Temperature-gradient type multistage condenser
CA 2214154 C · Owner: Shionogi & Co. Ltd. · Inventors: Okamoto, Joji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In the temperature-gradient type multistage condenser, a first cooling step is carried out at an outer cooling cylinder storing a freezing mixture. The outer cooling cylinder has an opening at the upper portion thereof and is constructed of double walls having a predetermined space between the walls, a second cooling step is carried out at a vertical pipe disposed substantially coaxially in the outer cooling cylinder and, a third cooling step is carried out at an inner cooling cylinder through which the vertical pipe passes. The cooling capacity is gradually increased as cooling proceeds from the first cooling step, and becomes substantially highest at the third cooling step wherein solvent …
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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 September 9, 1997 and granted May 9, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 9, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 9, 2019.
- 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.