| (19) |
 |
|
(11) |
EP 0 573 313 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
09.02.1994 Bulletin 1994/06 |
| (43) |
Date of publication A2: |
|
08.12.1993 Bulletin 1993/49 |
| (22) |
Date of filing: 07.06.1993 |
|
| (51) |
International Patent Classification (IPC)5: H01B 13/00 |
|
| (84) |
Designated Contracting States: |
|
DE ES FR GB IT |
| (30) |
Priority: |
05.06.1992 GB 9211944
|
| (71) |
Applicant: BICC Public Limited Company |
|
London W1X 5FH (GB) |
|
| (72) |
Inventor: |
|
- Mills, Eric
Prescot,
Lancashire (GB)
|
| (74) |
Representative: Dlugosz, Anthony Charles et al |
|
BICC Group Patents & Licensing Department
Quantum House
Maylands Avenue
Hemel Hempstead
Hertfordshire HP2 4SJ
Hemel Hempstead
Hertfordshire HP2 4SJ (GB) |
|
| |
|
| (54) |
Mineral insulated electric cable manufacture |
(57) A method of manufacturing mineral insulated electric cable comprises locating one
or more conductor rods in a metal tube, introducing mineral insulating powder into
the tube and then drawing the filled tube through one or more reducing dies to reduce
the diameter of the tube to the required size, wherein the die, or at least one of
the dies is continuously subjected to ultrasonic radial vibrations.
The method has the advantage that greater reductions in diameter of the tube can be
achieved between annealing steps due to reduction of damage to the conductor rods
and the metal tube by the mineral insulating powder.