Glass-ceramic plates, method of manufacturing them and hobs equipped with these plates

Abstract

A glass-ceramic plate, a method of manufacturing a glass-ceramic plate, and hubs equipped with the glass-ceramic plate. A flat or substantially flat glass-ceramic plate includes a surface provided with pegs, the plate configured to equip a hob. At least one smooth region, free of pegs, is reserved in a location designed to come, in a mounted position, face to face with one or more elements of the hob, the blurred view of which due to the pegs must be improved.

1 . A process for manufacturing a glass-ceramic plate comprising:
 providing a rolling device including two rollers between which molten glass to be rolled is passed;   obtaining a ribbon whose length corresponds to one or more plates by passing the molten glass between the two rollers, one of the rollers including a surface with pegs, wherein the roller with pegs includes at least one smooth region free of pegs, the at least one smooth region on the surface of the roller being dimensioned and positioned to form, during rolling, at least one peg-free region on a surface of the ribbon, the peg-free region on the surface of the ribbon being dimensioned and positioned to be, after an operation of cutting the ribbon into plates having final dimensions, face to face with one or more elements of a hob on which the plate is intended to be placed.   
     
     
         2 . The process according to  claim 1 , for manufacturing a glass-ceramic plate, wherein the peg-free region of the roller includes a strip or a portion of a cylindrical strip located proximate to an edge of the roller to obtain a peg-free strip parallel to an edge of the plate. 
     
     
         3 . An apparatus for manufacturing a glass-ceramic plate, comprising:
 a rolling device including first and second rollers between which molten glass to be rolled is passed to obtain a ribbon whose length corresponds to one or more plates, the first roller including a surface with pegs,   wherein the first roller includes at least one smooth region free of pegs, the at least one smooth region on the surface of the roller being dimensioned and positioned to form, during rolling, at least one peg-free region on a surface of the ribbon, the peg-free region on the surface of the ribbon being dimensioned and positioned to be, after an operation of cutting the ribbon into plates having final dimensions, face to face with one or more elements of a hob on which the plate is to be placed.   
     
     
         4 . The apparatus as claimed in  claim 3 , wherein the peg-free region of the first roller includes a strip or a portion of cylindrical strip located proximate to an edge of the roller, the strip or portion of a cylindrical strip being configured to form a peg-free strip on the plate parallel to an edge of the plate. 
     
     
         5 . A process for manufacturing a glass-ceramic plate, comprising:
 rolling molten glass between first and second rollers to obtain a ribbon whose length corresponds to one or more plates configured to fit a hob, the first roller comprising a surface with pegs and at least one smooth region free of pegs;   forming pegs on a surface of the ribbon with the first roller; and   forming at least one peg-free region on a surface of the ribbon with the first roller, the at least one peg-free surface dimensioned and positioned to overlap, after an operation of cutting the ribbon into plates having final dimensions, one or more one or more elements of a hob on which the plate is to be placed.   
     
     
         6 . The process according to  claim 5 , further comprising forming a peg-free strip parallel to an edge of the plate via a peg-free region of the first roller. 
     
     
         7 . The process according to  claim 6 , further comprising providing the peg-free region of the first roller as a portion of a cylindrical strip located proximate to an edge of the first roller.