Drainage unit with controlled negativity relief feature
CA 2223744 C · Owner: Weilbacher, Eugene E. · Inventors: Swisher, David R.; Weilbacher, Eugene E.; Yam, Jacky S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides for an improved airflow sensitive float valve (38) interposed between the collection chamber (15) and one arm of the water seal chamber (16) for allowing the patient to draw as much vacuum pressure as is required during deep inspiration. The float valve also functions to provide for an automatic controlled release of excess negtive pressure in the collection chamber during either continuous auto-transfusion or when there is a low airflow rate condition present. By tailoring a specific amount of water to a given size chamber, the water column inside the water seal chamber is allowed to momentarily engage the floating mechanism before the water seal chamber is …
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 June 7, 1996 and granted October 7, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 7, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 7, 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.