Fire safety door latch
CA 1312640 C · Owner: Best Lock Corporation · Inventors: Foshee, William R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A door latch bolt spring-biased to projected position and retracted by a lever or other unbalanced handle is provided with a blocker plate loosely mounted on the rear face of the bolt and held in nonblocking position by a fusible pin or other heat-sensitive element. In case of fire, when elevated temperature may weaken the biasing spring and allow the unbalanced handle to exert retracting force on the latch the, heat-sensitive element releases the blocker plate and allows it to drop to an operative position where it will move against a stop to block retraction of the bolt. The plate is movable in either direction on the bolt so as to be operative on either hand of door. The tailpiece of the …
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
- Granted January 12, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 12, 2010.
- 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.