Automatic cement mixing and density simulator and control system and equipment for oil well cementing
Patent 5571281 Issued on November 5, 1996. Estimated Expiration Date: February 9, 2016. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
366/2, Methods366/163.1, By suction366/178.1, Concentric366/178.3Inner feeder passes through wall of outer feeder and extends along common axis at the wall