Web perforating apparatus
CA 1294536 C · Owner: Johnson, Roy A. · Inventors: Johnson, Roy A.; Ganz, Robert H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
As a conditioning step for wrapping a plurality of articles in a low density polyethylene shrink film perforations are formed in the shrink film for receiving machine elements utilized in performing the wrapping operation, the film being moved continuously between a pair of infeed rolls and a pair of outfeed rolls between which a rotatable mandrel is disposed and which includes perforating knives thereon for engaging the film while the film is moved continuously, the perforating knives being disposed on the opposite side of the web from a rotatable back up roll having cavities formed therein for receiving the ends of the perforating knives in such manner that the web is maintained under …
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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
- Granted January 21, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 21, 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.