| Date | Description | European Patent Bulletin date, issue number |
|---|---|---|
| 06.10.1990 | No opposition filed within time limit | published on 28.11.1990 [1990/48] |
| 28.10.1989 | (Expected) grant | published on 13.12.1989 [1989/50] |
| 25.02.1988 | First examination report | |
| 12.05.1987 | Publication of search report | published on 01.07.1987 [1987/27] |
| 23.01.1985 | Request for examination filed | published on 27.03.1985 [1985/13] |
| 15.10.1984 | Publication in section I.1 EP Bulletin | published on 12.12.1984 [1984/50] |