| (19) |
 |
|
(11) |
EP 0 178 796 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
27.05.1987 Bulletin 1987/22 |
| (43) |
Date of publication A2: |
|
23.04.1986 Bulletin 1986/17 |
| (22) |
Date of filing: 18.09.1985 |
|
|
| (84) |
Designated Contracting States: |
|
DE NL |
| (30) |
Priority: |
15.10.1984 GB 8426009
|
| (71) |
Applicant: VACUUM INTERRUPTERS LIMITED |
|
() |
|
| (72) |
Inventors: |
|
- Atkinson, Denzil Malcolm
()
- Melkin, Peter
()
|
|
| |
|
| (54) |
Manufacture of vacuum interrupter contacts |
(57) A method of manufacturing vacuum interrupter contacts by mixing powdered copper with
powdered chromium and less than 0.25% powdered bismuth, cold pressing the mixture
up to more than 90% of theoretical maximum density, sintering under vacuum, and then
cold coining the contact up to more than 97% of theoretical maximum density. The bismuth
may in some cases be replaced by lead, tellurium, thallium, antimony, tungsten or
a mixture thereof.