The vent valve (10) for venting bores of vulcanization molds, which includes the sleeve (1), with the inner cylindrical hollow (1.1), ended with the valve conical hole (1.2) and the cylindrical hole (1.4) along the sides, whereas the sleeve (1) may be inserted into the vulcanization mold hole, the pin (2), movably located on the spring (3) in the inner cylindrical hollow (1.1), whereas the pin (2) contains the lower cylindrical part (2.4), ended in its lower part with the lower conical part (2.4.1), and the upper conical part in the upper part (2.4.2), the upper conical part (2.4.2) is followed by the central cylindrical part (2.5), followed by the connecting cylindrical part (2.6), whereas the diameter of the central cylindrical part (2.5) is smaller than the connecting cylindrical part (2.6) as well as the lower cylindrical part (2.4). The lower cylindrical part (2.4) and the central cylindrical part (2.5) are divided into four flexible legs (2.7) to (2.10), forming the flexible collet. Four flexible legs (2.7 to 2.10) are shaped identically and partially reach the connecting cylindrical part (2.6).

A tire mold comprises sector molds for forming a tread portion of a tire and mold pins provided on the sector molds for forming insertion holes in the tread portion. The insertion holes each comprise a first hole portion with a first inner diameter where a body portion of a stud pin is disposed and a second hole portion with a second inner diameter greater than the first inner diameter where a bottom flange portion of the stud pin is disposed. The mold pins each comprise a trunk portion with a first outer diameter for forming the first hole portion and a tip portion with a second outer diameter greater than the first outer diameter for forming the second hole portion.

Embodiments of the invention include methods for reducing deformation of a sipe-molding member (10) arising during manufacturing operations, and sipe-molding members (10) comprising a sipe-forming portion (12) and a plurality of stiffening members (20) spaced along the sipe-forming portion. The sipe-forming portion (12) has a length extending in a lengthwise direction of the sipe-molding member (10), a height configured to extend into a depth of a molding cavity, and a thickness extending perpendicular to both the length and height. The sipe-molding member (10) is configured to form a sipe having a thickness commensurate with the thickness of the sipe-forming portion, a length formed by at least a portion of the length of the sipe-forming portion, and a depth formed by at least a portion of the height of the sipe-forming portion. Each of the plurality of stiffening members (20) extend outwardly from the thickness of the sipe-forming element. Further embodiments include methods of forming a molded tire tread.

A tire vulcanization mold 10 of an embodiment includes a side mold 14 having a side molding surface 20 for molding a side wall portion. The side mold 14 includes: a side mold body 24 having recesses 30 provided in the side molding surface 20; a side piece 26 fitted into the recess 30 to form a vent gap 28 with a wall surface of the recess; and a replacement piece 44 for displaying information closely fitted into a mounting hole 42 provided in the side molding surface 20 without a gap therebetween. The replacement piece 44 is provided in the side piece 26 or in the side mold body 24 so as not to span the side piece 26 and the side mold body 24.

The molding element has a plurality of contacting element delimited by grooves, the molding element having a molding surface for forming a contact face of the contacting element intended to come into contact with ground during rolling and a groove forming rib portion for forming the groove comprising two opposed rib side faces for forming two opposed groove side faces and a rib top face connecting two rib side faces for forming a groove bottom, the groove forming rib portion providing a space opening to at least one of the rib side faces and/or to the rib top face and an insert being received in the space for forming a portion of the groove and a closing device in the groove, the insert comprises at least one notched plate of thickness t1, the notched plate includes at least one notch for forming a flexible fence of the closing device.

A set (1) of moulding elements intended to be added to a mould comprise a main moulding element (10) and a secondary moulding element (20) comprising an edge (21), said main moulding element (10) comprising a contact zone (11) adapted to be in contact with all or part of the edge (21) of the secondary element, said contact zone (11) not being flat, and the edge (21) of said secondary moulding element (20) comprising at least one recessed portion (22) complementary to the non-flat contact zone (11) of the main element.

The tire vulcanization mold includes a molding surface for molding a tire surface of a pneumatic tire set in a cavity, a concave portion provided on the molding surface, and a vent plug provided in the concave portion. The vent plug includes a housing having a cylindrical shape and including an exhaust passage, a stem that is inserted in the housing and configured to open and close the exhaust passage of the housing, and an urging member urging the stem toward the cavity side. The concave portion has a narrow portion having a width substantially equal to the outer diameter of the housing of the vent plug, and the vent plug is disposed in the narrow portion.

A tire vulcanizing mold is disclosed capable of accurately providing a clearance, from which air existing between a green tire and a side mold is released, on a side shaping surface and thereby preventing shaping defect. The tire vulcanizing mold includes an upper and lower pair of side molds having side shaping surfaces, each of which shapes a sidewall of a tire. Each of the side molds includes a side mold main body, plural pieces, and a clearance provided between the side mold main body and each of the pieces. The side mold main body includes plural recesses, each of which is closed in a tire circumferential direction and a tire radial direction and is opened to a side shaping surface, at spaced intervals in the tire circumferential direction. Each of the pieces is fitted into the recess and forms the side shaping surface with the side mold main body.

A front surface of a stencil plate to be mounted on a mounting groove of a tire vulcanizing mold is provided with: a first recess for forming a protruding identification mark on an outer surface of a tire; and a second recess on which a screw having a flat head bottom surface is disposed, the second recess being formed on a periphery of a through hole. A back surface of the stencil plate is provided with: a first protrusion corresponding to the first recess and protruding toward a groove bottom surface; and a second protrusion corresponding to the second recess and having a flat surface capable of being brought into surface contact with the groove bottom surface. When a protrusion amount of the first protrusion is H1 (mm), and a protrusion amount of the second protrusion is H2 (mm), 0H2H1 is satisfied.

A tire vulcanization mold manufacturing method including: a process of preparing plural mold material blocks, an inner face of an axial direction central portion of each of the mold material blocks being formed with a molding protrusion in a complementary relationship with a wide groove of a tire, and each of the mold material blocks having a same circular cylindrical shape; a process of forming, by machining, a plurality of slits penetrating through the axial direction central portion of each of the mold material blocks such that the penetrating slits each extend along the axial direction and are separated from each other in a circumferential direction, and forming mold pieces between adjacent the penetrating slits with a portion of the molding protrusion formed on an inner face of the mold pieces; a process of cutting out the mold pieces from remainder rings that extend continuously in the circumferential direction at one axial direction end and the other axial direction end of the mold pieces; and a process of repeatedly performing a task to extract the mold pieces from the plurality of mold material blocks one at a time in sequence and to install the mold pieces at inner faces of plural holders so as to form plural mold segments each configured by a holder and a mold piece.