Patent ID: 6062282
Filing Date: 2000-05-16
Classification: B60C

Abstract:
A pneumatic agricultural tire having a maximum section width (SW), an axis of rotation, an equatorial plane centered between the maximum section width and perpendicular to the axis, a casing having a carcass reinforced with rubber coated cords, a rubber tread disposed radially outwardly of the casing, the tread having a first and a second lateral tread edge, the distance between the lateral tread edges defining the tread width (TW), the tread has an inner tread and a plurality of tread lugs projecting radially from the inner tread, all the tread lugs having a length (l.sub.1) and a width (l.sub.w) the ratio of lug length (l.sub.1) to lug width (l.sub.w) being at least 3:1, the tread being characterized by:a plurality of shoulder lugs, the plurality of shoulder lugs being divided into a first row and a second row of shoulder lugs extending from each first and second lateral edges respectively toward the equatorial plane, the lugs of the first row being circumferentially offset relative to the lugs of the second row;a plurality of central lugs oriented in the same direction and arranged in a row and each central lug extending across the equatorial plane, each lug having a lug height (l.sub.h), the ratio of the shoulder lug width (l.sub.w) to shoulder lug height (l.sub.h) being less than 2/3 over at least 70% of the shoulder lug length (l.sub.l);wherein the lugs of the first row of shoulder lugs are substantially aligned with the central lugs along their respective lug lengths and the shoulder lugs of the second row are oppositely oriented relative to the first row of shoulder lugs, the combination of shoulder lugs and central lugs forming an asymmetric chevron pattern having a point of the chevron pattern located between the equatorial plane and the second lateral edge, a primary leg of the chevron pattern lying along the substantially aligned lengths of the shoulder lugs of the first row and the central lugs, and a secondary leg of the chevron pattern lying along the length of the shoulder lugs of the second row and the point of the chevron pattern;wherein the tread has a net-to-gross ratio less than 35% and each leg of the chevron pattern creates soil discharge channels extending outward through the lateral edges, the soil discharge channels extending outward through the first lateral edge being substantially larger than the soil discharge channels extending outward through the second lateral edge, the central lugs spaced a minimum distance of 1.5 times the central lug width (l.sub.w) from an adjacent central lug such that the central lugs do not overlap in the circumferential direction.