Grooved and perforated layer for use in papermakers' fabric
CA 2532735 C · Owner: Hawes, John · Inventors: Hawes, John
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A grooved perforated layer for use in a papermakers' fabric is provided. The grooves (8) serve to diffuse flow at the surface of the perforated (6) layer so as to reduce the pressure drop across the layer and thereby reduce the migration of fines. In this manner, the light/dark pattern associated with the fines is avoided and the quality of the resulting paper sheet is improved.
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 July 1, 2004 and granted October 2, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 1, 2024.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 1, 2026.
- 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.