Patent Yard Sign in
Expired Canadian patentCanada

Extrusion process and apparatus using changeable fine filters

CA 1162011 A · Owner: Treficable Pirelli · Inventors: Simon, Claude M.

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

A first continuously operating extruder for an extrudable material is fed with filtered such material from a second extruder through a filter and a storage tank having means for applying pressure to the material in the tank. During replacement of a filter, the second extruder is stopped and, the flow of material out of the continuously operating extruder is maintained constant by blocking the passageway between the second extruder and the tank and by applying suitable pressure to the material in the tank until the filter is removed and replaced by a new filter. The blocking device may be separate from a holder for a pair of filters,both the blocking device and the holder being movable by a …

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 February 14, 1984. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 14, 2001.
  • 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 29, 1981
GrantedFebruary 14, 1984
Term endedFebruary 14, 2001
Patent numberCA 1162011 A
Classification (IPC)B29C48/69

Timeline

Timeline From CIPO dates

1982198419861988199019921994199619982000Application filedDec 29, 1981Patent grantedFeb 14, 1984Term endedFeb 14, 2001

Sources & verification

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