Patent EP0103984A2 successfully refreshed from Google Patents.
EP0103984A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Pneumatic radial tire and mould of manufacturing the same
Assignee: Bridgestone Corp
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Filing: 1983-08-15
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Granted: —
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Expires: 2003-08-15
Abstract
Abstract A pneumatic radial tire having reduced rolling resistance and simultaneously improved steering stability and riding comfort during running without adversely affecting the wet performance and durability thereof is obtained by making higher the carcass maximum width position (Q) and the carcass curvature reverse position (D), or enlarging the curvature of the carcass in the radially outer zone of the carcass maximum width position and simultaneously the carcass curvature reverse extent in the radially inner zone of the sidewalls so as to intentionally deviate from the naturally equilibrated configuration. A method of manufacturing a pneumatic radial tire having reduced rolling resistance uses a mould for vulcanizing and forming the tire therein, which mould has a particular shape of cavity having a foot width 20-50% wider than the rim width and diverging progressively from corresponding shoulder portions to the wider foot portion of the cavity.
Inventors
- 👤 Minoru Togashi
- 👤 Kenshiro Kato
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 17:12
CPC Classifications
B; B60; B60C; B60C3/00; B60C3/04; B60C15/00; B60C15/06; B60C9/00; B60C9/02; B60C9/0292
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
357 words
A pneumatic radial tire including a pair of sidewalls(5), bead portions at the respective radially inner ends of the sidewalls, a crown portion(6) extending between the radially outer ends of the sidewalls, a carcass(3) comprising at least one ply including organic fibre cord layers and having ends turned back about bead wires(l) embedded in the said - bead portions to form turned-back portions, and hard rubber fillers(2) disposed between the said carcass ply and the turned-back portions thereof, characterized in that the carcass has, on each side of a plane including the equatorial line of the tire in a radial cross-section passing through the rotational axis of the tire, an outwardly extending configuration with a centre of a radius of curvature positioned inside the carcass in a radially outer zone from a carcass maximum width position(Q) to the said crown portion and further having an inwardly extending configuration continuous with the said outwardly extending configuration with a centre of a radius of curvature positioned outside the carcass in a radially inner zone from the said carcass maximum width portion to the said bead portion when the tire mounted on a rim(7) is inflated to an internal pressure 5% of normal internal pressure; and in that the said outwardly extending configuration of the carcass in the said radially outer zone is maintained permitting a comparatively small change in configuration, while the said inwardly extending configuration of the carcass in the radially inner zone is changed into a modified inwardly extending configuration with an increased radius of curvature when the tire on the rim is inflated to the normal internal pressure; and in that the height(E) of the said carcass maximum width portion(Q) from the bead base is within a range of 50-65% of the height(H) of the outermost portion of the crown portion from the bead base, and the height(D) of the junction of the said outwardly and inwardly extending configurations from the bead base is within a range of 20-35% of the said height(H) of the outermost portion of the crown portion when the tire on the rim is inflated to the normal internal pressure and equilibrated.
Claim 2
Dependent Claim
357 words
A pneumatic radial tire including a pair of sidewalls(5), bead portions at the respective radially inner ends of the sidewalls, a crown portion(6) extending between the radially outer ends of the sidewalls, a carcass(3) comprising at least one ply including organic fibre cord layers and having ends turned back about bead wires(l) embedded in the said - bead portions to form turned-back portions, and hard rubber fillers(2) disposed between the said carcass ply and the turned-back portions thereof, characterized in that the carcass has, on each side of a plane including the equatorial line of the tire in a radial cross-section passing through the rotational axis of the tire, an outwardly extending configuration with a centre of a radius of curvature positioned inside the carcass in a radially outer zone from a carcass maximum width position(Q) to the said crown portion and further having an inwardly extending configuration continuous with the said outwardly extending configuration with a centre of a radius of curvature positioned outside the carcass in a radially inner zone from the said carcass maximum width portion to the said bead portion when the tire mounted on a rim(7) is inflated to an internal pressure 5% of normal internal pressure; and in that the said outwardly extending configuration of the carcass in the said radially outer zone is maintained permitting a comparatively small change in configuration, while the said inwardly extending configuration of the carcass in the radially inner zone is changed into a modified inwardly extending configuration with an increased radius of curvature when the tire on the rim is inflated to the normal internal pressure; and in that the height(E) of the said carcass maximum width portion(Q) from the bead base is within a range of 50-65% of the height(H) of the outermost portion of the crown portion from the bead base, and the height(D) of the junction of the said outwardly and inwardly extending configurations from the bead base is within a range of 20-35% of the said height(H) of the outermost portion of the crown portion when the tire on the rim is inflated to the normal internal pressure and equilibrated.
Claim 3
Dependent Claim
46 words
A tire as claimed in Claim 1, characterized in that the said change(f) in configuration is within a range of 5-10% of the height(D) of the junction of the said outwardly and inwardly extending configurations when the internal pressure is increased to the normal internal pressure.
Claim 4
Dependent Claim
44 words
A tire as claimed in Claim 1 or 2., characterized in that each said hard rubber filler(2) tapers from a position adjacent the upper portion of the respective said bead wire(1) to at least the junction(D) of the said outwardly and inwardly extending configurations.
Claim 5
Dependent Claim
42 words
A tire as claimed in Claim 3, characterized in that each said turned-back portion of the carcass ply extends beyond the radially outer end of the respective hard rubber filler(2) but does not extend beyond the said carcass maximum width position (Q).
Claim 6
Dependent Claim
26 words
A tire as claimed in any of Claims 1 to 4, characterized in that each said hard rubber filler(2) has a Shore A hardness of 80-97°.
Claim 7
Dependent Claim
35 words
A tire as claimed in any of Claims 1 to 5, characterized in that each said hard rubber filler(2) has a loss tangent of 0.15-0.25 and a loss modulus of 8.0x10 7 -2.5x10 8 dyne/cm.
Claim 8
Dependent Claim
362 words
A pneumatic radial tire including a pair of sidewalls(5), bead portions at the respective radially inner ends of the sidewalls, a crown portion(6) extending between the radially outer ends of the sidewalls, a carcass(3) comprising at least one ply including organic fibre cord layers and having ends turned back about bead wires(l) embedded in the said bead portions to form turned-back portions, at least two belt layers(4) consisting of rubber coated high modulus cords arranged at comparatively small angles with respect to the central circumferential line of the tire and intersecting each other, and hard rubber fillers(2) disposed between the said carcass ply and the turned-back portions thereof, characterized in that the carcass has, on each side of a plane including the equatorial line of the tire in a radial cross-section passing through the rotational axis of the tire, a radial surface profile so selected that a ratio of radii R/R' is within a range of 0.65-0.85 and f is within a range of 5-10 mm when the tire is mounted on a normal rim(7) and inflated to normal internal pressure, where R' is a radius of a standard circle passing through points B, E and C, where the point B is in intersection of the carcass and a line extending parallel with the said rotational axis and passing through a point at which a flange of the rim departs from the tire, the point C is an intersection of the carcass and a line extending through the point B and perpendicular to the rotational axis of the tire, and the point E is an intersection of a line extending through a middle point D of a line segment BC and parallel with the rotational axis and a line extending through a carcass maximum width point F and perpendicular to the rotational axis, and R is a radius of profile curvature of a shoulder passing through the said point C, and' where f is the maximum distance between an arc of the said standard circle and the remaining carcass line . extending from the said profile curvature of the said shoulder to the point B having a single carcass curvature reverse position.
Claim 9
Dependent Claim
362 words
A pneumatic radial tire including a pair of sidewalls(5), bead portions at the respective radially inner ends of the sidewalls, a crown portion(6) extending between the radially outer ends of the sidewalls, a carcass(3) comprising at least one ply including organic fibre cord layers and having ends turned back about bead wires(l) embedded in the said bead portions to form turned-back portions, at least two belt layers(4) consisting of rubber coated high modulus cords arranged at comparatively small angles with respect to the central circumferential line of the tire and intersecting each other, and hard rubber fillers(2) disposed between the said carcass ply and the turned-back portions thereof, characterized in that the carcass has, on each side of a plane including the equatorial line of the tire in a radial cross-section passing through the rotational axis of the tire, a radial surface profile so selected that a ratio of radii R/R' is within a range of 0.65-0.85 and f is within a range of 5-10 mm when the tire is mounted on a normal rim(7) and inflated to normal internal pressure, where R' is a radius of a standard circle passing through points B, E and C, where the point B is in intersection of the carcass and a line extending parallel with the said rotational axis and passing through a point at which a flange of the rim departs from the tire, the point C is an intersection of the carcass and a line extending through the point B and perpendicular to the rotational axis of the tire, and the point E is an intersection of a line extending through a middle point D of a line segment BC and parallel with the rotational axis and a line extending through a carcass maximum width point F and perpendicular to the rotational axis, and R is a radius of profile curvature of a shoulder passing through the said point C, and' where f is the maximum distance between an arc of the said standard circle and the remaining carcass line . extending from the said profile curvature of the said shoulder to the point B having a single carcass curvature reverse position.
Claim 10
Dependent Claim
23 words
A tire as claimed in Claim 7, characterized in that the said profile curvature of the said shoulder is slightly bulged when inflated.
Claim 11
Dependent Claim
83 words
A tire as claimed in Claim 7, characterized in that the said profile curvature of the said shoulder passes through points F, I and C, where the point I is an intersection of the carcass and a line extending parallel with the rotational axis through a middle point H of a line segment GC, where the point G is an intersection of the line segment BC and a line extending through the said carcass maximum width point F parallel with the rotational axis.
Claim 12
Independent Claim
251 words
A method of manufacturing a pneumatic radial tire by vulcanizing and forming in a mould, the tire including a pair of sidewalls(5) having bead portions at the respective radially inner ends thereof, a crown portion(6) extending between the sidewalls, a carcass(3) comprising at least one ply including organic fibre cord layers and having its ends turned back about bead wires(l) of the said bead portions, and hard rubber fillers (2) disposed between the said carcass ply and the turned-back portions thereof, characterized in that the said mould comprises a cavity having, in a radial cross-section passing through a line corresponding to the rotational axis of the tire, portions corresponding to the sidewalls of the tire progressively increasing in width and terminating in a foot portion corresponding to a rim, the said foot portion having a width in the direction of the said rotational axis 20-50% wider than the width of the said rim, and the said cavity having, on each side of a plane including an equatorial line of the tire in the said radial cross-section, an outwardly extending profile the centre of the radius of curvature of which is inside the carcass in a radially outer zone from the carcass maximum width position to the said crown portion and an inwardly extending profile continuous with the said outwardly extending profile the centre of the radius of curvature of which is outside the carcass in a radially inner zone from the said carcass maximum width position to the said bead portion.
Claim 13
Independent Claim
251 words
A method of manufacturing a pneumatic radial tire by vulcanizing and forming in a mould, the tire including a pair of sidewalls(5) having bead portions at the respective radially inner ends thereof, a crown portion(6) extending between the sidewalls, a carcass(3) comprising at least one ply including organic fibre cord layers and having its ends turned back about bead wires(l) of the said bead portions, and hard rubber fillers (2) disposed between the said carcass ply and the turned-back portions thereof, characterized in that the said mould comprises a cavity having, in a radial cross-section passing through a line corresponding to the rotational axis of the tire, portions corresponding to the sidewalls of the tire progressively increasing in width and terminating in a foot portion corresponding to a rim, the said foot portion having a width in the direction of the said rotational axis 20-50% wider than the width of the said rim, and the said cavity having, on each side of a plane including an equatorial line of the tire in the said radial cross-section, an outwardly extending profile the centre of the radius of curvature of which is inside the carcass in a radially outer zone from the carcass maximum width position to the said crown portion and an inwardly extending profile continuous with the said outwardly extending profile the centre of the radius of curvature of which is outside the carcass in a radially inner zone from the said carcass maximum width position to the said bead portion.
References Cited (Backward Citations)
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