| Number | Name | Date | Kind |
|---|---|---|---|
| RE22045 | Towart | Mar 1942 | |
| 2681707 | Mapes | Jun 1954 | |
| 3254807 | Boch et al. | Jun 1966 | |
| 4247048 | Hayes | Jan 1981 | |
| 4350298 | Tada | Sep 1982 | |
| 4619328 | Seyler et al. | Oct 1986 |
| Number | Date | Country |
|---|---|---|
| 1434924 | Oct 1968 | DEX |
| 2129730 | Dec 1971 | DEX |
| 2630519 | Jan 1978 | DEX |
| 612363 | Jul 1979 | CHX |
| 1466761 | Mar 1989 | SUX |
| 392433 | May 1933 | GBX |
| 439218 | Dec 1935 | GBX |
| 524474 | Aug 1940 | GBX |
| 731228 | Jun 1955 | GBX |
| 977280 | Dec 1964 | GBX |
| 1 363 941 | Aug 1974 | GBX |
| 1 588 302 | Apr 1981 | GBX |
| Entry |
|---|
| BRK Electronics product catalog CM759, p. 14, 1994. |
| BRK Brands product catalog CM760, pp. 6-7, 1995. |
| Pittway Corporation product catalog CM501, 3 pages, 1990. |