| Number | Name | Date | Kind |
|---|---|---|---|
| 2947406 | Hazelton, Jr. | Aug 1960 | |
| 3266626 | Simjian | Aug 1966 | |
| 3622151 | Range et al. | Nov 1971 | |
| 3750880 | Petrovsky et al. | Aug 1973 | |
| 3938435 | Suda et al. | Feb 1976 | |
| 4119194 | Freeman et al. | Oct 1978 | |
| 4625870 | Nao et al. | Dec 1986 | |
| 4863037 | Stevens et al. | Sep 1989 |
| Number | Date | Country |
|---|---|---|
| 1349353 | Dec 1963 | FRX |
| 0153408 | Dec 1961 | SUX |
| 1124099 | Aug 1968 | GBX |
| Entry |
|---|
| Xerox Disclosure Journal, vol. 7, No. 1, Jan./Feb., 1982--pp. 11-12, U.S. patent application Ser. No. 445,589, filed Nov. 30, 1982, now abandoned. |