Patent Yard Sign in
Expired Canadian patentCanada

Finish measuring method and apparatus

CA 1134913 A · Owner: Micro Sensors, Inc. · Inventors: Piso, John S.; Roberge, James K.

CIPO record

Overview

Drawings and full text

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

Open the CIPO record

Abstract From the Canadian patent

The amount of electrically conductive finish that has been applied to a filament is determined by measuring the conductance of a length of the filament. The measurements are made independently of any differences in conductivity of finish mediums by means of a reference cell containing a sample of the particular finish medium used. An electric measurement circuit provides an indication of the amount of finish medium on the filament by determining the ratio of the conductance of the length of filament to the conductance of the reference cell. In one circuit embodiment, two operational amplifiers are placed in series. The reference cell takes the place of the feedback resistor of one …

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 2, 1982. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 2, 1999.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledApril 20, 1979
GrantedNovember 2, 1982
Term endedNovember 2, 1999
Patent numberCA 1134913 A
Classification (IPC)G01R19/00 +2 more

Timeline

Timeline From CIPO dates

1980198219841986198819901992199419961998Application filedApril 20, 1979Patent grantedNov 2, 1982Term endedNov 2, 1999

Sources & verification

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