Patent Assignment
Reel/Frame 004112/0800
Assignment of Assignors Interest.
Recorded: 1983-03-31
Pages: 1
Assignor
KROL, DAVID A.
Executed: 1983-03-16
Assignee
GULF RESEARCH & DEVELOPMENT COMPANY, A CORP. OF DEL.
PITTSBURGH, PENNSYLVANIA
Covered Property
(1)
Method of Freeing Stuck Drill String Using Spotting Fluid
Patent:
4,491,181 →
Application:
06/480,877 →
Related Assignments
(1)
Other recorded transfers of the patent in this record — the chain of ownership.