Splittable die
CA 2044424 C · Owner: British Gas Plc · Inventors: Maine, Leslie; Hicks, Kenneth
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A die 10 for reducing polyethylene pipe temporarily to enable it to be inserted in a pre-existing metal pipe is made of cast iron and has formations 20 by which the die is splittable into two portions. The formations receive cylindrical bars 14 which are squeezed together by a hydraulic squeeze off machine. Each formation is a Ushaped aperture with a saw cut 22 extending from the base of the U into the ligament beneath the formation. The saw cut acts as a stress raiser. In a modification only one formation is provided. The die is made of grey cast iron or some other brittle material.
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
- Filed June 12, 1991 and granted February 12, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 12, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 12, 2013.
- 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.