Wheel alignment method and apparatus

• US 3,897,636 A
• Filed: 11/14/1973
• Issued: 08/05/1975
• Est. Priority Date: 11/14/1973
• Status: Expired due to Term

• Current Assignee: Joseph V. Leblanc
• Original Assignee: Joseph V. Leblanc
• Inventors: Leblanc, Joseph V.
• Primary Examiner(s): Martin, Jr., William D.
• Application Number:
  US05/415,518
• Time in Patent Office: 629 Days
• Field of Search: 33/203,203.12,203.13,203.14 73/117
• US Class Current: 33/203.13
• CPC Class Codes: G01B 7/315 for testing wheel alignment

Abstract

In one exemplar embodiment, a wheel alignment apparatus is provided for aligning the front wheels of a motor vehicle to have a parallel track while rotating the wheels at an rpm equivalent to normal highway speed. The motor vehicle is oriented on a ramp on a horizontal surface. Means are provided for indicating any difference in the relative caster of the front wheels and the caster is then adjusted to a common value. The wheels are placed in contact with a pair of spaced drums mounted for rotation on a drive shaft and adapted for limited lateral movement. Means are provided for securing the motor vehicle in a fixed position with the axis of the front wheels vertically aligned over the drum drive shaft. The drums are rotated to drive the wheels at a normal highway speed and a force measuring means interconnecting the spaced drums detects side thrust forces exerted on the spaced drums by the rotating wheels for indicating any divergence from parallel of the track of the front wheels. The track of the front wheels can then be adjusted until the force measuring means indicates that the track is parallel, under dynamic conditions approximating normal highway driving speeds.

Claims

1. A method for paralleling the track of the front wheels of a motor vehicle at highway speeds, comprising the steps of orienting the motor vehicle on a horizontal surface, placing the front wheels of the motor vehicle in contact with a pair of spaced drums adapted for common limited lateral movement on a drive shaft, said drums adapted for common lateral movement by means of a non-extensible connecting means holding said drums in a spaced relationship, adjusting the caster of the front wheels to a common value, aligning the axis of the front wheels vertically over the axis of said drive shaft, rotating said spaced pair of drums together on said drive shaft for driving the front wheels at an rpm equal to average highway speed, determining any condition of divergence of the track of the front wheels from a parallel relationship at said highway speed by determining the tension or compression forces exerted on said connecting means by said spaced drums as a result of side thrust forces excited by said wheels at said highway speed, and adjusting the relative track of the front wheels to a parallel relationship while the wheels are rotating at said highway speed.

2. Apparatus for determining any condition of divergence of the track of the front wheels of a motor vehicle from a parallel relationship at highway speeds, comprising ramp means for orienting the motor vehicle on a horizontal surface, pointer means for indicating any difference in the relative caster of the front wheels of the motor vehicle, a pair of spaced drums mounted for rotation on a drive shaft and adapted for common lateral movement along said drive shaft, means for securing the motor vehicle in a fixed position with the front wheels in contact with said spaced drums, said means being adjustable to vertically orient the axis of the wheels with the axis of said drive shaft, drive means for rotating said drive shaft and said spaced pair of drums for driving the front wheels at an rpm equal to average highway speed, connecting means disposed between said spaced drums for retaining said drums in a spaced relationship during rotation and providing for common lateral movement of said drums, and detecting means cooperating with said connecting means for detecting tension or compression forces in said connecting means as a result of side thrust forces exerted on said spaced drums by the wheels being rotated at said highway speed for determining any divergence from parallel of the track of the front wheels.

3. The apparatus as described in claim 2, wherein said drive means comprises a pulley attached to said drive shaft, a variable speed electric motor, a gear box attached to the output shaft of said electric motor, said gear box having an output shaft and a drive pulley mounted thereon, and a drive belt interconnecting said gear box drive pulley and the pulley attached to said drum drive shaft.

4. The apparatus as described in claim 2, wherein said connecting means comprises a pair of spaced sleeves encircling said drive shaft and attached to said spaced drums for rotating therewith, a pair of spaced brackets each journaled on one of said sleeves for allowing the sleeve to rotate within said bracket, and at least one bar interconnecting said spaced brackets and adapted for holding said brackets fixed with relation to said rotating sleeves and maintaining said drums in a spaced relationship.

5. The apparatus as described in claim 4, wherein said detecting means comprises force measuring means attached to said at Least one bar for detecting tension or compression forces in said bar resulting from any side thrust forces exerted on said rotating spaced drums by said wheels, and indicating means connected to said force measuring means for indicating the presence of said tension or compression forces in said bar for indicating divergence from parallel of the track of the front wheels while traveling at highway speed.

6. The apparatus as described in claim 5, wherein said indicating means comprises a gauge indicator for indicating the pressure of compression or tension forces measured by said force measuring means.

7. The apparatus as described in claim 2, wherein said pointer means for indicating any difference in the relative caster of the front wheels of the motor vehicle comprises a pair of spaced, vertically extensible indicators oriented in the vertical plane passing through said drum drive shaft and located on opposite sides of said motor vehicle for alignment with the axis of the axle of each of the front wheels, any misalignment of one of the indicators with its respective wheel axle indicating a difference in relative caster of the front wheels.

8. The apparatus as described in claim 2, wherein said spaced drums are mounted for rotation on said drive shaft and adapted for lateral movement along the drive shaft by a combination ball bearing key and race means comprising a plurality of slots axially disposed along the surface of said drive shaft, a plurality of axial slots and cylindrical bores disposed in drive shaft accommodating hubs of said drums, said axial slots and bores radially spaced for communication with respective ones of said axial slots in said drive shaft, and a plurality of ball bearings disposed in said communicating axial slots of said drum hubs and said drive shaft and said cylindrical bore for acting as a key in said communicating slots of said hub and drive shaft for locking said drum hub in relation to said drive shaft during rotation but permitting said ball bearings to circulate through said aligned axial slots of said drum hub and said drive shaft and said communicating circular bore for permitting lateral movement of said drum axially along said drive shaft.

9. Apparatus for determining any condition of divergence of the track of the front wheels of a motor vehicle from a parallel relationship at highway speeds, comprising ramp means for orienting the motor vehicle on a horizontal surface, pointer means for indicating any difference in the relative caster of the front wheels of the motor vehicle, a pair of spaced drums mounted for rotation on a drive shaft and adapted for common lateral movement along said drive shaft, means for securing the motor vehicle in a fixed position with the front wheels in contact with said spaced drums, said means being adjustable to vertically orient the axis of the wheels with the axis of said drive shaft, drive means for rotating said drive shaft and said spaced pair of drums for driving the front wheels at an rpm equal to average highway speed, a pair of spaced sleeves encircling said drive shaft and attached to said spaced drums for rotating therewith, a pair of spaced brackets each journaled on one of said sleeves for allowing the sleeve to rotate within said bracket, at least one bar interconnecting said spaced brackets and adapted for holding said brackets fixed with relation to said rotating sleeves and maintaining said drums in a spaced relationship, force measuring means attached to said at least one bar for detecting tension or compression forces in said bar resulting from any side thrust forces exerted on said rotating spaced drums by said wheels, and indicating means connected to said force measuring means for indicating the presence of said tension or compression forces in said bar for indicating divergence from parallel of the track of the front wheels while traveling at highway speed.

10. The apparatus as described in claim 9, wherein said drive means comprises a pulley attached to said drive shaft, a variable speed electric motor, a gear box attached to the output shaft of said electric motor, said gear box having an output shaft and a drive pulley mounted thereon, and a drive belt interconnecting said gear box drive pulley and the pulley attached to said drum drive shaft.

11. The apparatus as described in claim 9, wherein said indicating means comprises a gauge indicator for indicating the pressure of compression or tension forces measured by said force measuring means.

12. The apparatus as described in claim 9, wherein said pointer means for indicating any difference in the relative caster of the front wheels of the motor vehicle comprises a pair of spaced, vertically extensible indicators oriented in the vertical plane passing through said drum drive shaft and located on opposite sides of said motor vehicle for alignment with the axis of the axle of each of the front wheels, any misalignment of one of the indicators with its respective wheel axle indicating a difference in relative caster of the front wheels.

13. The apparatus as described in claim 9, wherein said spaced drums are mounted for rotation on said drive shaft and adapted for lateral movement along the drive shaft by a combination ball bearing key and race means comprising a plurality of slots axially disposed along the surface of said drive shaft, a plurality of axial slots and cylindrical bores disposed in drive shaft accommodating hubs of said drums, said axial slots and bores radially spaced for communication with respective ones of said axial slots in said drive shaft, and a plurality of ball bearings disposed in said communicating axial slots of said drum hubs and said drive shaft and said cylindrical bore for acting as a key in said communicating slots of said hub and drive shaft for locking said drum hub in relation to said drive shaft during rotation but permitting said ball bearings to circulate through said aligned axial slots of said drum hub and said drive shaft and said communicating circular bore for permitting lateral movement of said drum axially along said drive shaft.