Irrigation tire

1. A non-directional pneumatic tire for supporting an agricultural irrigation system, comprising:

first and second sidewalls and a radially outer wall defining an internal inflation chamber;

a non-directional tread pattern defined on the tire and including a plurality of longitudinal protrusions positioned substantially parallel to a rotational axis of the tire;

the longitudinal protrusions being arranged in a first row extending from the first sidewall toward and across an equatorial plane of the tire and a second row extending from the second sidewall toward and across the equatorial plane of the tire, the longitudinal protrusions of the first and second rows circumferentially alternating with each other and there being a circumferential spacing between adjacent longitudinal protrusions at the equatorial plane so that no portion of one longitudinal protrusion circumferentially coincides with another;

each longitudinal protrusion of the first row including a contact surface, each of the contact surfaces of the first row increasing in circumferential width from the first sidewall toward the equatorial plane of the tire and then circumferentially eccentrically tapering to a rounded end; and

each longitudinal protrusion of the second row including a contact surface, each of the contact surfaces of the second row increasing in circumferential width from the second sidewall toward the equatorial plane of the tire and then circumferentially eccentrically tapering to a rounded end.

2. The tire of claim 1 , wherein:

the contact surface of each longitudinal protrusion continuously increases in circumferential width all the way from its respective sidewall to the equatorial plane of the tire.

3. The tire of claim 1 , wherein:

the contact surface of each longitudinal protrusion has substantially straight edges between its respective sidewall and the equatorial plane of the tire.

4. The tire of claim 1 , wherein:

the eccentrically tapered end of each longitudinal protrusion begins substantially at the equatorial plane of the tire.

5. A non-directional pneumatic tire for supporting an agricultural irrigation system, comprising:

first and second sidewalls and a radially outer wall defining an internal inflation chamber;

a non-directional tread pattern defined on the tire and including a plurality of longitudinal protrusions positioned substantially parallel to a rotational axis of the tire;

the longitudinal protrusions being arranged in a first row extending from the first sidewall toward and across an equatorial plane of the tire and a second row extending from the second sidewall toward and across the equatorial plane of the tire, the longitudinal protrusions of the first and second rows circumferentially alternating with each other and there being a circumferential spacing between adjacent longitudinal protrusions at the equatorial plane so that no portion of one longitudinal protrusion circumferentially coincides with another;

each longitudinal protrusion of the first row including a contact surface, each of the contact surfaces of the first row increasing in circumferential width from the first sidewall toward the equatorial plane of the tire and then circumferentially eccentrically tapering to a rounded end; and

each longitudinal protrusion of the second row including a contact surface, each of the contact surfaces of the second row increasing in circumferential width from the second sidewall toward the equatorial plane of the tire and then circumferentially eccentrically tapering to a rounded end; and

wherein the eccentrically tapered ends of the longitudinal protrusions of the first row are eccentrically tapered circumferentially in an opposite direction from the eccentrically tapered ends of the longitudinal protrusions of the second row.

6. A non-directional pneumatic tire for supporting an agricultural irrigation system, comprising:

first and second sidewalls and a radially outer wall defining an internal inflation chamber;

a non-directional tread pattern defined on the tire and including a plurality of longitudinal protrusions positioned substantially parallel to a rotational axis of the tire, each longitudinal protrusion having a terminal end with a circumferentially asymmetrically enlarged head; and

the longitudinal protrusions being arranged in a first row extending from the first sidewall toward and across an equatorial plane of the tire and a second row extending from the second sidewall toward and across the equatorial plane of the tire, the longitudinal protrusions of the first and second rows circumferentially alternating with each other and there being a circumferential spacing between adjacent longitudinal protrusions at the equatorial plane so that no portion of one longitudinal protrusion circumferentially coincides with another;

wherein the enlarged heads of the longitudinal protrusions of the first row face circumferentially in an opposite direction from the enlarged heads of the longitudinal protrusions of the second row;

wherein each longitudinal protrusion includes a contact surface that increases in circumferential width from its respective sidewall toward the equatorial plane of the tire and then circumferentially eccentrically tapers to a rounded end.

7. The tire of claim 6 , wherein the tread pattern has a relatively low rubber to void ratio over a tire width of less than about 20%.

8. The tire of claim 6 , wherein the tread pattern has a rubber to void ratio over a tire width in the range of from about 16% to about 20%.

9. The tire of claim 6 , wherein an aspect ratio of the tire defined as tire section height divided by tire section width is no greater than about 90%, thereby providing a relatively wide tire.

10. The tire of claim 6 , having a tire section width of at least 10 inches.

11. The tire of claim 10 , having an outside diameter of at least 40 inches.

12. The tire of claim 6 , having a tread pitch in the range of 10 to 25, the tread pitch being defined as the number of longitudinal protrusions in one of said first and second rows.

13. The tire of claim 12 , wherein the tread pitch is in the range of 15 to 21.

14. The tire of claim 12 , wherein an outside diameter of the tire is at least about 40 inches.

15. The tire of claim 6 , wherein the tire comprises rubber and an anti-weathering agent, the anti-weathering agent comprising at least 8 parts per hundred parts of the rubber.

16. The tire of claim 15 , wherein the anti-weathering agent comprises 8-18 parts per hundred parts of the rubber.

17. The tire of claim 15 , wherein the anti-weathering agent is selected from the group consisting of wax, an anti oxidant, resin, an anti ozonant and combinations thereof.

18. The tire of claim 6 , wherein:

the tread pattern further includes a circumferential protrusion spanning the equatorial plane, the enlarged head of each of the longitudinal protrusions overlying the circumferential protrusion.

19. The tire of claim 6 , wherein:

the contact surface of each longitudinal protrusion continuously increases in circumferential width all the way from its respective sidewall to the equatorial plane of the tire.

20. The tire of claim 19 , wherein:

the eccentrically tapered end of each longitudinal protrusion begins substantially at the equatorial plane.

21. The tire of claim 6 , wherein:

the contact surface of each longitudinal protrusion has substantially straight edges between its respective sidewall and the equatorial plane of the tire.