Abstract:
A pneumatic tire of the invention includes: a stepped-shaped raised area provided in the main groove positioned at a center area of the tire so as to be continued circumferentially of the tire, connected to either the main groove walls, and raised from the groove bottom; and a ridge lower than a tread surface of the tire in each of the main grooves on both outsides of the main groove at the center area of the tire so as to be raised from the center of the groove bottom continuously along the length thereof without being joined with the groove walls, and the angle of inclination of the main groove walls with respect to the normal line of the tangential line on the tread surface of the main groove portion is parallel to each other or is 5° or smaller.
Abstract:
A pneumatic tire having improved wear resistance, especially improved uneven wear resistance (such as river wear), is offered. The tire that is a rib-pattern tire has five ribs extending circumferentially of the tire. The ribs include a center rib and intermediate ribs located on the opposite sides of the center rib that is located on the equator line of the tire. Closed sipes are formed at least in the center rib and in the intermediate ribs. Each sipe is located in the lateral center of the corresponding rib. Both ends of each sipe terminate within the corresponding rib. The closed sipes are successively offset circumferentially among the ribs and arranged in a periodic pattern on the outer surface of the tire. The closed sipes in the ribs are so arranged that when they are optically projected onto the equator line of the tire, the sipes do not overlap circumferentially of the tire among the ribs.
Abstract:
A pneumatic tire has a pair of bead portions, side wall portions extending to an outer side in a tire diametrical direction from the bead portions, and a tread portion connected to an outer end in a tire diametrical direction of each of the side wall portions. An outer wall surface of the side wall portion is provided with a circumferential projection annularly extending along a tire circumferential direction, and a plurality of diametrical projections extending to an inner side in a tire diametrical direction from the circumferential projection and arranged so as to be spaced in the tire circumferential direction. A gap portion formed between the diametrical projections is open to an inner side in the tire diametrical direction.
Abstract:
A pneumatic tire assembly comprising a rim, a pneumatic tire that has a double structure including an outer tire and an inner tire inserted thereinto, and is assembled with the rim, and air chambers formed inside and outside the inner tire, wherein the rim includes a pair of bead seats on which bead portions of the outer tire and the inner tire are placed, a first rim flange protruding outward in a diameter direction of the tire from a side end of the bead seat, a second rim flange disposed inside the first rim flange in a rim width direction and formed on at least one of the bead seats while protruding therefrom, and an air valve provided to the second rim flange, the outer tire is held by the first rim flange and the second rim flange with the bead portion thereof being nipped therebetween, the inner tire is mounted with the bead portion thereof being in internal contact with the second rim flange, and in an outer wall surface area of the inner tire extending outward from a position of a maximum height of the second rim flange in a diameter direction of the tire, a groove portion for feeding air supplied via the air valve into the air chamber formed outside the inner tire is formed into a concave shape.
Abstract:
The manufactured pieces are the ones both end surfaces thereof in the tire circumferential direction are cut from the pieces before cutting 1 and the pieces before cutting 1 have the cutting regions whose cross-sectional shapes in the tire width direction are the same at both ends of its circumferential direction. And in the cutting process of cutting the pieces for modifying the lengths in the circumferential direction from each of the pieces before cutting 1, in order that the length in the tire circumferential direction of each piece after cutting and that both of the end surfaces in the circumferential direction of the piece after cutting are included in the cutting regions, the cutting lines of each piece are set at different not less than two positions (a, a′ and b, b′) in the tire circumferential direction and the pieces are cut by either one of the set cutting lines.
Abstract:
The mold for molding a tire has the contact part 42 that contacts with the end surface in the circumferential direction of the adjacent pieces and the non-contact part 44 that does not contact with the end surface in the circumferential direction of the adjacent pieces at the end surface 40 in the circumferential direction of the piece 30 in the segments right after the mold of the cycle of the tire molding process in which the opening and closure of the mold are repeated is closed, and the non-contact part 44 is present in the inner side of the tire radial direction, the contact part 42 is present outside of the tire radial direction than the non-contact part, and right before the mold in the cycle of the tire molding process is opened, the end surface 40 in the circumferential direction of the piece 30 in the segments contacts with the end surface 40 in the circumferential direction of the adjacent pieces in the non-contact part 44.
Abstract:
A sipe blade for forming a sipe with one end opened and the other end closed in a land portion on a tread surface of a tire includes a front-end portion that forms the closed end of the sipe and a connection-end portion that forms the open end of the sipe being connected to a rib that forms a groove. A first thickness of the front-end portion is larger than a second thickness of a thinnest portion. A third thickness of the connection-end portion is 3 mm or less and is the largest thickness in a portion between the front-end portion and the connection-end portion, and the ratio of the third thickness with respect to the second thickness; i.e., the third thickness/the second thickness is 1.2 to 3.0.
Abstract:
A groove bottom of a circumferential groove formed in a tread surface is provided with a protruding stripe extending along an extending direction of the circumferential groove. The protruding stripe is provided with a top head portion protruding toward a tire outer circumferential side, and a base portion which is narrower than the top head portion and connects the top head portion and the groove bottom. If a small stone is pinched, the top head portion is inclined around the base portion, and the protruding stripe is deflected as a whole, thereby generating a reaction force on the basis of a deformation restoring force.
Abstract:
In a block pattern, transverse grooves 2 are provided that open to grounding edge in the tire width direction, at bottoms of said transverse grooves, protrusions 3 are provided that extend along the direction of said transverse grooves, said protrusions 3 have starting points in the center side C from the grounding edge T in a tire front view, and said protrusions have terminal points that go over said grounding edge T and in the outer side from said grounding edge T. Further, it is preferable that the protrusions 3 of said transverse grooves are provided with divided protrusions 4 that are formed dividedly in the center side from the grounding edge.