| Date | Description | European Patent Bulletin date, issue number |
|---|---|---|
| 17.06.1992 | Withdrawal of application | published on 05.08.1992 [1992/32] |
| 06.02.1992 | First examination report | |
| 16.08.1990 | Request for examination filed | published on 03.10.1990 [1990/40] |
| 18.11.1989 | Publication in section I.1 EP Bulletin | published on 03.01.1990 [1990/01] |