| Number | Date | Country | Kind |
|---|---|---|---|
| 53/100775 | Aug 1978 | JPX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 2151024 | Gilbert | Mar 1939 | |
| 3814659 | Nadeau | Jun 1974 | |
| 3903346 | De Leon et al. | Sep 1975 | |
| 3940517 | De Leon | Feb 1976 | |
| 4067833 | Austin et al. | Jan 1978 | |
| 4073997 | Richards et al. | Feb 1978 | |
| 4118533 | Hipchen et al. | Oct 1978 | |
| 4121958 | Koonts | Oct 1978 | |
| 4131518 | Fromson | Dec 1978 | |
| 4189541 | Ohashi et al. | Feb 1980 | |
| 4205110 | Jean | May 1980 | |
| 4212917 | Skowronski | Jul 1980 |
| Number | Date | Country |
|---|---|---|
| 2253890 | Jul 1975 | FRX |
| 900876 | Jul 1962 | GBX |
| Entry |
|---|
| U.K. Patent Application GB No. 2,007,590 A, Published May 23, 1979. |