Abstract:
A bearing grease fitting for directing grease into an interior portion of a wheel hub. The bearing grease fitting is an integral piece having a protrusion with a nippled end. The grease fitting has a first portion, which seats within a wheel hub. Grease is transferred from a grease gun through the protrusion to an interior portion of a wheel, such as an axle. A bearing grease fitting assembly consists of the grease fitting together with the wheel hub.

Description:
BACKGROUND OF THE INVENTION 
     I. Field of the Invention 
     This invention relates to a bearing grease fitting that seats within a wheel hub, and more particularly, to a plastic bearing grease fitting that eliminates the need to drill through the wheel or hub in order to grease the axle or wheel bearing. 
     II. Description of the Related Art 
     The prior art uses grease fittings that are typically inserted in threaded bores within a wheel hub or the wheel itself. Grease fittings are usually manufactured of metal and are attached to a grease applicator. The grease applicator is typically a grease gun that injects grease through the grease fitting. The grease passes through the fitting and into the hub to lubricate the axle or bearings. 
     The cost to manufacture the wheel or hub is significantly increased by the need of drilling and tapping a hole to accept the grease fitting. Typically, a hole is drilled and tapped through the wheel rim or hub and the metal grease fitting is thereafter tapped into place. This is a labor-intensive manufacturing process. In addition, expensive drills and taps often break during this process. This leads to a further increase in the cost of the wheel. 
     Recently, plastic grease fittings have been used on a wheel. The plastic grease fitting eliminates the need for welding and snaps into the wheel rim or hub hole. However, one drawback of the plastic grease fitting is that the grease gun can twist off the grease fitting when applied. This twisting causes the plastic grease fitting to become “unsnapped” from the wheel thereby preventing the wheel from being properly greased. 
     The present invention contemplates a new and improved bearing grease fitting which is simple in design, effective in use, and overcomes the foregoing difficulties and others while providing better and more advantageous overall results. 
     SUMMARY OF THE INVENTION 
     A bearing grease fitting for directing grease into an interior portion of a wheel is disclosed. The bearing grease fitting has a first and a second end, a first bore with an inner periphery, a first portion that has a first outer periphery, a second portion that has a protrusion and a second outer periphery. The protrusion has a top surface and a grease delivery bore. The grease delivery bore extends from the top surface into the first bore, whereby the first portion, the second portion, the protrusion, and the grease delivery bore are integral. The bearing grease fitting directs grease to the interior portion of the wheel contained within the first bore. Typically, the interior portion of the wheel is an axle contained within the first bore of the bearing grease fitting. Preferably, the bearing grease fitting is integral and made by injection molding. 
     The inner periphery of the first bore further comprises a flow path. The flow path extends from the grease delivery bore at the inner periphery to the first end, whereby the grease flows along the flow path to the interior portion of the wheel hub. The grease delivery bore extends along a centerline that passes through the protrusion. The protrusion also extends outwardly from the second outer periphery. Preferably, the protrusion extends outwardly at an angle between 15° and 90° measured from a centerline passing through the center of the first bore to a centerline passing through the protrusion. 
     A bearing grease fitting assembly comprises the wheel hub and the bearing grease fitting described above. An alternative embodiment of the bearing grease fitting has the second outer periphery of the first portion equal to the first outer periphery of the first portion. 
     In accordance with the present invention, a new and improved bearing grease fitting is provided which seats within the wheel hub. 
     One object of the present invention is to provide a bearing grease fitting that eliminates a hole within a wheel rim or hub. 
     Another object of the present invention is to combine a grease fitting and bearing thereby eliminating the total number of parts. 
     Still other benefits and advantages of the invention will become apparent to those skilled in the art upon a reading and understanding of the following detailed specification. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention may take physical form in certain parts and arrangement of parts. A preferred embodiment of these parts will be described in detail in the specification and illustrated in the accompanying drawings, which form a part of this disclosure and herein: 
     FIG. 1 is a side sectional view of a bearing grease fitting; 
     FIG. 2 is an end view of the bearing grease fitting; 
     FIG. 3 is a sectional view of a bearing grease fitting assembly showing the bearing grease fitting seated within a wheel hub; and, 
     FIG. 4 is a partial sectional view of a wheel showing the bearing grease fitting assembly within the wheel. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, which are for purposes of illustrating a preferred embodiment of the invention only, and not for purposes of limiting the invention, FIG. 1 shows a bearing grease fitting  10 . The bearing grease fitting  10  has a first end  14  and a second end  16 . A first bore  18  extends through the first end  14  and the second end  16 . The first bore  18  has an inner periphery  20  that is constant in diameter throughout the first end  14  and the second end  16 . The first bore  18  accepts an axle  100 . 
     The bearing grease fitting  10  has a first portion  22 . The first portion  22  has a first outer periphery  24 . The first portion  22  terminates into second portion  26 . The first portion  22  has an interference fit, or an otherwise tight fit, within the hub bore  52  of the wheel hub  50 . The second portion  26  has a second outer periphery  28 . In the preferred embodiment, the second outer periphery  28  is greater than the first outer periphery  24 . However, bearing grease fitting  10  could have only one portion (i.e., second outer periphery  28  is equal to first outer periphery  24 ) and still be within the scope of this invention. The second portion  26  extends beyond the hub  50 . 
     The second portion  26  has a protrusion  30  that extends outwardly from the second outer periphery  28 . The protrusion  30  has a top surface  32  and a grease delivery bore  34 . The grease delivery bore  34  is open at the top surface  32  of protrusion  30 . The grease delivery bore  34  extends substantially through the protrusion  30  and second portion  26  to the first bore  18 . In the preferred embodiment, the protrusion  30  extends substantially outwardly from the second outer periphery  28 , so that the grease delivery bore  34  extends substantially outwardly from the second outer periphery  28 . The protrusion  30 , in its preferred embodiment, is a nippled post having a nippled end  36 . The nippled end  36  is suitable for an associated, conventional grease gun (not shown) to inject grease into the grease delivery bore  34 . The grease delivery bore  34  is preferably centered within the protrusion  30  and has a centerline C 1  through its center. The bearing grease fitting  10  has a centerline C 2  that runs through its center, i.e., through the center of the first bore  18 . The protrusion  30  is angularly oriented extending from the second portion  26 . With reference to FIG. 1, this angle is denoted as α, which is measured from the centerline C 2  of the fitting  10  to the centerline of C 1  of the grease delivery bore  34 . In the preferred embodiment, the angle α is between 15° and 90°. In its most preferred embodiment, the angle α is 60°. 
     With reference to FIGS. 1 and 3, the first inner periphery  20  of the first bore  18  has a flow path  38  which extends from the grease delivery bore exit  40 . With reference to FIGS. 2 and 3, in its preferred embodiment, the flow path  38  has a width W that is equal to the diameter D of the grease delivery bore  34 . However, the width W can vary and be greater than or less than diameter D of the grease delivery bore  34 . 
     FIG. 3 shows the bearing grease fitting assembly  12  comprising the bearing grease fitting  10  and the wheel hub  50 . In its preferred embodiment, the bearing grease fitting  10  is press fit within a hub bore  52 . The hub bore  52  has a diameter that is slightly less than the first outer periphery  24  of the bearing grease fitting  10 . 
     FIG. 4 shows a wheel  60  having the bearing grease fitting assembly  12  seated within the axle bore  62 . The wheel hub  50  has an interference or tight fit with the axle bore  62 . Preferably, the hub  50  is press-fit into the axle bore  62  and welded therein. To provide grease to the axle  100 , a grease gun (not shown) is attached to the protrusion  30  at its nippled end  36 . The grease then flows through the grease delivery bore  34  and along the flow path  38  to thereby insert the grease to the axle  100 . 
     The bearing grease fitting  10  also acts as a bearing for the axle  100 . The axle  100  rides within the first bore  18  of the bearing grease fitting  10 . Therefore, the need for a separate bearing and grease fitting are eliminated. However, a bearing could be used in place of the axle  100  and grease provided to that bearing. 
     This invention is suitable for any type of grease fitting application with a rotary shaft inside a stationary housing, a rotary material between concentric parts and all wheel hubs. The bearing grease fitting  10  is preferably an integral part. Preferably, it is made of a plastic, such as Nylatron®, and thus is inexpensive and easy to manufacture and install. The bearing grease fitting  10  is generally a cylindrical shape. 
     The above-described embodiment of the invention provides a very effective and inexpensive means of supplying grease to the wheel bearing. It also eliminates the need to drill a hole within the hub  50  and/or wheel  60  to provide grease to the axle  100 . 
     The invention has been described with reference to the preferred embodiment. Obviously, modifications and alterations will occur to others upon a reading and understanding of the specification. It is intended by applicant to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.