Electrode for metal halide discharge lamp
CA 2076629 C · Owner: Welch Allyn, Inc. · Inventors: Scoins, John; Graham, Timothy W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A low-wattage metal-halide discharge lamp (10) has a quartz tube (12) of the double ended type hat forms a bulb (14) or envelope a pair, of electrodes, e.g. an anode (30) and a cathode (32) which penetrate in-, to an arc chamber (16) inside the envelope(14) and a suitable amount, of mercury (98) pies one or more metal halide salts. The electrodes (30 32) are each formed of a refractory metal i.e. tungsten wire, extending, through the respective necks (22 24) info the arc chamber (16). The electrodes (30, 32) are of a composite design i.e. in the form of a club with, a lead-in wire (34;44) of mall diameter supported in the quartz (12) in the associated neck (22; 24), and a post member (36; …
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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 December 30, 1991 and granted September 10, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 30, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 30, 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.