BACKGROUND OF THE INVENTION 
   This invention relates to covers that enclose the bed area of a pickup truck. Tonneau covers are usually hard or soft covers that enclose bed of a pickup truck and protect that area from rain, snow and other weather elements. 
   SUMMARY OF THE INVENTION 
   The present invention is a pickup-truck bed cover which incorporates elements of both low-profile tonneau covers and solid-wall canopies. This convertible design transforms from several inches flat to a full height canopy in seconds—all while providing solid-wall, insulated security in either the expanded or collapsed position. In addition, the cover is designed to be safely driven down the road while either expanded or collapsed. 
   In the collapsed position, this cover provides outstanding driver visibility and a sleek low-profile appearance. It is preferably constructed of aluminum tread-plate, which provides a durable and attractive finish that compliments trucks of any color. Although the cover is only a few inches high in the collapsed position, in the expanded position it provides nearly four feet of interior height and cargo capacity superior to that of many fixed canopies. 
   There are five main components to the design: the frame, top cover, right sidewall, left sidewall and rear door. The sidewalls and rear door stow inside and under the top cover. The top cover pivots open which allows access to un-stow the rear door. The sides then pivot up to form the canopy. This design maintains the ability to store cargo below the bed sill height in either configuration, with access through the truck rear tailgate or canopy rear door. 
   The cover is generally rectangular in shape. It is several inches wider than the open bed of the pickup-truck. A preferably “U” shaped frame is affixed to the truck bed—along both sides and across the front of the bed. One half of a hinge rests along each of these three sides. The hinge along the forward edge of the frame attaches to the forward edge of the top cover and allows the cover to pivot open. Hinges along the left and right sides of the frame are attached to the left and right sidewall panels and allow each sidewall to pivot to a vertical position. 
   The left and right sides of the top cover have straight and level lower edges which are bent 90 degrees outward to rest on the upper edges of the truck bed. The top of the top cover is flat and level, parallel to the lower edges of the top cover sides. There is a slope at the front of the top cover beginning at the lower forward corner progressing upward and aft. This slope allows the cover to pivot open without intersecting the cab or rear window of the truck. The slope is of such an angle that it is generally vertical when the cover is in the expanded position. 
   On the aft portion of the top cover, there is another slope. This slope tapers from the upper surface of the top cover aft and downward to the rear edge of the cover. The slope is of such an angle that it is directly horizontal in the expanded position. This slope allows the aft portion of the cover to taper for better driver visibility and aerodynamics, yet provides a flat and level design element when expanded. 
   Two gas-filled lift struts are positioned inside the top cover. One end of each strut is attached near the forward side of the frame, and the other end is attached to the inner surface of the top cover side. These struts are located in such a position and geometry as to assist in raising open the cover and holding it up. The sidewalls are designed with the lift struts positioned between the inner panels of the sidewalls, and the sides of the top cover, which allows the lift struts to be hidden from view (from both the inside and the outside) when the sidewalls are expanded. 
   Attached to the upper surface of the top cover are two tiedown rails. These provide several hardpoints to secure oversize items carried on top of the cover. The bolts that attach these rails to the top cover also bolt through to the internal bracing in the roof of the top cover. 
   All components of this design overlap each other in both the expanded and collapsed positions to keep water out. A piece of flashing is located at the forward edge of each rail which prevents water from entering near the forward edge of the sides. Additional water intrusion is prevented by a series of seals. This overlapping component design, however, provide an inherent deterrent to leaks well beyond the dependence on seals. 


   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a rear perspective view of the convertible pickup canopy of the present invention, the convertible pickup canopy shown in an expanded condition and attached to a bed of a pickup truck; 
       FIG. 1A  is a rear perspective view of a frame of the convertible pickup canopy, the frame coupled to rails of a truck bed; 
       FIG. 2  is a rear perspective view of the convertible pickup canopy of the present invention, the convertible pickup canopy shown in an expanded condition, with a rear access door opened; 
       FIG. 3  is a rear perspective view of the convertible pickup canopy of the present invention, the convertible pickup canopy shown in an expanded condition, with a rear access door opened, and a left side panel collapsed; 
       FIG. 4  is a rear perspective view of the convertible pickup canopy of the present invention, the convertible pickup canopy shown in an expanded condition, with a rear access door opened, and the left and a right side panel collapsed; 
       FIG. 5  is a rear perspective view of the convertible pickup canopy of the present invention, the convertible pickup canopy shown in an expanded condition, with a rear access door stowed, and the left and a right side panel collapsed; 
       FIG. 6  is a rear perspective view of the convertible pickup canopy of the present invention, the convertible pickup canopy shown in a collapsed condition; 
       FIG. 7  is a rear perspective view of the convertible pickup canopy of the present invention, the convertible pickup canopy shown in a collapsed condition and the top cover removed. 
       FIG. 8  is a perspective view of interior components of the convertible pickup canopy. 
   


   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims. 
   Referring now to  FIG. 1 , is a rear perspective view of a convertible pickup canopy  10  of the present invention is shown, the convertible pickup canopy  10  shown in an expanded condition and attached to a bed of a pickup truck. 
   There are five main components to the design: the frame  11  (discussed with reference to  FIG. 1A  below), top cover  12 , right sidewall  24 , left sidewall  24  and rear door  28 . The sidewalls  24  and rear door  28  stow inside and under the top cover  12  as will be described later. The top cover  12  pivots open which allows access to un-stow the rear door  28  as will be described later. The sides  24  then pivot up to form the canopy. This design maintains the ability to store cargo below the bed sill height in either configuration, with access through the truck rear tailgate or canopy rear door. 
   The top cover  12  is preferably equipped with tiedown rails  14 . The tiedown rails  14  provide several hardpoints to secure oversize items carried on top of the cover. Bolts (not shown) attach tiedown rails  14  to the top cover  12 . 
   A plurality of windows  16  are optionally provided on the top cover  12 , and sidewalls  24 . Handles  18  are also provided on various locations, preferably the rear door  28  and a rear portion  38  of the top cover  12  for movement, lifting or lowering of those parts. 
   Left and right sides  26  of the top cover  12  have preferably straight and level lower edges which are bent 90 degrees outward to rest on rails  2  of the truck bed. The top portion  12 B of the top cover  12  is preferably flat and level, parallel to the lower edges of the top cover sides  26 . There is preferably a slope  12 C at the front of the top cover  12  beginning at the lower forward corner progressing upward and aft. This slope  12 C allows the cover to pivot open without intersecting the cab or rear window of the truck. The slope  12 C is preferably of such an angle that it is directly vertical when the cover  10  is in the expanded position. 
   On the aft portion of the top cover  12 , there is another slope  12 A. This slope  12 A tapers from top portion  12 B of the top cover  12  aft and downward to the rear edge of the cover  10 . The slope  12 A is of such an angle that it is preferably horizontal in the raised position. This slope  12 A allows the aft portion of the cover to taper for better driver visibility and aerodynamics, yet provides a flat and level design element when raised. 
   Two preferably gas-filled lift struts  22  (only one is visible in  FIG. 1 ) are positioned inside the top cover  12 . One end of each strut  22  is attached near the forward side of the frame  11 , and the other end is attached to inner surfaces of the top cover sides  26 . These struts  22  are located in such a position and geometry as to assist in raising open the cover  10  and holding it up. The sidewalls  26  are designed with the lift struts  22  positioned between the inner panels of the sidewalls  26 , and the sides of the top cover  12 , which allows the lift struts  22  to be hidden from view (from both the inside and the outside) when the sidewalls  24  are raised. 
   Referring now to  FIG. 1A , a rear perspective view of the frame  11  of the convertible pickup canopy  10  is shown, the frame  11  coupled to rails  2  of a truck bed. The frame  11  is affixed to the truck bed—along both side rails  2  and across the front rail  2  of the bed. Half hinges  30  (an example shown in detail in  FIG. 8 ) rest along each of the three sides of the frame  11 . The hinge  30  along the forward edge of the frame attaches to the forward edge of the top cover  12  and allows the cover to pivot open. Hinges  30  along the left and right sides of the frame are attached to the left and right sidewall panels and allow each sidewall  24  to pivot to a vertical position for placing the cover  10  in its expanded condition. Flashings  20  are provided coupled to the frame  11  and providing a surface for struts  22  to affix to, and to prevent water from entering the truck bed near the forward edge of the frame  11 . 
   Referring now to  FIG. 2 , a rear perspective view of the convertible pickup canopy  10  of the present invention is shown, the convertible pickup canopy  10  shown in an expanded condition, with a rear access door  28  opened. As can be seen from this view, two additional struts  22  are coupled between the sidewalls  24  and a top portion of the rear access door  28 , allowing and assisting the rear access door  28  to pivot and remain opened if desired. Preferably, the portion of the struts  22  that attach to the access door  28  are removably coupled with the sidewalls  24 , to allow the canopy  10  to enter its collapsed condition, as will be described later. 
     FIGS. 3-7  demonstrate the conversion of the canopy  10  from its expanded to its collapsed condition. 
   Referring now to  FIG. 3 , a rear perspective view of the convertible pickup canopy  10  of the present invention is shown, the convertible pickup canopy  10  shown in an expanded condition, with the rear access door opened  28 . It can be seen that the strut  22  attached to the left sidewall  24  has been detached from the left sidewall  24 , allowing the left sidewall  24  to rotate about hinge  30  (example of hinge  30  shown in  FIG. 8 ) into a substantially horizontal position hovering over the bed of the pickup truck. 
   From this view, it is evident that the sidewalls  24  are shaped complimentary along their top edge to the profile of the top cover  12 , notably where the surfaces  12 A and  12 B of the top cover  12  are slanted. Similarly, the profile of the sidewalls  24  are shaped complimentary to the two-plane profile of the rear access panel  28 . This allows for a tight fit and aids structural stability of the convertible pickup canopy  10 . 
   Referring now to  FIG. 4  both the left and a right side panels have been collapsed by detaching struts  22  from the sidewalls  24 . The sidewalls  24  now both lie in their collapsed condition over the bed of the truck. 
   Referring now to  FIG. 5 , the rear door  28  has been rotated about a hinge (not shown) and tucked under the top cover  12 . It is noted also that the shape of the rear door  28  is complimentary with the profile of the top cover  12  such that when the top cover  12  becomes lowered, the rear door  28  will be sandwiched between the sidewalls  24 , already lying in their substantially horizontal collapsed condition and the top cover  12 . 
   Referring now to  FIG. 6 , after collapsing the sidewalls  24  and the rear door  28 , the top cover  12  can be pulled downward, rotating about struts  22  and placing the convertible pickup canopy  10  in its fully collapsed condition. 
   Referring now to  FIG. 7  is a rear perspective view of the convertible pickup canopy  10  of the present invention, the convertible pickup canopy  10  shown in a collapsed condition and the top cover removed. Latching mechanisms (such as shown in  FIG. 8 ) can be provided to ensure that the top cover  12  remains collapsed when intended. 
   Referring now to  FIG. 8  is a perspective view of interior components of the convertible pickup canopy  10 . This view shows the canopy  10  in a position as in  FIG. 2 , with the canopy  10  in an expanded condition, with sidewall  24  shown vertical and top cover  12  secured thereto. A latch  57  is provided to secure sidewalls  24  with the top cover  12  with sidewall  24  in the expanded condition. The latch  57  is detached for placing the canopy  10  in the collapsed condition. Also shown is strut  22  which is coupled between rear door  28  and sidewall  24  as shown in  FIG. 2 . As can be seen, hinge  30  allows rear door  28  to pivot open as shown in  FIG. 2 . 
   The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
A convertible pickup canopy is disclosed, the canopy having left and right sidewalls hingedly coupled with a frame member. The frame member is coupled with rails of the bed of a pickup truck, and allow the sidewalls and a rear door to expand to support a top cover, and to collapse to allow the top cover to travel in a lower profile.