Patent US4668433A successfully refreshed from Google Patents.
Patent US3689964A successfully refreshed from Google Patents.
US3689964A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Machining sintered powder metal
Assignee: KEYSTONE CARBON COMPANY A PA CORP
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Filing: 1971-02-25
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Granted: 1972-09-12
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Expires: 1991-02-25
Abstract
Abstract A method of providing a machined powder metal article, which comprises the steps of: pressing metal powder into a green compact; sintering the green compact in a substantially nonoxidizing atmosphere; substantially impregnating and coating the sintered compact with an aqueous alkali metal silicate solution; and machining the sintered compact, thereby forming a machined article.
Inventors
- 👤 Orville W Reen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:51
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/24; B22F3/26; Y; Y10; Y10S; Y10S29/00; Y10S29/026; Y10S29/031; Y10T; Y10T29/00; Y10T29/49; Y10T29/4998; Y10T29/49982; Y10T428/00; Y10T428/12; Y10T428/12007
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
20 words
A method according to claim 1 wherein said machining of said sintered compact comprises the step of drilling said compact.
Claim 2
Dependent Claim
22 words
A method according to claim 1 including the step of curing said aqueous alkali metal silicate impregnant and coating prior to machining.
Claim 3
Dependent Claim
13 words
A method according to claim 1 wherein said metal powder is stainless steel.
Claim 4
Dependent Claim
19 words
A method according to claim 1 wherein said aqueous alkali metal silicate solution is an aqueous sodium silicate solution.
Claim 5
Dependent Claim
41 words
A method according to claim 1 wherein said metal powder is stainless steel, wherein said aqueous alkali metal silicate solution is an aqueous sodium silicate solution and wherein said machining of said sintered compact comprises the step of drilling said compact.
References Cited (Backward Citations)
US2373405A
Cited
US2419080A
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US3109735A
Cited
US3214287A
Cited
US3290124A
Cited
US3483006A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-12 | 1976-03-13 | 1976-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-12 | 1980-03-13 | 1980-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-12 | 1984-03-13 | 1984-09-12 | $7700.00 | Window Closed / Lapsed |