Abstract: A wheel balancer is provided that includes a shaft adapted for receiving a wheel/tire assembly, the shaft having a longitudinal axis and being rotatable about the axis so as to rotate a wheel/tire assembly removably mounted thereon, a rotation sensor assembly for measuring rotation of the shaft about its longitudinal axis, a vibration sensor assembly operatively connected to the shaft for measuring vibration resulting from imbalance in the wheel/tire assembly, a motor operably connected to the shaft for rotating the shaft about its longitudinal axis, a load roller for applying force to the wheel/tire assembly during rotation thereof. A control circuit is also included for controlling the force applied by the load roller to the wheel/tire assembly during rotation. The control circuit causes the load roller to vary the force applied by the load roller to the wheel/tire assembly.

Abstract: A wheel balancer is provided that includes a shaft adapted for receiving a wheel/tire assembly, the shaft having a longitudinal axis and being rotatable about the axis so as to rotate a wheel/tire assembly removably mounted thereon, a rotation sensor assembly for measuring rotation of the shaft about its longitudinal axis, a vibration sensor assembly for measuring vibration of the wheel/tire assembly as the wheel/tire assembly is rotated, a motor operably connected to the shaft for rotating the shaft about its longitudinal axis, a load roller for applying a generally radial force to the wheel/tire assembly during rotation of the wheel/tire assembly and a sensor for measuring the runout of the wheel rim of the wheel/tire assembly at the bead seat.

Abstract: A wheel balancer is provided that includes a shaft adapted for receiving a wheel/tire assembly, the shaft having a longitudinal axis and being rotatable about the axis so as to rotate a wheel/tire assembly removably mounted thereon, a rotation sensor for measuring rotation of the shaft about its longitudinal axis, a vibration sensor operatively connected to the shaft for measuring vibrations resulting from imbalance in the wheel/tire assembly and a motor operatively connected to the shaft for rotating the shaft about its longitudinal axis, thereby to rotate the wheel/tire assembly. A control circuit is also provided for controlling the application of power to the motor. The wheel balancer also includes an assembly for measuring runout of the rim of the wheel/tire assembly, the control circuit being responsive to a rim runout measurement signal to apply power to the motor such that the wheel/tire assembly rotates at a slow, controlled speed during measurement of the rim runout.

Abstract: A wheel balancer is provided that includes a shaft adapted for receiving a wheel/tire assembly, the shaft having a longitudinal axis and being rotatable about the axis so as to rotate a wheel/tire assembly removably mounted thereon. The wheel balancer also includes a rotation sensor for measuring the rotation of the shaft about its longitudinal axis, vibration sensor operatively connected to the shaft for measuring vibrations resulting from imbalance in the wheel/tire assembly and a motor operatively connected the shaft for rotating the shaft about its longitudinal axis, thereby rotating the wheel/tire assembly. A control circuit for controlling the application of power to the motor is also included. The control circuit controls the application of power to the motor to rotate the wheel/tire assembly and to actively hold the wheel/tire assembly at desired positions.

Abstract: A wheel balancer is provided that includes a shaft adapted for receiving a wheel/tire assembly, the shaft having a longitudinal axis and being rotatable about the axis so as to rotate a wheel/tire assembly removably mounted thereon, a rotation sensor for measuring rotation of the shaft about its longitudinal axis and a vibration sensor operatively connected to the shaft for measuring vibrations resulting from imbalance in the wheel/tire assembly. A motor operatively connected to the shaft for rotating the shaft about its longitudinal axis to rotate the wheel/tire assembly is also included. The wheel balancer further includes a control circuit for controlling the application of current to the motor to rotate the wheel/tire assembly at a plurality of sustainable speeds. The control circuit may also be adapted for determining from vibrations measured by the vibration sensor at least one weight placement position on the wheel/tire assembly to correct the vibrations.

Abstract: A wheel balancer has a shaft for receiving a wheel/tire assembly, a rotation sensor assembly for measuring rotation of the shaft about its longitudinal axis, a motor operatively connected to the shaft for rotating said shaft about its longitudinal axis, thereby to rotate the wheel/tire assembly, a vibration sensor assembly for measuring vibration of the wheel/tire assembly as the wheel/tire assembly is rotated, and a load roller for applying a generally radial force to the wheel/tire assembly during rotation of said wheel/tire assembly. Movement of the load roller is measured to determine loaded radial runout of the wheel/tire assembly while the force is applied thereto and a a tire stiffness value for the wheel/tire assembly is provided.

Abstract: A wheel balancer has an improved drive circuit and improved safety features. The drive circuit includes an H-bridge configuration, preferably utilizing MOSFET or IGBT transistors. The safety features include an electrical brake which operates upon removal of power to safely and reliably stop the rotation of the wheel/tire assembly being balanced. A hardware safety interlock is provided to limit rpm and/or travel of the wheel/tire assembly based upon preset criteria. A novel display system is included for displaying axial, radial, and/or loaded runout of the wheel/tire assembly.

Abstract: Apparatus and method for determining the alignment positions and orientations of vehicle wheels includes optical targets mounted on the wheels. A pair of cameras or other image sensing devices on each side of the vehicle are used to obtain images of the various optical targets and a computer is responsive to the images of the targets to determine values of wheel alignment parameters of the vehicle. The surface on which the wheels are disposed may be an automotive lift or a stationary runway. One camera on each side is directed at the target on the corresponding front wheel and the other camera on each side is directed at the target on the corresponding rear wheel. When used with a rack, the major axis of the field of view of each camera is disposed vertically. When used with a stationary runway, the major axis of the field of view of each camera is disposed horizontally.

Abstract: A wheel balancing system for the reduction of vehicle wheel and pneumatic tire assembly vibrations with the capacity to determine and selectively adjust the pneumatic tire's pressure simultaneously with wheel balancing. The balancing system includes a drive for rotating the tire and wheel assembly; a sensing system for the selective determination of vibration causation and correction information; a pneumatic system for the adjustment of the pneumatic tire's pressure; a control system for instituting the determined vibration corrections and pressure adjustments; as well as a communication system for receiving, transmitting and presenting data or instructions. The sensing system is responsive to the wheel balancing systems operational status, the wheel and tire assembly's operational status, wireless or network communications and input from the user. The control system includes automatic provisions for safety, convenience, time efficiency, balancing and pressure adjustment.

Abstract: Apparatus and method for determining the alignment of a wheel of a vehicle includes mounting a known optical target to a wheel on the vehicle, the known optical target having a plurality of optical elements, each optical element having at least one straight edge disposed on a background, obtaining at least one video image of the optical target, estimating from the video image of the optical target the characteristics in said video image of a plurality of lines corresponding to projections onto the video image of the straight edges of the optical elements, and determining from the estimates of the characteristics the alignment of the wheel. A similar target for determining the position of a runway on which the vehicle is positioned is also disclosed.

Abstract: A system for measuring vehicle alignment angles has a plurality of sensor elements for mounting to wheels of a vehicle to be aligned. The system uses the sensor elements to measure various angles such as steer ahead angle and toe, and the system also has a display for displaying information to a user and a memory for storing operating instructions for the system. Operating instructions are stored in the memory for determining from compensation measurements taken at a minimum of first and second longitudinally displaced positions whether the toe parameter of two wheels falls outside a predetermined toe range, and whether the steer ahead angle of the vehicle falls within a predetermined range. The operating instructions stored in the memory further include instructions responsive to the toe parameter falling outside the toe range to control the system to display to the user information indicative of the need to adjust the toe parameter before taking additional compensation measurements.

Abstract: Steering wheel lash and suspension play are checked by comparing predefined movements of the steering wheel and the road wheels. A steering wheel fixture adapted to be mounted to the steering wheel particularly facilitates the steering wheel lash determination. Quickly mountable and removable road wheel angle sensors also facilitate the method.

Abstract: Apparatus and method for determining the alignment of a wheel of a vehicle includes mounting a known optical target to a wheel on the vehicle, the known optical target having a plurality of optical elements, each optical element having at least one straight edge disposed on a background, obtaining at least one video image of the optical target, estimating from the video image of the optical target the characteristics in said video image of a plurality of lines corresponding to projections onto the video image of the straight edges of the optical elements, and determining from the estimates of the characteristics the alignment of the wheel. A similar target for determining the position of a runway on which the vehicle is positioned is also disclosed.

Abstract: A vehicle alignment and inspection system is provided which uses context sensitive information from several sources to enable the user/operator to achieve a more efficient alignment or inspection than previous systems. Features include digital photographs responsive to point-and-click operations by the operator, drop-down menus allowing direct access to specific operations, a database of tools and parts required for the job, and a "smart" alignment procedure.

Abstract: The system includes camber and toe sensing apparatus, a memory for storing camber and toe specifications for a plurality of vehicles, and a computer. The computer compares sensed camber and toe with corresponding specification of camber and toe, selects a shim from a plurality of standard shims and a shim orientation to attempt to correct both camber and toe in accordance with a preset priority, and determines residual camber error and residual toe error that would result from installation of the shim at the selected orientation. The user may select another orientation that attempts to correct both camber and toe in accordance with the manually requested desired priority. The user works with the system interactively, and can request various error priorities or allocation on the fly. The residual errors resulting from the selected priorities are displayed in substantially real time to provide visual feedback.

Abstract: A vehicle wheel alignment apparatus includes wheel alignment sensors for obtaining wheel alignment data, including camber, and devices for measuring wheel offset distances. A controller compensates the measured wheel offset distances for the camber of the corresponding wheels. Ride height sensors are included for measuring the ride height of the vehicle at the wheels, and the controller also uses the ride height to compensate the wheel offset distances. Ride height is similarly compensated for camber by the controller. The body angle of the vehicle is obtained from the wheel offset measurements and the wheelbase of the vehicle. The body angle is used to compute dog track angles and correct those angles by applying the body angle to the individual toe angles of the reference axle. Axle offsets are computed and used in front axle cradle adjustment if applicable. The body angle is also used to eliminate the effect of wheel offsets from setback angle calculations.

Abstract: Vehicle wheel alignment apparatus includes a storage device for storing vehicle wheel alignment angle specifications, wheel alignment sensors, and ride height sensors. A controller is responsive to the acquired wheel alignment angle data and to the measured ride height for determining whether, taking into consideration the vehicle ride height, a measured wheel alignment angle falls within specifications. Apparatus for diagnosing vehicle wheel alignment and suspension problems also includes a jack for vertically moving the body of the vehicle with respect to the wheels to temporarily change the ride height of the vehicle. The controller is responsive to changes in measured wheel alignment angles with changes in measured ride height to diagnose vehicle alignment and suspension problems.

Abstract: A sideslip tester detects sideslip and scrub in a vehicle having a steering axle and one or more pairs of tandem axles. The sideslip tester has a runway having a measurement plate which is moved laterally with respect to its longitudinal axis as a tire of the vehicle passes over the measurement plate as a result of lateral forces acting upon the tire. A lateral movement sensor operatively connected to the measurement plate determines the amount of lateral movement of the measurement plate as the vehicle tire passes over the plate and provides an output corresponding to the amount of lateral movement measured. The sideslip tester can determine when it is presented with tandem axles. When it is presented with tandem axles, the sideslip tester will determine the scrub angle of the tandem axles to determine if they are parallel.

Abstract: The brakes of a two-axle vehicle are tested by weighing the vehicle and measuring the braking forces for both axles to determine the actual ratio of front axle braking force to total braking force. The deceleration applied to the vehicle is determined from the weight of the vehicle and the applied braking forces. A nominal preferred value of the ratio of front axle braking force to total braking force is calculated from the determined deceleration and the measured weight of the vehicle. The nominal preferred value varies from test to test with both the actual deceleration and the vehicle weight. For each test, upper and lower limits for the acceptability of the actual ratio of front axle braking force to total braking force are set based upon the computed nominal preferred value. These limits move from test to test with the computed nominal preferred value. The nominal preferred value, the movable limits, and the actual ratio are displayed to the user on a CRT screen.

Abstract: A plate brake tester for testing the adequacy of the brakes of a vehicle, particularly suited for testing the brakes of multi-axle vehicles, includes weight bearing plates suitably sized to receive thereon wheel/tire assemblies of a vehicle as the vehicle is driven over the plates. The plates have sensors associated therewith for sensing not only the brake force applied by each wheel/tire assembly, but also for directly sensing the dynamic weight of the wheel/tire assembly on each plate during braking. The adequacy of the brakes is determined from the brake force and the directly sensed dynamic weight. At least some of the sensors are preferably dual axis load cells, each dual axis load cell having one output representing vertical force applied to that plate and having a second output representing horizontal force applied to that plate, the horizontal force being the braking force from the wheel/tire assembly disposed on that plate.