Mercury and lead free high pressure sodium lamp
CA 2261380 A1 · Owner: Plumb, John L. · Inventors: Dolan, Robert B.; Plumb, John L.; Wyner, Elliot F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A long-life, environmentally disposable high pressure sodium lamp comprising: an arc, tube capable of withstanding internal wall temperatures of 1250 to 1300°C and having, electrodes sealed therein and being designed for operation at a given wattage; a, discharge space within the arc tube and an arc generating and sustaining medium within, the discharge space, the medium being mercury-free and containing sodium in an amount of about 0.02 mg to 0.06 mg/watt of designed operation and xenon at a , pressure, of 100 to 200 Torr; mounting means supporting the arc tube within a glass outer, envelope, the glass outer envelope being lead-free and arsenic-free; and an electrically, conductive …
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 February 8, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 8, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 8, 2021.
- 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.