Freeze indicator
CA 1111716 A · Owner: Akzona Incorporated · Inventors: Johnson, Claude D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
There is provided a freeze indicator comprising a frangible container. The container houses a liquid which expands upon freezing, thereby fracturing the container. The liquid includes a mixture of water and deuterium oxide. An indicator is responsive to the liquid being in close association with the frangible container. The indicator provides an indication of freeze at a predetermined temperature as determined by the percent composition of the mixture of deuterium oxide and water.
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
- Granted November 3, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 3, 1998.
- 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.