Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4543159 | Reinforced cement sheet product containing no asbestos for fabricating on Hatschek machine | Robert M. Johnson | 1985-09-24 |
| 4428775 | Reinforced cement sheet product containing no asbestos for fabricating on hatschek machine | Robert M. Johnson | 1984-01-31 |
| 4377415 | Reinforced cement sheet product containing wollastonite for reduced shrinkage | Robert M. Johnson | 1983-03-22 |
| 4363666 | Reinforced cement sheet product containing fibers other than asbestos, clay and thickener | Robert M. Johnson | 1982-12-14 |