Patent US3594492A successfully refreshed from Google Patents.
US3594492A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pipe-type cable systems with reduced ac losses
Assignee: General Cable Corp
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Filing: 1969-09-30
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Granted: 1971-07-20
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Expires: 1989-09-30
Abstract
Abstract A magnetic, low-loss liner in a metal pipe reduces the AC loss of high-voltage electrical cable enclosed within the pipe; or the cable in the pipe can be wrapped with a sheet or tapes of the magnetic low-loss material. Tapes used for the purpose can be plastic with suitable metal, such as ferromagnetic material of high permeability distributed through the plastic.
Inventors
- 👤 George Bahder
- 👤 Carlos Katz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:24
CPC Classifications
H; H01; H01B; H01B9/00; H01B9/02; H01B7/00; H01B7/17; H01B7/18; H01B7/26; H01B9/06; H01B9/0611
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
122 words
An electrical cable system for transmitting alternatingcurrent when the cable is enclosed in a pipe, including a group of individually insulated conductors extending side by side, and a special magnetic shield surrounding at least three-quarters of the circumference of the group, the shield being made of material having high permeability and low loss, the magnetic shield having a reluctance along its circumference lower than 5 X 107 1/H per foot of the cable system, an electrical resistance in the direction of the length of the cable system higher than 10 4 ohms per foot of the cable system, and an electrical resistance in the direction of the radius of the cable system greater than 1 ohm per foot of the cable system.
Claim 2
Dependent Claim
122 words
An electrical cable system for transmitting alternatingcurrent when the cable is enclosed in a pipe, including a group of individually insulated conductors extending side by side, and a special magnetic shield surrounding at least three-quarters of the circumference of the group, the shield being made of material having high permeability and low loss, the magnetic shield having a reluctance along its circumference lower than 5 X 107 1/H per foot of the cable system, an electrical resistance in the direction of the length of the cable system higher than 10 4 ohms per foot of the cable system, and an electrical resistance in the direction of the radius of the cable system greater than 1 ohm per foot of the cable system.
Claim 3
Dependent Claim
80 words
The electrical cable system described in claim 1 characterized by the magnetic shield having a reluctance along its circumference lower than 5 X 107 1/H per foot of the cable system, an electrical resistance in the direction of the length of the cable system highe r than 10 4 ohms per foOt of the cable system, and an electrical resistance in the direction of the radius of the cable system greater than 1 ohm per foot of the cable system.
Claim 4
Dependent Claim
35 words
The electrical cable system described in claim 1 characterized by the special magnetic shield being wrapped around the outside of the group of insulated conductors, and a skid wire over the outside of the shield.
Claim 5
Dependent Claim
21 words
The electrical cable system described in claim 1 characterized by the individual conductors being wrapped together by the special magnetic shield.
Claim 6
Dependent Claim
81 words
The electrical cable system described in claim 1 characterized by there being three conductors in the group and each of which has a conductor shield, an insulating layer over the conductor shield, an insulation shield covering the outside of the insulation, moisture protection means outside of the insulation shield, the special magnetic shield extending around the full circumference of the group of conductors outside of the moisture protection means, and a skid wire over the outside of the special magnetic shield.
Claim 7
Dependent Claim
52 words
The electrical cable system described in claim 5 characterized by the special magnetic shield comprising tapes made of plastic material with metal distributed through the plastic, the metal distribution including metal that is oriented so that the projections thereof on the inner surface of the tape cover the entire inner surface thereof.
Claim 8
Dependent Claim
104 words
The electrical cable system described in claim 4 characterized by the special magnetic shield being a helically wound layer of flexible tape made of plastic material having two rows of flexible rods therein with the rods extending lengthwise of the tape and with the rods of one row in staggered relation to the rods of the other row, all of the rods being generally parallel to one another and the rods of each row being spaced from one another transversely of the tape, and the rods of one row being of a diameter greater than the spacing of the rods of the other row.
Claim 9
Dependent Claim
102 words
The electrical cable system described in claim 4 characterized by the special magnetic shield being a helically wound layer of flexible tape made of plastic material having two rows of plates therein with the plates extending lengthwise of the tape and with the plates of one row in staggered relation to the plates of the other row, all of the plates being generally parallel to one another and the plates of each row being spaced from one another transversely of the tape, the plates of one row being of a width greater than the spacing of the plates of the other row.
Claim 10
Dependent Claim
33 words
The electrical cable system described in claim 4 characterized by the special magnetic shield being a helically wound layer of flexible tape made of plastic material having ferromagnetic material dispersed throughout the plastic.
Claim 11
Dependent Claim
20 words
The electrical cable system described in claim 4 characterized by the special magnetic shield being made of flexible magnetic tape.
Claim 12
Dependent Claim
18 words
The electrical cable system described in claim 10 characterized by the magnetic tape being intercalated with metal tape.
Claim 13
Dependent Claim
48 words
The electrical cable system described in claim 4 characterized by the special magnetic shield being a helically wound layer of flexible metal tape with the metal corrugated and the corrugations extending transversely of the tape, and with layers of plastic bonded to the surfaces of the corrugated metal.
Claim 14
Dependent Claim
49 words
The electrical cable system described in claim 4 characterized by the special magnetic shield being made of flexible magnetic tape, a metal pipe in which the cable is enclosed, and a continuous strip of highly conductive metal connecting the shield to the pipe in which the cable is enclosed.
Claim 15
Dependent Claim
49 words
The electrical cable system described in claim 1 characterized by a metal pipe in which the cable is enclosed, the special magnetic shield being a liner in the pipe in contact with the inside surface of the pipe and extending around substantially the entire circumferential extent of said surface.
Claim 16
Dependent Claim
96 words
An electrical cable system enclosure including a metal pipe, And a liner in the pipe made of metal having higher permeability and lower loss than the metal pipe the liner having a reluctance along its circumference lower than 5 X 107 1/H per foot of the cable system, an electrical resistance in the direction of the length of the cable system higher than 10 4 ohms per foot of the cable system, and an electrical resistance in the direction of the radius of the cable system greater than 1 ohm per foot of the cable system.
Claim 17
Dependent Claim
96 words
An electrical cable system enclosure including a metal pipe, And a liner in the pipe made of metal having higher permeability and lower loss than the metal pipe the liner having a reluctance along its circumference lower than 5 X 107 1/H per foot of the cable system, an electrical resistance in the direction of the length of the cable system higher than 10 4 ohms per foot of the cable system, and an electrical resistance in the direction of the radius of the cable system greater than 1 ohm per foot of the cable system.
Claim 18
Dependent Claim
22 words
The electrical cable system enclosure described in claim 15 characterized by the liner being an inner pipe enclosed in the first pipe.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-19 | 1975-01-18 | 1975-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-19 | 1979-01-18 | 1979-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-19 | 1983-01-18 | 1983-07-20 | $7700.00 | Window Closed / Lapsed |