A heavy-duty pneumatic tire comprises a crown rib and a middle rib. The crown rib is provided with crown sipes crossing the crown rib. The middle rib is provided with middle sipes crossing the middle rib and a middle shallow groove having a smaller depth and a larger width than the middle sipes. The middle shallow groove comprises a circumferential middle shallow groove extending in a tire circumferential direction and lateral middle shallow grooves extending from an axially inner side edge (Ema) of the middle rib to the circumferential middle shallow groove so as to terminate at a position thereof.

A pneumatic tire includes a sipe formed in a tread rubber which includes an opening extending in a first direction in a surface of the tread rubber. The opening is provided between a first edge of the tread rubber extending in the first direction and a second edge of the tread rubber adjacent to the first edge in a second direction orthogonal to the first direction. The first edge and the second edge are divided into a first range defined in the first direction and a second range different from the first range. In the first range, the first edge is provided with a first chamfered portion. In the second range, the second edge is provided with a second chamfered portion. In the first range, the second edge is not provided with a chamfered portion. In the second range, the first edge is not provided with a chamfered portion.

An outer shoulder land region includes first shoulder lateral grooves each extending axially inwardly from an outer tread ground contact edge to have a first inner end in the tyre axial direction within the outer shoulder land region, first outer shoulder lateral sipes each connecting between the first inner end and an outer shoulder main groove, and second outer shoulder lateral sipes each extending axially inwardly from the outer tread ground contact edge to have a second inner end positioned on an axially outer side of the first inner ends. An outer middle land region includes outer middle lateral sipes each smoothly connected with the respective first outer shoulder lateral sipe with the outer shoulder main groove therebetween. Each of the outer middle lateral sipes connects between the outer shoulder main groove and an outer crown main groove and has a third inner end within the outer middle land region.

A pneumatic tire having lug grooves in shoulder land portions that each include one end reaching at least a ground contact edge and an other end terminating in the shoulder land portion. Sipes in the shoulder land portions each include one end communicating with a shoulder main groove and an other end terminating in a ground contact region. Lug grooves in intermediate land portions each include one end communicating with the shoulder main groove and an other end terminating in the intermediate land portion. Sipes in the intermediate land portion each include one end communicating with a center main groove and an other end terminating in the intermediate land portion. Sipes in the center land portion each include one end communicating with the center main groove and an other end terminating in the center land portion without exceeding a tire center line.

Provided are tractor wheels for a downhole tractor. An example tractor wheel comprises a series of continuous springs disposed on the circumference of the tractor wheel, wherein the individual continuous springs in the series of continuous springs are separated by a gap, and a void disposed on the interior of the tractor wheel and that is continuous about the circumference of the tractor wheel.

A tire includes a middle land portion between a crown main groove and a shoulder main groove. The middle land portion is provided with a first middle lug groove extending axially outwardly from the crown main groove, a second middle lug groove extending axially inwardly from the shoulder main grooves wherein the first and second middle lug grooves are arranged alternately in a tire circumferential direction, and a first middle sipe provided between the first and second middle lug grooves. The first middle sipe includes a crown-side middle sipe element extending axially outwardly from the crown main groove, a shoulder-side middle sipe element extending axially inwardly from the shoulder main groove at a location different from an extension line of the crown-side middle sipe element and a connecting middle sipe element connecting therebetween.

A tread pattern of a pneumatic tire includes circumferential main grooves, lug grooves and first and second sipes connecting the circumferential main grooves, a block land portion defined by the circumferential main grooves and the lug grooves and including the sipes. The lug grooves and the first and second sipes have a shape that projects toward one direction in the circumferential direction. A shallow depth groove raised bottom is provided in a turning portion where the lug groove includes a projecting apex. The projecting apex of a sipe turning portion including the projecting apex of the first sipe is within the range of the shallow depth groove raised bottom, and is inward in the lateral direction compared with the position of the projecting apex of a sipe turning portion including the projecting apex of the second sipe.

A tire includes a tread portion including a first land region defined by main grooves. The first land region includes a first longitudinal edge and a second longitudinal edge, and a ground contacting surface defined between the first longitudinal edge and the second longitudinal edge. The first land region is provided with two first grooves and a second groove. Each of the first grooves extends so as to connect the first longitudinal edge and the second longitudinal edge. The second groove extends so as to connect the first longitudinal edge and the second longitudinal edge while intersecting with each of the two first grooves. The second groove is not connected with other grooves than the first grooves in the ground contacting surface.

In a pneumatic tire, an intermediate land portion is provided with a plurality of lug grooves having acute bent portions and a plurality of sipes extending in a direction that intersects with the lug grooves. The lug grooves are disposed so as not to overlap one another in the tire circumferential direction, and each have one end that opens to an outer main groove and an other end that terminates in the intermediate land portion. When pitches, which serve as reference positions, are defined based on end points at which the lug grooves open to the outer main groove, the sipes each are disposed to be located inside one of the pitches, and the groove area ratio in the pitches in the intermediate land portion is in the range from 15% to 25%.

A pneumatic tire includes a tread portion including an inboard tread region between a tire equator and an inboard tread edge, and an outboard tread region between the tire equator and an outboard tread edge. The inboard tread region is provided with a first main groove extending and a second main groove each extending continuously in the tire circumferential direction. The outboard tread region is provided with a plurality of recesses that are not in communication with other grooves. The recesses include a plurality of deep bottom recesses having depths equal to or more than 5 mm. A total of opening areas of the deep bottom recesses on a ground contact surface of the tread portion is equal to or less than 5% of a surface area of the outboard tread region that is obtained by filling up all grooves and recesses provided thereon.