| Number | Name | Date | Kind |
|---|---|---|---|
| 2698173 | Rydell | Dec 1954 | |
| 2767979 | Hummert | Oct 1956 | |
| 4521993 | Tacheny et al. | Jun 1985 | |
| 4553656 | Lense | Nov 1985 | |
| 5097629 | Guhl et al. | Mar 1992 | |
| 5179803 | Lense | Jan 1993 | |
| 5205074 | Guhl et al. | Apr 1993 |
| Number | Date | Country |
|---|---|---|
| 1351096 | Dec 1963 | FRX |
| 186760 | Jun 1907 | DEX |
| 824752 | Nov 1951 | DEX |
| 9003179 | Jul 1990 | DEX |
| 324587 | Nov 1957 | CHX |
| 1132744 | Nov 1968 | GBX |
| Entry |
|---|
| English translation of German Patent 186,670. |
| English translation of German Patent 824,752. |
| English translation of German Utility Model No. 90 03 179.2. |
| English translation of Swiss Patent 324,587. |