| Number | Date | Country | Kind |
|---|---|---|---|
| 5-185204 | Jul 1993 | JPX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3620747 | Hamlin | Nov 1971 | |
| 4772542 | Haga | Sep 1988 | |
| 4948712 | Inoue et al. | Aug 1990 | |
| 4970140 | Heki et al. | Nov 1990 |
| Entry |
|---|
| Patent Abstracts of Japan, Vol. 14, No. 405; Aug. 31, 1990 JPA-2-157,751. |
| Patent Abstracts of Japan, vol. 17, No. 179; Apr. 7, 1993 JPA-4-333,839. |