| Number | Name | Date | Kind |
|---|---|---|---|
| 3968632 | Gaeddert et al. | Jul 1976 | |
| 3974632 | Van der Lely | Aug 1976 | |
| 4072096 | Phillips | Feb 1978 | |
| 4135352 | Swenson et al. | Jan 1979 | |
| 4206587 | Freimuth et al. | Jun 1980 | |
| 4208862 | Waldrop et al. | Jun 1980 | |
| 4218866 | Parrish | Aug 1980 | |
| 4238919 | Parrish | Dec 1980 | |
| 4242857 | Parrish | Jan 1981 | |
| 4375187 | Kluver et al. | Mar 1983 | |
| 4393764 | Viaud | Jul 1983 |
| Entry |
|---|
| U.S. Patent Application, Serial 294,651, filed Aug. 20, 1981, Jean Viaud. |