Process and apparatus for producing glazed ceramic tiles, and tiles so obtained

Claim 1

An apparatus for firing and glazing clay tiles, comprising a firing furnace having a first section with a first inlet mouth for receiving dried raw clay tile, means in said first section for gradually heating raw tiles as they pass through said first section to a temperature sufficient for substantially completing firing reactions in the clay tile and for raising the temperature of the tiles to an incandescent plastic temperature, said first section having a first exit mouth for discharging the tile at the incandescent plastic temperature, a glazing section for receiving fired tiles at the incandescent plastic temperature directly from said first exit mouth, means in said glazing station for permitting an abrupt drop in temperature of said fired tiles to a temperature below a vitrification temperature of a dry loose glaze, glaze spreading means in said glazing station for spreading dry loose glaze on the fired tile in said glazing station, said firing furnace having a second station with a second inlet mouth for receiving glaze covered tiles from said glazing station, means in said second section for maintaining tiles in said second section at an initial temperature sufficient for vitrifying the glaze on the tiles and for providing a subsequent controlled and decreasing temperature for the progressive cooling of the tiles in said second section, said second section having a second exit mouth for discharging glazed, fired and cooled tiles, and conveying means extending in a single pathway through said first section, said glazing station and said second station, and past said first and second inlet and said first and second exit mouths, for conveying tiles from said first inlet mouth to said second mouth so that raw tiles are fired and glazed in a continuous process.

Claim 2

An apparatus for firing and glazing clay tiles, comprising a firing furnace having a first section with a first inlet mouth for receiving dried raw clay tile, means in said first section for gradually heating raw tiles as they pass through said first section to a temperature sufficient for substantially completing firing reactions in the clay tile and for raising the temperature of the tiles to an incandescent plastic temperature, said first section having a first exit mouth for discharging the tile at the incandescent plastic temperature, a glazing section for receiving fired tiles at the incandescent plastic temperature directly from said first exit mouth, means in said glazing station for permitting an abrupt drop in temperature of said fired tiles to a temperature below a vitrification temperature of a dry loose glaze, glaze spreading means in said glazing station for spreading dry loose glaze on the fired tile in said glazing station, said firing furnace having a second station with a second inlet mouth for receiving glaze covered tiles from said glazing station, means in said second section for maintaining tiles in said second section at an initial temperature sufficient for vitrifying the glaze on the tiles and for providing a subsequent controlled and decreasing temperature for the progressive cooling of the tiles in said second section, said second section having a second exit mouth for discharging glazed, fired and cooled tiles, and conveying means extending in a single pathway through said first section, said glazing station and said second station, and past said first and second inlet and said first and second exit mouths, for conveying tiles from said first inlet mouth to said second mouth so that raw tiles are fired and glazed in a continuous process.