| Number | Name | Date | Kind |
|---|---|---|---|
| 3814148 | Wostl | Jun 1974 | |
| 4186381 | Fleischer et al. | Jan 1980 | |
| 4263945 | Van Ness | Apr 1981 | |
| 4345146 | Story et al. | Aug 1982 | |
| 4469149 | Walkey et al. | Sep 1984 | |
| 4901748 | Shotmeyer | Feb 1990 | |
| 5156198 | Hall | Oct 1992 | |
| 5310999 | Claus et al. | May 1994 | |
| 5343906 | Tibbals, III | Sep 1994 | |
| 5579233 | Burns | Nov 1996 | |
| 5596501 | Comer et al. | Jan 1997 |
| Number | Date | Country |
|---|---|---|
| 0 476 858 A1 | Mar 1992 | EPX |
| 0 618 557 A1 | Oct 1994 | EPX |
| 2 600 318 | Dec 1987 | FRX |
| 2 224 418 | May 1990 | GBX |
| WO 9012366 | Oct 1990 | WOX |
| Entry |
|---|
| International Search Report mailed Jul. 18, 1997. |