Maintaining perforation phasing
CA 2109910 C · Owner: Hatchell, Peter J. · Inventors: Hatchell, Peter J.; Lambrecht, Emiel; Anderson, Danford C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In an apparatus for making plastic bags or the like from a continuous film of material comprising a sealing drum having at least one seal bar for imparting transverse seals to the film at regularly spaced intervals and a perforator having a rotatable perforator blade for imparting transverse perforations to the film at regularly spaced intervals the film comprising printmarks appearing thereon at regularly spaced intervals an apparatus and, method are disclosed for tracking the positions of each print mark and each perforation and comparing the difference between these positions to a desired difference and thereafter adjusting the angular position of the perforator blade until the …
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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 November 24, 1993 and granted March 18, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 24, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 24, 2015.
- 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.