Boring device for a lining material applied onto the inner surface of a pipe line
CA 1292033 C · Owner: Zenbayashi, Katsuaki · Inventors: Morinaga, Akio; Zenbayashi, Katsuaki; Shimokawa, Shinji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A boring device for a lining material applied onto the inner surface of a pipe line which comprises a tension coil spring, a compression coil spring being connected to the tip of the tension coil spring and having a spring constant smaller than that of the tension coil spring, a head element in the form of a circular truncated cone being connected to the tip of the compression coil spring and comprised of an electric heat-generating means coated with a thermoplastic resin and a single or plural transmission wires being connected to the electric heat-generating means and being passed in loosened state through the tension coil spring and the compression coil spring, the transmission wires …
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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
- Granted November 12, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 12, 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.