Patent Publication Number: US-2022227188-A1

Title: Anti-skid device with external mounting to the hub of a wheel particularly for wheels with alloy rims

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to an anti-skid device, commonly referred to as a snow chain, for wheels with alloy rims, designed to be mounted from the side of the wheel turned towards the outside of the vehicle. 
     Description of the Related Art 
     Snow chains are known with external mounting that comprise a central hub from which a plurality of arms or spokes protrude radially, connected to a terminal element that embraces the tread of the tire. The terminal elements of the spokes are connected to chain segments that follow the tire tread. In this way, the chain segments can scratch or score the sleet or ice on the road surface to exert greater friction and prevent the tires from slipping and skidding. 
     For the attachment and tensioning of this type of snow chains, the most common solution is to provide an adapter element that is attached to a wheel bolt or nut. The adapter element is attached to the end of a tensioning belt or chain which traverses the hub of the anti-skid device, where means of various type are provided, such as lever, ratchet, or the like, which can be actuated by the user to tension the belt and bring the hub of the anti-skid device closer to the hub of the wheel. 
     Such a type of snow chain has various disadvantages due to the way in which the tensioning element is fixed to a bolt of the wheel. 
     In fact, users must normally use a special wrench to screw-fix the adapter device to the bolt. In some cases a lever is provided, fixed to the adapter, to enable the screwing thereof, a lever which remains on the wheel during travel, so that a force acting in the direction opposite to that of screwing on the adapter device would tend to loosen the clamping of the same. 
     In addition, the fixing of the tensioning element to a bolt of the wheel is somewhat difficult and not entirely reliable. 
     Moreover, since the bolts for fixing of the wheel are distanced from the centre of the same, and consequently the element of connection to the hub of the anti-skid device is offset with respect to the wheel, this may result in imperfect tensioning and/or mounting of the anti-skid device. 
     Snow chains of the type described above are known, for example, from WO 03/011618, EP 2050590 and EP 528506. 
     U.S. Pat. No. 2,517,634 and EP 35282874 describe other anti-skid devices with external mounting with features. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to eliminate, or at least reduce, the disadvantages of the prior art illustrated above. 
     In particular, one object of the invention is to provide an anti-skid device for wheels with alloy rims, i.e. provided with a hole at the hub, closed by a small disk normally bearing the car manufacturer&#39;s logo, which is easy and quick to assemble and disassemble. 
     Another object of the invention is to provide such an anti-skid device wherein the tensioning element is perfectly in axis with the wheel, in such a way as to allow a symmetrical and uniform distribution of the tensioning forces and ensure safety and reliability during travel of the vehicle. 
     These and other objects are achieved by the anti-skid device as disclosed and claimed, as are various advantageous embodiments. 
     Substantially, the anti-skid device with mounting from the outside for wheels, particularly with alloy rims with a central hole, according to the invention, comprises:
         a central body intended to be placed at the hub of a wheel on which the anti-skid device is to be mounted,   a plurality of arms projecting radially from said central body and terminating in terminal elements intended to be placed on the tire tread,   chain segments connected to said terminal elements so as to form a ring on the tire tread,   a device designed to be attached to said rim of the wheel;   a connecting element between said fixing device and said central body of the anti-skid device, and   a tensioning mechanism placed in said central body which can be operated to pull said connecting element and bring the central body closer to the hub of the wheel, wherein said fixing device is an expansion fixing device which is fixed in said central hole of the rim of the wheel.       

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features of the invention will be made clearer by the detailed description that follows, referred to its embodiments purely by way of a non-limiting example, illustrated in the accompanying drawings, in which: 
         FIG. 1  is a schematic view in perspective, illustrating the mounting of an anti-skid device fitted with a device for fixing to the rim of the wheel according to a first embodiment of the invention; 
         FIG. 2  is an enlargement showing in particular the connection between the anti-skid device and the fixing device mounted on the wheel before tensioning; 
         FIG. 3  shows schematically a wheel with the device for fixing of the anti-skid device according to the previous figures mounted thereon; 
         FIGS. 4 and 5  are schematic perspective views of the fixing device in rest and working condition respectively; 
         FIGS. 6 and 7  are axial schematic sections of the fixing device of  FIGS. 4 and 5 , respectively, placed in the hole of the hub of a wheel; 
         FIGS. 8 and 9  are perspective views of a second embodiment of the fixing device, in rest and working condition respectively; 
         FIGS. 10 and 11  are schematic sectioned views of the device of  FIGS. 8 and 9 , respectively, mounted on the wheel; 
         FIGS. 12 and 13  are schematic views in perspective of a fixing device according to a third embodiment of the invention, in rest and working condition respectively; 
         FIGS. 14 and 15  are views in median section of the device of  FIGS. 12 and 13 , respectively, mounted on a wheel. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , an anti-skid device according to a first embodiment of the invention, denoted as a whole by reference numeral  1 , is shown during the phase of mounting on a wheel  100 . 
     The anti-skid device, or snow chain,  1 , comprises a hub or central body  2  intended to be placed at the hub of the wheel. From the central body  2  of the anti-skid device arms or spokes  20  branch off radially. Four arms  20 , each consisting of a pair of appropriately shaped metal rods, are shown in the drawings. 
     The ends of the arms  20  are connected to respective terminal elements  21  bent with a radius of curvature that follows the edge of the tire, in such a way that the terminal elements  21  can be placed on the tread of the tire of the wheel. Chain segments  3  are connected to the terminal elements  21  and are arranged in a ring along the tread of the tire. By way of example, the drawing shows two chain segments  3  arranged substantially parallel one to the other. At appropriate intervals, the chain segments  3  are connected one to the other and held in position by transverse plates  30  which are arranged in a knife pattern on the tread of the tire, in such a way as to improve friction with the road surface, cutting into the ice or snow. 
     Between at least some pairs of transverse plates  30  an adjustment device  4  is placed, in itself known, to adapt the chain segments  3  to slightly different wheel diameters or even to compensate the wear of the tire, which leads to a reduction in wheel diameter. For the mounting of the anti-skid device  1  to wheel  100  a device is provided for fixing to the central hole  101  of rim  102  of wheel  100 . 
     This device, which will be described in greater detail here below, is denoted by reference numeral  50  in  FIGS. 1 to 7 , and is connected by means of a belt  10  to a mechanism  11  placed in the central body  2 , and through actuation thereof it is possible to tension the anti-skid device. 
     This mechanism  11  is in itself known and, only by way of example, in  FIG. 1  it is shown as a ratchet lever, as described for example in European patent EP 2050591, to which reference can be made for further details of the same. 
     It should also be noted that the connection between the central body  2  of the anti-skid device and the fixing device  50  can be made, instead of with a belt as shown in  FIG. 10 , with a chain, a steel cable, or the like. 
     Likewise, this belt  10  can be permanently connected to the fixing device  50 , or hooked thereto during mounting, in which case it will be removable. 
     Before describing in detail the device for fixing to the wheel, which is a specific subject of the invention, the mounting of the anti-skid device is described in brief. 
     Referring to  FIG. 1 , the user grasps two spokes  20  of the anti-skid device  1  to mount them on the outer part of wheel  100 , placing the ring formed by the chain segments  3  on the tread of the tire. 
     As shown in  FIG. 2 , the operator then grasps the fixing device  50  and locks it in the central hole  101  of the wheel. 
     Naturally, if device  50  is separated from belt  10  or other element of connection to the central body  2  of the anti-skid device, it will be placed in hole  101  beforehand, and then belt  10  will be hooked thereto. 
     At this point, the tensioning mechanism  11  is actuated by means of the ratchet lever  12 , causing the belt  10  to be shortened, and therefore the central body  2  of the anti-skid device  1  to be brought closer to the hub of the wheel, tensioning in this way the terminal elements  21  of the arms  20  on the tire. 
     For dismounting, the procedure is in reverse order, releasing the ratchet tensioning mechanism, so as to cause the belt  10  to loosen, allowing the anti-skid device  1  to move away from the wheel and its removal, following the release of the belt  10  and/or the removal of the fixing device  50 . 
     Referring to  FIGS. 3 to 7 , fixing device  50  is described according to a first embodiment of the invention. 
     In  FIG. 3 , fixing device  50  is shown mounted in the central hole  101  of an alloy rim  102  of a wheel  100 . 
     In fact, alloy rims are provided with a blind hole  101  at the hub normally covered by a small disk usually bearing the logo of the car manufacturer of the vehicle, following the removal of which device  50  can be mounted in said hole  101 . 
       FIGS. 4 to 7  show in greater detail the structure of fixing device  50  and its mounting in hole  101 . 
     Device  50  comprises a pair of disks  51 ,  52  parallel to and coaxial one with the other, the lower disk  51  (referring to the drawings) being made integral with the end of a rod  53 , at least partially threaded, which traverses a threaded hole  54  provided centrally to the upper disk  52 . 
     The end of the rod  53  can be connected in a fixed manner to the lower disk  51 , so that these two elements behave as a monobloc, or connected in such a way that the disk  51  is free to rotate around the rod  53 . 
     Between the two disks  51  and  52  L-shaped tabs  55  are placed (three in number in the example shown), with the ends bent at 90° outwards. 
     The upper bent ends  56  are housed in corresponding holes  57  formed in the upper disk  52 , while the lower bent ends  58  are engaged with the inner wall  103  of the hole  101  during mounting. 
     At the other end of the rod  53 , opposite that of engagement with disk  51 , a polygonal head  60  is provided to allow the screwing/unscrewing of the rod  53 . On the head  60  a small pin  61  is provided, which can be optionally pivotally mounted with respect to the head  60 , carrying an eyelet  62  for the insertion of the belt  10 . 
     Naturally the shape of the head  60  and of the small pin  61  with eyelet  62  is purely indicative, as these elements can take on other forms suitable for the purposes, i.e. the rotation of the rod  53  and the engagement of the connecting element  10  with the central body  2  of the anti-skid device. 
     A pressure spring  63  that acts between head  60  and upper disk  52  can also be provided on rod  53 . 
       FIG. 4  shows device  50  in a non-operational condition, with tabs  55  in “loosened” condition. 
     In this condition, device  50  is positioned against the hub of the wheel, inserting the tabs  55  in the hole  101 , as shown in  FIG. 6 . 
     In this condition, by rotating the threaded rod  53  in the direction of screwing in the threaded hole  54  of the upper disk  52 , since this disk is prevented from rotating, a backward movement of the lower disk  51  is produced, and therefore its moving closer to the upper disk  52 , with consequent expansion of the tabs  55 , as shown in  FIG. 5 , which go to engage with the inner surface  103  of the hole  101  producing the locking of device  50  in the hole  101  following tight tightening. 
     A possible unhooking of device  50  from hole  101  is prevented, as well as by the strong engagement of the bent ends  58  of the tabs  55  with the inner surface  103  of hole  101 , by an inner perimeter protrusion  104 , normally provided for the hooking of the cover disk (removed), against which the bent ends  58  of the tabs  55  would abut. In  FIGS. 4 and 6  the bent ends  58  of tabs  55  are shown at a certain distance from the perimeter protrusion  104 , but in practice they are closer to protrusion  104 , or in any case they can be made in such a way as to be closer to protrusion  104  or even to abut against it. 
     The spring  63  can contribute to avoiding any unscrewing of the rod  53  after mounting. Referring to  FIGS. 8 to 11 , a description is now given of a second embodiment of the fixing device, denoted by reference numeral  50 ′, using the same reference numerals of the previous embodiment to distinguish identical or similar parts. 
     The device  50 ′ again comprises two parallel and coaxial disks  51 ,  52 , with a rod  53  attached to the lower disk  51  and traversing a smooth hole  54  provided centrally to the upper disk  52 . 
     Around the rod  53 , which in this case is shown to have a larger diameter with respect to the rod  53  of the previous embodiment, a toroidal expandable elastic element  55  is arranged. 
     At the section of the rod  53  protruding beyond the upper disk  52  a lever  70  is hinged, having, at the hinge axis  71 , a pair of cam profiles  72  in contact with the upper disk  52 . The cam profiles  72  are such that rotating lever  70  from the position shown in  FIGS. 8 and 10  to the position shown in  FIGS. 9 and 11  causes the lower disk  51  to move closer to the upper disk  52  and therefore the expansion of the elastic element  55 , which goes to abut against the inner wall  103  of the hole  101 , producing the locking of the fixing device  50 ′ in the hole  101 . 
     In this embodiment, at the top of the rod  53  a small pin  61  is shown again with eyelet  62  for the attachment of the belt  10 , or generic connecting element, to the central body  2  of the anti-skid device  1 . 
       FIGS. 12 to 15  show a third embodiment of the fixing device denoted by reference numeral  50 ″. 
     This device comprises a hollow cylinder  80 , open below and having a widened upper base  81 , having a central threaded hole  82  in which a rod  83 , at least partially threaded, carrying a conical body  84  below, is engaged. 
     In the side wall  85  of the hollow cylinder  80  holes  86  are provided (four in number in the accompanying drawings, arranged at 90° one in relation to the other), in which blocks  87  are housed, held together by a toroidal rubber ring  88 , which traverses them. The blocks  87  have an internal bevel  89  with an inclination corresponding to that of the conical body  84 . 
     In the accompanying drawings a similar bevel is also provided on the outer side of blocks  87 , in such a way that they are perfectly symmetrical, and their mounting can be simplified. 
     At the upper end of the rod  83  a polygonal head  60  is provided with small pin  61  and eyelet  62  (not shown in the drawings), as in previous embodiments. 
     A rotation of the threaded rod  83 , in engagement with the threaded hole  82  of the base  81  of the hollow cylinder  85 , produces a lifting of the conical body  84 , which slides against the inclined surfaces  89  of the blocks  87 , producing the release thereof from the cylinder and the engagement against the inner surface  103  of the hole  101  ( FIG. 15 ) determining the locking of the fixing device  50 ″. 
     From what has been disclosed above, the advantages of the snow chain according to the invention are clear, whose device for fixing to the wheel can be easily mounted in the central hole of an alloy rim, ensuring uniform tensioning of the chain. 
     Naturally the invention is not limited to the particular embodiments previously described and illustrated in the accompanying drawings, but numerous detailed changes can be made thereto by the person skilled in the art, without thereby departing from the scope of the invention itself, as defined in the appended claims.