Face seal with double spiral grooves
CA 2093151 C · Owner: Lai, Wei-Tang · Inventors: Lai, Wei-Tang
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A mechanical face seal for a high speed rotary fluid, pressure device comprising rotating and stationary seal rings disposed in a housing and having confronting radial seal faces normally biased into engagement with one another. Oppositely inclined sets of spiral grooves are formed in the seal face of one ring, one set functioning to pump fluid from the reservoir downstream between the seal faces, and the other set functioning to pump fluid between the faces upstream back toward the reservoir. Each downstream pumping groove preferably intersects only one upstream pumping groove. Fluid pressure between the faces forms a gap therebetween, and the reversely inclined groove construction …
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 1, 1993 and granted July 18, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 1, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 1, 2015.
- 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.