| Number | Name | Date | Kind |
|---|---|---|---|
| D. 192920 | Beals | May 1962 | |
| D. 217251 | Kahn | Apr 1970 | |
| D. 261134 | Heritage | Oct 1981 | |
| D. 284532 | Vogt | Jul 1986 | |
| D. 301666 | Greutmann et al. | Jun 1989 | |
| D. 360324 | Vogt | Jul 1995 | |
| D. 401224 | Mollenkopf et al. | Nov 1998 | |
| 5826385 | Dykstra et al. | Oct 1998 |
| Entry |
|---|
| Allied Electronics 900 Engineering Manual & Purchasing Guide, c. 1990: p. 366—item Nos. UL2064 and UL2065. |