Abstract:
A roof for a sleeper compartment truck is built from a plurality of pieces of manageable size while minimizing the required labor and waste of material required for construction.

Description:
BACKGROUND OF THE INVENTION 
   1. Technical Field 
   The invention relates to motor vehicle assembly and more particularly to assembly of a roof for a sleeper compartment truck from a plurality of pieces of manageable size while minimizing the required labor and waste of material. 
   2. Description of the Problem 
   Typical roof designs for truck sleeper compartments call for a glass reinforced plastic shell made of one or a plurality of pieces. The shell has been separately reinforced, typically with reinforcements made of the same material as the shell. The reinforcements are required to meet strength and rollover protection requirements. Generally, increasing the number of components increases tooling costs, total cost for components and fabrication time. Construction of the shell from a single piece of glass reinforced plastic limits the number of suppliers and provides a difficult to handle component. 
   SUMMARY OF THE INVENTION 
   According to the invention there is provided a roof for a motor vehicle cab. The roof comprises front and aft sections. Each section of the sections having an exterior face and an interior face and at least a first, substantially straight, end edge, with first end edges being disposed in a side-by-side relationship. A C-section trough is formed along the front edge of the aft roof shell section. The C-section is depressed with respect to and open in the direction of the face for the aft roof shell section for application to the interior face of the front roof section which overlays it upon assembly. The C-section trough is disposed adjacent the interior face of the forward roof shell section inwardly from the front edge thereof to form with the second roof shell section a box section reinforcement beam running from side to side of the motor vehicle. Additional reinforcement beams are formed by direct application of trough like reinforcements against the interior surfaces of the major exterior pieces of the shell. 
   Additional effects, features and advantages will be apparent in the written description that follows. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself however, as well as a preferred mode of use, further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: 
       FIG. 1  is a perspective view of a sleeper cab shell for a truck. 
       FIG. 2  is a perspective view of a outer roof shell for the sleeper cab shell of  FIG. 1 . 
       FIG. 3  is a perspective view of the forward section of the outer roof shell of  FIG. 2 . 
       FIG. 4  is a perspective view of the aft section of the outer roof shell of  FIG. 2 . 
       FIG. 5  is an exploded view of the outer roof shell. 
       FIG. 6  is a plan view from inside of the outer roof shell toward the back wall to the outer roof shell. 
       FIG. 7  is a rear plan view of the outer roof shell. 
       FIG. 8  is a front plan view of the outer roof shell. 
       FIG. 9  is a cross sectional view of the outer roof shell taken along section line  9 — 9  in  FIG. 8 . 
       FIG. 10  is a cross sectional view of a joint between the aft and forward outer roof shell sections. 
       FIG. 11  is a cross sectional view taken along section line  11 — 11  of  FIG. 8 . 
       FIG. 12  is a cross sectional view taken along section line  12 — 12  of  FIG. 9 . 
       FIG. 13  is a bottom plan view of the inside of the roof shell. 
       FIG. 14  is a cross sectional view taken along section line  14  of  FIG. 13 . 
       FIG. 15  is a cross sectional view taken along section line  15 — 15  of  FIG. 13 . 
       FIG. 16  is a bottom plan view of the aft section of a other roof shell. 
       FIG. 17  is a cross sectional view taken along section line  17 — 17  of  FIG. 16 . 
       FIG. 18  is a cross sectional view taken from the area marked  18  in  FIG. 17 . 
       FIG. 19  is an elevation of the aft wall from the inside of the outer roof shell. 
       FIG. 20  is a cross sectional view taken along section lines  20 — 20  of  FIG. 19 . 
       FIG. 21  is a perspective view in partial section illustrating mating of a roof shell to the framework of a cab shell. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIG. 1  a sleeper cab shell  10  for a truck comprises an outer roof shell  12  and a main body shell and frame  14 . As illustrated below, outer roof shell  12  rests on and is bonded to main body shell and frame  14 . Main body shell and frame  14  comprise right and left sidewalls  18  and  16 , a back wall  22 , a forward frame  20  and a floor  24 . 
   Outer roof shell  12  is a multi-piece body section, and is made from glass reinforced plastic sections which are joined by bonding using an adhesive. Such adhesives and bonding techniques are well known in the art and are not described in detail here.  FIG. 2  illustrates the location of the several pieces which form the outer roof shell. These include an aft roof section  26 , a forward roof section  28 , a left side section  30 , a left side leading section  32  and a right side leading section  34 . A right side section and back wall are not visible in the figure. Forward roof section  28  tapers to a point at its forward most point to match the aerodynamic shaping of the paired left side and right side leading sections  32 ,  34 . 
   In  FIG. 3  it may be seen that the forward roof section  28  of outer roof shell  12  is a semi-circular piece resting on two bowed forward leading sections  32 ,  34 , which together form a partial assembly of the outer roof shell  12 . The bowing of the mated leading sections  32 ,  34  tracks the curvature of the leading edge of forward roof section  28  to produce an aerodynamic shape. 
     FIG. 4  illustrates aspects of the configuration of an aft roof assembly  25  including aft roof section  26 , left side section  30  and right side section  31 . Aft roof section  26  as assembled provides a reinforcement channel  36  formed along a forward edge  452  of the aft roof section  26  and left and right side sections  31 . Reinforcement channel  36  is a C-channel positioned to support from below the forward roof section  28  from inside of its trailing edge  327 . Reinforcement channel  36  runs from side to side, perpendicular to the direction of travel of the vehicle. Reinforcement channel  36  includes troughs  42  (formed in aft roof section  26 ) and  52  (formed in left side section  30 ). Running the lengths of troughs  42  and  52  are strips  38 ,  40 ,  48  and  50  (as well as similar strips for right side section  31 ). Strips  38 ,  40 ,  48  and  50  are intended to be brought into contact with the under, interior surfaces  128  (See  FIG. 13 ) of forward roof section  28  and left side leading section  32 . Conventional adhesives used with glass reinforced plastics are used between strips  38 ,  40 ,  48  and  50  and the forward roof section  28  and left side leading section  32  which bond the elements into what is essentially a joint piece. Combined with the forward elements, reinforcement channel  36  becomes a box frame element  500  (See  FIGS. 9 ,  13 ) reinforcing the joint roof structure which runs from side to side of the vehicle just behind the vehicle&#39;s doors. 
     FIG. 5  is an exploded view of the outer roof shell  12 . Outer roof shell  12  comprises forward and aft roof sections  28 ,  26 . Shell  12  further comprises left and right leading side sections  32  and  34  as well as trailing left and right side sections  30 ,  31 . A back wall  56  fits between the trailing edges of left and right side sections  30 ,  31 . Supplemental reinforcement sections underlie the roof sections and side sections, including an aft supplemental roof reinforcement section  54 , back wall reinforcement sections  62  and left and right side supplemental reinforcement sections  58  and  60 . Supplemental reinforcement sections are essentially pieces with trough like cross sectional portions. Applied by adhesive to inside surfaces of exterior shell elements, they combine with those elements to form box-type beam supports. 
     FIG. 6  is a plan view from inside of the outer roof shell  12  illustrating positioning of back wall reinforcements  62  against the back wall element  56 . Back wall reinforcement sections  62  include five vertical channel sections  162 ,  262 ,  362 ,  462  and  562 . All of the channel sections are C-channels with bordering strips allowing application and bonding to the inner wall of the back wall  56  to form a box type beam support. 
     FIGS. 7 and 8  illustrate outer roof shell  12  front and back, highlighting the front end streamlining of the shell and indicating the location of a seem  70  between the forward and aft roof sections  28 ,  26 , on the one hand, and the back wall  56  and right and left side leading sections  34 ,  32 .  FIG. 9  shows the location of a side reinforcement section  60  adhering to the inside face of right side section  31 . 
     FIGS. 10–12  are cross sections illustrating joints between several sections of outer roof shell  12 . In  FIG. 10  the overlap of forward roof shell section  28  where it contacts and rests on strip  38  between trough  42  and the main body of aft roof shell section  26  is illustrated. In  FIG. 11  the juncture of leading side sections  32  and  34  is closed by overlays  74  and  76 . An indentation  72  in the outside face of section  34  is partially covered by overlay  76  forming a pocket into which a hooked end of overlay  74  fits. The effect is to produce a leak proof fitting.  FIG. 12  illustrates that aft roof section  26  rests on the upper edge of side section  31 . 
     FIG. 13  illustrates fitting of reinforcement sections  54  and  81  to the lower interior surfaces  126 ,  128  of aft roof section  26  and forward roof section  28 , respectively. Reinforcement sections  54  and  81  are open channel sections, applied with the channel side open to the surface of the section to be reinforced so that upon bonding, a box section beam is formed from these walls of the reinforcement element and a fourth wall from the reinforced shell element.  FIG. 14  illustrates reinforcement of the base of rear wall  56  where it turns inwardly to form a flange for support on cab  14 . Reinforcement is affected by an open, flattened W-shaped member applied by its bottom face against the main portion of the interior surface of back  56  and the turned in flange. The exterior arms of the “W” are joined to the sub-sections back  56  and the interior arms form with those sub-sections a box section reinforcement member.  FIG. 15  illustrates the overlap of forward roof section  28  over leading left side section  32  along joint  70 . 
     FIG. 16  is a bottom plan view of the aft section of outer roof shell  12  illustrating a reinforcement piece  57  which is adjusted in size to fit a shortened aft roof section.  FIGS. 17 and 18  illustrate formation of joint  70  from an overlap of aft roof section  26  over right side section  31 . 
     FIGS. 20 and 21  illustrate joint  70  of aft roof section and back wall  56  and reinforcement of the area using a flattened S-shaped member  90  which is fitted to brace the sections against one another. 
   The invention provides a roof shell for a sleeper cab which is simple to construct from elements which are in turn easily fabricated. 
   While the invention is shown in only one of its forms, it is not thus limited but is susceptible to various changes and modifications without departing from the spirit and scope of the invention.