Digital turn plate apparatus

• US 6,047,594 A
• Filed: 05/22/1997
• Issued: 04/11/2000
• Est. Priority Date: 05/23/1996
• Status: Expired due to Term

• Current Assignee: Intercomp Company
• Original Assignee: Intercomp Company
• Inventors: Rhoe, Bruce G., Kroll, William P., Kroll, Karl J. F.
• Primary Examiner(s): MCCALL, ERIC SCOTT
• Application Number:
  US08/861,883
• Time in Patent Office: 1,055 Days
• Field of Search: 73/11.04, 73/865.9, 73/122, 73/124, 73/127, 33/203.12, 33/203.14, 33/203.16, 33/203.18, 33/203.19
• US Class Current: 73/122
• CPC Class Codes: G01B 5/255 for testing wheel alignment
• CPC Class Codes: G01B 7/315 for testing wheel alignment

Abstract

A digital turn plate apparatus for aligning steering systems of wheeled devices. The turn plate apparatus has a rotational degree of motion for determining the angle of wheel alignment. The turn plate apparatus also has lateral and longitudinal degrees of motion to accommodate the lateral and longitudinal motion of the bottom of tires which can occur during turning or when the suspension is compressed. The turn plate apparatus generally includes a base, a top plate, a handle plate, a lower middle plate, a potentiometer, and a digital display mechanism. The top plate is rotatably mounted to the handle plate and is functionally engaged with the potentiometer. The turn plate apparatus digitally displays the rotational position of the top plate to within a tenth of a degree. The handle plate is constructed to have a longitudinal degree of motion with respect to the base and the lower middle plate is constructed to have a lateral degree of motion with respect to the base.

Claims

1. A turn plate apparatus, comprising:

(a) a base;

(b) a top plate;

(c) means for rotatably mounting said top plate to said base, said top plate having a plurality of rotational positions with respect to said base;

(d) means for detecting the rotational position of said top plate;

(e) means for displaying a detected rotational position of said top plate, and

(f) a handle plate disposed between said top plate and said base, said means for rotatabley mounting said top plate to said base including means for rotatably mounting said top plate to said handle plate and means for longitudinally mounting said handle plate to said base, whereby said top plate has rotational and longitudinal degrees of motion with respect to said base.

2. The turn plate apparatus of claim 1, wherein said means for displaying a detected rotational position of said top plate includes a digital display mechanism electrically integrated with said means for detecting the rotational position of said top plate.

3. The turn plate apparatus of claim 2, wherein each of said plurality of rotational positions has an angle of displacement, and said means for detecting the rotational position of said top plate includes means for measuring said angle of displacement.

4. The turn plate apparatus of claim 3, wherein said digital display mechanism includes a reset button designed to calibrate said angle of displacement and said display mechanism to zero degrees at any of said plurality of rotational positions of said top plate with respect to said base.

5. The turn plate apparatus of claim 3, wherein said means for measuring said angle of displacement comprises:

(a) a potentiometer having variable resistance;

(b) rotatable means for varying the resistance of said potentiometer;

(c) means for functionally engaging said top plate to said rotatable means for varying the resistance of said potentiometer;

(d) an electrical power supply; and

(e) a control circuit electrically connected to said power supply and said potentiometer, whereby said control circuit calculates the resistance of said potentiometer by creating and measuring an electrical potential across said potentiometer and converts the measured resistance of said potentiometer into the detected rotational position of said top plate.

6. The turn plate apparatus of claim 5, wherein said electrical power supply comprises a battery.

7. The turn plate apparatus of claim 5, wherein:

(a) said rotatable means for varying the resistance of said potentiometer includes a rotatable potentiometer shaft extending from said potentiometer; and

(b) said means for functionally engaging said top plate to said rotatable means for varying the resistance of said potentiometer includes a potentiometer shaft stop fixedly attached to said potentiometer shaft and a potentiometer shaft stop groove sized and positioned in said top plate to functionally receive said potentiometer shaft stop.

8. The turn plate apparatus of claim 1, further comprising:

(a) an upper bearing retainer disposed beneath said top plate, said upper bearing retainer having a plurality of bearing apertures; and

(b) a plurality of bearings seated within said bearing apertures, said bearings being in functional contact with said top plate to assist with a smooth rotation of said top plate.

9. The turn plate apparatus of claim 8, wherein said plurality of bearings includes a plurality of roller bearings and said bearing apertures are arranged radially and are sized to receive said plurality of roller bearings.

10. The turn plate apparatus of claim 9, wherein said plurality of bearing apertures includes a plurality of long apertures, a plurality of intermediate apertures, and a plurality of short apertures arranged to optimize radial spacing of said bearing apertures and said roller bearings in said upper bearing retainer.

11. The turn plate apparatus of claim 1, wherein said handle plate has one or more handle apertures.

12. The turn plate apparatus of claim 1, wherein said means for rotatably mounting said top plate to said handle plate includes a coupling mechanism.

13. The turn plate apparatus of claim 12, wherein said coupling mechanism comprises:

(a) a lower ring retainer fixedly attached to said handle plate, said lower ring retainer having an outer periphery and a lip around said outer periphery; and

(b) an upper ring retainer fixedly attached to said top plate, said upper ring retainer having an inner periphery and a lip around said inner periphery;

whereby said lower ring retainer is concentrically seated within said upper ring retainer and the lip of said lower ring retainer securely engages the lip of said upper ring retainer and rotatably couples said top plate to said handle plate.

14. The turn plate apparatus of claim 13, wherein said lower ring retainer, said upper ring retainer, and said handle plate have a potentiometer aperture sized to receive a potentiometer.

15. The turn plate apparatus of claim 1, further comprising:

(a) a middle bearing retainer disposed beneath said handle plate, said middle bearing retainer having a plurality of bearing apertures; and

(b) a plurality of bearings seated within said bearing apertures, said bearings being in functional contact with said handle plate to assist with a smooth motion of said handle plate.

16. The turn plate apparatus of claim 15, wherein said plurality of bearings includes a plurality of roller bearings and said plurality of bearing apertures are sized to receive said roller bearings and are arranged to provide smooth longitudinal motion of said handle plate.

17. The turn plate apparatus of claim 11, further comprising a lower middle plate disposed between said middle bearing retainer and said base, said means for longitudinally mounting said handle plate to said base includes means for longitudinally mounting said handle plate to said lower middle plate and means for laterally mounting said lower middle plate to said base, whereby said top plate has rotational, longitudinal, and lateral degrees of motion with respect to said base.

18. The turn plate apparatus of claim 17, further comprising:

(a) a lower bearing retainer disposed beneath said lower middle plate, said lower bearing retainer having a plurality of bearing apertures; and

(b) a plurality of bearings seated within said bearing slots, said bearings being in functional contact with said lower middle plate to assist with a smooth motion of said lower middle plate.

19. The turn plate apparatus of claim 18, wherein said plurality of bearings includes a plurality of roller bearings and said plurality of bearing apertures are sized to receive said roller bearings and are arranged to provide smooth lateral motion of said handle plate.

20. The turn plate apparatus of claim 17, further comprising a plurality of retractable hitch pins, wherein said top plate, said handle plate, said lower middle plate, and said base have a plurality of hitch pin apertures sized and arranged to receive said hitch pins and lock said top plate, said handle plate, said lower middle plate, and said base together.

21. A digital turn plate apparatus for use in aligning steering systems, comprising:

(a) a base;

(b) a lower bearing retainer disposed on said base, said lower bearing retainer having a plurality of lower bearing apertures;

(c) a plurality of lower bearings seated within said lower bearing apertures;

(d) a lower middle plate disposed on said lower bearings and secured to said base, said lower middle plate having a stable, lateral motion with respect to said base;

(e) a middle bearing retainer disposed on said lower middle plate, said middle bearing retainer having a plurality of middle bearing slots;

(f) a plurality of middle bearings seated within said middle bearing apertures;

(g) a handle plate disposed on said middle bearings and secured to said lower middle plate, said handle plate having a stable, longitudinal motion with respect to said base;

(h) an upper bearing retainer disposed on said handle plate, said upper bearing retainer having a plurality of upper bearing apertures;

(i) a plurality of upper bearings seated within said upper bearing apertures of said upper bearing retainer;

(j) a top plate disposed on said upper bearings and rotatably secured to said handle plate, said top plate having a stable, rotational motion with respect to said base;

(k) a potentiometer having variable resistance;

(l) a potentiometer shaft extending from said potentiometer, said potentiometer shaft being capable of rotatably varying the resistance of said potentiometer;

(m) a potentiometer shaft stop fixedly attached to said potentiometer shaft;

(n) a potentiometer shaft stop groove sized and positioned in said top plate to functionally receive said shaft stop;

(o) an electrical power supply;

(p) a control circuit electrically connected to said power supply and said potentiometer, wherein said control circuit calculates the resistance of said potentiometer by creating and measuring an electrical potential across said potentiometer and converts the measured resistance into a detected rotational position of said top plate; and

(q) a digital display mechanism electrically integrated with said control circuit and designed to display the detected rotational position of said top plate, whereby said top plate has a rotational degree of motion and can be used to adjust tire alignment, and said handle plate has a longitudinal degree of motion and said lower middle plate has a lateral degree of motion to allow a tire that is being aligned to remain generally centered on said top plate during testing.

22. A turn plate apparatus, comprising:

(a) a base;

(b) a top plate having rotational and linear degrees of motion with respect to said base, said linear degrees of motion including lateral and longitudinal degrees of motion;

(c) a first middle plate disposed between said top plate and said base;

(d) means for laterally and longitudinally mounting said first middle plate to said base;

(e) means for rotatably mounting said top plate to said first middle plate wherein said first middle plate isolates said rotational degree of motion of said top plate with respect to said base from said linear degrees of motion of said top plate with respect to said base;

(f) means for detecting the rotational position of said top plate; and

(g) means for displaying a detected rotational position of said top plate.

23. The turn plate apparatus of claim 22, wherein said means for detecting the rotational position of said top plate includes a potentiometer having variable resistance operably connected between said top plate and said first middle plate, and wherein rotating said top plate with respect to said first middle plate varies the resistance of said potentiometer.

24. The turn plate apparatus of claim 22, further comprising a second middle plate disposed between said first middle plate and said base, wherein said means for laterally and longitudinally mounting said first middle plate to said base includes means for longitudinally mounting said first middle plate to said second middle plate and means for laterally mounting said second middle plate to said base.

25. The turn plate apparatus of claim 24, wherein said means for longitudinally mounting said first middle plate to said second middle plate includes a plurality of roller bearings, a plurality of fasteners, and a bearing retainer and said means for laterally mounting said second middle plate to said base includes a plurality of roller bearings, a plurality of fasteners, and a bearing retainer, each of said bearing retainers having a plurality of parallel roller bearing slots in which said roller bearings are seated and a plurality of parallel fastener slots through which said fasteners extend, said fastener slots being perpendicular to said roller bearing slots and being adapted for guiding and limiting linear motion.