Inventor
David N. Shirley-Fisher
Inventor
Cheltenham, GB
Overview
Patents· 2 as inventor
Public. Assignee & technology derived from the patent record. Each patent links to its LexDana page.
E21Bprimary
E21BEarth or rock drilling50%
B23CMilling25%
Y10TTechnical subjects covered by former us classification25%
Career & activity timeline
Assembled from patent assignee/location history and declaration credentials.
1987–1990Patents assigned to NL PETROLEUM PROD (2)· patent assignee history
1987–1990Based in Cheltenham, GB· patent location history
Inventor activity
Assignee and location history derived from the patent record.
Assignees
| Assignee | Patents | Span |
|---|---|---|
| NL PETROLEUM PROD | 2 | 1987–1990 |
Locations
| Location | Patents | Span |
|---|---|---|
| Cheltenham, GB | 2 | 1987–1990 |