| Number | Name | Date | Kind |
|---|---|---|---|
| 3540711 | Shelton et al. | Nov 1970 | |
| 4090622 | Smith et al. | May 1978 | |
| 4648836 | Thom | Mar 1987 | |
| 5303904 | Kemp | Apr 1994 | |
| 5382002 | Evans et al. | Jan 1995 | |
| 5407498 | Kemp | Apr 1995 |
| Entry |
|---|
| Brochure of Vacuum Industries, Inc. on "ROTAVAC" Furnaces, published, Dec. 1989 in Nashua, NH, 4 page folder and 6 page insert. |