| Number | Date | Country | Kind |
|---|---|---|---|
| 2002-082914 | Mar 2002 | JP |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4300297 | Betterley | Nov 1981 | A |
| 4399599 | Howe | Aug 1983 | A |
| 4570368 | Stover | Feb 1986 | A |
| 5225162 | Scoville | Jul 1993 | A |
| 5538291 | Gustafson | Jul 1996 | A |
| 5697177 | Ludlow et al. | Dec 1997 | A |
| 6401372 | Kovner | Jun 2002 | B1 |
| Number | Date | Country |
|---|---|---|
| 402102099 | Apr 1990 | JP |
| 9-61521 | Mar 1997 | JP |
| Entry |
|---|
| Japanese Patent Abstract in English—JP 9-61521. |