Abstract:
A cargo tie down device includes a bracket for mounting on a vehicle such as a truck, trailer, rail car or the like. The bracket may be U-shaped and a hand ratchet may be mounted between the ends of the bracket to wind up a load strap on a spindle rotated by a pivotally mounted handle. A tension release mechanism operates independently of the load strap to safely release the load on the strap. In some embodiments, the bracket slides on a rail of the underside of the vehicle so it may be positioned at any of a series of locations on the vehicle. The device eliminates a conventional removable winch bar and thereby eliminates safety problems associated with winch bars.

Description:
[0001]    This application is based on U.S. Provisional Patent Application 61/634,721 filed Mar. 6, 2012, which is incorporated herein by reference and priority of which is claimed. 
     
    
       [0002]    This invention relates to a cargo tie down device or strap tightener for securing a load to a vehicle such as a trailer, truck or rail car. 
       BACKGROUND OF THE INVENTION 
       [0003]    A standard cargo tie down device used on trailers pulled by large trucks is mounted so that it has the ability to slide on a rail running front-to-rear on the bottom of one side of the trailer bed. The tie down device includes a bracket mounted on the rail for movement to a location adjacent the load to be secured to the trailer. The device includes an axle or spindle on which is wound a fabric strap that extends over the load and is secured to the opposite side of the trailer. One end of the axle has a gear and pawl mechanism preventing counterrotation of the axle so that rotation of the axle winds the strap onto the axle and tightens the strap over the load. The opposite end of the axle includes a pair of passages spaced at 90° for receiving a removable winch bar used to rotate the axle. 
         [0004]    This standard device has inherent safety problems when tightening the cargo strap. A winch bar or cheater is inserted into the axle opening and force is applied in a downward motion. The tip of the winch bar ought to be inserted completely through one of a pair of passages though the axle. Occasionally, operators insert the winch bar through only one hole to gain a leverage advantage. This can result in tip failure of the winch bar which can lead to injury. The winch bar typically has a curved end, meaning the winch bar can be inserted upside down and so positioned, is prone to failure potentially injuring the operator. Users of this style device occasionally misuse the winch bar because the holes in the axle are located at 90° intervals and, in the tightening operation, leverage is lost as the winch bar moves downwardly. Upon repositioning the bar in the next hole, leverage is often not gained due to the upward angle of the bar. Users often get under the winch bar and hang onto it using body weight to tighten the cargo strap, resulting in possible injury if the winch bar slips. 
         [0005]    This standard device also has safety problems when releasing tension in the cargo strap. A winch bar must be inserted into the axle opening and a force applied with one hand to increase tension in the strap and release the pawl from the gear. At the same time, the other hand is used to move the pawl away from the gear to allow counterrotation of the axle. When the user lets up on the winch bar, tension on the load strap causes the axle to counterrotate. Because of the tension in the load strap and the fact that the user can hold the winch bar with only one hand, the winch bar occasionally violently rotates and strikes the user. This problem is aggravated when the individual who tightened the strap is considerably stronger than the individual attempting to release tension in the strap. Serious injuries and death have occurred. 
         [0006]    Disclosures of some interest relative to this invention are found in U.S. Pat. Nos. 2,524,406; 5,282,706; 5,542,798; 6,047,989; 6,139,234; 6,457,701 and 7,909,553. 
       SUMMARY OF THE INVENTION 
       [0007]    The basic concept of this invention is to provide a cargo tie down device or strap tightener capable of being mounted on a vehicle frame to apply and release tension to a load strap in a safe manner without using a removable winch bar. By eliminating the removable winch bar, safety problems associated with the winch bar are also eliminated. 
         [0008]    To this end, in one embodiment, a commercially available hand ratchet device is secured to a bracket that slides on a conventional mounting rail of any suitable type below a trailer bed. A simple substitution of a conventional currently commercially available hand ratchet device for the conventional tie down device is not operable because typical commercially available hand ratchet devices are not sufficiently powerful to overcome frictional forces generated between the strap and the trailer and also provide sufficient tension to the load strap. In some embodiments, this is overcome by positioning the hand ratchet in a manner that is mainly inboard of the rub rail so the strap resides in a near vertical plane passing in a slot between the rub rail and the trailer body without rubbing against either. In this manner, frictional forces between the strap and the trailer body are reduced. 
         [0009]    Upon first disclosing to a group of experienced truckers, the concept of using a more-or-less conventional hand ratchet type tie down device in lieu of the conventional cheater bar operated tie down device, their opinion was universally that it could not be done. 
         [0010]    It is an object of this invention to provide an improved cargo tie down device that is safer in operation than the current industry standard. 
         [0011]    A further object of this invention is to provide an improved cargo tie down device or strap tightener that functions without use of a removable winch bar. 
         [0012]    A more specific object of this invention is to provide a cargo tie down device that incorporates commercially available components that can be conveniently replaced. 
         [0013]    These and other objects and advantages of this invention will become more apparent as this description proceeds, reference being made to the accompanying drawings and appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a view of a conventional cargo tie down device mounted on a trailer; 
           [0015]      FIG. 2  is a view of one side of an improved cargo tie down device and its connection to a rail on a vehicle illustrating the handle in a retracted or stowed position; 
           [0016]      FIG. 3  is a view of the opposite side of the device of  FIG. 2  illustrating the rail and vehicle in cross-section; 
           [0017]      FIG. 4  is an isometric view of a bracket used in the embodiment of  FIGS. 2-3 ; 
           [0018]      FIG. 5  is an isometric view of the device of  FIGS. 2-3  viewed from below a trailer body to which the device is attached, with the hand ratchet unfolded; 
           [0019]      FIG. 6  is a face on view of the handle assembly and part of the anchor link; 
           [0020]      FIG. 7  is a view similar to  FIG. 4  illustrating the handle in the middle of a tightening stroke; 
           [0021]      FIG. 8  is a face on view, similar to  FIG. 6  of the device of  FIG. 2  in the configuration of  FIG. 3 ; and 
           [0022]      FIG. 9  is a side view of an end of an anchor link connected to a handle assembly. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    Referring to  FIGS. 1 , there is illustrated a conventional cargo tie down device  10  mounted on a rail  12  on the underside of a trailer body  14 . The tie down device  10  includes a bracket  16  slidably received in the rail  12  so it may be positioned at suitable locations along the length of the trailer body  14 . The bracket  16  includes a pair of L-shaped shoulders  18  and a pair of depending side walls  20  journalling a tubular spindle or axle  22  which may include a central slot (not shown) into which is threaded a strap  24  so it can wind around the spindle  22 . The strap  24  extends upwardly through a gap  26  between the trailer body  14  and a rub rail  28 . An opposite end of the strap  22  is connected in any suitable manner (not shown) to the opposite side of the trailer. It will be seen that the spindle  22  is inboard of the gap  26  so the strap  24  defines an acute angle  30  relative to a horizontal plane  32  through the spindle  22 . In other words, a vertical plane  34  through the gap  26  is outboard of the spindle  22  and the strap  24  bends around the trailer body  14  on the inboard side of the gap  26 . 
         [0024]    The device  10  includes a gear  36  rigid with one end of the spindle  22  and a pawl  38  which allows rotation of the gear  36  in one direction and prevents rotation of the gear  36  in the opposite direction. A pair of passages (not shown) spaced at 90° extend through the opposite end (not shown) of the spindle  22  to allow a removable winch bar (not shown) to be used to rotate the spindle  22  to wind up the strap  24  thereby shortening the strap  24  and tightening the strap  24  on the load carried by the trailer body  14 . Those skilled in the art will recognize the device  10  and its operation as being exemplary of conventional cargo tie down devices of the type creating those types of safety problems discussed above. 
         [0025]    The following description of the preferred embodiments is not, nor is it intended to be, a description of all potential variations of this invention. It will be apparent that many modifications or alterations of various components may be made without departing from the invention and the scope of the invention as measured by the appended claims. 
         [0026]    Referring to  FIGS. 2-8 , there is illustrated one embodiment of an improved cargo tie down device or strap tightener  40  which may be attached to a load carrying vehicle in any suitable manner. The tie down device  40  can comprise, as major components, a bracket  42  and a hand ratchet  44 . In some embodiments, one or more rails  46  mounted on a trailer or vehicle body  48  provide a support for the bracket  42  and provide the advantage that the device  40  is adjustable along the length of the trailer body  48 . The rails  46  may accordingly be any of the various conventional rail designs or may be of new design. In some embodiments, the bracket  42  may be welded to the vehicle. The rails  46  can include a pair of L-shaped arms  50 ,  52  supporting the bracket  42 . The vehicle or trailer body  48  may include a rub rail  54  spaced from a body portion  56  and providing a gap  58  therebetween. 
         [0027]    As shown best in  FIG. 4 , the bracket  42  can comprise a pair of generally mirror image parallel side plates  60 ,  62  connected by a pair of rigid straps  64 ,  66 . The straps  64 ,  66  are selected to be of a size and shape to slide on the base of the arms  50 ,  52  and have sufficient capacity to withstand the load of the hand ratchet  44 . The bracket  42  can also include aligned passages  68 ,  70  for purposes more fully apparent hereinafter. The bracket  42  can be made of any suitable material but is typically of metal and may be stamped from a single blank. As shown best in  FIG. 5 , the trailer body  48  can include an end plate  72  preventing the tie down device  40  from sliding off the end off the end of the rail  46 . Among the purposes of the bracket  42  is to support the hand ratchet from the rail  46  and to position the hand ratchet  44  so its strap  74  extends upwardly through the gap  58  with minimal contact between the rub rail  54  or the trailer body  48  when the strap  74  is under load thereby reducing friction on the strap  74  and allowing an otherwise under powered tightener to adequately tighten the strap  74  and appropriately restrain cargo on the trailer body  48 . It will be apparent that conventional hand ratchets which can be used with the bracket  42  produce considerably less force than the conventional tie down device  10  because the cheater bar used with conventional devices may be 4-6′ long while the handle of conventional hand ratchets are on the order of 1′. Thus, the bracket  42  positions the hand ratchet  44  so a vertical plane  76  through the gap  58  is substantially tangent to a spindle  78  of the hand ratchet  44 . Viewed somewhat differently, the gap  58  provides a vertical plane A adjacent an inboard edge of the gap  58  and a vertical plane B adjacent an outboard edge of the gap  58  so all or part of the spindle  78  resides between the planes A, B. In addition, the handle assembly  80  resides wholly inboard of the rub rail  54  when the handle assembly  80  is in its stowed position shown in  FIGS. 2 and 3 . 
         [0028]    The hand ratchet  44  can be of a commercially available type such as any of models PT#A-2x27RFH5, PT#A-2x27RFH10, PT#A-3x27RFH-15, PT#A-4x27RFH20 available from Safe &#39;N Secure USA LP of Dallas, Tex. or similar devices that are available from other manufacturers such as Cargo Equipment Corp. of Elgin, Ill. Reference is made to publications of manufacturers for a more complete description of commercially available hand ratchets. Such hand ratchets  44  can include the strap  74 , the spindle  78  mounted for rotation in a handle assembly  80 , one or more gears  82 , first and second ratchet pawls  84 ,  86  cooperating with one or more of the gears  82 , an anchor link  88  and a tension release mechanism  90 . 
         [0029]    The strap  74  may be of any suitable type and is currently commercially available from a variety of suppliers. 
         [0030]    The spindle  78  can provide a central slot  92  to receive an end of the strap  74  to secure the strap  74  to the spindle  78 . In many embodiments, the spindle  78  is of two identical halves  94  spaced apart to provide the slot  92 . The spindle  78  extends through the aligned passages  68  and is accordingly mounted for rotation in order to wind up the strap  74 . The handle assembly  80  can be of any suitable type and can include a pair of arms  96  providing openings  98  at one end rotatably receiving the spindle  78 . The arms  96  can be connected by struts  100  to provide a unitary assembly. The handle assembly  80  is accordingly free to rotate about an axis  102  which passes through the spindle  78 . 
         [0031]    The first pawl  84  is mounted on the handle assembly  80  so oscillation of the handle assembly  80  rotates the gears  82  and tensions the strap  74 . The first pawl  84  can include a dog  104  engaging each of the gears  82 . The pawl  84  can be movably mounted on the handle assembly  80  in any suitable manner and spring biased toward the gears  82  as suggested by the arrow  106  in  FIG. 8 . Because of the curvature of the back of the individual teeth on the gears  82 , the pawl  84  rides over the back of the individual gear teeth in one direction of movement of the handle assembly  80  but engages the perpendicular face of the gear teeth in the opposition direction of movement of the handle assembly  80 . This causes rotation of the spindle  78  in one direction of rotation. 
         [0032]    The second pawl  86  is mounted for movement on the anchor link  88  and includes dogs  108  for engaging the gears  82  in a similar manner to the dogs  104  of the first pawl  84 . The pawl  86  can be biased by springs  110  toward the gears  82  so the dogs  108  hold the gears  82  and thus the spindle  78  from rotation in a tension relaxing direction. The pawls  84 ,  86  accordingly act to ratchet the spindle  78  in a strap tensioning direction upon rotation of the handle assembly  80  back and forth between the positions shown in  FIGS. 5 and 7  as suggested by the arrow  112 . 
         [0033]    In a conventional use of the conventional hand ratchet  44 , the anchor link  88  connects to a short length of strap (not shown) having a hook (not shown) on the end and the spindle  78  winds up the strap  74  to shorten the effective length of the strap. Instead, as used herein, the anchor link  88  is mounted on a strut  114  extending between the side walls  60 ,  62  of the bracket  42 . The strut  114  can comprise a bolt  116  having a nut  118  on one end and a head  120  on the other. The link  88  can comprise a pair of arms  122  having openings  124  at one end receiving the strut  114  and having openings  126  at the opposite end receiving the spindle  78 . The handle assembly  80  can accordingly be pivotally connected to the anchor link  88 . An important advantage of this construction is that a conventional hand ratchet  44  can be used and, when it fails or wears out, can be readily replaced by removing the bolt  116 , discarding the old hand ratchet and replacing it with a new one. It will also be seen that the bolt  116  binds the side walls  60 ,  62  together thereby strengthening the bracket  42 . 
         [0034]    The tension release mechanism  90  may be of any suitable type and can comprise a two part system of which a handle  128  on the first pawl is a part. Pulling on the handle  128  against the bias of a spring  130  biasing the pawl  84  toward the gears  82  disengages the dogs  104  from the gears  82 . In normal operation, the handle assembly  80  cannot be rotated counterclockwise from the position shown in  FIG. 7  because the pawl  84  contacts an abutment  132  ( FIG. 9 ) on the anchor link  88 . Pulling on the handle  128  raises the dogs  104  above the abutment  132  to allow further rotation of the handle assembly  80 . 
         [0035]    Release of the spindle  78  for movement in the tension relaxing direction does not occur upon disengagement of the pawl  84  because the pawl  86  remains in engagement with the gears  82  preventing rotation of the spindle  78 . The second part of the tension release mechanism  90  can be a device to move the pawl  86  out of engagement with the gears  82 , such as a cam  134  on the end of the handle arms  96 . Thus, activation of the cam  134  can be done by rotating the handle assembly  80  to the position shown by the axis  136  in  FIG. 7 . This causes the gears  82  to pass under the strap  64  of the bracket  42  so the cam  134  can abut an ear  138  of the pawl  86  ( FIG. 8 ) and push the pawl  86  out of engagement with the gears  82 . Disengagement of both pawls  84 ,  86  from the gears  82  removes any constraint against movement of the spindle  78 . This allows tension in the strap  74  to counterrotate the spindle  78  thereby relaxing tension in the strap  74 . All of this is done safely by manipulation of the handle assembly  80  and the handle  128  because the cheater bar of the prior art has been eliminated. 
         [0036]    Those skilled in the art will recognize the hand ratchet  44  to be typical of conventional hand ratchets used to tie down cargo. Conventional use of the hand ratchet  44  is to attach one strap to the anchor link  88  and wind another strap on the spindle  78 . The straps are connected, typically by hooks, to opposite sides of a trailer and the spindle  78  winds up one of the straps to tighten the load. 
         [0037]    As is apparent from  FIG. 3 , when there is no tension on the strap  74 , the hand ratchet  44  is free to pivot on the strut  114 . To prevent the hand ratchet  44  from swinging freely when not in use, a latch or keeper  140  may be provided. The latch  140  can comprise a pin  142  extending through the aligned openings  70  in the bracket  42  preventing downward pivotal movement of the hand ratchet  44 . The pin  142  can have a bent end  144  receiving a spring  146  and an opposite pivoted end  148 . When the latch  140  is inserted through the aligned openings  70  and the pivoted end  148  turned transverse to the pin  142 , the spring  146  holds the latch  140  securely in place. A tether (not shown) can connect the latch  140  to the device  40 . 
         [0038]    In some embodiments, a hand ratchet device is incorporated into a bracket that is able to slide on a conventional mounting rail where the hand ratchet device is a modified version of the hand ratchet shown in U.S. Pat. Nos. 5,282,706; 6,139,234 or other similar devices. In some embodiments, the bracket  42  or the hand ratchet  44  can be welded to a vehicle body. 
         [0039]    In use, the latch  140  is removed to allow movement of the handle assembly  80  and the strap  74  is unreeled and connected to an opposite side of the trailer body  48  over the top of a piece of cargo (not shown). The handle assembly  80  is then reciprocated between the positions of  FIGS. 2 and 7  to wind up the strap  74  on the spindle  78 . When the strap  74  is sufficiently tight, the handle assembly  80  is pushed to its retracted position as shown in  FIG. 2  and the latch  70  replaced thereby securing the cargo on the trailer body  48 . 
         [0040]    When it is desired to remove the cargo from the trailer body  48 , tension in the strap  74  is released. The latch  140  is removed and the handle assembly  80  moved to the solid line position shown in  FIG. 7 . The handle  128  is then pulled against the bias of the springs  130  thereby disengaging the pawl  84  from the gears  82 . Further movement of the handle assembly  80  to the position of the axis  136  in  FIG. 7  causes the cam  132  to push the ear  138  and thereby push the pawl  86  thereby disengaging the pawl  86  from the gears  82 . With both pawls  84 ,  86  disengaged from the gears  82 , the spindle  78  is free to rotate in a strap relaxing direction thereby removing tension from the strap  74 . The strap  74  can then be unhooked from the opposite side of the trailer body  48  and then rewound on the spindle  78 . The handle assembly  80  is folded back into the bracket  42  as shown in  FIG. 2  and the latch  140  replaced. 
         [0041]    Although this invention has been disclosed and described in its preferred forms with a certain degree of particularity, it is understood that the present disclosure of the preferred forms is only by way of example and that numerous changes in the combination and arrangement of parts, as well as the details of the components, may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.