US3856601A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of retreading vehicle tires
Assignee: Bridgestone Bandag LLC
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Filing: 1973-04-03
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Granted: 1974-12-24
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Expires: 1993-04-03
Abstract
Abstract Retreading of vehicle tires is accomplished by forming an assembly consisting essentially of a tire carcass having a circumferential face, profiled tread means of elastomeric material superimposed upon the circumferential face and a bonding material between the carcass and the tread means. The assembly is confined in a flexible fluid-tight envelope, the interior of the envelope is exhausted of at least the major portion of entrapped air, and a pressure differential is established between the interior and the exterior of the envelope in a sense exerting pressure upon the latter and expelling residual air confined between the circumferential face and tread means. The assembly is then vulcanized for permanently bonding the tread means to the circumferential face.
Inventors
- 👤 W Schelkmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 03:24
CPC Classifications
B; B29; B29D; B29D30/00; B29D30/06; B29D30/52; B29D30/54; B29D30/542; B29D30/58; B29D2030/582; Y; Y10; Y10S; Y10S156/00; Y10S156/909; Y10S425/00; Y10S425/812
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
189 words
In a method of retreading vehicle tires, the first step of forming an assembly consisting essentially of a tire carcass having a circumferential face, tread means of elastomeric material superimposed upon said circumferential face and provided with relatively deep spaced profiles, and a bonding material between said carcass and said tread means; the second step of confining said assembly in a fluid-tight flexible envelope which overlies said profiles in close abutment with the edges of said profile; the third step of establishing a pressure drop in direction from the exterior to the interior of said envelope so that the same is displaced into the recesses between respective ones of said spaced profiles down to the lowest base regions of the latter so as to exert at such base regions a substantially uniform pressure upon said tread means; the fourth step of venting gaseous fluid entrapped in the respective base region between said profile and said envelope to the exterior of the latter; and the fifth step of vulcanizing said assembly for permanently bonding said tread means to said carcass while said envelope exerts said pressure upon said tread means.
Claim 2
Dependent Claim
189 words
In a method of retreading vehicle tires, the first step of forming an assembly consisting essentially of a tire carcass having a circumferential face, tread means of elastomeric material superimposed upon said circumferential face and provided with relatively deep spaced profiles, and a bonding material between said carcass and said tread means; the second step of confining said assembly in a fluid-tight flexible envelope which overlies said profiles in close abutment with the edges of said profile; the third step of establishing a pressure drop in direction from the exterior to the interior of said envelope so that the same is displaced into the recesses between respective ones of said spaced profiles down to the lowest base regions of the latter so as to exert at such base regions a substantially uniform pressure upon said tread means; the fourth step of venting gaseous fluid entrapped in the respective base region between said profile and said envelope to the exterior of the latter; and the fifth step of vulcanizing said assembly for permanently bonding said tread means to said carcass while said envelope exerts said pressure upon said tread means.
Claim 3
Dependent Claim
53 words
In a method as defined in claim 1, wherein said tread means comprises a plurality of tread segments positioned on said circumferential face in abutting relationship; and further comprising the step of bonding said tread segments to one another in the respective area of abutment prior to confining said assembly in said enclosure.
Claim 4
Dependent Claim
23 words
In a method as defined in claim 2, wherein said additional step comprises subjecting said areas to the action of a high-frequency field.
Claim 5
Dependent Claim
63 words
In a method as defined in claim 1, wherein the step of vulcanizing comprises accommodating said assembly and envelope in an autoclave, and mounting them on a mounting rack in said autoclave; and wherein said fourth step comprises connecting the interior of said envelope via a conduit in said mounting rack with a chamber which is fluid-tightly sealed with reference to said autoclave.
Claim 6
Dependent Claim
20 words
In a method as defined in claim 4; and further comprising the step of regulating the pressure in said autoclave.
Claim 7
Dependent Claim
60 words
In a method as defined in claim 1, wherein the step of vulcanizing comprises accommodating said assembly and envelope in an autoclave; and said fourth step comprises introducing into said autoclave air at a pressure of between substantially 1-2 atmospheres overpressure; and said step of vulcanizing further comprises subsequently replacing said air with hot liquid at substantially 5 atmospheres overpressure.
Claim 8
Dependent Claim
46 words
In a method as defined in claim 1, wherein the step of vulcanizing comprises accommodating said assembly and envelope in an autoclave; and wherein said fourth step comprises introducing into said autoclave a pressure medium having a specific gravity corresponding substantially to that of said assembly.
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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) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |