| Number | Name | Date | Kind |
|---|---|---|---|
| 193906 | Wood, Jr. | Aug 1877 | A |
| 3279114 | Lewis et al. | Oct 1966 | A |
| 3332162 | Martwick et al. | Jul 1967 | A |
| 3507067 | Into | Apr 1970 | A |
| 3557482 | Hoover | Jan 1971 | A |
| 3641691 | Ellis et al. | Feb 1972 | A |
| 3967402 | Cooksey | Jul 1976 | A |
| 3967403 | Reynolds | Jul 1976 | A |
| 4689911 | White | Sep 1987 | A |
| 5052144 | Ostor | Oct 1991 | A |
| Number | Date | Country |
|---|---|---|
| 1 944 650 | Mar 1971 | DE |
| 0 085 193 | Dec 1982 | EP |
| 2 218 191 | Nov 1989 | GB |
| Entry |
|---|
| English language abstract of EP 0 085 193 A1. |
| International Search Report dated May 31, 2000. |