Abstract:
A cover system for covering an open top of a container includes a flexible cover, a bail member, a bow member, and a tension element. The cover has a first end connected to the container and is sized to cover the open top when a second end is in an extended position. The bail member has an end pivotally connected to the container and an end connected to the second end of the cover. The bail member pivots to deploy the cover into the extended position. The bow member includes an end pivotally connected to the bail member and an end configured to bear against the cover between the ends of the cover. The tension element is connected between the container and the bow member. The tension element applies a force to the bow member to apply a force against the cover.

Description:
[0001]    This application is a utility application claiming priority to U.S. provisional patent application Ser. No. 61/730,873, filed on Nov. 28, 2012, entitled “Tensioning Bow Assembly for a Flexible Cover System,” the disclosure of which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    The present disclosure relates to flexible covers or tarping systems for open-topped containers and particularly concerns a mechanism for restraining the flexible cover or tarp against the container. 
         [0003]    Many hauling vehicles, such as dump trucks, include open-topped containers used for hauling or storing various materials. In a typical dump truck application, the open-topped container is referred to as the “dump body” of the truck. The dump body is used to haul a variety of load material, such as gravel and the like, as well as organic materials, such as grain or produce. Upon reaching the dumping site, the dump truck tilts the dump body to evacuate the load material from the dump body. 
         [0004]    Depending upon the nature of the load material stored in the open-topped container, it is often desirable to provide a cover for the container. A cover is particularly valuable for covering the dump body of a dump truck when dump truck is in transit. Rigid covers are well known that may be hinged from one end of the container body and pivoted from an open to a closed position. While rigid covers may be acceptable for stationary containers, the same is usually not true for containers associated with land-traversing vehicles. Accordingly, rigid covers have given way to flexible cover systems. 
         [0005]    Flexible cover systems utilize a flexible tarpaulin that can be drawn from a stowed position at one end of the container, to a deployed position covering the open top of the container. The flexible tarpaulin is preferable for dump trucks, because it can be easily stowed when the cover is not needed, such as during times when the dump body is being loaded and emptied. In addition, flexible cover systems are generally easier to deploy than rigid covers. 
         [0006]    A variety of flexible cover systems have been developed that are geared toward particular hauling vehicle applications. One such tarping system is the Easy Cover® Tarping System manufactured and sold by Aero Industries, Inc. An example of one form of the Easy Cover® Tarping System is shown in  FIG. 1 . The system includes a U-shaped bail member  22  that is connected at a pivot mount  25  to the base of the container body  13  on the vehicle  10 . A horizontal section  27  of the bail member  22  is attached to the tarp  16 . The system also includes a U-shaped tensioning bow member  30  that is connected at a pivot mount  32  to the bail member  22 . The tarp  16  is positioned between a horizontal section  34  of the tensioning bow member  30  and the container body  13 . The tarp  16  can be preferably stowed by winding onto a tarp roller  19  at the forward end of the vehicle, which causes the tarp to slide under the horizontal section  34  of the tensioning bow member  30  as the bail member  22  pivots toward the front of the container body  13 . 
         [0007]    The system includes a variety of configurations that permit manual or powered deployment of the tarp over the open top of the container. In one typical installation, the pivot mount  25  includes a torsion spring pack that is biased to rotate the bail member  22  in a clockwise direction, as shown in  FIG. 1 , to pull the tarp  16  over the top of the container  13 . The tarp roller  19  is biased to resist this rotation of the bail member  22 . In some versions, a manual crank rotates the tarp roller  19  to allow the tarp  16  to unfurl under the torsion force of the spring pack. In other versions, a motor controls the rotation of the tarp roller. The manual crank or motor are rotated in the opposite direction to pull the bail member  22  toward the front of the container body  13  and to thereby stow the tarp  16 . 
         [0008]    One problem that is faced with tarping systems of the type shown in  FIG. 1  is the effect of airflow or wind on the tarping system as the vehicle is traveling. In particular, the tarpaulin  16  is affected in a number of ways by the airflow associated with the traveling vehicle. This problem becomes especially acute at high speeds. In particular, the front end of the vehicle creates turbulent airflow that travels along the length of the container body  13 . The turbulence, which can be manifested by air vortices along the top of the container body  13 , has a tendency to lift the flexible cover  16  away from the top of the body. 
         [0009]    Another problem facing the above-described tarping system is road vibration and shock, which can cause the bail member  22  and the tensioning bow member  30  to bounce on the container body  13  when the tarp  16  is deployed. This problem is especially noticeable for systems including the tensioning bow member  30 , the position of which is maintained by only the weight of the tensioning bow member  30 . 
         [0010]    Movement of the tarp  16 , the bail member  22 , and the tensioning bow member  30  due to wind and vibration may have a deleterious effect is on the flexible cover system. The constant flapping and bouncing can gradually wear the tarp and the cover system components, which decreases the longevity of the cover system. In addition, when the tarp  16  is dislodged from its deployed position, the contents of the container body  13  are at risk of expulsion. 
         [0011]    In order to address this problem, various systems have been devised to bias the tarp against the container body. In one common cover system, a web of cords is deployed over the tarp  16  along the length of the container body  13 . The ends of the cords can be attached to mounts affixed to the side of the body  13 . Whereas other cover systems rely on a complicated array of mechanical, electrical, and/or hydraulic structures to apply a constant tension along the length of the tarp  16 . In most cases, however, these cover systems do not adequately restrain the bail/bow members  22 ,  30  or the tarp  16 . 
         [0012]    Another system is disclosed in U.S. Pat. No. 8,267,461 that contemplates a tarping system  100  for an open-topped container  120  includes a bail member, shown as a U-shaped tensioning bow member  102 , and another U-shaped bail member  104 , as shown in  FIG. 2 . The bail member  104  includes two legs  105  with end portions of the legs  105  connected to the bottom of the container  120  by a pair of torsion spring packs  134  (only one of which is illustrated in  FIG. 2 ). The tensioning bow member  102  includes a pair of legs  103  and a horizontal mid-section  112 . As described in the &#39;461 Patent, the disclosure of which is incorporated herein by reference, the end portion of each leg  103  is connected to the legs  105  of the bail member  104  by another pair of torsion spring packs  108  (only one of which is illustrated in  FIG. 2 ). The spring packs  108  include a housing  109  for one or more biasing springs (not shown) that is engaged to a mount  132  for fixing the spring packs to the bail member. The spring packs  108  form a hold-down assembly that is configured to bias the horizontal section  112  of the tensioning bow member  102  against the tarp  124  and an upper edge  128  of the container  120  (or a load carried by the container, if the load is positioned above the upper edge  128 ) to restrain movement the tensioning bow member  102 . Accordingly, the horizontal section  112  is positioned against the tarp  124  by a force greater than just the weight of the bail member  102 . The spring packs  108  exert a biasing force that is greater than the force exerted upon the tensioning bow member  102  by normal wind and/or gravity, among other effects. 
         [0013]    Most prior approaches to maintaining the tarp against the container body either require manual intervention or sophisticated powered components. Accordingly, there remains a need for an improved tarping system having a tensioning bow member which is less prone to the wind and vibrations associated with a moving container. 
       SUMMARY 
       [0014]    In one aspect, a cover system is provided for covering an open top of an open-topped container with a flexible cover, the flexible cover having one end connected to the container, and the flexible cover sized to substantially cover the open top when an opposite end of the flexible cover is moved to an extended position. The cover system comprises a bail member having a first end pivotally connected to the container and an opposite second end connected to the opposite end of the flexible cover. The bail member is configured for movement from a stowed position to a deployed position in which the flexible cover is in the extended position. The cover system further includes a tensioning bow member including an end portion pivotally connected to the bail member and horizontal bar at an opposite end configured for bearing against the flexible cover between the ends thereof. 
         [0015]    In one feature, the system includes a mechanism for holding the tension bow member in engagement or contact with the flexible cover with sufficient force to prevent the cover and tension bow member from bouncing or flapping under wind and vibration conditions. The mechanism includes an elastic cable, such as a bungee-type cord, fastened between the horizontal bar of the tension bow member and a mount at the base of the open-topped container. The elastic cable moves freely with the tension bow member as the cover is unfurled or deployed. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0016]      FIG. 1  is a top perspective view of a hauling vehicle utilizing a flexible cover system. 
           [0017]      FIG. 2  is a perspective view of a prior tension bow mechanism for a flexible cover system disclosed in U.S. Pat. No. 8,267,461. 
           [0018]      FIG. 3  is a side perspective view of a deployment assembly for a flexible cover system incorporating a tension bow mechanism according to a disclosed embodiment, shown with the cover system in an undeployed or open configuration. 
           [0019]      FIG. 4  is a side perspective view of the deployment assembly illustrated in  FIG. 3 , shown with the cover system in partially deployed configuration 
           [0020]      FIG. 5  is a side perspective view of the deployment assembly illustrated in  FIGS. 3-4 , shown with the cover system in a deployed or closed configuration 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It should nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. The disclosure includes any alterations and further modifications in the illustrated devices and described methods and further applications of the principles of the disclosure that would normally occur to one skilled in the art to which the disclosure relates. In the drawings, like reference numerals have been used throughout to designate like elements. 
         [0022]    Referring to  FIGS. 3-5 , a flexible cover system  200  to be used in conjunction with a container  202  according to one embodiment is shown. The container  202  has an open top, a first side wall  203 , a second side wall  204  opposite the first side wall  203 , a proximal wall  205  positioned nearest the truck (shown in  FIG. 1 ), a distal wall  206  opposite the proximal wall  205 , and a bottom wall  207 . Together, the walls  203 ,  204 ,  205 ,  206 , and  207  define an interior volume that is utilized to hold a load. The cover system  200  is coupled to the container  202  and includes a flexible cover or tarpaulin  250 , a roller assembly  252 , a tension bow assembly  220 , and a bail arm assembly  210 . The cover  250  is wound onto the roller assembly  252  in a conventional manner and is deployed by the bail arm assembly  210  to cover the open top of container  202  in its deployed configuration (shown in  FIG. 5 ). 
         [0023]    The cover  250  includes a roller end  251  coupled to the roller assembly  252  and includes a bail arm end  209  coupled to the bail arm assembly  210 . The cover  250  is shaped and sized such that when the cover  250  is in the deployed configuration (shown in  FIG. 5 ), the roller end  251  is positioned adjacent to the proximal wall  205  of the container and the bail arm end  209  is positioned adjacent to the distal wall  206  so that the cover  250  extends over the open top of the container  202 . When the cover  250  is in the open configuration (shown in  FIG. 3 ), the cover  250  is wound onto the roller assembly  252  such that both the roller end  251  and the bail arm end  209  are positioned adjacent to the proximal wall  205  so that the cover  250  does not extend over the open top of the container  202 . 
         [0024]    The roller assembly  252  includes a retraction mechanism  253 , such as is known in the art, and includes a roller  254  configured to be rotated by the retraction mechanism  253 . The roller end  251  of the cover  250  is coupled to the roller  254  such that when the retraction mechanism  253  rotates the roller  254  in a first direction D 1 , the cover  250  is wound onto the roller  254  and when the retraction mechanism  253  rotates the roller  254  in a second opposite direction D 2 , the cover  250  is unwound from the roller  254 . 
         [0025]    The bail arm assembly  210  includes a pair of vertical legs  212  and a horizontal bar  215  coupled to both vertical legs  212 . The horizontal bar  215  is also coupled to the bail arm end  209  of the cover  250 . Each of the vertical legs  212  is rotatably mounted to the container  202  at a pivot point  216  positioned on the outsides of the side walls  203 ,  204  of the container  202 . The bail arm assembly  210  also includes an actuation mechanism  218  coupled to one of the vertical legs  212  at the pivot point  216 . The actuation mechanism  218  is configured to exert a torque on the vertical leg  212  at the pivot point  216  to rotate the bail arm assembly  210  away from the roller assembly  252 . By way of example, the actuation mechanism  218  can be a torsion spring positioned at the pivot point  216 . The actuation mechanism  218  moves the horizontal bar  215  away from the roller assembly  252  and toward the distal wall  206  of the container  202 , thereby pulling the bail arm end  209  of the cover  250  toward the deployed position (shown in  FIG. 5 ). 
         [0026]    In the embodiment shown, the bail arm assembly  210  includes only one actuation mechanism  218  which moves both vertical legs  212  and the horizontal bar  215  by exerting a torque on one vertical leg  212 . In at least one alternative embodiment, however, the bail arm assembly  210  can include two actuation mechanisms  218 , one for each of the vertical legs  212 , to operate simultaneously on opposite sides of the container  202 . 
         [0027]    In the embodiment shown, the actuation mechanism  218  is configured to bias the bail arm assembly  210  away from the roller assembly  252  such that the horizontal bar  215  is biased toward the distal wall  206  of the container  202 , and the retraction mechanism  253  is configured to actively rotate the roller  254  in both the first direction D 1  and the second direction D 2 . Additionally, the retraction mechanism  253  is further configured so as to apply a rotational force in the first direction D 1  that is large enough to overcome the torque that is applied by the actuation mechanism  218  to bias the bail arm assembly  210 . Accordingly, when the retraction mechanism  253  of the roller assembly  252  actively rotates the roller  254  in the first direction D 1 , the torque applied by the actuation mechanism  218  is overcome, the cover  250  is wound onto the roller  254 , and the bail arm assembly  210  is rotated toward the roller assembly  252  as the bail arm end  209  of the cover  250  pulls the horizontal bar  215  toward the roller assembly  252 . Conversely, when the retraction mechanism  253  of the roller assembly  252  actively rotates the roller  254  in the second direction D 2 , the actuation mechanism  218  biases the horizontal bar  215  away from the roller assembly  252 , unwinding the cover  250  from the roller  254  as the horizontal bar  215  pulls the cover  250  toward the deployed position. In at least one alternative embodiment, however, the retraction mechanism  253  can be configured to actively rotate the roller  254  in only the first direction Dl and/or the actuation mechanism  218  can be configured to actively move the horizontal bar  215  of the bail arm assembly  210  toward and away from the deployed position. 
         [0028]    The cover system  200  further includes a tension bow assembly  220  and two elastic tension elements  230 . The tension bow assembly  220  includes a pair of vertical legs  222  and a horizontal bar  228  coupled to both vertical legs  222 . The vertical legs  222  are positioned on the outsides of the side walls  203 ,  204 , and the horizontal bar  228  is situated on the outside of the cover  250 , in the same manner as the horizontal section  112  of the mechanism shown in  FIG. 2 . The elastic tension elements  230  are connected to the horizontal bar  228  of the tension bow assembly  220  and to mounts  232  located on each of the side walls  203 ,  204  at the bottom wall  207  of the container  202 . In one embodiment, the elastic tension elements  230  are elastic cables or cords, such as bungee cords. The elastic tension elements  230  can be connected to the horizontal bar  228  and to the mounts  232  in a conventional manner, such as by a brackets or collars. In at least one alternative embodiment, the cover system  200  includes only one elastic tension element  230  coupled to just one mount  232  located on one side of the container  202 . 
         [0029]    Each of the vertical legs  222  of the tension bow assembly  220  includes a pivot end  223  and horizontal bar end  229 . The pivot end  223  of each vertical leg  222  is pivotably mounted to one of the vertical legs  212  of the bail arm assembly  210 . In particular, each vertical leg  212  of the bail arm assembly  210  includes a bracket  226 , and the pivot end  223  of each vertical leg  222  of the tension bow assembly  220  is mounted to a respective bracket  226  at a pivot engagement  224 . The horizontal bar end  229  of each vertical leg  222  is mounted to the horizontal bar  228  adjacent to the elastic tension element  230 . 
         [0030]    Due to its elasticity, each elastic tension element  230  is configured to exert a force toward the center  231  of the elastic tension element  230  that is a function of the elasticity of the elastic tension element  230  and of the amount that the elastic tension element  230  is stretched. Because the mount  232  is fixed in position relative to the container  202  and the flexible cover system  200 , the elastic tension element  230  exerts the force toward the mount  232 . When the cover  250  is in the deployed position (shown in  FIG. 5 ), the horizontal bar  228  is a first distance H 1  away from the mount  232 , stretching the elastic tension element  230  a first length L 1  and exerting a first force F 1  on the horizontal bar  232 . As the cover  250  is moved to the partially deployed position (shown in  FIG. 4 ), the horizontal bar  228  is a second distance H 2  away from the mount  232 , stretching the elastic tension element  230  a second length L 2  and exerting a second force F 2  on the horizontal bar  232 . Finally, as the cover  250  is moved to the open position (shown in  FIG. 3 ), the horizontal bar  228  is a third distance H 3  away from the mount  232 , stretching the elastic tension element  230  a third length L 3  and exerting a third force F 3  on the horizontal bar  232 . 
         [0031]    In the embodiment shown, the mounts  232  are positioned closer to the distal wall  206  of the container  202  than is the retraction mechanism  253  of the roller assembly  252 . Additionally, the mounts  232  are positioned closer to the proximal wall  205  of the container  202  than are the pivot points  216  of the bail arm assembly  210 . Accordingly, due to the position of the mounts  232  relative to the other components of the flexible cover system  200 , the third length L 3  is larger than the second length L 2 , which is larger than the first length L 1 . Thus, the third force F 3  is larger than the second force F 2 , which is larger than the first force F 1 . In at least one alternative embodiment, the mounts  232  can be positioned in other locations resulting in different force distributions. Because a force is applied to the horizontal bar  228  at all positions of the flexible cover system  200 , and because the horizontal bar  228  is positioned outside of the cover  250 , the force generated by the elastic tension elements  230  and applied to the horizontal bar  228  holds the cover  250  down on the container  202  at a position between the distal wall  206  and the proximal wall  205  of the container  202 . 
         [0032]    Because, as mentioned above, the mounts  232  are situated nearer to the proximal wall  205  of the container  202  than are the pivot points  216  of the bail arm assembly  210 , when the cover  250  is fully deployed over the top of the container (as shown in  FIG. 5 ), first force Fl exerted by the elastic tension element  230  toward the mount  232  is directed in a downward direction that is nearly vertical. When the cover  250  is fully retracted from the top of the container  202  (as shown in  FIG. 3 ), the third force F 3  exerted by the elastic tension element  230  toward the mount  232  is directed at an angle of less than about 20°. Accordingly, through all positions of the cover  250  over the top of the container  202 , the elastic tension element  230  exerts force through a narrow angular range, from nearly vertical in the deployed position to an angle of less than about 20° in the retracted or open position. As the direction of the force moves from nearly vertical to the angle of less than about  20 ° , the vertical component of the force decreases. This decrease offsets the increase in force caused by the stretching of the elastic tension member  230  to longer lengths so that the vertical downward force applied to the cover  250  does not change significantly between the undeployed and deployed positions. 
         [0033]    In the embodiment shown, a separate elastic tension element  230  is provided outside each side wall  203 ,  204  of the container  202 , each with its own mount  232 . Alternatively, a single elastic tension element  230  may pass through each mount  232 , across the outside of the bottom wall  207  of the container  202 , to be connected to opposite ends of the horizontal bar  228 . 
         [0034]    With this approach, any changes in elasticity of the elastic tension element  230  are experienced equally on both sides of the tension bow assembly  220 . 
         [0035]    While the invention has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the invention are desired to be protected.