| Number | Name | Date | Kind |
|---|---|---|---|
| 2051450 | Fischer | Sep 1960 | |
| 3539277 | Andrews et al. | Nov 1970 | |
| 3916911 | Sauder et al. | Nov 1975 | |
| 5141412 | Meinz | Aug 1992 |
| Number | Date | Country |
|---|---|---|
| 744943 | Jan 1933 | FRX |
| 975954 | Oct 1950 | FRX |
| 21304 | Oct 1905 | GBX |
| Entry |
|---|
| McQuiston et al., Heating Ventilating and Air Conditioning, 1982, pp. 574-575. |