| Number | Name | Date | Kind |
|---|---|---|---|
| 1049822 | Prat | Jan 1954 | |
| 3391976 | Lindblom | Jul 1968 | |
| 3584939 | Olson et al. | Jun 1971 | |
| 4405214 | Bolle | Sep 1983 | |
| 4670915 | Evans | Jun 1987 |
| Number | Date | Country |
|---|---|---|
| 2419526 | Nov 1979 | FRX |
| 2472764 | Jul 1981 | FRX |
| 144718 | Nov 1980 | DDX |
| 2117919 | Oct 1983 | GBX |
| Entry |
|---|
| C. Grendol et al., U.S. Ser. No. 749,579 filed Jun. 27, 1985. |