Method of scoring glass using a scoring wheel having an arcuate scoring surface
AssigneePPG Industries, Inc.
InventorEdmund R. Michalik
Life of this patent
Estimating the term…
Abstract
Pieces of glass are scored using a scoring wheel having a major radius (R.sub.1) and an arcuate scoring surface (R.sub.2) forced against the piece at a predetermined pressure. Thereafter, the score is opened by applying heat to the score and/or a bending moment about the score.
Claims13
In a method of scoring a refractory material selected from the group consisting of glasses, ceramics and glass-ceramics wherein the method includes the steps of contacting a surface of the refractory material with scoring means;
- providing relative movement between the scoring means and the piece of refractory material, while applying pressure to the scoring means to provide the refractory material with a score along a predetermined score path, the improvement comprising:
- the imposing an indentation in the surface, the indentation during scoring has a substantially constant predetermined radius of curvature along its depth when viewed through an intersecting plane normal and transverse to the score path
In a method of severing a piece of refractory material selected from the group consisting of glasses, ceramics and glass-ceramics wherein the method includes the steps of contacting a surface of the piece with scoring means;
- applying a pressure to the scoring means;
- displacing the scoring means and piece relative to one another to provide the piece with a score along an intended path of cut;
- and extending the score between opposed surfaces of the piece to sever the piece, the improvement comprising the steps of:
- imposing a score including (1) an indentation in the surface, the indentation during scoring has a substantially constant predetermined radius of curvature along its depth when viewed through an intersecting plane normal and transverse to the intended path of cut and (2) a fracture below the indentation.
An apparatus for scoring a piece of refractory material selected from the group consisting of glass, ceramics or glass-ceramics, comprising:
- means for supporting the piece;
- a scoring means having a circumferential arcuate scoring surface, the cross-section of the arcuate scoring surface having a substantially constant predetermined radius of curvature when viewed in a plane containing rotating axis of said scoring means;
- means for urging said scoring means toward said supporting means under pressure;
- and
- means for providing relative motion between said supporting surface and the scoring surface to score the piece along an intended path of cut.
Dependencies are inferred from the claim text.