Abstract:
A sleeper cab assembly for a tractor-trailer truck. The sleeper cab assembly has a primary sleeper cab structure that is positioned behind the driver cab of the tractor-trailer. The primary sleeper cab structure has a rear wall, wherein an opening is disposed in the rear wall. A door is coupled to the rear wall for selectively opening and closing the rear wall opening. The door is selectively positionable between a vertical position, where the door obstructs the opening, and a horizontal position where the door does not obstruct the opening. An enclosure is provided for covering an area above the door when the door is in its horizontal position. The door and its covering define a secondary chamber that is accessible from the interior of the sleeper cab structure through the opening in the rear wall.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    In general, the present invention relates to the structure of tractor-trailer trucks. More particularly, the present invention relates to the structure of the sleeper cab portion of a tractor-trailer truck.  
           [0003]    2. Prior Art Statement  
           [0004]    Most goods in the United States are transported from point-to-point using trucks. The most common type of trucks used to haul large quantities of goods are tractor-trailer trucks. A tractor-trailer truck is the general name given to trucks specifically designed to pull cargo trailers. Tractor-trailer trucks and cargo trailers come in a wide variety of shapes and styles. However, in the most common configuration, a cargo trailer is a trailer that has no front wheels and eight rear wheels. The tractor-trailer truck itself has ten wheels and supports the front of the trailer. Accordingly, when the tractor-trailer truck is connected to a cargo trailer, the overall vehicle has eighteen wheels. Accordingly, such vehicles are commonly referred to as “eighteen wheelers” or “tractor trailers” in common speech.  
           [0005]    Tractor-trailer trucks come in a wide variety of models and styles depending upon the needs of a user. Two types of tractor-trailer trucks include short cab trucks and sleeper cab trucks. Tractor-trailer trucks that are used to make short hauls, or are often driven on city streets, are typically short cab trucks. In a short cab truck, there is a driver&#39;s bench and very little room behind the driver&#39;s bench. This shortens the overall length of the tractor-trailer truck and enables the tractor-trailer truck to make narrow turns in tight traffic. However, tractor-trailer trucks that are driven long distances over the nation&#39;s highways typically are sleeper cab trucks. A sleeper cab style tractor-trailer truck has a sleeper cab behind the driver&#39;s bench. This provides the driver with a place to sleep at night so that the driver does not have to check into a motel every night during a long haul.  
           [0006]    The size of a typical sleeper cab on a tractor-trailer truck is typically less than six feet. The reason for this is that the longer the sleeper cab is made, the longer the frame of the tractor-trailer truck must be made. The longer the tractor-trailer truck&#39;s frame is made, the more room that tractor-trailer truck needs on a street to turn. Accordingly, if the sleeper cab is made much longer than six feet, a tractor-trailer truck would not be able to make certain turns commonly found between narrow roads.  
           [0007]    In the small amount of space within a sleeper cab, there is typically contained a toilet, a sink, storage cabinets and a sleeping bunk. The sleeping bunk is typically folded flush against a wall to save space when not in use. When the sleeper bunk is to be used, a driver commonly must rearrange the contents of the sleeper cab to make enough room so that the sleeping bunk can be deployed into its horizontal position. Commonly, when the sleeping bunk is deployed, its structure blocks the sink and/or toilet. Accordingly, if a driver wants to use the sink or the toilet in the middle of the night, the sleeping bunk must first be moved back into its stowed orientation.  
           [0008]    When a tractor-trailer truck is connected to a cargo trailer, there is a minimum amount of articulation space that must be left open between the back of the sleeper cab and the front of the cargo trailer. This articulation space is typically between three and five feet. The reason this articulation space must be left open is that this open space is needed to prevent the structure of the sleeper cab from contacting the cargo trailer when the tractor-trailer truck pivots while making sharp turns. Accordingly, if a person were to design a longer sleeper cab, the frame of the tractor-trailer truck would have to be made longer in order to preserve the required minimum open articulation space required between the sleeper cab and the cargo trailer. As has been previously mentioned, a tractor-trailer truck with a longer frame is highly undesirable because it greatly limits the ability of the tractor-trailer truck to turn on narrow roadways.  
           [0009]    A need therefore exists for a system and method that increases the size of a sleeper cab without requiring a corresponding increase in length in the frame of the tractor-trailer truck. This need is met by the present invention as described and claimed below.  
         SUMMARY OF THE INVENTION  
         [0010]    The present invention is a sleeper cab assembly for a tractor-trailer truck. The sleeper cab assembly has a primary sleeper cab structure that is positioned behind the driver cab of the tractor-trailer. The primary sleeper cab structure has a rear wall, wherein an opening is disposed in the rear wall. A door is coupled to the rear wall for selectively opening and closing the rear wall opening. The door is selectively positionable between a vertical, position, where the door obstructs the opening, and a horizontal position where the door does not obstruct the opening. An enclosure is provided for covering an area above the door when the door is in its horizontal position. The door and its covering define a secondary chamber that is accessible from the interior of the sleeper cab structure through the opening in the rear wall.  
           [0011]    The secondary chamber is deployed when the tractor-trailer is parked. The secondary chamber extends into the articulation zone between the sleeper cab and the cargo trailer which is acceptable when the tractor-trailer is parked. The sleeper cab is typically only used when the tractor-trailer is parked. Accordingly, the space in the sleeper cab can be expanded when needed. The secondary chamber is retracted when the driver leaves the sleeper cab and again begins to drive. As such, nothing remains in the articulation zone that can interfere with the ability of the tractor-trailer to turn. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    For a better understanding of the present invention, reference is made to the following description of exemplary embodiments thereof, considered in conjunction with the accompanying drawings, in which:  
         [0013]    [0013]FIG. 1 is a side view of a tractor-trailer having the sleeper cab configuration of the present invention shown in a retracted position;  
         [0014]    [0014]FIG. 2 is a side view of a tractor-trailer having the sleeper cab configuration of the present invention shown in a deployed position;  
         [0015]    [0015]FIG. 3 is a selectively cross-sectioned view of the segment of FIG. 2 containing the sleeper cab and the articulation zone behind the sleeper cab;  
         [0016]    [0016]FIG. 4 is a side view of the exterior of the sleeper cab when the extending section is deployed; and  
         [0017]    [0017]FIG. 5 is a cross-sectional view of an alternate embodiment of the present invention sleeper cab configuration. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0018]    The present invention is a system and method for extending the sleeper cab of a tractor-trailer into the unused articulation zone that is present between the sleeper cab and the front of a cargo trailer. Since the articulation zone is unimportant when the tractor-trailer is parked, this space can be temporarily utilized to expand the sleeper cab when the driver of the truck is not driving and is using the sleeper cab. Once the driver is ready to drive, the extended sleeper cab is retracted and the articulation zone is again unused.  
         [0019]    Referring to FIG. 1, a tractor-trailer  10  is shown. The tractor-trailer  10  contains a tractor-trailer truck  12  that is pulling a cargo trailer  14 . The tractor-trailer truck  14  has a driver cab  16  in which the driver sits when driving the tractor-trailer  10 . Behind the driver cab  16  is a sleeper cab  18  that is used by the driver when the driver is resting. The sleeper cab  18  has the same width as does the driver cab  18  and extends a predetermined distance D1 behind the driver cab  16 . The predetermined distance D1 can be any distance between two feet and ten feet, with the average sleeper cab extending approximately six feet behind the driver cab  16 .  
         [0020]    The articulation zone  20  between the rear of the sleeper cab  18  and the front of the cargo trailer  14  has a predetermined distance D2, which is at least three feet. As can be seen by now referring to both FIG. 1 and FIG. 2, an extendable section  22  of the sleeper cab  18  is selectively deployable between a retracted position and a deployed position. FIG. 1 shows the sleeper cab  18  having the extendable section  22  in a retracted position. When the extendable section  22  of the sleeper cab  18  is in its retracted position, the articulation zone  20  between the sleeper cab  18  and the cargo trailer  14  is left unoccupied. However, referring to FIG. 2, the extendable section  22  of the sleeper cab  18  is shown in a deployed configuration. When in the deployed configuration, the extendable section  22  of the sleeper cab  18  now extends into the articulation zone  20 .  
         [0021]    The articulation zone  20  between the sleeper cab  18  and the cargo trailer  14  need only be left empty when the tractor-trailer  10  is being driven. When the tractor-trailer  10  is being driven, the driver is in the driver cab  16 , not in the sleeper cab  18 . However, when a driver parks the tractor-trailer  10  to rest, the articulation zone  20  between the sleeper cab  18  and the cargo trailer  14  is unutilized space. Consequently, the extendable section  22  can be moved into its deployed configuration, as is shown in FIG. 2.  
         [0022]    Referring to FIG. 3, it can be seen that within the sleeper cab  18 , there may be a toilet, a sink or other objects neatly arranged in the confined space. The extendable section  22  extends from the rear wall of the sleeper cab  18  toward the cargo trailer  14 . In the shown embodiment, the extendable section  22  has a height H1 that is less than the height of the entire sleeper cab  18 . Accordingly when the extendable section  22  is moved into its deployed position, a space exists under the extendable section  22  in the articulation zone  20 . In many models of tractor-trailer trucks, pneumatic couplings, pneumatic hoses and electrical cables interconnect the tractor-trailer truck  12  to the brakes and lights of the cargo trailer  14 . These hoses and cables  26  extend into the articulation zone  20  from the middle of the sleeper cab  18 . By having the extendable section  22  extend into the articulation zone  20  only from the top half of the sleeper cab  18 , the extendable section  22  does not interfere with the hoses and cables  26 .  
         [0023]    In the rear wall  21  of the sleeper cab  18 , there is an opening  23 . The opening  23  is covered by a door  25 . The door  25  is hinged at the bottom. Accordingly, the door  25  can rotate about its hinge from a vertical orientation to a horizontal orientation. When the door  25  is in its vertical position, the door  25  covers the opening  23  in the rear wall  21 . However, when the door  25  is rotated down into its horizontal orientation, the door  25  extends horizontally behind the rear wall  21  of the sleeper cab  18 .  
         [0024]    The extendable section  22  is comprised of the door  25  and a shell  27  that encloses the area over the door  25  when the door is in its horizontal orientation. In the shown embodiment, the shell  27  is a rigid four-sided structure that surrounds the exposed sides of the top of the door  25 . The shell  27  and the door  25  combine to produce a secondary enclosure that is only accessible from the inside of the sleeper cab  18 .  
         [0025]    The space added to the sleeper cab  18  that is made by moving the extendable section  22  into its deployed configuration can be used for any purpose. However, the space added by the deployment of the extendable section  22  is well suited for containing a sleeping bunk  28 . In the embodiment of FIG. 3, it can be seen that a bunk  28  can be pivotally mounted to the interior of the door  25 . When the extendable section  22  is deployed, the bunk  28  folds into the horizontal with the door  25  so that it can be utilized. Since the bunk  28  is located in the space added by the deployment of the extendable section  22 , the presence of the bunk  28  does not interfere with the toilet or any other item contained within the sleeper cab  18 .  
         [0026]    Since, the exterior of the extendable section  22  will be exposed to the elements, it will be understood that weather stripping  29  is used at the joints between the extendable section  22  and the main body of the sleeper cab  18 . The weather stripping  29  prevents rain from seeping through the joints and entering the sleeper cab  18 .  
         [0027]    Referring to FIG. 4, it can be seen that when the extendable section  22  is deployed into the articulation zone  20 , the extendable section  22  forms a cantilevered structure that is supported only by its attachment to the sleeper cab  18 . To support the weight of a person sleeping within the extendable section  22 , supports are provided. There are many supporting structures that can be used. In the embodiment of FIG. 4, two types of supporting structures are shown. One type of supporting structure that can be used includes sliding rail assemblies  30 . The sliding rail assemblies  30  are much like the rails used on the sides of a cabinet draw. The rail assemblies  30  include an external rail  32  that is bolted to the walls of the sleeper cab  18 . A sliding rail  34  passes into the external rail  32  and may contain wheels  35  so that the sliding rail  34  can move freely along the inside of the external rail  32 . The slider rail  34  is rigidly affixed to the structure of the extendable section  22 , thereby providing support to the extendable section  22 .  
         [0028]    A second type of support structure shown in FIG. 4 includes support brackets  38 . The support brackets  38  support the bottom of the extendable section  22  when the extendable section  22  is deployed. The support brackets  38  may be connected to the bottom of the extendable section  22  with a hinged joint. This allows the support brackets  38  to fold away and fall into place when the extendable section  22  is deployed. Alternatively, the support brackets  38  can be attached to the rear of the sleeper cab  18  and can rotate out into position when needed. In yet another embodiment, the support brackets  38  can be removable elements that are set in place by the driver before the extendable section  22  is deployed.  
         [0029]    In the embodiment of FIG. 4, it can be seen that the extendable section  22  includes the use of a rigid shell  27  that encapsulates the space over the door  25 . Such an embodiment is preferred for use in cold or-inclement weather. However, a fabric or mesh structure can alternatively be used. Referring to FIG. 5, it can be seen that flexible tent walls  42  are provided for the sides and top of the shell  40 . A tent pole  44  can be used to support the top corner of the: tent&#39;s structure, to form the shell  40 . Support wires  46  can be used to support the door  45  when it is deployed horizontally.  
         [0030]    Such an embodiment is very inexpensive to manufacture and can be retroactively added to existing sleeper cabs. However, since this embodiment has only fabric walls, a driver would only use it during warm, fair weather conditions.  
         [0031]    It will be understood that the system and method of the present invention described and illustrated are merely exemplary and a person skilled in the art can make many variations to the shown embodiment. All such alternate embodiments and modifications are intended to be included within the scope of the present invention as defined below in the claims.