Abstract:
A tire chain for adding traction to a vehicle tire riding on snow and/or ice. The tire chain includes side members encircling the sides of the tires and cross members that extend across the tread from side member to side member. Securement devices secure the cross members to the side members. The securement devices include a hook shape defining an enclosure and an opening to the enclosure and a biasing member that spans the opening. The securement device is secured to one of the members and is snap locked onto the other member to enable manual removal of a selected one of the cross members for replacement.

Description:
FIELD OF THE INVENTION 
     This invention relates to a tire chain for enhancing gripping of a tire in conditions of snow and ice and more particularly to the replacement of worn or broken cross members. 
     BACKGROUND OF THE INVENTION 
     Tire chains as contemplated herein are intended for mounting to driven wheels of a vehicle when a roadway is covered with snow or ice. Mounting to non-driven wheels in addition to driven wheels is optional for maximum control in severe conditions. Additionally, the use of traction devices such as tire chains is required by law when driving on snow and ice covered roads in several states, notably California, Oregon and Washington. Tire chains are not intended for dry road surfaces and the chain&#39;s cross members (which wrap across the tire tread between two side members) will rapidly wear when driven on dry road surfaces. Thus, the chains are to be demounted from the tire as a vehicle enters and exits ice and snow laden road conditions. 
     A vehicle needs to be driven at a reduced speed when driving on traction devices/tire chains. A chain component that breaks or comes loose can cause damage to the vehicle being driven at a high speed. Even at slow speeds a broken cross member requires that the vehicle be stopped and the tire chain repaired or replaced. The present invention is directed to a releasable securement device for releasably securing cross members to a tire chain side member as when replacing a broken cross member and particularly when cross member replacement is required by the vehicle&#39;s driver while on the road and between destinations. 
     BRIEF DESCRIPTION OF THE INVENTION 
     It is to be understood that the terms traction chains, traction devices or tire chains refer to that product which includes a pair of circular side members designed to extend around the opposed side walls of a tire, the side members connected together by cross members that wrap across the tire tread from side member to side member. (See FIG. 1) The side members may be loops of cable, a steel hoop, plastic, composite material or loops of interconnected links. The cross members may be lengths of cable or lengths of interconnected links or plastic or composite material and the side members and cross members of a given chain may be any combination, i.e., cable cross members and cable side members, cable cross members and link side members, link cross members and cable side members or link cross members and link side members, composite cross members and link side members, cable cross members and steel hoop side members, etc. 
     The problem of cross member replacement has existed since tire chains were first adopted for enhanced tire traction on ice and snow. The problem has existed particularly for truck drivers having to traverse mountain regions when hauling loads cross country. The sheer weight and power of a large truck both accelerates the wearing of tire chains and the likelihood of cross member breakage when weakened by wearing. It is accordingly not uncommon for truck drivers to have to pull over along snow/ice laden roadways and replace a broken cross member. Not replacing or repairing the chain is not an option as the loose cross member is then whipped around the side of the tire and can wrap around or impact various objects in the vicinity of the wheel and cause immeasurable damage and safety hazards. 
     Heretofore replacement of cross members typically required the removal or at least the loosening of the tire chain and then the wielding of a large pliar-like tool to force open a metal clamp securement device. A replacement cross member would then have to be secured to the side member again by the wielding of the pliar-like tool to squeeze shut the open clamp. Alternatively, and particularly when the pliar-like tool was not available to a driver, the cross member was repaired in a very temporary manner using a wire wrap or repair link to secure the cross member to the side member. Such was intended only for a temporary fix to enable the driver to limp cautiously to the closest point of shop repair hoping other cross members wouldn&#39;t break along the way. 
     The preferred embodiment of the present invention provides a secure, finger actuated snap lock-type releasable securement device permanently affixed to each end of a cross member. The cross member as initially assembled to the side member is snap locked to the side members by the securement devices. When replacement is required, the driver merely presses a spring of each securement device to allow disassembly by hand and a replacement cross member is snap locked to the side member in its place. The design of the invention also allows for actuation with common hand tools if desired. 
     In one embodiment, the clamp is a metal plate that is formed into a hook shape at one end and crimped at the other end onto the cross member. A metal spring (e.g., leaf spring) is anchored to said other end and extends to a position at the opening of the hook shape. A side cable or side link is pressed against the metal spring bending it out of the way as the cable or side link is forced into the hook. The metal spring snaps back to close off the opening and prevents removal of the side member except by intentional deflection of the metal spring. 
    
    
     Other variations include elastomer springs that accomplish a similar function as the metal spring. Several embodiments are disclosed in the detailed description which follows having reference to the accompanying drawings. 
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates a vehicle wheel including a tire having one type of tire chain or traction device (a “ladder” style) incorporating a releasable securement device in accordance with the present invention; 
     FIG. 2 is a cross sectional view as taken on view lines  2 — 2  of FIG. 1; 
     FIG. 3 is a top view of a cross member of the tire chain of FIG.  1  and FIGS. 3A and 3B illustrate the formation of a securement for the cross member; 
     FIG. 4 is a side view of the cross member of FIG. 3 as indicated by view lines  4 — 4  in FIG. 
     FIG. 5 is a perspective view, FIG. 6 is a side view and FIG. 7 is an end view showing assembly of a snap lock configuration of a link-type cross member connected to a link-type side member in accordance with a second embodiment of the invention. 
     FIGS. 8,  9 ,  10  and  11  illustrate a snap lock configuration of a still further embodiment of the invention; 
     FIGS. 12A,  12 B,  13 A, and  14 A illustrate a snap lock configuration of a still further embodiment of the invention; 
     FIGS. 15A and 15B illustrate a still further embodiment; 
     FIGS. 16A and 16B illustrate a still further embodiment; 
     FIGS. 17-20 illustrate a still further embodiment of the invention; and 
     FIGS. 21-25 illustrate modifications to the embodiment of FIGS.  17 - 20 . 
    
    
     DETAILED DESCRIPTION 
     Reference is made to FIGS. 1 and 2 which illustrate a vehicle wheel  20  having a tire chain  22  (alternatively “traction device”) mounted on the wheel. Shown in the FIG. 1 embodiment is a link-type side member  24  and cable-type cross member  26 . FIG. 2 is a side view of a single cross member  26  that more clearly illustrates the manner of securing the cross member  26  to the side members  24  using a securement device  28  in accordance with the first embodiment of the invention. 
     It will be appreciated, and as well known to users of such traction devices, the tire chain when mounted to a tire and mounted on a vehicle and driven on ice or snow is subjected to varying forces that induce wear and breakage of the device and particularly the cross members. On an icy road the tread portion  30  of the wheel  20  tends to slip whereas the cross members  26  dig into the ice and resist slippage. The side members  24  are tightly held against the tire and thus the connection between the side members and cross members have to withstand the opposing forces acting against the cross members and the side members of the traction device. The configuration of the securement device  28  must be such as to withstand these opposing forces. However, these forces are primarily pulling forces and sometimes twisting forces as applied to the securement device  28 . Minimal or no force is acting to push the side member and cable portions together, i.e., to collapse or compress the securement device. 
     Reference is now made to FIGS. 3 and 4 which are enlarged and more detailed views of the cross members  26  and securement device  28  but including a partial view of side members  24 . As mounted on a tire, the view of FIG. 3 is an outside view, i.e., the side of the securement device exposed for viewing when mounted on the tire and will sometimes be referred to as the top view of the cross member. This is the side that contacts the road as the cross member is rolled under the tire. FIG. 4 is a side view of the cross member. These views show the cross member laid straight for illustration purposes but of course they take a U-shape when mounted on a tire as seen in FIG.  2 . 
     The cross member  26  as previously indicated is a cable-type cross member and other than the portion thereof referred to as the securement device  28 , is a construction well known to the industry and will not be further explained. The securement device  28  of this first embodiment is primarily constructed from a flat steel plate as illustrated in FIGS. 3A and 3B. The inner end  32  is folded around its longitudinal axis and crimped onto the cable end (solid line to dash line) and the outer end  34  is folded along a lateral axis into a hook shape (also solid line to dash lines). 
     Returning to FIGS. 3 and 4, attached to the formed plate is a metal spring  36  (see FIG.  4 ). One end of the spring  36  is a roll form  38  and is secured in a notch  40  provided in the formed plate. The metal spring  36  is permanently biased to a position across the hook opening as shown in solid lines and can be depressed inwardly as illustrated in dash lines at the top end shown in FIG.  4 . As will be noted, a link  44  of the side member  24  also shown in dash lines at the top end in FIG. 4 seats far enough into the hook shape to permit the metal spring  36  to snap back into its closed position (and also to be depressed back down to its dash position for disconnect as will be is explained). A thumb notch  42  (FIG. 3) is provided in the outer hook shape end  34  to aid in depression of the metal spring  36 . 
     It will be appreciated that the cable-type cross member  26  can be readily secured to a link-type side member  24  by simply positioning a link  44  of the side member  24  against the metal (e.g., leaf spring  36  (illustrated at the bottom end of the cross member in FIG.  4 ), applying pressure to depress spring  36  (see arrow) and then sliding the links  44  into the hook portion  34  until the spring  36  is released, at which point the spring snaps back into the closed position as shown (referred to as a snap lock). Release of the securement device from the side member  24  is achieved manually. The vehicle operator presses his thumb (or an available tool, e.g., screwdriver, pliar) against the distal end of the spring  36  as enabled by notch  42  to flatten the spring against the bottom of the hook shape (dash line position at the top end of FIG. 4) and thereby permitting sliding of the link  44  from the hook shape of the connector or securement device  28 . 
     Reference is now made to FIGS. 5-7 showing a further embodiment of the invention. FIGS. 5-7 illustrate a securement device  46  that is designed to secure a link-type cross member  26 ′ to a link-type side member  24 . As shown in FIGS. 5 and 6, a claw-type link connector  48  is similar to the connectors which are currently in use. However, with the current versions, the hook portions  50  are simply squeezed together, e.g., using a specialized pliar-type tool, to lock the link of the side members to the connector. In the present invention, a spring clip  52  is biased across the opening of the link as shown. Again the spring  52  is pressed down by the link  44  of the side member  24  for permitting entry of link  44  into the hook-shaped end as indicated by the arrow in FIG.  7 . The spring  52  snaps back across the opening for interlocking the side and cross members as illustrated in FIGS. 5 and 6. The device is disconnected, again by an operator pressing his thumb across the bar boss  54  of the spring to enable the hook portion  50  to be released from the side member  24 . 
     FIGS. 8-11 illustrate a further embodiment applicable to a link-type cross member connected to a link-type side member. FIG. 8 is an elastomeric spring  58  and FIG. 9 illustrates an alternative claw-type link connector  60 . The spring  58  is configured at one end with notches  62 . At an intermediate position, the elastomer spring is configured with a cut out  64  forming a tongue  66  and having a locator/reinforcement boss  67 . At the opposite end, the spring is provided with an opening  68  including a stabilizing tip  69 . As shown in FIG. 9, the spring is secured to the loop  56  of the connector  60  via the notches  62  at said one end and the opening  68  allows the opposite end to be forced over end  70  of the connector. (See also FIG. 10 which shows spring pad  58  as it appears both before and after assembly to link  44  of side member  24 .) Link  44  is forced against the elastomer spring as seen in FIG. 11 (and note arrow) to compress the spring  58  as seen in FIG. 11 to position the link  44  inside the hook portion of connector  60  as seen in FIGS. 9 and 10. The tongue  66  with locator/reinforcement bars  67  juts up against the link  44  and resists disconnection as noted in FIG.  10 . Again the operator places a thumb against the spring  58  to compress the spring and permit removal of the link  44 . 
     FIGS. 12A,  12 B,  13 A and  14 A illustrate use of a further elastomer-type spring to replace the metal spring of the embodiments of FIGS. 1-4. The spring  36 ′ is shaped to form a C-shape at the distal end  74  to provide the desired biasing force to close off the opening to the hook end. As noted in the progression of FIGS. 12A,  13 A and  14 A, the link  44  of the link-type side member  24  is pressed against the distal end to collapse the end  74  of the spring (see arrow in FIG. 12A) and then slides under the hook end  34  (arrow in FIG. 13A) to snap lock the connector  32  and thus the cross member to the side member. 
     FIGS. 15A and 15B illustrate an embodiment whereby the securement device (connector)  28  of FIGS. 1-4 is applied to a cable-type side member  24 ′. As noted, this side member  24 ′ is provided with bushings  76  that are crimped in place on the cable. The cable has a cross section mated to the hook-shaped end  34  of connector  28  (See FIG. 15B) and readily permits manipulation of metal spring  36 . 
     FIGS. 16A and 16B illustrate a further variation of FIGS. 15A and 15B. A metal plate  78  is clamped onto the cable-type side member. An eyelet  80  is provided in plate  78  for connection by the connector  28  of cross member  26 . 
     FIGS. 17-20 illustrate a still further embodiment of the invention. In FIGS. 17-20, the connector portion  82  (FIG. 17) is a swivel-type connector that is secured to the side member  88  rather than the cross member as particularly noted in FIG. 17. A swivel shank  84  fits through the opening of a link  86  of a link-type side member  88 . A washer  90  is fitted over the hook end  92  of the shank  84 , then elastomer pad  94  and a pivot plate  96 . The hook end  92  is provided with finger openings  98  that receive fingers  100  of plate  96 . The hook end  92  receives the end link  102  of a link-type cross member  104 . As illustrated in FIG. 19, the pivot plate  96  is pressed down to provide an opening to the hook end and the end link is inserted as shown. Removal is provided by pressing the link  102  against the plate  96  to compress the elastomer pad  94  and permit disconnect of the side member. An advantage of this embodiment is that the shank  84  will swivel as indicated by the arrows  106  in FIG.  18 . Thus, the cross member  104  can rotate or roll relative to the side member to relieve the twisting force otherwise applied to the connector (securement device). The rotation of the cross member allows the chain to wear on all sides increasing the effective life of the chain. 
     FIGS. 21 and 22 illustrate a connector similar to that of FIGS. 17-20 but having a coil spring  94 ′ replacing elastomer pad  94 . 
     FIGS. 23-25 illustrate a connector also similar to that of FIGS. 17-20 but replacing the pivot plate  96  with a floating gate-type washer  96 ′. 
     The above are but several of the embodiments that fall within the scope of the invention herein and will prompt others skilled in the art to conceive of numerous variations and modifications. For example, several combinations of springs are shown with each embodiment, but not all possible combinations. It should be appreciated that all the types of springs shown could be used with all the embodiments within the scope of the invention. The invention is accordingly intended to be encompassed by the terms of the claims herein that broadly interpret in the common every day use thereof within the industry.