Abstract:
The present invention provides a suspension tuning device for vehicles with struts. More specifically, the suspension tuning device generally comprises a pair of plates constructed to mount juxtaposed to the strut/spindle mounting flange of a standard MacPherson strut, each plate includes an inset sub-plate having an offset aperture which cooperates with one of the spindle attachment bolts to control wheel camber.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application is based upon and claims priority from co-pending U.S. patent application Ser. No. 10/998,073, filed on Nov. 26, 2004, the entire disclosure of both which are hereby incorporated by reference in their entirety.  
       FIELD OF THE INVENTION  
       [0002]     The present invention relates to a device for quickly and easily adjusting camber of a vehicle front suspension across a broader than normal range to tune the vehicle&#39;s suspension for racing and/or high performance street applications.  
       BACKGROUND OF THE INVENTION  
       [0003]     The versatility and performance of newer muscle cars such as the FORD MUSTANG permit owners to use one vehicle for multiple purposes. Often the same vehicle used to carry groceries home from the supermarket is used for racing applications on the weekend. Owners will often modify their vehicle to make it more competitive in their chosen form of racing. One of the most modified areas of a vehicle for racing applications is the suspension.  
         [0004]     Front suspension tuning can be one of the most critical aspects of getting a vehicle to handle properly for either street or racing applications. Unfortunately, front suspensions that are modified exclusively for racing typically will not work properly for street driving, and street suspensions typically do not work well for racing. One of the biggest challenges for a muscle car owner who races his vehicle has been to balance the vehicle for both uses.  
         [0005]     The front wheel of a vehicle has three main alignment angles: camber, caster, and toe. Camber is the angle at which the top of the tire is tilted inwardly or outwardly, as viewed from the front of the car. If the top of the tires lean toward the center of the car you have negative camber. If the top of the tires are tilted outward you have positive camber. Typically, as the tires are turned left and right, the camber changes slightly because the pivoting points for the tires are not vertical as viewed from the side. Adjusting camber can have a dramatic affect on the cornering characteristics of a vehicle. For example, an oval track racer will often race with negative camber on the right side of the vehicle and positive camber on the left side of the vehicle. A drag racer will often race with neutral or slightly negative camber on both sides of the vehicle and a street vehicle will typically have camber set at zero or perpendicular to the street surface.  
         [0006]     Caster is the angle at which the pivot points for tires are tilted, as viewed from the side. Caster is best understood by imagining an axis running through the uppermost wheel pivot and extending through the lowermost pivot. From the side, if the top of the axis tilts toward the back of the car you have positive caster, if the axis line tilts toward the front of the car you have negative caster. If a vehicle has positive caster, the uppermost pivot is behind the lower pivot and this causes the tire to tilt in more at the top as the tire is steered inward (camber gain).  
         [0007]     Changing caster primarily affects four things: high speed stability, camber gain, bump steer characteristics, and relative corner weights (wedge). Increasing caster generally increases straight line directional stability. This is good for an application such as drag racing, however, other parameters such as bump steer and wedge may be adversely affected making handling for applications such as street driving or road racing unacceptable. Excessive caster settings will increase required steering effort, cause excessive tire wear and reduce braking ability. Negative caster requires less steering effort, but directional stability is adversely affected. Some racing applications may require different caster settings on each side of the vehicle. For example, oval track racers often run more positive caster on the right side wheel than the left. The caster split helps pull the car down into the turn, helps the car turn in the center of the turn, and helps the car maintain traction exiting the turn.  
         [0008]     Accordingly, what is lacking in the art is a suspension tuning kit for vehicles with struts. The suspension tuning kit should achieve objectives such as providing: quick adjustment, increased suspension rigidity, increased range of adjustability and reliable performance. The suspension tuning kit should include packaging flexibility for installation on various vehicle configurations including retrofitting existing vehicles with minimal modification of the original suspension system. The suspension tuning kit should facilitate independent caster and camber adjustment of each front wheel across the extended range. The suspension tuning kit should facilitate quick suspension changes to allow a vehicle to be driven to a racetrack, converted to a race setup, and thereafter quickly converted back to a street driving setup for the trip home.  
       SUMMARY OF THE INVENTION  
       [0009]     The present invention provides a suspension tuning device for vehicles with struts. More specifically, the suspension tuning device generally comprises a pair of plates constructed to mount juxtaposed to the strut/spindle mounting flange of a standard MacPherson strut, each plate includes an inset sub-plate having an offset aperture which cooperates with one of the spindle attachment bolts to control wheel camber. The cooperating plates and sub-plates permit front suspension camber alterations throughout an increased range when compared to the prior art.  
         [0010]     The pre-existing vehicle strut tower includes a thin sheet metal mounting member constructed for attaching the upper portion of a strut member via a stamped metal plate. The mounting member typically includes three elongated slots arranged to cooperate with the stamped metal plate to permit the upper portion of the strut member to be pivoted inward for a small amount of camber adjustment. When the upper portion of the strut is pivoted inwardly or outwardly the roll center of the vehicle is altered and vehicle handling and stability may be detrimentally affected.  
         [0011]     The instant invention provides a suspension tuning kit which operates in conjunction with, or replaces, the stamped metal strut attachment plate of the prior art. The instant invention is constructed of billet aluminum and includes a pair of camber plates. Each of the camber plates includes an inner surface and an outer surface, an upper aperture and a lower elongated aperture. The upper aperture and the lower elongated aperture are arranged to align with the pre-existing strut/spindle mounting apertures located in the OEM strut/spindle mounting flange. The camber plates include an outer contoured perimeter and a rounded lower edge which allow the plates to be snugly fit into the pre-existing strut/spindle mounting flange without interference. The plates fit within the flange sufficiently to allow the inner surfaces of the camber plates to lay juxtaposed to the outer surfaces of the strut/spindle mounting flange for a sandwich type assembly. The outer surface of each camber plate includes a generally rectangular cavity extending inwardly for accepting one of a plurality of offset-plates. The offset-plates have an outer perimeter shaped to conjugately match and fit into the camber plate cavity. Offset-plates are supplied in pairs and are constructed to include apertures positioned offset from the longitudinal centerline of the camber plates in predetermined increments for establishing the desired amount of wheel camber.  
         [0012]     In use, the bottom surface of a camber plate is positioned juxtaposed to the outer surfaces of the strut/spindle mounting flange. Matching offset-plates are inserted into the camber plate pockets. Fasteners extend through the camber plates, the offset-plates, and the strut/spindle mounting flanges to secure the spindle in a predetermined position with respect to the strut. The offset-plates are constructed and arranged to cooperate with the existing spindle attachment bolts to control the camber angle of the spindle and thus the respective wheel. This allows the user to select a pair of offset-plates constructed to establish a desired wheel camber setting. Further alterations of camber settings merely require selecting and changing the offset-plates to a new desired set-up. Wheel camber can thus be altered throughout an increased range without changing the strut angle or the roll center of the vehicle.  
         [0013]     In addition, the sandwich construction of the strut/spindle mounting flange and the camber plates assembly significantly increases rigidity and stability of the front suspension assembly. For further increased rigidity and stability, the kit may also include an upper strut mount adapted to replace the OEM stamped camber plate. The upper strut mount secures the upper end of the strut in a predetermined position with respect to the strut tower. The upper strut mount includes a centrally located bore constructed to cooperate with the top portion of the strut, and the outer portion of the upper strut mount includes a resilient, preferably urethane, element for isolating vibration. The upper mount is generally annular shaped with an enlarged head and preferably includes a threaded portion which extends upwardly through the mounting member of the vehicle&#39;s strut tower. A resilient element is placed on each side of the mounting member and a threaded nut cooperates with the threaded portion extending through the mounting member of the vehicle&#39;s strut tower to allow the upper portion of the strut to be secured in a selected position with respect to the strut tower.  
         [0014]     The suspension tuning kit may be installed on either one or both sides of the front suspension of the vehicle and the camber angle of each spindle may be independently adjusted to suit the drivers needs.  
         [0015]     Accordingly, it is an objective of the present invention to provide a suspension tuning kit for vehicles with struts.  
         [0016]     An additional objective of the present invention is to provide a suspension tuning kit for vehicles with struts which allows wheel camber changes without alteration of the vehicle&#39;s roll center.  
         [0017]     It is a further objective of the present invention to provide a suspension tuning kit for vehicles with struts that allows spindle angle alterations with respect to the strut to control wheel camber angle.  
         [0018]     A still further objective of the present invention is to provide a suspension tuning kit for vehicles with struts which includes sandwich construction to provide additional rigidity and support to the vehicle suspension system.  
         [0019]     Another objective of the present invention is to provide a suspension tuning kit for vehicles with struts which is simple to install and is ideally suited for original equipment and aftermarket installations.  
         [0020]     Yet another objective of the present invention is to provide a suspension tuning kit for vehicles with struts that can be inexpensively manufactured, and is simple and reliable in operation.  
         [0021]     Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]     The accompanying figures where like reference numerals refer to identical or functionally similar elements throughout the separate views, and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention.  
         [0023]      FIG. 1  is a perspective view illustrating the front portion of a vehicle equipped with strut front suspension;  
         [0024]      FIG. 2  is a perspective exploded view of the instant invention and a portion of the strut tower mounting member of the vehicle illustrated in  FIG. 1 ;  
         [0025]      FIG. 3  is a top view of the camber plate of the instant invention; and  
         [0026]      FIG. 4  is a section view of the camber plate taken along lines  1 - 1  of  FIG. 3 . 
     
    
     DETAILED DESCRIPTION  
       [0027]     As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting; but rather, to provide an understandable description of the invention.  
         [0028]     The terms “a” or “an”, as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms including and/or having, as used herein, are defined as comprising (i.e., open language). The term coupled, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically. The terms program, software application, and the like as used herein, are defined as a sequence of instructions designed for execution on a computer system. A program, computer program, or software application may include a subroutine, a function, a procedure, an object method, an object implementation, an executable application, an applet, a servlet, a source code, an object code, a shared library/dynamic load library and/or other sequence of instructions designed for execution on a computer system.  
         [0029]     Although the invention is described in terms of a preferred specific embodiment, it will be readily apparent to those skilled in this art that various modifications, rearrangements and substitutions can be made without departing from the spirit of the invention. The scope of the invention is defined by the claims appended hereto.  
         [0030]     Referring to  FIG. 1 , the front portion of a vehicle  10  equipped with a strut suspension is shown. The strut suspension  12  includes a pair of strut towers  14 . The strut towers are typically formed from sheet metal by methods well known in the art and are secured to the inner fender wall structure  18  on both the left side  20  and right side  22  of the vehicle. Each strut tower includes a mounting member  24  oriented in a plane substantially orthogonal with respect to the longitudinal axis  32  of the corresponding strut  16 . The mounting member  24  generally includes a strut aperture  26  and three elongated camber adjustment slots  28 . The elongated camber adjustment slots are arranged generally parallel with respect to each other and spaced around the strut axis  32 . The upper end of a strut member  16  is secured to the mounting member via a stamped sheet metal member  30 . The sheet metal member  30  cooperates with the three camber adjustment slots  28  to permit the upper end of the strut member to be pivoted inward toward the center of the car for a small amount of camber adjustment.  
         [0031]     Referring to  FIG. 2 , an exploded view of the instant invention is illustrated in conjunction with a standard strut member  16 , the spring member is omitted for clarity. The instant invention provides a suspension tuning kit  100  which replaces the stamped metal strut attachment plate  30  ( FIG. 1 ) of the prior art. The suspension tuning kit  100  comprises a pair of camber plates  102  and at least one pair of offset-plates  104 .  
         [0032]     Referring to  FIGS. 2-4 , the camber plate  102  includes an inner surface  106 , an outer surface  108 , a top end  110 , a bottom end  111 , a contoured perimeter  112 , a rounded bottom edge  114 , and a longitudinal centerline  116 . The top end  110  includes a first transverse bore  118  positioned generally along the longitudinal centerline  116 . The first transverse bore  118  is generally positioned to align with the top spindle attachment fastener  120  and the top strut/spindle flange aperture  122 . The bottom end  111  includes a second elongated transverse bore  124 . The second transverse bore  124  is positioned to align with a bottom spindle attachment fastener  126  and the bottom strut/spindle flange aperture  128 . While the bottom strut/spindle flange aperture  128  is generally provided from the OEM supplier as a round aperture, the instant invention preferably utilizes an elongated arcuate shaped aperture. The OEM aperture may be modified by means well known in the art such as die grinders, files, milling machines and the like.  
         [0033]     When the inner surfaces  106  of the camber plates  102  are positioned juxtaposed to an outer surface  130  of the strut/spindle flange  134  the rounded bottom edge  114  allows the camber plate  102  to abut the depending support lip  132  without interference.  
         [0034]     The camber plate  102  also includes a contoured cavity  135  which extends inward into the camber plate  102  from the outer surface  108  and the second transverse bore  124  is centrally located within the contoured cavity. The cavity  135  is generally constructed and arranged to secure and locate an offset-plate  136 . The offset-plate  136  includes an outer perimeter  138  conjugately shaped with respect to the cavity  135  so that the offset plate  136  fits snugly into the cavity. Located in the offset-plate is an offset aperture  140 . The aperture  140  is offset a predetermined amount with respect to the camber plate longitudinal centerline  116 . In a most preferred embodiment the kit  100  is supplied with a plurality of pairs of offset-plates  136  with each pair having apertures  140  offset in predetermined increments. In this embodiment, each set of offset-plates are constructed to result in a different amount of wheel camber when assembled. For example, the offset plates  136  could include apertures  140  that allow camber adjustment from negative three degrees to positive six degrees. The apertures in the offset-plates are preferably positioned for one half degree increments in camber angle, however, the plates may be constructed to include any desired offset increment without departing from the scope of the invention. It should be appreciated that the cavity  135  and the cooperating offset-plates  136  could also be utilized at the top end  110  of the camber plates  102  without departing from the scope of the invention.  
         [0035]     In a most preferred and non-limiting embodiment, the camber plates  102  are constructed of billet aluminum and are about 0.350 of an inch thick and the cavity depth is about 0.120. It should be appreciated that the camber plate  102  may be made thinner or thicker, and the cavity  135  depth may be varied as the space requirements, materials and wheel loads require. In the most preferred embodiment, the offset-plates  102  are constructed of steel and are about one eighth of an inch thick. It should also be appreciated that to accommodate space, material and wheel load requirements the camber plate  102  and/or the offset-plates  136  may alternatively be made from other ferrous or non-ferrous metals which may include, but should not be limited to, steel, titanium, brass, bronze or suitable combinations thereof.  
         [0036]     In use, the camber plates  102  are positioned parallel and juxtaposed to the outer surface of the strut/spindle flange and offset-plates are selected for the desired wheel camber and are thereafter inserted into the cavities. Threaded fasteners  120  and  126  extend through the first and second transverse bores  118 ,  124 , offset apertures  140 , strut/spindle bores  122 ,  128 , and spindle bores  142 ,  144  to cooperate with threaded nuts  146 . The thickness and contour of the camber plates cooperate with the strut/spindle mounting flange  134  and its depending lip  132  to create a sandwich type of construction that has substantially increased rigidity and strength when compared to the OEM configuration. In this manner, the front wheel camber of a vehicle may be selectively adjusted throughout an extended range.  
         [0037]     Referring to  FIGS. 1 and 2 , the upper strut mount  148  is illustrated. In general, the upper strut mount is constructed and arranged to replace the stamped sheet metal OEM upper strut mount  30  ( FIG. 1 ). The upper strut mount  148  includes a head portion  150 , an annular portion  152 , a pair of resilient members  154 , and a threaded nut member  156 . The annular portion  152  includes a central bore  158  sized to fit over the upper portion of the strut member  16 . The outer surface of the annular portion  152  includes integrally formed threads which cooperate with an internal threaded surface in nut member  156 . In use, the central bore  158  is placed over the upper end of the strut member and the annular portion  152  is extended upwardly through the mounting member  24  of the vehicle&#39;s strut tower  14 . A resilient element  154  is placed on each side of the mounting member  24  and the threaded nut cooperates with the external threads extending through the mounting member of the vehicle&#39;s strut tower to allow the upper portion of the strut to be secured in a selected position with respect to the strut tower.  
         [0038]     In a most preferred and non-limiting embodiment, the upper mount is constructed of billet aluminum; however, it should be noted that other metals well known in the art which may include but should not be limited to steel, titanium and the like may also be utilized.  
         [0039]     All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.  
         [0040]     It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification.  
         [0041]     One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.  
         [0042]     Although specific embodiments of the invention have been disclosed, those having ordinary skill in the art will understand that changes can be made to the specific embodiments without departing from the spirit and scope of the invention. The scope of the invention is not to be restricted, therefore, to the specific embodiments, and it is intended that the appended claims cover any and all such applications, modifications, and embodiments within the scope of the present invention.