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Inventor
ZWIEGEL JOHN M
US
2 patents
⚠️ This page may combine multiple inventors who share the name “ZWIEGEL JOHN M”. Patents are grouped by organization below to help distinguish them — per-person disambiguation is on the roadmap.
COOPER IND INC
1 patent
US5031696A
Jul 16, 1991
Casing hanger and seal
COOPER IND INC
31 citations
85
GRAY TOOL CO
1 patent
US4643390A
Feb 17, 1987
Fail-safe valve actuator
GRAY TOOL CO
9 citations
69