Abstract:
A stud installation tool includes a thrust bearing mounted within an annular housing so that the bearing may be brought in contact with a wheel hub plate and fitted around a stud which is to be drawn into the plate. Lug nuts for the stud may be tightened against the tool thereby eliminating the necessity for special sizes and styles of stud nuts.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     In a principal aspect, the present invention relates to a tool which is useful for the installation of studs, particularly the studs that are located on the hub of a motor vehicle for attachment of the wheel rim to the hub.  
         [0002]     Typically, in motor vehicles threaded studs extend from a plate of the wheel hub which is attached to the axle of the vehicle. The threaded studs project outwardly from the plate and are designed to cooperate with lug nuts that fasten the wheel rim to the plate. Typically, the studs comprise a headed fastener or bolt with a knurled shaft section adjacent the head. The outer end of the shaft is threaded to enable attachment of a lug nut. The knurled section of the stud shaft is forced through an opening in the plate of the wheel hub to thereby retain the stud.  
         [0003]     Studs may break during usage. Also, the threads on the shaft of the stud may become stripped, or other reasons may develop requiring removal and replacement of one or more studs. Replacement may be undertaken by using a drift-punch or other driver to remove the stud from the plate in which it is mounted. Thereafter, a new stud is inserted through the stud opening from the backside of the plate and driven into position. Numerous devices have been proposed for installation of such studs, including those depicted in the following patents:  
                                   Pat. No.   Title                   4,741,229   STUD INSTALLER       4,872,254   WHEEL STUD INSTALLER AND METHOD       5,209,623   WHEEL STUD INSTALLATION APPARATUS       5,839,180   STUD INSTALLER FOR WHEEL STUDS       6,505,390   METHOD FOR REPLACING WHEEL STUDS       6,618,920   WHEEL STUD INSTALLATION TOOL       6,823,574   TOOL FOR INSTALLING WHEEL STUDS                  
 
 Additionally, various stud installation tools have been introduced to the marketplace. 
 
         [0004]     While such tools and methods disclosed in the known prior art are quite useful, and capable of performing the desired function, various challenges arise for a mechanic responsible for replacing the studs. For example, studs are provided with various shaft diameters and thread configurations. Consequently, using a tool such as depicted, for example in U.S. Pat. No. 5,209,263, may require special threaded nuts for the replacement of each differently sized or differently threaded stud.  
         [0005]     Another challenge that is presented with respect to such stud removal and replacement tools is represented by the certain patents cited above. That is, that forces required to place a stud in a wheel plate are often significant. Consequently providing a device or tool which will enable the easy replacement and insertion of a stud through an opening in a plate is often difficult.  
         [0006]     Thus, there has developed a need to provide improved methods for insertion of wheel studs in the hub wheel plate of a motor vehicle. Ease of stud replacement in other environments is also desirable. Another desired feature of a stud replacement tool is the ability to use the tool in confined or restricted spaces. In view of these desires and issues, the present tool was developed.  
       SUMMARY OF THE INVENTION  
       [0007]     Briefly, the present invention is a stud installation tool generally comprised of two, basic component parts. The two, tool parts are generally symmetrical about a longitudinal axis. The first component part comprises an annular thrust bearing, which is inserted into a counterbore at one end of the second component part, namely an annular configured body or housing. The second component part includes an axial throughbore extension of the counterbore. Thus, a stud may be fitted longitudinally through the bore, the thrust-bearing, and the housing in which the bearing is seated. The thrust bearing projects axially slightly beyond the end surface of the housing so that the thrust bearing may impinge against the hub plate in which the stud is to be positioned. The opposite side of the housing includes a generally frustoconical, axial counterbore. The frustoconical counterbore enables the housing to receive a lug nut having a frustoconical axial end or projection which is typically utilized to draw down or tighten a wheel rim on a wheel hub mounting plate.  
         [0008]     As a consequence, a tool of the invention has a number of important advantages. First, studs with various diameter shafts may be easily replaced using the tool and matching lug nuts. The throughbore in the tool is, thus, capable of receipt of stud shafts having various diameters. Second, because of the configuration of the body counterbore, which receives the lug nut, lug nuts with a variety of diameters and configuration may easily co-act or cooperate with the tool. The frustoconical configuration of the axial counterbore in one side of the body or housing enables such cooperation.  
         [0009]     As a further feature of the invention, the thrust bearing may include an interior dust cover or annular ring which fits against the inside surface of the thrust bearing to protect the bearings from dust, grime and dirt.  
         [0010]     As another feature of the invention, the body or housing of the tool may include one or more passages which enable insertion of a probe from one end of the body to drive the bearing from the counterbore at the opposite end of the housing or body. Consequently, if a bearing fails, it may be easily replaced.  
         [0011]     An important feature of the invention is the fact that the thrust bearing will impinge, or is designed to impinge, against the stud mounting plate when the tool is properly used. Consequently, when a lug nut is placed upon a stud and drawn or threaded thereon to thereby draw the stud into the plate, the thrust bearing ensures that the body or housing of the tool, which is frictionally engaged by a lug nut, can be easily rotated so as to direct a maximum amount of pulling force on the stud which is being drawn into engagement with through a passage in the mounting plate.  
         [0012]     Thus, it is an object of the invention to provide an inexpensive, rugged, and easily useable stud installation tool.  
         [0013]     Another object of the invention is to provide a stud installation tool which uses a bearing with an optional dust ring or cover and which is sized to enable the tool to be utilized in combination with studs of multiple diameter and thread configurations.  
         [0014]     Another object of the invention is to provide a stud installation tool which does not require a special threaded driving nut associated therewith but which may utilize existing lug nuts associated with the vehicle studs for mounting a wheel rim on the vehicle. Consequently, a minimum number of parts are utilized in the tool of the invention.  
         [0015]     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  
       [0016]     In the detailed description which follows, reference will be made to the drawing comprised of the following figures:  
         [0017]      FIG. 1  is an exploded side elevation view of the component parts of the tool;  
         [0018]      FIG. 2  is a plan elevation of a body or housing depicted in  FIG. 1 ;  
         [0019]      FIG. 3  is a cross-sectional view of the housing or body of  FIG. 2 , taken along the line  3 - 3 ;  
         [0020]      FIG. 4  is a plan view of a thrust bearing which is incorporated as a component part of the tool and which is illustrated in  FIG. 1 ;  
         [0021]      FIG. 5  is a cross-sectional view of the bearing of  FIG. 4  taken along the line  5 - 5 ;  
         [0022]      FIG. 6  is a plan view of a dust shield, or dust cover, which is depicted in  FIG. 1  and may be incorporated with the tool of the invention;  
         [0023]      FIG. 7  is a cross-sectional view of the dust shield, or dust cover, of  FIG. 6  taken along the line  7 - 7 ;  
         [0024]      FIG. 8  is an exploded sectional view of the tool of the invention depicted in combination with a stud and wheel hub mounting plate to demonstrate the manner of use and method of the invention;  
         [0025]      FIG. 9  is an exploded isometric view of the component parts illustrated in  FIG. 8 , further illustrating the method of the invention; and  
         [0026]      FIG. 10  is an isometric view illustrating in greater detail the method of the invention utilizing the tool.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0027]     The tool of the invention is comprised generally of two basic component parts and an optional part. The two basic parts comprise a body or housing  10  and a thrust bearing  12 . An optional, but preferred, dust cover  14  is provided for cooperation with the thrust bearing  12  to protect the bearing  14  from dirt and contamination during use. The housing  10 , thrust bearing  12 , and dust shield or cover  14  are generally symmetrical about a longitudinal axis  16 . As shown in  FIGS. 2 and 3 , the housing or body  10  includes a first counterbore  18  which is generally cylindrical and extends along the axis  16  from one end of housing  10 . First counterbore  18  includes a cylindrical side wall  20  and an annular bottom or base wall  22 . The first counterbore  18  is symmetrical with and connected via a cylindrical passage to a generally frustoconical shaped counterbore  24  extending from the second or opposite end  26  of the body  10 . A shaped throughbore thus extends entirely through the body  10  along the axis  16  between a second side or end  26  to a first end or side  25 . The frustoconical counterbore  24  includes a maximum radial dimension generally at the outer surface of the second side  26  and a reduced diameter dimension within the interior of the counterbore generally equal to the diameter of passage  30 . The diameters of the frustoconical section  24  at its narrowest point and of passage  27  are chosen so that studs of multiple sizes or diameters of the stud shaft may fit though the counterbores and passage through the body  10 . The included angle  31  of the frustoconical counterbore surface  24  is generally about 60°+10°. The diameter of cylindrical section  30  and of the through passage of the thrust bearing  12  are chosen to enable a maximum number of various stud shaft sizes to fit through the body  10  as well as the thrust bearing  12  positioned within the body  10  as, for example, depicted in  FIG. 8 .  
         [0028]     The thrust bearing  12  depicted in  FIGS. 4 and 5  is a generally annular member comprised of first and second annular bearing sections or parts  32  and  34  separated by and cooperative with a series of ball bearings  36  in channels such as channels  38  and  40 . A sleeve  42  holds the bearing members  32  and  34  in a cooperative position. The thrust bearing  12  includes an outer face or surface  50  and an inner face or surface  52 . The thrust bearing  12  is inserted to the counterbore  18  and extends axially outwardly from the first surface  25 , again, as depicted in  FIG. 8  for a distance, A. As a consequence, as explained in detail hereinafter, the thrust bearing  12  may be fitted against the surface of a wheel hub plate  60  to separate the body  10  slightly from the surface of the plate  60 .  
         [0029]     In the preferred embodiment, a dust cover  14  or dust shield  14  in the form of an annular ring, as depicted in  FIGS. 6 and 7 , is inserted against the inside surface of the thrust bearing  12 . This dust cover  14  protects the bearings within the thrust bearing  12  (e.g., ball bearings) from dust, dirt and grime. The component parts, namely the body  10 , the thrust bearing  12  and dust cover  14  are assembled as depicted in  FIG. 8 . The component parts are coaxial and symmetrical about the axis  16 . The body  10  may rotate relative to the bearing  12  as a result of the imposition of a turning force on the body  10 . The body  10  and, more particularly, the counterbore  24  is designed to be cooperative with a standard lug nut, such as a lug nut  70  of the type including a frustoconical surface  72  and a polygonal nut drive section  74  symmetrical about axis  16 . An internal, axial through passage  76  of nut  70  is threaded and designed to be cooperative with a shaft  78  of a stud  80 , which includes a head  82  and knurled section  84 . It is noted that most lug nuts  70  have a frustoconical configuration such as that depicted in  FIG. 8  and thus the frustoconical section  24  of the body  10  is generally compatible with multiple sizes of lug nuts  70 . Also, the lug nut  70  designed for use with stud  80  may be used, thus avoiding the necessity of special lug nuts for use with the tool.  
         [0030]     The method of use of the tool is depicted in  FIGS. 8, 9  and  10 . Specifically a stud  82  is inserted through a passage  90  in the plate  60 . The housing or body  10  is fitted over the opening  90  so that the thrust bearing  12  will be guided against the outer surface of the plate  60 . An appropriate standard lug nut  70  is then threaded on the shaft  78  with the frustoconical portion thereof against the surface of the frustoconical section  24  as shown in  FIG. 8 . Lug nut  70  is then tightened to pull the stud  82  through the opening  90  to engage the knurled sections thereof with the sides of the opening  90  to retain the stud  82  in position within the plate  60 .  
         [0031]     It is noted that there are axially aligned through passages  96  and  98  radially positioned on opposite sides of the axis  16  within the body  10 . Those passages  96  and  98  are aligned with the outer edges of the thrust bearing  12 . Thus, if the thrust bearing  12  should fail, a tool may be inserted through the passages  96  and  98  to effect removal of the thrust bearing  12  and permit replacement thereof.  
         [0032]     With the tool of the invention, various sizes of studs  80  may be directed through the opening in the body  10  and thrust bearing  12  for engagement with appropriately sized lug nuts  70 . Lug nuts of multiple sizes are therefore can be used with the frustoconical opening or counterbore  24  of the body  10 . Thus, lug nuts specifically associated with the lugs or studs, such as stud  80 , may be used during the installation process associated with use of the tool. As a result, the utilization of specially sized and specially threaded nuts or lug nuts is not required with the tool of the invention. The lug nuts associated with the particular wheel assembly may be utilized to facilitate replacement of the studs.  
         [0033]     It is possible to alter the design and configuration of the various component parts while not departing from the spirit and scope of the invention. The particular type of thrust bearing may be varied. For example, ball bearings or roller bearings or other type of bearings may be used. The particular configuration of the various counterbores may also be altered. The utilization of a dust cover and the shape and configuration and material used to make the dust cover or shield may all be varied without departing from the spirit and scope of the invention. The invention is therefore to be limited only by the following claims and equivalents thereof.