| Number | Date | Country | Kind |
|---|---|---|---|
| 4124657 | Jul 1991 | DEX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 2574830 | Howell | Nov 1951 | |
| 2687093 | Botts | Aug 1954 | |
| 3176617 | Brafford | Apr 1965 | |
| 3508518 | Flynn | Apr 1970 | |
| 4063508 | Whiting | Dec 1977 | |
| 4702167 | Reinelt et al. | Oct 1987 | |
| 4705655 | Maures et al. | Nov 1987 | |
| 4854238 | Vaice | Aug 1989 | |
| 5160804 | Wahner et al. | Nov 1992 |
| Number | Date | Country |
|---|---|---|
| 1074761 | Oct 1954 | FRX |
| Entry |
|---|
| PCT WO89/04453, Rahnenfuhrer et al, May 1989. |