A wheel assembly includes a rigid wheel and an airless flexible tire with certain performance characteristics of a pneumatic tire. The rigid wheel includes a central portion and a plurality of circumferentially spaced mounting elements removably attached to a radially outer margin of the central portion. The tire is mounted on the wheel and engages the mounting elements such that portions of the tire not engaging the mounting elements are separated radially from the wheel by a space. The tire is configured such that portions of the tire not engaging the mounting elements flex inwardly toward the wheel when subject to ground engaging pressure, thereby minimizing ground penetration and soil disruption. The tire may include one or more tension elements embedded in the tire to increase the tire's strength and resilience.

A pneumatic tire includes a plurality of center lug grooves disposed at intervals in a tire circumferential direction that extend crossing a tire equator line and include a first groove turning portion and a second groove turning portion; a plurality of shoulder lug grooves disposed in the intervals between the plurality of center lug grooves in the tire circumferential direction extending outward in the tire width direction, an inner end in the tire width direction being disposed outward of an end of the center lug groove in the tire width direction; a pair of circumferential main grooves to which the ends of the center lug grooves and the inner ends of the plurality of shoulder lug grooves in the tire width direction alternately connect; and a circumferential secondary groove disposed around the entire circumference of the pneumatic tire with a wave-like shape.

A heavy-duty pneumatic tire includes a tread pattern including center lug grooves, shoulder lug grooves, a pair of circumferential primary grooves formed in wave-like shapes by alternately connecting ends of the center lug grooves and ends of the shoulder lug grooves and having a smaller width than the width of the shoulder lug grooves, center blocks defined by the center lug groove and the circumferential primary grooves, and a circumferential secondary groove extending in the tire circumferential direction so as to divide regions of the center blocks. The belt portion includes two or greater pairs of belts. The ratio of the width W8 of a belt having a smaller width in each of the belt pairs to the width W7 of a belt having a greater width is 0.75 or greater and 0.90 or less.

A tire tread having features that improve thermal wear performance is provided. A tread block is provided with an aperture. The aperture is positioned and sized in a manner that reduces stresses and/or strains in the tread block so as to reduce thermal wear. Certain variations in the depth and shape of the aperture are provided. Such tread feature can provide for a tire capable of operating at higher speeds for a given load.

A pneumatic tire is provided with four or more circumferential main grooves extending in a tire circumferential direction and five or more land portions defined by the circumferential main grooves. Additionally, second land portions are each provided with first through lug grooves and second through lug grooves that extend through the second land portion in a tire lateral direction and are adjacently arranged in the tire circumferential direction. Crossing angles of the first through lug grooves and the second through lug grooves with respect to the outermost circumferential main grooves are mutually different.

A heavy duty tire 10 includes a recess portion 34, a circumference-direction air entry and exit promotion portion 36 and an air-catching wall portion 42. The recess portion 34 is formed in a buttress portion 26 and opens to a tire outer side. The circumference-direction air entry and exit promotion portion 36 is disposed at one side of a floor portion 40 in a tire rotation direction and includes a slope 46 that, from the floor portion 40 toward a tire surface, gradually decreases in depth from the tire surface. The circumference-direction air entry and exit promotion portion 36 facilitates access of air toward the floor portion. The air-catching wall portion 42 is disposed at the opposite side of the floor portion 40 from the circumference-direction air entry and exit promotion portion 36. The air-catching wall portion 42 has a greater angle relative to the tire surface than the slope.

A tread pattern is provided with: shoulder lug grooves open at ground contact ends; center lug grooves each having opposite ends; circumferential primary grooves each formed in a wavy shape by connecting ends of the center lug grooves and the inner ends of the shoulder lug grooves in the width direction of the tire; and center blocks defined by the center lug grooves and the pair of circumferential primary grooves. The width of the circumferential primary grooves is smaller than the width of the shoulder lug grooves. The center lug grooves are tilted relative to both the circumferential direction and the width direction of the tire and each have a third groove turning portion and a fourth groove turning portion which protrude in the different directions in the circumferential direction of the tire.

A tire traction and vehicle turning device attaches to a tire of a vehicle to dislodge the vehicle from unfavorable ground conditions, such as snow, ice, or sand. The tire traction and vehicle turning device includes a tire-mounting body, a plurality of gripping treads, and a tie-down. The tire-mounting body attaches to a tire of the vehicle. The plurality of gripping treads provides a separate surface for the vehicle to gain traction due to differing coefficients of friction between the plurality of gripping treads and the grounds surface compared to the tire and the ground surface. The tie-down is positioned through the rim of the wheel to secure the tire-mounting body to the tire. As the tire is rotated, the tire traction and vehicle turning device is positioned between the ground surface and the tire, lifting the vehicle and propelling the vehicle in the direction the rotating tire is pointing.

Tread of a tire for an agricultural vehicle. The tread (2) comprises a first, median portion (21) having an axial width L.sub.1, at least equal to 0.25 times and at most equal to 0.75 times the axial width L, and second and third, lateral portions (22, 23) that respectively extend axially outwards from the first, median portion (21) as far as an axial end (E, E′) and have respective axial widths (L.sub.2, L.sub.3). Each lug portion (311) that is axially contained in the first, median portion (21) and extends radially inwards, from the contact face (6) as far as a first interface (7), over a radial distance D.sub.1 at least equal to 0.5 times and at most equal to 1 time the radial lug height H, includes a first elastomeric compound. Each lug portion (321) that is axially contained in one of the second or third, lateral portions (22, 23) and extends radially inwards, from the contact face (6) as far as a second interface (8), over a radial distance D.sub.2 at least equal to 0.5 times and at most equal to 1 time the radial lug height H, includes a second elastomeric compound.

The present technology provides a heavy duty pneumatic tire with a tread portion having a tread pattern including: a pair of circumferential primary grooves defined in a wave-like shape and extending in the tire circumferential direction; center lug grooves; center blocks; and circumferential secondary grooves extending in regions of the center blocks and open to the center lug grooves. The center lug grooves have two groove turning portions turned in a bend shape or a curved shape. The circumferential secondary grooves extend in an inclined manner relative to the tire circumferential direction. An inclination angle (θ.sub.4) of the circumferential secondary grooves relative to the tire circumferential direction is different from an inclination angle (θ.sub.1) of portions of the circumferential primary grooves relative to the tire circumferential direction, the portions extending toward the same side as a side in the tire width direction, toward which the circumferential secondary grooves are inclined.