| Number | Date | Country | Kind |
|---|---|---|---|
| 52/130405 | Oct 1977 | JPX | |
| 52/131003 | Nov 1977 | JPX | |
| 53/17432 | Feb 1978 | JPX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3254596 | Shovp et al. | Jun 1966 | |
| 3571581 | Kaus | Mar 1971 | |
| 3650205 | Hybrow et al. | Mar 1972 | |
| 3778766 | Rapp | Dec 1973 | |
| 3815495 | Straudbein | Jun 1974 | |
| 4085670 | Poole | Apr 1978 |
| Number | Date | Country |
|---|---|---|
| 693554 | Jul 1953 | GBX |
| 693730 | Jul 1953 | GBX |
| 1225121 | Mar 1971 | GBX |
| 1242843 | Aug 1971 | GBX |
| Entry |
|---|
| Lavin et al. IBM Tech. Discl. Bulletin, vol. 10, No. 12, May, 1968, pp. 1872-1873. _ |