Electrostatic spraying device and method
CA 2047853 C · Owner: Imperial Chemical Industries Plc · Inventors: Reed, Brian; Noakes, Timothy J.; Chambers, John J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An electrostatic spraying device in which liquid emerging from an outlet of the device nozzle (12) is subjected to an electrical field sufficiently high for the liquid to be drawn from the outlet as one or more ligaments which break up into charged droplets to form the spray. The device is adapted for the spraying of targets which are conventionally difficult to coat electrostatically, eg. targets of insulating material. This is achieved by the use of circuitry (18 20, 22, 24) which generates a bi-polar high voltage output having a frequency such that successive clouds of particles are charged with opposite polarity but do not discharge each other in flight. In this way the charge, applied …
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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 July 25, 1991 and granted November 19, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 25, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 25, 2013.
- 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.