Patent US4354993A successfully refreshed from Google Patents.
US4354993A
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US
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Method of manufacturing a magnet body
Assignee: US Philips Corp
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Filing: 1977-05-27
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Granted: 1982-10-19
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Expires: 1997-05-27
Abstract
Abstract A method of manufacturing a sintered permanent magnetizable body essentially consisting of a ferrite of the formula MeO.6Fe 2 O 3 , wherein Me is at least one of the metals barium, strontium and lead by adding an acid to a suspension of the powdered ferrite in a liquid which suspension is then supplied to one or more matrices of a press to form a compressed product which is then sintered. As a result of the treatment with acid, the compression time is reduced.
Inventors
- 👤 Franciscus X. N. M. Kools
- 👤 Sytse Strijbos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:49
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/26; C04B35/2683; Y; Y10; Y10S; Y10S264/00; Y10S264/58
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
101 words
In a method of manufacturing a sintered permanent magnetisable body essentially consisting of a ferrite of formula MeO. 6Fe 2 O 3 , wherein Me is at least one of the metals barium, strontium and lead, wherein a suspension of the powdered ferrite in an aqueous liquid is formed, the suspension being compressed while removing the liquid to form a compact product and the compact product thereafter being sintered into a coherent body, the improvement wherein an acid is added to the suspension to dissolve small particles and thereby reduce the time required to compress the suspension into a compact body.
Claim 2
Dependent Claim
101 words
In a method of manufacturing a sintered permanent magnetisable body essentially consisting of a ferrite of formula MeO. 6Fe 2 O 3 , wherein Me is at least one of the metals barium, strontium and lead, wherein a suspension of the powdered ferrite in an aqueous liquid is formed, the suspension being compressed while removing the liquid to form a compact product and the compact product thereafter being sintered into a coherent body, the improvement wherein an acid is added to the suspension to dissolve small particles and thereby reduce the time required to compress the suspension into a compact body.
Claim 3
Dependent Claim
31 words
A method as claimed in claim 1, wherein after the treatment with an acid the suspension is rinsed with water to bring it to a pH of about 1 to 1.5.
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) | 1985-10-18 | 1986-04-19 | 1986-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-18 | 1990-04-19 | 1990-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-18 | 1994-04-19 | 1994-10-19 | $7700.00 | Window Closed / Lapsed |