IP Library › Granted Patent US 4,802,150
Granted Patent Utility
US 4,802,150 · App. 06/295,457

Mud pressure control system with magnetic torque transfer

Inventors: Michael K. Russell, Anthony Russell
Patented Case View Patent ↗
Granted: Jan 31, 1989 Filed: Aug 24, 1981
Inventors
Michael K. Russell
Anthony Russell
Assignee (at issue)
NL Sperry-Sun, Inc.

This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.

Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 4,802,150
App. No.
06/295,457
Filed
1981-08-24
Granted
1989-01-31
Kind
A