US3945871A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a tread for the recapping of tires
Assignee: Bridgestone Bandag LLC
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Filing: 1973-09-06
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Granted: 1976-03-23
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Expires: 1993-09-06
Abstract
Abstract A tread for the recapping of tires is provided with a roughened internal surface simultaneously with the shaping of profile on its external surface in a vulcanizing form. The internal surface can be roughened by placing against the body of raw rubber in the form of a latticework, a plate with regularly or irregularly distributed projections or a composite deforming structure. The internal surface of the prefabricated tread can be sealed from the atmosphere by a foil which is applied to the internal surface directly in the form or subsequent to removal of tread from the form.
Inventors
- 👤 Wilhelm Schelkmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:58
CPC Classifications
B; B29; B29D; B29D30/00; B29D30/06; B29D30/52; B29D30/58; B29D2030/582; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1028
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
249 words
A method of producing a circumferentially complete storable tread or a section thereof for use in the recapping of tires, comprising the steps of providing a mold having a bottom surface of an outline complementary to the desired profile of an external surface of the tread; introducing into the mold an effective amount of raw rubber so as to form in the mold a layer having an exposed surface corresponding to the internal surface of the tread and a concealed surface adjacent to the bottom surface of the mold; pressing against said exposed surface of said layer a deforming structure having a plurality of projections and recesses to impart to said exposed surface a complementary configuration and to simultaneously press said layer against the bottom surface of the mold so that said concealed surface assumes said desired profile; converting said layer into a prefabricated tread having a profiled external surface and a configurated internal surface suited for subsequent bonding to a tire to be recapped, including heating said layer; applying a removable layer of impermeable material to said internal surface of said tread to prevent access of the ambient air to said internal surface; and storing said tread prior to the use thereof for recapping for a storage period during which oxidation of the rubber forming said internal surface is prevented by said layer, whereby said internal surface is ready for immediate bonding without roughening to a tire to be recapped upon removal of said layer of impermeable material.
Claim 2
Independent Claim
249 words
A method of producing a circumferentially complete storable tread or a section thereof for use in the recapping of tires, comprising the steps of providing a mold having a bottom surface of an outline complementary to the desired profile of an external surface of the tread; introducing into the mold an effective amount of raw rubber so as to form in the mold a layer having an exposed surface corresponding to the internal surface of the tread and a concealed surface adjacent to the bottom surface of the mold; pressing against said exposed surface of said layer a deforming structure having a plurality of projections and recesses to impart to said exposed surface a complementary configuration and to simultaneously press said layer against the bottom surface of the mold so that said concealed surface assumes said desired profile; converting said layer into a prefabricated tread having a profiled external surface and a configurated internal surface suited for subsequent bonding to a tire to be recapped, including heating said layer; applying a removable layer of impermeable material to said internal surface of said tread to prevent access of the ambient air to said internal surface; and storing said tread prior to the use thereof for recapping for a storage period during which oxidation of the rubber forming said internal surface is prevented by said layer, whereby said internal surface is ready for immediate bonding without roughening to a tire to be recapped upon removal of said layer of impermeable material.
Claim 3
Dependent Claim
14 words
A method as defined in claim 1, wherein said deforming structure is a latticework.
Claim 4
Dependent Claim
16 words
A method as defined in claim 1, wherein said deforming structure consists of several separable sections.
Claim 5
Dependent Claim
21 words
A method as defined in claim 1, wherein said exposed surface of said prefabricated tread has the configuration of sand paper.
Claim 6
Dependent Claim
24 words
A method as defined in claim 1, further comprising the step of evacuating air from the form in the course of said converting step.
Claim 7
Dependent Claim
24 words
A method as defined in claim 1, wherein the recesses and/or projections of the deforming structure have portions of different height, depth and/or width.
Claim 8
Dependent Claim
18 words
A method as defined in claim 1, wherein said internal surface of said prefabricated tread comprises undercut projections.
Claim 9
Dependent Claim
50 words
A method as defined in claim 1, wherein said applying step includes placing a deformable protective sheet over said internal surface immediately following said converting step; and deforming said protective sheet so as to closely follow the configuration of said internal surface and seal the latter from the ambient air.
Claim 10
Dependent Claim
56 words
A method as defined in claim 1, wherein said applying step includes placing a deformable protective sheet over said internal surface prior to said pressing step; and wherein said protective sheet is deformed during said pressing step so as to closely follow the configuration of said internal surface and seal the latter from the ambient air.
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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) | 1979-03-23 | 1979-09-22 | 1980-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-23 | 1983-09-22 | 1984-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-23 | 1987-09-22 | 1988-03-23 | $7700.00 | Window Closed / Lapsed |