Automatic density controller apparatus and method
CA 2013161 C · Owner: Broaddus, James Everett · Inventors: Case, Leonard Ray; Pitts, Alan J.; Broaddus, James Everett
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An automatic mixture control apparatus includes a microcomputer-based data acquisition and control device which responds in real time to flowmeter and densimeter signals to control water inlet and bulk cement valves so that a cement slurry is produced at the desired rate and density. The data acquisition and control device is programmed to provide means for computing desired positions for the valves and for computing corrections for the positions. A related automatic mixture control method is also disclosed.
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed March 27, 1990 and granted February 20, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 27, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 27, 2012.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.