Fume hood exhaust terminal having an electrically driven linear actuator
CA 2214819 C · Owner: Landis & Staefa, Inc. · Inventors: Jacob, Steven D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A fume hood exhaust terminal for controlling gas flow in an exhaust duct has an electrically driven linear actuator for angularly positioning a damper in the terminal. Drive circuitry employed in the preferred embodiment prevents the possibility of shorting out the actuator motor in the event of an input signal condition which would attempt to operate the motor in two directions simultaneously. The circuit also includes a power failure detection circuit which includes the capability of storing sufficient power to place the damper in a preferred position until power is restored to the exhaust terminal.
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 September 5, 1997 and granted June 10, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 5, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 5, 2019.
- 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.