Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4320924 | Reciprocated concrete surfacer member with shielded spring return | Edward R. Langfield, David L. Hird | 1982-03-23 |
| 4252375 | Wear or thrust plates for hydraulic rock splitting apparatus | Edward R. Langfield | 1981-02-24 |
| 4215901 | Hydraulically actuated tool for mechanically splitting rock-like material | Edward R. Langfield, David L. Hird | 1980-08-05 |