Apparatus and methods for twin sheet thermoforming
CA 2318933 A1 · Owner: Hill, Christopher Jason · Inventors: Vaughan, Stewart; Hill, Christopher Jason
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of twin sheet thermoforming is provided in which the seam (1) between sheets (7, 8) is trimmed from the finished part by a shearing action between cooperating edges of the mould halves (3 4). In the preferred from of the , invention one mould half (4) is provided with a moveable pinch-off region (13) which retracts under pressure from the other mould half (3) to leave an edge of the mould half (4) adjacent the mould cavity which cooperates with an edge of the mould cavity of the other mould half (3) to provide the shearing action. The moveable pinch-off region may be a pinch-off member (13) supported in an annular channel (14) by a pre-compressed spring (15). The invention …
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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 January 21, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 21, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 21, 2021.
- 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.