Abstract:
The present invention provides an improved sliding curtain wall system for selectively closing an opening in a side of a covered trailer in which a plurality of elongate support members are slidably mounted to the side of the trailer to support several pieces of tarpaulin therebetween. Such a system allows the curtain wall to be easily opened and closed by sliding the support members along the length of the opening in the side of the covered trailer. Such a system also eliminates the need for straps and buckles to provide tension to the tarpaulin that forms the curtain.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims the benefit of U.S. Provisional Patent Application No. 61/819,177, filed May 3, 2013, the contents of which are hereby incorporated by reference in its entirety. 
    
    
     FIELD OF INVENTION 
     The invention relates to enclosed vehicle trailers, and in particular, enclosed trailers having an open side that is selectable closable with a tarpaulin. 
     BACKGROUND 
     In the field of enclosed trailers, for example trailers for trucks having enclosed interior spaces, as opposed to flat bed trailers or trailers having side walls but open tops, several different means of opening and closing the trailer to gain access to the enclosed interior space are known. One of such means is a sliding curtain wall, in which a tarpaulin or other similar sheet of material can be selectively drawn across an opening in a side of the trailer to selectively open or close the trailer. 
     Currently, it is known to make such sliding curtain walls using a single tarpaulin extending across the entire opening in the side of the trailer. The single tarpaulin is drawn taught and held in a closed position using a series of straps attached to the tarpaulin, which are pulled tight and held in place using a series of overcenter buckles; the straps and buckles ensure the tarpaulin remains tensioned vertically from top to bottom at all times. Such an arrangement is disadvantageous for several reasons. By way of example, the opening and closing of the sliding curtain wall becomes labour-intensive and time consuming using such a closure arrangement. Typically, truck operators will only tension every second buckle for short trip deliveries due to laziness. This leads to buckles getting damaged or ripped off, as well as damage to the tarpaulin. 
     In view of the foregoing, it is clear that there is a need for an improved sliding curtain wall system, one that can be opened and closed more quickly and easily. 
     SUMMARY OF THE INVENTION 
     The present invention provides an improved sliding curtain wall system for selectively closing an opening in a side of a covered trailer in which a plurality of elongate support members are slidably mounted to the side of the trailer to support several pieces of tarpaulin therebetween. Such a system allows the curtain wall to be easily opened and closed by sliding the support members along the length of the opening in the side of the covered trailer. Such a system also eliminates the need for straps and buckles to provide tension to the tarpaulin that forms the curtain. 
     In one embodiment of the invention, there is provided an enclosed trailer having a selectively openable side, comprising at least one opening in at least one side thereof, a plurality of elongate support members, each of said elongate support members extending from a first end slidably attached to the enclosed trailer at a top of the at least one opening, to a second end slidably attached to the enclosed trailer at a bottom of the at least one opening, such that each of the elongate support members can slide along the length of the opening, and at least one tarpaulin mounted to at least two of the elongate support members. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a side view of a truck and trailer having a sliding curtain wall in a closed configuration, according to the present invention. 
         FIG. 2  is a side view of the truck and trailer of  FIG. 1 , with the sliding curtain wall of the present invention in a first open configuration. 
         FIG. 3  is a side view of the truck and trailer of  FIG. 1 , with the sliding curtain wall of the present invention in a second open configuration. 
         FIG. 4  is a front view of a first embodiment of an elongate support member of the sliding curtain wall of the present invention. 
         FIG. 4A  is a top view of the embodiment of the elongate support member of  FIG. 4 . 
         FIG. 5  is a front view of a second embodiment of an elongate support member of the sliding curtain wall of the present invention. 
         FIG. 6  is a sectional view taken along line  6 - 6  of  FIG. 1 . 
         FIG. 7  is a sectional view taken along line  7 - 7  of  FIG. 1 . 
         FIG. 8  is a front view of a portion of a third embodiment of an elongate support member of the sliding curtain wall of the present invention. 
         FIG. 9  is a perspective view of an embodiment of the invention showing an adjustable tarp tensioning plate. 
         FIG. 9A  is a perspective view of the adjustable tarp tensioning plate. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The sliding curtain wall system of the present invention will now be described with reference to particular embodiments thereof, which are illustrated in the drawings.  FIGS. 1, 2 and 3  illustrate a truck and enclosed trailer  100  attached thereto. The trailer  100  has an opening  105  formed along one side thereof. In the illustrated embodiment, the opening  105  comprises a completely open side; that is, the trailer  100  is simply constructed without a side panel on one of its sides. However, it will be understood that the opening  105  can be of any size desired, and can be formed by cutting away a portion of a side of the trailer  100 , in addition to omitting a side panel of the trailer  100 . It also will be understood that the opening  105  can be formed in any side of the trailer  100  (with the obvious exception of the bottom). It will be further understood that the trailer could have two openings, one on either side of the trailer. Such a trailer could be constructed using a front and rear wall and a roof, mounted on a flatbed trailer. 
       FIGS. 1, 2 and 3  also illustrate an embodiment  110  of the sliding curtain wall system of the present invention.  FIG. 1  illustrates the curtain wall  110  in a ‘closed’ position, in which the opening  105  is closed off.  FIGS. 2 and 3  illustrate the curtain wall  110  in two alternative ‘open’ positions in which the interior of the trailer  100  is accessible via the opening  105 . 
     The curtain wall  110  comprises a plurality of elongate support members  120 ,  130  which extend across the width of the opening  105  and are slidably attached to the trailer  100 , such that they may slide up and down the length of the opening  105 . The elongate support members  120 ,  130  may be attached to the trailer  100  in any known manner suitable for allowing the support members  120 ,  130  to slide along the opening  105 . The particular manner in which the illustrated embodiments of the support members  120 ,  130  are slidably attached to the trailer  100  will be described in greater detail below. 
     The elongate support members are arranged in a line along the length of the opening. The support members  130  at the front and back of the line are of a somewhat different design than the remainder of the support members  120 . The differences between these two embodiments of the support member will be discussed in greater detail below. As will be seen, the support member  130  is wider, and has a lower centre of gravity. These properties make it less likely that the support member  130  will tip forward or backward when the support member  130  is pushed or pulled along the length of the opening  105 , causing the support member  130  to jam. It will be understood, however, that identical structures can be used for all elongate support members of the sliding curtain wall  110 , if desired. 
     The curtain wall  110  further comprises a plurality of tarpaulin segments  140 . Each of the tarpaulin segments  140  is affixed at one end to one of the elongate support members  120  (or  130 , as the case may be) and is affixed at an opposing end to another of the elongate support members  120  or  130 ). The tarpaulin segments  140  can be attached to the support members  120  (or  130 ) in any suitable manner. For example, the tarpaulin segments  140  can be attached to the support members  120  (or  130 ) in any suitable manner. An example attachment is described in detail below. Each tarpaulin segment  140  covers substantially all of the space between the support members  120  (or  130 ) to which it is attached. 
     Alternatively, a single tarpaulin can be used that extends across substantially all of the opening  105  in the trailer  100 , and is attached to all of the support members  120 ,  130 . Such attachment can be achieved by any suitable means, for example, by using VELCRO™ hook and loop fastener straps that wrap around the support members  120 ,  130 . 
     In operation, when the sliding curtain wall  110  is closed, the elongate support members  120  and  130  are approximately evenly distributed along the length of the opening  105 . The support member  130  at the front of the line of support members (hereinafter, the “front support member”) is directly adjacent the forward edge of the opening  105 , and the support member  130  at the back of the line of support members (hereinafter, the “rear support member”) is directly adjacent the rearward edge of the opening  105 . In this configuration (shown in  FIG. 1 ), the tarpaulin segments  140  extend across substantially all of the opening  105 , thus closing the opening  105 . 
     To open the trailer  100 , the rear support member  130  can be slid forward toward the forward edge of the opening  105 . In so doing, the tarpaulin segment  140  between the rear support member  130  and the adjacent support member  120  folds into a compressed state, the rear support member  130  contacts the adjacent support member  120  and both the rear support member  130  and the adjacent support member  120  continue to move forward toward the forward edge of the opening  105 . This process continues until all of the tarpaulin segments  140  are folded into compressed states, and all of the support members  120  and  130  are arranged side-by-side at the front of the opening  105 , as shown in  FIG. 2 . In this configuration, a substantial portion of the opening  105  is open, and the interior of the trailer  100  is accessible. 
     Alternatively, the trailer  100  can be opened by sliding the front support member  130  rearward toward the rearward edge of the opening  105 . In so doing, essentially the same process as is described above occurs in reverse, resulting in the configuration shown in  FIG. 3 . In this configuration, a substantial portion of the opening  105  is open, and the interior of the trailer  100  is accessible. 
       FIG. 4  illustrates an embodiment of the support member  120 . The support member  120  has a lower plate  410 , an upper plate  412 , and a support beam  415  extending from the lower plate  410  to the upper plate  412 . The components of the support member  120  (i.e., the lower plate  410 , the upper plate  412  and the support beam  415 ) can be made from any material suitable for use to make structural components of a trailer; by way of example, stainless steel or aluminum can be used. By way of example, the lower plate  410  and upper plate  412  can be 4″ square. The lower plate  410  and upper plate  412  can be made larger than this, as illustrated in  FIG. 4 ; however, if they are made smaller, they may be prone to tipping forward or backward when being slid along the length of the opening  105 , thus causing the system to jam. The support beam  415  can have a cross-section of 2″ by 1.625″, and can have any height suitable to allow the support member  120  to extend across the height of the opening  105 . The support member  120  also comprises two lower rollers  420  and two upper rollers  430 , rotatably attached to the lower plate  410  and upper plate  412 , respectively. 
       FIG. 5  illustrates an embodiment of the support member  130  that can be used as the front support member or the rear support member. The support member  130  has a lower plate  510 , an upper plate  512 , and two support beams  515  extending from the lower plate  510  to the upper plate  512 . As can be seen in  FIG. 5 , the lower plate  510  and upper plate  512  are wider than the lower plate  410  and upper plate  412  used in respect of the support member  120 , and the support beams  515  extend from the lower plate  510  to the upper plate  512  at either end of said plates. These features make the support member  130  more resistant to tipping forward or backward when being pushed forward or backward during operation of the curtain wall  110 . Thus, the support member  130  is less prone to jamming during use. By way of example, the components of the support member  130  (i.e., the lower plate  510 , the upper plate  512  and the support beam  515 ) can be made from any material from which the support member  120  can be made. The lower plate  510  and upper plate  512  can be 12″ square. The lower plate  510  and upper plate  512  can be wider as well, to make the support member  130  even less prone to jamming during operation. The lower plate  510  and upper plate  512  also can be taller, to accommodate any special needs of the cargo that may exist. The support beams  515  can have the same dimensions as those of the support beams  415 . The support member  130  also comprises four lower rollers  520  and four upper rollers  530 , rotatably attached to the lower plate  510  and the upper plate  512 , respectively. 
     The tarpaulin segments  140  can be attached to the support members  120  as shown in  FIG. 4A . In particular, the support beam  415  can be formed with barrels  417  on the inwardly-facing surface thereof, each of which forms a receiving space  419  therein. The ends of the tarpaulin segments  140  can be inserted in the receiving space  419  by way of opening  418 . 
     On either the front support member  130  or the rear support member  130 , a sliding tarp connector (not shown) can be provided to allow the horizontal curtain tension to be adjusted across the entire opening  105 . The sliding tarp connector comprises a vertical plate attached to either the front support member  130  or the rear support member  130 , with a horizontal slot which allows the end tarpaulin segment  140  to be attached. The tension of the end tarpaulin segment  140  can be adjusted by tilting top or bottom. 
     The manner in which the support members  120  and  130  are slidably attached to the trailer  100  will now be described, with reference to  FIG. 6  and  FIG. 7 . The support members  120  and  130  are attached to the trailer  100  at the lower rollers  420 ,  520  and the upper rollers  430 ,  530 . The lower rollers  420 ,  520  and the upper rollers  430 ,  530  can be of any round shape that allows for the support members  120 ,  130  to roll. In particular, the upper rollers  430 ,  530  can comprise tapered wheels, as shown in  FIG. 6 , which can glide with less friction. As well, the lower rollers  420 ,  520  can be of a disk-like shape having a groove in the outer surface thereof, similar to that of a sheave, to facilitate slidable attachment of the support members  120 ,  130  to the trailer  100 . A groove of this nature can be seen in  FIG. 7 . 
     The upper rollers  430 ,  530  are received in an upper track  610 , which can be affixed to the trailer  100  above the opening  105  in any manner suitable to support the combined weight of each of the support members  120 ,  130  and the tarpaulin segments  140 . The upper track  610  is an elongate, “U”-shaped bracket. The upper track  610  receives the upper rollers  430 ,  530  in an interior space defined thereby, and allows the upper rollers  430 ,  530  to roll within the interior space, along the length of the upper bracket  610 . The “U”-shaped cross section of the upper track  610  helps to prevent the build up of road debris in the track, which improves the operability of the curtain wall  110 . 
     The lower rollers  420 ,  520  are received in a lower track  710 , which can be affixed to the trailer  100  below the opening  105  in any manner suitable to support the weight of the lower track  710 . Similar to the upper track  610 , the lower track  710  is an elongate, “C”-shaped bracket. The lower track  710  receives the lower rollers  420 ,  520  in an interior space defined thereby, and allows the lower rollers  420 ,  520  to roll within the interior space, along the length of the lower bracket  710 . 
     In some embodiments, the lower track  710  can have a ridge  720  projecting downwardly from an upper portion of the lower track  710 , and having a shape complimentary to the groove provided in the lower rollers  420 ,  520 . In such embodiments, the length of the support beams  415 ,  515  can be selected such that, when the upper rollers  430 ,  530  are received in the upper track  610 , the lower rollers  420 ,  520  are held in place against the upper portion of the lower track  710 , with the groove of the lower rollers  420 ,  520  engaging the ridge  720 . In such a configuration, the lower rollers  420 ,  520  are held securely in the lower track  710 , and can resist forces that tend to pull the support members  120 ,  130  out and away from the trailer  100 . 
     Referring to  FIG. 8 , an alternative embodiment of a support member  120  is shown, in which a third lower roller  420  is provided. The additional lower roller  420  is provided above the other two lower rollers  420 , and is intended to engage and slide along the top surface of the lower track  610 . In such embodiments, the lower track  610  can be provided with a second ridge (not shown) extending upwardly from the top of the lower track  610 , for engaging the groove of the third lower roller  420 . Using this configuration, the support member  120  is even more securely attached to the trailer  100 . 
     It will be apparent to those having ordinary skill in the art that certain adaptations and modifications of the described embodiments can be made, consistent with and without departing from the present invention. Unless otherwise indicated, the embodiments described in the invention shall be understood to be non-exclusive of each other such that any embodiment can include different features of other embodiments. Therefore, the above discussed embodiments are considered to be illustrative and not restrictive. Other embodiments consistent with the present invention will become apparent from consideration of the specification and the practice of the present invention taught and suggested herein. Accordingly, the specification and the embodiments disclosed therein are to be considered exemplary only, with the true scope of the present invention being identified in the following claims.