Manhole casting positioning apparatus and method
CA 1320071 C · Owner: Lui, John · Inventors: Armstrong, Ronald B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides an improvement in manhole casting positioning apparatus. In particular there is provided a casting positioning apparatus for positioning a, casting in relation to an upper end of a manhole which com-, prises an inner sleeve comprising an elongated planar piece of flexible material provided at either end thereof with a plurality of holes and adapted to form a cylinder having open upper and lower ends, the diameter of said cylinder being variable between a retracted position in which the lower end of the cylinder can freely enter the upper end of the manhole and an, expanded position in which the upper end of the cylinder can support the casting in a position …
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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 July 13, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 13, 2010.
- 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.