Thermal type flowmeter
CA 2044655 C · Owner: Katougi, Hiroyuki · Inventors: Katougi, Hiroyuki; Matubara, Naoki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A heat-conductive stream pipe has an upstream side and a downstream side temperature-sensing element having resistance wires wound round the pipe at a certain distance there-between to assure that there will be no thermal affection with each other. A control means controls a bridge circuit including an earthen point at one end and a connecting point at the other end of each of the temperature-sensing elements so as to keep the temperature difference between the upstream side and the downstream side temperature-sensing elements at a constant level. An auxiliary heater adjustable in its temperature is placed on the stream pipe at the downstream side near the downstream side …
Read the whole patent
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 June 14, 1991 and granted December 11, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 14, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 14, 2013.
- 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.