Abstract:
A locking hub that is useful for wheels on small vehicles. Such wheels may use a press fit or integrally cast version of the invention. The locking hub fits over a shaft. The hub has a bore for receiving the end of the shaft. An outer member is connected to and spaced from the hub. A finger is adjacent to the bore and has a protrusion that extends into the bore. The finger is resilient and movable between a first and second position. The first position has the protrusion protruding into the bore and the second position has the protrusion outside of the bore with the finger being bent radially outward. The shaft has a notch or hole that receives the finger. A locking device may selectively be placed between the outer member and the hub to prevent the finger from moving into its second position, thereby locking the hub onto the shaft.

Description:
BACKGROUND OF THE INVENTION 
     Presently, wheels for small vehicles such as garbage cans or carts are difficult to remove and maintain. Typically, wheels are installed in such a way as to be nearly permanent without the use of special tools to remove the wheel. Some wheels use a one way cantilevered catch having a protrusion that is chamfered in the direction of installation and sharp on the direction to pull the wheel off. The chamfer catches in a notch near the end of the axle. To remove such a wheel one would need a screwdriver or other object to pull the catch outward to remove the wheel. The use of cotter pins may also secure a wheel, but again requires a tool to remove the wheel. 
     Ideally, wheels for small vehicles should be easily installed and removed without tools. This is particularly important for garbage cans. Typically, aside from wheels, garbage cans are shaped so they can be nested within each other. If wheels can be easily removed, the cans could be stacked in a small space, with the wheels being stored in the innermost can. Upon delivery to its final location, the wheels could be installed on the can. Easily changeable wheels would also make maintenance simple. Modern plastic garbage cans are usually tough enough to take many years of abuse. However, protruding wheels are vulnerable to damage or wear as the moving part of the can that supports the weight of the can and its contents. If a wheel becomes damaged throughout the life of a garbage can, the entire can does not have to be replaced. A replacement wheel or wheels, with simple instructions, could be shipped and installed on the garbage can, possibly even by an end user of the garbage can. 
     SUMMARY OF THE INVENTION 
     The present invention is a locking hub that may be used for a wheel. The wheel may have a press fit locking hub, or the hub may be integrally cast into the wheel. The locking hub has a hub for fitting over an end of a shaft. The hub has a bore with an inner diameter for receiving a shaft and an outer surface. An outer member may be connected to and spaced from said hub. A finger is adjacent to the bore and has an inner surface and an outer surface. The finger includes a protrusion that has a raised surface relative to the inner surface of the finger. The finger is adapted for extending into the bore for a predetermined distance. The finger is resilient and movable between a first and second position. The first position has the protrusion protruding inwardly into the bore. The second position has the protrusion located outwardly of the bore. In the second position the outer surface is located radially outward relative to the first position. 
     A locking device may be selectively used to restrain the movement of the finger from the first position into the second position. 
     In one aspect of the invention, the locking device may be insertable between the finger and an outer member that may be a cylinder spaced from the hub. In this case, the finger is blocked by moving from its first position to its second position due to the presence of the locking device between the finger and cylinder. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an exploded assembly of the hub, locking cap, and axle shaft; 
         FIG. 2  is an inboard end view of the hub shown in  FIG. 1 ; 
         FIG. 3  is a sectional view of the hub taken about the line  3 - 3  in  FIG. 2 ; 
         FIG. 4  is the section shown in  FIG. 3  with the locking cap partially inserted into the hub; 
         FIG. 4A  is an enlarged view from area  4 A in  FIG. 3 ; 
         FIG. 5  is the section shown in  FIG. 3  with the locking cap fully inserted into the hub; 
         FIG. 6  is sectional view taken about the line  6 - 6  in  FIG. 5 ; 
         FIG. 7  is a perspective view of the hub and locking cap shown in  FIG. 1  more clearly showing the tabs on the locking cap; 
         FIG. 8  is a perspective view of an exploded assembly of the hub integrated into a wheel, a locking cap, and axle shaft; 
         FIG. 9  is a sectional view taken about the line  9 - 9  in  FIG. 8 ; 
         FIG. 10  is a perspective view of a wheel with a hub as shown in  FIG. 1  press fit into the wheel; and 
         FIG. 11  is a sectional view taken about line  11 - 11  in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF INVENTION 
     The locking hub  10  is shown in an exploded perspective view in  FIG. 1 . The locking hub  10  is particularly useful for securing a wheel to an axle shaft  11 . The locking hub  10  has a hub  12  located within an outer cylinder  14 . The hub  12 , shown in sectional  FIGS. 3-5 , has a bore  16  with an inner diameter  18 . The bore  16  terminates at an end wall  19 . The hub  12  has an outer surface  20  that is coaxial with said inner diameter  18  of said bore  16 . A finger  24  is cantilievered adjacent to the bore  16 . The finger  24  has a connected end  23  and a free end  21 . The finger  24  has a curved inner surface  26  that faces the bore  16  and an outer surface  28 . The inner and outer surfaces  26 ,  28  are curved with the same radius as the inner diameter and outer surface  18 ,  20  of the hub  12  respectively. The connected end  23  of the finger  24  farther from the end wall  19  is integrally molded into the hub  12  to form a continuous connection at the connected end  23  of the finger  24 . A protrusion  29  extends from the inner surface  26  of the finger  24  near its free end  21 . The corners of the protrusion  29  have chamfers  30 .  FIG. 4  shows the finger  24  in a first position. In this first position, the protrusion  29  extends inwardly into the bore  16 , and the inner surface  26  of the finger  24  is at the same level and curvature as the rest of the inner diameter  18  of the bore  16 . In the first position, the outer surface  28  of the finger  24  is at the same level as the outer surface  20  of the hub or, in other words, the finger  24  is aligned with the hub  12 . The protrusion  29  has chamfers  30  on its inboard and outboard sides. The inboard side referring to the left in  FIGS. 3-5 , and the outboard side referring to the right side in the same FIGS. The term inboard more generally means toward the inner part of the shaft  11 , and outboard means toward the end of the shaft  11 . Because the end of the shaft is shown toward the right in  FIGS. 3-5 , outboard is right and on the opposite end of the shaft  11 , that is not shown, outboard would be left. A second position of the finger is shown in  FIG. 3 . In this position, the protrusion  29  is moved out of the bore  16  and the outer surface  28  is moved radially outward from the first position. As can be seen in  FIG. 3 , the outer surface  28  of the finger  24  is above the outer surface  20  of the hub  12 . In other words, the finger  24  is not aligned with the hub  12  in its second position. 
     The locking hub  10  has an outer cylinder  14  that is concentric with the hub  12 . The outer cylinder  14  has an inner surface  34  and an outer surface  36 . The outer cylinder is supported on the outside of the hub  10  by a series of spokes  35 . The spokes  35  run longitudinally in the annular space  40  between the outer cylinder  14  and outer surface  20  of the hub  12 . The spokes  35  are spaced so that movement of the finger  24  into its second position is not restricted by the spokes  35 . As can be seen in  FIG. 3 , the outer surface  28  of the finger  24  nearly touches the inner surface  34  of the outer cylinder  14 . The outer surface  36  of the outer cylinder  14  has a series of splines  42  extending from it. It is contemplated that the inner surface  34  of the cylinder can be an integral part of a wheel as shown in  FIG. 8 . In the embodiment shown in  FIG. 8 , the hub  10  is an integral feature of the wheel  46  and is typically injection molded at the same time as the rest of the wheel  46  in one process. The functioning of the hub  10  in this embodiment is exactly the same as that shown in the  FIGS. 1-7  and  FIG. 10 , and it is the wheel  46  itself that defines the outer surface  36 . 
     An insertable cap  50  is shown in  FIG. 7  and is adapted for mating with the hub  10 . The cap  50  has an insertable portion  52  that has a series of tabs  54  extending from the cap as shown in  FIG. 7 . Adjacent tabs  54  define slots  56  between them. The tabs  54  are adapted for being inserted in the annular space  40  between the outer surface  20  of the hub  12  and the inner surface  34  of the outer cylinder  14 .  FIGS. 4 and 5  show the cap  50  being inserted into the space  40 . Each tab has a ridge  57  near its respective end. The ridges  57  on the tabs  54  protrude inwardly. The tabs  54  are resiliently cantilevered onto a base  60 . A finger tab  54 ′ is adapted for insertion between said finger  24  and said inner surface  34 . 
       FIG. 3  shows a section of the hub  10  without an integrally cast wheel circumscribing the hub  12 . The tabs  54  are shown extending partially into the annular space  40 . An outboard collar  64  stands raised above the outer surface  20  of the hub  12 . The outboard collar  64  extends all around the hub  12  with the exception of the portion of the hub  12  where the finger  24  is located. The tabs  54  are shown inserted just beyond the outboard collar  64  so that the ridges  57  are beyond the outboard collar  64 . The tabs  54  being resilient and cantileivered are biased inwardly toward the center of the hub  12  so that when the tabs  54  are inserted into the annular space  40 , the ridges  57  will contact the outer surface  20  of the hub  12 . To move the ridges  57  past the outboard collar  64  requires enough force to bend the tabs  54  as the ridges  57  pass over the collar  64 . Thus, when the tabs  54  are partially inserted into the annular space, some force will be required to remove the cap  50  from the hub  10 . The outboard collar  64  is positioned so when the ridges  57  are inboard of the collar  64  and contacting said collar  64 , tab  54 ′ will not be positioned between the outer surface  28  of the finger  24  and the inner surface  34 . 
       FIG. 5  shows a section of the hub  10  with the cap  50  fully inserted. With the cap  50  in this position, the ridges  57  are located inboard of an inboard collar  68 . The inboard collar  68  extends all around the hub  12  with the exception of the portion of the hub where the finger  24  is located. The inboard collar  68  is positioned so that when the ridges  57  are contacting the inboard side of collar  68 , the base  60  of the cap rests on the end of the hub as shown in  FIG. 5 . Similar to the outboard collar  64 , some force is required to move the tabs  54  over the inboard collar  68 . As such, some force is required to dislodge the cap  50  from the position shown in  FIG. 5 . Throughout the process of inserting the tabs  54  of the cap  50 , no rotation of the cap  50  occurs, only axial movement. 
     When a user of the hub  10  wishes to install a wheel  46  on an axle shaft  11  he will first insert the axle  11  into the bore.  FIG. 8  shows the integral hub that is cast into the wheel  46 , and  FIG. 10  shows a wheel  70  with the hub  10  press fit into a wheel  70 . The shaft  11  has a chamfer  76  on its end and a notch  78  near its end. Although the notch  78 , shown in  FIGS. 1 ,  3 - 5 ,  8  and  10 , is a 360 degree notch, a hole or partial notch could serve the same function. When the chamfer  76  passes by the protrusion  29  on the finger  24 , the shaft  11  will push the finger  24  into its second position shown in  FIG. 3 . Once the shaft  11  is fully inserted into the bore  16  with the shaft contacting the end wall  19 , the finger  24  will return to its first position, and the protrusion will extend into the bore  16  and be captured within the notch  78 . If the shaft  11  is pulled out of the bore  16 , it will move the finger  24  back into its second position before the shaft can be removed from the bore  16 . To prevent the shaft  11  from leaving the bore  16 , the finger can be restrained from moving into its second position. To prevent the wheel  46 ,  70  from coming off the shaft  11 , the cap  50  is inserted into the space  40  between the hub  12 , and the inner surface  34 . The tab  54 ′ adjacent to the finger  24  occupies the space  40  so that the finger  24  cannot move radially outward and therefore, the protrusion  29  remains extending into the notch  78  within the bore  16 . The user will be certain the wheel  46 ,  70  is locked onto the shaft  11  when the base  60  of the cap rests on the hub  12 , as shown in  FIG. 5 . If it is desired to remove the wheel at a later time, the cap  50  may be pulled partially out into the position shown in  FIG. 4 , and the wheel  46 ,  70  may be removed. Due to the chamfers  30  on the protrusion  29 , as the wheel is pulled off of the shaft  11 , the sharp corner  80  in the notch  78  will not catch the protrusion  29  in a way that would prohibit the finger  24  from moving into its second position to facilitate removal of the wheel. The cap  50  will be retained within the hub  10  in the wheel  46 ,  70  because the ridges  57  on the tabs  54  will catch on the outboard collar  64 . Because the cap  50  can remain captured within the hub  10 , wheels  46 ,  70  may be shipped with the cap  50  partially installed in the position of  FIG. 4 . It is also possible to ship hubs  10  as shown in  FIG. 1  that may be later press fit into a wheel  70  with the cap  50  partially installed. 
     The invention is not limited to the details above, but may be modified within the scope of the following claims.