| Number | Date | Country | Kind |
|---|---|---|---|
| 97200556 | Feb 1997 | EPX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3696734 | Beasley et al. | Oct 1972 | |
| 3779772 | Forkner | Dec 1973 | |
| 4153733 | Pierce | May 1979 | |
| 4927656 | Ito | May 1990 | |
| 4937084 | Julian et al. | Jun 1990 |
| Number | Date | Country |
|---|---|---|
| 393361 | Oct 1990 | EPX |
| 561 513 | Sep 1993 | EPX |
| 582922 | Feb 1994 | EPX |
| 9423583 | Oct 1994 | WOX |
| Entry |
|---|
| International Search Report in the application of PCT/EP 97/04572 dated Dec. 29, 1997. |