Vacuum countergravity casting apparatus and method
CA 2000868 A1 · Owner: General Motors Corporation · Inventors: Chandley, George D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure, A vacuum countergravity casting apparatus includes a vacuum chamber and a gas permeable mold sealingly mounted in the mouth of the chamber and comprising a gas permeable upper mold member and a lower mold member held in sealing engagement at a mold parting plane without glue. To this end the, upper mold member includes an exterior mold surface confronted by the vacuum chamber and a plurality of vacuum passages extending between the exterior mold surface and a bottom parting surface thereof to expose an effective area of the lower mold member to subambient pressure in the chamber sufficient to urge the lower mold member into sealing engagement with the upper mold …
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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 October 17, 1989. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 17, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 17, 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.