Door exit-delaying means
CA 2036632 C · Owner: Muller, Peter H. · Inventors: Muller, Peter H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a first embodiment, the invention has a casing set in the frame of a door in confronting relationship to the latchbolt-confining housing of the door. A bolt, translatable in the casing, is extended by a, solenoid, and enters the housing to prevent opening of the door. A latchbolt position sensor, in the form of a dual-ended limb, monitors the position of the latchbolt. Upon withdrawal of the latchbolt from, latching closure of the door, the limb actuates a switch to operate a time delay circuit component. When the specified time delay set by the component has run its course, it cuts power to the solenoid. Compression springs withdraw the bolt from the latchbolt-confining housing, to …
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 February 19, 1991 and granted December 16, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 19, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 19, 2013.
- 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.