US 12,220,888 B2
Vulcanization mold and pneumatic tire manufactured with the mold
Tatsuhiko Hatano, Tokyo (JP); Yasuo Shibata, Tokyo (JP); and Tatsuya Nakai, Tokyo (JP)
Assigned to BRIDGESTONE CORPORATION, Tokyo (JP)
Appl. No. 17/311,124
Filed by BRIDGESTONE CORPORATION, Tokyo (JP)
PCT Filed Nov. 15, 2019, PCT No. PCT/JP2019/044941
§ 371(c)(1), (2) Date Jun. 4, 2021,
PCT Pub. No. WO2020/129504, PCT Pub. Date Jun. 25, 2020.
Claims priority of application No. 2018-237715 (JP), filed on Dec. 19, 2018.
Prior Publication US 2021/0379849 A1, Dec. 9, 2021
Int. Cl. B29D 30/06 (2006.01)
CPC B29D 30/0606 (2013.01) [B29D 2030/0612 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A vulcanization mold in which an annular mold for forming a tire tread of a pneumatic tire is split in a circumferential direction into a plurality of sector molds and the sector molds are moved in directions toward a center of the annular mold and combined with each other to clamp a raw tire on an inner side of the sector molds to vulcanization mold the raw tire,
each of the sector molds having blades implanted on a mold surface thereof, the blades being plate members extending in a tire widthwise direction and being configured to form groove lines on the tire tread,
each of the blades having
a blade proximal end portion embedded into a respective one of the sector molds,
a blade distal end side thick portion expanded in a thicknesswise direction on a distal end side, and
a blade connection portion that connects the blade proximal end portion and the blade distal end side thick portion to each other, wherein
a blade density is a number of the blades implanted on the sector mold per unit length in a circumferential direction,
circumferential end portion side regions of the sector molds have a first plurality of the blades,
a circumferential central portion side region of the sector molds has a second plurality of the blades, and
the blade density of the first plurality of blades is lower than the blade density of the second plurality of blades.