Abstract:
Configurations and installation methods for vehicle tire chains which provide tire chains especially easy to mount, and provide improvements in performance and vendor supply.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This is a continuation (CIP) of application Ser. No. 11/030,682, filed Jan. 5, 2005. 
   FEDERALLY SPONSORED RESEARCH 
   Not applicable. 
   SEQUENCE LISTING OR PROGRAM 
   Not applicable. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to vehicle tire chains, specifically configurations and mounting methods that allow chains, as described, to be mounted onto a wheel more easily than previously possible. 
   2. Prior Art 
   Tire chains are available in many configurations, including the following: Chains are available made of steel link chain or made of multi-strand steel cable. The most common configuration of link type chains is the so called ladder type, consisting of two side members and a multiplicity of cross members arrayed on the tire tread and attached to the two side members. Other, more complex configurations made of link chain include a so called diamond pattern. Cable chain configurations include the ladder type and a so called diagonal or zig zag type pattern. 
   The diamond pattern is disclosed in U.S. Pat. No. 3,842,881, Oct. 22, 1974, Muller et al, and the zig zag pattern in U.S. Pat. No. 5,056,574 Oct. 15, 1991, Maresh, et al, and several earlier patents, including U.S. Pat. No. 1,486,993, Mar. 18, 1924, Stolpe. Both of these patterns utilize a distinctive mode of installation on the wheel, involving arraying the chain on the ground in front of the wheel, sweeping it to the rear of the wheel and drawing chain elements forward for fastening, including drawing lower chain portions around the tire to ground contact area. While this mode is claimed to be “easy mounting”, the step of sweeping the chain to the rear of the wheel can be quite inconvenient in soft snow or mud. 
   The ladder pattern and other patterns typically use the drive-over method of chain installation. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention discloses improvements in a category of vehicle tire chains which utilizes the mounting step of imposing cross chains on the tire to ground contact area. These improvements include configurations for easier mounting, improved stabilization of the chain against operating forces, and an improved method of vending the chain. 
   OBJECTS OF THE INVENTION 
   An object of this invention is to provide a vehicle tire chain which is easier to install on a wheel than the prior art. 
   A further objective is to provide an easy to mount tire chain, which can be fully mounted during one stop of the vehicle. 
   A further object is to provide an easy to mount tire chain which can be mounted during one stop of the vehicle and will be self actuating to provide adequate traction elements uniformly over the tire tread, specifically to fill in the tire to ground contact area, not covered upon initial mounting. 
   A further object is to provide an easy to mount tire chain which can be mounted during one stop of the vehicle and which will be fully serviceable in resisting and tolerating random operating forces significantly greater than normal, such as those from heavy braking, turning and skidding. 
   It is an additional objective to use the principles of this invention to enable a specific, given chain, to fit a broader range of tire sizes, to improve the marketing economics, as to manufacturing cost, inventory and parts supply. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic plan view of a zig zag pattern tire chain. 
       FIG. 2  is a schematic partial plan view of the tire chain of  FIG. 1 . 
       FIG. 3  is a schematic elevation of the chain of  FIGS. 1 and 2 , using a known art tightener configuration. 
       FIG. 4  is a schematic elevation of a zig zag pattern chain using a six hook elastic tightener loop and a non elastic stabilizing connector. 
       FIG. 5  is a schematic elevation of a zig zag pattern chain using an elastic tightener band on the lower segment of the side chain and a non elastic loop hooked to other segments. 
       FIG. 6  is a cross member extension device for link chains. 
       FIG. 7  is a cross member extension device for cable chains. 
       FIG. 8  is a cross member extension device fitted with a non return feature. 
       FIG. 9  is a schematic plan of a ladder chain fitted with two cross chain extensions. 
       FIG. 10  is a schematic plan of a ladder chain with two deflected cross chains oriented diagonally. 
       FIG. 11  is a schematic elevation of a chain with two deflected cross members fitted with extension device. 
       FIG. 12  is a schematic elevation of a chain with one deflected cross member fitted with extension device. 
       FIG. 13  is a view of equivalent tire sizes for tire chain supply. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The present invention can only be adequately understood by noting the operating characteristics of the known art which the present invention is applied to. 
   A commercially popular model of tire chain is based generally on Maresh, et al, U.S. Pat. No. 5,056,574, and is shown in  FIGS. 1 ,  2 , and  3 . The Maresh chain utilizes a diagonal pattern, or so called zig zag pattern of cross chains. Six repetitions of the pattern are generally sufficient for a passenger car tire chain. Six repetitions leaves room for significant slack in the side chains, between attachment points of paired cross chains. The chain is stabilized by a loop of elastic band  55 , hooked into each side chain segment, using hooks  59  in  FIG. 3 . 
   This elastic loop serves to provide both a required tensioning function and a required chain stabilizing function. The tensioning function is required because the mounting procedure involves imposing an adjacent pair of cross chains upon the contact area between the tire and the ground or roadway. This deflects the two cross chains  51  and  52  in  FIGS. 1 ,  2 , and  3 , causing the cross chain ends to retract from the side chain connections, thus depressing the side chains. 
   The cross chains must be pulled into their normal operating positions, when the wheel is turned, releasing the tire to ground contact pressure. The tension required to move the chains is quite small, on the order of a pound, but it is an important function. 
   The inner face side chain is inaccessible, so the tension must be applied to the outer face side chain. 
   The other function, that of stabilizing the chain against operating forces, is much more demanding, in terms of force levels, as the primary chain elements, cross chains and side chains, must withstand normal operating forces due to driving, turning, braking, and also higher level forces such as severe braking and skidding. 
   The elastic loop  55  in  FIG. 3  performs the tensioning function quite well, but random operating forces can exceed the capability of the elastic loop to withstand. The present invention involves replacing the elastic loop with a combination of elastic connectors and steel, or non elastic connectors, arranged to fulfill the two necessary functions, tensioning and stabilizing. 
   The stabilizing function can be greatly improved by the use of steel or non elastic connectors, in conjunction with the elastic tightener. There is a myriad of possible patterns for such steel connectors. A minimum configuration would be a single strand of chain, oriented horizontally (during mounting) and hooked to the side chain segments on each side of the lateral attachment points. ( 61  in  FIG. 4 ). 
   Some stabilization will extend to the other four attachment points, above and below. The six hook elastic band  62 , used for tensioning, will add further stabilizing to the upper and lower attachment points. 
   The release of the deflected cross chains upon vehicle movement allows the bottom segments of both the outer face side chain and inner face side chain to rise. The rear face action can be passed up the rear face and over the top resulting in a dropping of the outer face side chain top segment. In  FIG. 5 , elastic band  71  is hooked to the lower segment of the outer face side chain and to the upper segment connections, and a non elastic connector is hooked to the other segments. 
   In the chain of  FIG. 5 , tension is applied to the outer face top and bottom segments, to ensure proper repositioning of the deflected cross chains. An elastic tightener band will suffice. 
   As a matter of technique, the steel connector, or connectors, would be hooked onto the side chain, before the side chain is hooked to itself to form a loop on the wheel. That attachment will tighten the side chain into the multiplicity of hooks on the steel connector. 
   After the side chain is connected, the tightener band is applied, which will further integrate the assembly. The tension at each hook need not be excessive, as there is no elasticity in the steel connectors. 
   A no slack side chain is greatly distinguished from the above described high slack chain, in that the no slack chain is self stabilizing when fully mounted. 
   The present invention includes a somewhat more advanced solution to the situation described above with the high slack chain. The innovation is to provide a sliding connection of the deflected cross chains, such as  51  and  52  in  FIGS. 1 ,  2 , and  3 , to the outer face side chain  22 . The purpose is to allow the deflected cross chains to retract through the sliding connections, when imposed upon the tire to ground contact area. This allows the outer face side chain to be fully connected (to itself) during the initial mounting procedure, without regard to the position of the deflected cross chains. 
     FIG. 6 , for link chain, and  7 , for cable chain, show the cross chain extension and sliding connection to the outer face side chain  22 . Tension devices  82 , typically elastic tightener bands, are attached to the extended ends of the cross chains, to pull the deflected cross chains  81  into position, upon initial operation of the vehicle. 
   To prevent random operating forces from pulling the deflected cross chains back through the sliding connections, a non return device can be built into the sliding connection. There is a myriad of ways such a device could be configured. It can be as simple as a notch  85  on the side of a flat bar, as in  FIG. 8 , which engages a stop bar  86  on the side chain, to prevent return movement. This device must be rugged and sturdy to withstand unusually high random operating forces, for instance a skid onto bare pavement. 
     FIG. 9  shows the cross chain extensions  91  and  92  applied to adjacent cross chains  93  and  94  in a ladder pattern tire chain. It is advantageous to orient the cross chains diagonally, as  95  and  96  in  FIG. 10 , to shorten the distance between fully connected adjacent cross chains  97  and  98 , and to improve the support for the sliding connections. 
     FIG. 11  shows two deflected cross chains fitted with extensions  99  and  100  and tensioned by elastic bands  101  and  102 .  FIG. 12  shows a single cross chain extension. 
   In the commercial marketing of tire chains, it is highly desirable that a given tire chain fit the largest possible range of fire sizes, in order to minimize the required inventory to stock chains for sale for all tire sizes. The principles of the present invention can be utilized to help meet this objective. The following discussion relates only to fire chains which have relatively long segments of the outer face side chain, such as the zig zag and diamond patterns. Excluded from this discussion would be the ladder and similar patterns. The discussion does relate to both cable and link type construction. 
   The chain to suit a certain tire size will have the appropriate diameter of both inner and outer face side chains, as well as the appropriate length of cross members. That chain can be used, as is, for all equivalent tire sizes, in which a decrease in tire diameter is matched by an increase in width, or an increase in tire diameter is matched by a decrease in width, as shown in  FIG. 11 , so the side chains stay at the same diameter. The limit of this variation is the preferred minimum distance from each side member to the outer tire diameter. 
   That chain, as selected, can not be used for a larger tire size (larger than the equivalent tire sizes) as the side chain diameters are set; that is, increasing the diameter of a side chain or the length of cross chains makes it a different chain, by definition. 
   The selected chain can readily be used for a smaller tire size by arranging to take care of the slack in the outer face side chain segments, between the cross chain attachment points, created by moving the cross chain attachment points on the outer face to a smaller effective diameter of the side chain, as defined by the cross chain attachment points. 
   Examples of the elastic tensioning devices and non elastic stabilizing devices which make up the connector sets to put with the basic chain, are shown in  FIGS. 4 and 5 . 
   Since it is impractical to change the inner face side chain diameter, it is preferable to start with the minimum practical inner face side chain diameter, leaving the greatest room to reduce tire diameter, without going below the desired minimum clearance of inner face side chain diameter and tire diameter. This discussion assumes that all size variations are taken into account at the outer face side chain. 
   The novel features of the present invention are entirely usable for tire chains for dual wheels. 
   All of the chains claimed in this application can be adapted to a mounting method of “sweeping about the bottom of the tire”, as described in Maresh, et al, or the “over the top” mounting method described in inventor&#39;s earlier application, as both employ the step of imposing cross chains onto the tire to ground contact area, which these disclosures are based on. Only the “over the top” method can be used on dual wheels, whether the chain be single or dual, as the second wheel interferes with the “sweep about the wheel”. 
   It will be evident to those skilled in the art that many variations can be made in the configurations, which are not herein described in detail. Such variations should be considered to be within the scope of the invention if within the encompass of the appended claims.