| Number | Name | Date | Kind |
|---|---|---|---|
| 4090247 | Martin | May 1978 | |
| 4094940 | Hold | Jun 1978 | |
| 4663710 | Waugh et al. | May 1987 | |
| 4674053 | Bannai et al. | Jun 1987 | |
| 4675826 | Gentry et al. | Jun 1987 | |
| 4688180 | Motomiya | Aug 1987 | |
| 4692216 | Polansky et al. | Sep 1987 |
| Number | Date | Country |
|---|---|---|
| 1911426 | Mar 1969 | DEX |
| 2609640 | Mar 1976 | DEX |
| 3024275 | Jun 1980 | DEX |
| 3335219 | Sep 1983 | DEX |
| Entry |
|---|
| Henry M. Morris (Control Engineering/Mar. 1987), Operator Convenience is Key as Process Controllers Evolve, pp. 65-70. |