Method and apparatus for locating utility conveyances in an enclosed area
CA 2236092 C · Owner: Huffman, John Sinclair · Inventors: Eslambolchi, Hossein; Huffman, John Sinclair
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A selected one of a plurality of underground utility conveyances(14-14) may be located in an enclosure (10) by providing each conveyance with an electronic marker (18). Each marker is responsive to a first RF signal from an electronic marker locator (32) operated by a utility worker. Upon receipt of the first RF signal the, electronic marker associated with the conveyance of interest responds by broadcasting a second RF signal containing information indicative of the conveyance. The second RF signal is received and processed by the electronic locator marker to locate the conveyance and ascertain information related thereto.
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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 April 28, 1998 and granted June 12, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 28, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 28, 2020.
- 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.