| Number | Name | Date | Kind |
|---|---|---|---|
| 1681723 | Clas | Aug 1928 | A |
| 3313068 | Pinto | Apr 1967 | A |
| 3379488 | Lancor | Apr 1968 | A |
| 3589806 | Rak | Jun 1971 | A |
| 3663826 | Schumann et al. | May 1972 | A |
| 3684358 | Boudouris et al. | Aug 1972 | A |
| 4974252 | Osborne | Nov 1990 | A |
| 5026152 | Sharkey | Jun 1991 | A |
| 5218388 | Purdy | Jun 1993 | A |
| 5801754 | Ruybal et al. | Sep 1998 | A |
| 5862230 | Darby | Jan 1999 | A |
| 5872615 | Harris | Feb 1999 | A |
| 5924013 | Guido et al. | Jul 1999 | A |
| 5963247 | Banitt | Oct 1999 | A |
| 5988817 | Mizushima et al. | Nov 1999 | A |
| Entry |
|---|
| International Search Report, PCT/US99/27666. |