Gas actuated slide valve in a screw compressor
CA 2212942 C · Owner: Lakowske, Rodney L. · Inventors: Butterworth, Arthur L.; Andersen, Garry E.; Lakowske, Rodney L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The position of a slide valve in a screw compressor in a refrigeration system is controlled using a gaseous medium sourced from the higher pressure of two or more sources of such fluid. Preferred sources are refrigerant gas in a closed compression pocket in the working chamber of the compressor and refrigerant gas in the discharge passage downstream of the compressor's discharge port. The multiple sources of such gas are connected to a solenoid valve which, when open, permits gas to act on the piston which controls the position of the slide valve. Due to a check valve arrangement it is always , the one of the sources of gas which is at higher pressure that acts on the slide valve …
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 December 6, 1995 and granted February 6, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 6, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 6, 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.