Environmental tire

• US 5,027,876 A
• Filed: 11/13/1989
• Issued: 07/02/1991
• Est. Priority Date: 11/13/1989
• Status: Expired due to Fees

• Current Assignee: Goodyear Tire & Rubber Company
• Original Assignee: Goodyear Tire & Rubber Company
• Inventors: White, John T., Chrobak, Dennis S.
• Primary Examiner(s): Ball, Michael W.
• Assistant Examiner(s): OSELE, MARK A
• Application Number:
  US07/434,664
• Time in Patent Office: 596 Days
• Field of Search: 152/209 R, 152/454, 152/560
• US Class Current: 152/209.14
• CPC Class Codes: B60C 11/032 Patterns comprising isolated recesses
• CPC Class Codes: B60C 13/003 characterised by sidewall curvature
• CPC Class Codes: B60C 3/04 characterised by the relative dimensions of the section, e.g. low profile B60C3/06 takes precedence

Abstract

A low pressure radial ply tire (20) for light off-the-road use has tow radial carcass plies (22) oriented at a cord angle (CA) with respect to the Equatorial Plane (EP) from 65 to 85°. The tire is not reinforced by a belt reinforcing structure to allow the carcass (22) to compensate within the footprint of the tire under varying conditions. The tread (26) is provided with a number of holes (38) having a very shallow depth and spaced uniformly across the tread surface to increase flotation and wherein the net-to-gross is in the range of 0.63 to 0.77.

Claims

1. A low pressure pneumatic non-belt reinforced radial ply tire for light off-the-road use comprising

a circumferentially extending ground engaging tread portion, formed by a radius of 8 to 10 times the section height of the tire, said tread portion having a plurality of voids spaced about said tread such that the net-to-gross is in the range of 0.63 to 0.77;

a pair of sidewalls, one said sidewall extending radially inward from each lateral edge of said tread to a bead portion having an inextensible bead therein;

two radial carcass plies, each extending from one said bead to the other said bead portion, said carcass plies comprising a plurality of cords laid at a cord angle from 65°

to 85°

with respect to the equatorial plane;

wherein the tire has rounded shoulders formed by a radius of 34% 42% of the section height of the tire, and the aspect ratio of the tire is in the range of 0.40 to 0.75; and

wherein the tire at rated load and inflation pressure has a unit tread pressure of less than 15.75 psi.

2. The tire according to claim 1 wherein the voids have a diameter from 1.8% to 4% of the section height of the tire.

3. The tire according to claim 2 wherein the depth of said voids is from 12% to 15% of the diameter of the void.

4. The tire according to claim 3 wherein said cord angle is from 65°

to 75°

.

5. The tire according to claim 4 wherein said cord angle is about 65°

-70°

.

6. The tire according to claim 4 wherein the voids are dimples.

7. The tire according to claim 4 wherein the voids are hexagonal.

8. The tire according to claim 4 wherein the tire has a substantially constant number of voids per unit tread area.

9. The tire according to claim 4 wherein the depth of the voids is from 0.36% to 0.6% of the maximum section height of the tire.