Abstract:
A tensioning device for tie down applications in a utility market that includes a drive end and a cable output end to attach to a medium, item, or truck or trailer. The tensioning device creates more tension in the medium than is generally able to be applied by hand with ratchet straps or chains, which provides a more secure tie down of items in a utility application. The tensioning device includes a drive system that can be driven with standard power tools or hand tools to retract a cable. The tensioning device may be designed with or without a clutch feature. The clutch feature allows for a desired cable tension to be reached for each installation and provides feedback to the operator when the correct tension is reached. The tensioning device includes an external bracket or hook for easily attaching to an item, medium, or truck or trailer.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to tensioning devices, more particularly for devices used to tension a medium for use in utility markets, such as for tying down an off road vehicle on to a trailer. 
       BACKGROUND OF THE INVENTION 
       [0002]    Tensioning devices for utility applications currently used in the industry are generally hand operated commonly available devices that may not create sufficient tension in a cable, chain, or strap to properly secure the item that the user wishes to tie down. Tensioning devices commonly known in the art vary in design and the choice of tensioning devices commonly available are susceptible to damage by road hazards, animals, sun and ultraviolet deterioration. In many cases, the person installing the tensioning device is not able to create enough tension in the device to safely tie down or secure an object on to a trailer or truck. It is commonly known that to properly secure an item, such as an off road vehicle, on to a trailer or truck, the suspension of the off road vehicle must be compressed to a position that does not allow the off road vehicle to come loose when subjected to accelerations caused by the road. Others use commercially available ratchet straps made of fibers that are susceptible to damage and stretch over time. Furthermore, ratchet straps are difficult to install by hand to safe tension for securing an item on a trailer, or for other utility applications. 
         [0003]    There is therefore a need in the art for a tensioning device for utility applications that is easy to install and generates sufficient tension to properly secure an item to a trailer or on to a truck. The applications are many for such a tensioning device, and the application of securing an off road vehicle or snowmobile to a trailer or truck is just one example. 
       SUMMARY OF THE INVENTION 
       [0004]    In one aspect there is disclosed a tensioning device for utility applications that includes a mechanism to provide tension in a cable utilizing a common drive feature and a threaded element. 
         [0005]    More particularly, the threaded elements are disposed within a tube or housing wherein rotation of a threaded tube draws a cable into the tensioning device to create tension in a medium used in a utility application, such as holding an off road vehicle on to a trailer or truck. 
         [0006]    The drive insert is attached to the end of a cable and is installed inside of a threaded tube. The drive insert may be located on the cable with clearance to the cable and an additional stop added to the cable to react against the drive insert, if desired. The drive insert may also include an area for crimping on to the cable. 
         [0007]    The threaded tube is disposed within an outer tube. The outer tube does not rotate during installation and it provides an attachment point to a bracket or other medium for attaching to a point, such as a trailer when holding down an off road vehicle on to a trailer. 
         [0008]    The outer tube may have a variety of designs for attachment. In one embodiment, a hook may be attached to or may be part of the outer tube or housing to provide the attachment to the medium or bracket. 
         [0009]    The outer tube may be painted or otherwise coated for decorative purposes or for corrosion resistance. Soft coatings for noise dampening may also be used. 
         [0010]    A drive member is installed at one end of the threaded tube to allow the threaded tube to be rotated inside the outer tube to draw the cable in. In one aspect, the drive member may be rigidly attached to the threaded tube to drive it rotationally. In another aspect, the drive member may be installed in a manner that acts as a clutch to prevent overload of the cable and provide feedback to the person installing the tensioning device that it is installed to the proper cable tension. 
         [0011]    The clutched drive member design may include one or more clutch pins to match with radiused geometry inside the end of the threaded tube and have a spring to provide force holding the one or more pins into the radiused geometry in the threaded tube. Those skilled in the art recognize that a variety of designs may be used to act as a clutch on the drive mechanism of the tensioning device. 
         [0012]    The clutch may be designed in a manner that is asymmetrical to protect against over travel in the cable release direction. In one aspect, the geometry on the inside of the end of the threaded tube may have radiused geometry where one side of the radiused geometry is shallower than the other side, allowing the clutch pins to disengage the radiused geometry at a lower torque in the release direction. 
         [0013]    A retaining ring may be used to retain the threaded tube and drive member into the outer tube to ensure the assembly remains together, even when the tensioning device is loosened causing the drive insert to contact the inside of the outer tube or housing at the cable exit end. In the design incorporating a clutch, the retaining ring may provide a stop for the drive member and clutch assembly to ensure that the components of the clutch stay engaged. Those skilled in the art recognize a variety of retainer designs may be used to accomplish this design purpose. 
         [0014]    A cable bushing may be installed in the end of the outer tube opposite the drive member. The cable bushing provides support for the cable as it exits the tensioning device, as the exit direction of the cable may vary. In one aspect, the outer tube may be designed as a single piece and the geometry of the cable exit may be part of this single piece outer housing. 
         [0015]    The cable bushing may be pressed or crimped into the outer tube to secure it in place and seal out water. The cable bushing may also be coated with a sealant or adhesive to assist in sealing the cable bushing to the tube. The cable bushing may also include an internal groove for the purpose of installing a seal, such as an o-ring, to seal the cable exit from contaminants. 
         [0016]    The cable may include a cable hook to be attached to a chain or other medium to be used in a utility application. Those skilled in the art recognize that the cable hook may have many different designs and methods of attachment to the cable. 
         [0017]    A thrust washer may be installed inside the outer tube to provide a smooth and flat surface for the threaded tube to rotate against while cable tension is increasing. A bearing with roller elements may also be used. 
         [0018]    An insert for anti-rotation may be installed inside the threaded tube to prevent the drive insert from rotating as the threaded tube is rotated, thus retracting the cable and creating tension for installation of tensioning device in a utility application. 
         [0019]    Those skilled in the art recognize that many designs may be used to accomplish these purposes and the above summary is for illustrative purposes of one embodiment of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1A  is an exploded isometric view of one embodiment of a tensioning device for utility applications; 
           [0021]      FIG. 1B  is a top and sectional view of one embodiment of a tensioning device for utility applications; 
           [0022]      FIG. 1C  is an isometric view of one embodiment of a tensioning device for utility applications; 
           [0023]      FIG. 1D  is a side and sectional view of one embodiment of a tensioning device for utility applications; 
           [0024]      FIG. 1E  is an exploded isometric view of one embodiment of a tensioning device including a clutch for utility applications; 
           [0025]      FIG. 1F  is a top and sectional view of one embodiment of a tensioning device including a clutch for utility applications; 
           [0026]      FIG. 1G  is a side and sectional view of one embodiment of a tensioning device including a clutch for utility applications; 
           [0027]      FIG. 2  is an assembled view illustrating the placement of a tensioning device on a trailer for holding down an off road vehicle; 
           [0028]      FIG. 3  is a perspective view of another embodiment including a center hex and clutch for utility applications; 
           [0029]      FIG. 4  is a top view of the embodiment of  FIG. 3 ; 
           [0030]      FIG. 5  is a sectional view along the line A-A of  FIG. 4 ; 
           [0031]      FIG. 6  is a sectional view along the line B-B of  FIG. 5 ; 
           [0032]      FIG. 7  is a perspective view of the embodiment of  FIG. 3  assembled; 
           [0033]      FIG. 8  is a perspective view of the threaded tube and drive insert showing threads. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0034]    Referring to the Figures, there is shown embodiments of a tensioning device  10  for utility applications. The tensioning device  10  may include an outer tube  12  and a cable  14 . The tensioning device  10  may also include a threaded tube  16  which rotates to retract the cable  14  to a desired tension. 
         [0035]    As seen in  FIGS. 1A-D , the threaded tube  16  may include threads  18  formed on an inner diameter of the threaded tube  16 . The threaded tube  16  may also include unthreaded portions  20  formed on one or both ends of the threaded tube  16  to act as protection against over-travel of the tensioning device  10 . In one aspect, the threaded tube  16  may include a radiused geometry  22  on the end proximate a drive member  24 . 
         [0036]    The cable  14  may include an attachment structure such as a cable hook  26  to attach the tensioning device  10  to a medium or an item to be tied down. The cable hook  26  may be crimped or cast on to the cable  14 . Those skilled in the art recognize a variety of hook designs may be used to accomplish this attachment. 
         [0037]    A drive insert  28  may be attached to the end of the cable  14  opposite the cable hook  26 . The drive insert  28  may be threaded  18  to match the threads  18  of the threaded tube  16 . The drive insert  28  may have one or more holes  29  formed therein allowing passage of an anti-rotation member  30 . The drive insert  28  may also include a reduced diameter section  32  to allow for crimping to the cable  14 . 
         [0038]    Thrust washers  34  may be positioned so that the threaded tube  16  may have a bearing surface to rotate against that is smooth and flat. The thrust washers  34  may include geometry for clearance of the anti-rotation member  30  relative to the thrust washer  34 . Those skilled in the art recognize that a ball or roller bearing may be installed in place of the thrust washers  34 . 
         [0039]    A retaining ring  36  may be installed within the outer tube  12  adjacent the thrust washer  34  to prevent the threaded tube  16  from translating inside the outer tube  12  as cable tension is increased. 
         [0040]    As stated above, anti-rotation members  30  may be installed within the outer tube  12  either by press fit or some other method to prevent the drive insert  28  from rotating as the threaded tube  16  is rotated. The anti-rotation members  30  may be positioned inside the threaded tube  16  and include extensions which pass through holes  29  in the drive insert  28 . In one aspect, the anti-rotation members  30  may include three members; however, those skilled in the art recognize that a variety of designs would function to prevent rotation of the drive insert  28 . 
         [0041]    A drive member  24  may be used to rotate the threaded tube  16  using a cordless drill or other hand tools. In one aspect, the drive member  24  may include an external hexagonal structure  38  to rotate the threaded tube  16 . Those skilled in the art recognize that a variety of shapes and configurations may be used as a drive feature to rotate the threaded tube  16  for operation of the tensioning device  10 . 
         [0042]    A drive member  24  may be rotated by hand or power tools. When rotated, the drive member  24  may rotate the threaded tube  16 . As the threaded tube  16  is rotated, the threads  18  on the inside of the threaded tube  16  engage the external threads on the drive insert  28 . The drive insert  28  is restricted from rotation by the anti-rotation members  30 , allowing the drive insert to move upward on the threads  18  of the threaded tube  16  toward the drive member  24  and retracting the cable  14  and creating tension. 
         [0043]    In one aspect, the drive member  24  may be directly and rigidly attached to the threaded tube  16  allowing the threaded tube  16  to be rotated to retract the cable  14  and provide tension. In another aspect, the drive member  24  may be integral with the threaded tube  16  as one component. 
         [0044]    Alternatively, the drive member  24  may be coupled to the threaded tube  16  in a manner that allows slippage when proper tension is reached thus acting as a clutch. As shown in  FIGS. 1E-G , in this embodiment, the drive member  24  may include a slot  40  that receives clutch pins  42 . The clutch pins  42  may pass through the slot  40  and be retained in the slot  40 . The threaded tube  16  may include radiused slots  46  to accept the clutch pins  42 . Those skilled in the art recognize that one or more pins  42  may be utilized. 
         [0045]    A clutch spring  44  may be positioned between two clutch pins  42  inside the slot  40  of the drive member  24  to hold the clutch pin  42  into radiused slots  46  formed in the threaded tube  16  until the desired torque is obtained. The movement of the clutch pin  42  into and out of the radiused slots  46  of the threaded tube  16  may provide audible and/or tactile feedback that proper cable tension has been obtained. 
         [0046]    The cable  14  force may be directly proportional to the input torque applied to the drive member  24  allowing for control of the cable tension. Various numbers and shapes of the clutch components such as the slots  46  and pins  42  can be controlled based on the design of the clutch and threaded elements. Those skilled in the art will recognize that various designs may be utilized to allow slippage in the mechanism to prevent excessive cable  14  force. 
         [0047]    Alternatively, the radiused slots  46  may have an asymmetrical design. In one aspect, the radiused slots  46  may have a geometry wherein the depth of the radiused slot  46  is less on one side than the other. The reduced depth of the radiused slot  46  on one side may allow the clutch pins  42  to overcome the clutch spring  44  and travel out of the radiused slot  46  at a lower torque in one direction. As illustrated, the clutch pins  42  may travel out of the radiused slots  46  in the direction where the tensioning device is extending the cable  14  to prevent the tensioning device  10  from becoming locked if it were over-released. 
         [0048]    In one aspect, a locking cap  48  may be placed over the outer tube  12  and the drive member  24 . The locking cap  48 , when installed, prevents access to the drive member  24  so that the tensioning device  10  may not be loosened without removing the locking cap  48 . The locking cap  48  may include a keyed actuator. When the locking cap  48  is installed over the outer tube  12  and drive member  24  it engages a locking groove  50  requiring actuation of a key tumbler to remove the locking cap  48  from the outer tube  12 . 
         [0049]    In another alternative embodiment shown in  FIGS. 3-7 , as with the embodiment disclosed in  FIGS. 1E-G , the drive member  24  may be coupled to the threaded tube  16  in a manner that allows slippage when proper tension is reached thus acting as a clutch. In this embodiment, the drive member  24  may include a slot  40  that receives clutch pins  42 . The clutch pins  42  may pass through the slot  40  and be retained in the slot  40 . The threaded tube  16  may include radiused slots  46  to accept the clutch pins  42 . Those skilled in the art recognize that one or more pins  42  may be utilized. In the depicted embodiment two clutch pins  42  are provided and are spaced and positioned relative to each other by a pin  43 . 
         [0050]    A clutch spring  44  may be positioned about the pin  43  and between two clutch pins  42  inside the slot  40  of the drive member  24  to hold the clutch pins  42  into radiused slots  46  formed in the threaded tube  16  until the desired torque is obtained. The movement of the clutch pin  42  into and out of the radiused slots  46  of the threaded tube  16  may provide audible and/or tactile feedback that proper cable tension has been obtained. 
         [0051]    The cable  14  force may be directly proportional to the input torque applied to the drive member  24  allowing for control of the cable tension. Various numbers and shapes of the clutch components such as the slots  46  and pins  42  can be controlled based on the design of the clutch and threaded elements. Those skilled in the art will recognize that various designs may be utilized to allow slippage in the mechanism to prevent excessive cable  14  force. 
         [0052]    Alternatively, the radiused slots  46  may have an asymmetrical design. In one aspect, the radiused slots  46  may have a geometry wherein the depth of the radiused slot  46  is less on one side than the other. The reduced depth of the radiused slot  46  on one side may allow the clutch pins  42  to overcome the clutch spring  44  and travel out of the radiused slot  46  at a lower torque in one direction. As illustrated, the clutch pins  42  may travel out of the radiused slots  46  in the direction where the tensioning device is extending the cable  14  to prevent the tensioning device  10  from becoming locked if it were over-released. 
         [0053]    Again referring to  FIGS. 3-7  the anti-rotation members  30  previously described above may have another shape and structure. In the depicted embodiment, the anti-rotation member  30  may be a hexagonal tube  50  or alternatively could be square, triangle, octagon, etc that may be installed within the outer tube  12  either by welding, gluing or otherwise attaching to prevent the drive insert  28  from rotating as the threaded tube  16  is rotated. In one aspect, the hexagonal tube  50  includes slots  55  formed longitudinally along a portion of its length to allow connection of the drive insert  28  with the cable  14  and to allow the drive insert  28  to travel about the hexagonal tube  50  within the threaded tube  16 . 
         [0054]    The drive insert  28  in the depicted embodiment of  FIGS. 3-7  includes an annular body  57  that may be attached to the end of the cable  14  opposite the cable hook  26 . The drive insert  28  may be threaded on an outer surface to match the threads  18  of the threaded tube  16 . The drive insert  28  may have a slot  59  formed therein that corresponds to the hexagonal tube  50 . Additionally the drive insert  28  may include an axial slot  61  that passes through the annular body  57 . A pin  63  may pass through the axial slot  61  attaching the cable  14  to the drive insert  28 . In one aspect, the cable  14  is connected to a cable interface  65 . The cable interface  65  includes an axial slot  67  such that when assembled the pin  63  passes through the axial slot  61  of the drive insert  28  and the axial slot  67  of the interface  65  thereby joining the components. 
         [0055]    Thrust washers  34  may be positioned so that the threaded tube  16  may have a bearing surface to rotate against that is smooth and flat. Those skilled in the art recognize that a ball or roller bearing may be installed in place of the thrust washers  34 . 
         [0056]    A spacer  69  may be positioned between the drive insert  28  and clutch pins  42 . In this manner an axial load is not applied to the clutch pins  42  and spring  44  when the tensioning device  10  is actuated to release a load from the tensioning device  10 . 
         [0057]    Referring to  FIG. 2 , there is shown the cable tensioning device  10  for holding down an off road vehicle  31  to a trailer  32  or truck bed. The tensioning device  10  is attached to a medium, such as a chain or strap  35 . The chain or strap  35  may be attached to the off road vehicle  31  on one end or to the trailer  32 . The other end of the tensioning device  10  may be attached to the trailer  32  or to a chain or strap  35  that is attached to the off road vehicle  31 . 
         [0058]    For safe attachment of an off road vehicle  31  to a trailer  32 , the suspension of the off road vehicle  31  must be compressed far enough that vertical and horizontal accelerations due to towing the trailer  32  on a road or trail will not cause the off road vehicle  31  to bounce far enough to loosen the straps or chains  35 . 
         [0059]    When the tensioning device  10  is actuated and the cable  14  is drawn into the device, the tension in the chain  35  is increased to compress the off road vehicle  31  suspension sufficiently to secure it to the trailer  32 . 
         [0060]    The invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than limitation. Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described.