US4601753A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Powdered iron core magnetic devices
Assignee: General Electric Co
•
Filing: 1985-09-20
•
Granted: 1986-07-22
•
Expires: 2005-09-20
Abstract
Abstract A compacted powdered iron core utilizes iron powder in the 0.002 to 0.006 mean particle size range which is firt coated with an alkali metal silicate and then overcoated with a silicone resin polymer. The treated powder is compressed to approximately 94% of theoretical density and then annealed at approximately 600° C. This results in a core component characterized by overall core losses as low as in conventional laminated cores in A.C. operation.
Inventors
- 👤 Trasimond A. Soileau
- 👤 Lawrence W. Speaker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:22
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/02; H01F41/0206; H01F41/0246; H01F3/00; H01F3/08; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12181; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993; Y10T428/2995
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
53 words
Treated iron powder suitable for compaction, said powder comprising: iron powder consisting of iron particles having a coating of an alkali metal silicate and an overcoating of a high temperature polymer selected from the group consisting of silicones, polyimides, fluorocarbons and acrylics, said coating and overcoating being effective for providing insulation between particles.
Claim 2
Dependent Claim
53 words
Treated iron powder suitable for compaction, said powder comprising: iron powder consisting of iron particles having a coating of an alkali metal silicate and an overcoating of a high temperature polymer selected from the group consisting of silicones, polyimides, fluorocarbons and acrylics, said coating and overcoating being effective for providing insulation between particles.
Claim 3
Dependent Claim
21 words
Treated iron powder as in claim 1 wherein the powder prior to treatment consists of particles sized less than 0.05 inch.
Claim 4
Dependent Claim
16 words
Treated iron powder as in claim 2 wherein the high temperature polymer is a silicone resin.
Claim 5
Dependent Claim
28 words
Treated iron powder as in claim 2 wherein the mean particle size of the iron powder prior to treatment is in the range of 0.002 to 0.006 inch.
Claim 6
Dependent Claim
28 words
Treated iron powder as in claim 2 wherein at least 70% by weight of the particles prior to treatment are in the range of 0.001 to 0.008 inch.
Claim 7
Dependent Claim
34 words
Treated iron powder as in claim 3 wherein total thickness of the silicate coating and silicone overcoating on a particle is in the range from about 1/2% to about 11/2% of the particle size.
Claim 8
Dependent Claim
24 words
Treated iron powder as in claim 3 wherein the alkali metal silicate is potassium silicate and the silicone resin is a polymethyl phenyl siloxane.
References Cited (Backward Citations)
US3245841A
Cited
US3917976A
Cited
US3725521A
Cited
US4177089A
Cited
US4227166A
Cited
SU765891A1
Cited
JPS5585602A
Cited
JPS55130103A
Cited
US4543208A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-07-21 | 1990-01-20 | 1990-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-21 | 1994-01-20 | 1994-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-21 | 1998-01-20 | 1998-07-22 | $7700.00 | Window Closed / Lapsed |