| Number | Name | Date | Kind |
|---|---|---|---|
| D170434 | Walthall | Sep 1953 | |
| D193022 | Zurawski | Jun 1962 | |
| D227984 | Lang et al. | Jul 1973 | |
| 2737577 | McPhail | Mar 1956 |
| Number | Date | Country |
|---|---|---|
| 650,758 | Oct 1962 | CA |
| Entry |
|---|
| Plastic Process Co. Extrusion Catalog, 1953, p. 9, extrusion #1329; p. 16, extrusion #1391. |