US4075804A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fire resistant asbestos-free door, panel or building elements, and method of manufacture using unique compositions
Assignee: US PLYWOOD Corp A CORP OF
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Filing: 1975-09-22
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Granted: 1978-02-28
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Expires: 1995-09-22
Abstract
Abstract A fire resistant door, panel or building element is manufactured from unique compositions which are free of asbestos, thereby minimizing the health hazards associated with the manufacture of conventional asbestos-containing fireproof doors, panels or building elements. In essence, the compositions comprise calcium silicates, vermiculite, sisal fibers and fiberglass.
Inventors
- 👤 Herbert E. Zimmerman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:33
CPC Classifications
B; B32; B32B; B32B9/00; B32B9/04; B32B9/043; E; E04; E04B; E04B1/00; E04B1/62; E04B1/92; E04B1/94; B32B25/00; B32B25/16; E04C; E04C2/00; E04C2/02; E04C2/26; E04C2/284; E06; E06B; E06B5/00; E06B5/10; E06B5/16; B32B2262/00; B32B2262/10; B32B2262/101; B32B2264/00; B32B2264/12; B32B2307/00; B32B2307/30; B32B2307/304; B32B2307/306; B32B2307/3065; B32B2419/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
67 words
A fire resistant door comprising a core framed within fire resistant stiles and rails, and wherein said core has veneer sheetings, said core having a composition consisting essentially of by weight calcium silicates in an amount within the range of 78.0 to 88.0 percentage; vermiculite, 7.5 to 10.0 percentage; sisal fibers 0.5 to 5.0 percentage; glass fibers 0.1 to 1.0 percentage; and moisture 2.0 to 15.0 percentage.
Claim 2
Dependent Claim
67 words
A fire resistant door comprising a core framed within fire resistant stiles and rails, and wherein said core has veneer sheetings, said core having a composition consisting essentially of by weight calcium silicates in an amount within the range of 78.0 to 88.0 percentage; vermiculite, 7.5 to 10.0 percentage; sisal fibers 0.5 to 5.0 percentage; glass fibers 0.1 to 1.0 percentage; and moisture 2.0 to 15.0 percentage.
Claim 3
Dependent Claim
36 words
A fire resistant door as in claim 1 wherein said vermiculite has the approximate composition of silicon oxide 39%, magnesium oxide 21%, aluminum oxide 15%, iron oxide 5%, potassium oxide 1%, and water 5 to 9%.
Claim 4
Dependent Claim
20 words
A fire resistant door as in claim 1 wherein the sisal fibers have lengths of about 1 to 2 inches.
Claim 5
Dependent Claim
117 words
Process for the manufacture of 11/2 hour fire test door which comprises positioning a first veneer face on a support, positioning a first semi-precured crossband with adhesive applied to both surfaces on said first veneer, positioning on said first crossband a fire resistant core, said core consisting essentially of 70.0 to 90.0 weight percentage calcium silicates, 4.0 to 15.0 weight percentage vermiculite, 0.5 to 5.0 weight percentage sisal fibers, 0.1 to 1.0 weight percentage fiber glass, and 2.0 to 15.0 weight percentage moisture, then applying to said core a second cross band having adhesive on both surfaces, then applying to said second crossband a cross veneer face, and thereafter pressing and curing at elevated temperatures and pressures.
Claim 6
Dependent Claim
117 words
Process for the manufacture of 11/2 hour fire test door which comprises positioning a first veneer face on a support, positioning a first semi-precured crossband with adhesive applied to both surfaces on said first veneer, positioning on said first crossband a fire resistant core, said core consisting essentially of 70.0 to 90.0 weight percentage calcium silicates, 4.0 to 15.0 weight percentage vermiculite, 0.5 to 5.0 weight percentage sisal fibers, 0.1 to 1.0 weight percentage fiber glass, and 2.0 to 15.0 weight percentage moisture, then applying to said core a second cross band having adhesive on both surfaces, then applying to said second crossband a cross veneer face, and thereafter pressing and curing at elevated temperatures and pressures.
Claim 7
Dependent Claim
54 words
Process for the manufacture of a 11/2 hour fire test door according to claim 4 wherein the step of pressing and curing the door is performed in an autoclave in the temperature range of 100° F to 200° F, at a pressure between 125 psi to 225 psi, for a period between 15-20 hours.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-27 | 1981-08-29 | 1982-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-27 | 1985-08-29 | 1986-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-27 | 1989-08-29 | 1990-02-28 | $7700.00 | Window Closed / Lapsed |