Abstract:
A traction device for vehicle tires is provided for when the vehicle is stuck in mud, snow, ice or similar terrain, comprising an adjustable support member having a first end and a second end; a connection member extending from the first end of the support member, wherein the connection member is connectable to a wheel; a shaft extending from said second end of said support member; and a traction member rotatably mounted to the shaft, wherein the traction member includes one or more tire-gripping portions. A double-ended embodiment of the traction device is also disclosed for providing greater traction in appropriate situations.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     I. Field of the Invention  
         [0002]     The present invention relates generally to devices used to impart traction to vehicle tires for extraction of the vehicle from mud, snow, ice, sand or similar terrain, and more particularly to such devices which are portable and quickly attachable and detachable from the wheel.  
         [0003]     II. Background and Prior Art  
         [0004]     Since the invention of the automobile, drivers have invariably found themselves stuck in mud, snow, ice or sand. With little or no traction between the tire and the surrounding medium, it can be exceptionally difficult to move it from its stationary position using only the engine power of the stuck vehicle. Over the years, a range of techniques have been used in an attempt to overcome the situation. To this day, for example, coarse mats or wooden boards are often placed under the tire to provide some additional traction. The problem with this technique is that the traction is only provided instantaneously, and the mats or boards are forcibly expelled from contact with the tire upon rotation of the tire.  
         [0005]     Consequently, there have been various types of traction devices and means for attachment to a tire which are known in the prior art. Many such prior art devices are quite inconvenient or nearly impossible to attach to the vehicle wheel or tire when the vehicle has become mired in mud, snow, ice, sand or the like. Conventional winter tire chains are a well known example. Frequently the vehicle operator gets soiled while attaching the device, particularly if the vehicle must be raised by a jack in order to install the traction device. Furthermore, rain, snow or other dampness usually reduces the coefficient of friction between prior art traction devices and the tire, permitting the traction device to slip circumferentially about the tire during use. Other devices have been conceived such as short segments of chains or bars which extend across the tire tread. However, most of these devices are rather cumbersome to use and require a fastening arrangement or specific tools to hold the device onto the tire.  
         [0006]     Along with all of the above short-comings, it must be borne in mind that persons unfamiliar with specialized tools or emergency procedures may find themselves alone in such situations. Therefore, it is imperative that an effective tire traction device be attachable and removable quickly and easily, without the need to jack the vehicle, and without having to use tools which are often unavailable. The traction device should also be relatively small and portable, preferably adjustable for a range of wheel and tire sizes, and capable of imparting substantial traction when deployed. Based on the ensuing description and claims, it is believed that the present invention satisfies all of these requirements and provides a viable solution that is novel in comparison to the prior art.  
       SUMMARY OF THE INVENTION  
       [0007]     Therefore, one object of the present invention is to provide a tool-free tire traction device which is easily and quickly attached to and detached from a vehicle wheel and tire.  
         [0008]     It is also an object of the present invention to provide a tool-free tire traction device which is small and portable.  
         [0009]     A further object of the present invention is to provide a tool-free tire traction device which provides substantially greater traction when deployed.  
         [0010]     Another object of the present invention is to provide a tool-free tire traction device which is adjustable for a range of wheel and tire sizes. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  depicts a preferred embodiment of a tool-free tire traction device in accordance with the present invention.  
         [0012]      FIG. 2  depicts an alternative embodiment of the invention featuring an adjustable support member.  
         [0013]      FIG. 3  depicts an alternative embodiment which illustrates a spring-biased adjustability feature for the support member.  
         [0014]      FIG. 4  depicts is an elevation view of a typical vehicle wheel having a plurality of mounting holes with a traction device installed in an operative position.  
         [0015]      FIGS. 5 and 6  are alternative cross-sectional shapes for a traction member which engages the tire.  
         [0016]      FIG. 7  depicts a double-ended embodiment of the invention which mounts across two of the mounting holes in the wheel.  
         [0017]      FIG. 8  is another embodiment of a traction device mounting system employing re-designed lugs and an adaptor socket which permit use of the invention with any standard wheel. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0018]     Turning now to  FIG. 1 , a preferred embodiment of a tool-free tire traction device in accordance with the present invention is shown. The traction device  1  generally comprises a support member  2  having a first end  3  and a second end  4 ; a connection member  5  extending from the first end  3  of the support member  2 ; a shaft  16  extending from the second end  4  of the support member  2 ; and a traction member  6  rotatably mounted to the shaft  16 . Preferably, the traction member  6  further includes one or more tire-gripping devices  7 .  
         [0019]     With specific reference to the connection member  5 ,  FIG. 2  depicts one alternative embodiment wherein the connection member  5  is a separate part attached by a common fastener to the first end  2  of the support member  2 . The connection member  5  is adapted to matably engage a portion of the wheel  8 . For example, the connection member  5  may be a simple pin  12  adapted for matable insertion into a specially formed mounting hole  9  on the wheel  8 . A predetermined plurality and pattern of such mounting holes  9  are preferably provided on the wheel  8  during its manufacture, such that the traction device  1  may be placed in any one of a multiple of locations.  FIG. 4  illustrates a typical vehicle wheel comprising a hub  30 , a wheel  8 , mounting lugs  31 , and the tire  32 . Traction device mounting holes  9  are shown in at least four places, with a traction device  1  installed in an operative position. For example, when a vehicle is stuck in mud or snow, the lower half of the wheel  8  may be embedded up to the axle, thus obscuring one or more mounting holes  9 . However, the remaining visible mounting holes  9  will be available for mounting of the traction device  1 . Optionally, as shown in the detail view of  FIG. 3 , in order to prevent the traction device  1  from inadvertently detaching from the wheel  8 , a locking device  10  may be included on the connection member  5  that may engage a portion of the wheel  8 . One form of such a locking device  10  would be a spring-loaded ball bearing located along the pin  12 , which engage a circumferential groove on the inside of the mounting hole  9 .  
         [0020]     With respect to the support member  2 , it is desirable that it be adjustable in length. Specifically, referring to  FIGS. 2 and 3 , the support member  2  may include a primary member  13  and a secondary member  14 , wherein the primary member  13  and the secondary member  14  are coaxially and telescopingly connected to one another. When configured in this manner, a locking device  15  should be present and configured to lock the position of the primary member  13  relative to the secondary member  14 . While the locking device  15  may comprise a variety of forms, a preferred method would include a spring-loaded pin on the inside telescoping member which is engageable with any one of a multiple of locking holes formed into the outside telescoping member. Alternatively, both primary and secondary members  13 ,  14  may include a plurality of holes which can be matched for the appropriate length, and then locked by a separate locking pin inserted across both primary and secondary members  13 ,  14 . Optionally, the primary member  13  may further be resiliently biased toward the secondary member  14  by an internal spring  23  within the telescoping arrangement as best shown in  FIG. 3 . In such a configuration, the spring  23  may be used to bias the telescoping members to a normally shortened length, such that extension of the telescoping members against the resilient bias of the spring  23  would allow extension of the support member  2 . One end of the spring  23  would be held in place relative to the primary member  13  by a cross-pin  24 , while the opposite end of the spring  23  would be attached to secondary member  14 . To prevent separation of primary and secondary members  13 ,  14 , secondary member includes a pin  25  which travels within a guide slot  26  formed into primary member  13 . At least one advantage of this configuration is that once the traction device  1  is installed, the spring would additionally serve to hold the traction device  1  in placed prior to powering the wheel  8 . When installed, the support member  2  should be substantially parallel with a radius of the wheel  8 .  
         [0021]     Yet another means of adjusting the length of the support member  2  would be achieved by having the primary member  13  and the secondary member  14  coaxially and threadably connected to one another. In that configuration, the primary member  13  may be turned relative to the secondary member  14  until the desired length is achieved prior to installation of the traction device  1  on the wheel  8 .  
         [0022]     The traction member  6  is the key element of the present invention, as it makes the contact with the mud, snow, or terrain in which the vehicle may be immobilized. As indicated above, the traction member  6  is rotatably mounted onto the shaft  16 , and retained by conventional bolts or nuts at opposite ends of the shaft  16 . Optionally, a retaining clip  45  may also be installed onto shaft  16 , which extends toward the tire  32  to assist in preventing any substantial lateral movement of the device  1  during operation. The retaining clip  45  may simply comprise a metal plate having a slot, such that it can freely move with respect to the shaft  16 . During use, the retaining clip  45  will be urged inward by the force of the terrain, but it should be easily movable for removal of the device  1  from the tire  32 .  
         [0023]     Traction member  6  may comprise a wide range of cross-sectional shapes designed to make the best traction with the terrain. For example,  FIGS. 5 and 6  show at least two possible alternative cross-sectional shapes, with the understanding that there can be many variations having substantially the same function. Regardless of the cross-sectional shape, however, the traction member  6  will include at least one traction blade  17  extending longitudinally along the traction member  6 . The traction blade  17  will typically be approximately the same length as the width of the tire  32 , because such length would provide the greatest traction. In one embodiment shown in  FIG. 5 , the traction blade  17  is shown roughly in the form of triangle, such that there are opposing concave surfaces  18 ,  19  which contact the terrain. In addition to the traction blade  17 , the traction member  6  also preferably includes a plurality of tread-engaging cleats  20  placed longitudinally along the length of traction member  6 . Cleats  20  serve to anchor the traction member  6  against the treads of the tire  32  when installed to minimize lateral and circumferential movement of the device  1  as the wheel  8  is being turned.  
         [0024]     An alternative embodiment of the invention is also shown in  FIG. 7 , which is a double-ended traction device  21 . Construction of the alternative embodiment device  21  is similar in most respects. However, the device  21  includes a crossbar  22  which is mounted onto two or more mounting holes  9 , such that a traction member  6  is located along two locations on the tire  32 . In the adjustable version shown, the two secondary members  14  may be extended as required or configured with the spring system as described with respect to  FIG. 3 . By virtue of its design, this embodiment affords potentially double the traction in comparison to the first embodiment.  
         [0025]     Finally, as shown in  FIG. 8 , an alternative means of mounting the traction device  1  is illustrated in detail. In this embodiment, when the wheel  8  is mounted in the normal manner to the hub  30 , one or more of the standard mounting lugs  31  are replaced by re-designed lugs  40 , which have additional external threads  41 . When the need to use the traction device  1  arises, an adaptor socket  42  having internal threads is matably engaged to the new lug  40  simply by hand tightening. The socket  42  includes a cylindrically shaped internal opening which can receive the connection member  5  as described earlier herein. Such connection can be secured by the same type of locking device  10  as well, namely spring-loaded balls located on the connection member  5  which engage a circumferential groove on the inside of the socket  42 . In this novel arrangement, no special modifications to the wheel  8  are required, and any standard wheel  8  can be used with the traction device  1  merely by attaching the adaptor socket  42  over the new lugs  40 .  
         [0026]     It should be noted that the present invention can easily be used in connection with snow chains to augment the traction required for a particular situation. For example, while conventional snow chains generally comprise a continuous network of links which surround the entire circumference of a tire, shorter lengths of snow chains may be employed which cover a smaller portion of the circumference. Specifically, a short section of snow chain, i.e. one that covers only 25% to 40% of the circumference, can be attached to at least two instances of the present invention when the devices  1  are mounted to a wheel. In this arrangement, the traction member  6  is removed from each of the devices  1 , thereby exposing the shaft  16 . Links on the snow chains may then be slid over the shaft  16  on one of the devices  1 , while the links on the opposite end of the snow chain are attached similarly to a second device  1 . Finally, the bolt or other hardware is reinstalled at the end of shaft  16 , perhaps with a large washer, in order to prevent inadvertent slippage of the snow chains off of the device  1 .  
         [0027]     Although exemplary embodiments of the present invention have been shown and described, many changes, modifications, and substitutions may be made by one having ordinary skill in the art without necessarily departing from the spirit and scope of the invention.