Patent US4712868A successfully refreshed from Google Patents.
US4712868A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Expanded retroreflective sheet material
Assignee: 3M Co
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Filing: 1985-09-23
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Granted: 1987-12-15
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Expires: 2005-09-23
Abstract
Abstract Retroreflective sheet material capable of retroreflecting light at high incidence angles is prepared by laminating retroreflective sheeting to a base sheet, slitting the laminated sheet assembly in an array of spaced discontinuous slits, and expanding the laminated sheet assembly so that openings occur at the slits and portions of the laminated sheet assembly between the slits bend out of the plane which they originally occupied.
Inventors
- 👤 Chi F. Tung
- 👤 James C. Coderre
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:03
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/12; G02B5/126; G02B5/128; G02B5/122; G02B5/124; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24273; Y10T428/24298; Y10T428/24306; Y10T428/24314
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
89 words
Retroreflective sheet material comprising retroreflective sheeting laminated to a base sheet, the retroreflective sheeting being selected from (1) sheeting that comprises a monolayer of transparent microspheres and a layer of specularly reflective material underlying the microspheres and 2) sheeting that comprises cube-corner retroreflective elements; the laminated sheet assembly being slit in an array of spaced discontinuous slits; and the laminated sheet assembly being expanded so that openings occur at the slits, and portions of the laminated sheet assembly between the slits bend out of the plane they originally occupied.
Claim 2
Dependent Claim
89 words
Retroreflective sheet material comprising retroreflective sheeting laminated to a base sheet, the retroreflective sheeting being selected from (1) sheeting that comprises a monolayer of transparent microspheres and a layer of specularly reflective material underlying the microspheres and 2) sheeting that comprises cube-corner retroreflective elements; the laminated sheet assembly being slit in an array of spaced discontinuous slits; and the laminated sheet assembly being expanded so that openings occur at the slits, and portions of the laminated sheet assembly between the slits bend out of the plane they originally occupied.
Claim 3
Dependent Claim
28 words
Retroreflective sheet material of claim 1 in which the laminated sheet assembly is covered with a transparent polymeric layer that seals the slit edges of the retroreflective sheeting.
Claim 4
Dependent Claim
23 words
Retroreflective sheet material of claim 2 in which the transparent polymeric layer is continuous and closes the openings that occur at the slits.
Claim 5
Dependent Claim
23 words
Retroreflective sheet material of claim 1 in which the retroreflective sheeting includes a layer of transparent material covering the monolayer of transparent microspheres.
Claim 6
Dependent Claim
19 words
Retroreflective sheet material of claim 1 in which retroreflective sheeting is laminated to both sides of the base sheet.
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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) | 1990-12-14 | 1991-06-15 | 1991-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-12-14 | 1995-06-15 | 1995-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-12-14 | 1999-06-15 | 1999-12-15 | $7700.00 | Window Closed / Lapsed |