Patent Publication Number: US-2018037057-A1

Title: Safety device for a vehicle wheel

Description:
BACKGROUND OF THE INVENTION 
     Background 
     This invention relates to a safety device for a wheel assembly. 
     Truck, tractor, and trailer wheels pose a safety hazard because the rim or wheel studs of the wheel can fail when the vehicle is moving. This allows the wheel to fly free from the vehicle and endangers people and property. 
     This presents a need for safety devices that prevent wheels from flying away from trucks, tractors, and trailers when the wheel studs or wheel rim suffer mechanical failure. 
     Since this type of wheel rim and wheel stud failure is possible on many existing trucks, a desirable feature of this type of safety device is that it be capable of installation on existing truck, tractor, and trailer wheel assemblies. Further, it is desirable that a safety device for this purpose will not unduly interfere with the operation of, nor substantially increase the width of, the truck, tractor, or trailer. 
     SUMMARY 
     A safety device for a wheel assembly is an integral member with mounting holes for receiving axle studs of the wheel assembly to fix the integral member to the axle. The integral member has a radially extending portion which, when the integral member is fixed to the axle, overlaps the wheel studs of the wheel assembly but is free of any connection to the wheel studs. The integral member has tapered holes radially outbound of its mounting holes. In another embodiment, the integral member of the safety device has a cylindrical, interiorly threaded, sleeve portion and a radial portion extending radially outwardly from the sleeve portion with the radial portion having tapered holes radially outbound of the sleeve portion. 
     In accordance with an aspect, there is provided a safety device for a wheel assembly, said assembly comprising an axle, a wheel rim, and a wheel hub with a plurality of axle studs extending through holes in an outer end of the axle, and a plurality of wheel studs retaining the wheel rim, said safety device comprising: an integral member having a plurality of mounting holes for receiving said axle studs to fix said integral member to said axle; said integral member having a radially extending portion; said radially extending portion, when said integral member is fixed to said axle, overlapping the wheel studs; said integral member, when fixed to said axle, free of any connection to the wheel studs; and said integral member having a plurality of tapered holes radially outbound of said mounting holes. 
     In accordance with another aspect, there is provided a wheel assembly comprising: an axle; a wheel rim; a wheel hub from which a plurality of axle studs project and extend through holes in an outer end of the axle, and from which a plurality of wheel studs project and retain the wheel rim; an integral safety device having a plurality of mounting holes receiving said axle studs to fix said safety device to said axle; said safety device having a radially extending portion overlapping the wheel studs; said safety device free of any connection to the wheel studs; and said safety device having a plurality of tapered holes radially outbound of said mounting holes. 
     In accordance with a further aspect, there is provided a safety device for a wheel assembly, comprising: an integral member having a cylindrical, interiorly threaded, sleeve portion; said integral member having a radial portion extending radially outwardly from said sleeve portion; said radial portion having a plurality of tapered holes radially outbound of said sleeve portion. 
     In accordance with a yet further aspect, there is provided a wheel assembly comprising: a wheel rim; a rotating wheel hub; a plurality of wheel studs retaining said wheel rim to said wheel hub; an integral safety device comprising: an axially-extending interiorly threaded sleeve portion threaded to the rotating wheel hub; a radially extending portion, said radially extending portion overlapping the wheel studs; said integral member free of any connection to the wheel studs; said radially extending portion having a plurality of tapered holes radially outbound of said sleeve. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings which illustrate embodiments: 
         FIG. 1  is an exploded perspective view of a truck wheel assembly and safety device in accordance with an embodiment; 
         FIG. 2  is a cross-sectional assembled view of the truck wheel assembly and safety device of  FIG. 1 ; 
         FIG. 3  is a magnified view of the portion labeled  3  in  FIG. 2 ; 
         FIG. 4  is a front perspective view of the safety device of  FIG. 1 ; 
         FIG. 5  is a front view of the safety device of  FIG. 4 ; 
         FIG. 6  is a back view of the safety device of  FIG. 4 ; 
         FIG. 7  is a side view of the safety device of  FIG. 4 ; 
         FIG. 8  is a cross-sectional view of a trailer wheel having a safety device in accordance with a second embodiment; 
         FIG. 9  is a front perspective view of the safety device of  FIG. 8 ; 
         FIG. 10  is a back perspective view of the safety device of  FIG. 8 ; 
         FIG. 11  is a front view of the safety device of  FIG. 8 ; and 
         FIG. 12  is a back view of the safety device of  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 and 2 , in a first embodiment, a driving wheel assembly  20  has an axle with an axle shaft  22  which extends through a stationary axle housing  24  and terminates in an axle end cap  26 . A wheel hub  28  is supported for rotation on the axle housing  24  by bearings  30  and is attached to the outer end of the axle by means of axle studs  32  which are threaded to the wheel hub and pass through holes  34  in the axle end cap  26 . Wheel studs  36  protrude from wheel hub  28 , pass through holes  38  in wheel rims  40   a ,  40   b , and are joined to the wheel rims by nuts  42 . 
     A brake assembly—namely brake drums or disks with calipers (not shown)—is disposed within wheel rim  40   a.    
     As seen in  FIG. 2 , a safety device  50  abuts the axle end cap  26  of the axle. 
     Turning to  FIGS. 3 to 7 , the safety device  50  is an integral member in the nature of a radially extending disk which may be formed from aluminum at least ⅜″ thick. The safety device has countersunk mounting holes  52  extending about a central opening  54 . The safety device has tapered holes  56  positioned radially outbound of mounting holes  52  and arranged in a circular pattern. The tapered holes may have a taper angle of about 15° and taper from a larger diameter at the back face  58  of the safety device to a smaller diameter at the front face  59  of the safety device. 
     By way of example, the disk may be about ⅝″ thick and the tapered holes may taper from a diameter of about 3⅝″ at the back face of the safety device to a diameter of about 3¼″ at the front face of the safety device such that the tapered holes are about 10% larger at the back face of the safety device. 
     Returning to  FIGS. 1 and 2 , the safety device is positioned against the axle end cap  26  so that the axle studs  32  extend through the mounting holes  52  in the safety device. In this regard, the safety device is oriented so that the back face  58  of the safety device—having the wider diameter end of tapered holes  56 —faces the wheel hub  28 . Nuts  60  ( FIG. 2 ) are then threaded to the axle studs  32  to fixedly retain the safety device in abutting relationship with the axle end cap  26 . The radially extending safety device overlaps the wheel studs  36  but is free of any connection to the wheel studs  36 . Further, the safety device is constructed so that when it is mounted to the axle end cap, each tapered hole  56  is axially aligned with one wheel stud  36 . 
     Sometimes an axle cap  26  of a truck wheel assembly  20  has a protruding centre. The central hole  54  of the safety device  50  is sized for receiving any protruding portion of such an axle cap  26 . 
     As a truck fitted with the described truck wheel assembly and safety device is driven, the safety device rotates with the axle  22 . In consequence, the tapered holes  56  of the safety device cut the air, which results in air being forced through the tapered holes, from the smaller diameter end of the holes at the front face  59  of the safety device to their larger diameter end at the back face  58  of the safety device. With the back face  58  of the safety device facing the wheel hub  28 , the forced air flows inwardly to impact the brake assembly within the wheel rim. This cools the brake assembly which reduces brake fade and increases brake life. 
     Additionally, by axially aligning the tapered holes  56  with the wheel studs  36 , the tapered holes provide access points for removing the nuts  42  from the wheel studs  36 . Indeed, by judiciously sizing the minor diameter of the tapered holes, these holes may closely fit the extension piece of a tool used to remove nuts  42  in order to assist in maintaining alignment of the extension piece. 
     In a second embodiment, a safety device is provided for a truck idler wheel assembly as is typically found on a non-driven wheel, such as a trailer wheel. Referring to  FIG. 8 , in the second embodiment, a wheel hub  128  is mounted by bearings  130  to axle shaft  122  of wheel assembly  120 . A plurality of wheel studs  136  extend from the wheel hub  128  and pass through a wheel rim  140 . Nuts  142  hold the wheel rim to the wheel studs. The outer end of the exterior surface of the wheel hub  128  has a threaded portion  144  interrupted by a keyway  146 . The wheel hub  128  may be manufactured with such a thread and keyway or the thread may be die cut into a wheel hub already installed on a truck and the keyway machined into the threaded portion of the wheel hub. 
     A brake assembly (not shown) is disposed within the wheel rim  140 . 
     Referencing  FIGS. 9 to 12  along with  FIG. 8 , a safety device  150  is an integral member with a cylindrical sleeve portion  170  and a radial portion  172  proximate one end of the sleeve portion extending radially outwardly from the sleeve portion  170 . The sleeve portion  170  has interior threads  176  which threads are interrupted by a keyway  178 . The radial portion  172  has a plurality of tapered holes  156  radially outbound of the sleeve portion  170  and arranged in a circular pattern. The tapered holes may have a taper angle of about 15° and taper from a larger diameter at the back face  158  of the radial portion  172  to a smaller diameter at the front face  159  of the radial portion  172 . 
     Again, the integral safety device is preferably formed of aluminum, at least ⅝ inches thick. 
     By way of example, and similarly to the first embodiment, the radial portion  172  may be about ⅝″ thick and the tapered holes may taper from a diameter of about 3⅝″ at the back face of the radial portion of the safety device to a diameter of about 3¼″ at the front face of the radial portion of the safety device such that the tapered holes are about 10% larger at the back face. 
     With reference to  FIG. 8 , the safety device may be mounted by threading the sleeve portion  170  over the threaded portion of the wheel hub  128  such that the back surface  158  of the radial portion  172  faces the wheel hub. The sleeve portion is threaded to the wheel hub until the keyway  178  of the safety device is aligned with the keyway  146  of the wheel hub; a key  180  is then inserted into the aligned keyways to lock the sleeve to the wheel hub  128 . A bolt (not shown) is then threaded into threaded hole  181  ( FIG. 12 ) of the safety device so that the head of the bolt retains the key  180  in place. It will be apparent that, when the safety device is mounted to the wheel hub  128 , the radial portion  172  of the safety device overlaps the wheel studs  136  but is free of any connection to the wheel studs  136 . Further, the safety device can be constructed so that when it is mounted (and locked) to the wheel hub, each tapered hole  156  is axially aligned with one wheel stud  136  in order to facilitate torquing, re-torquing and removal of the nuts  142 , as has been described in conjunction with the first embodiment. 
     An axle cap  182  covers the outer end of the axle  122  and is bolted by bolts  184  to wheel hub  128 . The safety device  150  defines a central hole  154  that receives the axle cap  182 . 
     In use, as a truck idler wheel mounted to rim  140  rotates, the wheel hub  128  rotates on (stationary) axle  122 . The safety device  150 , which is locked to the wheel hub, rotates with the wheel hub. In the event of failure of the wheel studs  136  or the wheel rim  140 , the safety device acts to prevent the wheel and wheel rim from leaving the vehicle. 
     It will be apparent to those skilled in the art, that certain components of conventional truck wheel assemblies have been omitted from the drawings and from this description. 
     Those skilled in the art will find obvious certain variations of the disclosed embodiments. For example, the direction of the taper of tapered holes  56 ,  156  in the safety device could be reversed such that the large diameter end of these holes is at the front face of the safety device. With this modification, air will be drawn away from the wheel hub and rim rather than being forced toward the hub and rim. With this modification, the safety device will still act to cool the brakes. More specifically, as the brakes heat up, they will heat the air around the hub and rim: by drawing off this hot air, the hot air will be replaced with cooler air and the brakes will be cooled.