| Number | Name | Date | Kind |
|---|---|---|---|
| 706829 | Johnson | Aug 1902 | |
| 2464670 | Carlson | Mar 1949 | |
| 2551750 | Liskey | May 1951 | |
| 3557497 | Schafer et al. | Jan 1971 | |
| 5001866 | Powell et al. | Mar 1991 |
| Number | Date | Country |
|---|---|---|
| 2334648 | Jan 1975 | DEX |
| Entry |
|---|
| One (1) page from KNAPPCO Catalog dated Jan. 1987 illustrating a manhole cover. |