Patent Yard Sign in
Expired Canadian patentCanada

Sealed rotary hearth furnace

CA 1306605 C · Owner: Johnson, Beverly Earl · Inventors: Docherty, James P.; Johnson, Beverly Earl

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 furnace has a hearth which rotates inside a stationary closed chamber and is supported therein on circumferentially spaced rollers the shafts of which extend outside the furnace wall and are cantilevered in bearings. The shafts are sealed to the furnace wall by mechanical and pressurized gas sealing means. The charge is deposited through the furnace roof on the rim of the hearth as it rotates and is moved toward the center of the hearth by rabbles. Externally generated hot gases are introduced into the furnace chamber below the hearth and rise through perforations in the hearth and up through the charge. Exhaust gases are withdrawn through the furnace roof. Treated charge drops from 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 August 25, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended August 25, 2009.
  • 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, 1988
GrantedAugust 25, 1992
Term endedAugust 25, 2009
Patent numberCA 1306605 C
Classification (IPC)F27B3/06 +2 more

Timeline

Timeline From CIPO dates

1989199219951998200120042007Application filedDec 29, 1988Patent grantedAug 25, 1992Term endedAug 25, 2009

Sources & verification

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