Injection molding apparatus and method
CA 2002007 C · Owner: Baxi, Indra R. · Inventors: Erikson, Erik E.; Baxi, Indra R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method and apparatus for making a plastic injection molded part with a smooth surface or skin and a hollow core wherein thermoplastic material is injected as a molten stream into the mold cavity through a sprue bushing fixed in the mold. Simultaneously an unmeasured quantity of inert gas is introduced through an adapter into the molten stream at the sprue bushing substantially coaxially with the melt stream and at a pressure sufficient to penetrate the thermoplastic material to form a gas cavity in the molten material in the mold. For retrofitting an existing mold, an adapter can be added to the exisiting sprue bushing. During plastic injection and cooling in the mold the gas is …
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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 1, 1989 and granted February 24, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 1, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 1, 2011.
- 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.