Shut-off seal for a rotatable shaft
CA 2073614 C · Owner: Robbins & Myers, Inc. · Inventors: Larkins, David J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A shut-off seal for a rotatable shaft penetrating a fluid-holding tank through an opening below the fluid surface. The shut-off seal has a collar secured to the shaft inside the tank and a positionable annular shut-off ring which may be moved into engagement with the collar. The invention enables leakage-free shutdown for servicing an associated rotary seal without moving the rotary seal axially along the shaft.
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 10, 1992 and granted May 6, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 10, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 10, 2014.
- 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.