Issued Patents All Time
Showing 1–8 of 8 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| D477210 | Joist reinforcing bracket | Robert M. Callahan | 2003-07-15 |
| D472791 | Joist reinforcing bracket | Robert M. Callahan | 2003-04-08 |
| D472792 | Joist reinforcing bracket | Robert M. Callahan | 2003-04-08 |
| D472793 | Joist reinforcing bracket | Robert M. Callahan | 2003-04-08 |
| 5921053 | Internally reinforced girder with pierceable nonmetal components | Robert M. Callahan | 1999-07-13 |
| 5832691 | Composite beam | Robert M. Callahan | 1998-11-10 |
| 5625997 | Composite beam | Robert M. Callahan | 1997-05-06 |
| 5519977 | Joist reinforcing bracket | Robert M. Callahan | 1996-05-28 |