Abstract:
An apparatus is described for increasing a range of adjustment of a suspension system. The apparatus includes a cam bolt having an internal cam feature and external cam feature that together allow for increased range of adjustment.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the filing benefit and priority of U.S. Provisional Application Ser. No. 61/878,914 filed Sep. 17, 2013, the contents which are incorporated herein by reference in its entirety. 
    
    
     FEDERAL SPONSORSHIP 
     Not Applicable 
     JOINT RESEARCH AGREEMENT 
     Not Applicable 
     TECHNICAL FIELD 
     The present invention relates to a fastener apparatus generally, and more particularly to a cam bolt apparatus for providing alignment adjustment in an automotive suspension system. 
     BACKGROUND 
     Cam bolt apparatus are used in automotive vehicle suspensions to provide adjustment between respective components of the suspension system to control wheel alignment, such as camber, caster, and/or tow alignment. Cam bolt apparatus typically include a bolt, a first cam washer fixed to the bolt proximate to the bolt head, a second cam washer engaged to a shank of the bolt distal from the bolt head, and a nut that may be threaded onto a threaded portion of the bolt to secure the bolt to a cam bracket. The bolt and the cam washers are eccentrically arranged, such that rotation of the apparatus about a cam washer adjusts a position of a longitudinal axis of the bolt within accommodating slots formed in the cam bracket. With a control arm or other suspension component linked to the cam bolt, such positional adjustment correspondingly adjusts the automotive suspension component position, thereby affecting a suspension alignment characteristic, such as wheel camber. 
     The extent of suspension characteristic adjustment afforded by the above described conventional cam bolt apparatus is limited by the degree of eccentricity of the cam bolt to the cam washer axis. The degree of suspension adjustment has therefore been limited to the eccentric offset, which is typically between about 0.5-3° degrees of adjustment. In some circumstances, such an adjustment range has proven to be insufficient. There is accordingly a need to increase the extent of suspension alignment adjustment afforded by a cam bolt apparatus. 
     SUMMARY 
     Embodiments according to aspects of the invention include an apparatus for adjusting a position of members of a suspension system. In an embodiment of the invention, the apparatus includes a bolt having an eccentric inner cam portion and an eccentric outer cam portion. The bolt includes a shaft having a first threaded portion and a second enlarged head portion, where the shaft, threaded portion and enlarged head portion have a central longitudinal axis. The bolt also includes outer eccentric cams or first and second washers fixed to the bolt. The first washer is fixed to the bolt adjacent the first threaded portion and the second washer is fixed to the bolt adjacent the enlarged head portion. The washers are fixed to the bolt so that a center axis of both of the washers is offset from the central axis of the bolt. An inner eccentric cam or lobe extends outwardly from a portion of the shaft between the first and second eccentric washers. The lobe includes a longitudinal center axis offset from the central longitudinal axis of the bolt. 
     Further, the central axis of the bolt, the center axis of the first and second washers and the center axis of the lobe are planar. Alternatively, the central axis of the bolt, the center axis of the first and second washers and the center axis of the lobe are not planar. In an embodiment of the invention the first washer is removably fixed to the bolt with a keyed slot. A further embodiment of the invention includes a suspension adjustment bracket that has elongated slots to receive the bolt and includes flanges extending from the bracket to engage the first and second washers on opposing sides of the washer. 
     The accompanying drawings, which are incorporated in and constitute a portion of this specification, illustrate embodiments of the invention and, together with the detailed description, serve to further explain the invention. The embodiments illustrated herein are presently preferred; however, it should be understood, that the invention is not limited to the precise arrangements and instrumentalities shown. For a fuller understanding of the nature and advantages of the invention, reference should be made to the detailed description in conjunction with the accompanying drawings. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       In the various figures, which are not necessarily drawn to scale, like numerals throughout the figures identify substantially similar components. 
         FIG. 1  is a front end perspective view of a portion of a suspension system in accordance with an embodiment of the invention; 
         FIG. 2  is a front opposing end perspective view of a portion of a suspension system of the type shown in  FIG. 1 ; 
         FIG. 3  is a front end perspective view of a portion of a bracket and cam bolt in accordance with an embodiment of the invent; 
         FIG. 4  is a front opposing end perspective view of the bracket and cam bolt of the type shown in  FIG. 3 ; 
         FIG. 5  is a top plan view of the bracket and cam bolt of the type shown in  FIG. 3 ; 
         FIG. 6  is a front perspective view of the bracket and cam bolt of the type shown in  FIG. 3 ; 
         FIG. 7  is a front first end perspective view of a cam bolt in accordance with an embodiment of the invention; 
         FIG. 8  is a back first end perspective view of the cam bolt of the type shown in  FIG. 7 ; 
         FIG. 9  is a back perspective view of the cam bolt of the type shown in  FIG. 7 ; 
         FIG. 10  is a perspective view of a portion of a bracket of a suspension system in accordance with an embodiment of the invention; 
         FIG. 11  is a perspective view of the bracket of the type shown in  FIG. 10  having a cam bolt inserted and engaged with the bracket in accordance with an embodiment of the invention; 
         FIG. 12  is a bottom back end perspective view of the bracket and cam bolt of the type shown in  FIG. 11 ; and 
         FIG. 13  is a bottom back opposing end perspective view of the bracket and cam bolt of the type shown in  FIG. 12 . 
     
    
    
     DETAILED DESCRIPTION 
     The following description provides detail of various embodiments of the invention, one or more examples of which are set forth below. Each of these embodiments are provided by way of explanation of the invention, and not intended to be a limitation of the invention. Further, those skilled in the art will appreciate that various modifications and variations may be made in the present invention without departing from the scope or spirit of the invention. By way of example, those skilled in the art will recognize that features illustrated or described as part of one embodiment, may be used in another embodiment to yield a still further embodiment. Thus, it is intended that the present invention also cover such modifications and variations that come within the scope of the appended claims and their equivalents. 
     The suspension system  10  of the present invention generally includes a suspension linkage  12 , bracket or frame  14 , and cam bolt  20 .  FIGS. 1 and 2  illustrates a suspension linkage  12  coupled to the bracket or frame  14  by the cam bolt apparatus  20 . The suspension linkage  12  may be from, for example, a wheel assembly arm, such as an upper or lower control arm, and the bracket  14  may be secured to or formed as a portion of a vehicle frame. The suspension linkage  12  may be positioned between opposed sides  82  and  92  of bracket  14 , such that a cam bolt  20  extends through an aperture of the linkage  12  and slots  84  and  94  of the bracket  14  to secure the linkage  12  to the bracket. 
     With reference to  FIGS. 3-6 , cam bolt apparatus  20  is shown secured to the bracket  14  without linkage  12 . Cam bolt  20  includes a shank or shaft  22  having a first threaded portion  24  formed on a first end  26  of the shaft  22  and a second enlarged head portion  28  formed on a second end  30  of the shaft  22 . The enlarged head portion  28  is shown configured as a hexagonal head formed at an end of the shaft  22 , such that rotation of head  28  with a tool or other positioning device correspondingly rotates shaft  22 . The threaded portion  24  of shaft  22  is configured to receive a securement nut  40  for securing cam bolt  20  to the bracket  14 . 
     With further reference to  FIGS. 7-9 , cam bolt  20  further includes first and second cam washers  42  and  44  fixed to the shaft  22 . In some embodiments, first washer  42  may be secured to and fixed to the shaft  22  of cam bolt  20  via a keyed slot  50  and key  52  formed on an aperture of the washer  42 . Second washer  44  may be press fit, engaged, welded, formed integral or otherwise fixedly secured to the shaft  22  proximate to and adjacent the hexagonal head  28 . Accordingly, first and second washers  42  and  44  rotate simultaneous with and in conjunction with rotation of shaft  22 . Keyed slot  50  may represent, for example, a flat region in an otherwise circular cross-section of the first end  26  of shaft  22 . The keyed slot or flat  50  may be machined along the first threaded portion  24 , wherein the slot  50  cooperates with a configuration formed in the aperture of the washer  42  which acts as the key  52 . In this manner, the engagement between key  52  and the slot  50  formed in the shaft  22  restricts or prevents relative rotation between the washer  42  and shaft  22 . Various key and key-hole arrangements are known in the art, and are contemplated as being useful in the present invention. 
     The center axis of apertures extending through each washer is offset from the respective centers of first and second washers  42  and  44  such that when the washers are engaged to the cam bolt  20 , the center axis  46  of the washers is offset from and eccentric from the central longitudinal axis  32  of the shaft  22  (See  FIG. 9 ). A lobe  60  extends from a mid-region of the shaft  22  and, although circular in cross section in some embodiments, the lobe  60  has a center axis  62  that is offset or eccentric to both the center axis  46  of the washers and the central longitudinal axis  32  of the shaft  22 . Further, in embodiments of the invention the threaded end portion  24 , head portion  28  and shaft  22  may all share a common central longitudinal axis  32 . Depending upon the purpose and desired adjustment, the central longitudinal axis  32  of the shaft, the center axis  46  of the washers, and the center axis  62  of the lobe may be aligned planar or may be aligned so that all three axis do not lie in the same plane. 
     With reference to  FIG. 10 , the bracket  14  includes elongated slots  84  and  94  extending through respective sides  82  and  92  of the bracket. Ridges or flanges  86  and  88  corresponding with slot  84  and ridges or flanges  96  and  98  corresponding with slot  94  extend from respective sides  82  and  92  of bracket  14 . The flange pairs are aligned on opposing ends of each elongated slot and are spaced apart a distance so that the outer diameters of washers  42  and  44  are slightly less than the distance between the flanges. In this manner, when the hex head  28  is turned the washers rotate but are contained between the flanges while the bolt slides in the elongated slot dependent upon the orientation or position of the center axis  46  of the washers relative to the central longitudinal axis of the shaft  22 . The flanges, therefore, provide cam bearing surfaces engaging respective outer edges or races  48  of first and second cam washers  42  and  44  to brace first and second washers  42  and  44  against longitudinal movement. Slots  84  and  94  likewise brace against shaft  22  to restrict or limit movement of bolt  20  along the elongated slot. 
     In use, the user may insert the free or first end  26  of the shaft  22  through slot  94 , the aperture of the linkage  12 , and slot  84  until washer  44  engages between flanges  96  and  98 . Washer  42  is then engaged on the shaft  22  aligning the key  52  in the keyed slot  50  and pressing the washer in position between flanges  86  and  88 . Securement nut  40  is then rotated onto the shaft around the threaded portion  24  until an inner shoulder of the nut  40  engages the washer  42 , thereby restricting the cam bolt  20  within the bracket  14 . Rotation of cam bolt  20  results in corresponding rotary movement of first and second cam washers  42  and  44 . Since first and second cam washers  42  and  44  are held against lateral movement by corresponding flanges, such rotation of first and second washers  42  and  44  results in movement of shaft  22  within first and second slots  84  and  94 . This movement causes a shifting of the position of the suspension linkage  12  relative to the bracket  14 . Depending upon the orientation of the center axis of the shaft, lobe and washers, the user may correspondingly adjusts a suspension characteristic, such as wheel camber. The extent of such adjustment is limited by the movement of shaft  22  within slots  84  and  94  and the orientation of the lobe on the shaft  22 . It has been found that, in some cases, the extent of adjustment available in conventional systems is insufficient. 
     In order to enhance the extent of adjustment available in the cam bolt apparatus  20 , the eccentricity of lobe  60  accentuates the movement of the linkage  12  as cam bolt  20  moves within first and second slots  84  and  94  from rotation of cam bolt  20 , as described above. Lobe  60  may be configured with a circular or non-circular cross-section, and preferably includes an apex portion that is a maximal radial distance from the non-lobed portions of shaft  22 . In some embodiments, the apex of the lobe  60  may be arranged radially outwardly from shaft  22  in a manner that coincides with the eccentricity of shaft  22  with respect to first and second cam washers  42  and  44 . In other words, lobe  60  may form an apex portion  60  within a plane containing shaft axis  32  and cam washer center axis  46 , so as to most accentuate movement of the linkage  12  along a path of the slot, through the rotational adjustment of cam bolt apparatus  20 , as described above. Cam bolt  20  may include lobe  60  at only a single side thereof, such that the resultant structure is asymmetrical with respect to shaft axis  32 . In one embodiment, the diameter of shaft  22  may be about 0.36 inches while the diameter of the lobe  60  may be about 0.48 inches. 
     These and various other aspects and features of the invention are described with the intent to be illustrative, and not restrictive. This invention has been described herein with detail in order to comply with the patent statutes and to provide those skilled in the art with information needed to apply the novel principles and to construct and use such specialized components as are required. It is to be understood, however, that the invention can be carried out by specifically different constructions, and that various modifications, both as to the construction and operating procedures, can be accomplished without departing from the scope of the invention. Further, in the appended dams, the transitional terms comprising and including are used in the open ended sense in that elements in addition to those enumerated may also be present. Other examples will be apparent to those of skill in the art upon reviewing this document.