US3984796A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic hoists
Assignee: Individual
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Filing: 1975-08-22
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Granted: 1976-10-05
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Expires: 1995-08-22
Abstract
Abstract An electro-magnet or chuck for lifting scrap metallic particles, comprising a housing essentially of magnetic material. Enclosed are a plurality of spirally wound, superposed coils. Each coil has a central portion which is wound as a bimetal, that is, one winding having magnetic properties, such as an iron winding, and the other, non-magnetic, such as an aluminum winding in series with an outer winding portion of non-magnetic turns. The housing has an annular bottom portion of durable non-magnetic material, such as stainless steel, which is magnetically bridged by scrap magnetic particles being lifted.
Inventors
- 👤 George W. Frampton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:23
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/06; H01F7/20; H01F7/206
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
112 words
A lifting electro-magnet comprising a cylindrical housing substantially of magnetic material, a plurality of spirally wound, superposed coils concentric with said cylindrical housing and encased in insulation, each of said coils having a central portion in which the windings are bimetallic with one winding having magnetic properties and the other having non-magnetic properties, each of said coils having an outer portion solely of non-magnetic windings insulated from each other and connected in series with the outermost non-magnetic winding of said central portion, the bottom of said housing having an outer annular portion of non-magnetic material located essentially underneath said non-magnetic windings and which is bridged by scrap magnetic lifted by said electomagnet.
Claim 2
Dependent Claim
112 words
A lifting electro-magnet comprising a cylindrical housing substantially of magnetic material, a plurality of spirally wound, superposed coils concentric with said cylindrical housing and encased in insulation, each of said coils having a central portion in which the windings are bimetallic with one winding having magnetic properties and the other having non-magnetic properties, each of said coils having an outer portion solely of non-magnetic windings insulated from each other and connected in series with the outermost non-magnetic winding of said central portion, the bottom of said housing having an outer annular portion of non-magnetic material located essentially underneath said non-magnetic windings and which is bridged by scrap magnetic lifted by said electomagnet.
Claim 3
Dependent Claim
15 words
A lifting electromagnet as recited in claim 1 wherein said non-magnetic windings are of aluminum.
Claim 4
Dependent Claim
26 words
A lifting electromagnet as recited in claim 1 wherein a central cylindrical well is provided in said housing in which terminals for said coils are located.
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) | 1979-10-05 | 1980-04-05 | 1980-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-05 | 1984-04-05 | 1984-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-05 | 1988-04-05 | 1988-10-05 | $7700.00 | Window Closed / Lapsed |