EP0202925A2
Expired / Lapsed
EP
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A radial tyre for heavy duty
Assignee: Sumitomo Rubber Industries Ltd
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Filing: 1986-05-21
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Granted: —
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Expires: 2006-05-21
Abstract
Abstract A pneumatic radial tyre for heavy duty vehicles such as trucks, buses etc; having an improved reinforcing structure of bead, which can be effectively improved in the durability under very heavy lead conditions and can be recapped two or three times without failure of the base tyre. The tyre, comprises: a radial carcass ply (2) composed of at least one rubber ised metal cord ply; a first metallic cord reinforcing layer (4) disposed at the outside of the turned up portion (2') of the carcass ply (2); and a second fibre cord reinforcing layer (6) secured to the inner surface of the carcass ply main portion. The radially inner portion of the second reinforcing layer (6) is interposed by a given width (LO between the turned up portion (4') of the first reinforcing layer (4) and the main portion of the carcass ply in the bead base portion. The height (h1) of the radially outermost end (2a) of the turned up portion (2') of the carcass ply (2) is higher than the height (h2) of the radially outremost end (4a) of the first reinforcing layer (4).
Inventors
- 👤 Kazuhiko Kawamura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 19:25
CPC Classifications
B; B60; B60C; B60C15/00; B60C15/06; B60C15/0603; B60C15/0607; Y; Y10; Y10T; Y10T152/00; Y10T152/10; Y10T152/10495; Y10T152/10819; Y10T152/10828; Y10T152/10837; Y10T152/10846
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
254 words
1 A radial tyre for heavy duty use comprising: a carcass ply (2) of a substantially radial arrangement, composed of metallic cords of which both ends are turned up around a pair of a circular bead core (3) from the axially inside towards the axially outside of the tyres; characterised in each bead region; a first reinforcing layer (4) composed of at least one metallic cord layer having metallic cords, disposed adjacent to the outside of turned up portion (2) of the carcass ply, and turned up around the bead core (3) from the axially outside towards the axially inside of the tyre; a second reinforcing layer (6) composed of at least one fibre cord layer having fibre cords, disposed along the axially inside of the main portion of the carcass ply (2) and radially extending from the bead base portion at a height h5 to a height h3; the height hl of the radially outermost end of the turned up portion of the carcass ply measured perpendicularly from the bead base, is higher than the height h2 of the radially outermost end of (4a) the first reinforcing layer perpendicular from bead base; the height h4 of the radially inward turned up portion (4b) of the first reinforcing layer measured perpendicularly from the beadbase, is lower than the height h3; and the radially innermost end (6b) of the second reinforcing layer is interposed between the inward turned up portion (4b) of the first reinforcing layer and the main portion (2) of the carcass ply.
Claim 2
Dependent Claim
254 words
1 A radial tyre for heavy duty use comprising: a carcass ply (2) of a substantially radial arrangement, composed of metallic cords of which both ends are turned up around a pair of a circular bead core (3) from the axially inside towards the axially outside of the tyres; characterised in each bead region; a first reinforcing layer (4) composed of at least one metallic cord layer having metallic cords, disposed adjacent to the outside of turned up portion (2) of the carcass ply, and turned up around the bead core (3) from the axially outside towards the axially inside of the tyre; a second reinforcing layer (6) composed of at least one fibre cord layer having fibre cords, disposed along the axially inside of the main portion of the carcass ply (2) and radially extending from the bead base portion at a height h5 to a height h3; the height hl of the radially outermost end of the turned up portion of the carcass ply measured perpendicularly from the bead base, is higher than the height h2 of the radially outermost end of (4a) the first reinforcing layer perpendicular from bead base; the height h4 of the radially inward turned up portion (4b) of the first reinforcing layer measured perpendicularly from the beadbase, is lower than the height h3; and the radially innermost end (6b) of the second reinforcing layer is interposed between the inward turned up portion (4b) of the first reinforcing layer and the main portion (2) of the carcass ply.
Claim 3
Dependent Claim
49 words
A radial tyre for heavy duty according to claim 1, characterised in that the maximum inflated width of the tyre lies at height h6 and the height hl of the turned up portion (2a) of the carcass ply is 0.3 to 0.5 times as high as the height h6.
Claim 4
Dependent Claim
59 words
a radial tyre for heavy duty according to claim 1 or 2 characterised in that the height h2 of the radially outermost end (4a) of the first reinforcing layer in the radial direction is 0.7 to 0.9 times as high as the height hl of the radially outermost end (2a) of the turned up portion of the carcass (2).
Claim 5
Dependent Claim
59 words
a radial tyre for heavy duty according to claim 1, 2 or 3 characterised in that the height h3 of the radially outermost end (6a) of the second reinforcing layer (6) is 0.7 to 3.0 times as high as the height hl of the radially outermost end (2a) of the turned up portion (2) of the carcass ply (2).
Claim 6
Dependent Claim
60 words
a radial tyre for heavy duty according to any of claims 1-4 characterised in that the height h4 of the radially outermost end (4b) of the axially inward turned up portion (4) of the first reinforcing layer (4) is 0.2 to 0.8 times as high as the height h3 of the radially outermost end (2a) of the second reinforcing layer.
Claim 7
Dependent Claim
63 words
a radial tyre for heavy duty according to any one of claims 1-5 characterised in that the cord angle of the 0 0 second reinforcing layer (6) is 30 to 80 with respect to the ply cord of the carcass main portion (2) at the height hl of the radially outermost end (2a) of the turned up portion of the carcass ply (2).
Claim 8
Dependent Claim
48 words
a radial tyre for heavy duty according to any one of claims 1-6 characterised in that the second reinforcing layer (6) is composed of at least one rubberised ply layer having cords embedded therein which cords have 2 a modulus of initial elasticity of 700-to 15000 kgf/mm .
Claim 9
Dependent Claim
149 words
a radial tyre for heavy duty according to any one of claims 1-7 characterised by a bead apex disposed between the main'portion and turned up portion (2) of the carcass ply is composed of two separate rubber stocks (11, 12) (11) being one arranged adjacent to the bead core (3) and between the main portion (2) and turned up portion (2) of the carcass, and composed of a high elasticity rubber compound having a modulus of elasticity of 60 to 150 kgf/cm at 100% elongation and a JIS (A) hardness of 70 t1 90 and; the other (12) being disposed adjacent to the said high elasticity rubber stocks (11) composed of a low elasticity rubber compound having a modulus of elasticity of 10 to 45 kgf/cm at 100% elongation and a JIS (A) hardness of 45 to 65 which is lower than that of the carcass ply coating rubber.
References Cited (Backward Citations)
JPS48100805A
Cited
JPS5211481B2
Cited
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