EP0728598A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Tyre with a reinforced belt band
Assignee: Pirelli Tyre SpA
•
Filing: 1996-02-23
•
Granted: —
•
Expires: 2016-02-23
Abstract
Abstract The described tyre, particularly adapted for cars, is provided with belt strips (7, 8) each consisting of a first and a second series of cords (7a, 7b, 8a, 8b) made of different materials, alternated with each other according to a preestablished sequence. The cords (7b, 8b) of the second series, made of aramid for example, cooperate with those of the first series (7a, 8a), made of steel, to withstand tensile stresses in the longitudinal direction. Conversely, the cords (7b, 8b) of aramid have a greater compliance than the steel cords (7a, 8a) towards the compressive stresses. The elastomer incorporating the cords (7a, 7b, 8a, 8b) is filled with reinforcing fibres, short aramid fibres or aramid pulp for example, and has a modulus of elasticity included between 15 and 50 MPa, to prevent breakages of the metallic cords (7a, 7b) by effect of buckling loads.
Inventors
- 👤 Maurizio Boiocchi
- 👤 Gurdev Orjela
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 00:58
CPC Classifications
B; B60; B60C; B60C9/00; B60C9/18; B60C9/1821; B60C9/20; B60C9/2003; B60C9/2009; B60C2009/2012; B60C2009/2029; B60C9/22; B60C2009/2219; Y; Y10; Y10T; Y10T152/00; Y10T152/10; Y10T152/10495; Y10T152/10513; Y10T152/10765; Y10T152/10783; Y10T152/1081
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
160 words
A tyre having a reinforced belt band, comprising: - at least one carcass ply (2) having opposite circumferential edges turned up about corresponding bead cores (3), each arranged close to a circumferential inner edge of the tyre; - at least one belt strip (7, 8) circumferentially wrapped about the carcass ply (2) and comprising a layer of elastomeric material incorporating a first series of tough cords (7a, 8a) and a second series of tough cords alternated (7b, 8b) with the cords (7a, 8a) of the first series according to a predetermined sequence, the cords belonging to at least one of said first and second series having a resistance for tensile strain greater than their resistance for compressive strain; - a tread band (6) circumferentially wrapped about said belt strip (7, 8), characterized in that said layer of elastomeric material is filled with fibrous reinforcing means to give the elastomeric material a modulus of elasticity included between 15 and 50 MPa.
Claim 2
Dependent Claim
18 words
A tyre according to claim 1, characterized in that said fibrous reinforcing means consists of reinforcing aramid fibres.
Claim 3
Dependent Claim
79 words
A tyre according to claim 1, characterized in that said reinforcing fibres are oriented according to a preferential direction forming an angle of a value included between 0° and 90° to the longitudinal extension of the cords, (7a, 8a, 7b, 8b), so as to give the belt strip a desired ratio value between the moduli of elasticity detectable in the direction of the longitudinal extension of the cords (7a, 8a, 7b, 8b) and in a direction perpendicular thereto, respectively.
Claim 4
Dependent Claim
27 words
A tyre according to claim 2, characterized in that said reinforcing fibres are incorporated in the elastomeric material in an amount included between 1 and 10 phr.
Claim 5
Dependent Claim
28 words
A tyre according to claim 1, characterized in that said elastomeric material filled with fibrous reinforcing means has a coefficient of hysteresis loss included between 0.06 and 0.2.
Claim 6
Dependent Claim
22 words
A tyre according to claim 1, characterized in that said elastomeric material contains sulphur in an amount between 2 and 6 phr.
Claim 7
Dependent Claim
25 words
A tyre according to claim 1, characterized in that said elastomeric material contains a bodying resin in an amount included between 0.5 and 3 phr.
Claim 8
Dependent Claim
25 words
A tyre according to claim 1, characterized in that said elastomeric material comprises a methylene donor in an amount included between 1 and 8 phr.
Claim 9
Dependent Claim
59 words
A tyre according to claim 1, characterized in that it comprises a first belt strip (7) wrapped about the carcass ply (2) and a second belt strip (8) wrapped about the first belt strip (7), each of said belt strips (7, 8) comprising a first series and a second series of cords (7a, 7b, 8a, 8b) of different materials.
Claim 10
Dependent Claim
34 words
A tyre according to claim 9, characterized in that the cords (7a, 8a) of the first series are made of steel and the cords (7b, 8b) of the second series are made of aramid.
Claim 11
Dependent Claim
26 words
A tyre according to claim 10, characterized in that the cords (7b, 8b) belonging to the second series have a dTex included between 1000 and 4000.
Claim 12
Dependent Claim
30 words
A tyre according to claim 10, characterized in that each cord (7b, 8b) belonging to the second series is disposed intermediate two cords (7a, 8a) belonging to the first series.
Claim 13
Dependent Claim
31 words
A tyre according to claim 10, characterized in that each cord (7a, 8a) belonging to the first series comprises two strands twisted together, each strand being comprised of four elementary wires.
Claim 14
Dependent Claim
35 words
A tyre according to claim 9, characterized in that the cords (7a, 8a, 7b, 8b) of the first and second series are distributed according to a thickness or density included between 50 and 150 threads/dm.
Claim 15
Dependent Claim
38 words
A tyre according to claim 9, characterized in that the cords (7a, 8a, 7b, 8b) of the first and second series take a volume included between 20% and 80% of the overall volume of the corresponding belt strip.
Claim 16
Dependent Claim
50 words
A tyre according to claim 9, characterized in that it further comprises at least one auxiliary belt strip (9) circumferentially wrapped about the second belt strip (8) and comprising cords of heat-shrinkable material disposed according to an inclination included between 0° and 10° to the circumferential direction of the tyre.
Claim 17
Dependent Claim
61 words
A tyre according to claim 16, characterized in that said auxiliary belt strip (9) comprises at least two ribbon-like portions each overlapping corresponding side edges of the first and second belt strips (7, 8), each of said ribbon-like portions overlapping the second belt strip (8) by an amount included between 10% and 30% of the width of this second strip (8).
Claim 18
Dependent Claim
46 words
A tyre according to claim 9, characterized in that the modulus of elongation under tension of the cords (7b, 8b) of the second series is at least equal to 50% of the modulus of elongation under tension of the cords (7a, 8a) of the first series.
Claim 19
Dependent Claim
29 words
A tyre according to claim 9, characterized in that the ratio between the cord quantities belonging to said first and second series respectively is included between 0.2 and 0.8.
Claim 20
Dependent Claim
37 words
A tyre according to claim 9, characterized in that the cords (7a, 8a) belonging to the first series are made of steel and the cords (7b, 8b) belonging to the second series are made of glass fibre.
References Cited (Backward Citations)
FR1374817A
Cited
DE1937684A1
Cited
US3772130A
Cited
FR2263898A1
Cited
US4073330A
Cited
FR2344412A1
Cited
EP0320705A2
Cited
US4949770A
Cited
EP0329589A2
Cited
US4871004A
Cited
US5351735A
Cited
JPH06115307A
Cited
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.