| Number | Date | Country | Kind |
|---|---|---|---|
| 8702151 | Jan 1987 | GBX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 1899316 | Dehuff | Feb 1933 | |
| 4387002 | Knecht | Jun 1983 | |
| 4605569 | Shimada et al. | Aug 1986 |
| Number | Date | Country |
|---|---|---|
| 2431842 | Feb 1980 | FRX |
| Entry |
|---|
| European patent application No. 0 091 321, 10/12/1983. |
| European patent application No. 0 043 645, 1/13/82. |