Lock using air chambers
CA 2009660 C · Owner: Omachi, Toshikatsu · Inventors: Omachi, Toshikatsu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A lock using lock chambers and lock gates capable of reducing the water consumption in the operations of raising or lowering the boat passing through the lock from one level to another. The lock includes flexible air chambers capable of being inflated with air, located on bases of the lock chambers which are connected by a pipe equipped with a valve for controlling a flow of air between the air chambers.
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 February 9, 1990 and granted August 31, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 9, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 9, 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.