Improved fluid displacing blade
CA 2286705 C · Owner: Leung, Chi Keung · Inventors: Leung, Chi Keung
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A propeller (11) having five blades (13) supported from a hub (14) is exemplified. The propeller (11) is shown with the faces (15) of those blades (13) facing the viewer (out of the page) and has apertures (19) extending , through each blade (13) from the face (15) to the back of each blade (13) and , spread relatively evenly across the extent of each blade. The axial extent of the apertures (19) is substantially aligned with the direction of movement of the blades (13) relative to the axis of the propeller (11). The apertures (19) are normal both to the radial extent of the propeller (11) and the axial extent of the propeller. Each aperture (19) includes a bevelled edge in the form …
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 April 8, 1998 and granted November 25, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 8, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 8, 2020.
- 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.