Method and apparatus for removing peripheral portion of a glass sheet

Abstract

Process for removing peripheral portions such as bead regions of a glass sheet including a step of pushing the glass sheet in the peripheral portion using a pushing mechanism such as a pushing bar, and corresponding apparatus. As a result of the use of the pushing mechanism, the engagement completion time for suction cups, if used, are reduced significantly. A process without using suction cups is enabled with enhanced yield. The increased process stability and enlarged process window are particularly advantageous for processing glass sheets having high flexibility.

What is claimed is: 
     
         1 . An apparatus for removing a first peripheral portion of a glass sheet having a first major surface, a second major surface opposing the first major surface, a center region having a center thickness Th(C), an upper edge surface, a lower edge surface, a first side edge surface and a second side edge surface, each edge surface connecting the first major surface and the second major surface, and the first peripheral portion in the vicinity of the end of the first side edge surface, comprising the following:
 (A) a glass suspension device adapted for placing the glass sheet in a vertical position by restraining the first and second major surfaces in the vicinity of the upper edge surface;   (B) a first side edge restraining tower located on the side of the first major surface comprising a first side edge restraining clamp strip, and a second side edge restraining tower located on the side of the second major surface comprising a second side edge restraining clamp strip, the distance between the first side edge restraining clamp strip and the second side edge restraining clamp strip being adjustable and adapted for restraining the first and second major surfaces in the vicinity of the first side edge surface at a distance D1 from the end of the first side edge surface extending from the upper edge surface to the lower edge surface;   (C) a mechanical scoring wheel installed on the first side edge restraining tower adapted for vertical motion in contact with the first major surface to form a score-line on the first major surface extending from the vicinity of the upper edge surface to the vicinity of the lower edge surface at a distance from the end of the first side edge surface D2, where D2<D1;   (D) a straight, vertical bar adapted for pushing the first major surface towards the second major surface;   (E) a plurality of suction cups adapted for engaging the second major surface of the first peripheral portion at a distance from the end of the first side edge surface D3, where D3<D2;   (F) a nosing strip opposing the score-line adapted for contacting the second major surface; and   (G) a force applicator adapted for pulling the second major surface in a direction away from the first major surface by the suction cups, such that the first peripheral portion of the glass sheet in the vicinity of the first side edge surface bends against the nosing strip, and separates along the score-line from the center region of the glass sheet.   
     
     
         2 . An apparatus according to  claim 1 , wherein the nosing strip has a Shore A hardness not lower than the glass sheet. 
     
     
         3 . An apparatus according to  claim 1 , wherein the nosing strip is supported by a seat that is sufficiently rigid such that the nosing strip remains substantially linear when the score wheel presses the first major surface of the glass against the nosing strip. 
     
     
         4 . An apparatus for removing a first peripheral portion of a glass sheet having a first major surface, a second major surface opposing the first major surface, a center region having a center thickness Th(C), an upper edge surface, a lower edge surface, a first side edge surface and a second side edge surface, each edge surface connecting the first major surface and the second major surface, and the first peripheral portion in the vicinity of the end of the first side edge surface, comprising the following:
 (A) a glass suspension device adapted for placing the glass sheet in a vertical position by restraining the first and second major surfaces in the vicinity of the upper edge surface;   (B) a first side edge restraining tower located on the side of the first major surface comprising a first side edge restraining clamp strip, and a second side edge restraining tower located on the side of the second major surface comprising a second side edge restraining clamp strip, the distance between the first side edge restraining clamp strip and the second side edge restraining clamp strip being adjustable and adapted for restraining the first and second major surfaces in the vicinity of the first side edge surface at a distance D1 from the end of the first side edge surface from the upper edge surface to the lower edge surface;   (C) a mechanical scoring wheel installed on the first side edge restraining tower adapted for vertical motion in contact with the first major surface to form a score-line on the first major surface extending from the vicinity of the upper edge surface to the vicinity of the lower edge surface at a distance from the end of the first side edge surface D2, where D2<D1;   (D) a straight, vertical bar adapted for pushing the first major surface towards the second major surface; and   (E) a nosing strip opposing the score-line adapted for contacting the second major surface.   
     
     
         5 . An apparatus according to  claim 4 , wherein the nosing strip has a Shore A hardness not lower than the glass sheet. 
     
     
         6 . An apparatus according to  claim 4 , wherein the nosing strip is supported by a seat that is sufficiently rigid such that the nosing strip remains substantially linear when the score wheel presses the first major surface of the glass against the nosing strip.