The present invention relates to a tire with main kerfs and sub-kerfs, and more particularly, to a tire with main kerfs and sub-kerfs, which maintains drainage performance and running and braking performance by additionally including an auxiliary groove and improves a flow of air and drainage performance by including an auxiliary flow tube.

A tire having high on-ice starting performance, the tire is provided with a plurality of circumferential direction grooves formed on a tread of the tire and extending in a tire circumferential direction, a plurality of width direction grooves extending in a direction intersecting the tire circumferential direction, a plurality of blocks demarcated by the circumferential direction grooves and the width direction grooves, and a plurality of width direction sipes formed on surfaces of the blocks and extending in the direction intersecting the tire circumferential direction, in which a distance P between the sipes 18z is set in a range of 4-12 mm.

A pneumatic tire comprises a plurality of blocks arranged on a tire ground contact edge. The plurality of blocks each comprise at least one main sipe that comprises: a two-dimensional sipe portion extending in a tire circumferential direction, and a three-dimensional sipe portion extending in a tire lateral direction that connects to the two-dimensional sipe portion.

A pneumatic tire, includes: an annular-shape tread portion; a sidewall portions; and bead portions. JIS hardness of tread rubber is within a range of 40 to 60 and snow traction index is 180 or higher. A rib positioned between circumferential grooves is demarcated in a center region of the tread portion. Closed grooves are formed in the rib. The closed grooves are inclined with regard to a tire axial direction such that a closed end faces a leading side. A groove wall of the closed groove on the leading side protrudes more outward in the tire axial direction than a groove wall on a trailing side. A difference between angles θ1 and θ2 of the groove walls on the leading and trailing sides of the closed grooves, respectively, with regard to the tire axial direction is within a range of 0°≤θ1-θ2≤5°.

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 tire having an outer middle land portion demarcated between an outer shoulder circumferential groove and an outer crown circumferential groove and located at an outer side of a vehicle when the tire is mounted on the vehicle, and an inner middle land portion demarcated between an inner shoulder circumferential groove and an inner crown circumferential groove and located at an inner side of the vehicle when the tire is mounted on the vehicle formed in a tread portion. The outer middle land portion has first outer middle sipes extending from the outer crown circumferential groove toward the outer shoulder circumferential groove and terminating within the outer middle land portion. The inner middle land portion has first inner middle sipes extending from the inner shoulder circumferential groove toward the inner crown circumferential groove and terminating within the inner middle land portion. An angle θ1 of each first outer middle sipe with respect to a tire axial direction is smaller than an angle θ2 of each first inner middle sipe with respect to the tire axial direction.

The present invention includes tire treads (10) and a method for forming tire treads (10) having a sipe (18) with a length extending between opposing terminal ends of the sipe and having a height and a thickness which is variable across the length and height of the sipe. The thickness of the sipe (18) includes a sipe portion arranged between the opposing terminal ends defining the sipe length and having a thick portion extending at least partially around a perimeter of a thin portion. The thin portion is substantially 0.2 millimeters or less thick and forms at least 40% of the surface area along each of the opposing sides of the sipe, the opposing sides being arranged on opposing sides of the sipe thickness.

A method of forming a tire includes a mold having a molding cavity defined at least in part by an outermost molding surface and a pair of opposing shoulder-forming portions. The mold includes a sipe-forming element spaced apart inwardly from the pair of opposing shoulder-forming portions with a knife edge oriented towards a first shoulder-forming portion and a knife edge translation member arranged outside the mold cavity and configured to translate in a direction towards the first shoulder-forming portion and from which a sipe-forming portion extends. The method further includes arranging an uncured tire tread within the mold, molding the uncured tire tread, and demolding the tire tread such that the sipe-forming element forms a sipe by the knife edge lacerating a thickness of the cured molded tread as the sipe-forming element is pulled in a direction toward the shoulder-forming portion.

A pneumatic tire includes first and second main grooves, and first sipes and auxiliary grooves on second land portions between the first and second main grooves, the auxiliary grooves opening to the second main grooves and terminating in the second land portions. The auxiliary grooves bend at a bend point and include a first portion extending from an opening end to the bend point, and a second portion extending from the bend point to a terminating end. A groove width of the first portion gradually reduces from the opening end to the bend point. Second sipes have an end that opens to each of the second main grooves and another end that opens to each of the terminating ends. Third sipes have an end that opens to the first main grooves and another end that opens to the first portions. The sipes are parallel to each other.

A center rib is formed by two circumferential main grooves. A main inclined groove and an auxiliary inclined groove are formed in the center rib. The main inclined groove is inclined with respect to the tire circumferential direction to become distanced from the tire equatorial plane from a leading side toward a trailing side in a tire rotational direction, a plurality of the main inclined grooves being juxtaposed in the tire circumferential direction and disposed alternately in the tire circumferential direction on both sides of the tire equatorial plane. The auxiliary inclined groove inclines with respect to the tire circumferential direction to become distanced from the tire equatorial plane from the leading side toward the trailing side in the tire rotational direction, a leading end and a trailing end terminating within the center rib while intersecting at least two of the main inclined grooves.