| 摘要 |
PROBLEM TO BE SOLVED: To suppress the occurrence of undulation or air pocket in the outer end portion of a tread rubber. SOLUTION: A tread molding drum 20 includes a band forming surface part 21 where an outer peripheral surface 21S curvingly extends in a projectingly circular arc shape along a tread profile and spirally winds a band strip 10, and a stepped projecting part 22 which rises in a stepped shape from the both ends of the band forming surface part 21 to extend to the outside in the axial direction, and where the outer peripheral surface 22S is parallel to the outer peripheral surface 21S of the band forming surface 21. A raised height H from the band forming surface part 21 of the stepped projecting part 22 is set within the range of±0.5 mm of the thickness T of the band strip 10. COPYRIGHT: (C)2011,JPO&INPIT
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