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Expired Canadian patentCanada

Multisensor piezoelectric elements and a method for making the same

CA 1317478 C · Owner: Singer Company (The) · Inventors: Wittke, Ernest C.; Rosen, Carol Z.

CIPO record

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Abstract From the Canadian patent

A piezoelectric sensing element is formed from bonding two piezoelectric layers with an intermediate metallic film. The intermediate metallic film is comprised of two separate films, which were sputtered onto the inner surfaces of the respective piezoelectric layers, which are then placed in contact with each other. The combination of piezoelectric layers and film is next heated at an elevated temperature for fusing the respective sputtered alloy films so that the piezoelectric layers are bonded into a piezo-pair sensor. The layers to be joined are chamfered so that the center electrode appears as a notch on the finished piezo-pair to allow a connection to the center electrode for poling …

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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

  • Granted May 11, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 11, 2010.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledSeptember 23, 1987
GrantedMay 11, 1993
Term endedMay 11, 2010
Patent numberCA 1317478 C
Classification (IPC)H01L41/04 +2 more

Timeline

Timeline From CIPO dates

19881991199419972000200320062009Application filedSep 23, 1987Patent grantedMay 11, 1993Term endedMay 11, 2010

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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.