Wheel alignment arrangements for vehicles

Control arms used to support a swivel member retaining a wheel of a vehicle are attached to the body or frame rail of the vehicle by U-shaped attachment brackets having walls with lateral slots therein, each of which receives a mounting bolt therethrough. The mounting bolts pass through bushings in the ends of the control arms to pivot the control arms on the vehicle body or frame rail. Adjacent to the heads of the bolts are pairs of reaction surfaces that in one embodiment of the invention are pairs of opposed projecting surfaces on the attachment brackets. Separate tools are provided which have cams thereon each having a first peripheral cam surface for engaging one of the reaction surfaces and a second peripheral cam surface for engaging the other reaction surface. Upon loosening nuts threaded on the mounting bolts and rotating the cams with levers, socket wrench handles or other drives, the bolts shift laterally in the lateral slots enabling adjustment of the camber and caster of the wheels. In another embodiment, the reaction surfaces are opposite sides of a pin projecting from one of the flanges and the cam is a curved slot within a cam portion of the tool.

FIELD OF THE INVENTION

The present invention is directed to wheel alignment arrangements for motor vehicles. More particularly, the present invention is directed to wheel alignment arrangements for motor vehicles that provide for adjustments in control arm positions in order to select desired camber and caster settings.

BACKGROUND OF THE INVENTION

In most situations, motor vehicles having steerable wheels support wheel axles on swivel members which are retained between upper and lower control arms (also known as A-arms or wishbones). The upper and lower control arms have front and rear legs that are pivotally mounted on the body or frame rails of the vehicle. Disposed between the lower control arms and body or frame of the vehicles are shock absorbers that include springs and dampers.

Steerable wheels of automotive vehicles require adjustment in camber and caster in order to maintain proper alignment. Camber is the amount that wheels are closer to one another at the bottom than at the top and caster is the slight backward tilt of wheels.

According to current practice, camber and caster are adjusted by alignment cams which are integral with couplings that attach the control arms to a vehicle's body or frame. Deletion of these alignment cams could reduce weight, space consumption and expense. Since there is a continuing need to make automotive components less massive, costly and intrusive, elimination of these integral alignment cams may be desirable.

SUMMARY OF THE INVENTION

In view of the aforementioned considerations, an alignment arrangement is provided for adjusting alignment of a vehicle wheel, wherein the alignment arrangement supports on a vehicle body or frame, inboard ends of a control arm, and includes a device comprising a pair of bushings and bracket structures which cooperate with at least one removable tool. Each bushing extends through one of the inboard ends of the control arm and has an opening therethrough which receives a mounting bolt. Each of the bracket structures are fixed with respect to the body or frame of the vehicle and are each defined by first and second opposed walls. The first and second opposed walls each have lateral slots therein receiving therethrough opposite ends of one of the mounting bolts. At least one of the walls has reaction surfaces thereon disposed adjacent to the slot therein. At least one removable tool includes a cam portion for engagement with the reaction surfaces on the brackets. This cam portion has a fixed axis of rotation with respect to the bolts on the brackets for shifting the bolts in the lateral slots upon rotation of the removable tool.

In accordance with a first embodiment of the invention, the reaction surfaces comprise a pair of opposed surfaces extending from one of the walls. When the cam portion of the tool is disposed between the reaction surfaces and rotated in a first direction, the bolt and control arm move away from the body or frame rail to adjust alignment of the wheel, and when the tool is rotated in a second direction, the bolt and control arm move toward the body or frame to adjust alignment of the wheel.

In accordance with a second embodiment of the invention, the reaction surfaces are provided by a projection extending from a wall of the bracket structure, the cam portion being a curved slot in a rotatable body driven by a lever or power tool, which curved slot receives the projection.

In a third embodiment of the invention, a first reaction surface is formed on a flange which is welded to a body or frame rail of the vehicle and the second reaction surface is on a deflected portion of one wall.

In a fourth embodiment of the invention the tool comprises a gear with an axial opening that is non-rotationally mounted on the head of the bolt when the tool is applied to the bolt. The cam portion of the tool comprises a pair of cooperating racks disposed between the reaction surfaces, each rack having a row of teeth facing the gear and an oppositely facing surface facing one of the reaction surfaces.

In preferred embodiment for the tool, the cam portion of the tool has a coupling thereon aligned with the axis of the bolt, the coupling cooperating with a stud of a wrench handle or a power tool.

In another aspect of the invention, the control arm is an upper control arm of a vehicle suspension having upper and lower control arms.

In still another aspect of the invention, the control arm is a lower control arm of a vehicle suspension having upper and lower control arms.

DETAILED DESCRIPTION

FIG. 1shows a prior art suspension arrangement10for supporting a hub and bearing assembly11, which includes an axle that mounts a wheel12of an automotive vehicle. The arrangement10utilizes upper and lower control arms13and14, respectively, which have pairs of mounting bushings15and16, respectively. Integral with the lower mounting bushings16on the lower control arm14are alignment cams17. In accordance with the prior art arrangement10, there are two alignment cams17for each wheel12, resulting in four cams per automotive vehicle, which results in additional weight of about 1.5 lbs per vehicle. In the prior art configuration ofFIG. 1, the upper mounting bushings15of the upper control arm13do not have adjustment cams17, but are pivoted on bow tie connections18. In other prior art configurations, not shown, alignment cams17are on the upper control arm13rather than the lower control arm14. Generally, vehicles such as trucks have alignment cams on the upper control arms13while passenger vehicles tend to have alignment cams on the lower control arms14.

Referring now toFIG. 2, there is shown an alignment arrangement20, according to a first embodiment of the present invention, for supporting the hub and bearing assembly11that includes an axle mounting the front wheel12of the motor vehicle. While the present invention has application to the front wheels of vehicles, it is also useful for other wheels, such rear wheels, which may also be independently sprung and which in some vehicles are steerable. Generally, the alignment arrangement20is incorporated in a suspension system which comprises a swivel member24having a short arm to which a steering rod is attached. The swivel member24has upper and lower swivel joints28and29to which upper and lower control arms30and32are attached by swivel pins34and36, respectively. A shock absorber38, including a coil spring (not shown) and hydraulic damper extends between the lower wishbone32and body or frame rail39of the vehicle.

The upper control arm30has first and second legs40and42having a common outboard end44that receives the swivel pin34and inboard ends46and48, respectively, that are pivoted to the vehicle body39by bow tie or tee joints49and50cooperating with bushing housings51and52. The lower control arm32includes first and second legs54and56that are pivoted by bushing housings58and60to the body39or frame rail39′ of the vehicle at inboard ends63and64of the lower control arm by similar camless alignment couplings65and65′, configured in accordance with a first embodiment of the present invention.

The camless alignment couplings65and65′ do not have the alignment cams17ofFIG. 1. Each camless alignment coupling65and65′ includes a U-shaped control arm bracket66having projecting walls67and68, which have laterally extending slots70and72therein that receive mounting bolts74having heads75and nuts76. The U-shaped control arm brackets66for each of the camless alignment coupling65and65′ are substantially the same for each of the bushing housings58and60of the control arm32. In the embodiment ofFIG. 2separate control arm brackets66are shown. While separate control arm brackets66are preferred, in an alternative arrangement the walls67and68are within indentations in the body39or frame rails39′, which walls “bracket” the bushing housings58and60by retaining the bushing housings therebetween.

Referring now toFIG. 3, the bushing housings58and60are substantially the same, each having a circular opening80therethrough that receives a bushing81. The bushing81fits tightly within the circular opening80and includes a resilient portion83made of rubber, or a similar elastic material, which resilient portion83is integral with a metal sleeve84that serves as a bearing for a smooth shank portion86of the mounting bolt74. The mounting bolt74has a threaded end87on which the nut76is threaded. The nut76abuts a washer89positioned over the lateral slot72, while the head75of the mounting bolt74abuts a washer90that is positioned over the lateral slot70. In accordance with a preferred aspect of the invention the washers provide bearing surfaces against the walls67and68. In accordance with another embodiment, not preferred, the bearing surfaces against the walls67and68are directly on the head75of the bolt74and on the nut76.

The combination of the mounting bolts74with the slots70and72and the walls67and68provides an inexpensive and reliable, camless mounting arrangement that does not need integral cams, such as the alignment cams17ofFIG. 1, mounted therewith. In addition to not having integral alignment cams17, the mounting bolts74used in the arrangement ofFIGS. 2–5are standard, unsplined bolts instead of being relatively expensive splined bolts used in the prior art arrangement ofFIG. 1. The absence of alignment cams17from the camless alignment couplings65and65′ results in savings in assembly labor and reductions in plant inventory. The absence of alignment cams17ofFIG. 1also results in saving in mass (according to one example about 1.2 lbs. per vehicle), which when combined with other savings in mass contribute to an accumulated reduction in weight for the entire vehicle. In addition, since at least the integral alignment cams17on the prior art lower control arm14ofFIG. 1tend to project beyond the bushing housings16into space adjacent to the bushing housings, there is a reduction in space consumption proximate the lower bushing housings58and60of the present invention.

FIG. 4illustrates the first embodiment of the present invention in combination with a pair of removable tools79and79′ shown in dotted lines. The removable tool79is used to adjust the position of leg54of control arm32with respect to camless alignment bracket65, while the tool79′ is used to adjust the position of leg56with respect to camless alignment bracket65′. Preferably, during assembly of the vehicle both tools79and79′ are employed on the bolts74of the respective camless brackets65and65′. The tools79and79′ are rotated in the same direction in order to adjust camber of the front wheel12and in opposite directions to adjust castor of the front wheel by driving cam portions of the tools against reaction surfaces, as explained hereinafter.

As is seen inFIG. 4, in the absence of integral alignment cams17, lateral adjustment of the position of bushing housings50and52with respect to the body39or frame rail39′ is accomplished by using the tools79and79′ configured as separate cam wrenches. The tools79and79′ each have a projecting handle95and a cam portion96with a hexagonal opening97therein that receives the hexagonal head75of one of the mounting bolts74.

As is seen inFIG. 5where only one of the tools79is shown in operation, it is seen that the cam portion96has a first peripheral cam surface98and a second peripheral cam surface99. The first peripheral cam surface98engages a first reaction surface100which extends from the wall67, while the second peripheral cam surface99engages a second reaction surface102that also extends from the wall67. The reaction surfaces100and102are opposed surfaces which face one another. The handle95of the tool79and the cam portion96rotate about the axis104of the mounting bolt74. This causes the first peripheral cam surface98to advance against the first reaction surface100on the flange67when the cam head96is rotated clockwise.

The second peripheral cam surface99advances against the second reaction surface102when the cam portion96is rotated counterclockwise. Since the mounting bolt74is free to shift laterally in the slot70as the cam head96rotates, and since the reaction surfaces100and102on the bracket66are fixed with respect to the body39(or frame rails39′) of the vehicle, the mounting bolt74necessarily shifts the control arm32toward the body or frame rail39when the first peripheral cam surface98is rotated to press against the reaction surface100. The mounting bolt74also necessarily shifts the leg54of the control arm32away from the body or frame rail39and39′ when the second peripheral cam surface99is rotated to press against the second reaction surface102.

The tool79′ is used to adjust the leg56of the control arm32by the bolt74associated with the camless alignment bracket65′ in a manner substantially identical to the use of the tool79to adjust the leg54of the control arm32.

When proper alignment is achieved, the nuts76on the mounting bolts74are tightened to retain the mounting bolts and thus the lower control arm32in the desired position with respect to the slots70and72, and thus in the desired position with respect to the body39or frame rail39′ of the vehicle.

Since the cam96is an integral or unitary part of the tool79, separate alignment cams17are not carried by the suspension system20, therefore the mass and consumption of space by the cams is eliminated from the vehicle. Moreover, the need to store alignment cams17in vehicle inventory is eliminated.

Referring now toFIGS. 6–8there is shown a second embodiment of the invention wherein reaction surfaces100′ and102′ are on opposite sides of a projection, such as a pin110. The pin110is received in a curved cam slot112disposed in a cam head96′ that is rotated by the handle95′ of a tool79a.The cam slot112has a first cam surface98′ and a second cam surface99′ that push against the reaction surfaces100′ and102′. Note that the cam surfaces98′ and99′ appear reversed inFIGS. 6 and 7with respect toFIGS. 3–5, however this is because the cam surface98′ pushes the mounting bolt74to the left in the lateral slot70′, as seen inFIG. 6, while the cam surface99pushes the bolt74to the right in the lateral slot70′ toward the body39, as seen inFIG. 7.FIG. 8shows the attachment bracket66′ used with the control arm32and a separate tool79a,which is used to adjust the lateral position of the mounting bolts74in the slots70and72. The embodiment ofFIGS. 6–8is a pin-in-slot reacted embodiment rather than an edge reacted embodiment such as that ofFIGS. 2–5.

Referring now toFIGS. 9-12a third embodiment of the invention is shown wherein a suspension system200includes a swivel joint210pivoted on an upper control arm230and a lower control arm232. In the third embodiment, the upper control arm230has a pair of bushing housings236and238that are pivoted to a pair of camless control arm brackets240and242, configured in accordance with the present invention to provide an alignment arrangement, and welded to a frame rail244. The lower control arm232is attached to the frame rail244with non-adjustable couplings such as the non-adjustable couplings provided by the bowtie connections18ofFIGS. 1 and 2. The suspension system200is a preferred configuration for trucks.

The suspension system200is illustrated inFIGS. 9-12as used for steerable front wheels, however the principles and structure of the suspension system200are applicable to rear wheels as well, steerable or unsteerable.

The camless control arm brackets240and242are U-shaped and preferably identical to one another, with the bracket240being a front bracket and bracket242being a rear bracket. Each of the brackets240and242has a top flange250for welding to the top surface of the frame rail244and a pair of side flanges252for welding to the inside surface of the frame rail. Each of the brackets240and242also have outer side walls256and258, that have lateral slots260and262, respectively therein. Bolts266, each having a head268and a threaded end270, pass through the lateral slots260, through the bushing housings256and258and through the lateral slots262. Nuts272are threaded onto the ends270of the bolts266to tightly retain the bolts266in fixed lateral positions in lateral slots260and262when tightened. The bushing housings236and238each have the structure shown inFIG. 3and include a bushing with a resilient portion having an integral metal sleeve that receives a smooth shank portion of the bolt266.

Referring now toFIGS. 10–12it is seen that at least one of the walls256and258has a first reaction surface280and a second reaction surface282. The second reaction surface282is on the flange252which is welded to an inside surface of the frame rail244. As is seen inFIGS. 10 and 11the first reaction surface280is formed by deflecting a knotched portion283of the wall256out of the plane of the wall. The embodiment ofFIG. 12has similarities toFIGS. 10 and 11, but inFIG. 12the first reaction surface280′ is on a turnover flange283′ rather than being adjacent to a knotch portion.

A tool290having a cam portion291with peripheral cam surfaces292and293has a socket294formed in a collar295that receives either the head268of the bolt266or the nut272. InFIG. 11, the nut272is received in the socket294, however the head268may also be received in the socket in the manner shown inFIGS. 3–5. The socket294of the tool290has a lug receiving portion296which is substantially square in cross section that receives a lug297of a socket wrench298to retain and drive the cam portion291of the tool290. The socket wrench298has a handle299. As with the suspension system20ofFIG. 4, the suspension system200ofFIG. 9uses a pair of detachable tools290to adjust camber and castor of the wheel supported by the suspension system by shifting the bolts266laterally in the slots260and262.

Referring now toFIGS. 13 and 14where a fourth embodiment of the invention is shown, the control arm bracket66for the control arms are the same as inFIGS. 2–5, however the tool300has another configuration wherein a pair of cams340and342interact with the first and second reaction surfaces100and102. The cam34has a plurality of roller bearings344facing the first reaction surface100, while the cam342has a plurality of roller bearings346facing the second reaction surface102. The cams340and342are attached to a gear350that has peripheral teeth352that engage complementary teeth354and356on the cams340and342, respectively. The cams340and342are linked to the gear350by links360and362that have pin-in-slot connections364and366with the cams. The gear350has a hub368which has a hexagonal socket portion369complementing the bolt head75and a square socket portion370therein to receive a lug of a ratchet wrench or power tool (not shown). When the gear350rotates in a clockwise direction, the gear teeth352on the gear engage the gear teeth354on the cam340to lift the cam and thus press the cam against the reaction surface100. Simultaneously, the cam342is lowered so that the mounting bolt74and the control arm40are moved toward the reaction surface102, and thus toward the body39or frame rail39′. This causes the mounting bolt74, engaged by the hexagonal socket portion of the tool300to shift to the left and move away from the vehicle body39or frame rail39′ as the mounting bolt slides axially in the slots70and72. Rotation of the gear350in the counterclockwise direction causes the bearings346of the second cam342to press against the second reaction surface102. This shifts the mounting bolt74away from the second reaction surface102, and thus away from the body39or frame rail39′ of the vehicle.

From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing form the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.