Abstract:
A retractable tie down for tying a work vehicle down to a cargo vehicle is disclosed, the tie down including a retractor assembly fixed to the outer surface of a work vehicle; a belt with one end connected to the retractor assembly; and a coupling connected to the other end of the belt, wherein the belt has a length sufficient to reach the cargo vehicle.

Description:
FIELD OF THE INVENTION  
       [0001]     The invention relates generally to work vehicles, and more particularly to tractors or work vehicles that are transported on trailers.  
       BACKGROUND OF THE INVENTION  
       [0002]     Skid steer loaders, tractors and other work vehicles typically work on job sites that are remotely located from the vehicle storage location or garage. The vehicles are loaded onto a trailer or truck bed for transportation between the storage location and the work site. Before transportation, one or more vehicles are driven onto the trailer and firmly secured to the trailer. A secure load is necessary in order that the vehicle does not fall off the trailer during transportation.  
         [0003]     Securing vehicles to a trailer is usually performed with chains, and the process requires several steps. The loose chains are stored in a box when no load is being transported. The chains are removed from the storage box, untangled, and cleaned of mud and debris. One end of a chain is attached to the trailer. The chain is then pulled though openings in the chassis of the vehicle and the other end of the chain is attached to the trailer. The chain may have one or more hooks to make it easier to fasten them to the trailer. The chain is then tightened using a come-along, winch or other chain-tightening device. This process is repeated for each securing point. If the chains are tangled and mud-clogged, the load securing process is delayed. The chain attaching and tightening phases are also time-consuming, as chains slip during attachment and they are heavy and awkward to handle and thread through openings in the chassis of the vehicle.  
         [0004]     The number of securing points is determined by the load stability, which is further influenced by the height, weight, and footprint of the load on the trailer. The transportation laws of the state or country may also proscribe the number and type of securing methods and points that are used. Currently, securing a load to at least four points is common. As more securing points are used, the time required for the operator to fully secure the load increases. Also, with more securing points required comes the need to carry and store more chains for attaching the vehicle.  
         [0005]     Trailers typically have many locations along their sides to which chains may be secured. There are far fewer potential locations on the work vehicle itself around or through which chains may be looped or threaded. A typical work vehicle has only a few attachment points, and these are typically disposed low on the vehicle chassis around the tires. Often, there is no attachment point, or an attachment point that is not convenient, forcing the operators to, wrap the chains around vehicle axles, frame members or bumpers.  
         [0006]     Attachment points on work vehicles are typically covered with mud, ice and other debris after a long work day. They have to be cleaned before chains are attached to or threaded through them. The operator typically gets quite dirty when threading the chains to attachment points or wrapping them around frame members. Worse, if no attachment points are within reach, or at the proper locations on the vehicle to secure the vehicle well, the operator must climb onto, over, or under the vehicle to secure the chains.  
         [0007]     The chains are typically tightened by a winch or come along with one end fixed to the rail on the side of the trailer and the other end extending to the end of the chain that was just passed through the attachment point on the work vehicle. In another arrangement, a retractable device is mounted to the bed of a truck or trailer, and a strap is extended with a hook at the end that is attached to the trailer&#39;s cargo. The strap is tensioned by a tensioning mechanism located partway along the belt. This arrangement requires that the operator pull the belt tight and hold it while locking the tensioning device. Due to its location on the bed of the truck or trailer, the retractable device is prone to dirt and ice encrustation.  
         [0008]     What is needed is a process of securing a work vehicle to a trailer that requires minimal steps. What is also needed is a retractable tie down mechanism that does not require looping or attaching to the vehicle during the load securing process. What is further needed is a retractable mechanism that is mounted to the vehicle, and is self-retracting such that the operator need only pull a hook out from the vehicle and attach the hook to the trailer.  
       SUMMARY OF THE INVENTION  
       [0009]     In accordance with a first aspect of the invention, a retractable tie down is provided that includes a retractor assembly, a belt including a first end and a second end, wherein the first end is connected to the retractor assembly, and a coupling connected to the second end, wherein the retractor assembly is fixed to a work vehicle.  
         [0010]     The belt may be selected from a group consisting of a fabric strap, a metal strap, a chain, and a cable. The retractor assembly may be spring loaded to retract the belt into the retractor assembly. The retractor assembly may further comprise a manual lock, the lock including a lock position and an unlock position, wherein in the lock position the lock prevents the belt from further extension from the retractor assembly, wherein in the unlock position the lock permits the belt to further extend from the retractor assembly. The retractor assembly may further comprise an internal locking device, wherein the internal locking device is configured to automatically engage the belt to prevent further extension of the belt, after the belt is extended and extension has been stopped by the operator. The retractor assembly may further comprise a manual release, the release including a release position and an unrelease position, wherein in the release position the internal locking device is disengaged from the belt, wherein in the unrelease position the internal locking device is not disengaged from the belt. The manual release may be biased to remain in the unrelease position. The retractable tie down may further comprise a cover, wherein the cover is pivotally attached to the retractor assembly, wherein the cover surrounds the retractor assembly. The cover may be spring loaded. The cover may have an open position and a closed position, wherein in the open position the operator can access the retractor assembly, the belt and the coupling, wherein in the closed position the operator can access the belt and the coupling, and wherein the cover is spring loaded and biased to remain in the closed position. The retractor assembly may be removably fixed to the work vehicle with at least one threaded fastener.  
         [0011]     In accordance with a second aspect of the invention a method for securing a work vehicle onto a trailer using a plurality of retractable tie downs, wherein the plurality of tie downs are fixed to the work vehicle, the method comprising the steps of (a) driving the vehicle onto the trailer, (b) unreeling a free end of one or more tie downs from the work vehicle, (c) attaching the free end of one or more tie downs to the trailer and (d) tensioning one or more tie downs.  
         [0012]     The work vehicle may be a skid steer loader including towers and loader arms. One or more tie downs may be fixed to one or more towers. One or more tie downs may be fixed to one or more loader arms. Step (d) may include a step of driving the vehicle forward or backward until the tie downs are tense. Step (d) may include a step of raising or lowering the loader arms until the tie downs are tense. The tie down may include a manual release and step (d) may include steps of activating the manual release, and automatically retracting the free end of the tie down onto a reel by a spring force. The tie down may include a manual release and step (b) may include steps of activating the manual release, and pulling a free end from a reel under spring tension. The tie down may include a manual lock, and step (c) may include a step of activating the manual lock to prohibit the free end from further extension.  
         [0013]     In accordance with the third aspect of the invention, a retractable tie down for securely tying a work vehicle down to a cargo vehicle for transport, is provided the work vehicle being supportable on and transportable by the cargo vehicle, the tie down including: means for securing the work vehicle to the cargo vehicle; means for retracting the securing means, the retracting means being coupled to the work vehicle; and means for coupling the securing means to the cargo vehicle; wherein the means for retracting is fixed to an outer surface of the work vehicle and the means for securing has a length sufficient to reach the cargo vehicle.  
         [0014]     The means for securing may be selected from a group consisting of a fabric strap, a chain and a cable. The means for retracting may include a means for coiling the securing means; and a tensioning means coupled to the coiling means to retract the securing means into the retracting means. The retracting means may also include a means for locking the securing means, the locking means being movable between a lock position and an unlock position; wherein in the lock position the locking means is configured to prevent the securing means from further extension from the retracting means; and wherein in the unlock position the locking means permits the securing means to further extend from the retracting means. The retracting means may also include a means for automatically locking the securing means; wherein the automatic locking means may be configured to automatically engage the securing means to prevent further extension of the securing means, after the operator (1) initially extends the securing means, and (2) subsequently stops extending the securing means. the retracting means may further include a means for releasing the securing means, the releasing means being movable between a release position and an unrelease position; wherein in the release position the automatic locking means is disengaged from the securing means; and wherein in the unrelease position the automatic locking means is not disengaged from the securing means. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is a view of a work vehicle having retractable tie downs in accordance with the present invention, showing the work vehicle on a trailer.  
         [0016]      FIG. 2  is a perspective view of a retractable tie down, fixed to the side of the work vehicle, with its cover closed.  
         [0017]      FIG. 3  is a side view of the retractable tie down of  FIG. 2  with the cover raised.  
         [0018]      FIG. 4  is a bottom view of the retractable tie down of  FIGS. 2-3 .  
         [0019]      FIG. 5  is a flow chart showing a method of using the tie downs to secure a work vehicle to a cargo vehicle in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0020]      FIG. 1  shows a cargo vehicle  100  that comprises a tractor  102  coupled to a trailer  104 . A work vehicle  106  (here shown as a skid steer loader) is mounted on trailer  104  for transport. Ramps  108  are coupled to the end of trailer  104 . They are supported by the trailer at one end and are supported by the ground at the other end. They support work vehicle  106  as it is driven on to trailer  104 .  
         [0021]     Cargo vehicle  100  is configured to carry and transport work vehicle  106  from one job site to another, typically over the open road. In the preferred embodiment, shown here, cargo vehicle  100  is a tractor/trailer combination.  
         [0022]     Trailer  104  has an elongate bed and a plurality of cargo securing fixtures  110  that are fixed on either side of the trailer bed. A series of these fixtures  110  extend the length of the bed on either side. In addition, several fixtures (not shown) are disposed on the upper surface of the flat bed of trailer  104 . Fixtures  110  are preferably slots, as shown here.  
         [0023]     Skid steer loader  106  includes a chassis  112 , two left and two right wheels  114  supporting the chassis, left and right tracks  116  that wrap around the left and right wheels, left and right loader arms  118  that are pivotally coupled to the chassis, a bucket  120  that is pivotally coupled to the loader arms, and left and right loader arm lift cylinders  122  coupled to the loader arms.  
         [0024]     Skid steer loader  106  also includes left front and right front retractable tie downs  124 , and left rear and right rear retractable tie downs  126 .  
         [0025]     Chassis  112  includes two towers, posts or uprights  128  that are disposed on either side of, and at the rear of, operator compartment  130 . Chassis  112  extends the length of loader  106  and provides a base on which the loader arms  118  and wheels  114  are mounted.  
         [0026]     Two wheels  114  are disposed on either side of the vehicle in a fore-and-aft relation. Only the two wheels on the left side are illustrated in  FIG. 1 . The wheels on the right side of the vehicle are disposed identically but in mirror relation, since skid steer loader  114  is symmetric about its longitudinal axis.  
         [0027]     Tracks  116  are continuous loops of metal links or are elastomeric belts that extend around the periphery of the wheels on each side of the vehicle  106 .  
         [0028]     Two loader arms  118  are disposed on either side of the vehicle  106 , and are pivotally coupled to towers  128  at their rear ends. The front ends of loader arms  118  are coupled to bucket  120 . Only the left loader arm  118  is shown in  FIG. 1 . The right loader arm is identically arranged but in mirror relation.  
         [0029]     Bucket  120  is pivotally coupled to the loader arms  118  to be raised and lowered whenever the loader arms  118  are raised and lowered.  
         [0030]     Loader arm lift cylinders  122  are hydraulic cylinders that are coupled to and between chassis  112  and loader arms  118  to lift the front of loader arms  118  with respect to the chassis  112 . Only the left side loader arm cylinder  122  is shown. The right side loader arm cylinder  122  is identically arranged, but in mirror relation. Each cylinder  122  is pivotally connected at one end to the chassis  112  and is pivotally connected at the other end to a loader arm  118 . Whenever the cylinders  122  extend and retract, the forward ends of the loader arms  118  raise and lower with respect to the chassis  112 .  
         [0031]     Tie downs  124 ,  126  are configured to secure skid steer loader  106  to the trailer  104  for transport over the road. Left front and right front tie downs  124  are fixed to the front of the left and right loader arms  118 , respectively. Left rear and right rear tie downs  126  are fixed to left and right towers  128 , respectively.  
         [0032]     Only the left side tie downs are illustrated herein. The right side tie downs and the left side tie downs are identically constructed and arranged. The only difference between the left side and right side tie downs is that the right side tie downs are disposed on the right side of the vehicle in mirror relation to the left side tie downs.  
         [0033]     Tie downs  124 ,  126  are identically constructed and are shown in more detail in  FIGS. 2-4 . Each tie down  124 ,  126  includes a retractable belt  132  that is configured to attach at its free, lower end to trailer  104  of cargo vehicle  100 . The free end of belt  132  includes a coupling  134  that is configured to be fixed to cargo securing fixtures  110  of trailer  104 .  
         [0034]     Tie downs  124 ,  126  are preferably located at the four corners of vehicle  106  as shown here. A similar placement will work for many four or six wheel work vehicles, such as tractors, backhoes, trucks, and off-road recreational vehicles. This placement allows a wide separation between the cargo securing fixtures  110  to which the tie downs are attached. By attaching a vehicle to widely separated cargo securing fixtures  110 , the vehicle  106  travels better over the road and is less likely to shift unexpectedly.  
         [0035]     Tie downs  124 ,  126  are preferably located high on the vehicle, as shown herein. A high position keeps them clean, and makes it easy for the operator to reach the belts when he is attaching a vehicle  106  to trailer  104 .  
         [0036]      FIGS. 2-4  illustrate a preferred embodiment of tie downs  124 ,  126 . The particular tie down illustrated in  FIGS. 2-4  is left front tie down  124 , which is also shown in  FIG. 1 . Since all of the tie downs on the vehicle are constructed identically to left front tie down  124 , they are not separately described herein. The description of left front tie down  124  applies equally to all the other tie downs  124 ,  126  on vehicle  106 .  
         [0037]     Left front tie down  124  include a mounting plate  136  fixed to skid steer vehicle  106 , a retractor assembly  138  fixed to the mounting plate, a belt  132  fixed to (and extending from) retractor assembly  138  at one end, and coupling  134  that is fixed to the free end  140  of the belt. Tie down  124  also includes a cover  142  that extends around and encloses retractor assembly  138 , and a fastener  144  for attaching tie down  124  to skid steer vehicle  106 .  
         [0038]     Mounting plate  136  is the base to which the other components of tie down  124  are attached. Plate  136  has a through hole  146  at its upper end. Fastener  144  extends through hole  146  and is attached to left loader arm  118 . Fastener  144  is preferably a bolt, and left loader arm  118  preferably has a threaded mating hole  148  to which fastener  144  is attached. In the case of rear tie downs  126 , fastener  144  is attached to the towers at the rear of the skid steer loader.  
         [0039]     Retractor assembly  138  is fixed to mounting plate  136  and is configured to selectively extend, retract, and store belt  132 .  
         [0040]     Retractor assembly  138  includes a housing  152  that supports the other components of assembly  138 , a spindle  154  that is fixed to housing  152 , a reel  156  that is supported for rotation on spindle  154 , a retracting device  158  coupled to reel  156  to tension and wind belt  132  on reel  156 , a manual lock  160  coupled to housing  152  to prevent the extension or retraction of belt  132 , an automatic lock  162  for preventing the extension of belt  132 , and a manual release  164  for releasing automatic lock  160 .  
         [0041]     Housing  152  of retractor assembly  138  is fixed to mounting plate  136 . The other components of retractor assembly  138  are attached to housing  152 .  
         [0042]     Spindle  154  extends across the inside of the housing  152  and is fixed at its ends to housing  152 . Spindle  154  extends through the hollow core of reel  156  and supports the reel for free rotation within the housing.  
         [0043]     Reel  156  is mounted for rotation on the spindle  154 . Reel  156  rotates on spindle  154  to wind and unwind belt  132 . Reel  156  has a slot  166  to which end  150  of belt  132  is fixed. One end of reel  146  has first teeth  168  that engage manual lock  160  when it is moved to its lock position, and second teeth  170  on the other end of the reel that engage automatic lock  162 .  
         [0044]     Retracting device  158  is provided to wind and tension belt  132  onto reel  156 , thereby retracting belt  132  into retractor assembly  138 . Retracting device  158  includes a spring  172  mounted on the spindle. Spring  172  keeps tension on reel  156 , which, in turn, tensions belt  132 . One end of spring  172  is connected to the side of the reel  156 . The other end of the spring is connected to housing  152 . A suitable alternative retracting device may be seen in U.S. Pat. No. 4,842,458, which is incorporated herein by reference for all that it teaches regarding an alternative retracting device. Spring  172  will retract belt  132  into the retractor assembly  138  if it is not otherwise prevented, such as by the operator, by manual lock  160  or by automatic lock  162 .  
         [0045]     Manual lock  160  is provided to lock belt  132 . Manual lock  160  locks reel  156  in place, which prevents belt  132  from being in either withdrawn from or rewound into retractor assembly  138 . Manual lock  160  has two positions, and unlock position and a lock position. When manual lock  160  is pressed toward reel  156 , it engages first teeth  168  on reel  156 . In this position, reel  156  cannot rotate about spindle  154 . When manual lock  160  is withdrawn from reel  156 , it disengages with first teeth  168  and permits reel  156  to rotate.  
         [0046]     Automatic lock  162  is contained inside the housing  152  and is configured to automatically lock belt  132  when belt  132  is extended and the belt&#39;s extension is stopped. In use, the operator extends belt  132  to a preferred length, attaches coupling  134  to a cargo securing fixture  110  on trailer  104 , then allows or otherwise causes retracting device  158  to take the slack out of belt  132 , reeling any excess belt length back into retractor assembly  138 . Automatic lock  162 , functions like an automobile seat belt, locking belt  132  when it begins to retract and preventing it from being extended until manual release  164  is activated. An alternative automatic lock that may be used in place of automatic lock  162  is shown in U.S. Pat. No. 2,825,581, which is incorporated by reference herein for all that it teaches regarding an alternative automatic lock.  
         [0047]     Manual release  164  is provided to release automatic lock  162  and belt  132  when it is moved to its release position. Manual release  164  permits belt  132  to be withdrawn from retractor assembly  138 . Manual release  164  has a release position and an unrelease position. In the other release position it permits automatic lock  162  to again engage belt  132 .  
         [0048]     In use, when the operator pushes manual release  164  to its release position, manual release  164  responsively defeats, overrides and disengages automatic lock  162 , permitting the operator to further extend belt  132  from retractor assembly  138  typically by pulling on belt  132  against the tension of the spring. When the operator moves manual release  164  to its unrelease position, automatic lock  162  functions normally, locking belt  132  after its subsequent extension stops and retraction begins, just as before. In one embodiment of the invention, manual release  164  is spring loaded, overriding automatic lock  162  for only so long as the operator holds manual release  164  in its release position, and manual release  164  automatically returns to its unrelease position when the operator stops holding it. In another embodiment of the invention, manual release  164  does not automatically return to its unrelease position, but stays in its release position until manual moved back to the unrelease position. In yet another embodiment, no manual release is provided and automatic lock  162  is only released when belt  132  is withdrawn substantially completely into retractor assembly  138 . This arrangement is familiar to passengers in automobiles who use seat belts.  
         [0049]     In the preferred embodiment, however, manual release  164  is preferably biased toward its unrelease position, so that the operator has to hold the manual release in the release position once the automatic lock engages if he wishes to further extend belt  132 .  
         [0050]     Belt  132  is preferably a fabric strap. Alternatively, belt  132  may be a cable, cord or chain.  
         [0051]     Coupling  134  is preferably a steel hook. It may be covered with rubber or plastic for better gripping. Alternatively, coupling  134  may be a D-ring, a C-ring, a chain link, an eye, or a fabric loop formed in the end of belt  132 .  
         [0052]     Cover  142  encloses retractor assembly  138  and protects it and belt  132  from the elements. Cover  142  includes a hinge  174  and a hinge spring  176 . Cover  142  is generally box-shaped, having five walls and one open side. The open side faces mounting plate  136  and retractor assembly  138 . Hinge  174  is attached to mounting plate  136 , and is pivotally connected to cover  142 . Hinge spring  176  is configured to bias cover  142  toward mounting plate  136 .  
         [0053]      FIG. 5  demonstrates a method of securing the work vehicle to trailer  104  for transport. The work vehicle is first driven onto trailer  104 . The operator then extends belts  132  from the four tie downs  124 ,  126  and attaches the belts to fixtures  110 . The operator then tensions the belts. Once the belts are tensioned appropriately, the operator then drives a cargo vehicle  100  to the next job site.  
         [0054]     In step  178 , the operator drives vehicle  106  up ramps  108 , onto trailer  104  of cargo vehicle  100 , to an appropriate central position on trailer  104 .  
         [0055]     Vehicle  106  is preferably positioned such that at least two front fixtures  110  are disposed forward of the vehicle and forward of tie downs  124  to permit belts  132  from tie downs  124  to be extended downward, forward, and away from the vehicle by the operator to the at least two fixtures  110  to which tie downs  124  are coupled.  
         [0056]     Similarly, vehicle  106  is preferably positioned such that at least two rear fixtures  110  are disposed behind the vehicle and behind tie downs  126  to permit belts  132  from tie downs  126  to be extended downward, backward and away from the vehicle by the operator to the at least two fixtures  110  to which tie downs  126  are coupled.  
         [0057]     Vehicle  106  is also preferably positioned such that at least two left side fixtures  110  are disposed on the left side of the vehicle such that left side tie downs  124 ,  126  can be extended by the operator downward, outward, to the left, and away from vehicle  106  to left side fixtures  110 .  
         [0058]     Vehicle  106  is further preferably positioned such that at least two right side fixtures  110  are disposed on the right side of the vehicle such that right side tie downs  124 ,  126  can be extended by the operator downward, outward, to the right, and away from vehicle  106  to right side fixtures  110 .  
         [0059]     In step  180 , the operator climbs out of the operator compartment of tractor  102 , or out of the operator compartment  130  of vehicle  106  after having driven vehicle  106  onto trailer  104 . The operator grasps the free end of a first tie down  124 ,  126 , and pulls that tie down toward the appropriate cargo-securing fixture  110 . Reel  156  of that tie down unwinds under spring tension provided by spring  172  until coupling  134  of the tie down reaches the desired fixture  110  on trailer  104 . The operator then attaches coupling  134  to desired fixture  110  and releases belt  132 . Spring  172  then retracts any slack in belt  132 , winding it around reel  156 . Automatic lock  162  engages, preventing belt  132  from being further withdrawn from retractor assembly  138 .  
         [0060]     Should the operator wish to reposition this tie down, after it has been tensioned, he presses manual release  164 , withdraws additional slack from retractor assembly  138 , and unhooks coupling  134  from the desired fixture  110 .  
         [0061]     Alternatively, if the operator is satisfied with the location of the first tie down, he repeats the belt-extending and coupling-attaching steps of the two previous paragraphs for the remaining three tie downs.  
         [0062]     The tie downs may be initially locked with manual lock  160  in their retracted positions when the operator drives vehicle  106  onto trailer  104 . If they are locked, the operator first switches manual lock  160  to its unlock position, releasing belts  132 , before withdrawing belt  132  from retractor assembly  138  and connecting coupling  134  to fixture  110 .  
         [0063]     If the operator wants additional security, he can alternatively engage manual lock  160  of the tie downs after they have been coupled to fixtures  110 .  
         [0064]     In step  182 , the operator tensions the belts of the tie downs in any manner, for example (1) by releasing them and having them rewind automatically into retractor assembly  138 , (2) by manually tightening them, (3) by raising the loader arms, or (4) by driving the vehicle forward or backward to apply a tension to the belts.  
         [0065]     Steps  180  and  182  can be intermixed. The operator need not attach all the tie downs to the trailer, and subsequently tension all the tie downs.  
         [0066]     For example, in one method the operator can attach tie downs  126  to fixtures  110  located behind vehicle  106 , then release the tie downs for automatic rewind into retractor assembly  138 , or alternatively drive vehicle  106  forward, thereby taking the slack out of belts  132  extending from tie downs  126 .  
         [0067]     Alternatively, the operator could attach tie downs  124  to fixtures  110  located forward of vehicle  106 , then release the tie downs for automatic rewind into retractor assembly  138 , or alternatively drive vehicle one of six backward, thereby taking the slack out of belts  132  extending from tie downs  124 , or alternatively raise loader arms  118  tensioning both of tie downs  124  simultaneously.  
         [0068]     Once rear tie downs  126  are attached to their respective fixtures  110  and tensioned, the operator can subsequently attach front tie downs  124  and tension them. Similarly, once front tie downs  124  are attached to their respective fixtures  110  and tensioned, the operator can subsequently attach rear tie downs  126  and tension them.  
         [0069]     As yet another alternative, the operator can successively attach and tension each tie down  124 ,  126  individually, such as by retracting (and thereby tensioning) each tie down in turn as soon as it is coupled to its fixture  110 .  
         [0070]     The particular order and combination of steps will depend on the type of work vehicle  106 , the type of cargo vehicle  100 , the location and type of fixtures  110  on trailer  104 , and the locations of tie downs  124 ,  126  on work vehicle  106 , as well as operator preference and skill level.  
         [0071]      FIG. 1  illustrates work vehicle  106  oriented in the same direction as cargo vehicle  100 , with the front of both vehicles facing to the left. In an alternative process of attaching work vehicle  106  to trailer  104 , vehicle  106  can be backed up ramps  108  such that vehicle  106  faces in the opposite direction as cargo vehicle  100 .  
         [0072]     If the work vehicle  106  is loaded on to trailer  104  of cargo vehicle  100  backwards, with its front end facing the rear of the cargo vehicle and its rear end facing the front of the cargo vehicle, the preferred tie down attachment points would be reversed. Belts  132  from tie downs  126  would preferably extend forward (with respect to cargo vehicle  100 ) to fixtures  110 , and belts  132  from tie downs  124  would extend backward (with respect to cargo vehicle  100 ) to fixtures  110 .  
         [0073]     It will be understood that changes in the details, materials, steps, and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the invention. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown.  
         [0074]     For example, there are alternative methods, structures, and configurations to the preferred embodiments such as using a chain, cable, or cord for a belt, rather than a reinforced flat fiber strap. The method of tightening the tie down may include an intermediate winch or manual tensioning device located partway along the belt or at either end. As a further example, the tie downs may be permanently fixed to the work vehicle, such as by welding or riveting. Further, the retractor assembly may be mounted directly to the work vehicle, rather than being fixed to the intermediate mounting plate  136  that, in turn, is fixed to the work vehicle.  
         [0075]     Cargo securing fixtures  110  can be a slot, as shown herein, but may also include a pin, ring, rail, aperture, or hook.  
         [0076]     Retracting device  158  can use a different actuator in place of spring  172 , such as a hand crank, a winch, or an electric motor. A spring-loaded automatic retracting device is, however, the preferred embodiment due to its simplicity and ease of use.  
         [0077]     Manual lock  160  is shown herein as a pushbutton lock. In an alternative configuration, other structures may be used to activate the lock, such as levers, toggles, knobs, or solenoids.  
         [0078]     Cargo vehicle  100  may be configured as two or more units pivotally coupled together such as the tractor and trailer illustrated herein. For example, instead of towing a single trailer  104 , tractor  102  can be coupled to (and tow) two or more trailers  104 . Alternatively, cargo vehicle  100  can be a single unitary structure, such as a flatbed truck, enclosed truck, or car carrier.  
         [0079]     Tractor  102  can be a common tractor for a tractor-trailer rig, as shown here. Alternatively, it may be an automobile, pickup truck, dump truck, or other vehicle configured for towing a trailer.  
         [0080]     Trailer  104  is preferably the dual axle trailer  104  shown herein, but may alternatively be a flatbed trailer, enclosed trailer, or single or multilevel “car carrier” trailer, for example.  
         [0081]     Tie downs  124 ,  126  may be fixed to other portions of work vehicle  106 , however. For work vehicles  106  other than skid steer loaders, the tie downs may be mounted to the frame, chassis, blade, bucket, excavator, backhoe, or other strong rigid component of the work vehicle.  
         [0082]     Smaller work vehicles  106  may only require two tie downs to adequately secure them to trailer  104 . Larger (or longer) work vehicles may require six or more tie downs to adequately secure them to trailer  104 .