Two stage vacuum cleaner filter
CA 2193008 C · Owner: Hult, David R. · Inventors: Kolehmainen, Donald M.; Young, Jeffrey L.; Hult, David R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A two stage vacuum cleaner filter is disclosed. The filter includes a first stage outer filter extending in a closed circumferential path with a second stage inner filter located in immediate proximity to and within the first stage outer filter. Sealing elements for securing opposite ends of the first stage outer filter and second stage inner filter to each other are provided. The second stage inner filter stops particles that might leak through the first stage outer filter.
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 December 16, 1996 and granted September 5, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 16, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 16, 2018.
- 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.