Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4643618 | Soil reinforced cantilever wall | William K. Hilfiker | 1987-02-17 |
| 4505621 | Wire retaining wall apparatus and method for earthen formations | Harold K. Hilfiker | 1985-03-19 |