Abstract:
An apparatus for converting a substantially flat vehicular surface on the rear of a vehicle so as to create at least one surface which operates to reduce aerodynamic drag, comprising: at least one support adapted to be moveably attached to the rear surface of a vehicle; at least one surface supported by the at least one support; the at least one surface movably position so as to move from deployed position extending from the rear of a vehicle to a retracted position; whereby the apparatus operates to reduce aerodynamic drag in the deployed position and does not interfere with vehicle loading in the retracted position.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Various air foils have being used to reduce drag on tractor-semi trailer systems (or eighteen wheelers). For instance, truck cabs commonly have an air foil on top of the cab for air flow to reduce drag. Trailer Tail™ available from AeroRig Solutions provides an extension on the rear of a truck to reduce drag as advertised at http://aerorigsolutions.com/. Another example is the “Boat tail” from Clarkson University. Further examples of efforts to reduce truck aerodynamic drag are found at “Truck Manufacturers Program to Reduce Aerodynamic Drag” by Robert M. Clark, ClarkeTruck Manufacturers Association, Further examples are found in DOE Heavy Vehicle Systems Optimization Merit Review, April 2006. However, the truck extensions of the prior art appeared to fixedly and/or manually implemented and produce hazardous conditions in that extensions to the back of a truck may result in increased frequency of accidents and bumping of the trailer and inhibits use during loading and unloading. 
       SUMMARY OF THE PRESENT INVENTION 
       [0002]    A preferred embodiment apparatus for converting a substantially flat vehicular surface on the rear of a vehicle so as to create at least one surface which operates to reduce aerodynamic drag, comprising: at least one support adapted to be moveably attached to the rear surface of a vehicle; at least one surface supported by the at least one support; the at least one surface movably position so as to move from deployed position extending from the rear of a vehicle to a retracted position; whereby the apparatus operates to reduce aerodynamic drag in the deployed position and does not interfere with vehicle loading in the retracted position. 
         [0003]    A preferred embodiment comprises aerodynamic apparatus for vehicles comprising at least one support adapted to be removably positioned on the rear of a vehicle from an deployed position to a retracted position; at least one movable surface supported by the at least one support; whereby the at least one surface operates to deflect air. 
         [0004]    A preferred embodiment provides a removable and/or movable extension behind a truck, bus, van or similar vehicle which becomes operative at speeds above a certain minimum. One preferred embodiment extends from the rear of a vehicle to effectively produce the tail of a “tear drop” shaped extension. 
         [0005]    A preferred embodiment provides a truck or vehicle extension which optionally collapses automatically at low speeds and extends at high speeds when most beneficial. A preferred embodiment extension is minimal in size at slow speeds or stand still, when interference with other vehicles is a possibility. Extension at higher speeds provides limited interference with traffic conditions and vehicular maneuvering. 
         [0006]    A preferred embodiment provides a self inflating actuation in which air flow enters the cavity, and extends the cavity to a desired shape to create an aerodynamic effect. 
         [0007]    To achieve an aerodynamic effect, an extension is mounted to the rear of a vehicle which extends from the vehicle rear at speeds when the aerodynamic effect is achieved. Optionally, at low speeds or a stand still, the extension recedes or collapses so as to not to interfere with parking of the vehicle or interfere with other vehicles. At deployment speeds, vehicles are commonly spaced from one another in traffic, so the extension does not provide interference. Yet in bumper to bumper traffic, the extension may optionally recede to facilitate traffic maneuvering. The extension promotes laminar flow and reduces the effects of drag. 
         [0008]    Deployment from the top of the vehicle or retract ability results in less interference with the opening of the trailer doors and loading unloading of the trailer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: The drawings of this invention are illustrative and diagrammatic in nature in order to present the principles of the invention. They are being provided as examples without limiting the invention to the specific configuration or dimensions shown. 
           [0010]      FIG. 1  is a schematic illustration of a preferred embodiment comprising supports  11 ,  12 ,  13 ,  14 ,  15 ,  16 ,  17 , and  18  interconnected by a covering, such as plastic. 
           [0011]      FIG. 2  is a schematic illustration of the preferred embodiment of  FIG. 1  pivoted to the top of the vehicle. 
           [0012]      FIG. 3  is a schematic illustration of the preferred embodiment of  FIG. 1  pivoted to the top of the vehicle in a collapsed state. 
           [0013]      FIG. 4  is a schematic illustration of a preferred embodiment  FIG. 2  is a schematic illustration of the preferred embodiment of pivoted to the top of the vehicle having collapsible links or elements  17 A,  18 A. 
           [0014]      FIG. 5  is a schematic side view illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  21 . 
           [0015]      FIG. 6  is a schematic top view illustration of the preferred embodiment of  FIG. 5 . 
           [0016]      FIG. 7  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  21 . 
           [0017]      FIG. 8  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  21  and an air intake  22 . 
           [0018]      FIG. 9  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  21  and an air intake  22  in a position on top of the vehicle. 
           [0019]      FIG. 10  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  21  and an air intake  22  incrementally shown from a deployed position to in a position on top of the vehicle; optionally driven by a motor  88 M. 
           [0020]      FIG. 11  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  21  and an air intake  22 , further comprising a pivotable inlet  23  biased by a spring  24 . 
           [0021]      FIG. 12  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  21  and an air intake  22 , further comprising a pivotable inlet  23  biased by a spring  24  in a direction opposite to that of the embodiment of  FIG. 11 . 
           [0022]      FIG. 13  is a schematic side view illustration of a preferred embodiment vehicle extender comprising panels  32 ,  33  (not shown). 
           [0023]      FIG. 14  is a schematic top view illustration of a preferred embodiment vehicle extender comprising panels  32 ,  33  biased by springs  34 . 
           [0024]      FIG. 15  is a schematic illustration of a preferred embodiment vehicle extender comprising panels  32 ,  33  biased by inflatable chambers or tubular elastic material elements  35 . 
           [0025]      FIG. 16  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  41  optionally positionable on a pivotable support  31 . 
           [0026]      FIG. 17  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  42  optionally positionable on a pivotable support  31 . 
           [0027]      FIG. 18  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  42  optionally positionable on a pivotable support  31  and optionally comprising a pump. 
           [0028]      FIG. 19  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  43  optionally positionable on a pivotable support  31  and optionally comprising a pump and a flexible or rigid middle support. 
           [0029]      FIG. 20  is a progressive schematic illustration of the preferred embodiment vehicle extender of  FIG. 19  comprising an inflatable chamber  43  optionally positionable on a pivotable support  31  and optionally comprising a pump and a flexible or rigid middle support. 
           [0030]      FIG. 21  is a progressive schematic illustration of the preferred embodiment vehicle extender of  FIG. 19  comprising an inflatable chamber  43  optionally positionable on a pivotable support  31  and optionally comprising a pump and a flexible or rigid middle support. 
           [0031]      FIG. 22  is a progressive schematic illustration of the preferred embodiment vehicle extender of  FIG. 19  comprising an inflatable chamber  43  optionally positionable on a pivotable support  31  and optionally comprising a pump and a flexible or rigid middle support. 
           [0032]      FIG. 23  is a progressive schematic illustration of the preferred embodiment vehicle extender of  FIG. 19  comprising an inflatable chamber  43  optionally positionable on a pivotable support  31  and optionally comprising a pump and a flexible or rigid middle support. 
           [0033]      FIG. 24  is a schematic illustration of the preferred embodiment vehicle extender of  FIG. 19  comprising an inflatable chamber  43  optionally positionable on a pivotable support  31  and optionally comprising a pump and a flexible or rigid middle support and optionally comprising telescoping guides. 
           [0034]      FIG. 25  is a schematic illustration of the preferred embodiment vehicle extender comprising an inflatable chamber  44  optionally positionable on a pivotable support  31  and optionally comprising a pump and a middle support and optionally comprising telescoping guides. 
           [0035]      FIG. 26  is a side view schematic illustration of the preferred embodiment vehicle extender comprising an inflatable chamber  44 A optionally positionable on a pivotable support  31  and optionally comprising a pump and a middle support and optionally comprising telescoping guides (not shown). 
           [0036]      FIG. 27  is a side view schematic illustration of the preferred embodiment vehicle extender comprising inflatable chamber  44 B optionally positionable on a pivotable support  31  and optionally comprising a pump and optionally comprising telescoping guides (not shown). 
           [0037]      FIG. 28  is a schematic illustration of the preferred embodiment vehicle extender comprising inflatable chamber  44  or  44 A optionally positionable on a pivotable support  31  and optionally comprising a pump and optionally comprising telescoping guides and a semi-rigid center panel. 
           [0038]      FIG. 29  is a schematic illustration of the preferred embodiment vehicle extender comprising inflatable chamber  44  or  44 A optionally positionable on a pivotable support  31  and optionally comprising louvered air inlets and optionally comprising telescoping guides (not shown) and a semi-rigid center panel. 
           [0039]      FIG. 30  is a schematic illustration of the preferred embodiment vehicle extender comprising inflatable chamber  45  optionally positionable on a pivotable support  31  and optionally comprising louvered air inlets and optionally comprising telescoping guides (not shown) and a semi-rigid center panel. 
           [0040]      FIG. 31  is a schematic illustration of the preferred embodiment vehicle extender comprising a detachable inflatable chamber  45  optionally positionable on a pivotable support  31  and optionally comprising louvered air inlets that are motor driven by a radio controlled motor and optionally comprising telescoping guides (not shown) and a semi-rigid center panel. 
           [0041]      FIG. 32  is a schematic illustration of the preferred embodiment vehicle extender  47  having sides positioned on the trailer doors. 
           [0042]      FIG. 33  is a schematic illustration of optional cross sections the preferred embodiment vehicle extender having sides positioned on the trailer doors. 
           [0043]      FIG. 34  is a schematic illustration of the preferred embodiment vehicle extender  47  showing only a single trailer door of the embodiment of  FIG. 32 . 
           [0044]      FIG. 35  is a top view of a schematic illustration of the preferred embodiment vehicle extender  48  positioned on trailer doors. 
           [0045]      FIG. 36  is a side view of a schematic illustration of the preferred embodiment vehicle extender  48  positioned on trailer doors. 
           [0046]      FIG. 37A  is a side view of a schematic illustration of the preferred embodiment vehicle extender showing a motor driven lifting assembly. 
           [0047]      FIG. 37B  is a side view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 37A  in a lifted position. 
           [0048]      FIG. 37B  is a side view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 37A  in a lifted position. 
           [0049]      FIG. 37C  is a side view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 37A  in a ¾ lifted position. 
           [0050]      FIG. 37D  is a side view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 37A  in a retracted position. 
           [0051]      FIG. 38A  is a side view of a schematic illustration of the preferred embodiment vehicle extender showing cylindrical assembly  60 ,  61 . 
           [0052]      FIG. 38B  is a side view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 38A  in a deployed position. 
           [0053]      FIG. 39  a perspective view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 38A . 
           [0054]      FIG. 40  a perspective view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 38A  prior to inflation. 
           [0055]      FIG. 41  a perspective view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 38A  prior to inflation showing channels  62 A. 
           [0056]      FIG. 42  a perspective view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 38A  after inflation; the configuration may be any one of  21 ,  41 ,  42 ,  43 ,  44 A,  44 B,  47 ,  48 , and the chamber may be inflated by an air inlet, such as for example, as shown in  FIG. 12  or a pump. 
           [0057]      FIG. 43  a perspective view of a schematic illustration of the preferred embodiment vehicle extender of  44 A after inflation 
           [0058]      FIG. 44A  is a schematic illustration of an assembly  61  comprising a reversible motor  63 . 
           [0059]      FIG. 44B  is a schematic illustration of an assembly  61  comprising a coiled spring drive  63 A. 
           [0060]      FIG. 44   c  is a schematic illustration of an assembly  61  comprising a cogged drive  63 B. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0061]    The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like reference numerals refer to like elements throughout the description of the figures. 
         [0062]    It will be understood that when an element is referred to as being “on” another element, it can be directly on the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected or coupled” to another element, there are no intervening elements present. Furthermore, “connected” or “coupled” as used herein may include wirelessly connected or coupled. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
         [0063]    It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first layer could be termed a second layer, and, similarly, a second layer could be termed a first layer without departing from the teachings of the disclosure. 
         [0064]    The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof. 
         [0065]    Furthermore, relative terms, such as “lower” or “bottom” and “upper” or “top,” “left” or right” may be used herein to describe one element&#39;s relationship to other elements as illustrated in the Figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. For example, if the device in one of the figures were turned over, elements described as being on the “lower” side of other elements would then be oriented on “upper” sides of the other elements. The exemplary term “lower”, can therefore, encompass both an orientation of “lower” and “upper,” depending of the particular orientation of the figure. Similarly, if the device in one of the figures is turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements. The exemplary terms “below” or “beneath” can, therefore, encompass both an orientation of above and below. 
         [0066]    Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
         [0067]    Shown in  FIG. 1  is a truck tail extender in the deployed position. The extender comprises supports  11 ,  12 ,  13  and  14  which may conform or track the shape of the rear of the vehicle, which in the  FIG. 1  example is a truck. The supports  11 ,  12 ,  13  and  14  may comprise a rigid frame. In is intended that a covering extend between supports  11 ,  15 ,  16 ; supports  12 ,  17 ,  15 , supports,  13 ,  17 ,  17 , and supports  14 ,  15 ,  16 . The covering may be, for example, plastic, or canvas In addition supports  15  and  16  may form a rigid frame also. Supports  17  and  18  may be telescopic or extendable. 
         [0068]    Shown in  FIG. 2  is the extender in a pivoted position on the trailer or vehicle roof. The section defined by supports  11 ,  15 , and  16  may lie against the trailer top. The support  11  may be similar to an axle upon which the extender  10  pivots. The section defined by supports  11 ,  15  and  16  may remain rigid while the supports  17  and  18  collapse to a position near the truck top. Supports  17 ,  18  may be telescopic so as to position the support  13  relatively close to the top of the vehicle. Optionally the extender comprises a latch  19 . In between the supports  11 ,  15 , and  16  may be clear plastic. 
         [0069]    In the preferred embodiment  10 A of  FIG. 4 , supports  17  and  18  are formed by the corners  17 A and  18 A of an inflatable enclosure resembling a bag formed of clear plastic or the like. The bag resembles a triangular prism. Frame  11 ,  12 ,  13 ,  14  is rigid and surrounds the plastic inflatable enclosure. Frame  11 ,  12 ,  13 ,  14  is pivotable upon an axle or the like and may be pivoted by a motor  88 M, which may be positioned to either side (or motors on both sides) or in the interior of the corners of the trailer. The motor may be electrically controlled from the vehicle cab. 
         [0070]    Conversely in the summer time, an infrared sensing device may be positioned on the inside of an apartment unit or building. If a window or door is opened, the heat will be sensed by the infrared sensor. 
         [0071]      FIG. 5  is a schematic side view illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  21 . The inflatable chamber may be formed of an elastic material, expandable plastic or the like. Alternatively, it may be formed of the material used for air bags. Although supports  11 ,  12 ,  13 , and  14  are pictured in  FIGS. 5-8  the inflatable chamber may be fastened to the end of the vehicle. 
         [0072]      FIG. 6  is a schematic top view illustration of the preferred embodiment of  FIG. 5 . 
         [0073]      FIG. 7  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  21 . 
         [0074]      FIG. 8  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  21  and an air intake  22 . The air intake may be covered when the extender is not deployed and is uncovered upon deployment of the extender on the back of the vehicle. 
         [0075]      FIG. 9  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  21  and an air intake  22  in a position on top of the vehicle. The air intake may be covered when the extender is not deployed and is uncovered upon deployment of the extender on the back of the vehicle. 
         [0076]      FIG. 10  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  21  and an air intake  22  incrementally shown from a deployed position to in a position on top of the vehicle; optionally driven by a motor  88 M. The motor  88 M may be reversible and controlled from the interior of the vehicle either by wire or a radio (or blue tooth) connection. The air chamber may be supported by a support  31  which may comprise a flat panel, sheet or a plurality of elements arranged in a frame-like matter. The support  31  is pivotable from a deployed position shown in solid lines and to a retracted position substantially parallel to the top surface of the vehicle. Positioning of the support surface  31  close and parallel to the top surface of the vehicle prevents interference when the vehicle passes underneath a bridge or sign. Upon positioning in a deployed position, the inflatable chamber  21  may be inflated by a pump or by airflow entering from the exterior. Optionally an outlet may be operatively connected to the chamber  21  for release of the air. A programmable controller or processor may be used to operate the motor, such that the motor is operated only when the vehicle is stopped and there is clearance for movement of the support  31 . Clearance detection may be accomplished through a detector. 
         [0077]      FIG. 11  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  21  and an air intake  22 , further comprising a pivotable inlet  23  biased by a spring  24 . As the vehicle moves, air flows into the inlet  23  and into inflatable chamber  21 . 
         [0078]      FIG. 12  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  21  and an air intake  22 , further comprising a pivotable inlet  23  biased by a spring  24  in a direction opposite to that of the embodiment of  FIG. 11 . The inlet  23  of  FIG. 12  may be such that as vehicular speed increases, the opening of intake  23  is maximized. The air flows into chamber  22  into the inflatable chamber  21 . When the support  31  is retracted, the support  31  covers the inlet  23  which pivots to a position substantially adjacent to the top of the vehicle. A spring is used to bias the intake  23  into opening. 
         [0079]      FIG. 13  is a schematic side view illustration of a preferred embodiment vehicle extender comprising panels  32 ,  33  (not shown). The panels  32 ,  33  include a top curvature which effectively cams the panels  32 ,  33  into closure against the support  31 . Support  31  may be pivotably driven by a motor  88 M. The motor  88 M may be reversible and optionally controlled by the operator of the vehicle from inside the interior of the vehicle. Optionally, a programmer/controller may be used to operate the motor only when the vehicle is stopped and there ample clearance for the support  31  from a deployed position to a retracted position. A sensor may be used to detect interference with the movement, such as the sensors which stop an elevator door when interference is detected. The programmer/controller, motor  88 M and sensor may optionally included with all embodiments having support  31 . 
         [0080]      FIG. 14  is a schematic top view illustration of a preferred embodiment vehicle extender comprising panels  32 ,  33  biased by springs  34 . The supports  34  H may comprise a hinge which limits opening or pivoting of the panels  32 ,  33 . Springs  34  bias the panels  32 ,  33  into an open position. Returning again to  FIG. 13 , the panels  32 ,  33  may include a curvature on the upper portion to induce a camming effect or closure or pivoting towards the support  31  into a compact position on the vehicular top. 
         [0081]      FIG. 15  is a schematic illustration of a preferred embodiment vehicle extender comprising panels  32 ,  33  biased by inflatable chambers or tubular elastic material elements  35 . The embodiment of  FIG. 15  comprising the elements of  FIG. 14  except that the springs are replaced by elastic elements  35  which may be solid elastic or an inflatable chamber. 
         [0082]      FIG. 16  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  41  optionally positionable on a pivotable support  31 . The chamber  41  substantially resembles a pyramid. 
         [0083]      FIG. 17  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  42  optionally positionable on a pivotable support  31 . The chamber  41  is substantially triangular in a cross-section taken in a plane parallel to the ground. 
         [0084]      FIG. 18  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  42  optionally positionable on a pivotable support  31  and optionally comprising a pump. All of the inflatable chambers described in this application (not having an air intake  22 ) may be inflated by a pump and although the pump is positioned as shown, it may be positioned anywhere on the vehicular body and connected to the chamber by tubing. All of the inflatable chambers described in this application may also have an air release associated with it for release of air, optionally under the control of the vehicle driver from within the cab. Optionally, all of the chamber may have the air sucked out of the chamber to collapse the chamber into a compact mode or form. The suction device may comprise a vacuum pump device which removes air as described in vacuum pumps at http://www.gastmfg.com/vphb/vphb_s4.pdf, and hereby incorporated by reference. 
         [0085]      FIG. 19  is a schematic illustration of a preferred embodiment vehicle extender comprising an inflatable chamber  43  optionally positionable on a pivotable support  31  and optionally comprising a pump, vacuum pump, and a flexible or rigid middle support. As used herein the inflatable chambers  31  may be formed of an elastic material such as plastic which is expandable. Optionally, in all embodiments herein the air chamber may be formed of clear plastic or elastic material. The flexible or rigid support may be a plastic support which forms an integral corner element with the expandable plastic. 
         [0086]      FIG. 20  is a progressive schematic illustration of the preferred embodiment vehicle extender of  FIG. 19  comprising an inflatable chamber  43  optionally positionable on a pivotable support  31  and optionally comprising a pump and a flexible or rigid middle support. 
         [0087]      FIG. 21  is a progressive schematic illustration of the preferred embodiment vehicle extender of  FIG. 19  comprising an inflatable chamber  43  optionally positionable on a pivotable support  31  and optionally comprising a pump and a flexible or rigid middle support. 
         [0088]      FIG. 22  is a progressive schematic illustration of the preferred embodiment vehicle extender of  FIG. 19  comprising an inflatable chamber  43  optionally positionable on a pivotable support  31  and optionally comprising a pump and/or vacuum pump and/or a flexible or rigid middle support. 
         [0089]      FIG. 23  is a progressive schematic illustration of the preferred embodiment vehicle extender of  FIG. 19  comprising an inflatable chamber  43  optionally positionable on a pivotable support  31  and optionally comprising a pump and a flexible or rigid middle support. 
         [0090]      FIG. 24  is a schematic illustration of the preferred embodiment vehicle extender of  FIG. 19  comprising an inflatable chamber  43  optionally positionable on a pivotable support  31  and optionally comprising a pump and a flexible or rigid middle support and optionally comprising telescoping guides  83 T. The telescopic guides may be driven by hydraulically or electronically by solenoid. 
         [0091]      FIG. 25  is a schematic illustration of the preferred embodiment vehicle extender comprising an inflatable chamber  44  optionally positionable on a pivotable support  31  and optionally comprising a pump and a middle support and optionally comprising telescoping guides. The telescopic guides may be driven by hydraulically or electronically by solenoid. 
         [0092]      FIG. 26  is a side view schematic illustration of the preferred embodiment vehicle extender comprising an inflatable chamber  44 A optionally positionable on a pivotable support  31  and optionally comprising a pump and/or vacuum pump and/or a middle support and optionally comprising telescoping guides (not shown). 
         [0093]      FIG. 27  is a side view schematic illustration of the preferred embodiment vehicle extender comprising inflatable chamber  44 B optionally positionable on a pivotable support  31  and optionally comprising a pump, and/or vacuum pump and optionally comprising telescoping guides (not shown). 
         [0094]      FIG. 28  is a schematic illustration of the preferred embodiment vehicle extender comprising inflatable chamber  44  or  44 A optionally positionable on a pivotable support  31  and optionally comprising a pump and optionally comprising telescoping guides and a semi-rigid center panel. The optional telescopic guides  83 T in  FIGS. 25 and 28  facilitate the extension and withdrawal of the end of the chamber. The optional telescopic guides may be powered hydraulically or electronically by a solenoid. Optionally a rear panel may be retracted towards the rear of the vehicle upon actuation/operation of one or more telescopic guides  83 T. In all embodiments herein containing an optional panel in the rear, the panel may be plastic, aluminum or the like and, if plastic, may be clear vinyl. 
         [0095]      FIG. 29  is a schematic illustration of the preferred embodiment vehicle extender comprising inflatable chamber  44  or  44 A optionally positionable on a pivotable support  31  and optionally comprising louvered air inlets and optionally comprising telescoping guides (not shown) and a semi-rigid center panel. The air inlets may be optionally controlled by solenoids for opening and closure which may optionally controlled inside of the vehicle by the driver. 
         [0096]      FIG. 30  is a schematic illustration of the preferred embodiment vehicle extender comprising inflatable chamber  45  optionally positionable on a pivotable support  31  and optionally comprising louvered air inlets and optionally comprising telescoping guides (not shown) and a semi-rigid center panel. The inflatable chamber is inflated by air flow entering the cavity as the vehicle moves, the entering air extending the cavity to a desired shape to create an aerodynamic effect when the inflatable chamber inflates and operating to collapse into a retracted position when the vehicle is not moving. In the retracted position, the exterior of the inflatable chamber optionally extends a maximum of six inches from the support  31 . The air inlets may be optionally controlled by solenoids for opening and closure which may optionally controlled inside of the vehicle by the driver. The chamber may be collapse using a vacuum pump as described herein. 
         [0097]      FIG. 31  is a schematic illustration of the preferred embodiment vehicle extender comprising a detachable inflatable chamber  45  optionally positionable on a pivotable support  31  and optionally comprising louvered air inlets that are motor driven by a radio controlled motor and optionally comprising telescoping guides (not shown) and a semi-rigid center panel. The air chamber shown may be attached to the vehicle by hooks or snaps  46 . Optionally a hook and loop fastener (under the trademark Velcro) may be used. Instead of louvers, a pump and vacuum pump may be used to inflate and deflate the chamber  45 . 
         [0098]      FIG. 32  is a schematic illustration of the preferred embodiment vehicle extender  47  having sides positioned on the trailer doors. The two sides may be separately mounted so that each is placed on a door of the vehicle so that the doors may be moved or pivoted while the chamber halves are in place. 
         [0099]      FIG. 33  is a schematic illustration of optional cross sections the preferred embodiment vehicle extender  47  having sides positioned on the trailer doors. 
         [0100]      FIG. 34  is a schematic illustration of the preferred embodiment vehicle extender  47  showing only a single trailer door of the embodiment of  FIG. 32 . 
         [0101]      FIG. 35  is a top view of a schematic illustration of the preferred embodiment vehicle extender  47 ,  48  positioned on trailer doors. 
         [0102]      FIG. 36  is a side view of a schematic illustration of the preferred embodiment vehicle extender  47 ,  48  positioned on trailer doors. 
         [0103]      FIG. 37A  is a side view of a schematic illustration of the preferred embodiment vehicle extender showing a motor  88 M driven lifting assembly, comprising a cable or rope  51  and pulley subassembly  52 , which may be retractable or flexible. Optionally, the assembly may include a latch optionally controlled by a solenoid for activation from within the vehicle interior or exterior of the vehicle. 
         [0104]      FIG. 37B  is a side view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 37A  in a lifted position. 
         [0105]      FIG. 37B  is a side view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 37A  in a lifted position. 
         [0106]      FIG. 37C  is a side view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 37A  in a ¾ lifted position. 
         [0107]      FIG. 37D  is a side view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 37A  in a retracted position. 
         [0108]      FIG. 38A  is a side view of a schematic illustration of the preferred embodiment vehicle extender showing assembly  60 ,  61 . The support  31 A rolls up into chamber  61  which may be cylindrical in shape. The roll up may resemble that of a window shade, and may comprise springs which induce the roll-up. The support  31 A may for example be a sheet of flexible plastic, such as vinyl plastic, which may optionally be clear. The embodiment may optionally include a pump for inflating and/or a vacuum pump for withdrawal of the air, as described in the foregoing. The housing  61  may be removably attached to the vehicle exterior at or below the top surface of the vehicle. The housing  61  may be attached by bolts, welded or screws or the like. 
         [0109]      FIG. 38B  is a side view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 38A  in a deployed position, prior to inflation of the air chamber, which may take the configuration of any of the embodiments described above. 
         [0110]      FIG. 39  a perspective view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 38A , further comprising hooks and loop fasteners for attachment of the support  31  to the vehicle rear. Optionally a latch may be included for maintaining the position of the support  31 , which may optionally be solenoid controlled. 
         [0111]      FIG. 40  a perspective view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 38A  prior to inflation. 
         [0112]      FIG. 41  a perspective view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 38A  prior to inflation showing channels  62 A. The support  31  is constrained by the U-shaped channels to secure the support  31  against the back of the vehicle. Optionally, the channels  62 A may be removably mounted (such as by screws or bolts) to the vehicle rear. 
         [0113]      FIG. 42  a perspective view of a schematic illustration of the preferred embodiment vehicle extender of  FIG. 38A  after inflation; the configuration may be any one of  21 ,  41 ,  42 ,  43 ,  44 A,  44 B,  47 ,  48 , and the chamber may be inflated by an air inlet, such as for example, as shown in  FIG. 12  or a pump and/or vacuum pump, as described in the foregoing. 
         [0114]      FIG. 43  is a perspective view of a schematic illustration of the preferred embodiment vehicle extender  44 A after inflation. The configuration may be any one of  21 ,  41 ,  42 ,  43 ,  44 A,  44 B,  47 ,  48 , and the chamber may be inflated by an air inlet, such as for example, as shown in  FIG. 12  or a pump and/or vacuum pump, as described in the foregoing 
         [0115]      FIG. 44A  is a schematic illustration of an assembly  61  comprising a reversible motor  63 . 
         [0116]      FIG. 44B  is a schematic illustration of an assembly  61  comprising a coiled spring drive  63 A. 
         [0117]      FIG. 44   c  is a schematic illustration of an assembly  61  comprising a cogged drive  63 B. The belt  64  may be pulled by hand or powered by a motor (not shown). The term cogged means of a nature similar to a fan belt drive on a 1985 Ford or the like. 
         [0118]    As used herein the terminology “processor” or “controller” as used herein may be a microprocessor, computer, programmable controller, programmable chip, multiprocessor, personal computer, CPU, coprocessor, central processor, or the like. 
         [0119]    As used herein the terminology “external” means external to the vehicle. 
         [0120]    As used herein, the terminology “deployed position” means a position where the aerodynamic effect to reduce vehicle drag occurs. 
         [0121]    As used herein, the terminology “rolls” or “reels” means to form roll, a spool or scroll in which the surface is coiled around a central support. 
         [0122]    As used herein, the terminology “vehicle” includes the trailer of a vehicle; such as the apparatus may be affixed to the top of a trailer of a vehicle. 
         [0123]    As used herein, the terminology “axis” means a line about which a body or geometric object rotates. The axis may comprise, for example, a rod, rotating support, or pivoting support. 
         [0124]    As used herein the terminology “wake” refers to the flow of air behind a vehicle. 
         [0125]    Embodiments of the present invention are described herein are schematic illustrations of idealized embodiments of the present invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. The embodiments of the present invention should not be construed as limited to the particular shapes of displays illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. 
         [0126]    Although a few exemplary embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments, without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.