| Number | Name | Date | Kind |
|---|---|---|---|
| 1406289 | Schaefer | Feb 1922 | |
| 1907625 | Vogt | May 1933 | |
| 1951418 | Jacobi | Mar 1934 | |
| 2032821 | Waits | Mar 1936 | |
| 2098189 | Kistner | Nov 1937 | |
| 4009599 | Patriquin | Mar 1977 | |
| 4099395 | Garza | Jul 1978 | |
| 4196605 | Garza | Apr 1980 | |
| 4809525 | Cox | Mar 1989 | |
| 5134764 | Taylor | Aug 1992 | |
| 5447049 | Shieh | Sep 1995 | |
| 5596894 | Lee | Jan 1997 | |
| 5765413 | Jung | Jun 1998 |
| Number | Date | Country |
|---|---|---|
| 1167217 | Apr 1964 | DEX |
| 1195200 | Jun 1965 | DEX |
| 404586 | Jan 1934 | GBX |
| Entry |
|---|
| Taiwan Laid-Open Utility patent No. 292627, published on Dec. 1, 1996. |