Seal/bearing assembly
CA 2193482 C · Owner: A. W. Chesterton Co. · Inventors: Ramsay, Thomas W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
For fitment into the stuffing box, of a centrifugal pump. A spiralgroove is cut on the outer surface of, the rotor of a pair of tapered bearing surfaces. The groove is 0.02 mm, deep 2 mm wide, and its circumfer-, ential length is 50 cm. Barrier-liquid is fed to an entry-mouth of the spiralgroove, and groove generates a pres-, sure in the stuffing box high enough to overcome process pressure. The, barrier-liquid may be water. The interface between the bearing surfaces is sealed from the process-fluid and from the outside.
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, 1995 and granted August 20, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 19, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 19, 2017.
- 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.