Perforated window coverings
CA 2050314 A1 · Owner: Dunn, William F. · Inventors: Dunn, William F.; Dunn, William F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Light admitting window coverings are provided with apertures (36 38) which are formed in a covering such as a vertical blind louver (18). The louver is formed of opposed panel portions with a transparent film or sheet sandwiched therebetween to provide for sufficient light transmission and visibility through the louvers in the closed position but without permitting convective heat transmission through the window covering. The blind louvers may be formed with an insulating air space (64 66) between the opposed, louver panel portions and the transparent film or sheet. The blind louvers or single panel apertured blind louvers and the like may be formed with apertures at an acute angle …
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 January 12, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 12, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 12, 2012.
- 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.