US3647616A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stiffener and process for stiffening flexible sheet material
Assignee: USM Corp
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Filing: 1970-02-06
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Granted: 1972-03-07
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Expires: 1990-02-06
Abstract
Abstract STIFFENER AND STIFFENING PROCESS FOR FLEXIBLE SHEET MATERIAL, PARTICULARLY FOR PARTS OF SHOE UPPERS IN WHICH THE NOVEL STIFFENER IS A NORMAL STIFF, RESILIENT CROSS-LINKED CURED POLYURETHANE SHEET WITH A LAYER OF HEAT-ACTIVATABLE ADHESIVE ON IS SURFACE. THE STIFFENER IS HEATED TO ACTIVATE THE ADHESIVE AND SOFTEN THE POLYURETHANE SHEET TO A RUBBERY STATE, THE HEATED STIFFENER IS PRESSED AGAINST A SHEET MATERIAL TO ESTABLISH ADHESIVE ENGAGEMENT AND THE ASSEMBLY OF SHEET MATERIAL AND STIFFENER IS SHAPED AND COOLED TO RESILIENT, SHAPE-RETAINING CONDITION.
Inventors
- 👤 John C Zemlin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 00:23
CPC Classifications
A; A43; A43B; A43B23/00; A43B23/08; A43B23/16; A43B23/17; A43D; A43D11/00; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1043; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12028; Y10T428/12063; Y10T428/12139; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31551; Y10T428/31573; Y10T428/31576
Claims Analysis
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References Cited (Backward Citations)
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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) | 1975-03-07 | 1975-09-06 | 1976-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-07 | 1979-09-06 | 1980-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-07 | 1983-09-06 | 1984-03-07 | $7700.00 | Window Closed / Lapsed |