Abstract: A tire forming mold in which a depression for forming a land portion of a tread surface is provided in a molding surface forming a tread pattern of a tire. The tire forming mold has a pocket provided in the depression, a block fitted into the pocket to form an exhaust chamber in an inner portion of the pocket and holding a laminated blade, which is formed by superposing thin plates, so that one end portion is exposed to the molding surface and the other end portion is exposed to the exhaust chamber, and an exhaust hole having one end portion is communicated with the exhaust chamber and the other end portion is communicated with a mold back face or a mold split face.

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.

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: 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: An object of the present invention is to provide a pneumatic tire excellent in running performance on a rough road. In order to achieve the object, a pneumatic tire comprises a tread surface having a plurality of lug grooves each of which opens to a sidewall, the sidewall includes a plurality of protrusions disposed thereon, wherein each of the lug grooves includes a protruding strip portion disposed on a groove bottom of the lug groove and extending along an extending direction of the lug groove, the protruding strip portion has a start point thereof at an inner side than a ground-contact point in a width direction as viewed from a front side thereof, and extends up to one of the protrusions beyond an open end of the lug groove located at the sidewall side and is connected to the protrusion.

Abstract: An object of the present invention is to provide a pneumatic tire on a tread surface of which hand grooving can be carried out swiftly and easily, and a method of carrying out the hand grooving thereon. In order to achieve the object, a pneumatic tire comprises a tread surface formed with a plurality of grooves. The tread surface includes a guide line previously disposed as a reference for carrying out hand grooving. The guide line extends along at least one edge line of the grooves or a virtual extension line of at least one edge line of the grooves.

Abstract: A tire forming mold in which a depression for forming a land portion of a tread surface is provided in a molding surface forming a tread pattern of a tire. The tire forming mold has a pocket provided in the depression, a block fitted into the pocket to form an exhaust chamber in an inner portion of the pocket and holding a laminated blade, which is formed by superposing thin plates, so that one end portion is exposed to the molding surface and the other end portion is exposed to the exhaust chamber, and an exhaust hole having one end portion is communicated with the exhaust chamber and the other end portion is communicated with a mold back face or a mold split face.

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 t

Abstract: The pneumatic tire includes an outer tire installed such that a bead portion is inscribed in a rim flange, and an inner tire inserted inside the outer tire and installed such that a bead portion is inscribed in the bead portion of the outer tire. A plurality of protrusions are provided in an annular outer side wall surface region extending in an outer side in a tire diametrical direction from a bead heel of the inner tire so as to be differentiated in the positions in the tire diametrical direction and overlap with one another when seen in a tire circumferential direction, and a ventilation path for feeding an air supplied to a portion near the bead heel into an air chamber is formed between the protrusions in a state where the outer side wall surface region is inscribed in the bead portion.

Abstract: A pneumatic tire comprising a shoulder rib segmented into a main rib located at the inner side thereof in a width direction of the tire and a thin rib located at the outer side thereof in the width direction of the tire by a thin groove extending along a circumferential direction of the tire, wherein the thin groove includes a large-width portion having a relatively larger groove width and a small-width portion having a relatively smaller groove width continuously formed one after the other along the circumferential direction of the tire, and an inner wall of the large-width portion located at the thin rib side is disposed at a further outer side with respect to an inner wall of the small-width portion located at the thin rib side as viewed in the width direction of the tire, a protruding portion protruding outwardly in the width direction of the tire from an edge line of the thin rib located at the outer side in the width direction of the tire is formed at a position where the large-width portion is disposed

Abstract: A pneumatic tire comprising, on a tread face of the tire, a shoulder land portion extending in a circumferential direction of the tire, and a thin groove extending in the circumferential direction of the tire adjacent to a contact end of the shoulder land portion where comes into contact with the ground and segmenting the shoulder land portion into a main land portion located at the inner side thereof as viewed in the width direction of the tire and a sacrifice land portion located at the outer side thereof as viewed in the width direction of the tire, wherein the thin groove includes an enlarged portion extending in the circumferential direction of the tire in which a groove width thereof at groove bottom is enlarged toward the sacrifice land portion side only, and a protruding portion that protrudes toward the groove bottom side along the inner wall located at the sacrifice land portion side and extends in the circumferential direction of the tire.

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: The pneumatic tire has the characteristics in that the pneumatic tire is provided with a plurality of main grooves 1 extending in the tire circumferential direction formed on a tread T, a rib 2 formed at least on the shoulder portion of the tread T, a first fine groove 3 extending in the tire circumferential direction formed on the inner side of the tire width direction than a grounding end E, and the thin rib 4 formed by the first fine groove 3 and the grounding end E, wherein a second fine groove 5 is formed on the outer side of the tire width direction than the grounding end E, the second fine groove 5 is on the outer side of the tire width direction than a virtual surface S1 that passes the grounding end E and is vertical to the tire rotational axis.