| Number | Name | Date | Kind |
|---|---|---|---|
| 3961142 | Caffine | Jun 1976 | |
| 4468528 | Reece et al. | Aug 1984 | |
| 4517410 | Williams et al. | May 1985 | |
| 4577067 | Levy et al. | Mar 1986 | |
| 4834551 | Katz | May 1989 | |
| 4903291 | Tsurufuji et al. | Feb 1990 | |
| 4932050 | Davidson et al. | Jun 1990 | |
| 5592529 | Linsker | Jan 1997 | |
| 5606593 | Smith | Feb 1997 | |
| 5612997 | Vallelonga, Sr. et al. | Mar 1997 |
| Number | Date | Country |
|---|---|---|
| 0 027 188 | Apr 1981 | EP |
| 0 128 500 | Dec 1984 | EP |
| WO 9720121 | Jun 1997 | WO |
| Entry |
|---|
| European Patent Office, International Search Report, Mar. 18, 1999. |