Levelling rod, level determining apparatus for said rod, and level determining method
CA 2563983 C · Owner: Zheng, Zheng Dong · Inventors: Ng, Chin Keong; Zheng, Zheng Dong; Zhou, Keliang
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The levelling rod (1) for a level determining apparatus (2) has position indications therealong along expressed by barcode symbols (11 12). At least , some of said barcode symbols are colour barcode symbols the colour serving to , encode said position indications. The barcode symbols can be organised in first and second blocks (12, 11) of barcode symbols each providing a position , indication wherein the length (Ls) occupied along the rod (1) by a first block (12) is smaller than the length (Lb) occupied along the rod by a second block (11), the first blocks thereby providing a finer position indication than the second blocks. The first blocks (12) of barcode symbols can be formed of …
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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 29, 2005 and granted February 3, 2015. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 29, 2025.
- Certificates of supplementary protection extend only drug patents, and it isn't classified as one.
- 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.