US3668031A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making foam core sandwich panel
Assignee: Bethlehem Steel Corp
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Filing: 1970-03-03
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Granted: 1972-06-06
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Expires: 1990-03-03
Abstract
Abstract A method of making a foam core sandwich panel suitable for use in the building industry by spreading two horizontal panels with a polyurethane foamable resin, allowing the resin to expand partially, then bringing the panel sections with their foam faces together sandwich style, to a vertical position and allowing the foam to complete expansion, coalesce and gel in this vertical position.
Inventors
- 👤 Bernard J Bast
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:45
CPC Classifications
B; B32; B32B; B32B15/00; B32B15/04; B32B15/046; B29; B29C; B29C44/00; B29C44/02; B29C44/12; B29C44/1223; B32B21/00; B32B21/04; B32B21/047; B32B27/00; B32B27/06; B32B27/065; B32B5/00; B32B5/18; B32B5/20; E; E04; E04C; E04C2/00; E04C2/02; E04C2/10; E04C2/20; E04C2/205; B29C33/00; B29C33/20; B29L; B29L2007/00; B29L2007/002; B29L2009/00; B32B2266/00; B32B2266/02; B32B2266/0214; B32B2266/0278; B32B2607/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
25 words
The method recited in claim 1 further comprising: e. supplying heat to the panel sections in the range from about 110* F. to 140* F.
Claim 2
Dependent Claim
17 words
The method recited in claim 2 in which said heat is supplied during steps a through d.
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) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |