US3840060A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pneumatic tire
Assignee: Industrie Pirelli SpA
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Filing: 1972-07-19
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Granted: 1974-10-08
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Expires: 1992-07-19
Abstract
Abstract This invention relates to a pneumatic tire of the type having substantially inextensible lateral edges of a reinforced tread band portion, and, therefore, radially inextensible sidewalls. According to the invention, the sidewalls are convexly curved towards each other, i.e., turned towards the tire midplane so that internal pneumatic pressure acting laterally outwardly against said sidewalls simply tends to reduce their degree of convexity thereby placing them under compression. The sidewalls comprise three zones, two at the sidewall extremities and the third midway between the other two, which zones are of reduced bending stiffness relative to the remainder of the sidewall portions.
Inventors
- 👤 G Tangorra
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:18
CPC Classifications
B; B60; B60C; B60C9/00; B60C9/18; B60C9/20; B60C9/22; B60C11/00; B60C11/01; B60C13/00; B60C15/00; B60C15/02; B60C15/024; B60C15/0247; B60C3/00; B60C9/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
186 words
A pneumatic tire comprising a tread having an annular reinforcement which is substantially inextensible in its circumferential and traverse directions, said tread being wider than any other part of the tire, beads adapted to engage bead seats in the wheel rim, and two sidewalls extending from the lateral edges of said tread to said beads, each sidewall having a first zone of reduced bending stiffness adjacent said edges, a second zone of reduced bending stiffness adjacent said beads, and a third zone of reduced bending stiffness intermediate said first and second zone, said sidewalls extending in mutually converging relationship from said first to said third zone of reduced bending stiffness and in mutually diverging relationship from said third to said second zone of reduced bending stiffness, whereby said sidewalls have a configuration convex towards the interior of the tire, the bending stiffness, thicknesses and curvatures of said sidewalls in their several zones being such as to maintain said convexity in the inflated condition of the tire, whereby said sidewalls are constrained between said edges of the tread and said beads and are placed in compression stress.
Claim 2
Dependent Claim
186 words
A pneumatic tire comprising a tread having an annular reinforcement which is substantially inextensible in its circumferential and traverse directions, said tread being wider than any other part of the tire, beads adapted to engage bead seats in the wheel rim, and two sidewalls extending from the lateral edges of said tread to said beads, each sidewall having a first zone of reduced bending stiffness adjacent said edges, a second zone of reduced bending stiffness adjacent said beads, and a third zone of reduced bending stiffness intermediate said first and second zone, said sidewalls extending in mutually converging relationship from said first to said third zone of reduced bending stiffness and in mutually diverging relationship from said third to said second zone of reduced bending stiffness, whereby said sidewalls have a configuration convex towards the interior of the tire, the bending stiffness, thicknesses and curvatures of said sidewalls in their several zones being such as to maintain said convexity in the inflated condition of the tire, whereby said sidewalls are constrained between said edges of the tread and said beads and are placed in compression stress.
Claim 3
Dependent Claim
46 words
A pneumatic tire as in claim 1, characterized in that the ratio between the bending stiffness at least at one of said low stiffness zones of each sidewall and the bending stiffness of the other parts of said sidewall does not exceed a value of 0.6.
Claim 4
Dependent Claim
18 words
A pneumatic tire as in claim 2, characterized in that said ratio is comprised between 0.6 and 0.01.
Claim 5
Dependent Claim
29 words
A pneumatic Tire as in claim 1, characterized in that the various values of bending stiffness are obtained by imparting different thicknesses to the meridian section of each sidewall.
Claim 6
Dependent Claim
27 words
A pneumatic tire as in claim 1, characterized in that the various values of bending stiffness are obtained by using materials having a different modulus of elasticity.
Claim 7
Dependent Claim
68 words
A pneumatic tire as in claim 5, characterized in that said zones of lower bending stiffness are constituted by a compound having a modulus of elasticity, measured at one-tenth of the tensile strength, comprised between 5 and 60 Kg/cm2, while the zones of greater stiffness are constituted by a compound having a modulus of elasticity, measured at one-tenth of the tensile strength, comprised between 20 and 150 Kg/cm2.
Claim 8
Dependent Claim
39 words
A pneumatic tire as in claim 5, characterized in that said zones of greater bending stiffness are constituted by a compound incorporating short fibers of a material having a modulus of elasticity higher than that of the compound itself.
Claim 9
Dependent Claim
26 words
A pneumatic tire as in claim 7, characterized in that said fibers are made of glass and most of them are oriented along a preferred direction.
Claim 10
Dependent Claim
33 words
A pneumatic tire as in claim 1, characterized in that at least in proximity of its joining with each sidewall, said inextensible annular reinforcement has a curvature convexly directed towards the tire inside.
Claim 11
Dependent Claim
51 words
A pneumatic tire as in claim 9, characterized in that the angle comprised between the axis of rotation of the tire and the tangent to the profile of the annular reinforcement in the joining zone between said inextensible annular reinforcement and each of the two sidewalls is between 20* and 60*.
Claim 12
Dependent Claim
64 words
A pneumatic tire as in claim 1, characterized in that said annular reinforcement has a structure comprising at least two layers of textile or metallic cords, said cords being crossed to each other, said layers being stiffened at their lateral edges by means of turn-ups of their skirtings, or by means of inextensible strips of cords arranged in the circumferential direction of the tire.
References Cited (Backward Citations)
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Cited
US3253636A
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US3480065A
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US3464477A
Cited
US3394751A
Cited
US3682221A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |