Writing instrument
CA 2007243 C · Owner: Chuang, Cheng-Hwa · Inventors: Chuang, Cheng-Hwa
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
14, A writing instrument in which plural cartridges are fitted and coupled in series with each other in their longitudinal direction so that the cartridges are removable from each other. Each of the cartridges comprises a tubular body having a tubular projection at one end of the tubular body and having an optionally shaped cross section, and a core unit inserted in the tubular projection so that the core unit is held in it. The tubular body has an insertion hole into which the tubular projection of the adjacent cartridge which is, coupled to the tubular body, is fitted in the longitudinal direction of each cartridge so that the tubular projection is held in the insertion hole removably …
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 January 5, 1990 and granted July 21, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 5, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 5, 2012.
- 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.