Fume hood with improved counterbalance system
CA 2182107 C · Owner: Fisher Hamilton Scientific Inc. · Inventors: Schlies, James J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A fume hood includes a housing with a work chamber an, access opening to the work chamber and a sash that one may move, between raised and lowered positions to open or close the access opening. It also includes a counterbalance system that maintains the sash at a desired position between two predetermined limits. An adjusting weight system reduces the weight provided by the counterbalance system or increases the weight of the sash to allow the sash to drop to a predetermined position after it has moved above that predetermined position.
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 25, 1996 and granted January 22, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 25, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 25, 2018.
- 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.