Door closer
CA 1320512 C · Owner: Cornwell, Christopher M. · Inventors: Kopec, John; Cornwell, Christopher M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A door closer of the kind which acts between a door hinge stile and a hinge jamb has a body for mounting usually in the stile, and from the body a spring-biased tension member extends for anchoring to the jamb. A hydraulic cylinder piston damper is interposed between the tension member and its biasing spring, the damper incorporating no unidirectional valve means and instead its piston being undersized relative to the cylinder by an amount predetermined by the viscosity of hydraulic fluid in the damper so as to allow fluid to flow restrictedly around the piston when the tension member is moved in door-closing and door-opening directions.
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 July 20, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 20, 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.