| Number | Date | Country | Kind |
|---|---|---|---|
| 8412876 | May 1984 | GBX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 1004194 | Platt | Sep 1911 | |
| 1060284 | Platt | Apr 1913 | |
| 2634740 | Duke | Apr 1953 | |
| 2666260 | Schneider et al. | Jan 1954 | |
| 3127684 | Ernst | Apr 1964 | |
| 4057903 | Cantera | Nov 1977 |
| Number | Date | Country |
|---|---|---|
| 2120718 | Jul 1983 | GBX |
| Entry |
|---|
| European Patent Application, 0033992, 19/08/81, Voskanys. |
| European Patent Application 075,089, 29/06/83, Hummel. |