Container with twist-off tamper evident feature
CA 1285523 C · Owner: Wheeling Stamping Company · Inventors: Anthony, Eugene M.; Hans, Allan B.; Holoubek, George H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An integral seal member is formed across the outlet in the neck of a tamper evident, thermoplastic container by adding to the thermoplastic material such as polyethylene 3%, to 16%, and preferably about 8% by weight of an anhydrous, solid inorganic particulate additive such as an anhydrous siliceous material or calcium carbonate so that the material becomes brittle enough that the seal member tears cleanly from the neck within the confines of an undercut at the interface between the seal member and neck. Torque is applied to the seal member by providing in the top of a conventional screw cap which forms a resealing closure for the container once opened a recess with serrations which, when …
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 2, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 2, 2008.
- 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.