| Number | Date | Country | Kind |
|---|---|---|---|
| 00 11473 | Sep 2000 | FR |
| Number | Name | Date | Kind |
|---|---|---|---|
| 1535529 | Hopkins | Apr 1925 | A |
| 1639699 | Hopkins | Aug 1927 | A |
| 3378168 | Hildebrandt | Apr 1968 | A |
| 3406872 | Fiquet et al. | Oct 1968 | A |
| 4340154 | VanManen | Jul 1982 | A |
| 4687663 | Schaeffer | Aug 1987 | A |
| 5076470 | Hatakeyama et al. | Dec 1991 | A |
| 5419459 | O'Meara | May 1995 | A |
| 6003728 | Elliott | Dec 1999 | A |
| Number | Date | Country |
|---|---|---|
| 23 50 773 | Apr 1975 | DE |
| 0 564 208 | Oct 1993 | EP |
| Entry |
|---|
| English language Derwent Abstract of DE 23 50 773, Apr. 24, 1975. |