BACKGROUND 
       [0001]    Boltless aircraft wheels, also known as lock ring aircraft wheels, often comprise a wheel base, a side rim, and a single lock ring. The wheel base is typically coupled to the aircraft brake for applying torque to cause the aircraft to decelerate. The side rim is typically coupled about a circumference of the wheel base and is often at least partially in contact with a tire. A single lock ring is typically placed in between the wheel base and the side rim for retaining the side rim to the wheel base and transferring torque from the wheel base to the side rim. However, in applications having large brakes (e.g., those with wheel bases nineteen inches in diameter or greater), a wheel having a single lock ring may be prone to a wheel-skid. A wheel-skid is an event in which the tire and side rim continue to roll at ground speed while the wheel base is locked to the brake and not rotating. A wheel-skid is in contrast to a tire-skid, where the tire is stationary, and sliding, relative to the runway. 
         [0002]    To reduce the likelihood of a wheel-skid, lock ring wheels may incorporate multiple lock rings. Depending on the geometry of the lock rings, multiple lock rings may have more contact points with the wheel base and the side rim than does a single lock ring. Increasing the number of contact points between the lock rings and the side rim, and between the lock rings and the wheel base, increases the number of pathways in which torque is transferred from the wheel base to the side rim. By increasing the number of torque pathways between the wheel base and the side rim, the possibility that the side rim will slide around the wheel base and produce a wheel-skid is reduced. However, if the multiple lock rings are incorrectly installed between the wheel base and side rim, or if one of the lock rings is not included in the assembly, the number of torque pathways between the wheel base and the side rim may be reduced and the ability of the remaining lock ring(s) to retain the side rim may be adversely affected. Detecting incorrect assembly of the lock rings with the wheel base and side rim may be difficult since the lock rings are confined between and mostly covered by the side rim and wheel base, impairing visual inspection of the lock ring assembly. Detecting incorrect assembly of the lock rings may also be difficult as the wheel may appear visually and operationally functional despite incorrect assembly of the lock rings. 
       SUMMARY 
       [0003]    According to the present invention, a wheel assembly includes a wheel base and a side rim. The side rim is disposed about the wheel base and includes an inside surface and a recess formed on the inside surface. An air seal is disposed between the wheel base and the inside surface of the side rim. A locking mechanism secures the side rim onto the wheel base and prevents the side rim from sliding axially off the wheel base. The locking mechanism is also configured to prevent the air seal from disengaging the inside surface and allowing air to exit the wheel assembly between the wheel base and the side rim when the locking mechanism is properly installed. The locking mechanism is also configured to permit the air seal to disengage the inside surface and allow air to exit the wheel assembly between the wheel base and the side rim when the locking mechanism is not properly installed. 
         [0004]    In another embodiment of the present invention, a method for assembling a wheel includes placing a wheel base inside a tire, the wheel base having an air seal seat. A side rim is placed inside the tire around the wheel base. The side rim includes a recess formed on an inside surface of the side rim. The side rim is moved on the wheel base to expose the air seal seat. An air seal is placed around the wheel base and inside the air seal seat. A lock ring assembly is inserted inside a cavity between the wheel base and the side rim, and the tire is inflated. Faulty assembly of the wheel is detected if the air seal disengages the inside surface upon mis-installation of the lock ring assembly such that air exits the wheel between the wheel base and the side rim, thereby preventing inflation of the tire. 
         [0005]    In another embodiment of the present invention, a wheel assembly includes a wheel base and a side rim, the side rim being disposed around the wheel base. The side rim includes an inside surface and a recess formed on the inside surface. A cavity disposed between the wheel base and the side rim. An air seal is disposed between the wheel base and the inside surface of the side rim, and disposed axially between the recess and the cavity. A multipart lock ring assembly is disposed within the cavity. The multipart lock ring assembly is configured to prevent the air seal from disengaging the inside surface and allowing air to exit the wheel assembly between the wheel base and the side rim when the multipart lock ring assembly is properly installed. The multipart lock ring assembly is also configured to permit the air seal to disengage the inside surface and allow air to exit the wheel assembly between the wheel base and the side rim when the multipart lock ring assembly is not properly installed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a perspective view of a wheel assembly according to the present invention. 
           [0007]      FIG. 2  is a cross-sectional view of the wheel assembly of  FIG. 1  taken along line A-A. 
           [0008]      FIG. 3  is an enlarged cross-sectional view of the wheel assembly of  FIG. 1  showing a first lock ring and a second lock ring. 
           [0009]      FIG. 4  is an enlarged cross-sectional view of the wheel assembly of  FIG. 1  missing the second lock ring. 
           [0010]      FIG. 5  is an enlarged cross-sectional view of the wheel assembly of  FIG. 1  missing the first lock ring. 
           [0011]      FIG. 6  is a perspective view of a side rim from the wheel assembly of  FIG. 1 . 
           [0012]      FIG. 7  is an enlarged cross-sectional view of the side rim of  FIG. 6  taken along line B-B. 
           [0013]      FIG. 8  is a perspective view of another embodiment a side rim according to the present invention. 
           [0014]      FIG. 9  is an enlarged cross-sectional view of the side rim of  FIG. 8  taken along line C-C. 
           [0015]      FIG. 10  is a perspective view of another embodiment a side rim according to the present invention. 
           [0016]      FIG. 11  is an enlarged cross-sectional view of the side rim of  FIG. 10  taken along line D-D. 
           [0017]      FIG. 12  is an enlarged cross-sectional view of the wheel assembly with another embodiment of the first lock ring and the second lock ring according to the present invention. 
           [0018]      FIG. 13  is an enlarged cross-sectional view of the wheel assembly with another embodiment of the first lock ring and the second lock ring according to the present invention. 
           [0019]      FIG. 14  is an enlarged cross-sectional view of the wheel assembly with another embodiment of the first lock ring and the second lock ring according to the present invention. 
           [0020]      FIG. 15  is an enlarged cross-sectional view of the wheel assembly with another embodiment of the first lock ring and the second lock ring according to the present invention. 
           [0021]      FIG. 16  discloses a diagram of a method for assembling a wheel. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    The present invention provides an assembly and method for reducing incorrect assembly of multiple lock rings between the wheel base and the side rim of a wheel assembly. The present invention reduces incorrect assembly of the lock rings by releasing inflation pressure in the wheel assembly when one or more lock rings are missing and by preventing installation of a retaining ring if one or more lock rings are improperly installed between the wheel base and the side rim. Because the wheel assembly is not capable of holding pressurized air when one or more of the lock rings are missing, the wheel assembly cannot be functional until the lock rings are properly installed. The present invention releases pressurized air from the wheel assembly through a recess formed in the side rim, which exposes an air seal between the side rim and wheel base when one or more of the lock rings are missing. Only proper installation of the lock rings will allow inflation of the wheel assembly. 
         [0023]      FIG. 1  is a perspective view of a wheel assembly  10  according to the present invention, and  FIG. 2  is a cross-sectional view of the wheel assembly  10  of  FIG. 1  taken along line A-A. Wheel assembly  10  includes wheel base  12 , side rim  14 , axis  16 , air seal  18 , cavity  20 , first lock ring  22 , second lock ring  24 , and retaining ring  25 . In the embodiment of  FIGS. 1 and 2 , wheel base  12  includes hub  26 , spokes  28 , tubewell  30 , and inboard flange  32 . Side rim  14  includes outboard flange  34 , inside surface  36 , and recess  38 . Wheel assembly  10  also includes tire  40 . 
         [0024]    Hub  26  is disposed radially inward from tubewell  30  and is the point of contact between an axle of an aircraft or vehicle and wheel assembly  10 . Spokes  28  extend radially outward from hub  26  and connect tubewell  30  to hub  26 . When wheel assembly  10  is mounted onto an aircraft or any other vehicle, inboard is defined as the direction facing towards the center of the aircraft or vehicle structure and outboard is defined as the direction facing outward or away from the center of the aircraft or vehicle structure. In this embodiment, inboard and outboard refer to specific directions, but in alternate embodiments, they may be reversed. Inboard flange  32  is disposed on tubewell  30  and extends radially outward from tubewell  30  and extends axially inboard. Side rim  14  is disposed around the circumference of tubewell  30  opposite inboard flange  32 . Side rim  14  is coaxial with wheel base  12 , both being centered about axis  16 . Outboard flange  34  extends radially outward from side rim  14  and extends axially outboard. Tire  40  is disposed around tubewell  30  between inboard flange  32  and outboard flange  34 . Inside surface  36  of side rim  14  faces tubewell  30  of wheel base  12 . Recess  38  is formed on inside surface  36 . Cavity  20  is disposed between side rim  14  and tubewell  30  of wheel base  12  and houses first lock ring  22  and second lock ring  24 . Retaining ring  25  axially retains first lock ring  22  and second lock ring  24  inside cavity  20 . First lock ring  22  is disposed inside cavity  20  axially inboard from second lock ring  24 . Air seal  18  is disposed circumferentially around tubewell  30  of wheel base  12  and is disposed between tubewell  30  of wheel base  12  and inside surface  36  of side rim  14 . Air seal  18  is disposed axially on inside surface  36  between recess  38  and cavity  20 . In the embodiment of  FIGS. 1 and 2 , air seal  18  is an  0 -ring. 
         [0025]    When first lock ring  22  and second lock ring  24  are correctly assembled inside cavity  20 , first lock ring  22  and second lock ring  24  work together as a locking mechanism to prevent side rim  14  from sliding axially outboard off wheel base  12 . When first lock ring  22  and second lock ring  24  are correctly assembled inside cavity  20 , first lock ring  22  and second lock ring  24  transmit torque from wheel base  12  to side rim  14 , such that side rim  14  rotates in unison with wheel base  12 . As disclosed below in the description of FIGS.  3  and  12 - 15 , first lock ring  22  and second lock ring  24  form multiple contact points and torque pathways between wheel base  12  and side rim  14 , thereby reducing the probability of wheel-skid occurring between wheel base  12  and side rim  14 . The discussion in the Background section describes wheel-skid and why it is undesirable. Additionally, when first lock ring  22  and second lock ring  24  are correctly assembled inside cavity  20 , air seal  18  engages inside surface  36  of side rim  14  and tubewell  30  of wheel base  12 , preventing air from leaking out of wheel assembly  10  between side rim  14  and wheel base  12  as tire  40  is inflated. As described below in the description of  FIGS. 3-5 , when first lock ring  22  or second lock ring  24  is missing from inside cavity  20 , side rim  14  moves axially outboard relative to wheel base  12  such that inside surface  36  disengages air seal  18 , thereby allowing air to leak out of wheel assembly  10  between side rim  14  and wheel base  12 . 
         [0026]      FIG. 3  is an enlarged cross-sectional view of wheel assembly  10  of  FIG. 1 , showing first lock ring  22  and second lock ring  24 .  FIG. 4  is an enlarged cross-sectional view of wheel assembly  10  of  FIG. 1  missing second lock ring  24 .  FIG. 5  is an enlarged cross-sectional view of wheel assembly  10  of  FIG. 1  missing first lock ring  22 . Wheel assembly  10  includes wheel base  12 , side rim  14 , air seal  18 , cavity  20 , first lock ring  22 , second lock ring  24 , and retaining ring  25 . In the embodiment of  FIGS. 3-5 , wheel base  12  includes tubewell  30 , tapered surface  42 , and air seal seat  44 . Side rim  14  includes outboard flange  34 , inside surface  36 , recess  38 , and retaining ring groove  39 . Cavity  20  includes top surface  46 , bottom surface  48 , first side surface  50 , and second side surface  52 . First lock ring  22  includes mating surface  54 , and second lock ring  24  includes mating surface  56 . In the embodiment of  FIGS. 3-5 , wheel assembly  10  also includes tire  40  and air  58 . 
         [0027]    In  FIGS. 3-5 , components of like numbering with the components of  FIGS. 1 and 2  are assembled as discussed above with reference to  FIGS. 1-2 . Tapered surface  42  is formed in tubewell  30  of wheel base  12  and extends radially inward as it extends axially outboard towards cavity  20 . Tapered surface  42  stops short of cavity  20  and does not extend into cavity  20 . Air seal seat  44  is disposed at an outboard end of tapered surface  42  and is cut to match the shape of air seal  18 . Top surface  46  of cavity  20  is formed on inside surface  36  of side rim  14 . Bottom surface  48  of cavity  20  is formed on tubewell  30  of wheel base  12 . Top surface  46  is parallel to bottom surface  48 . First side surface  50  of cavity  20  is formed on inside surface  36  of side rim  14  and extends between inside surface  36  and top surface  46 . Second side surface  52  of cavity  20  is formed on tubewell  30  of wheel base  20 . Second side surface  52  of cavity  20  extends radially upward and axially outboard from bottom surface  48  of cavity  20 . In the embodiment of  FIGS. 3-5 , first side surface  50  is parallel to second side surface  52 . 
         [0028]    When first lock ring  22  is correctly installed inside cavity  20 , first lock ring  22  contacts bottom surface  48  and first side surface  50  of cavity  20 . Because first lock ring  22  is contacting both side rim  14  (at first side surface  50 ) and wheel base  12  (at bottom surface  48 ), first lock ring  22  functions as a torque pathway between wheel base  12  and side rim  14 . When second lock ring  24  is correctly installed inside cavity  20 , second lock ring  24  contacts top surface  46  and second side surface  52  of cavity  20 . Because second lock ring  24  is contacting both side rim  14  (at top surface  46 ) and wheel base  12  (at second side surface  52 ), second lock ring  24  functions as another torque pathway between wheel base  12  and side rim  14 . 
         [0029]    Second lock ring  24  is disposed axially outboard from first lock ring  22  inside cavity  20 . Mating surface  56  of second lock ring  24  contacts mating surface  54  of first lock ring  22 . In the embodiment of  FIGS. 3-5 , mating surfaces  54  and  56  are oriented perpendicularly relative first side surface  50  and second side surface  52  of cavity  20 . By being oriented perpendicularly to first side surface  50  and second side surface  52 , mating surfaces  54  and  56  are wedged against each other by side rim  14 , side rim  14  being acted upon by the air pressure inside inflated tire  40 . By being wedged against each other, mating surfaces  54  and  56  create an additional torque pathway between wheel base  12  and side rim  14 , the torque pathway passing through both first lock ring  22  and second lock ring  24 . 
         [0030]    When first lock ring  22  and second lock ring  24  are correctly assembled inside cavity  20 , first lock ring  22  and second lock ring  24  axially limit the outboard travel of side rim  14  with respect to wheel base  12  when the tire  40  is pressurized. When tire  40  is inflated and side rim  14  is correctly positioned, air seal  18  contacts inside surface  36  of side rim  14  between recess  38  and first side wall  50  of cavity  20 . When air seal  18  contacts inside surface  36 , air  58  inside of tire  40  is unable to escape out of wheel assembly  10  between side rim  14  and wheel base  12 . An operator who is assembling wheel assembly  10  can detect proper assembly of lock rings  22  and  24  inside wheel assembly  10  when the operator fills wheel assembly  10  with air  58  and wheel assembly  10  remains pressurized and retaining ring  25  can be installed inside retaining ring groove  39  on side rim  14 . 
         [0031]    First lock ring  22  and second lock ring  24  may be color coded to visually assist an operator in correctly assembling first lock ring  22  and second lock ring  24  inside cavity  20 . As an example, mating surface  54  of first lock ring  22  and mating surface  56  of second lock ring  24  may both be dyed the same color, such as red, while all other surfaces of both first lock ring  22  and second lock ring  24  may be dyed a different color, such as gray. An operator who correctly assembles first lock ring  22  and second lock ring  24  inside cavity  20  should not be able to see any red dye upon visual inspection because mating surface  54  will be mated against mating surface  56 . If an operator is able to see red dye after installing first lock ring  22  and second lock ring  24  inside cavity  20 , the operator will know that mating surface  54  has not been mated with mating surface  56 , and that first lock ring  22  and second lock ring  24  have been incorrectly installed inside cavity  20 . This color coding feature can be implemented on any or all of the embodiments disclosed herein. 
         [0032]      FIGS. 4 and 5  show wheel assembly  10  in situations where first lock ring  22  and second lock ring  24  have been improperly installed inside cavity  20 . In  FIG. 4 , first lock ring  22  has been installed inside cavity  20 , but second lock ring  24  was omitted from cavity  20  during assembly of wheel assembly  10 . When tire  40  is pressurized, the pressure inside tire  40  pushes tire  40  against side rim  14 , causing side rim  14  to push against first lock ring  22 . Because second lock ring  24  was omitted, first lock ring  22  slides inside cavity  20  along bottom surface  48  until first lock ring  22  contacts second side surface  52 . As first lock ring  22  slides inside cavity  20 , side rim  14  also slides outboard until air seal  18  disengages inside surface  36 . When air seal  18  disengages inside surface  36 , air  58  escapes from wheel assembly  10  between side rim  14  and wheel base  12 . As a result of air  58  escaping wheel assembly  10 , tire  40  rapidly deflates or is unable to fully inflate at all. An operator who assembles wheel assembly  10  yet fails to include second lock ring  24  inside cavity  20  will be able to detect an assembly error in wheel assembly  10  through the operator&#39;s inability to inflate tire  40  without tire  40  going flat. 
         [0033]    In  FIG. 5 , second lock ring  24  has been installed inside cavity  20 , but first lock ring  22  was omitted from cavity  20  during assembly of wheel assembly  10 . When tire  40  is pressurized, the pressure inside tire  40  pushes tire  40  against side rim  14 , causing side rim  14  to slide on tubewell  30  until first side surface  50  contacts second lock ring  24 . As side rim  14  slides outboard on tubewell  30 , air seal  18  disengages inside surface  36 . When air seal  18  disengages inside surface  36 , air  58  escapes from wheel assembly  10  between side rim  14  and wheel base  12 . As a result of air  58  escaping wheel assembly  10 , tire  40  rapidly loses pressure and is unable to fully inflate. An operator who assembles wheel assembly  10  yet fails to include first lock ring  22  inside cavity  20  will be able to detect an assembly error in wheel assembly  10  through the operator&#39;s inability to inflate tire  40  without tire  40  going flat. The operator may also be able to detect an assembly error in wheel assembly  10  through the operator&#39;s inability to install retaining ring  25  inside retaining ring groove  39  because first lock ring  22  was improperly installed, causing second lock ring  24  to block retaining ring groove  39 . 
         [0034]      FIGS. 6 and 7  will now be discussed concurrently.  FIG. 6  is a perspective view of side rim  14  from the embodiment of wheel assembly  10  in  FIG. 1 .  FIG. 7  is an enlarged cross-sectional view of side rim  14  of  FIG. 6  taken along line B-B. Side rim  14  includes outboard flange  34 , inside surface  36 , recesses  38 , inboard end  60 , and outboard end  62 . In the embodiment of  FIGS. 6 and 7 , side rim  14  also includes top surface  46  and first side surface  50  for forming cavity  20  as discussed above in the description of  FIGS. 3-5 . 
         [0035]    In  FIGS. 6 and 7 , components of like numbering with the components of  FIGS. 3-5  are assembled as discussed above with reference to  FIGS. 3-5 . Side rim  14  is generally an annular ring that extends axially from inboard end  60  to outboard end  62 . Recesses  38  are formed on inside surface  36  and are spaced circumferentially apart from each other on inside surface  36 . Each recess  38  is an axial groove that extends axially on inside surface  36  between inboard end  60  and first side surface  50 . Recesses  38  do not contact first side surface  50 . Each recess  38  may slope radially outward from inside surface  36  as each recess extends outboard. Recesses  38  may also be curved such that they do not form any sharp angles with inside surface  36 . By sloping and curving recesses  38 , the formation of stress concentrations may be reduced in side rim  14  as it is used in wheel assembly  10  as described above in  FIGS. 1-5 . By forming multiple recesses  38  that are circumferentially spaced apart on inside surface  36 , and by forming multiple recesses  38  with radii smaller than a minimum bending radius of the air seal  18 , air pressure inside wheel assembly  10  cannot lift and push air seal  18 , shown in  FIGS. 1-5 , into recesses  38 . Because circumferentially spaced apart recesses  38  and inside surface  36  prevent air seal  18  from entering recesses  38 , recesses  38  remain clear and open and air  58 , shown in  FIGS. 4-5 , is able to escape wheel assembly  10  when first lock ring  22  or second lock ring  24 , shown in  FIGS. 3-5 , is left out of cavity  20 , or incorrectly installed. 
         [0036]      FIGS. 8 and 9  will now be discussed concurrently.  FIG. 8  is a perspective view of another embodiment of side rim  14 .  FIG. 9  is an enlarged cross-sectional view of side rim  14  of  FIG. 8  taken along line C-C. Side rim  14  includes outboard flange  34 , inside surface  36 , recess  38 , inboard end  60 , and outboard end  62 . In the embodiment of  FIGS. 8 and 9 , side rim  14  also includes top surface  46  and first side surface  50  for forming cavity  20  as discussed above in the description of  FIGS. 3-5 . 
         [0037]    In  FIGS. 8 and 9 , components of like numbering with the components of  FIGS. 6-7 , with the exception of recess  38 , are assembled as discussed above with reference to  FIGS. 6-7 . In the embodiment of  FIGS. 8 and 9 , recess  38  is an annular groove formed on inside surface  36  that extends axially on inside surface  36  between inboard end  60  and first side surface  50 . Recess  38  does not contact first side surface  50 . Recess  38  may slope radially outward from inside surface  36  as recess  38  extends outboard. Recess  38  may also include curved edges such that recess  38  does not form any sharp angles with inside surface  36 . By sloping and curving recess  38 , the formation of stress concentrations may be reduced in side rim  14  as it is used in wheel assembly  10  as described above in  FIGS. 1-5 . As described above in  FIGS. 3-5 , recess  38  allows air  58  to escape wheel assembly  10  past air seal  18  when first lock ring  22  or second lock ring  24  is left out of cavity  20 , or incorrectly installed. 
         [0038]      FIGS. 10 and 11  will now be discussed concurrently.  FIG. 10  is a perspective view of another embodiment of side rim  14 .  FIG. 11  is an enlarged cross-sectional view of side rim  14  of  FIG. 10  taken along line D-D. Side rim  14  includes outboard flange  34 , inside surface  36 , recesses  38 , inboard end  60 , and outboard end  62 . In the embodiment of  FIGS. 10 and 11 , side rim  14  also includes top surface  46  and first side surface  50  for forming cavity  20  as discussed above in the description of  FIGS. 3-5 . 
         [0039]    In  FIGS. 10 and 11 , components of like numbering with the components of  FIGS. 6-7 , with the exception of recesses  38 , are assembled as discussed above with reference to  FIGS. 6-7 . Side rim  14  is generally an annular ring that extends axially from inboard end  60  to outboard end  62 . Recesses  38  are formed on inside surface  36  and are spaced circumferentially apart from each other on inside surface  36 . Recesses  38  do not contact first side surface  50 . Each recess  38  is a dimple formed on inside surface  36  between inboard end  60  and first side surface  50 . Each recess  38  may be a semispherical dimple. By forming multiple recesses  38  that are circumferentially spaced apart on inside surface  36 , and by forming multiple recesses  38  with radii smaller than a minimum bending radius of the air seal  18 , air pressure inside wheel assembly  10  cannot lift and push air seal  18 , shown in  FIGS. 1-5 , into recesses  38 . Because circumferentially spaced apart recesses  38  and inside surface  36  prevent air seal  18  from entering recesses  38 , recesses  38  remain clear and open and air  58 , shown in  FIGS. 4-5 , is able to escape wheel assembly  10  when first lock ring  22  or second lock ring  24 , shown in  FIGS. 3-5 , is left out of cavity  20 , or incorrectly installed. A large number of permutations of lock ring cross-section are possible, with a sampling of exemplary embodiments shown in  FIGS. 12-15 . 
         [0040]      FIG. 12  is an enlarged cross-sectional view of wheel assembly  10  with another embodiment of first lock ring  22  and second lock ring  24 . Wheel assembly  10  includes wheel base  12 , side rim  14 , air seal  18 , cavity  20 , first lock ring  22 , second lock ring  24 , and retaining ring  25 . In the embodiment of  FIG. 12 , wheel base  12  includes tubewell  30 , tapered surface  42 , and air seal seat  44 . Side rim  14  includes outboard flange  34 , inside surface  36 , recess  38 , and retaining ring groove  39 . Cavity  20  includes top surface  46 , bottom surface  48 , first side surface  50 , and second side surface  52 . First lock ring  22  includes mating surface  54  and hollow core  64 . Second lock ring  24  includes mating surface  56  and hollow core  66 . 
         [0041]    In  FIG. 12 , components of like numbering with the components of  FIGS. 3-5  are assembled as discussed above with reference to  FIGS. 3-5 . Hollow core  64  is formed inside first lock ring  22  and hollow core  66  is formed inside second lock ring  24 . Hollow core  64  reduces the weight of first lock ring  22 , and hollow core  66  reduces the weight of second lock ring  24 . Reducing the weight of first lock ring  22  and second lock ring  24  reduces the overall weight of wheel assembly  10  and any vehicle attached to wheel assembly  10 , resulting in increased fuel efficiency of the vehicle. 
         [0042]    Mating surface  54  of first lock ring  22  and mating surface  56  of second lock ring  24  may also be connected together as a subassembly prior to being inserted inside cavity  20 . A connector that could connect mating surface  54  to mating surface  56  may include an adhesive or glue applied between mating surface  54  and mating surface  56 . The connector may also include a tie, such as a zip tie, that connects first lock ring  22  to second lock ring  24  such that mating surface  54  abuts mating surface  56 . Holes or slots may be formed in first lock ring  22  and second lock ring  22  to accommodate a tie. Connecting first lock ring  22  to second lock ring  24  prior to installing them inside cavity  20  may simplify the assembling process of wheel assembly  10  and ensures that neither first lock ring  22  nor second lock ring  24  is accidentally excluded from wheel assembly  10 . 
         [0043]      FIG. 13  is an enlarged cross-sectional view of wheel assembly  10  with another embodiment of first lock ring  22  and second lock ring  24 . Wheel assembly  10  includes wheel base  12 , side rim  14 , air seal  18 , cavity  20 , first lock ring  22 , second lock ring  24 , and retaining ring  25 . In the embodiment of  FIG. 13 , wheel base  12  includes tubewell  30 , tapered surface  42 , and air seal seat  44 . Side rim  14  includes outboard flange  34 , inside surface  36 , recess  38 , and retaining ring groove  39 . Cavity  20  includes top surface  46 , bottom surface  48 , first side surface  50 , and second side surface  52 . First lock ring  22  includes short side  82 , long side  84 , perpendicular side  86 , and angled side  88 . Second lock ring  24  includes short side  90 , long side  92 , perpendicular side  94 , and angled side  96 . 
         [0044]    In  FIG. 13 , components of like numbering with the components of  FIGS. 3-5  are assembled as discussed above with reference to  FIGS. 3-5 . Referring to the embodiment of first lock ring  22  in  FIG. 13 , short side  82  is disposed opposite and parallel to long side  84 . Short side  82  is shorter in length than long side  84 . Perpendicular side  86  extends perpendicularly between short side  82  and long side  84 . Angled side  88  is opposite perpendicular side  86  and extends non-perpendicularly from short side  82  to long side  84 . Angled side  88  is longer in length than perpendicular side  86 . Together, short side  82 , long side  84 , perpendicular side  86 , and angled side  88  give first lock ring  22  a cross-sectional profile that is generally a trapezoid. First lock ring  22  is disposed inside cavity  20  such that long side  84  contacts first side surface  50  of cavity  20 , and angled side  88  contacts bottom surface  48  of cavity  20 . Referring now to the configuration of second lock ring  24  in the embodiment of  FIG. 13 , short side  90  is disposed opposite and parallel to long side  92 . Short side  90  is shorter in length than long side  92 . Perpendicular side  94  extends perpendicularly between short side  90  and long side  92 . Angled side  96  is opposite perpendicular side  94  and extends non-perpendicularly from short side  90  to long side  92 . Angled side  96  is longer in length than perpendicular side  94 . Together, short side  90  long side  92 , perpendicular side  94 , and angled side  96  give first lock ring  22  a cross-sectional profile that is generally a trapezoid. Second lock ring  22  is disposed inside cavity  20  such that long side  92  contacts second side surface  52  of cavity  20  and angled side  96  contacts top surface  46  of cavity  20 . Perpendicular surface  94  of second lock ring  24  contacts and mates with perpendicular surface  86  of first lock ring  22 . The mating function between perpendicular surface  94  of second lock ring  24  and perpendicular surface  86  of first lock ring  22  is similar to that of mating surfaces  54  and  56  shown in  FIG. 3  and described above. In the embodiment of  FIG. 13 , first lock ring  22  and second lock ring  24  both function similarly to the embodiment of first lock ring  22  and second lock ring  24  shown in  FIG. 3 . However, the embodiment of first lock ring  22  and second lock ring  24  in  FIG. 13  are lighter in weight than the embodiment of  FIG. 3  and occupy less space inside cavity  20 . Reducing the weight of first lock ring  22  and second lock ring  24  reduces the overall weight of wheel assembly  10  and increases the fuel efficiency of any vehicle that utilizes wheel assembly  10 . 
         [0045]      FIG. 14  is an enlarged cross-sectional view of wheel assembly  10  with another embodiment of first lock ring  22  and second lock ring  24  according to the present invention. Wheel assembly  10  includes wheel base  12 , side rim  14 , air seal  18 , cavity  20 , first lock ring  22 , second lock ring  24 , and retaining ring  25 . In the embodiment of  FIG. 14 , wheel base  12  includes tubewell  30 , tapered surface  42 , and air seal seat  44 . Side rim  14  includes outboard flange  34 , inside surface  36 , recess  38 , and retaining groove  39 . Cavity  20  includes top surface  46 , bottom surface  48 , first side surface  50 , and second side surface  52 . First lock ring  22  includes short side  82 , long side  84 , perpendicular side  86 , angled side  88 , first annular channel  98 , and second annular channel  100 . Second lock ring  24  includes short side  90 , long side  92 , perpendicular side  94 , angled side  96 , first annular channel  102 , and second annular channel  104 . 
         [0046]    In  FIG. 14 , components of like numbering with the components of  FIG. 13  are assembled as discussed above with reference to  FIG. 13 . Referring to the embodiment of first lock ring  22  in  FIG. 14 , first annular channel  98  is formed on short side  82  of first lock ring  22 . Second annular channel  100  is formed on angled side  88  of first lock ring  22 . First annular channel  98  and second annular channel  100  reduce the weight of first lock ring  22  and increase the flexibility of first lock ring  22 . In the embodiment of second lock ring  24 , shown in  FIG. 14 , first annular channel  102  is formed on short side  90  of second lock ring  24 . Second annular channel  104  is formed on angled side  96  of second lock ring  24 . First annular channel  102  and second annular channel  104  reduce the weight of second lock ring  24  and increase the flexibility of second lock ring  24 . 
         [0047]    Reducing the weight of first lock ring  22  and second lock ring  24  reduces the overall weight of wheel assembly  10  and increases the fuel efficiency of any vehicle that utilizes wheel assembly  10 . Increasing the flexibility of first lock ring  22  and second lock ring  24  also helps to ensure that first lock ring  22  and second lock ring  24  have multiple contact points with wheel base  12  and side rim  14 . 
         [0048]      FIG. 15  is an enlarged cross-sectional view of wheel assembly  10  with another embodiment of first lock ring  22  and second lock ring  24  according to the present invention. Wheel assembly  10  includes wheel base  12 , side rim  14 , air seal  18 , cavity  20 , first lock ring  22 , second lock ring  24 , and retaining ring  25 . In the embodiment of  FIG. 15 , wheel base  12  includes tubewell  30 , tapered surface  42 , and air seal seat  44 . Side rim  14  includes outboard flange  34 , inside surface  36 , recess  38 , and retaining ring groove  39 . Cavity  20  includes top surface  46 , bottom surface  48 , first side surface  50 , and second side surface  52 . First lock ring  22  includes short side  82 , long side  84 , perpendicular side  86 , angled side  88 , first annular channel  98 , second annular channel  100 , and prong  101 . Second lock ring  24  includes short side  90 , long side  92 , perpendicular side  94 , angled side  96 , first annular channel  102 , second annular channel  104 , and prong  105 . 
         [0049]    In  FIG. 15 , components of like numbering with the components of  FIG. 14  are assembled as discussed above with reference to  FIG. 14 . Prong  101  is formed on perpendicular side  86  of first lock ring  22 . Prong  101  extends axially outboard and radially outward from perpendicular side  86  of first lock ring  22 . Prong  105  is formed on perpendicular side  94  of second lock ring  24 . Prong  105  extends axially inboard as it extends radially inward from perpendicular side  94  of second lock ring  24 . Inside cavity  20 , perpendicular side  86  and short side  82  of first lock ring  22  mate and interlock with prong  105  and perpendicular side  94  of second lock ring  24 . Perpendicular side  94  and short side  90  of second lock ring  24  mates and interlocks with prong  101  and perpendicular side  86  of first lock ring  22 . Prong  101  and prong  105  prevent perpendicular surface  86  of first lock ring  22  and perpendicular surface  94  of second lock ring  24  from slipping against each other. By preventing perpendicular surfaces  86  and  94  from slipping against each other, prong  101  of first lock ring  22  and prong  105  of second lock ring  24  ensure that at least one contact point is maintained between first lock ring  22  and second lock ring  24 . Maintaining contact points between first lock ring  22  and second lock ring  24  allows toque to be transferred from wheel base  12  across both first lock ring  22  and second lock ring  24  to side rim  14 . 
         [0050]      FIG. 16  discloses a diagram of method  114 , which begins with placing a wheel base inside a tire (step  116 ). The wheel base includes an air seal seat. A side rim is placed inside the tire around the wheel base (step  118 ). The side rim includes a recess formed on an inside surface of the side rim. The side rim is moved inboard on the wheel base to expose the air seal seat (step  120 ). An air seal is placed around the wheel base and inside the air seal seat (step  122 ). A lock ring assembly is inserted inside a cavity between the wheel base and the side rim (step  124 ). The tire is inflated (step  126 ). Faulty assembly of the wheel is detected if the air seal disengages, or fails to engage, the inside surface upon mis-installation of the lock ring assembly such that air exits the wheel between the wheel base and the side rim thereby preventing inflation of the tire (step  128 ). 
         [0051]    In view of the foregoing description, it will be recognized that the present disclosure provides numerous advantages and benefits. For example, the present disclosure provides wheel assembly with first lock ring  22  and second lock ring  24  between wheel base  12  and side rim  14 . First lock ring  22  and second lock ring  24  provide more torque pathways between wheel base  12  and side rim  14  than wheel assemblies in the prior art that only include a single lock ring. Because first lock ring  22  and second lock ring  24  provide more toque pathways between wheel base  12  and side rim  14 , the probability of wheel-skid is reduced. Furthermore, side rim  14  includes recess  38  which allows air  58  to escape wheel assembly  10  when first lock ring  22  or second lock ring  24  is not properly installed between wheel base  12  and side rim  14 . Because wheel assembly  10  is unable to remain pressurized when first lock ring  22  or second lock ring  24  is incorrectly installed, the probability that wheel assembly  10  will be incorrectly assembled and subsequently used is reduced. By reducing the use of incorrectly assembled wheel assemblies  10 , consumer safety is enhanced. 
         [0052]    While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
A wheel assembly includes a wheel base and a side rim disposed about the wheel base. A recess is formed on an inside surface of the side rim. A cavity is disposed between the wheel base and the side rim. An air seal is disposed between the wheel base and the side rim. A locking mechanism secures the side rim in position around the wheel base. The locking mechanism is configured to prevent the air seal from disengaging with the inside surface and allowing air to exit the wheel assembly between the wheel base and the side rim when the locking mechanism is properly installed. The locking mechanism is also configured to permit the air seal to disengage the inside surface and allow air to exit the wheel assembly between the wheel base and the side rim when the locking mechanism is not properly installed.