Abstract:
A tie down strap is used for securing cargo or to attach various objects. A tie down strap is made from a bicycle tire inner tube and clips which can be removeably and adjustably attached to either end of the bicycle tire inner tube which is cut along a radial axis.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This patent application is a continuation of U.S. patent application Ser. No. 13/316,947, filed Dec. 12, 2011, entitled METHOD FOR USING A BICYCLE TIRE INNER TUBE TO MAKE A TIE DOWN STRAP, which claims the benefit of U.S. Provisional Patent Application No. 61/459,401, filed Dec. 13, 2010, entitled METHOD FOR USING A BICYCLE INNER TUBE TO MAKE A TIE DOWN STRAP. 
     
    
     FIELD 
       [0002]    The present invention relates generally to a method and apparatus for making an adjustable tie down strap. 
       BACKGROUND 
       [0003]    Generally elastomeric cords used to tie down cargo or attach various objects are comprised of so-called bungee cords which include a length of pre-fabricated elastic cord with a hook made from a bent metal rod permanently secured to both ends. The metal hooks create the danger of scratching painted or finished surfaces as well as the danger of injuring a person&#39;s eye if they come loose and snap back. In addition, bungee cords are not long enough so stretch around an automobile from front to back or even from side to side, so they cannot be used to strap cargo to a car or truck. A long bungee cord would be expensive because of the cost of a long pre-fabricated elastomeric cord. Bungee cords are not easily attached to themselves to form a loop, because they do not lock together in a manner which prevents disengagement when the bias from the elastomeric cord is released. Finally the length of a typical bungee cord is not adjustable because the hooks are permanently fixed to the ends of the elastomeric cord. Therefore there is a need for an elastomeric strap which is adjustable in length, can be used over long distances, such as between front and rear bumpers of a car, and has ends which do not present dangers of scratching finished surfaces or injuring eyes. 
       SUMMARY 
       [0004]    The present invention solves the problems in prior art elastomeric straps by providing a pair of clips which can be removeably and adjustably attached to a bicycle tire inner tube and which also can be locked to each other. Bicycle tire inner tubes are relatively long and can be stretched to about three times their relaxed length. They also have no cost and are readily available, because they are generally discarded when they develop an air leak and cause a flat tire on a bicycle. The clips which are attached to the bicycle tire inner tubes in the present invention are preferably made of plastic so they will not scratch a surface to which they are attached, and their ends are rounded so they do not present the danger of injuring a person&#39;s eye if they break or come loose. Each clip has one end portion comprised of a planar surface which includes a pair of slots formed therethrough for securing the bicycle tire inner tube so that the bicycle tire inner tube can be slid through the slots to create a functioning strap of an adjustable length. Each clip also has a second end portion comprised of an engaging means for engaging surfaces such as a grommet, an edge of an automobile body, a metal rod, a right angle such as a corner of a garage or other building, or another clip. The second end portion may comprise a hook or J shape which is substantially in the same plane as the first end portion. Alternatively, the second end portion may comprise an area which has been bent into a U-shape or S-shape which allows two clips to be locked together so that a single strap of the present invention can have its two ends locked together to form a loop, and so multiple straps of the present invention can be attached in sequence to create one very long elastomeric strap. The U-shape or S-shape embodiments may include a lug that can be used to engage a structure such as a grommet in a tarpaulin and which fits into a corresponding opening on another clip when two clips are locked together. A method is described for manufacturing clips of the U-shape or S-shape embodiments 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a partial perspective view of a first device constructed in accordance with the present invention. 
           [0006]      FIG. 2  is a side elevation view of the  FIG. 1  device hooked together with another substantially identical device. 
           [0007]      FIG. 3  is an enlarged sectional view of a portion of the devices shown in  FIG. 2 . 
           [0008]      FIG. 4  is a cross-sectional end view of the bed of a pickup truck in which two devices of the present invention are hooked together as shown in  FIG. 2  to secure a load of cargo in the bed of the truck. 
           [0009]      FIG. 5  is a partial perspective view of a second device constructed in accordance with the present invention. 
           [0010]      FIG. 5A  is a partial perspective view of a device similar to  FIG. 5  except including a lug and lug receiving slot. 
           [0011]      FIG. 6  is a side elevation view of the  FIG. 5  device hooked together with another substantially identical device. 
           [0012]      FIG. 6A  is a side elevation view of the  FIG. 5A  device hooked together with another substantially identical  FIG. 5A  device. 
           [0013]      FIG. 7  is a partial perspective view of a third device constructed in accordance with the present invention. 
           [0014]      FIG. 8  is a side elevation view of the  FIG. 7  device hooked together with another substantially identical device. 
           [0015]      FIG. 9  is a partial perspective view of a fourth device constructed in accordance with the present invention. 
           [0016]      FIG. 10  is a side view of the current invention to use it to attach a tarpaulin to the side of a pickup truck in which three devices of the present invention are used. 
           [0017]      FIG. 11  is a side elevation view of a sheet of plastic which has been cut for manufacturing clips. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Indicated generally at  10  in  FIG. 1  is a device constructed in accordance with the present invention. The device includes a commercially available bicycle tire inner tube  12  that has been cut along a radial axis to create a first end  14  and a second end  15  (in  FIG. 4 ). Device  10  also includes a first clip  16  and a second clip  17  (in  FIG. 4 ) that are substantially identical to one another. Clip  16  includes a pair of parallel slots  18 ,  20  (shown partially in dashed-line configuration) formed therethrough. Slots  18  and  20  are formed adjacent a first end  22  of the clip. The end  14  of bicycle tire inner tube  12  is frictionally engaged with clip  16  by threading it through slots  18  and  20  as shown. 
         [0019]    Although the inner tube engaging openings in the illustrated embodiment are slots, many other types of openings could serve the purpose of frictionally engaging the bicycle tire inner tube well enough to prevent slipping in response to tensile forces while also allowing the user to adjust the effective length of the resulting elastomeric strap by sliding the bicycle tire inner tube through the openings. For example, tapered slots could allow for very quick adjustment. Similarly, either one or both of the slots might have one open end to facilitate inserting and adjusting the bicycle tire inner tube. Although the slots in the illustrated embodiments are shown parallel, it is to be understood that the slots do not have to be parallel to one another. Although the illustrated embodiments are made of plastic other materials might be employed as well. 
         [0020]    A U-shaped cross section is shown adjacent a second end  24  of the clip, as shown more clearly in  FIG. 3 . A lug  26  extends from end  24  of the clip and a rectangular opening  28  is formed through a second clip  30 , in  FIGS. 2 and 3 . The dimensions of opening  28  are slightly wider and higher than lug  26 , as viewed from end  24 . This permits engagement of a pair of clips, such as clip  16  and clip  30 —which is substantially identical to clip  16 —as shown in  FIGS. 2 and 3 . The lugs on each of the clips, like lug  26  on clip  16 , are also well suited for hooking through a round opening, for example, a grommet on a tarpaulin. In  FIG. 2  a bicycle tire inner tube  32  is engaged with slots, such as slots  18  and  20  in clip  16 , in the same manner as the bicycle tire inner tube is connected to the other clips. 
         [0021]    In  FIG. 4 , boxes such as  36  and  38  comprise a load in a pickup truck bed  34 . Clips  16  and  30  are hooked together near the middle of the load as depicted in  FIGS. 2 and 3  to create a device which includes two bicycle tire inner tubes linked in series. The other end of inner tube  32  includes another clip  40 , secured thereto in the same fashion as each of the other clips. Each of clips  17  and  40  are hooked over a downward-projecting metal potion  42 , 44 , correspondingly, on opposite sides of the truck bed. The clips are well suited for hooking onto the edges of metal, like the sheet metal edges found on the edges of car bodies, the rain gutters found on the edges of car roofs, or car bumpers. 
         [0022]    In  FIGS. 5 and 6 , a second device  46  is also constructed in accordance with the present invention. 
         [0023]    Device  46  includes a clip  48  having an S-shaped portion  50 . In  FIG. 6 , a second clip  52 , which is substantially identical to clip  48 , also includes an S-shaped portion  54 . S-shaped portions  54  and  50  have a resiliency due to the sharp curve by which the S-shaped portions are connected with the planar surfaces containing parallel slots such as  18 ,  20  shown in  FIGS. 1 and 5 . Because of that resiliency, when engaged as shown in  FIG. 6 , boundaries  56  and  58  between the corresponding S-shaped portions snap the convex portions of the S-shaped portions which engage them and thereby lock together, engaging the clips with one another. An opening  60 , defined between boundaries  56  and  58 , provides an area in which a screwdriver or the like may be inserted and twisted to force clips  48  and  52  apart when it is desired to unlock them. The clips shown in  FIGS. 5 and 6  can be connected to bicycle tire inner tubes as illustrated in  FIGS. 1 and 2  and also attached to a truck body in the same fashion as shown in  FIG. 4 . When clipped over metal portions on the pickup truck bed, like portions  42  and  44 , the clip of  FIG. 5  is hooked over the metal portion until the outermost end of the metal portion is received within space  62  of clip  48 . 
         [0024]    Although the clips in this second illustrated embodiment do not contain lugs and the corresponding openings as in the first described embodiment, it is to be understood that the lugs and openings in which the lugs fit could be included in the second embodiment with S-shaped clips as well as in the first embodiment with U-shaped clips. 
         [0025]      FIGS. 5A and 6A  illustrate the embodiments of  FIGS. 5 and 6  with clips that have respective lugs  47  that are positioned within respective lug receiving openings  51  when the clips are hooked together as shown in  FIG. 6A . Like the embodiment of  FIG. 1 , the lug  47  is shown projecting from the edge  49  of the clip in a direction toward the tube portion  12 . 
         [0026]    In  FIGS. 7 and 8 , a third embodiment  64  is constructed in accordance with the present invention. Device  64  includes a clip  66  having a J-shaped portion  68  that is substantially in the plane of the clip  66 . In  FIG. 8 , a second clip  70 , which is substantially identical to clip  66 , also includes a J-shaped portion  72 . The J-shaped portions  72  and  68  are small enough to engage a grommet on a tarpaulin and are also shaped to engage a framework such as a rod, shaft, or sheet metal edge. The clips shown in  FIGS. 7 and 8  can be connected to the bicycle tire inner tubes as shown in  FIGS. 1 and 2  and attached to a truck body in the same fashion as shown in  FIG. 4 . When clipped over metal portions on the pickup truck bed, like portions  42  and  44 , the clip of  FIG. 7  is hooked over the metal portion until the outermost end of the metal portion is received within space  80  of clip  66 . 
         [0027]    In  FIG. 9 , a fourth clip embodiment  82  is also constructed in accordance with the present invention. Clip  82  includes a pair of modified parallel slots  84 ,  86  formed therethrough. Slots  84  and  86  are formed adjacent a first end  88  of the clip. These slots are open on one end to facilitate engaging the bicycle tire inner tube by threading it through slots  84  and  86 . The J-shaped end portion  90  extends from end  92  of the clip and connects with a similar opening in a second clip. 
         [0028]    In  FIG. 10 , three identical clips of this fourth embodiment are used with a single bicycle tire inner tube to secure a tarpaulin  35  over a load such as a load in a pick-up truck bed  34 . The J-shaped end portions of the clips which are attached to the ends of the bicycle tire inner tube  32  are attached to projections  33  of the pick-up truck bed  34 . The J-shaped end portion of the clip which is located in the middle portion of the bicycle tire inner tube  32  engages a grommet in the tarpaulin  35  and thereby hold it down. 
         [0029]    The clips of these embodiments may be manufactured by cutting and then bending sheets of plastic such as ¼ inch thick nylon. Plastics which are relatively heat resistant are preferred so that the clips do not soften too much in heat and direct sunlight.  FIG. 11  shows one of those sheets after having been cut out leaving rows of panels, which will later be bent and cut out to form the finished clips. The clips in the sheet are tabbed together at areas such as  94 ,  96 ,  98 ,  100 , and  102  to facilitate handling of the sheets. In the next stage of manufacturing, the sheets are bent with a hinging action of one mold portion (the swinging portion) against a fixed second mold. Because of the shape of the clip, a hinging mold is particularly easy to remove from the product after it cools. The swinging first mold and/or the fixed second mold may contain sharpened areas to cut the tabs between adjacent parts while bending the parts. 
         [0030]    Having illustrated and described the principles of our invention in a preferred embodiment thereof, it should be readily apparent to those skilled in the art that the invention can be modified in arrangement and detail without departing from such principles.