Filter
CA 2296422 A1 · Owner: De Boer, Anthony · Inventors: De Boer, Anthony
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A filter structure, typically for in ground use on perforated pipes, in which a tubular knit fabric is used thus providing the elasticity, inherent in a knit construction but the yarns of the fabric are napped or suaded, cutting filaments from them. The filaments extend across the stitch opening, reducing the micron size rating of the filter without the need to use more and costly yarn. Preferably the filaments are cut from additional laid-in yarns while leaving the base or ground structure of the fabric intact and hence unweakened. The napping or suading can be on the inside or outside of the filter fabric. The filter can be used for gases as, well as liquids and can be on flat sheets as …
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 January 19, 2000. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 19, 2020.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 19, 2022.
- 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.