Reusable resilient gasket and method for using same
CA 2178494 C · Owner: Minor, Raymond B. · Inventors: Dauber, Edwin G.; Mcgregor, Gordon L.; Minor, Raymond B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved gasket particularly suitable for use in sensitive environments is disclosed. The preferred gasket of the present invention comprises at least one layer of a composite material of porous polytetrafluoroethylene (PTFE) polymer and resilient expandable microspheres. The composite material provides a number of significant advantages over existing PTFE and similar clean gaskets, including better seal under less compressive pressure, sufficient resilience to permit reuse and, retained porosity-allowing pressure equalization in the equipment to occur through the gasket itself.
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 May 4, 1994 and granted February 29, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 4, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 4, 2016.
- 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.