Sewer line multiple trap priming system and method
CA 2174581 C · Owner: Dowdican, Frank W. · Inventors: Dowdican, Frank W.; Perrott, Charles H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A sewer line multiple trap priming system comprises a house line and a plurality of branch lines all communicating with each other and supplied with water under pressure. A plurality of makeup priming water lines are connected one to each of the traps. In all but one of the branch lines pressure sensitive valves interconnect the branch lines and the makeup priming water lines. Upon a change in pressure in the branch lines by a predetermined increment these valves are operable, to inject a charge of priming water into the priming water lines and hence into the traps. In said one of the branch lanes from time to time valve means withdraws water from the communicating branch lines in amount …
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 19, 1996 and granted July 2, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 19, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 19, 2018.
- 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.