Pump having a single or a plurality of helical blades
CA 2080591 C · Owner: Ishigaki, Eiichi · Inventors: Ishigaki, Eiichi; Oura, Kazumitsu; Honda, Takaharu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A vertical pump (1) having a single or plurality of helical blades (10, 11, 12) mounted on a forward end of a rotary drive shaft (2) of the pump. The pump is of non-blocked type in which the helical blade or blades (10 11, 12) are disposed with superior balance with respect to the rotary drive shaft (2), and is wide in flow passage between blade portions of the helical blades. The pump is particularly suitable for sewage treatment or the like.
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 28, 1991 and granted July 27, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 28, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 28, 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.