| Number | Date | Country | Kind |
|---|---|---|---|
| 8912675[U] | Oct 1989 | DEX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3541552 | Carlson | Nov 1970 | |
| 3811265 | Cater | May 1974 | |
| 3881310 | Gerum et al. | May 1975 | |
| 4204398 | Lemelson | May 1980 | |
| 4602340 | Appleberg | Jul 1986 | |
| 4650344 | Allgaier et al. | Mar 1987 | |
| 4886981 | Lentini et al. | Dec 1989 |
| Number | Date | Country |
|---|---|---|
| 0062218 | Oct 1982 | EPX |
| 3541651 | Jun 1987 | DEX |
| Entry |
|---|
| Funkschau Feb. 1982, p. 112. |