| Number | Date | Country | Kind |
|---|---|---|---|
| 43 28 995.9 | Aug 1993 | DEX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 1916908 | Stacey, Jr. et al. | Jul 1933 | |
| 1964845 | Dietze et al. | Jul 1934 | |
| 2112608 | Schmidt | Mar 1938 | |
| 2270825 | Parkinson et al. | Jan 1942 | |
| 3125286 | Sanders | Mar 1964 | |
| 3975995 | Shuler | Aug 1976 | |
| 4362223 | Meier | Dec 1982 | |
| 4608066 | Cadwell, Jr. | Aug 1986 | |
| 4747341 | Hedrick | May 1988 | |
| 5326317 | Ishizu et al. | Jul 1994 |
| Number | Date | Country |
|---|---|---|
| 3621452 | Jun 1986 | DEX |
| 150656 | Jun 1990 | JPX |
| 23616 | Jan 1991 | JPX |
| Entry |
|---|
| Fritz Mode; Ventilatoranlagen; 1972; pp. 22-25. |
| U. Ackermann; Schalldampfer fur Raumlufttechnische Anlagen; 1992; pp. 255-265. |