Laying structure for vacuum sewer pipe of vacuum sewage collecting system
CA 2037313 C · Owner: Ebara Corporation · Inventors: Ushitora, Akihiro; Yamaguchi, Kazuo; Hasegawa, Toshiyuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A laying structure for a vacuum sewer pipe of a vacuum sewage collecting system for collecting sewage discharged from homes and facilities into a collecting tank through a vacuum sewer pipe kept negative in pressure internally is disclosed. The vacuum sewer pipe includes a portion laid in a plain topography which comprises a downward pitch portion sloped toward downstream and a short, upward pitch portion connected to the downstream end of the downward pitch portion to return a depth of the vacuum sewer pipe to an original level, the downward pitch portion and the upward pitch portion are alternated at least once. The upward pitch portion starts from a spot deepened from the original …
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 August 22, 2000. 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.