Central hubs for flexible magnetic data discs formed of magnetically soft polyacetal compositions
CA 2063871 C · Owner: Hughes, Patrick M. · Inventors: Hughes, Patrick M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Flexible sheet-like magnetic discs (so-called "floppy discs") are provided with a central hub formed of a magnetically soft polyacetal composition. The polyacetal composition necessarily includes a polyacetal resin and elemental iron particles homogeneously dispersed throughout the polyacetal resin in an amount sufficient to impart the desired soft magnetic properties to the inherently nonmagnetic polyacetal bane resin. The polyacetal compositions of this invention are infection-moldable so that central hubs for flexible magnetic discs can be rapidly and economically produced.
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 March 24, 1992 and granted February 12, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 24, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 24, 2014.
- 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.