Abstract:
Replacement ball joint apparatus and methods for conveniently modifying motor vehicle suspension camber, caster or camber/caster combination angle by means of repositioning a wheel spindle top or bottom relative to a control arm. The apparatus includes a module securing one end of a ball joint which is connectable at its other end to the spindle, the module having guide slots at an upper surface thereof and a threaded bore therein. An insert is securable at the control arm and has an elongated slot through which a bolt is received and engageable at the threaded bore in the module. Protruding guides are defined at a surface of the insert, the guides and guide slots being engageble for maintenance of module orientation.

Description:
RELATED APPLICATION 
     This application is a Continuation-In-Part of pending U.S. patent application Ser. No. 09/703,780 filed on Oct. 31, 2000 by Robert M. Allman and James H. Garrard and entitled “APPARATUS AND METHOD PROVIDING ADJUSTABLE VEHICLE BALL JOINT POSITIONING”. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to wheel adjustment/alignment apparatus and methods for vehicles, and, more particularly, relates to apparatus and methods for adjusting the control arm/wheel spindle relationship at an upper or lower ball joint connection to produce changes in the camber, caster or camber/caster combination angle of a vehicle wheel. 
     BACKGROUND OF THE INVENTION 
     Most vehicles consist of a tire/wheel mounted to a spindle which is attached to the vehicle through upper and lower control arms with the main connection being through ball joints mounted to the control arms. Some vehicles, however, are manufactured without provision for adjusting camber angle in the wheels. For example, some vehicles utilize an ‘A’ shaped upper control arm with ‘silent-bloc’ type pivot isolators pressed into the inner pivot locations of the arm. The inner control arm in some such cases has a ‘u’ shaped bracket welded into it, with cross-holes in the inner bracket and inner control arm for locating the mounting bolts that engage and clamp the ‘silent-bloc’ pivot isolators. This arrangement locates the inner pivots of the upper control arm in a fixed position with no means of adjustment. 
     The camber and caster angles of the tire/wheel (relative to the vehicle frame) directly effect vehicle handling and tire wear and is therefore of great importance. Camber angle is typically specified by the factory at a specific vehicle ride height (the distance from the ground to some point in the vehicle suspension corresponding to the vehicle frame center of gravity). The camber angle established between the plane of the tire and wheel and the vertical plane through the vehicle frame is directly impacted by any changes in the suspension components. Such changes can occur through damage to the components or through modification, intentional or unintentional, to the vehicle ride height. Thus, vehicles with raised or lowered ride height or damaged suspension links will typically not maintain proper camber angle and require means for readjusting the camber angle to the original specifications if handling and tire longevity are not to be sacrificed. Moreover, it may become desirable to correct a mis-aligned vehicle with other than strictly camber corrections. 
     One current means for adjusting camber angle consists of changing the relative position of the control arm to the vehicle at the body mounting points. This allows the control arm, and thus the ball joint position, to be moved laterally with respect to the vehicle, thereby changing the camber angle of the spindle and the tire/wheel. This method will not work if the vehicle&#39;s control arm mounting scheme prevents replacing the fixed control arm body mounts with an adjustable mounting apparatus. 
     Another current means for adjusting camber angle provides for replacement of the upper or lower ball joint with an offset ball joint that, when rotated, allows changes of the position of the spindle mounting point around an offset arc. While this enables the camber angle to be modified, it at the same time modifies the caster angle, sometimes undesirably, due to its fixed radial offset arc. 
     In most vehicles, there is sufficient room for the suspension to translate up and down, as road conditions require, without contacting any parts of the vehicle body in the wheel well. However, when a vehicle&#39;s ride height has been modified lower there is less room for suspension travel. To allow for necessary corrections to camber angle in such cases, adjustable replacement devices must not require excessive room or unduly raise the control arm relative to the wheel thereby reducing the amount of vertical clearance in the wheel well and thus further limit the ability for the suspension to translate without contacting the vehicle body in the wheel well. A means of providing significant camber angle adjustment with minimal vertical height addition would thus be desirable. Further improvements could therefore be utilized. 
     SUMMARY OF THE INVENTION 
     This invention provides apparatus for selective positioning of a vehicle ball joint relative to a control arm to provide adjustability of wheel camber, wheel caster, and/or a combination of wheel camber and caster. The apparatus is simple to install and adjust, requires no modification of other suspension components, provides for adjustment of wheel camber independent of caster adjustment, and utilizes a minimal amount of space. 
     The apparatus includes a module configured to secure an end of the ball joint. A threaded bore and an orientation guide are defined at one surface of the module. An insert is securable at the control arm and has a mating orientation guide structure at one surface thereof engageable with the orientation guide of the module. A threaded stud is mounted through the slot of the insert and engages the threaded bore of the module, the stud movable linearly in the insert slot. 
     A ball joint is retained at a cavity through one surface of a body of the module and adjacent to the threaded bore. A cover secures the ball joint at the cavity, one surface of the body and the cover defining the orientation guide. The ball joint is affixable at an end protruding from the body to the vehicle&#39;s wheel spindle. 
     The mating orientation guide structure of the insert is preferable protruding guide pins, and the orientation guide of the module preferably mating slots. The insert is held at the control arm with a selected alignment of the slot relative to the control arm. The ball joint is fit into the cavity of the body of the module with the cover secured thereover at the body, the guide slots of the body/cover of the module and the protruding guides of the insert being aligned. The stud is located at a selected location linearly in the elongated slot of the insert before being tightened in the threaded bore. 
     It is therefore an object of this invention to provide apparatus for selective positioning of a vehicle ball joint relative to a control arm to provide adjustability of wheel camber, wheel caster, and/or a combination of wheel camber and caster. 
     It is another object of this invention to provide an apparatus for selective vehicle wheel angle positioning that is simple to install and adjust on a vehicle, requires no modification of other suspension components, provides for adjustment of wheel camber independent of caster adjustment, and utilizes a minimal amount of space. 
     It is still another object of this invention to provide an apparatus for selective positioning of a vehicle ball joint securable between a control arm and a wheel mounting, the apparatus including a module configured to secure an end of the ball joint and including a threaded bore thereat and an orientation guide at one surface thereof, an insert securable at the control arm and having a mating orientation guide structure at one surface thereof engageable at the orientation guide of the module for rotationally stabilizing the module thereat, the insert having a slot therethrough, and a threaded stud mountable through the slot of the insert and engageable by the threaded bore of the module, the stud movable linearly at the slot of the insert. 
     It is yet another object of this invention to provide an apparatus mountable at a vehicle control arm opening and at a spindle to provide selectable camber correction of a vehicle wheel that includes an insert having a slot, the insert extendible through the control arm opening and having an orientation guide structure at one surface thereof, a ball joint retaining module including a body and a cover, one surface of the body and the cover defining an orientation guide receivable at the orientation guide structure of the insert, the body having a cavity therein through the one surface that is secured by the cover, a ball joint affixable at one end to the spindle and at another end in the cavity in the body of the module, and a stud engageable at a selected position through the slot of the insert with the ball joint retaining module. 
     It is yet another object of this invention to provide an apparatus providing camber angle adjustability of a vehicle wheel that includes an insert having protruding guides and an elongated slot therethrough, a ball joint module including a ball joint, a body with a threaded bore adjacent to a cavity, and a cover, at least the cover having guide slots thereat, and a bolt engageable through the slot of the insert and at the threaded bore of the body of the module, wherein the insert is held at a vehicle suspension control arm member with a selected alignment of the slot relative to the control arm member, the ball joint is fit into the cavity of the body of the module with the cover secured thereover at the body, the guide slots of the cover of the module and the protruding guides of the insert are aligned, and the bolt is located at a selected location linearly in the elongated slot of the insert before being tightened in the threaded bore. 
     With these and other objects in view, which will become apparent to one skilled in the art as the description proceeds, this invention resides in the novel construction, combination, and arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that changes in the precise embodiment of the herein disclosed invention are meant to be included as come within the scope of the claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings illustrate a complete embodiment of the invention according to the best mode so far devised for the practical application of the principles thereof, and in which: 
     FIG. 1 illustrates one typical suspension system on a vehicle as supplied by a manufacturer; 
     FIG. 2 illustrates the suspension system of FIG. 1 with a first embodiment of the apparatus of this invention installed; 
     FIG. 3 is a perspective view of the camber/caster adjusting apparatus of FIG. 2; 
     FIG. 4 is a front elevation view of the apparatus of FIG. 3; 
     FIG. 5 is a side elevation view of the apparatus of FIG. 3; 
     FIG. 6 is a top elevation view of the apparatus of FIG. 3; 
     FIG. 7 is a sectional view taken along section line  7 — 7  of FIG. 4; 
     FIG. 8 is an exploded view of the camber/caster adjusting apparatus of FIG. 3; 
     FIG. 9 illustrates the suspension system of FIG. 1 with a second and, for purposes of this application, preferred embodiment of the apparatus of this invention installed; 
     FIG. 10 is a perspective view of the camber/caster adjusting apparatus of FIG. 9; 
     FIG. 11 is a front elevation view of the apparatus of FIG. 10; 
     FIG. 12 is a side elevation view of the apparatus of FIG. 10; 
     FIG. 13 is a top elevation view of the apparatus of FIG. 3; 
     FIG. 14 is a sectional view taken along section line  14 — 14  of FIG. 11; and 
     FIG. 15 is an exploded view of the camber/caster adjusting apparatus of FIG.  10 . 
    
    
     DESCRIPTION OF THE INVENTION 
     FIG. 1 illustrates a typical suspension system on a vehicle as supplied by the manufacturer. Upper control arm  10  and lower control arm  12  are both attached to the vehicle frame (not shown). Spindle  14 , which includes wheel mount  16  for supporting a wheel with a tire mounted thereon (not shown), is pivotably attached to each control arm through upper ball joint  18  and lower ball joint  19 , the ball joints spaced a fixed distance apart by spindle  14 . 
     FIG. 2 shows the suspension of FIG. 1 with a first embodiment of the camber/caster adjusting apparatus of this invention replacing the factory ball joint  18  for selective translation of the position of the upper ball joint along a linear distance “Y”, either inward towards the vehicle frame or outward away from the vehicle frame. When set as illustrated and discussed in greater detail hereinbelow, the effect of movement in the “Y” direction will be to decrease or increase, respectively, the camber angle established by the plane of the tire and wheel with the vertical plane of the vehicle frame in the direction from front to back of the vehicle. While use with the upper ball joint is illustrated herein, the apparatus could be applied to replace lower ball joint  19  and/or applied at both locations. 
     Camber/caster adjusting apparatus  20 , as shown in FIGS. 3 through 8, includes guide assembly  21  and mount assembly  22 . Guide assembly  21  includes insert  23  and guide plate  24  maintained at opposite sides of control arm opening  25  (see FIG.  8 ). Mount assembly  22  includes slide  26  having offset stud  28  extending therefrom through opening  29 . Ball joint  30  is held at slide  26  by collar  32 . The apparatus is held in relative positions, as discussed hereinafter, by fastener  34  (for example a flange nut), ball joint  30  affixable at spindle  14  conventionally. 
     Insert  23  is pressed into opening  25  of upper control arm  10  (and/or lower control arm  12 ) in place of the factory supplied ball joint ( 18  of FIG.  1 ). For camber only adjustment, insert  23  is oriented along the neutral caster angle by alignment of orientation mark  35  on the control arm (see FIG. 2) and a corresponding dimple or other orientation mark  36  on insert  23 . Guide plate  24  and insert  23  each have a slot  38  and  40 , respectively, which are substantially coextensive and along which stud  28  is linearly movable. Substantially parallel guide ridges  42  and  44  at guide plate  24  maintain rotational stability and guide linear movement of slide body  46  of slide  26 , by guiding engagement adjacent to spaced substantially parallel edges  48  and  50  of slide body  46 . 
     While a particular structure is shown for the guiding and stabilizing interrelationship of guide plate  24  and slide  26 , many different configurations at guide plate  24  and mating configuration at slide  26  could be utilized to achieve the same purpose. For example, the guide ridges may be positioned at slide  26  and the matable edges at guide plate  24 , or multiple spaced channels or a single centered channel could be provided at either guide plate  24  or slide  26  with corresponding structure at the other configured to ride in the channel or channels. 
     Insert  23  includes a flange  52  and rim  54 , slot  40  defined through rim  54 . Rim  54  extends through opening  25  of control arm  10  and is received adjacent to annular extension  56  of guide plate  24 . Ball joint  30  is secured at slide  26  by means of a press fit of ball joint end  58  and slide  26  into collar  32  with the addition of a staking process to provide a material deformation of collar end  60  over annular lip  62  of slide  26  to mechanically retain the unit (see FIG.  7 ). Ball joint  30  may be a factory supplied ball joint and is attached at its other end to spindle  14  using conventional means (applying nut and pin assembly  64  to lower threaded stud  66  after application thereof through opening  67  of spindle  14 , for example). 
     When ball joint  30  is connected to slide  26 , it can be seen that the central longitudinal axis of stud  28  is offset relative to the central longitudinal axis of ball joint  30 . This offset provides greater extent of wheel angle adjustability, since neutral adjustment, corresponding to alignment of the central axis of ball joint  30  (vertical axis in the FIGURES) with the central axis of opening  25  in control arm  10  (and thus the central axis of insert  23 ), locates stud  28  near an end slots  38  and  40  of guide plate  24  and insert  23 . 
     In use, insert  23  is installed into opening  25  of vehicle suspension control arm  10  (or other selected member) with orientation mark  36  at a selected position to achieve the desired direction of angle adjustability. For example, to allow camber only adjustment, insert  23  should be mounted with marks  35  and  36  aligned as shown in FIGS. 2 and 8 (caster neutral alignment), so that the length of slots  38  and  40  of guide plate  24  and insert  23  are also aligned with the guide marks. 
     Guide plate  24 , with slide  26  thereat having stud  28  extending through slot  38 , is positioned at the opposite side of control arm  10 . Ball joint  30  may be attached to spindle  14  in advance of or after installation of mount assembly  22  at guide assembly  21  with stud  28  extending through slot  40  of insert  23  (and thus through opening  25  of control arm  10 ) and held by nut  34 . Slide  26 , with edges  46  and  48  engaging ridges  42  and  44  of guide plate  24  to stabilize and guide slide  26 , when moved in guide plate  24  allows only linear movement of stud  28  in opening  25  perpendicular to the axis of the opening. This sliding movement provides tire/wheel camber adjustment without affecting caster angle (when aligned for caster neutral adjustment as shown in FIG.  2 ). When the desired angle is achieved (with ball joint  30  and the central axis of opening  25  of control arm  10  in a selected relative position), nut  34  is tightened to retain the interrelationship of the components thus established by securing stud  28  at the selected position relative to the axis of opening  25  and along slots  38 / 40  and slide  26  at guide plate  24 . 
     Should readjustment be desired, nut  34  may be loosened and mount assembly  22  of apparatus  20  can be moved inward (towards the vehicle frame) or outwards (away from the frame) by moving threaded stud  28  in guide assembly slots  38 / 40  until the corrected angle is achieved. The position of apparatus  20  is then fixed by applying sufficient torque to flange nut  30 . 
     As may be appreciated, the above described apparatus of this invention could be modified for installation in such a way as to affect only caster angle or in such a way as to affect both caster and camber angles. A geometric relationship exists between the upper and lower wheel spindle connections (ball joints  18  and  19 ) and the camber and caster angles of the wheel to the vehicle. As previously indicated, altering the position of one of the ball joints in the neutral caster direction affects the camber angle in a desired fashion. Extending this to caster and camber/caster combination corrections and adjustments, the camber/caster adjusting apparatus of this invention can be used to adjust caster only angles or some combination of camber and caster. If so desired, by rotating insert  23  to another position of orientation mark  36  relative to mark  35  on upper control arm  10  during installation, camber/caster adjusting apparatus  20  can be rotated in a predetermined fashion to provide for adjustment of caster only or some combination of camber and caster angles. 
     For vehicles that, for whatever reason, have less vertical clearances between the wheel well and the upper control arm, a second and, for such applications, now preferred embodiment of the apparatus of this invention is illustrated in FIGS. 9 through 15. The mechanism incorporates the sliding characteristics of the previously illustrated embodiment while increasing the stud to ball joint offset so the stud anchoring function can be moved from over the ball joint to adjacent to it. As will be seen, the result is a significant reduction in vertical height since the large locknut height is replaced by a smaller bolt head (other means could be used to provide thread locking i.e. LOCTITE, nylon patch, or the like) and the stud anchored over the ball joint is now located adjacent to it. This scheme produces the desired effect of greatly reducing the vertical height required and the while providing an adjustment range of between about 1.75 to 4.25 degrees. 
     FIG. 9 shows the suspension of FIG. 1 wherein wheel angle (especially camber) adjusting apparatus  120  has been added to translate the upper ball joint ( 18  in FIG. 1) a distance “Y”, either inward towards the vehicle frame, or outward away from the vehicle frame. As before, this modification could also apply to the lower ball joint  19 . 
     Details of the construction of adjusting apparatus  120  are shown in FIGS. 10 through 15. Insert  122  (alike in many respects except as noted herein to insert  23  described hereinabove) and ball joint retaining module  124  are secured utilizing threaded stud, or bolt,  126  (preferably having a low profile head  127 ) extending through elongated slot  128  in insert  122 . 
     FIG. 15 shows an exploded view of the camber adjusting apparatus as it is installed in its environment. Insert  122  is pressed into upper control arm  10  (or lower control arm  12  in some cases) in place of the factory supplied ball joint and is oriented, for example, along the neutral caster angle by means of a dimple or similar orientation mark  130  on the control arm and a corresponding dimple or other orientation mark  132  on insert  122 . Ball joint module  124  includes body  134  oriented to match slot  128  of insert  122  by virtue of linear orientation guide slots  136  (see FIG. 10) defined at an upper surface thereof. Ball joint module  124  also includes ball joint  138  pressed into cavity  140  in body  134  having a seating rim  141  next to a through opening. Protective cover  142  is installed in the same cavity  140  and includes a portion of guide slots  136  thereat. 
     A threaded bore  144  overlaps cavity  140  in body  134  (and is also in part defined at an upper segment of ball joint  138  and at cover  142 ) and accepts the threaded end of bolt  126 . Orientation guide pins  146  or similar protrusions are press fit into openings in (or similarly attached to or defined at) the bottom surface of insert  122  and are positioned to mate with the guide slots  136  to maintain component alignment. The entire apparatus is held together by bolt  126  which is placed and positioned through the elongated slot  128  of insert  122 , engaged at threaded bore  144  of body  124  and tightened. The ball joint ( 138 ) is conventionally attached to spindle  14  as described hereinabove. 
     Camber angle corrections can be obtained by installing adjusting apparatus  120  at either upper control arm  10  or lower control arm  12 . The adjusting apparatus can be moved inward, towards the vehicle frame, or outward, away from the vehicle frame, by moving bolt  126  in insert slot  128  until the correct camber angle is achieved. The position of the adjustment is then secured by applying sufficient torque to bolt  126 . 
     Apparatus  120  is installed by pressing the existing ball joint is out of the upper control arm  10 . Insert  122  is then pressed into the top of the upper control arm with the orientation marks on the insert and control arm aligned (for camber only adjustment). Ball joint is placed into the counter bored hole  140  of body  134  with its notch aligned over threaded bore  144  in body  134  and is fully pressed in place. Cover  142  is then installed (press fit, for example) over the ball joint with the portions of guide slots  136  in both cover  142  and body  134  aligned. Orientation guide pins  146  are pressed into holes at insert  122  to the proper depth. 
     Module  124  is placed on the opposite side (below) the control arm so that pins  146  fit into guide slots  136  and bolt  126  (with LOCTITE added) is inserted through insert slot  128  to threaded bore  144 . The stud of ball joint  138  is then attached to the wheel spindle. 
     It may become desirable to correct a mis-aligned vehicle with other than strictly camber correction. A geometric relationship exists between the upper and lower wheel spindle connections (ball joints) and the camber and caster angles of the wheel to the vehicle. As previously indicated, altering the position of one of the ball joints in the neutral caster direction affects the camber angle in a desirable fashion. Extending this to caster and camber/caster combination directions, the camber adjusting apparatus can be used to adjust caster only angles or some combination of camber and caster. 
     If other than strictly camber corrections are desired, the angular azimuth orientation between the orientation mark  130  on the upper control arm  10  or lower control arm  12  and orientation mark  132  on insert  122  can be modified after first determining the amount of camber and/or caster angle correction required using standard geometric calculation. The amount of camber an/or caster angle needed will determine the azimuth orientation of insert  122  and hence the entire apparatus. Once the correction is known, orientation mark  132  is aligned, with a template or some other means, relative to orientation mark  130  and insert  122  is pressed into upper arm control  10  or lower control arm  12 . Bolt  126  is set to the proper position in insert slot  128  and tightened to maintain the setting. 
     Accordingly, it can be seen that the adjustable camber apparatus  120  will restore the factory specified camber and/or caster angle to the tire and wheel or set the camber and/or caster angle to another desired value, while utilizing a minimal amount of space. The adjustable camber apparatus could be installed so as to affect caster angle only or a combination of camber and caster angle.