Abstract:
An upper rail configuration for mounting a wheeled trolley assembly for mounting curtains on a curtain side trailer has removable and replaceable inserts which have a configuration a complementary to the upper rail configuration. A top portion of each insert fits into a slot in the upper rail and the bottom of each insert rests on a shelf of the upper rail. Once worn, these inserts can be replaced in the field at a fraction of the cost of completely new upper rail.

Description:
TECHNICAL FIELD 
     This invention relates generally to curtain side trailers and more particularly to an upper rail insert for use in a curtain side trailer. 
     BACKGROUND 
     Curtains for curtain side trailers are opened and closed by attaching the curtains to a trolley with rollers to a top rail on the trailer. Because these curtains are moved often, eventually the rails upon which the rollers roll become worn and must be replaced or repaired. 
     One solution to the aforementioned repair process has been to put a replaceable steel flange over the worn surface. These upper rail inserts appear to be held in by the rollers themselves. While this solution works to some extent, shifting of these prior art upper rail inserts will cause them to wear prematurely. Furthermore these upper rail inserts are not easily replaced in the field. Accordingly, there is a need for a better way to hold upper rail inserts in place. 
     SUMMARY OF THE INVENTION 
     An upper rail configuration for mounting a wheeled trolley assembly for mounting curtains on a curtain side trailer has removable and replaceable inserts which have a configuration complementary to the upper rail configuration. A top portion of each insert fits into a slot in the upper rail and the bottom of each insert rests on a shelf of the upper rail. A projection on the bottom of each of the upper rail inserts fits into a complementary groove in the shelf to further prevent shifting of the insert with respect to the upper rail. Once worn, the inserts can be replaced in the field at a fraction of the cost of completely new upper rail. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above needs are at least partially met through provision of the apparatus described in the following detailed description, particularly when studied in conjunction with the drawings, wherein: 
         FIG. 1  is a perspective view of a prior art curtain side trailer upon which the present invention can be used; 
         FIG. 1A  is a cross sectional view through the upper beam of a prior art curtain side trailer; 
         FIG. 2  is a cross sectional view through the upper beam of a prior art curtain side trailer, similar to  FIG. 1A , but of the present invention; 
         FIG. 3  is an enlarged cross sectional view that is within the circle  3  of  FIG. 2 ; 
         FIG. 4  is a cross sectional view showing just the left side portion of what is shown in  FIG. 2 , showing one way in which the insert of the present invention can be positioned just prior to being moved to the installed  FIG. 5  position; 
         FIG. 5  is a cross sectional view like  FIG. 4  showing just the left side portion of what is shown in  FIG. 2 , but showing the installed position of the insert of the present invention after it is moved from the  FIG. 4  position; 
         FIG. 6  is an exploded perspective view showing another way in which the insert of the present invention can be positioned just prior to being moved to the installed position of  FIGS. 2 and 3 ; and 
         FIG. 7  is a perspective view of the insert of  FIGS. 2-6  flipped over from the  FIG. 6  position to show a projection on the bottom thereof that fits into a groove formed in the upper rail. 
     
    
    
     Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. Certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. The terms and expressions used herein have the ordinary technical meaning as is accorded to such terms and expressions by persons skilled in the technical field as set forth above except where different specific meanings have otherwise been set forth herein. 
     DETAILED DESCRIPTION 
     The present invention relates to an improvement to a curtain side trailer of the type shown in U.S. Pat. No. 7,578,539 to Acker, which patent is incorporated herein by reference in its entirety. It is to be understood that for the purposes of this invention, the upper rails of curtain side trailers can be the same as those for curtain side truck bodies. Accordingly the claimed invention is intended to cover structures for both curtain side trailers and curtain side truck bodies. 
     Referring now to the drawings wherein like numerals designate identical or corresponding parts throughout the several views,  FIG. 1  shows a curtain side semi trailer  1  with intermediary pillars  2  that are connected from the floor  3   f  to the trailer roof  4 . The pillars  2  are connected at their upper end to a rail or upper frame  5  and at their lower end to lower frame  3 . 
       FIG. 1A  is a cross-section of the upper frame  5  showing rollers  24  rotatably mounted to a curtain bracket  26 , the rollers  24  rolling in a track formed by ledges  15  formed on the upper frame  5 . 
     Looking now to  FIG. 2 , a trolley wheel assembly  127  is disposed on the tracks  125  of the upper frame  115  to permit the trolley wheel assembly  127  to move along the tracks  125 . 
     The tracks  125  are formed by first and second removable elongated L-shaped members  150   a / 150   b  wedged into complementary structure on the upper frame  115  shown best in  FIGS. 4-7 , which show an upper horizontal wall  115   h , a first vertical wall  115   vwa  extending downwardly from the upper horizontal wall and a second vertical wall  115   vwb  extending downwardly from the upper horizontal wall  115   h , the second vertical wall  115   vwb  being spaced from the first vertical wall  115   vwa.    
     A first ledge  115   dga  disposed on the first vertical wall  115   vwa  is spaced a first distance below the upper horizontal wall  115   h , the first ledge  115   dga  extending towards the second vertical wall  115   vwb , a first slot  115   da  disposed in the first vertical wall  115   vwa  above the first ledge  115   dga.    
     A second ledge  115   dgb  is disposed on the second vertical wall  115   vwb  spaced by said first distance below the upper horizontal wall  115   h , the second ledge  115   dgb  extending towards the first vertical wall  115   vwa . A second slot  115   db  disposed in the second vertical wall  115   vwb  above the second ledge  115   dgb.    
     A first removable elongated L-shaped member  150   a  has a top portion  150   ta  disposed in the first slot  115   da  of the first vertical wall  115   vwa  and a lower horizontal portion  150   hpa  resting on an upper portion  115   dga  of the first ledge  115   dga.    
     The second removable elongated L-shaped member  150   b  has a top portion  150   tb  disposed in the second slot  115   sb  of the second vertical wall  115   vwb  and a lower horizontal portion  150   hpb  resting on an upper portion of the second ledge  115   dgb . The elongated L-shaped members  150   a / 150   b  are preferably formed of anodized (hardened) aluminum to dramatically extend the life of the upper frame aluminum rails  115 . Once worn, they can be replaced in the field at a fraction of the cost of completely new upper rail. 
     A curtain bracket  126  is disposed between the first and second L-shaped members  150   a / 150   b  and the curtain bracket  126  has two rollers  124  ( FIG. 6 ) rotatably attached to the curtain bracket  126  about a first axis  124   a  and two more rollers  124  ( FIG. 6 ) rotatably attached to the curtain bracket  126  about a second axis  124   b . The left-most roller shown in  FIGS. 2 and 6  are disposed on top of the lower horizontal portion  150   hpa  of the first removable elongated L-shaped member  150   a  and disposed below the upper horizontal wall  115   h . The other two rollers  124 , on the right hand side as viewed in  FIGS. 2 and 6 , are rotatably attached to the curtain bracket  126 . These other two rollers  124  are disposed on top of the lower horizontal portion  150   hpb  of the second removable elongated L-shaped member  150   b  and disposed below the upper horizontal wall  115   h.    
     A first depression  115   da  is disposed in an upper surface of the first ledge  115   dga  and a first projection  115   pa  projects from the bottom of the lower horizontal portion  115   hpa  of the first removable elongated L-shaped member  115   a  extending into the first depression  115   da  ( FIG. 4 ) in the upper surface of the first ledge  115   dga.    
     A second depression (like  115   da ) is disposed in an upper surface of the second ledge  115   dgb . A second projection  115   pb  projects from the bottom of the lower horizontal portion  115   hpb  of the second removable elongated L-shaped member  115   b , extending into the first depression ( FIG. 6 ) in the upper surface of the second ledge  115   dgb.    
     In operation, one way to install the first and second removable elongated L-shaped members  150   a / 150   b  is shown in  FIG. 6  by sliding the first and second removable elongated L-shaped members  150   a / 150   b  in the direction of the arrows in  FIG. 6 . Then the trolley assembly  127  is rolled into place by moving the trolley assembly  127  in the direction of the arrow shown in  FIG. 6 . When the first and second removable elongated L-shaped members  150   a / 150   b  become too worn, they can easily be replaced by reversing this process to remove them and then inserting new first and second removable elongated L-shaped members  150   a / 150   b.    
     An alternate way of installing the first and second removable elongated L-shaped members  150   a / 150   b  is shown in  FIGS. 4 and 5 , by first placing the first removable elongated L-shaped members  150   a  in a position so the top  150   ta  can be moved into the slot  115   sa  and then pivoting the member  150  from the  FIG. 4  to the  FIG. 5  position so that the projection  150   pa  fits into the depression/groove  115   da  in ledge  115   dga . Of course the procedure is essentially the same for installing the second removable elongated L-shaped member  150   b  in place on the other side. And removal of the first and second removable elongated L-shaped members  150   a / 150   b  is to essentially reverse the process, going first from the  FIG. 5  position of the first removable elongated L-shaped members  150   a  to the  FIG. 4  position of the first removable elongated L-shaped members  150   a.    
       FIGS. 2 and 6  show an optional curtain seal  129  which is typically made of a plastic elastomeric material. 
     Those skilled in the art will recognize that a wide variety of modifications, alterations, and combinations can be made with respect to the above described embodiments without departing from the spirit and scope of the invention, and that such modifications, alterations, and combinations are to be viewed as being within the ambit of the inventive concept as expressed by the attached claims.