US 6,571,845 B1 · Low-section tire and mould and process for manufacturing a tire air tube

Abstract

A low-section tire includes an air tube including an internal wall and two air tube sidewalls. The internal wall comprises a greater rigidity than the tube sidewalls so that, when a carcass and the tube are mounted on a rim, and during inflation, the tube sidewalls contact the carcass sidewalls no later than the internal wall contacts a crown portion of the carcass. A process for manufacturing the air tube includes moulding two tube sidewalls separated from each other, moulding a central core, arranging the tube sidewalls and central core in a single vulcanization mould, closing the vulcanization mould to form the tube, feeding pressurized fluid into at least two distinct circumferential portions of the tube, and vulcanizing the tube to join the central core and tube sidewalls. A mould for manufacturing the an air tube includes two axially-external cheeks, two axially-intermediate male dies, and two axially-inner spacers.

Claims51

Dependent claims

A low-section tire for a vehicle wheel, comprising:

a carcass;
and
an air tube;
wherein the carcass comprises a toroidal form,
wherein the carcass further comprises a crown portion and two axially-opposite carcass sidewalls delimiting an inner cavity,
wherein the air tube comprises an elastomer material,
wherein the air tube further comprises an internal wall and a pair of axially-opposite air tube sidewalls,
wherein the internal wall separates the air tube into at least two distinct circumferential portions,
wherein the internal wall extends in a plane substantially normal to a rotation axis of the air tube,
wherein, when fully inflated, the air tube further comprises a right section in a meridian plane that is substantially elliptical, with a major axis parallel to the rotation axis of the air tube, and
wherein a rigidity of the internal wall is greater than a rigidity of the air tube sidewalls so that, when the carcass and the air tube are mounted on a rim, and during inflation of the air tube, the air tube sidewalls contact the carcass sidewalls before a time when a radially-outer portion of the internal wall contacts a radially-inner surface of the crown portion.

8 more elements

A tire wheel, comprising:

a rim;
and
a low-section tire mounted on the rim;
wherein the low-section tire comprises:
a carcass;
an air tube;
and
a belt structure disposed crownwise on the carcass;
wherein the carcass comprises a toroidal form,
wherein the carcass further comprises a crown portion and two axially-opposite carcass sidewalls delimiting an inner cavity,
wherein the air tube comprises an elastomer material,
wherein the air tube further comprises an internal wall and a pair of axially-opposite air tube sidewalls,
wherein the internal wall separates the air tube into at least two distinct circumferential portions,
wherein the internal wall extends in a plane substantially normal to a rotation axis of the air tube,
wherein, when fully inflated, the air tube further comprises a right section in a meridian plane that is substantially elliptical, with a major axis parallel to the rotation axis of the air tube, and
wherein a rigidity of the internal wall is greater than a rigidity of the air tube sidewalls so that, when the carcass and the air tube are mounted on the rim, and during inflation of the air tube, the air tube sidewalls contact the carcass sidewalls before a time when a radially-outer portion of the internal wall contacts a radially-inner surface of the crown portion.

13 more elements

A mould for manufacturing an air tube of elastomer material, comprising:

a pair of axially-external cheeks;
of axially-intermediate male dies;
and
a pair of axially-inner spacers;
wherein each cheek comprises, at a surface facing an opposing cheek, an annular cavity of substantially-semicircular right section, coaxial with a rotation axis of the air tube,
wherein each die comprises an axially-outer surface and an axially-inner surface,
wherein, for each die, the axially-outer surface comprises a first annular ridge coaxial with the rotation axis of the air tube,
wherein the first annular ridge comprises a semicircular right section,
wherein, when the mould is closed, the first annular ridge is housed in a corresponding annular cavity of an adjacent cheek,
wherein a radius of the first annular ridge is smaller than a radius of the corresponding annular cavity so as to delimit, when the mould is closed, a hollow space of a width corresponding to a sidewall of the air tube,
wherein, for each die, the axially-inner surface comprises a second annular ridge coaxial with the rotation axis of the air tube,
wherein the second annular ridge is axially aligned with a corresponding first annular ridge,
wherein the second annular ridge comprises a right section of substantially quadrangular shape,
wherein maximum radial sizes of the first and second annular ridges are substantially identical,
wherein the spacers comprise a radially-inner disc and a radially-outer concentric ring,
wherein the disc and the ring are coaxial with the rotation axis of the air tube,
wherein a diameter of the disc is less than a radially-inner diameter of the ring,
wherein the diameter of the disc corresponds to a diameter of a radially-inner edge of the annular cavities,
wherein the radially-inner diameter of the ring corresponds to a diameter of a radially-outer edge of the annular cavities,
wherein a thickness of the spacers is greater than a sum of axial sizes of the second annular ridges,
wherein mating of the spacers with the dies forms a hollow space corresponding to a shape of a central core of the air tube,
wherein the shape of the central core is determined by a mutual axial distance between the second annular ridges and by a geometric configuration determined by a radial distance between the second annular ridges and spacers,
wherein the central core comprises an annular configuration comprising an internal wall and two flanges,
wherein the internal wall separates the air tube into at least two distinct circumferential portions,
wherein the internal wall extends in a plane substantially normal to the rotation axis of the air tube,
wherein each flange extends perpendicularly from the internal wall in axially-opposite directions,
wherein the flanges comprise a radially-external flange and a radially-internal flange, and
wherein the cheeks, dies, and spacers are mutually removable with respect to each other.

25 more elements

A low-section tire for a vehicle wheel, comprising;

a carcass;
and
an air tube;
wherein the carcass comprises a toroidal form,
wherein the carcass further comprises a crown portion and two axially-opposite carcass sidewalls delimiting an inner cavity,
wherein the air tube comprises an elastomer material,
wherein the air tube further comprises an internal wall and a pair of axially-opposite air tube sidewalls,
wherein the internal wall separates the air tube into at least two distinct circumferential portions,
wherein the internal wall extends in a plane substantially normal to a rotation axis of the air tube,
wherein, when fully inflated, the air tube further comprises a right section in a meridian plane that is substantially elliptical, with a major axis parallel to the rotation axis of the air tube, and
wherein a rigidity of the internal wall is greater than a rigidity of the air tube sidewalls so that, when the carcass and the air tube are mounted on a rim, and during inflation of the air tube, a radially-outer portion of the internal wall contacts a radially-inner surface of the crown portion simultaneously with a complete lying down of the air tube sidewalls against the carcass sidewalls.