Assignee
NAT OILWELL
US·21 granted patents·1,058 citations·filing 1981–1993
Top patents by PatentIndex Score
21 records- 0197US4951707ASeal for a pump valveNAT OILWELL·Filed 1989·Granted Aug 28, 1990·119 cites·19 claims
- 0296US4843945AApparatus for making and breaking threaded well pipe connectionsNAT OILWELL·Filed 1987·Granted Jul 4, 1989·181 cites·16 claims
- 0389US4922957AValve with replaceable seal elementNAT OILWELL·Filed 1989·Granted May 8, 1990·60 cites·19 claims
- 0486US4809733AFail-safe gate valve with separated actuatorsNAT OILWELL·Filed 1987·Granted Mar 7, 1989·88 cites·18 claims
- 0581US5038871AApparatus for supporting a direct drive drilling unit in a position offset from the centerline of a wellNAT OILWELL·Filed 1990·Granted Aug 13, 1991·79 cites·29 claims
- 0680US4781359ASub assembly for a swivelNAT OILWELL·Filed 1987·Granted Nov 1, 1988·99 cites·9 claims
- 0778US4981180APositive lock of a drive assemblyNAT OILWELL·Filed 1989·Granted Jan 1, 1991·71 cites·12 claims
- 0876US5149143AConnector assembly with detachable sleeveNAT OILWELL·Filed 1991·Granted Sep 22, 1992·71 cites·14 claims
- 0971US4787524AOverload protection system for a craneNAT OILWELL·Filed 1985·Granted Nov 29, 1988·33 cites·15 claims
- 1069US4732061APower tongs and clamping units thereforNAT OILWELL·Filed 1987·Granted Mar 22, 1988·41 cites·14 claims
- 1163US5346178APressure equalized flow control valveNAT OILWELL·Filed 1993·Granted Sep 13, 1994·24 cites·11 claims
- 1262US5051007ALubrication of a centrifugal pump bearingNAT OILWELL·Filed 1989·Granted Sep 24, 1991·27 cites·13 claims
- 1361US4809792ASupport system for a top driven drilling unitNAT OILWELL·Filed 1988·Granted Mar 7, 1989·30 cites·20 claims
- 1460US4746246ARemotely actuated cutting assembly for broken underwater guidelinesNAT OILWELL·Filed 1981·Granted May 24, 1988·26 cites·15 claims
- 1557US5127478ACasing suspension systemNAT OILWELL·Filed 1991·Granted Jul 7, 1992·29 cites·22 claims
- 1654US4813498AActive counterbalance for a power swivel during well drillingNAT OILWELL·Filed 1988·Granted Mar 21, 1989·25 cites·23 claims
- 1746US4782662ABoom crane centeringNAT OILWELL·Filed 1987·Granted Nov 8, 1988·11 cites·5 claims
- 1842US4797029ARemotely installing a tubular stringNAT OILWELL·Filed 1986·Granted Jan 10, 1989·14 cites·5 claims
- 1935US5246075AGuide post latching mechanismNAT OILWELL·Filed 1992·Granted Sep 21, 1993·13 cites·13 claims
- 2035US5062667AConnection sealNAT OILWELL·Filed 1990·Granted Nov 5, 1991·11 cites·16 claims
- 2130US4877093ASpring actuated power swivel support rollersNAT OILWELL·Filed 1988·Granted Oct 31, 1989·6 cites·11 claims
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