Fire-resistant door
CA 1309897 C · Owner: Lehnert, Charles W. · Inventors: Fowler, George F.; Lehnert, Charles W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A fire-resistant door comprises a core panel of mineral material, such as gypsum wallboard. A fiber mat preferably comprising glass fibers, is at least partially embedded in each face of said core panel. An edge banding assembly disposed around the periphery of the core panel is centrally grooved to receive the panel edges. Facing sheets are affixed to the opposite sides of the edge banding assembly in spaced parallel relation to the core panel, and a spacer material at least partially fills the spaces between the facing sheets and the core panel.
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 November 10, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 10, 2009.
- 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.