| Date | Description | European Patent Bulletin date, issue number |
|---|---|---|
| 25.06.1992 | No opposition filed within time limit | published on 12.08.1992 [1992/33] |
| 05.07.1991 | (Expected) grant | published on 21.08.1991 [1991/34] |
| 10.10.1990 | First examination report | |
| 03.08.1989 | Request for examination filed | published on 20.09.1989 [1989/38] |
| 21.12.1988 | Publication of search report | published on 08.02.1989 [1989/06] |
| 10.10.1987 | Publication in section I.1 EP Bulletin | published on 25.11.1987 [1987/48] |