Abstract:
A vehicle traction enhancement system for use in a vehicle storage compartment such as a trunk or truck bed, to add weight or ballast above the driven wheels to improve traction, especially during times of inclement weather. The system includes an elongated carrier and retention devices or compartments for the weights.

Description:
TECHNICAL FIELD 
       [0001]    This invention relates generally to vehicle traction enhancing devices, particularly of the ballast weight type for a rear wheel drive vehicle. 
       BACKGROUND 
       [0002]    Ground vehicles, such as an automobile or a truck, are dependent upon good traction between their tires and the road upon which they are being driven. Traction is a function of the coefficient of friction between the tire and the road on which it travels, and the force (weight) pushing the tire into contact with the road. Maintaining high traction is desirable for control of the vehicle. Traction is maximized when the coefficient of friction and vehicle weight are both high. 
         [0003]    Under normal driving conditions, a high coefficient of friction, readily available from the good tire and road materials that are commonly used, leads to satisfactory traction for any given vehicle weight. Since traction is normally satisfactory, vehicle designers try to minimize vehicle weight to achieve several benefits, including improved fuel economy. Throughout the history of automotive travel, vehicles have had to contend with weather conditions such as rain, snow, and ice that reduce the coefficient of friction between the tires and the road, thus making vehicle traction temporarily less than satisfactory. At these times, the often-employed method for enhancing traction is to temporarily increase the weight acting downward on the tires, by making the vehicle heavier. This increased weight is most desirable over the “driven wheels” that have the tires that must transmit the torque of the engine to the road surface. 
         [0004]    In many automobiles, such as pickup trucks and rear wheel drive sedans, a storage compartment such as a trunk or a cargo bed sits near the driven wheels. Empty storage compartments such as these are among the lightest areas of the vehicle, so tires located near them have little weight forcing them into contact with the road. However, these compartments do provide an area to which weight, sometimes referred to as ballast, can be temporarily added. Some examples of readily available weights that have been temporarily added include snow, tree stumps, boulders, containers filled with sand or water, and large concrete blocks. These materials, and others, are often placed loosely in the storage compartments. 
         [0005]    Drawbacks of these various materials can include difficulty in carrying them to and from the vehicle, storing them when not installed, securing them to prevent movement, and a low weight to volume ratio that causes the storage compartment to be too full to perform its primary function of carrying the goods for which it was intended. 
         [0006]    Thus, a need exists for an easy to use high-density, aesthetically pleasing, modular vehicle traction enhancement system that can be installed and removed by people of limited lifting ability. The system should be optimized to consume a minimal amount of the available cargo space. 
       SUMMARY 
       [0007]    One embodiment of a vehicle traction enhancement system according to this invention includes an elongate carrier selectively coupled to a bed of a vehicle storage compartment. The system includes a plurality of retention devices spaced along a length of the carrier, and a plurality of weights each selectively retained by one of the retention devices on the carrier. The carrier and associated weights are positioned relative to the driven wheels of the vehicle to increase traction of the vehicle. 
         [0008]    Other embodiments of this invention are directed to the system in combination with the vehicle and a method of enhancing vehicle traction. 
         [0009]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the principles of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0010]      FIG. 1  is a perspective view of an exemplary vehicle traction enhancement system installed in the bed of a rear wheel drive truck. 
           [0011]      FIG. 2  is a view of part of the embodiment of  FIG. 1 , showing an open compartment receiving a weight, and the attachment between the truck bed and the belt. 
           [0012]      FIG. 3  is a perspective view of the embodiment of  FIG. 1  installed in an automotive sedan&#39;s trunk. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]      FIG. 1  depicts a vehicle traction enhancement system  10  in a bed  12  of a storage compartment  14  over the driven wheels  16  of a vehicle  18 . 
         [0014]      FIG. 2  depicts the traction enhancement system  10  that includes an elongate carrier  20  having compartments  22  that act as a retention device for weights  24 . Weights  24  can be provided as a part of the system, or alternatively assimilated from readily available materials such as barbell weights or construction materials. Weights  24  are preferably of a size that is convenient for even a person of small stature and strength to individually carry and install, yet not so small that it would take an unreasonably large number of compartments and weights to achieve a significant weight gain. A weight of approximately 12 lbs would be an example of a preferred size for the individual weights, but larger or smaller compartments and weights could also be used. Each compartment  22  has a flap  26  acting as a closure mechanism. The flap  26  and the compartment  22  include mating hooks and loops fasteners such as Velcro™ portions  28   a  and  28   b,  although alternatively, other fastening systems well known in the art could be used. 
         [0015]    To fasten the system  10  to the bed  12 , a variety of methods could be used. In this embodiment, mating Velcro™ portions  30   a  and  30   b  are shown at one end of the carrier  20 , and identical pieces are used on the other end (not shown). Carrier  20  has Velcro™  30   a  attached to it by stitching or other methods, and bed  12  has Velcro™  30   b  attached by an adhesive or another attaching process. Carrier  20  along with the Velcro™ portions  30   a  may be installed and removed as needed by mating the portions  30   a  and  30   b  together, either when the carrier is loaded with weights  24 , or preferably when it is empty so that the person need not lift and work with such a heavy object. Other examples of fastening devices instead of Velcro™ could be nuts and bolts or hooks and eyes. 
         [0016]    Optionally, an anti-skid material (not shown), such as textured rubber, could be used under the bottom of the carrier  20  to reduce the loads transmitted to the fastening device  30   a  and  30   b  while the vehicle changes speed or direction. 
         [0017]      FIG. 3  is another embodiment of system  10 , very similar to that installed in  FIG. 2 . In this embodiment the flaps  26  covering the opening  25  (not shown) of the compartments  22  are facing the opening  32  of storage compartment  14 , which is in the rear of the vehicle  18 . This rearward orientation of opening  25  is preferred so that a person standing at the opening  32  of the trunk and installing weights  24  into the compartments  22  extends their reach less than if the openings  25  were facing forward. This is ergonomically beneficial to the person loading and removing the weights. Carrier  20  has a Velcro™ hook portion  34   a  under its entire length. If the carpet  36  in the trunk is of a loop-like nature that will mate to the hook portion  34   a,  then the other portion of Velcro™ is not needed. Otherwise, a loop portion  34   b  (not shown) is used atop the carpet and under hook portion  34   a.    
         [0018]    While this invention has been illustrated by the description of one or more embodiments thereof, and while the embodiments have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. For example, the compartments  22  that are depicted in the preceding drawings include sides that are approximately perpendicular to their tops and bottoms. Other embodiments could have the compartment formed from only a top and a bottom material, with appropriate slackness to allow a weight to fit inside. Also, while each of the preceding drawings showed only one carrier  20  installed, the modular nature of the device includes the ability to install these side by side, anywhere they will fit in the storage compartment  14 . The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the general inventive concept.