Wheel alignment system with ball joint wear monitor and method

• US 4,574,490 A
• Filed: 02/07/1985
• Issued: 03/11/1986
• Est. Priority Date: 04/13/1984
• Status: Expired due to Fees

• Current Assignee: Dynabal Corporation
• Original Assignee: Dynabal Corporation
• Inventors: Curchod, Donald B.
• Primary Examiner(s): Little, Willis
• Application Number:
  US06/699,357
• Time in Patent Office: 397 Days
• Field of Search: 33/203.18, 33/203, 33/203.15, 33/203.16, 33/203.19, 33/180 AT, 33/288, 33/203.14, 33/203.19
• US Class Current: 33/203.18
• CPC Class Codes: G01B 11/275 for testing wheel alignment
• CPC Class Codes: G01B 2210/26 Algorithms, instructions, databases, computerized methods and graphical user interfaces employed by a user in conjunction with the wheel aligner
• CPC Class Codes: G01B 2210/283 Beam projectors and related sensors
• CPC Class Codes: G01B 7/144 Measuring play on bearings
• CPC Class Codes: G01B 7/315 for testing wheel alignment

Abstract

A wheel alignment and ball joint wear monitoring system employs a diagrammatic pictorial video display of the chassis of the vehicle being aligned and pictorial diagrams of alignment parameters associated with each of the wheels of the chassis. The region of each wheel when separately enlarged carries a chassis diagram indicating which wheel portion of the diagram has been enlarged. The system permits successive measurements of camber and of toe to be used to determine ball joint wear in the vertical and horizontal planes.

Claims

1. In a wheel alignment system for a vehicle of a type having a laterally spaced pair of steerable wheels and a laterally spaced pair of unsteerable wheels generally following the steerable wheels, said system including means for displaying on a screen a diagrammatic pictorial representation of the vehicle chassis including all four wheels and a plurality of pictorial diagrams shown in immediate association with each said wheel to respectively display pictorially the status of a corresponding plurality of alignment parameters for each wheel, the last named means displaying an indicator disposed in association with each pictorial diagram for a given wheel, each of said indicators being movable between and beyond upper and lower limits indicated on the screen to show diagrammatically the status of a wheel alignment parameter to be within proper limits or not, said limits being defined to correspond to the vehicle alignment specifications, means for sensing the status of the wheel alignment parameters, and means controlling the analog position of each of said indicators with respect to the limits associated therewith and in response to adjustments made to a wheel associated with the indicator, the last named means displaying digital values associated with the lower and upper limits and of the status of the parameter which is sensed.

2. In a wheel alignment system according to claim 1 in which said means for sensing said wheel alignment parameters includes a sensor assembly comprising a sensor support housing adapted to be carried by a wheel in a manner permitting the wheel to rotate independently of said housing, fixed and movable transparent panels disposed in closely spaced superimposed relation, means supporting said movable panel to rotate in opposite directions from a zero angle position for measuring angles to each side of said position, said panels being polarized at substantially 45°

to each other when disposed at said zero angle relation to partially inhibit passage of light therethrough and serving to cause a reduction in transmissivity when rotated in one direction and an increase when rotated in an opposite direction, a first and second photosensor of a type providing an output signal which varies in response to the amount of light applied to it, said sensors being disposed on a common side of said panels and a light source disposed on the other, one of said photosensors being disposed to receive light transmitted directly to it from said light source uninhibited by said panels to establish a standard for comparison, the other photosensor being disposed to detect light transmitted from said light source via said panels, and means for comparing the output signals from both said sensors to provide a signal indicative of the angle displaced from the zero angle position of said movable panel.

3. Means for sensing wheel alignment parameters including a sensor assembly comprising a sensor support housing to be carried by a wheel in a manner permitting the wheel to rotate independently of said housing, fixed and movable transparent panels disposed in closely spaced superimposed relation, means supporting said movable panel to rotate in opposite directions from a zero angle position for measuring angles to each side of said position, said panels being polarized and substantially 45°

to each other when disposed at said zero angle relation to partially inhibit passage of light therethrough and serving to cause a reduction in transmissivity when rotated in one direction and an increase when rotated in an opposite direction, a first and second photosensor of a type providing an output signal which varies in response to the amount of light applied to it, said sensors being disposed on a common side of said panels and a light source disposed on the other, one of said photosensors being disposed to receive light transmitted directly to it from said light source uninhibited by said panels to establish a standard for comparison, the other photosensor being disposed to detect light transmitted from said light source via said panels, and means for comparing the output signals from both said sensors to provide a signal indicative of the angle displaced from the zero angle position of said movable panel.

4. In a sensor assembly according to claim 3 further including a second light source disposed to transmit light directly to both said sensors to provide output signals from each, switch means serving to independently connect one or the other of said light sources to power to either detect angles to be sensed or to detect a difference between the output signals from both said sensors generated by a common light source to determine the accuracy of the relationship between the two sensors.

5. In a system for aligning the wheels of a vehicle comprising a sensor assembly for detecting angles of toe, camber, caster and providing output signals associated with each indicative of the value of each, gating means coupled to receive said output signals, analog to digital conversion means coupled to receive signals from said gating means, data storage means having a portion for receiving and storing the values of said angles, a microcomputer interposed between said storage means and said analog to digital conversion means and coupled to control said gating means for transmitting said output signals to said storage means, said data storage means having a second portion for storing the alignment specifications of substantially all automobiles and trucks, microprocessor means coupled to both said portions of said storage means, and a cartridge receiving controller including a keyboard coupled to said microprocessor for controlling said display to pictorially present said alignment parameters and the status of each.

6. In a wheel alignment system for aligning the wheels of a vehicle of a type having a chassis, a laterally spaced pair of steerable wheels and a laterally spaced pair of unsteerable wheels generally following the steerable wheels, said system including means for displaying on a screen a diagrammatic pictorial representation of a wheel in a plurality of pictorial diagrams, said diagrams respectively displaying pictorially the status of each of a corresponding plurality of alignment parameters for said wheel, said diagrams including spaced markers representative of the upper and lower limits of proper adjustment of a given alignment parameter for the wheel according to the manufacturer'"'"'s specifications, an indicator disposed in association with each pictorial diagram to move between and beyond said markers on the screen to show diagrammatically the status of a wheel alignment parameter to be within or beyond proper limits, and means controlling the analog position of each of said indicators with respect to the limits associated therewith in response to the status of and adjustments made to the wheel parameter associated with the indicator.

7. In a wheel alignment system according to claim 6 further comprising means for displaying digital values adjacent to said markers and indicators and representative of said limits and said status.

8. In a wheel alignment system for aligning the wheels of a vehicle of a type having a chassis, a laterally spaced pair of steerable wheels and a laterally spaced pair of unsteerable wheels generally following the steerable wheels, said system including means for displaying on a screen a diagrammatic pictorial representation of a given wheel in a plurality of pictorial diagrams, said diagrams respectively displaying pictorially the status of each of a corresponding plurality of alignment parameters for said wheel, said diagrams including means representative of the upper and lower limits of proper adjustment of a given alignment parameter for the wheel according to the manufacturer'"'"'s specifications, means disposed in association with each pictorial diagram for indicating the status of a wheel alignment parameter to be within or beyond proper limits, and means controlling the last named said means in response to the status of and adjustments made to the wheel parameter.

9. In a wheel alignment system according to claim 8 in which said means representative of the limits include means for displaying digital values adjacent to and representative of said limits.

10. In a wheel alignment system according to claim 8 in which said means for indicating the status of a wheel alignment parameter includes means for displaying digital values representative of said status.

11. In a wheel alignment system according to claim 8 in which said means representative of the limits comprises spaced markers, and wherein said means for indicating the status of a wheel alignment parameter includes an indicator movable between and beyond said markers to show diagrammatically the status of a wheel alignment parameter to be within or beyond proper limits.

12. In a wheel alignment system according to claim 11 wherein said means for indicating the status of a wheel alignment parameter further includes means for displaying the approximate digital value thereof adjacent to said movable indicator.

13. In a wheel alignment system according to claim 12 wherein said means representative of the limits includes means for displaying digital values representative of said limits.

14. In a system for aligning the wheels of a vehicle and for detecting and measuring ball joint wear, said system comprising a sensor assembly for detecting angles of alignment parameters including camber and toe and providing output signals associated with each indicative of first and second values of each of said parameters for a given wheel, said sensor assembly being adapted to be carried by a wheel of the vehicle, said first and second values of camber being provided respectively when the top of the wheel is urged toward the vehicle and when urged away from the vehicle, said first and second values of toe being provided with the steering wheel locked against rotation and when the leading part of the wheel is respectively urged toward the vehicle and urged away from the vehicle, means coupled to said sensor assembly for storing said first and second values of each said parameter, means for comparing said first and second values of each parameter for a wheel to measure the difference therebetween and provide first and second difference signals representative of the degree of ball joint wear in vertical and horizontal planes, the difference between said camber values, being representative of the vertical error in the ball joint and the difference between said toe values being representative of the horizontal error, means for displaying a diagrammatic pictorial representation of the vehicle chassis and a pictorial diagram shown in immediate association with a wheel thereof indicative of the vertical and horizontal error in its associated ball joints, and means coupling the last named means to receive said difference signals to provide said pictorial diagrams on said display means.

15. The method of measuring ball joint wear in a steerable wheel of a vehicle of a type having a steering wheel comprising the steps of restraining the steering wheel against rotation, measuring camber of said wheel while applying forces attempting to tilt the plane of the wheel toward the vehicle from the top of the wheel, measuring camber of said wheel while reversing said forces, storing the first and second named camber measurements, measuring toe of said wheel while applying forces attempting to steer the wheel to one side, measuring toe of said wheel applying reverse forces attempting to steer the wheel to the other side, storing the first and second named toe measurements, comparing the camber measurements to determine the ball joint wear in a vertical plane, comparing the toe measurements to provide information representative of ball joint wear in a horizontal plane, displaying a diagrammatic representation of a vehicle chassis including its wheels and a plurality of pictorial diagrams in immediate association with the steerable wheels of said chassis to pictorially show the status of ball joint wear for said steerable wheels.

16. In a system for aligning the wheels of a vehicle characterized by means for detecting and displaying the degree of ball joint wear for a given one of the wheels, said system comprising a sensor assembly adapted to be carried by a wheel of the vehicle to provide output signals representing the status of the alignment parameters of camber and toe for the wheel, means for comparing two successive output signals for the same rotational position of the wheel, said successive signals being with respect to and representative of the velue of one of said parameters to determine the difference between said successive signals, one of said signals being sensed while force is applied to said wheel tending to twist the plane of the wheel in one direction, the other of said signals being sensed while force is applied in an opposite direction, and means for pictorially displaying said difference in a manner representing the degree of ball joint wear associated with said one parameter.

17. In a system for aligning the wheels of a vehicle characterized by means for detecting ball joint wear, said system comprising sensor assemblies adapted to be carried by each of a plurality of steerable wheels of the vehicle to provide output signals representing the value of the alignment parameter of toe for each steerable wheel, means for continuously comparing said output signals during left and right steering movements of said steerable wheels to monitor the difference between said output signals representative of left and right toe, means for detecting change in said difference, means for converting said change to information representative of an angle, and means for supplying said information to a display of a type for displaying said angle.

18. In a wheel alignment system having means for sensing the status of wheel alignment parameters and for generating signals representative thereof, a video display coupled to the last-named means for providing a pictorial diagram thereon of a vehicle chassis indicating four wheels and pictorial representations of the status of wheel alignment parameters associated with each said wheel, means for displaying an enlarged portion of said diagram including the representation of one wheel and said alignment parameters associated therewith, part of the enlarged display including a diagrammatic representation of a four-wheel chassis with three of the four wheel positions having a common appearance different from the appearance of the fourth wheel position of said diagrammatic representation so as to identify the fourth wheel as being represented by the enlarged portion of the display.