Abstract:
A bearing and circular raceway lubrication apparatus includes congruent and nesting male and female, polymeric material plates wherein the male plate includes a counterbore opening for receipt of a rod with a hollow shaft through which lubricant is directed into the region between nested plates when a bearing raceway is compressed between the plates. The female plate includes an integrally molded hub with a threaded throughbore for receipt of the hollow shaft.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an apparatus which is used to encapsulate and lubricate bearings, for example, ball bearings mounted in a bearing raceway. 
     Mechanics and other repairmen who have the responsibility for maintaining vehicles and other apparatus of the type having a shaft or axle mounted with bearings, often find it necessary to lubricate the bearings. Lubrication is typically effected by removal and cleaning the raceway containing the bearings and/or injecting or otherwise forcing a lubricating material into the raceway and around the bearings. Applicant&#39;s assignee has in the past manufactured and sold apparatus to effect such lubrication. 
     Prior art apparatus is comprised of first, second congruent, molded polymeric, conically shaped plates which are nested or overlie one another. The first plate includes a threaded aluminum rod or shaft extending from the apex of the plate. The rod is threadable into an aluminum fitting which is attached to the apex of the second plate. In use, a raceway with bearings is positioned between the plates, and the plates are rotated with respect to each other to narrow the space between the plates and thereby encapsulate the raceway. The aluminum shaft projected from the first plate contains a hollow passageway which is connected to the region or space between the plates where the encapsulated raceway is located. Lubricating material is injected through that passageway into the region between the plates and envelopes the raceway and bearings forcing old lubricating material and dirt from and encapsulating the raceway with new lubricating material. Any excess lubricating material is ejected outwardly between the peripheral edges of the plates. 
     The described apparatus works well. However, the cost of manufacture is significant. Moreover, the mechanism for attaching the aluminum shaft to the one plate and for attaching the threaded aluminum hub to the other plate is not fail safe. For example, the polymeric parts may separate from the aluminum parts, thereby rendering the apparatus ineffective. Thus there is a recognized need for an improved assembly and construction of such apparatus. 
     SUMMARY OF THE INVENTION 
     In a principal aspect, the present invention comprises a set of male and female conical plates which are substantially the same size and shape. The male plate includes a central counterbore integrally molded therewith at the apex or centerline of the plate. The counterbore is adapted to receive a threaded hollow shaft or rod with a valve fitting at the outer or distal end of the shaft. The shaft is threaded into the counterbore. The female plate includes an integrally molded hub with an internally threaded throughbore adapted to receive the aluminum rod or shaft projecting from the male plate. The hub includes external flutes or ribs in a pattern that facilitate manual manipulation of the female plate by rotation to appropriately encapsulate and compress a bearing assembly or raceway between the plates. 
     Thus it is an object of the invention to provide an improved apparatus for effecting lubrication of a wheel bearing assembly of the type which includes bearings in a cage or raceway. 
     A further object of the invention is to provide an improved apparatus for lubrication of a wheel bearing assembly wherein the apparatus is comprised of fewer parts, is easily assembled wherein the parts comprising the apparatus are fabricated in a manner which ensures the reliability of the apparatus and wherein the apparatus is less expensive to manufacture and assemble. 
     These and other objects, advantages and features of the invention will be set forth in the detailed description which follows. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     In the detailed description which follows, reference will be made to the drawing comprised of the following figures: 
     FIG. 1 is an exploded, isometric view of a typical prior art bearing lubrication apparatus; 
     FIG. 2 is an exploded, isometric view of the bearing lubrication apparatus of the invention; 
     FIG. 3 is a plan view of the male plate associated with the apparatus of the invention; 
     FIG. 4 is a cross sectional view of the plate of FIG. 3 taken along the line  4 — 4 ; 
     FIG. 5 is an elevation or plan view of the shaft associated with the male plate of FIGS. 3 and 4; 
     FIG. 6 is a top plan view of the female plate; and 
     FIG. 7 is a cross sectional view taken along line  7 — 7  of FIG. 6 of the female plate. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 depicts a known prior art construction for apparatus to lubricate bearings in a bearing assembly or raceway. The prior art apparatus includes five separate parts, two of which are molded plastic parts. The three remaining parts are machined, typically, from aluminum. Thus, the prior art device includes a first, molded plastic, male plate  10  and a second, molded plastic, female plate  12 . The plates  10  and  12  are conical and substantially identical in configuration. A hollow shaft or rod  14  with a grease valve fitting  16  at one end and an axial throughbore  18  connected to a transverse outlet or passage  20  is attached to the first, male plate  10 . Cooperative with the shaft or rod  14  is a cap  22 . Cap  22  includes a rim  24  that is crimped to the side of a passage  26  which extends axially from the apex of the frustoconical plate  10 . The rod or shaft  14  is then threadably inserted into the cap  22  so that the combination of plate  10 , rod  14  and cap  22  comprise the male component of the lubrication device. 
     The female or second frustoconical plate  12  includes a through passage  28  into which a machined aluminum fitting  30  is inserted and is attached thereto by crimping of an annular rim or rib  32  of the fitting  30  over the edge of passage  28 . The fitting  30  is knurled on its outside surface and has a threaded interior throughbore  34  for threadable receipt of the rod  14 . 
     In operation, a bearing raceway, such as a circular bearing race  36 , is positioned over rod  14  on plate  10 . The second plate  12 , and more particularly the collar  30 , is then threaded onto the rod  14  and the plate  12  is tightened against the bearing race  36 . The transverse passage  20  exits in the space between the plates  10  and  12 . A grease gun or other source of lubrication is attached to the fitting  16  and lubricating material is forced through the throughbore  18  and the passageway  20  into the region between the plates  10  and  12 . The lubricating material then forces itself outwardly, radially from the center of the shaft of rod  14  and effects removal of prior lubricating materials from the race  36 . Lubricating material then fills the spaces within the race. The plates  10  and  12  may then be separated so that the race can be used in a vehicle or the like. 
     The remaining figures illustrate the improved construction of the present invention wherein a number of component parts have been eliminated, and further, the price, efficiency, cost of construction or manufacture and reliability are all improved relative to the prior art construction. Specifically, a frustoconical, molded plastic, first, male plate  40  includes an integrally molded counterbore passage  42  molded in a central axial depending projection  44  centered on an axis  46 . Bore or passage  42  is threaded to receive a threaded rod or shaft  48 . The rod or shaft  48  has outer threads  50  and an internal axial through passage  52  connected to a transverse discharge passage  54 . The rod  48  is threadably inserted into the counterbore  42  and tightly retained therein by the interaction of the threads of the rod  48 , which is typically a metal rod, for example aluminum, and the molded material comprising the plate  40 . Plate  40  is typically made from a Delrin material. A characteristic of the threaded interaction between the aluminum threads  50  and the threads of the counterbore  42  is tight retention of the rod  48 . 
     The device further includes a grease valve fitting  56  attached to the the free outer end of the rod  48 . Valve fitting  56  is compatible with a grease gun or other source of lubrication which may be fitted onto the valve  56  to provide lubricating material through the passage  52  and passage  54 . 
     As a separate component, the combination includes a second, female, frustoconical molded polymeric or plastic material plate  60 . The plate  60 , like the plate  40 , includes an inner conical surface  62  and an outer surface  64 . The inner surface  62  is engageable or opposed to outer conical surface  41  of plate  40 . The circumference and cross sectional dimensions of the plates  40  and  60  are substantially the same so that the plates  40 ,  60  are generally compatible and congruent. 
     The second plate  60  further includes an axial hub  66  which is integrally molded with the plate  60  and which extends or projects outwardly in the direction of the centerline of the apex of the frustoconical member or plate  60 . The hub  66  includes a series of at least four parallel, axial flutes  68  equally spaced about the periphery of the hub. The flutes facilitate gripping and rotation of the plate  60  on the shaft  48 . The hub  66  is internally threaded with an internal through passage  70  into which the rod or shaft  48  is threadable received. Thus the plates  60  and  40  may be rotated relative to one another to compress an item (bearing raceway) retained therebetween. 
     With the improved bearing lubrication apparatus of the invention, fewer component parts are utilized thus reducing the cost of assembly and further reducing the number of machining and other similar operations that must be performed in the manufacture of the product. Further the product is deemed to be more rugged or rigid since it is unitary. Other variations of the construction may be possible. Thus the invention is to be limited only by the following claim and equivalents thereof.