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Expired Canadian patentCanada

Blind-taper hole saw

CA 2255273 C · Owner: Wise, Michael A. · Inventors: Wise, Michael A.

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A rotary tool for forming a blind-tapered hole in a workpiece includes an elongate shaft having a bit shank on one end and a base plate secured to the other end. A collar mounted for axial movement on the shaft is biased away from the, base plate to a first position on the shaft by a return spring. At least two cutting blades are pivotally attached to the collar. A portion of the length of each cutting blade is fixedly circumferentially and radially supported relative to the shaft by a blade guide that rotates with the shaft such that the angle formed between each cutting blade and the shaft's rotational axis increases with increasing axial displacement of the collar on the shaft away from …

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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 2, 1998 and granted February 19, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 2, 2018.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 2, 2020.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledDecember 2, 1998
GrantedFebruary 19, 2002
Term endedDecember 2, 2018
Patent numberCA 2255273 C
Classification (IPC)B23B41/06 +2 more

Timeline

Timeline From CIPO dates

1999200120032005200720092011201320152017Application filedDec 2, 1998Patent grantedFeb 19, 2002Term endedDec 2, 2018

Sources & verification

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