Filter cloth, filter method and filtering device for liquid filtration
CA 2258167 C · Owner: Grabbe, Ulrich · Inventors: Seyfried, Carl Franz; Grabbe, Ulrich
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A filter cloth for liquid filtration is made as a long-pile fabric the pile , threads 21 of which lie on, the flow side and are displaced against the supporting fabric during the filtration and form a deep, filter, which at the time of back washing they are straightened by the back washing and release the, dirt particles. The back washing is performed preferably by means of a suction bar 13, which at, the same time acts mechanically on the pile threads in order to promote an , abrupt straightening of the pile threads at the time of back washing and the flattening of the pile threads after the back, washing.
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 June 19, 1997 and granted September 17, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 19, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 19, 2019.
- 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.