Assignee
SHAFFER DONALD U
US·3 granted patents·215 citations·filing 1982–1986
Top patents by PatentIndex Score
3 records- 0186US4448255ARotary blowout preventerSHAFFER DONALD U·Filed 1982·Granted May 15, 1984·120 cites·14 claims
- 0278US4550895ARam construction for oil well blow out preventer apparatusSHAFFER DONALD U·Filed 1984·Granted Nov 5, 1985·60 cites·16 claims
- 0370US4688828ATubing joint for corrosion protectionSHAFFER DONALD U·Filed 1986·Granted Aug 25, 1987·35 cites·1 claims
Join the waitlist — get patent alerts
Get an alert when SHAFFER DONALD U files or is granted a new patent.
We store only your email — no account needed. See our privacy policy.
Counts cover granted patents and pending applications in the PatentIndex corpus. How scoring works →