# US 8,772,639 B2 · Maintenance of electric cables by self-repairing

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 8,772,639 B2
- Document ID: US8772639B2
- Status: Granted
- Kind: B2
- Application number: 13/381,414
- Filed: 2010-06-29
- Published: 2012-05-03
- Granted: 2014-07-08
- Earliest claimed: 2009-06-30
- Assignees: Electricite de France
- Applicants: Yves Bertrand; Céline Martin; Gérard Mortha
- Inventors: Yves Bertrand; Céline Martin; Gérard Mortha
- Web page: https://patentgrep.com/patent/US8772639B2

## CPC

- H02G 1/16: for repairing insulation or armouring of cables
- H02G 15/20: Cable fittings for cables filled with or surrounded by gas or oil (H02G15/34 takes precedence)
- H02G: INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES

## Abstract

A method is provided for maintaining an electric cable, said electric cable comprising at least one electric conductor surrounded by an outer sheath, said outer sheath containing an insulating oil distributed around said electric conductor, such as a fluid-oil cable or an oil-filled cable. A drying oil, selected so as to solidify upon contacting the air, is added to the oil of the cable for sealing off any accidental oil leak through an outer sheath of the electric cable.

## Claims

### Claim 1

A method of maintenance of an electric cable, said cable comprising:
at least one electric conductor;
an outer sheath surrounding said electric conductor;
an insulating oil contained in said outer sheath and distributed around said electric conductor,
the method comprising the steps of:
selecting a drying additive in order to solidify upon contacting the air, and
adding a drying additive to the insulating cable oil, in a proportion chosen for sealing off any oil leak through the outer sheath.

### Claim 2 (depends on 1)

The method of claim 1, wherein the drying additive polymerizes upon contacting dioxygen.

### Claim 3 (depends on 1)

The method of claim 1, wherein, said electric cable being connected to at least one oil tank, the drying additive is added to the insulating cable oil in said oil tank.

### Claim 4 (depends on 3)

The method of claim 3, wherein said cable is buried while said tank is placed so as to be directly accessible without digging up.

### Claim 5 (depends on 1)

The method of claim 1, wherein the insulating cable oil is kept under pressure in said outer sheath.

### Claim 6

A self-repairing electric cable device comprising:
at least one electric conductor,
an outer sheath arranged around said electric conductor, said outer sheath containing an insulating oil distributed around said electric conductor, a composition of the insulating cable oil comprising at least one drying additive, a proportion of the drying additive in the composition of the cable oil being chosen for sealing off a possible oil leak through the outer sheath.

### Claim 7 (depends on 6)

The device according to claim 6, wherein a drying additive composition comprises a linseed oil.

### Claim 8 (depends on 6)

The device according to claim 6, wherein a drying additive composition comprises a China wood oil.

### Claim 9 (depends on 6)

The device according to claim 6, wherein the proportion of drying additive in the composition of the insulating cable oil is comprised between 5% and 50%.

### Claim 10 (depends on 9)

The device according to claim 9, wherein said proportion of drying additive is comprised between 10% and 30%.

### Claim 11 (depends on 6)

The device according to claim 6, wherein the composition of the insulating cable oil further comprises a polymerization catalyst, for promoting and/or accelerating polymerization of the drying additive.

### Claim 12 (depends on 11)

The device according to claim 11, wherein a polymerization catalyst composition comprises a cobalt salt.

### Claim 13 (depends on 11)

The device according to claim 11, wherein a proportion of said polymerization catalyst in the composition of the insulating cable oil is less than 5%.

### Claim 14 (depends on 6)

The device according to claim 6, wherein the electric cable is adapted in order to withstand a pressure of the insulating cable oil comprised between 1 and 20 bar.