Process and drum for constructing a green tire

An expandable drum for constructing a green tire comprising:

• a plurality of metal segments arranged to form a substantially cylindrical arrangement, which is adapted for radial expansion and compression;
• an elastically expandable casing slidably positionable over said plurality of metal segments, thereby forming a drum periphery, wherein said plurality of metal segments are radially expandable so that a diameter of said drum periphery corresponds to an inside diameter of a carcass sleeve;
• a plurality of voids formed in said drum periphery;
• an evacuating pump coupled to said plurality of voids in order to suction the carcass sleeve onto said drum periphery during a radial compression of said plurality of metal segments, whereby radial compression of the carcass sleeve occurs,
• wherein the plurality of voids comprises gullies arranged on the elastically expandable casing and a network of grooves coupled to the gullies.

An expandable drum for constructing a green carcass of a tire, the drum having a periphery and comprising:

• a plurality of metal segments positioned to form a substantially cylindrical arrangement, which is adapted for radial expansion and compression;
• a thick-walled casing comprising rubber, the thick-walled casing being positioned over the plurality of metal segments, thereby forming the drum periphery;
• the thick-walled casing comprising a plurality of voids arranged on an outer periphery of the thick-walled casing;
• and
• an evacuating pump coupled to the plurality of voids, wherein the plurality of voids suction the green carcass onto the drum periphery during compression of the drum periphery;
• the plurality of voids comprising circular gullies coupled to a network of axially arranged grooves arranged to provide a wave-free and smooth contraction of the green carcass during its compression, thereby avoiding bulges and creases in the contracting green carcass,
• wherein each of the circular gullies and the network of axially arranged grooves are in communication with the evacuating pump to create a vacuum in both the gullies and the network of grooves.

An expandable drum for constructing a green carcass of a tire, the drum having a periphery and comprising:

• a plurality of metal segments positioned to form a substantially cylindrical arrangement, which is adapted for radial expansion and compression;
• a thick-walled elastically expandable casing, the thick-walled elastically expandable casing being positioned over the plurality of metal segments, thereby forming the drum periphery;
• the thick-walled elastically expandable casing comprising a first plurality of voids arranged on an outer periphery of the thick-walled casing;
• an evacuating pump coupled to the first plurality of voids, wherein the first plurality of voids suction the green carcass onto the drum periphery during compression of the drum periphery;
• the first plurality of voids comprising circular gullies coupled to a network of axially arranged grooves arranged to provide a wave-free and smooth contraction of the green carcass during its compression, thereby avoiding bulges and creases in the contracting green carcass;
• and
• a second plurality of voids located on one of an inner surface of the thick-walled elastically expandable casing and an outer surface of the plurality of metal segments,
• wherein each of the circular gullies and the network of axially arranged grooves are in communication with the evacuating pump to create a vacuum in both the gullies and the network of grooves.