| Number | Name | Date | Kind |
|---|---|---|---|
| 2579835 | Lather | Dec 1951 | |
| 2693742 | Hartman | Nov 1954 | |
| 2942765 | Baumgartner | Jun 1960 | |
| 3658220 | Norton | Apr 1972 | |
| 4568322 | Piggott | Feb 1986 | |
| 4586916 | Williams et al. | May 1986 |
| Entry |
|---|
| "Baum 500 Series High Speed Folder" brochure, Baum USA, undated, .COPYRGT.1988. |