| Number | Name | Date | Kind |
|---|---|---|---|
| 905290 | Cummings et al. | Dec 1908 | |
| 1203656 | Shannon | Nov 1916 | |
| 1926843 | Fischer | Sep 1933 | |
| 1928480 | Carswell et al. | Sep 1933 | |
| 2073185 | Shafer | Mar 1937 | |
| 2126091 | Claybaugh | Aug 1938 | |
| 3727358 | Howell | Apr 1973 | |
| 4141666 | DeGraff | Feb 1979 | |
| 4318635 | Gurtner et al. | Mar 1982 | |
| 4650369 | Thomas et al. | Mar 1987 | |
| 5326191 | Wilson et al. | Jul 1994 |
| Number | Date | Country |
|---|---|---|
| 0023969 | Feb 1981 | EPX |
| 3415206 | Oct 1985 | DEX |
| Entry |
|---|
| Drawings, Kaiser Aluminum & Chemical Sales, Inc., Oakland, CA, Highway Products Division. |
| Brochure, "Aluminum Box Culvert", Contech Construction Products, Inc., Middletown, Ohio, .COPYRGT.1994. |