Bridgestone Corporation

Naruhiro Akiyama

Kiyoshi Sakayori

Toru Kitajima

A tire building drum includes a hollow main shaft, a pair of bead lock sections arranged concentric with the main shaft and respectively holding a bead core of a tire, and a radially expansible/contractible carcass-supporting body defining an inner shape of a carcass member extending between the bead cores. The carcass-supporting body is composed of a pair of core bodies which are concentric with the main shaft and have a plurality of expansible/contractible rigid segments circumferentially abutting on and engaging with each other. The tire building drum is provided with a pair of sliders on which the core body and the bead lock section are mounted on a single side in the axial direction, slider-moving means for moving these sliders to any required radial position and segment-expanding/contracting means for expanding/contacting the segments of each core body to any required radial position.

Tire building drum

Method and apparatus for manufacturing pneumatic tires, wherein a green case comprised of at least one inner liner rubber member and a carcass ply member is formed on a first drum and transferred to a position around a second drum. The green case is the fixedly secured to the second drum by axially moving a pair of centering elements in opposite directions into pressure contact with opposite inner sides at the bead portions of the green case, and urging the inner peripheries of the bead portions by a pair of lock elements. The second drum is then caused to expand and undergo a width reduction, thereby expanding the green case into a toroidal shape. Sidewall rubber members, which have been previously wound on a pair of side bladders on the outer side of the lock elements, are expanded and reversed by inflating the side bladders and joined to the toroidal green case to thereby form a green tire.

Manufacturing system for pneumatic tires

The present invention is a method and apparatus for centering a belt-shaped material. A conveying direction leading end portion and a conveying direction trailing end portion of triangular portions of the belt-shaped material are displaced in advance in directions opposite directions in which the conveying direction leading end portion and the conveying direction trailing end portion of the belt-shaped material are displaced when applied onto a forming drum. Centering of a constant-width portion of the belt-shaped material is carried out as follows. A width of the constant-width portion of the belt-shaped material is measured while the belt-shaped material is conveyed. In accordance with the measured width, a distance between a pair of guide portions which are disposed so as to be movable in a widthwise direction of the belt-shaped material is adjusted. The belt-shaped material is passed through a space between the adjusted guide portions.

Method for centering belt-shaped material

A method and an apparatus are disclosed which are simplified in their constitution and capable of forming a strip material 58 that is inexpensive and yet of high quality by joining one on the other first and second strips 25, 41 shifted from each other in the lengthwise direction. During the joining the second strip 41 with the first strip 25, the second strip 41 is pulled by the transfer conveyor 11 and thereby drawn from the supporting means 42 and then fed to the transfer conveyor 11, and by virtue of this, the feed rate of the second strip 41 is identical to the traveling speed of the transfer conveyor 11 (the transfer speed of the first strip 25), thus leading to enhanced quality of the resulting strip material 58. In addition, since the transfer means 51 and the transfer conveyor 11 are required to be controlled only in timing of actuation, a controlling means therefor may be simple.

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Kodaira, Japan

Naruhiro Akiyama