| Number | Date | Country | Kind |
|---|---|---|---|
| 4101738 | Jan 1991 | DEX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 1508572 | Ord | Sep 1924 | |
| 2482659 | Davis et al. | Sep 1949 | |
| 2521046 | Darwin | Sep 1950 | |
| 2577272 | Sager | Dec 1951 | |
| 2601501 | Cain | Jun 1952 | |
| 3374701 | Wallenberg | Mar 1968 | |
| 3412496 | Hendricks et al. | Nov 1968 | |
| 4831758 | Williams et al. | May 1989 | |
| 5031346 | Herring et al. | Jul 1991 | |
| 5077923 | Rockola et al. | Jan 1992 | |
| 5136562 | Staar | Aug 1992 |
| Number | Date | Country |
|---|---|---|
| 0138005 | Apr 1985 | EPX |
| 274379 | May 1914 | DEX |
| 1017378 | Oct 1957 | DEX |
| Entry |
|---|
| Abstract and drawing for 60-256969, Japan, date May 20, 1986. |
| Abstract and drawing for 62-256-261, Japan, date Apr. 26, 1988. |