Background of the Invention
1. Field of the Invention
This invention relates in general to certain new and useful improvements in wheel nut assemblies and means and method for mounting a non-ferrous wheel to a hub of a vehicle, and more particularly, to a wheel nut assembly and a means and method for mounting a non-ferrous wheel to a hub which utilizes a nut with a skirt and an insert extending between an opening in the wheel and surrounding the body of the nut and the skirt thereon.
2. Brief Description of the Prior Art
In recent years, automobile manufacturers have resorted to the production of non-ferrous wheels for motor vehicles and particularly, wheels made of aluminum and magnesium. In addition, wheels which are made of non-ferrous materials are frequently offered in the automotive aftermarket or so-called "secondary market" for purposes of customizing a vehicle. As a result of their light weight, non-ferrous wheels have been used frequently in racing vehicles and have thereby become popularized. Accordingly, many automotive enthusiasts will therefore substitute these non-ferrous wheels for the conventionally provided steel vehicle wheel.
Several problems have been encountered when attempting to mount a non-ferrous wheel to the hub of a vehicle. Generally, the hub is formed of steel and the lug nuts used to secure the wheel to the hub are also formed of steel. When using the conventional lug nut, portions of the wheel surrounding the bolt holes, which receive the bolt stem or so-called "stud" extending from the hub, are effectively compressed between the lug nut and the hub. Inasmuch as the nut and the hub are formed of a much harder material than the non-ferrous wheel, they effectively bend and crush portions of the softer non-ferrous metal wheel. Accordingly, the user of the non-ferrous wheel had to exercise special care when tightening the lug nut onto the bolt stem extending from the hub in order to preclude damage to the wheel. Moreover, this concern causes the user to exercise caution and the user often fails to tighten the lug nuts with the requisite amount of torque to obtain a safe mounting of the wheel.
In addition to the above, in order to tighten the lug nut against the wheel with the requisite amount of force, the aluminum wheel had to have sufficient thickness in the region of the bolt receiving holes in order to accommodate the compressive force which is imposed on the wheel. If there was not sufficient thickness of metal forming the wheel and surrounding the hole, then the wheel could be easily crushed or bent. However, generally all hub studs are of a standard length. Moreover, that length is established for the mounting of steel wheel onto the hub using steel lug nuts. As a result, when there is an increased thickness in the wheel in the region surrounding the holes which receive the hub stems, there is less threaded length of the stud available for engagement by the lug nut. As a simple example, where the conventional stud is 3/4 inches long, if the wheel was made with a thickness of 1/2 inch, in the region of the holes receiving the studs, then there would only be about 1/4 inch or less remaining for securement of the lug nut.
This problem of insufficient tightening length of the wheel stud available for a lug nut has created several problems. First of all, there is not sufficient gripping length of the stud available in order to obtain effective tightening action of the wheel lug nut with the required amount of force. Moreover, due to the fact that the lug nut is not securely tightened onto the hub stud, there is a tendency for the wheel nut to vibrate and become loosened from its position on the threaded stud. This condition creates the obvious danger of the wheel becoming loosened from the wheel hub during movement of the vehicle.
Objects of the Invention
It is, therefore, one of the primary objects of the present invention to provide a lug nut assembly which enables the mounting of a non-ferrous wheel to the hub of a vehicle and which utilizes a skirted lug nut and an insert adapted for surrounding disposition about the skirted nut.
It is another object of the present invention to provide a lug nut assembly of the type stated which permits tightening of the wheel against the hub without any substantial risk of damaging the wheel.
It is a further object of the present invention to provide a lug nut assembly which enables the tightening of the wheel onto the hub of a vehicle with the desired amount of force in order to obtain a positive and secure mounting of a non-ferrous wheel onto the vehicle hub.
It is an additional object of the present invention to provide a lug nut assembly of the type stated which can be used with a wide variety of vehicles produced by various manufacturers thereof.
It is another salient object of the present invention to provide a lug nut assembly of the type stated which is highly effective in use and which can be manufactured at a relatively low cost.
With the above and other objects in view, my invention resides in the novel features of form, construction, arrangement and combination of parts presently described and pointed out in the claims.
Brief Summary of the Invention
A wheel nut assembly for mounting of a non-ferrous wheel to a wheel hub and which hub is typically formed of a steel material. The assembly comprises a lug nut having a body section with a plurality of peripheraly extending tool engaging walls. This body section also has a central bore extending therethrough. The tool engaging walls are preferably flat surfaces, such as hexagonally arranged surfaces adapted to be received by the socket of a wrench.
A skirt is located on the nut and extends axially with the bore outwardly from the tool engaging walls. The skirt is preferably integrally formed with the body of the nut itself. Moreover, the skirt also has a cental bore in alignment with the central bore of the body and is sized to receive a stud extending outwardly from the hub of the vehicle.
The wheel nut assembly of the present invention also comprises an insert formed of a ferrous material and which is adapted to extend around a portion of the skirt. The insert is also provided with a central opening to receive the skirt. The ferrous insert further has an outer wall which is adapted to engage the opening in the wheel. In a more preferred embodiment, the ferrous insert also engages a portion of the body of the lug nut as well as the skirt of the lug nut. The insert is centrally opened and has an interior shape in the central opening to conform to and snuggly engage both the skirt and a portion of the body of the lug nut.
In accordance with the above identified construction, the insert surrounds the lug nut and since it does not have any relatively sharp corners the forces imposed on the insert by the lug nut are distributed throughout the surface of the insert. As a result, the lug nut can be tightened with a substantial amount of force against the insert which, in turn, bears against the softer aluminimum wheel. This construction utilizing a skirt on the lug nut and which is surrounded by the insert enables the lug nut to engage a substantial portion of the length of the lug nut. This construction thereby eliminates the tendency of the lug nut to vibrationally unwind on the shank of the stud extending from the wheel hub.
This invention possesses many other advantages and has other purposes which may be made more clearly apparent from a consideration of the forms in which it may be embodied. One of the preferred forms in the invention is more fully described in the following detailed description of the invention. However, it is understood that such detailed description is not to be taken in a limiting sense and is only illustrative of one of the preferred embodiments of the present invention.
Brief Description of the Drawings
Having thus described the invention in general terms, reference will now be made to the accompanying drawings (two sheets) in which:
FIG. 1 is a side elevational view, partially broken away and in section, and showing a prior art mounting arrangement utilizing a steel nut bearing against an aluminum wheel;
FIG. 2 is a side elevational view, partially broken away and in section, showing a lug nut assembly for mounting an aluminum wheel to a vehicle hub in accordance with the present invention;
FIG. 3 is a vertical sectional view taken along line 3--3 of FIG. 2;
FIG. 4 is a perspective view showing a portion of an insert used in the lug nut assembly of the present invention;
FIG. 5 is a horizontal sectional view taken along line 4--4 of FIG. 2; and
FIG. 6 is a side elevational view, partially broken away and in section and showing an arrangement where a lug nut assembly does not provide for proper gripping action on the stud of a wheel.
Detailed Description of a Preferred Embodiment
Referring now in more detail and by reference characters to the drawings which illustrate a preferred embodiment of the present invention, FIG. 1 illustrates a conventional prior art arrangement for mounting an aluminum wheel, or other non-ferrous wheel, 10 to a hub 12 of a vehicle. The hub 12 is generally secured to and extends circumferentially around the axle of the vehicle and is adapted to receive any conventional wheel.
The plurality of threaded studs 14 (usually four to eight threaded studs) are circumferentially spaced about and extend outwardly from a flat surface of the vehicle hub. One of those studs 14 is more fully illustrated in FIG. 1 of the drawings and extends outwardly from a flat surface of the hub 12. Moreover the hub stud 14 is provided with an externally threaded section 16.
The conventional vehicle wheel, such as the aluminum wheel 10, is provided with a plurality of bolt holes 18, having cylindrically shaped regions which are sized and arranged to receive the outwardly extending studs on the vehicle hub 14. Moreover, the bolt holes 18 extend into and communicate with large nut receiving recesses 20 formed within the vehicle wheel 10 for receiving conventional lug nuts 22. A frustoconically shaped tapered wall 24 (a conically shaped region) extends between the recess 20 and the bolt hole 18, in the manner as illustrated in FIG. 1 of the drawings, in order to receive and to be engaged by a bearing surface 26 on a conventional lug nut 22.
In accordance with the above identified construction, a non-ferrous vehicle wheel may be mounted to the hub 12 of the vehicle by locating the various studs 14 in the bolt holes 18 of the wheel. Thereafter, the wheel is secured to the hub of the vehicle by tightening the lug nuts 22 on the externally threaded section 16 of each of the studs 14. In accordance with this prior art arrangement, the bearing surfaces 26 of the lug nuts will engage and bear against the frustoconical outwardly flaring surface 24 of the non-ferrous wheel 10.
As indicated previously, most conventional vehicles are constructed so as to receive steel wheels. When a steel wheel is mounted to the studs extending outwardly from the hub, there is generally no problem in providing a security fit and tight locking arrangement of the wheel on the vehicle hub. However, and as indicated previously, several problems do arise when attempting to mount a non-ferrous wheel to a vehicle hub.
Due to the fact that an aluminum or magnesium wheel is much softer than a steel wheel, and also due to the fact that it does not have the same inherent strength and rigidity, the aluminum wheel and the magnesium wheel often have thicker wall constructions in order to compensate for the lack of strength requirements which are inherent in the steel wheel. As a result, the lug nuts 22 are not capable of being tightened around the greater portion of the threaded section 16 of the length of the stud 14. FIG. 1 illustrates a problem which arises when a wheel of thicker sidewall than a steel wheel is mounted on a vehicle hub. It can be observed that the conventional lug nut engages the outwardly flaring frustoconical surface 24 at an appreciable distance from the face of the hub 12. Accordingly, only a few threads of the stud 14 are engaged by the lug nut 22.
As a result of the fact that there is not a tight securement of the lug nut on the stud, vibrational forces which inevitably arise during movement of the vehicle will cause the lug nut 22 to unwind on the shank of the stud 14. Furthermore, the unsupported length of the stud allows the stud to flex during rotation of the wheel and this, in turn, causes the nut to dig into the soft aluminum face and become loosened from the stud.
FIGS. 2 through 5 illustrate a lug nut assembly A used for securing an aluminum wheel or other non-ferrous wheel 10 to the studs 14 extending outwardly from the vehicle hub 12. The lug nut assembly A of the present invention generally comprises a lug nut 30 having a central body section 32 with an internally threaded cylindrical bore 34 extending therethrough. The body section 32 is provided with a plurality of tool engaging circumferentially arranged relatively flat surfaces 36 often referred to as tool engaging walls, which are located to receive the socket or flats of a conventional wrench.
At its inner end, that is the end facing the hub 12 of the vehicle, reference being made to FIG. 2, the body section 32 integrally merges into a tapered bearing face 38 which is sized to normally engage and bear against the frustoconical wall 24 in the conventional aluminum wheel or magnesium wheel. The tapered bearing wall 38 also integrally merges into an inwardly extending cylindrically shaped skirt 40 which is also integral with the body 32 of the lug nut. The skirt 40 is also provided with the internally threaded central bore sized to receive the externally threaded stud 14 on the hub 12 of the vehicle.
The lug nut assembly of the present invention is also provided with an insert 34 which is also formed of a ferrous material such as steel and which is also best illustrated in FIG. 4 of the drawings. It can be observed that the insert 44 comprises a conically shaped section in the form of an inwardly tapering head 46 which integrally merges into a cylindrically shaped section, such as a sleeve 48. The head 46 is provided with a conically shaped opening 50 generally conforming to the exterior shape of the head 46, in the manner as best illustrated in FIGS. 3 and 4 of the drawings. In like manner, the sleeve 48 is provided with a central bore 52 communicating with the opening 50. In this way, it can be seen that the insert has a conically shaped inner wall bearing against the conically shaped section on the body of the nut and a conically shaped outer wall bearing against the conically shaped region of the wheel. In like manner, the insert also has a cylindrically shaped inner wall section bearing against a substantial portion of the axial length of the skirt and also a cylindrically shaped outer wall bearing against the cylindrically shaped region of the wheel.
By further reference to FIG. 2, it can be observed that the insert 44 is adapted to fit snugly about the bearing wall 38 of the lug nut 30 and the skirt 40 of the lug nut. More specifically, it can be observed that the head 46 of the insert engages the bearing surface 38 and the sleeve 48 of the insert 44 snugly engages the skirt 40 on the lug nut. In addition, the exterior face of the head 46 of the insert engages the frustoconical surface 24 formed in the vehicle wheel and the exterior face of the sleeve 48 bears against the cylindrically shaped bore of the bolt hole formed in the vehicle wheel.
In accordance with the construction utilizing the nut lug assembly of the present invention, it can be observed that the lug nut can be tightly engaged against the steel insert 44 Moreover, the insert 44 generally conforms to and will bear against the surface of the aluminum or magnesium wheel surrounding the bolt hole. Inasmuch as the insert generally conforms to the surface of the material surrounding the bolt hole, there is a generally even distribution of forces. As a result, the insert does not bite into or otherwise distort the softer aluminum or magnesium wall. Furthermore, the skirt on the lug nut bears against the cylindrically shaped sleeve on the insert and in this way, the sleeve on the insert is captured between the skirt of the lug nut and the bore of the bolt hole formed in the wheel.
FIG. 6 illustrates the very undesirable situation which could arise if the insert were used with a lug nut which did not have a skirted portion thereon. In FIG. 6, it can be observed that while the steel cylindrically shaped sleeve bears against the surface of the material surrounding the bolt hole, there is no skirt portion or other material which provides rigidity to the vehicle stud. Accordingly, there is insufficient gripping of the lug nut on the vehicle stud.
Thus it has been established that a lug nut must engage at least a length of stud equivalent to at least one times the thread diameter for at least a minimum desired threaded engagement. The prior art lug nut arrangements used for mounting the aluminum and magnesium wheels did not afford this protection. However, the lug nut assembly of the present invention is more than adequate in meeting this minimum requirement. The lug nut arrangement of the present invention has been installed and tested on over 300,000 wheels and there has not been any one reported failure of a lug nut loosening or any other type of failure.
Thus, there has been illustrated and described a unique and novel lug nut assemby for securing a non-ferrous wheel to a hub of a vehicle and which utilizes a skirted lug nut and a ferrous insert therefore. Thus, the present invention fulfills all of the objects and advantages which have been sought therefore. It should be understood that many changes, modifications, variations and other uses and applications will become apparent to those skilled in the art after considering this specification and the accompanying drawings. Therefore, any and all such changes, modifications, variations, and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the following claims.