Releasable retaining means
CA 1095669 A · Owner: Dorgard Limited · Inventors: Welch, Anthony H. E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Means are provided for retaining fire doors in the open position against the action of the spring or other automatic. door closers, with remote control release which can be actuated if a fire is detected. In use one part thereof is mounted on the wall and has gripper means for engagement with another part which is mounted on the door. The wall-mounted part also includes release means spring-biased into a first position in which operation of the gripper means is inhibited and pneumatically operated means for holding the release means in a second position in which operation of the gripper means is not inhibited.
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 February 17, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 17, 1998.
- 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.