Abstract:
A retractable top covering system has a top covering configured to cover an open top area of a container having sides that define an interior space. The top covering is connected to a retractable top drive mechanism that selectively retracts and deploys the retractable top covering. A track is supported along an upper edge of the container around a portion of the open top area. The track supports at least one trolley for relative movement along the upper edge of the container. A support bow is connected the trolley and supports the retractable top covering. A cable, connected between the retractable top drive mechanism and the trolley, moves the trolley along the track in response to retraction and deployment action of the retractable top drive mechanism.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/130,390, filed Mar. 9, 2015, the disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    This invention relates in general to covering systems used in tractor-trailer hauling applications. In particular, this invention relates to a power actuated top covering system for selectively covering the open top area of a trailer having rigid side walls. 
         [0003]    Commercial truck trailers are produced in a variety of forms to support and haul a variety of goods. Flat bed trailers are designed to haul heavy loads, such as coiled steel or larger pieces of equipment, and permit these loads to be placed on the trailer surface easily. Box trailers tend to haul lighter packaged goods that need to be protected from wind loads during transport. Open top, dump trailers configured to haul generally loose and dry goods, such as grain, sand, gravel and the like, have generally rigid side walls and a rear mounted gate or a bottom-mounted chute or door. The open top permits the goods to be loaded into the trailer. The gate permits goods to be released as the trailer is tilted. The bottom-mounted door permits unloading without the need to tilt the trailer. 
         [0004]    Open top dump trailers, because of the loose nature of their cargo, are often covered to prevent road wind from blowing the trailer contents onto the roadway and onto other vehicles following behind. Many states require certain types of loose cargo to be covered to prevent debris from impacting other vehicles. These top coverings may be canvas or rigid panels. Canvas coverings are usually rolled, either to one side or an end of the trailer, to deploy or remove the cover. The rolling mechanism may include a U-shaped “towel” bar that extends along the outer surface of the side walls and pivotally mounts to the lower portion of the trailer. The tarp is rolled onto or off of the towel bar portion that extends across the trailer as the side arms are pivoted. Other types of deployment mechanisms may include a hand operated crank that rotates a take-up bar to roll up the tarp covering. These types of deployment devices are prone to damage because they mount on the exterior of the trailer bed or become cumbersome to operate. Thus, it would be desirable to provide a tarp deployment system for an open top trailer that improves deployment and durability. 
       SUMMARY OF THE INVENTION 
       [0005]    This invention relates to covering systems used in tractor-trailer hauling applications. In particular, this invention relates to a power actuated top covering system for selectively covering the open top area of a trailer having rigid side walls. 
         [0006]    A retractable top covering system has a top covering configured to cover an open top area of a container having sides that define an interior space. The top covering is connected to a retractable top drive mechanism that selectively retracts and deploys the retractable top covering. A track is supported along an upper edge of the container around a portion of the open top area. The track supports at least one trolley for relative movement along the upper edge of the container. A support bow is connected the trolley and supports the retractable top covering. A cable, connected between the retractable top drive mechanism and the trolley, moves the trolley along the track in response to retraction and deployment action of the retractable top drive mechanism. 
         [0007]    Various aspects of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is an exploded, perspective view of a container having a retractable top cover mechanism in accordance with various embodiments of the invention. 
           [0009]      FIG. 2  is an elevational view of a support bow and trolley assembly. 
           [0010]      FIG. 3  is an elevational view of a top actuating assembly. 
           [0011]      FIG. 4  is an enlarged side view of an end portion of a track and a top actuating mechanism. 
           [0012]      FIG. 5  is a perspective view of the track and actuating mechanism of  FIG. 4 . 
           [0013]      FIG. 6  is an enlarged side view of a driving portion of the track and top actuating mechanism of  FIG. 3 . 
           [0014]      FIG. 7  is an end view of the track of  FIGS. 4-6 . 
           [0015]      FIG. 8  is an end view of a trolley assembly engaging the track of  FIG. 7 . 
           [0016]      FIG. 9  is an enlarged view of a roller support assembly of the track and trolley assembly of  FIG. 8 . 
           [0017]      FIG. 10  is a side view of the trolley of  FIG. 8 . 
           [0018]      FIG. 11  is an end view of the trolley of  FIG. 10 . 
           [0019]      FIG. 12  is an exploded, perspective view of the trolley of  FIGS. 10 and 11 . 
           [0020]      FIG. 13  is an enlarged, perspective view of an end portion of the support bow and trolley assembly of  FIG. 2 . 
           [0021]      FIG. 14  is an exploded view of a portion of the support bow and trolley assembly of  FIG. 13 . 
           [0022]      FIG. 15  is an enlarged side view of another embodiment of a rear portion of the track and top actuating mechanism of  FIG. 4  having a rear pulley module. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0023]    Referring now to the drawings, there is illustrated in  FIG. 1  a container  10  having a retractable top covering mechanism  12 . A top cover  14  is shown removed from the container  10 . The top cover  14  may be formed as a hard covering structure, such as a segmented series of metal or polymer panels or a soft covering structure, such as a tarp sheet, canvas, or other flexible cover. An example of a single tarp covering  14  is illustrated in  FIG. 1 . The container  10  may be any type of cargo containment vessel having a generally open top surface, such as for example a dump bed, box container, grain hauler, and the like. The retractable top covering mechanism  12  includes a plurality of support bow and trolley assemblies  16  that span the open top surface of the container. The bow and trolley assemblies  16  are mounted to spaced-apart tracks  18 , attached to the sides of the container  10  for relative movement therewith. 
         [0024]      FIG. 2  is an end view of the support bow and trolley assembly  16 . The bow and trolley assembly  16  includes a support bow  20  that is illustrated as a single member having an offset that defines a sloped surface. The sloped surface permits water runoff and load transfer of environmental loads to trolley assemblies  22  and the track  18 . Alternatively, the bow  20  may be two halves, joined by an angled member (not shown) to form the offset. The support bow  20  has trolley assemblies  22  connected at either end to mount and support the bows  20  relative to the tracks  18 . As shown in  FIGS. 13 and 14 , the trolley assembly  22  includes a trolley  24  and bow riser  26 . A cable support  28  is disposed within the bow riser  26 . A bow bracket  30  connects to the bow riser  26  and includes a bow locating section  30   a  that locates against the support bow  20 . An offset surface  30   b  locates against the bow riser  26  to define the offset of  FIG. 2 . The cable support  28  is illustrated as a block shaped support having an aperture  28   a  formed therethrough. The aperture  28   a  permits a cable or other actuating structure (i.e., chain, rope, tube, wire, and the like) to connect to the trolley assembly  20 . The cable support  28  also permits the cable to be secured to the trolley assembly  20  without substantially distorting the bow riser  26  during attachment or subsequent movement of the structure. 
         [0025]    Referring now to  FIGS. 1, 3 and 6 , a drive assembly  32  is shown that spans the width of the container  10 . The drive assembly  32  is illustrated in  FIG. 1  as being mounted to the front portion of the container, though such is not required. The drive assembly  32  includes a power drive unit  34  and a manual drive unit  36 . The power drive unit  34  is illustrated as a power driven gear box used for powered operation of the top covering  14 . The manual drive unit  36  is illustrated as a gear box having an input for non-powered operation by, for example, a hand crank (not shown). A shaft assembly  38  connects the power and manual drive units  34  to drive pulleys  40 , shown best in  FIG. 6 . The drive pulley  40  supports a cable  42  that interconnects the support bow and trolley assemblies  22 . As shown in  FIG. 4 , the cable  42  forms a loop around two spaced apart end pulleys  44 . Alternatively, the end pulleys  44  may be any number of pulleys, including a single pulley, similar to drive pulley  40 . The ends of the cable  42  are connected together by one or more turnbuckles  46  to provide tensioning adjustment and ease of removal and installation of the cable  42 . The turnbuckles  46  may be connected together or connected to one of the trolleys  24 . 
         [0026]    As shown in  FIG. 15 , the end pulleys may be configured as part of an end pulley module, shown generally at  100 . The end pulley module  100  includes a frame  102  that supports a first end pulley  104  and a second end pulley  106  for rotation. The first end pulley  104  is shown having a larger diameter than the second end pulley  106 , though such is not required. The frame  102  includes a pulley housing  108  and a pair of opposed mounting ears  110  extending therefrom that attach to the track  18 . The mounting ears  110  may be configured for attachment to the track in either a single position or for adjustability relative to the track  18  to vary tension in the cable  42 . The frame  102  further includes a support cover  112 . The pulley housing  108  and the support cover  112  include apertures  114  that support axles  116 . The pulleys  104  and  106  are supported for rotation on the axles  116 . 
         [0027]    Referring now to  FIGS. 7, 8, and 9 ; an end view of the track  18  is shown. The track  18  includes a bow reaction channel  48 , a track glide channel  50 , and a shield channel  52 . The bow reaction channel  48  includes spaced apart reaction surfaces  54   a  and  54   b.  The reaction surface  54   a  is formed on a hook  56 . The other reaction surface  54   b  is formed on a back wall  58  of the track  18 . The size of the bow reaction channel  48  permits rollers  60  to contact the surfaces  54   a  and  54   b  and provide a reacting moment to the bow load, L shown in  FIG. 8 . In one embodiment, the rollers  60  are each sized to contact only one surface, thus permitting the rollers to counter-rotate as the trolley  24  traverses the container  10 . 
         [0028]    The track glide channel  50  supports a load roller  62  which carries the weight of the bow and covering section and vertical forces from the environmental loads. The reaction rollers  60  reduce moment loads applied to the load roller  62  in order to create a smooth, reduced effort movement of the trolley  24  against the track  18 . In one embodiment, the reaction rollers  60  and the load roller  62  have curved outer surfaces to permit the rollers to maintain a path characterized by a general line-contact pattern. The track glide channel  50  may include a groove  64 , illustrated as a dovetail groove, to retain a glide strip  66 . The groove  64  may be any shape that accommodates the glide strip  66 . The trolley  24  includes a carrier bracket  68  that supports the bow riser  26 , the reaction rollers  60  and the load roller  62 . The carrier bracket  68  further includes a sealing flange  70  that extends into the shield channel  52  to limit the intrusion of debris and dirt from the road or environment. The carrier bracket  68  includes a top cover mounting channel  72  that supports side portions of the top cover to improve the sealing out of contaminants or retaining cargo particulate within the container. 
         [0029]    The carrier bracket  68  includes a bow mounting flange  74  that supports the bow riser  26 , which may be welded, or otherwise secured to the trolley  24 . A reaction roller mounting flange  76  extends from the back wall  58  and is sized to locate the reaction rollers  60  within the bow reaction channel  48 , as described above. A load flange  78  is sized such that the load roller  62  is generally centered under a reaction roller rotational axis, A. This minimizes any moments applied to the load roller  62 , which extends the available bearing life associated with the rollers. 
         [0030]    In operation of the embodiment of  FIG. 1 , the tracks  18  are oriented along the upper edge of the container  10 , which may be a dump bed, for example. The tarp covering  14 , when in the closed position, has side walls or flaps that extend over a portion of the trolley and into the sealing channel. When the top is to be opened, the drive assembly  32  is actuated, either by power or manually, which rotates the shafts  38  and the pulleys  40 . The cable  42  is attached to the bow riser, either as a continuous cable or as discrete cable sections between the bow and trolley assemblies, and driven by the pulley  40 . The cable  42  passes through the bow risers of the trolleys and may be a slip fit through the aperture  28   a.  In one embodiment, the bow furthest from the drive pulley and closest to the end pulleys connects the cable ends (at the turnbuckles) such that the cable pulls the last bow into the preceding bows toward the drive unit. The tarp cover then folds or bunches together between the bows exposing the cargo area of the container. The closing operation drives the last bow rearward by reversing the direction of the drive unit and the cable. 
         [0031]    The principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.