Bridgestone Corporation

Keiji Yamamoto

Takashi Yokoi

Jumei Harada

A variable contour rubber extruder comprises a rotary driving roller, a main body forming therein an eccentric arc chamber with the rotary driving roller, and a movable mouth piece forming with a barrel surface of the rotary driving roller an opening of variable sectional area for extruding rubber material. The movable mouth piece comprises a center piece movable toward and away from the barrel surface of the rotary driving roller and a pair of side pieces overlapping the center piece and slidably adjustable in directions in parallel with an axis of the rotary driving roller.

Variable contour rubber extruder

A rotary roll-type rubber extruder including a roll having an outer cylindrical surface rotatively driven by driving means, a housing having a stationary concave surface spaced from and in opposition to the rotating outer cylindrical surface of said roll between a pair of sidewalls close to the outer cylindrical surface of the roll to form a define chamber with the roll, and a mouthpiece detachably secured to the housing to form a defined extruding opening with the roll at an outlet of the defined chamber. The concave surface of the housing is determined such that pressure gradients at mouthpieces are within a quadrilateral area having four corners corresponding to pressure gradients 65 and 150 kg/cm.sup.3 at a 1 mm opening mouthpiece and pressure gradients 11 and 23 kg/cm.sup.3 at a 5 mm opening mouthpiece in a graph having an ordinate in logarithm showing the pressure gradients ##EQU1## and an abscissa in logarithm showing heights mm of openings of the mouthpieces.

Growing community of inventors

Tokorozawa, Japan

Keiji Yamamoto