) a latch coupled to the one of the main wall panel and the secondary wall panel, the latch defining a slot, and (ii) a pin coupled to the other of the main wall panel and the secondary wall panel. Illustratively, the pin may be received within the slot when the main and secondary wall panels are in their deployed positions. Further illustratively, the latch may be coupled to an inner surface of the secondary wall panel and the pin is coupled to an inner surface of the main wall panel. The latch may be positioned adjacent outer and bottom edges of the secondary wall panel and the pin may be positioned adjacent the rear and top edges of the main wall panel. Illustratively, the pin may include a head received within the slot when the main and secondary wall panels are in their deployed positions, and a body coupled to the inner surface of the main wall panel. Further illustratively, the body of the pin may include an upper portion offset from a lower portion. The latch may be integrally formed with the secondary wall panel and the pin may be integrally formed with the main wall panel. As such, the latch may illustratively extend downwardly below an inner surface of the secondary wall panel and the pin may extend upwardly above a top edge of the main wall panel.
In yet another illustrative embodiment, the locking mechanism may be automatically moved to a locked position when a user moves the rear swing door to a fully-closed position. Further, the locking mechanism may be automatically moved to an unlocked position when a user moves the rear swing door to a fully-opened position. Illustratively, the main wall panel may also be automatically moved to the deployed position when a user moves the rear swing door to a fully-closed position, and the main wall panel may be automatically moved to the stowed position when a user moves the rear swing door to a fully-opened position.
According to another aspect of the present disclosure, a rear aerodynamic drag reduction system configured to be coupled to a rear frame assembly of a trailer including a rear frame and a rear swing door includes a main wall panel configured to be coupled to a vertical member of the rear frame to extend generally rearwardly of the trailer at least partially along a height of the trailer, a secondary wall panel configured to be coupled to the rear swing door of the trailer to extend generally rearwardly of the trailer at least partially along a width of the trailer, and a locking mechanism having a first portion coupled directly to the main wall panel and a second portion coupled directly to the secondary wall panel. The first and second portions of the locking mechanism are coupled to each other when the main wall panel and the secondary wall panel are configured to extend rearwardly of the trailer.
In one illustrative embodiment, the main wall panel may be movable between a deployed position and a stowed position. Illustratively, the secondary wall panel may also be movable between a deployed position and a stowed position. Further illustratively, the main wall panel may be automatically moved to the deployed position and the locking mechanism may be automatically moved to a locked position when a user moves the rear swing door to a fully-closed position. Illustratively, the first and second portions of the locking mechanism may be automatically engaged with each other as the main and secondary wall panels are moved to the deployed position. Further, the first and second portions of the locking mechanism may be automatically disengaged with each other as the main and secondary wall panels are moved to the stowed position.
In another illustrative embodiment, the secondary wall panel may include a first portion configured to be coupled to a top of the rear swing door and a second portion pivotably coupled to the first portion for movement about an axis parallel to a top edge of the rear swing door.
Illustratively, the second portion of the locking mechanism may be coupled to the second portion of the secondary wall panel. Further illustratively, the second portion of the secondary wall panel may be configured to engage a top edge of the main wall panel when the main wall panel is in the deployed position. An inner surface of the second portion of the secondary wall panel may be configured to engage and lie adjacent to an outer surface of the main wall panel when the main wall panel is in the stowed position.
According to yet another aspect of the present disclosure, a rear aerodynamic drag reduction system configured to be coupled to a rear frame assembly of a trailer including a rear frame and a rear swing door includes a main wall panel configured to be pivotably coupled to a vertical member of the rear frame to extend generally rearwardly of the trailer at least partially along a height of the trailer, a secondary wall panel configured to be pivotably coupled to the rear swing door of the trailer to extend generally rearwardly of the trailer at least partially along a width of the trailer, a locking mechanism configured to releasably lock the main wall panel and the secondary wall panel to each other. The locking mechanism includes (i) a first portion coupled directly to the main wall panel to extend above the main wall panel and (ii) a second portion coupled directly to an inside surface of the secondary wall panel. Illustratively, the main wall panel and the secondary wall panel are movable relative to the rear frame assembly between deployed positions and stowed positions. Further, the first portion of the locking mechanism is automatically received within a slot of the second portion of the locking mechanism when the main wall panel and the secondary wall panel are moved to their deployed positions.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a rear end portion of a trailer showing a drag reduction system of the present disclosure including a rear fairing structure coupled to a rear frame of the trailer and shown in the fully-deployed position when the rear doors of the trailer are fully-closed.
FIG. 2 is a perspective view similar to FIG. 1 showing the doors of the trailer partially opened such that the rear fairing structure is only partially deployed as it moves toward a fully-closed, or retracted, position.
FIG. 3. is a perspective view similar to FIGS. 1 and 2 showing the doors in an opened position (with one door removed in order to better view the rear fairing structure) and showing the rear fairing structure retracted and positioned adjacent an outer surface of the door.
FIG. 4. is a perspective view similar to FIGS. 1-3 showing the doors of the trailer in a fully-opened position adjacent the sidewalls of the trailer and showing the rear fairing structure in the retracted position between the doors and the sidewalls of the trailer.
FIG. 5. is a perspective view of a portion of the drag reduction system of the present disclosure including a locking mechanism to maintain the rear fairing structure in a fully deployed position.
FIG. 6 is a schematic view of an alternative locking mechanism of the rear drag reduction system.
FIG. 7 is a rear perspective view of a portion of an alternative drag reduction system showing an alternative hinge coupling the main wall member to the rear swing door of the trailer to define a pivot axis of the main wall member that is offset from a pivot axis of the rear swing door.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to illustrative embodiments shown in the attached drawings and specific language will be used to describe the same. While the concepts of this disclosure are described in relation to a truck trailer, it will be understood that they are equally applicable to other vehicles generally, and more specifically to conventional flat-bed and/or box or van type trailers, examples of which include, but should not be limited to, straight truck bodies, small personal and/or commercial trailers and the like. Accordingly, those skilled in the art will appreciate that the present invention may be implemented in a number of different applications and embodiments and is not specifically limited in its application to the particular embodiments depicted herein.
Looking first to FIG. 1, a trailer 10 includes an aerodynamic rear drag reduction system 12 coupled to the rear frame assembly (including a rear frame 13 and rear doors 14 coupled to the rear frame 13) of the trailer 10. Illustratively, the drag reduction system 12 operates to improve the aerodynamic efficiency of the trailer 10 by reducing drag and wind flow behind the rear end of the trailer 10. In particular, the drag reduction system 12 operates to reduce airflow immediately behind the trailer 10 as the trailer 10 is traveling down the road. As is discussed in greater detail below, the airflow immediately behind the rear end of the trailer 10 is reduced because the drag reduction system 12 channels and controls the flow of air from the sides and top of the trailer 10 over the rear end of the trailer 10. This reduction of airflow behind the trailer 10 may increase the fuel efficiency, or the efficiency of any other source of vehicle drive power, of the tractor/trailer combination.
Illustratively, the drag reduction system 12 extends behind the rear frame 13 and rear doors 14 of the trailer 10. As is further discussed in additional detail below, the drag reduction system 12 is movable with the rear doors 14 of the trailer 10 between a fully-deployed, or use, position, and a fully-closed, or storage position. As shown in FIGS. 1 and 2, the trailer 10 includes a storage container 15 configured to carry cargo therein. The storage container 15 includes sidewalls 11, a front end wall (not shown), the rear end frame assembly (including the rear frame 13 and doors 14), a roof 22, and a floor assembly 24 which all cooperate together to define an inside storage portion 25 of the container 15 that is able to store various articles or goods therein. The trailer 10 further includes a rear wheel assembly, or bogie, 16, and a front support or landing gear (not shown) each coupled to the floor assembly 24 of the trailer 10. Illustratively, the floor assembly 24 of the trailer 10 includes various laterally-extending cross members (not shown) as well as longitudinally-extending floor boards 26. The front end of the trailer 10 is configured to be coupled to a tractor (not shown) for towing the trailer 10 thereon, thus providing a tractor-trailer assembly. It should be understood that while the aerodynamic drag reduction system 12 is shown for use with a trailer 10, the drag reduction system 12 may be coupled to any vehicle to reduce the drag thereon.
Illustratively, the trailer 10 includes two drag reduction systems 12, as shown in FIG. 1. In particular, one system 12 is coupled to one rear swing door 14 of the trailer 10, while the other system 12 is coupled to the other rear swing door 14 of the trailer 10. For the purposes of the description herein, however, only one drag reduction system 12 will be described herein. However, it should be understood that the two drag reduction systems 12 of the trailer 10 are identical in configuration and function.
As shown in FIGS. 1 and 2, the drag reduction system 12 includes a main wall panel 30 and a secondary wall panel 32. As shown in FIG. 1 and discussed in greater detail below, the main wall panel 30 is generally vertically-oriented and is hingedly coupled to a vertical member 27 of the rear frame assembly 13 of the trailer 10. The auxiliary wall panel 32 is adjacent the main wall panel 30 and is hingedly coupled to a top end of the swing door 14.
As shown in FIG. 1, the left main wall panel 30 of the first drag reduction system 12 is coupled to the left-most vertical member 27 of the rear frame 13 of the trailer 10 while the right main wall panel 30 of the second drag reduction system 12 is coupled to the right-most vertical member 27 of the rear frame 13 of the trailer 10. Illustratively, four hinges 29 are provided to pivotably couple the main wall panel 30 to the rear frame 13. However, it should be understood that any suitable number of hinges may be used as well. Further, the hinge 29 may be any suitable hinge to allow for pivotable movement of the main and secondary wall panels 30, 32 such as, but not limited to, a butt hinge, a butterfly hinge, a living hinge, etc., in order to allow the main wall panel 30 and the auxiliary wall panel 32 to hingedly move relative to the rear frame assembly 13 of the trailer 30 along with a pivot axis 53 defined by the hinges.
Illustratively, the pivot axis 53 of the main wall panel 30 is aligned with the pivot axis of the rear swing door 14. As shown in FIG. 1, for example, the rear swing door 14 is coupled to the rear frame 13 of the trailer 10 by hinges 28. Hinges 29 of the main wall panel 30 are positioned above and aligned with the hinges 28 for the rear swing door 14 such that the rear swing door 14 and the illustrative main wall panel 30 are configured to pivot about the same pivot axis 53. As is described in detail below, however, the main wall panel 30 may be coupled directly to the swing door 14 so that the main wall panel 30 pivots about an axis that is offset from the pivot axis 53 of the rear swing door 14. In other words, it should be understood that the pivot axis about which the main wall panel 30 pivots may be the same as or different from the pivot axis about which the rear swing door 14 pivots.
As shown in FIG. 3, the main wall panel 30 includes a generally rectangular body 34 defined by a top edge 36, a bottom edge 38, an inside edge 40, and an outside edge 42. Illustratively, the inside and d outside edges 40, 42 are parallel to each other and to the vertical post 27 of the rear frame assembly 13. The bottom edge 38 generally extends horizontally and is perpendicular to the inside and outside edges 40, 42. As showing in FIG. 3, the outside edge 42 include a notice 44 formed therein. As is discussed in greater detail below, the notice 44 operates to provide an opening for the door locking mechanisms and/or handles (now shown) of the rear door 14 to allow the panel 30 to be able to lie generally flat against an outer surface of the rear door 14 when in the closed, or retracted, position. The top edge 36, however, is not parallel to the bottom edge 38 and is not perpendicular to the inside and outside edges 40, 42. Rather, the top edge 36 us angled relative to the outer edges 38, 40, 42. Particularly, the top edge 36 is angled downwardly from the outside edge 40 to the inside edge 42. It should be understood that while the top edge 36 is shown to be angled downwardly, it is within the scope of this disclosure for the top edge 36 to be generally horizontal or angled upwardly as well. Further, it is within the scope of this disclosure to include a body 34 of the main wall panel 30 defining inside and outside edges which are not parallel to each other or to the vertical post 27 of the rear frame 13 to which the main wall panel 30 is attached. As is discussed in greater detail below, the top edge 36 of the panel 30 operates to support the secondary wall panel 32 therefrom when the drag reduction system 12 is in the use position as shown, for example, in FIG. 1.
Illustratively, the body 34 of the main wall panel 30 extends below a bottom edge 50 of the rear sill 52 of the rear frame 13 of the trailer 10 such that the bottom edge 38 of the main wall panel 30 is positioned below the bottom edge 50 of the rear frame 13, as shown in FIGS. 1-4. As such, an overall length of the outside edge 40 of the main wall panel 30 is longer than an overall length of the rear frame 13 of the trailer 10. Further, an overall length of the outside edge 40 of the main wall panel 30 is greater than a height of the sidewall 11 of the storage container 15 of the trailer 10. While the illustrative main wall panel 30 extends below the rear frame 13, it should be understood that it is within the scope of this disclosure to include a main wall panel 30 having any suitable length including one which does not extend below the rear frame 13 of the trailer 10 and/or one which is generally equivalent in length to the rear frame 13 of the trailer 10.
As shown in FIGS. 1 and 2, the secondary wall panel 32 is coupled to a top portion of the rear swing door 14 and is configured to pivot about an axis 54 relative to the swing door 14. Illustratively, the secondary wall panel 32 includes a first portion 60 and a second portion 62 hingedly coupled to the first portion 60. The first portion 60 is coupled to the top portion of the swing door 14 and is configured to extend above a top edge 66 of the swing door 14. Illustratively, the first portion 60 extends generally upwardly to define a planar surface generally parallel to the outer surface of the swing door 14. The second portion 62 of the secondary wall panel 32 is coupled to the first portion 60 via a hinged connection. As shown in FIGS. 1 and 2, and as is discussed in greater detail below, the second portion 62 is configured to extend outwardly away from the first portion 60 and away from the swing door 14, as shown in FIG. 1 when the drag reduction system 12 is in the fully-deployed, or use, position. The second portion 62 is also configured to lie generally adjacent the first portion 60 such that the outer surface of the second portion 62 is generally parallel to the first portion 60, as shown for example in FIG. 3, when the drag reduction system 12 is in the stowed position.
Illustratively, the second portion 62 defines first and second outer edges 70, 72, a top edge 74, and a bottom edge 76. As shown in FIG. 2, the side edges 70, 72 converge toward each other from the top edge 74 toward the bottom edge 76. Thus, a length of the bottom ledge 76 is smaller than a length of the top edge 74.
The drag reduction system 12 further includes an inner limit strap 80, shown in FIGS. 1 and 2. The inner limit strap 80 includes a first end 82 coupled to an inner surface 83 of the main wall member 30 and a second end 84 coupled to the outer surface 85 of the swing door 14. As is described in greater detail below, the inner limit strap 80 operates to limit the movement of the main wall panel 30 relative to the swing door 14. In addition to the inner limit strap 80, the drag reduction system 12 further includes an outer limit strap 90 having a first end 92 coupled to an outer surface 93 of the main wall panel 30 and a second end 94 coupled to the outer, vertical post 27 of the rear frame 13 of the trailer 10, as shown in FIGS. 1 and 2. As is discussed in greater detail below, the outer limit strap 90 also operates to limit movement of the main wall panel 30 relative to the swing door 14. In particular, the inner limit strap 80 operates to prevent outward swinging movement of the main wall panel 30 relative to the swing door 14 beyond a predetermined angle while the outer limit strap 90 operates to prevent inward swinging movement of the main wall panel 30 relative to the swing door 14 beyond a predetermined angle. The length of the limit straps 80, 90 may be made variable in order to selectively change the predetermined angle beyond which the door 14 is unable to swing (both outwardly and inwardly).
In use, as noted above, the drag reduction system 12 operates to increase aerodynamic efficiencies of the trailer 10 to which it is attached by smoothing the airflow behind the rear frame 13 of the trailer 10 as the trailer 10 travels along a highway, for example. Illustratively, the drag reduction system 12 is movable between a fully-deployed position, as shown in FIG. 1, and a retracted, or closed, position, as shown in FIGS. 3 and 4. In the fully-deployed position, the drag reduction system 12 is operable to reduce the drag of the trailer 10 as the trailer 10 travels along a highway, for example. As shown in FIG. 1, the main wall panel 30 extends outwardly away from the rear frame 13 of the trailer 10. Illustratively, the plane defined by the main wall panel 30 is neither parallel to nor perpendicular to a plane defined by the sidewall 11 of the trailer 10. The main wall panel 30 is similarly neither parallel to nor perpendicular to a plane defined by the rear frame 13. In other words, the main wall panel 30 is angled relative to the sidewall 11 of the trailer 10 and is angled relative to the rear frame 13 of the trailer 10. While the main wall panel 30 of the drag reduction system 12 is illustratively shown to be angled relative to the rear frame 13 by a particular degree, it should be understood, that it is within the scope of this disclosure to angle the main wall panel 30 relative to the rear frame 13 by any suitable degree.
In the fully-deployed position, the inner limit strap 80 and the outer limit strap 90 cooperate to maintain the main wall panel 30 in the deployed position. As noted above, the inner limit strap 80 operates to prevent the main wall panel 30 from pivoting outwardly about the axis 53 relative to the rear frame 13 beyond a certain predetermined position while the outer limit strap 90 operates to prevent the main wall panel 30 from pivoting inwardly about the axis 53 relative to the rear frame 13 beyond a certain predetermined position. Illustratively, the inner and outer limit straps 80, 90 may be made from any suitable, flexible or bendable, but generally non-elastic material. Further, while only one inner strap 80 and one outer strap 90 are shown, it is within the scope of this disclosure to include any number of inner and/or outer straps for maintaining the deployed position of the main wall panel 30. Further, it is within the scope of this disclosure for the drag reduction system 12 to include devices other than the inner and outer straps 80, 90 for maintaining the deployed position of the main wall panel 30. In other words, other stops or limiters may be coupled to the main wall panel 30 in order to prevent outward movement of the main wall panel 30 relative to the swing door 14 of the trailer 10 beyond a certain predetermined position and to prevent inward movement of the main wall panel 30 relative to the rear frame 13 and the rear swing door 14 beyond a certain predetermined position.
Looking still to FIG. 1, the secondary panel 32 of the drag reduction system 12 extends outwardly from the rear swing door 14 of the trailer 10 when the system 12 is in the deployed position. Illustratively, an inner surface of the secondary panel 32 rests upon the top edge 36 of the main wall panel 30 when in the deployed position. As noted above, the top edge 36 of the main wall panel 30 is angled downwardly. As such, the secondary panel 32 is angled slightly downwardly as well. In other words, a plane defined by the second portion 62 of the secondary panel 32 is not parallel to a top surface of the roof assembly 22 of the trailer 10. Rather, the second portion 62 is angled downwardly.
When the drag reduction system 12 is in the deployed position, the swing doors 14 of the trailer 10 are closed. The main and secondary wall panels 30, 32 of each of the two drag reduction systems 12 extend outwardly from the rear frame 13 and rear swing doors 14 in order to direct and smooth air flow around the rear end of the trailer 10 as the trailer 10 travels down the highway, for example. The inner and outer limit straps 80, 90 maintain the position of the main wall panels 30 of each drag reduction system 12 while the second portion 62 of the secondary panel 32 rests upon the top edge 36 of the main wall panel 30 of each respective system 12.
When the trailer 10 is not traveling on the road and it is necessary for a user or operator to open the rear doors 14 of the trailer 10 in order to gain access to the storage area 25 of the storage container 15, the user need only open the doors 14 in the usual or typical manner and the drag reduction system 12 coupled to each door 14 automatically moves to its closed position, as shown in FIGS. 2-4. Looking to FIG. 2, as the swing door 14 is opened, the swing door 14 is moved toward the main wall panel 30 while the main wall panel 30 remains generally stationary relative to the trailer 10. As the swing door 14 is moved closer to the main wall panel 30, the bottom surface of the second portion 62 of the secondary panel 32 remains engaged with the top surface 36 of the main wall panel 30. Once the outer surface 85 of the swing door 14 engages the inner surface of the main wall panel 30, the top edge 36 of the main wall panel 30 no longer supports the second portion 62 of the secondary panel 32. Thus, the second portion 62 of the secondary panel 32 pivots downwardly about the axis 54 such that the bottom surface of the second portion 62 of the secondary panel 32 is engaged with the outer surface of the main wall panel 30. During movement of the swing door 14 toward the main wall panel 30, the inner limit strap 80 collapses such that there is not tension on the inner limit strap 80, as shown in FIG. 2. Looking to FIG. 4, once the door 14 is moved to the fully-opened position, the drag reduction system 12 is in the closed, or retracted, position and is located between the outside surface of the swing door 14 and the sidewall 11 of the trailer 10. The outside surface of the main wall panel 30 and the outside surface of the second portion 62 of the secondary panel 32 are each engaged with the sidewall 11 of the trailer 10. The inner surface of the main wall panel 30 is engaged with the outer surface 85 of the swing door 14.
In order to move the drag reduction systems 12 to the opened, or deployed, position, the user or operator need only move the doors 14 of the trailer 10 from their fully-opened position back to their fully-closed position, shown in FIG. 1. In use, therefore, as the doors 14 are closed, the drag reduction system 12 associated with each door 14 is automatically moved to the deployed position. In particular, as the swing door 14 is moved from the fully-opened position shown in FIG. 4 toward the closed position shown in FIG. 1, the drag reduction system 12 associated therewith moves with the door 14. As noted above, the secondary wall panel 32 is coupled to the door 14 for movement therewith. Further, when the drag reduction system 12 is in the fully-closed position (and the door 14 is in an opened position), the secondary wall panel 32 is positioned over the main wall panel 30 such that the secondary wall panel 32 moves with the door 14 as the door 14 is moved from the opened position to the closed position. As such, the main wall panel 30 is also urged to move with the door 14 because the secondary panel 32 covers the main panel 30 and carries it therewith.
As the door 14 is further moved toward the closed position and once the main wall panel 30 reaches the predetermined deployed position, the outer limit strap 90 prevents further movement of the main wall panel 30 with the door 14. As the door 14 is further moved toward the closed position, the main wall panel 30 remains generally stationary and the second portion 62 of the secondary wall panel 32 begins to pivot upwardly about the pivot axis 54. The second portion 62 is urged to pivot upwardly because as the secondary wall panel 32 continues to move with the door 14 as the door 14 moves to the closed position, the bottom surface of the second portion 62 of the secondary wall panel 32 remains supported by the top edge 36 of the main wall panel 30 and moves along this top edge 36 of the main wall panel 30 while the main wall panel 30 remains relatively stationary. As such, the second portion 62 of the secondary wall panel 32 is moved upwardly to the deployed position shown in FIG. 1.
In other words, it is not necessary to perform an extra step to move the drag reduction system 12 to the closed position prior to opening the trailer doors 14 or to move the drag reduction system 12 to the opened position after closing the door 14. Rather, the drag reduction system 12 automatically moves to the closed position upon opening the door 14 to which the drag reduction system 12 is attached and moving the door 14 to the fully opened position along the sidewall 11 of the trailer 10, as shown in FIG. 4. It should be understood that the drag reduction systems 12 of the present disclosure may be used alone or in conjunction with other drag reduction systems such as, for example, aerodynamic side skirts such as those disclosed in U.S. Pat. Nos. 8,177,286 and 8,783,758, for example, the entirety of each of which is incorporated herein by reference.
Illustratively, each wall panel 30, 32 is made of a composite material. For example, the composite material may include a plastic core and metal outer skins coupled to the plastic core. Such a composite material provides a rigid, but lightweight and durable material. Illustratively, for example, each wall panel 30, 32 may be made of a DURAPLATE® composite panel provided by Wabash National Corporation of Lafayette, Ind. DURAPLATE® composite panels are constructed of a high-density polyethylene plastic core bonded between two high-strength steel skins.
The inner and outer skins respectively may be formed of a metal or metallic composition, examples of which include, but should not be limited to aluminum, galvanized steel, full hardened steel, such as AISI Grade E steel, or the like. In one illustrative embodiment, for example, the outer skin is formed of ASTM G90 galvanized steel, and the inner skin is formed of ASTM G40 galvanized steel. In alternative embodiments, the inner and/or outer skins respective may be formed of other rigid, semi-rigid, metallic or non-metallic materials. Illustratively, the composite material (i.e., panels 30, 32) is approximately between 0.08 inch and 0.20 inch thick, with a preferred thickness of approximately 0.10 inch thick. While the illustrative panels 30, 32 disclosed herein are each made of the particular composite material described above, it should be understood that other suitable composite materials may be used as well. For example, the panels 30, 32 may also be made from a plastic pultrusion with fiber reinforcements embedded inside the polymer material. The reinforcement fibers may be made from glass, carbon, and/or other suitable materials, for example.
It should be further understood that while the illustrative panels 30, 32 disclosed herein are made from a composite, the panels 30, 32 may alternatively be formed from a non-composite material such as a sheet made from a metal, metal alloy, or plastic, for example. The panels 30, 32 may be made from ferrous or nonferrous materials including plastics or composites incorporating a combination of ferrous and/or nonferrous materials therein. In particular, an alternative panel (not shown) may be made from galvanized steel. Of course, it is within the scope of this disclosure to include non-galvanized steel sheets, or other such non-composite panels, of any suitable thickness as well.
Looking now to FIG. 5, the rear drag reduction system 12 includes a locking mechanism 100. The locking mechanism 100 includes a grooved latch (or second portion) 102 coupled to an inner, or bottom, surface 104 of the secondary panel 32 and a pin (or first portion) 106 coupled to an inner surface 108 of the main wall panel 30. The pin 106 is coupled near the top edge 36 of the main wall panel 30 near the rear, or trailing, edge 42 of the main wall panel 30. The pin 106 includes a boss, or head, 110 having a diameter larger than a body 112 of the pin 106. Illustratively, the body 112 of the pin 106 is angled and a bottom portion of the body 112 is coupled to the wall panel 30 by fasteners such as screws 114, for example. The grooved latch 102 includes a slot, or groove, 116 configured to receive the head 110 of the pin 106 therein in order to limit the main panel 30 vertically and in one direction laterally. The grooved latch 102 is similarly coupled to the secondary panel 32 by fasteners such as screws 114 for example. Other fasteners such as nails, bolts, and/or adhesives, for example, may be used as well. When the rear drag reduction system 12 is moved to the fully-opened position, the head 110 of the pin 106 is received within the groove 116 of the latch 102 to maintain the relative position of the panels 30, 32 to each other. As the rear drag reduction system 12 is moved to the fully-closed position, the pin 106 is automatically moved out of the groove 16 as the swing doors 85 of the trailer 10 are opened in order to allow the panel 32 to fold over the panel 30.
Looking now to FIG. 6, an alternative locking mechanism 200 is provided wherein the secondary panel 32 includes an outer edge feature, such as the latch or hook, 202 which may be integrally molded with the secondary panel 32, stamped into the secondary panel 32, formed with the secondary panel 32, or coupled to the secondary panel 32 as a separate component. The hook 202 defines a generally J-shaped profile and includes a base portion 206 coupled to the secondary panel 32 and a downwardly-extending hook 208 which when brought into contact with the main panel 30 serves to engage the main panel 30, or a portion of the main panel 30, in order to limit the movement of the main panel 30 vertically and in one direction laterally. Illustratively, the hook 208 defines a slot 210.
The main panel 30 also includes a mating feature, such as the hook, 204 which may also be integrally molded, stamped, or formed with the main panel 30, or may be separately formed and then coupled to the main panel 30 as a separate component. The hook 204 of the main panel 30 similarly includes a base portion 212 coupled to the main panel 30 and an upwardly-extending hook, or pin, 214 which engages the hook 202 of the secondary panel 32 when the rear drag reduction mechanism 12 is in the fully-opened position. In an alternative embodiment (not shown), the mating shapes may be triangular, curved, or faceted in any suitable geometry that allows the two panels 30, 32 to become matingly-engaged with one another. As the rear drag reduction system 12 is moved to the fully-opened position, the bottom hook portion 214 is received within the sot 210 of the upper hook portion 208 while the upper hook portion 208 is received within a slot 216 of the bottom hook portion 214. As the rear drag reduction system 12 is moved to the fully-closed position, the bottom hook portion 214 is automatically removed from within the slot 210 of the upper hook portion 208, and the upper hook portion 208 is removed from within the lower slot 216, as the swing doors 14 of the trailer 10 are opened in order to allow the panel 32 to fold over the panel 30.
Illustratively, while the various locking mechanism embodiments have been shown in figures and described above, it should be understood the present disclosure includes any locking mechanism including a first portion, such as the illustrative pin 106 and illustrative hook 204, coupled to or integrally formed with one of the main wall panel 30 and the secondary wall panel 32. This first portion may extend upwardly above the top edge 36 of the main wall panel 30, or below a bottom surface of the secondary panel 32, and is configured to engage a second portion, such as the illustrative latch 102 and illustrative hook 202, coupled to or integrally formed with the other one of the main wall panel 30 and the secondary wall panel 32. In other words, the components of the locking mechanisms described herein may be coupled to either the main wall panel 30 and the secondary wall panel 32 such that each panel 30, 32 includes one component of the locking mechanism that is releasably coupled with a mating component of the locking mechanism that coupled to the other panel 30, 32.
As discussed above, the illustrative main wall panel 30 shown in FIGS. 1-5 is coupled to the vertical member 27 of the rear frame 13 of the trailer 10 by a plurality of hinges 29. Further, the rear swing door 14 is also coupled to the vertical member 27 of the rear frame 13 of the trailer 10 by a plurality of hinges 28, shown in FIG. 1, that are aligned with the hinges 29 to define the same pivot axis 53 about which both the rear swing door 14 and the main wall panel 30 pivot. Alternatively, as shown in FIG. 7, however, the main wall panel 30 may be coupled to the rear swing door 14 of the trailer by an alternative hinge 129. The alternative hinge 129 includes a first hinge plate 130 coupled to the inner surface 83 of the main wall panel 30, a second hinge plate 131 coupled to an outer surface of the rear swing door 14 near the vertical member 27 of the rear frame 13 of the trailer 10, and a hinge portion between the first and second hinge plate 130, 131 which defines a pivot axis 153 offset from the pivot axis 53 of the hinge 29 coupling the rear swing door 14 to the rear frame 13 of the trailer 10. Illustratively, the alternative hinge 129 further includes a mounting plate 132 positioned between the second hinge plate 131 and the outside surface of the rear swing door 14. It should be understood that while the particular hinge 129 is shown in FIG. 7, any suitable hinge may be provided which allows for pivotable movement of the main wall panel 30 that is offset from the pivot axis 53 of the hinges 29 for the rear swing door 14 in order to allow the main wall panel 30 to hingedly move relative to the rear frame assembly 13 of the trailer.
As is further shown in FIG. 7, the main wall panel 30 includes a cut-out portion 150 formed on an inside edge of the main wall panel 30. The cut-out portion 150 is formed to cooperate with the hinge 28 coupling the rear swing door 14 to the rear frame 13 of the trailer 10. The cut-out portion 150 allows the main wall panel 30 to pivot about axis 153 around the hinge 28 without interfering with the hinge 28 for the rear swing door 14.
While the invention has been illustrated and described in detail in the foregoing drawings and description, the same is to be considered as illustrative and not restrictive in character, it being understood that only illustrative embodiments thereof have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.

## Claims

1. A rear aerodynamic drag reduction system configured to be coupled to a rear frame assembly of a trailer including a rear frame and a rear swing door, the drag reduction system comprising:
a main wall panel configured to be coupled to the rear frame assembly to extend generally rearwardly of the trailer at least partially along a height of the trailer, wherein the main wall panel is movable relative to the rear frame assembly between a deployed position and a stowed position;
a secondary wall panel configured to be movably coupled to the rear swing door of the trailer to extend generally rearwardly of the trailer at least partially along a width of the trailer, wherein the secondary wall panel is movable relative to the rear frame assembly between a deployed position and a stowed position; and
a locking mechanism configured to releasably couple the main wall panel and the secondary wall panel to each other to prevent relative movement between the main wall panel and the secondary wall panel when the main and secondary wall panels are in their deployed positions,
wherein the locking mechanism includes (i) a latch coupled to the one of the main wall panel and the secondary wall panel, the latch defining a slot, and (ii) a pin coupled to the other of the main wall panel and the secondary wall panel,
wherein the pin is received within the slot when the main and secondary wall panels are in their deployed positions, and
wherein the latch extends downwardly below an inner surface of the secondary wall panel and the pin extends upwardly above a top edge of the main wall panel when the main and secondary wall panels are in the deployed positions.

2. The rear aerodynamic drag reduction system of claim 1, wherein the main wall panel is configured to be pivotably coupled to the rear frame assembly, and the secondary wall panel is configured to be pivotably coupled to the rear swing door.

3. The rear aerodynamic drag reduction system of claim 2, wherein the main wall panel is configured to be pivotably coupled to the rear swing door of the rear frame assembly, and wherein the main wall panel is configured to pivot about an axis offset from an axis about which the rear swing door pivots.

4. The rear aerodynamic drag reduction system of claim 2, wherein the main wall panel is configured to be pivotably coupled to a vertical member of the rear frame of the rear frame assembly, and wherein the main wall panel is configured to pivot about an axis aligned with an axis about which the rear swing door pivots.

5. The rear aerodynamic drag reduction system of claim 1, wherein the locking mechanism includes a first portion coupled to the main wall panel and a second portion coupled to the secondary wall panel, and wherein the first and second portions are configured to releasably engage each other.

6. The rear aerodynamic drag reduction system of claim 1, wherein the latch is coupled to an inner surface of the secondary wall panel and the pin is coupled to an inner surface of the main wall panel.

7. The rear aerodynamic drag reduction system of claim 6, wherein the secondary wall panel includes an outer edge and a bottom edge when the secondary panel is in the deployed position, wherein the main wall panel includes a rear edge and a top edge when the main wall panel is in the deployed position, and wherein the latch is adjacent the outer and bottom edges of the secondary wall panel and the pin is adjacent the rear and top edges of the main wall panel.

8. The rear aerodynamic drag reduction system of claim 6, wherein the pin includes a head received within the slot when the main and secondary wall panels are in their deployed positions, and a body coupled to the inner surface of the main wall panel.

9. The rear aerodynamic drag reduction system of claim 8, wherein the body of the pin includes an upper portion offset from a lower portion.

10. The rear aerodynamic drag reduction system of claim 1, wherein the latch is integrally formed with the secondary wall panel and the pin is integrally formed with the main wall panel.

11. The rear aerodynamic drag reduction system of claim 1, wherein the locking mechanism is automatically moved to a locked position when a user moves the rear swing door to a fully-closed position, and the locking mechanism is automatically moved to an unlocked position when a user moves the rear swing door to a fully-opened position.

12. The rear aerodynamic drag reduction system of claim 11, wherein the main wall panel is automatically moved to the deployed position when a user moves the rear swing door to a fully-closed position, and wherein the main wall panel is automatically moved to the stowed position when a user moves the rear swing door to a fully-opened position.

13. A rear aerodynamic drag reduction system configured to be coupled to a rear frame assembly of a trailer including a rear frame and a rear swing door, the drag reduction system comprising:
a main wall panel configured to be coupled to a vertical member of the rear frame to extend generally rearwardly of the trailer at least partially along a height of the trailer;
a secondary wall panel configured to be coupled to the rear swing door of the trailer to extend generally rearwardly of the trailer at least partially along a width of the trailer; and
a locking mechanism having a first portion coupled directly to the main wall panel and a second portion coupled directly to the secondary wall panel, wherein the first and second portions of the locking mechanism are coupled to each other when the main wall panel and the secondary wall panel are configured to extend rearwardly of the trailer,
wherein the main wall panel is movable between a deployed position and a stowed position, wherein the secondary wall panel is movable between a deployed position and a stowed position, wherein the main wall panel is automatically moved to the deployed position and the first and second portions of the locking mechanism are automatically engaged with each other when a user moves the rear swing door to a fully-closed position.

14. The rear aerodynamic drag reduction system of claim 13, wherein the first and second portions of the locking mechanism are automatically disengaged with each other as the main and secondary wall panels are moved to the stowed position.

15. The rear aerodynamic drag reduction system of claim 12, wherein the secondary wall panel includes a first portion configured to be coupled to a top of the rear swing door and a second portion pivotably coupled to the first portion for movement about an axis parallel to a top edge of the rear swing door, and wherein the second portion of the locking mechanism is coupled to the second portion of the secondary wall panel.

16. The rear aerodynamic rear drag reduction system of claim 15, wherein the second portion of the secondary wall panel is configured to engage a top edge of the main wall panel when the main wall panel is in the deployed position, and wherein an inner surface of the second portion of the secondary wall panel is configured to engage and lie adjacent to an outer surface of the main wall panel when the main wall panel is in the stowed position.

17. A rear aerodynamic drag reduction system configured to be coupled to a rear frame assembly of a trailer including a rear frame and a rear swing door, the drag reduction system comprising:
a main wall panel configured to be pivotably coupled to a vertical member of the rear frame to extend generally rearwardly of the trailer at least partially along a height of the trailer;
a secondary wall panel configured to be pivotably coupled to the rear swing door of the trailer to extend generally rearwardly of the trailer at least partially along a width of the trailer; and
a locking mechanism configured to releasably lock the main wall panel and the secondary wall panel to each other, the locking mechanism having (i) a first portion coupled directly to the main wall panel to extend above the main wall panel and (ii) a second portion coupled directly to an inside surface of the secondary wall panel,
wherein the main wall panel and the secondary wall panel are movable relative to the rear frame assembly between deployed positions and stowed positions, and
wherein the first portion of the locking mechanism is automatically received within a slot of the second portion of the locking mechanism when the main wall panel and the secondary wall panel are moved to their deployed positions.