Abstract:
A bail arm assembly for a retractable tarp or cover system for a container, comprises a lower arm configured to be pivotably mounted relative to the container, an upper arm configured to support the tarp or cover, and an adjustable coupling connecting the lower arm to the upper arm. The adjustable coupling includes a pair of opposing engagement faces configured to permit selective adjustment of the angular relationship between the lower and upper arms at discrete angular intervals.

Description:
BACKGROUND 
       [0001]    The present invention relates to tarping systems for containers, such as dump bodies, transfer containers and the like. More particularly, the invention relates to the bail arms used to extend and retract the tarpaulin or cover across the open top of the container. 
         [0002]    Tarping systems for containers, particular containers carried by a vehicle, are well-known. Two examples are shown in  FIGS. 1 and 2 . The transfer container  10  in  FIG. 1  is carried by a truck T. Bail arms  14  carry a tarpaulin or cover  22  and are configured to extend the tarp across the top  12  of the container  10 , with the bail arms in the extended position  14 ′. In one configuration, the bail arms  14  include a lower arm  15 , a joint  16  and an upper arm  18  that carries a spool  20  onto which the tarp  22  is wound. In some systems the spool is mounted on a gantry and the upper arm is connected to a cross-bar fastened to the end of the tarp. The bail arms are typically spring-driven for extension with a motor-driven spool for retracting the tarp. 
         [0003]    In another container system, a dump body  25  includes a tarp  26  that extends or retracts over the open top of the dump body. One or more bail arms  27  carry the tarp across the dump body. The bail arms include a lower arm  28 , a joint  29  and an upper arm  30  connected to the tarp  26 . One or more of the bail arms bay be spring-driven for extension or retraction, with a manual pull or a motor drive working against the spring-drive feature. 
         [0004]    In both systems the joint  16 ,  29  between the lower and upper arms ( 15 ,  28  and  18 ,  30 ) is fixed, meaning that the upper arm is at a fixed angular relationship to the lower arm. This fixed relationship can be acceptable for many container sizes and configurations; however, the fixed angle does not permit flexibility in accommodating a tarping system to a particular container. For instance, the transfer container  10  shown in  FIG. 1  may be shorter than depicted, or the particular fixed angle does not pull the tarp tight and relatively flat across the open top  12  of the container. Similar problems may arise with respect to the dump body of  FIG. 2 . 
       SUMMARY 
       [0005]    In one aspect, a tarping system includes an adjustable coupling between the lower and upper arms of the tarping system bail arms. The lower arm is configured to be pivotably mounted relative to the container while the upper arm is configured to support the tarp or cover. The adjustable coupling includes a pair of opposing engagement faces configured to permit selective adjustment of the angular relationship between the lower and upper arms at discrete angular intervals. 
         [0006]    In one aspect the adjustable coupling includes two identical components, each including a corresponding engagement face. The components further include an elongated body configured to fit within the hollow passage of a corresponding bail arm. Fasteners, such as metal screws, can be used to fasten the coupling components to the bail arms. 
         [0007]    In a further aspect, each component includes a head portion that carries a corresponding engagement face. The engagement face is configured for interdigitating engagement, such as by way of radial teeth or splines. The interdigitating engagement face is configured to permit discrete adjustment of the angular relationship between bail arm members, such as discrete five degree adjustments. The engagement face is further configured to permit adjustment of the angular relationship from a linear arrangement (i.e., 180°) to a predetermined angular offset up or down, such as ±102.5°. A clamping assembly is operable to clamp the two components together at a desired angular orientation. 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0008]      FIG. 1  is a depiction of a prior art container tarping system. 
           [0009]      FIG. 2  is a depiction of another prior art container tarping system. 
           [0010]      FIG. 3  is an exploded view of an adjustable coupling for use in the bail arms of a container coupling system, such as the systems shown in  FIGS. 1-2 . 
           [0011]      FIG. 4  is a top cross-sectional view of a component of the adjustable coupling shown in  FIG. 3 . 
           [0012]      FIG. 5  is an end cross-sectional view of the engagement between the adjustable coupling and a bail arm. 
           [0013]      FIG. 6  is an enlarged perspective view of the angle adjustment feature of the adjustable coupling shown in  FIG. 3 . 
           [0014]      FIG. 7  is a perspective view of the adjustable coupling of  FIG. 3  shown in its assembled configuration. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one skilled in the art to which this invention pertains. 
         [0016]    A bail arm assembly  50  is shown in  FIG. 3  which includes an adjustable arm coupling  52  connecting the lower arm  15  to the upper arm  18 . It is understood that the lower and upper arms may be similar to the bail arm components shown in  FIGS. 1 and 2 , or any other bail arm construction used for retractable/extendable tarping system. In one embodiment, the adjustable arm coupling  52  includes an upper component  54  and a lower component  55  that are pivotably and adjustably engaged, as explained in more detail herein. In one aspect, the two components  54 ,  55  may be identically configured for ready interchangeability when installing the arm coupling in a bail arm assembly. 
         [0017]    The two components  54 ,  55  include an elongated body  57 ,  67  that is adapted for a close-fit engagement within the hollow passage  72 ,  74  in a respective lower or upper bail arm  15 ,  18 . It can be appreciated that the elongated bodies  57 ,  67  exhibit a profile or cross-sectional shape that may generally conforms to the profile or cross-sectional shape of the hollow passage  74 . This conformity helps seat the body  57 ,  67  within the bail arm component  28 ,  30  and prevents relative rotation between the parts. The cross-sectional shape of the elongated bodies  57 ,  67  may be modified to reduce the amount of material while retaining sufficient strength to endure the bail arm loads without compromise. Thus, as shown in the cross-sectional view of  FIG. 4 , the body  57  may incorporate a hollowed portion  57   a  on opposite sides of the body to reduce the material requirements. The elongated bodies are fastened to the corresponding bail arm component by appropriate fasteners  77 , which may be, for instance, sheet metal screws. 
         [0018]    Returning to  FIG. 3 , the components  54 ,  55  include head portions  58 ,  68  that are configured for adjustable mating engagement. In one embodiment, the head portions define an engagement face  59 ,  69  adapted for selective adjustable engagement at various discrete relative angular orientations. In one specific embodiment the engagement faces  59 ,  69  may incorporate a series of radial splines or teeth  59   a  adapted for interdigitating engagement, as shown in  FIG. 6 . The head portion may incorporate an angle indicator with visible indicia indicative of the relative angle defined by the engagement of the two components  54 ,  55 . 
         [0019]    Once the two components are oriented at a desired angle, as shown in  FIG. 7 , the upper and lower components  54 ,  55  can be clamped together using a clamping assembly  75 . The clamping assembly extends through a corresponding bore  58   a,    68   a  in the two components. In one embodiment the clamping assembly  75  may include a carriage bolt, washer and nut, as shown in  FIG. 3 . One or both of the bores  58   a,    68   a  may be configured with a square cross-section to mate with a corresponding square cross-section on the carriage bolt of the clamping assembly  75 . Tightening the clamping assembly fixes the interdigitating engagement between the engagement surfaces  59 ,  69 . The clamping assembly may be spring biased so that when the assembly  75  is loosened the two components are pushed slightly apart so that the engagement faces are clear of each other to permit relative rotation of the components. As shown in  FIG. 4 , one of the bores  58   a  may include a countersink within which the head of the carriage bolt of the assembly  75  may reside. 
         [0020]    The engagement faces  59 ,  69  are configured to permit discrete gross or fine angular adjustments. In the present embodiment, the teeth or radial splines  59   a  ( FIG. 6 ) are configured and arranged to provide a five degree (5°) resolution, meaning that the relative angle between bail arms components can be adjusted at five degree increments. In one specific embodiment, the angles can range from 180° in which the bail arms  15 ,  18  are in a straight line, plus or minus 102.5° upward or downward. In other words, the head portions  58 ,  68  may be configured for a 205° range of relative angular motion between the components. As shown in  FIGS. 3 ,  6 , the inter-engagement features on the engagement faces  59 ,  69  may extend a full 360°, even though the relative range of motion may be limited to 205°. The full 360° engagement feature ensures a firm engagement between the bail arm members so that the relative angular positions do not slip when the bail arm is under load. In one embodiment, 72 teeth or splines are arranged around the circumference of the engagement faces  59 ,  69 . The teeth or splines can have a height of about 5/16 in. 
         [0021]    As shown in  FIG. 4 , the head portion  58 ,  68  of the components  54 ,  55  are sized so that when the two head portions are inter-engaged at the engagement faces  59 ,  69  the overall width is approximately equal to the width of the corresponding elongated bodies  57 ,  67 . Thus, in one embodiment the head portions  58 ,  68  each have a width of about ⅞ in. while the elongated bodies have a width of about 1 23/32 in., which is slightly less than the combined width of the inter-engaged head portions. The head portions are thus sized to provide a smooth transition with a corresponding bail arm, as shown in  FIG. 7 . 
         [0022]    The adjustable arm coupling  52  may be formed from a material strong enough to withstand the static and vibrational loads of the typical bail arm assembly. For instance, the upper and lower components  54 ,  55  of the coupling may be formed of the same material as the bail arms  15 ,  18 , such as aluminum or stainless steel. The components may be extruded, forged or cast, with appropriate machining. Alternatively, the components may be cast from a hard polymer or plastic material. The angle indicia on the angle indicators  60 ,  70  may be formed in the head portions  58 ,  68  or may be independently applied, such as a sticker or label. 
         [0023]    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.