US3871026A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ceramic reinforced helmet
Assignee: Feldmuehle Anlagen und Produktion GmbH
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Filing: 1972-12-15
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Granted: 1975-03-18
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Expires: 1992-12-15
Abstract
Abstract A steel helmet may be strengthened greatly by coating its outer, generally convex face with a layer of ceramic particles deposited on the steel at a temperature above their sintering temperature, as by flame spraying or plasma spraying, if the ceramic material has a hardness value of at least 8 on the Mohs scale. Chromium sesquioxide when integrally bonded to the steel of the helmet is strongest at light weight, but aluminum oxide and the carbides of boron, titanium, or silicon perform almost as well. The laminar helmet shell resists projectiles that would pass through an equal weight of steel alone.
Inventors
- 👤 Erhard Dorre
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 02:15
CPC Classifications
F; F41; F41H; F41H1/00; F41H1/04; F41H1/06; F41H5/00; F41H5/02; F41H5/04; F41H5/0414; F41H5/0421; Y; Y10; Y10S; Y10S428/00; Y10S428/911
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
85 words
A HELMET COMPRISING A LAMINAR SHELL OF SUBSTANTIALLY UNIFORM THICKNESS AND OF ARCUATE SECTION IN THREE PLANES PERPENDICULAR TO EACH OTHER, SAID SHELL INCLUDING A METALLIC BASE LAYER HAVING AN OUTER, SUBSTANTIALLY CONVEX FACE AND AN INNER, SUBSTANTIALLY CONCAVE FACE, AND AN OUTER LAYER OF CERAMIC MATERIAL ON SAID CONVEX FACE, SAID OUTER LAYER ESSENTIALLY CONSISTING OF CRYSTALLINE, NON-METALLIC PARTICLES HAVING A HARDNESS VALUE OF AT LEAST 8 ON THE MOHS SCALE AND BEING INTEGRALLY THERMALLY BONDED TO EACH OTHER AND TO SAID BASE LAYER.
Claim 2
Dependent Claim
85 words
A HELMET COMPRISING A LAMINAR SHELL OF SUBSTANTIALLY UNIFORM THICKNESS AND OF ARCUATE SECTION IN THREE PLANES PERPENDICULAR TO EACH OTHER, SAID SHELL INCLUDING A METALLIC BASE LAYER HAVING AN OUTER, SUBSTANTIALLY CONVEX FACE AND AN INNER, SUBSTANTIALLY CONCAVE FACE, AND AN OUTER LAYER OF CERAMIC MATERIAL ON SAID CONVEX FACE, SAID OUTER LAYER ESSENTIALLY CONSISTING OF CRYSTALLINE, NON-METALLIC PARTICLES HAVING A HARDNESS VALUE OF AT LEAST 8 ON THE MOHS SCALE AND BEING INTEGRALLY THERMALLY BONDED TO EACH OTHER AND TO SAID BASE LAYER.
Claim 3
Dependent Claim
27 words
A helmet as set forth in claim 1, wherein the material of said base layer is alloy steel having a tensile strength of at least 100 kp/mm2.
Claim 4
Dependent Claim
28 words
A helmet as set forth in claim 1, wherein the material of said base layer is an aluminum alloy having a tensile strength of at least 40 kp/mm2.
Claim 5
Dependent Claim
24 words
A helmet as set forth in claim 1, wherein said ceramic material is aluminum oxide, chromium sesquioxide, boron carbide, titanium carbide, or silicon carbide.
Claim 6
Dependent Claim
42 words
A helmet as set forth in claim 4, wherein said outer layer includes a plurality of portions offset from each other, the devise further comprising at least on rib of metallic material extending outward from said convex face and separating said portions.
Claim 7
Dependent Claim
48 words
A helmet as set forth in claim 4, further comprising a liner in said shell dimensioned conformingly to receive the top of a human head, and a chin strap fastened to said shell for securing the latter to said head when the head is received in said liner.
Claim 8
Dependent Claim
27 words
A helmet as set forth in claim 6, wherein the material of said base layer is alloy steel having a tensile strength of at least 100 kp/mm2.
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) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |