US3727670A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Leachable ceramic cores
Assignee: American Lava Corp
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Filing: 1971-05-27
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Granted: 1973-04-17
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Expires: 1991-05-27
Abstract
Abstract Ceramic cores having at least sufficient zinc oxide to provide essential continuity throughout the structure are provided. Such cores are included in metal castings from which they are leached under acidic or alkaline conditions to provide cavities within the castings.
Inventors
- 👤 J Bailey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:38
CPC Classifications
B; B22; B22C; B22C9/00; B22C9/10; B22C9/105; B22D; B22D29/00; B22D29/001; B22D29/002
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
20 words
In the process of claim 1 the step of leaching zinc oxide in hot 10 to 20 percent aqueous acid.
Claim 2
Dependent Claim
15 words
The process of claim 1 in which leaching is with 33 percent aqueous potassium hydroxide.
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) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |