Patent US3885246A successfully refreshed from Google Patents.
US3885246A
Expired / Lapsed
US
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Retroreflective protective helmet
Assignee: 3M Co
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Filing: 1973-11-05
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Granted: 1975-05-27
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Expires: 1993-11-05
Abstract
Abstract Protective helmets that give a distinctive retrorefelctive signal under wet or dry conditions at night or in other darkened environments are provided by disposing a retroreflective layer covered by a transparent layer over at least a major portion of the outer surface of the helmet.
Inventors
- 👤 Chi Fang Tung
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:51
CPC Classifications
A; A42; A42B; A42B3/00; A42B3/04; A42B3/06; A42B3/061
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
152 words
A PROTECTIVE HELMET COMPRISING A PROTECTIVE SHELL ADAPTED TO BE WORN ON A PERSON''S HEAD; A RETROREFLECTIVE LAYER DISPOSED OVER SUBSTANTIALLY ALL OF THE OUTER SURFACE OF THE PROTECTIVE SHELL, COMPRISING A LAYER OF BINDER MATERIAL AND A MONOLAYER OF TRANSPARENT GLASS MICROSPHERES THAT ARE PARTIALLY EMBEDED IN THE LAYR OF BINDER MATERIAL AND HAVING A COATING OF SPECULAR REFLECIVE MATERIAL ON THEIR EMBEDDED SURFACE; AND A TRANSPARENT SHEET HAVING THE SHAPE OF THE PROTECTIVE SHELL DISPOSED IRECTLY OVER THE RETROREFLECTIVE LAYER, SAID SHEET BEING IN TIGHT FRICTIONAL ENGAGEMENT WITH SAID RETROREFLECTIVE LAYER BUT WITHOUT OPTICAL CONTACT TO THE EXPOSED SURFACS OF THE MICROSPHERES AND BEING ATTACHED TO THE PROTECTIVE SHELL AT LEAST AROUND THE PRIPHERY OF THE RETOREFFECTIVE LAYER SO AS TO PROVIDE AN AIRTIGHT SEALED POCKET BETWEEN THE RETROEFFECTIVE LAYR AND THE TRANSPARENT SHEET, WHEREBY THE RETROREFLECTIVE LAYER RETROREFLECTS LIGHT SHINED AT THE HELMET UNDER EITHER WET OR DRY CONDITIONS.
Claim 2
Dependent Claim
152 words
A PROTECTIVE HELMET COMPRISING A PROTECTIVE SHELL ADAPTED TO BE WORN ON A PERSON''S HEAD; A RETROREFLECTIVE LAYER DISPOSED OVER SUBSTANTIALLY ALL OF THE OUTER SURFACE OF THE PROTECTIVE SHELL, COMPRISING A LAYER OF BINDER MATERIAL AND A MONOLAYER OF TRANSPARENT GLASS MICROSPHERES THAT ARE PARTIALLY EMBEDED IN THE LAYR OF BINDER MATERIAL AND HAVING A COATING OF SPECULAR REFLECIVE MATERIAL ON THEIR EMBEDDED SURFACE; AND A TRANSPARENT SHEET HAVING THE SHAPE OF THE PROTECTIVE SHELL DISPOSED IRECTLY OVER THE RETROREFLECTIVE LAYER, SAID SHEET BEING IN TIGHT FRICTIONAL ENGAGEMENT WITH SAID RETROREFLECTIVE LAYER BUT WITHOUT OPTICAL CONTACT TO THE EXPOSED SURFACS OF THE MICROSPHERES AND BEING ATTACHED TO THE PROTECTIVE SHELL AT LEAST AROUND THE PRIPHERY OF THE RETOREFFECTIVE LAYER SO AS TO PROVIDE AN AIRTIGHT SEALED POCKET BETWEEN THE RETROEFFECTIVE LAYR AND THE TRANSPARENT SHEET, WHEREBY THE RETROREFLECTIVE LAYER RETROREFLECTS LIGHT SHINED AT THE HELMET UNDER EITHER WET OR DRY CONDITIONS.
Claim 3
Dependent Claim
35 words
A protective helmet of claim 1 in which the retroreflective layer is carried on a support sheet that has the shape of the protective shell and is attached over the exterior of the protective shell.
References Cited (Backward Citations)
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Cited
US3190178A
Cited
US3310900A
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US3420597A
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US3245087A
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US3242500A
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US3795435A
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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) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |