Method and apparatus for determining tire quality

• US 3,927,561 A
• Filed: 05/09/1974
• Issued: 12/23/1975
• Est. Priority Date: 05/22/1973
• Status: Expired due to Term

• Current Assignee: Peter Schleimann
• Original Assignee: Peter Schleimann
• Inventors: Schleimann, Peter
• Primary Examiner(s): Woodiel, Donald O.
• Application Number:
  US05/468,581
• Time in Patent Office: 593 Days
• Field of Search: 73/146,8
• US Class Current: 73/146
• CPC Class Codes: G01M 17/022 the tyre co-operating with rotatable rolls

Abstract

A method and apparatus for testing tire quality in which a tire is mounted for rotation about the periphery of a test drum and the lateral, radial and tangential forces detected. The electrical signals produced by the pick-ups are applied to an analyzing circuit to calculate moments and provide an indication of tire quality.

Claims

1. A method of determining the quality of tires, with regard to nonuniformities of the tire structure, comprising:

measuring the forces generated during the rotation of the tire, and measuring at least the radial and total lateral moments in the footprint area of the tire which result from the tangential, radial and lateral forces acting on each other and/or offset from the wheel center plane.

2. A method according to claim 1 wherein said step of measuring moment includes measuring the developing tangential and/or radial force couples and at least the lateral force.

3. A method according to claim 1 wherein said step of measuring moment includes measuring the couple Of the radial forces and the lateral force.

4. A method according to claim 1 wherein said step of measuring moment includes measuring the couple of tangential forces to determine the total moment acting in the plane of the footprint area.

5. Device for producing an indication of tire quality comprising:

a test drum having a roll-off surface for rotatably engaging the tire to be tested, a plurality of force pick-ups to measure the magnitude of the forces originating from the rotating tire, two pick-ups each mounted for measuring the tangential and radial forces and at least one pick-up mounted for the lateral forces, and an analysing circuit connected to send pick-ups for producing an output indicating the quality including means for producing an indication of the total lateral moment and means for producing an indication of radial moment.

6. Device according to claim 5, wherein the pickups are disposed to sense the axle of the test drum.

7. Device according to claim 5, wherein the pickups are disposed to sense the axle of the tire to be tested.

8. Device according to claim 5, wherein said analysing circuit includes a first difference calculator to which the outputs of the two pick-ups for radial forces are applied, and a further difference calculator to which the outputs of the first difference calculator and of the pick-up for the lateral forces are applied, so that the output of the first difference calculator is amplified depending on the distance between the wheel center plane and the pick-up for the lateral forces is amplified depending on the test drum diameter and the wheel diameter respectively.

9. Device according to claim 5, wherein the output of the pick-up for the lateral forces is in addition connected to an indicating system for the lateral forces.

10. Device according to claim 5, wherein said the analysing circuit includes a further integrator to which the outputs of the two pick-ups for the radial forces are connected.

11. Device according to claim 5, wherein said the analysing circuit includes a further difference calculator to which the outputs of the pick-ups for the tangential forces are connected, and wherein the output of the differentiator is amplified by a factor depending on the distance between the pick-ups and the wheel center plane.