Machine for drilling fragile sheet-like materials, in particular sheet glass and the like

A machine for drilling fragile sheet-like materials, in particular sheet glass or the like, comprising a feedin station for a sheet blank, a sheet blank drilling station, a drilled sheet discharge station arranged downstream to each other in aligned relationship and defining an advance direction of said sheet, said feed-in station including a frame, means for locating said sheet in a fixedly predeterminated reference zero position, a carriage for advancing said sheet to said drilling station as well as means for controllably driving said carriage to a variable, automatically adjustable position in said drilling station, said locating means comprising a plurality of at least partially driven rollers defining a support surface for said sheet, a motor unit for said rollers, an abutment member carried on said frame laterally to said feed-in station and substantially parallel to said advance direction as well as a pad element located in the advance path of said blank sheet and movable from a position of interference with said sheet above said sheet support surface to a position underlying said sheet support surface, said rollers having peripherally a shroud having ridges of high frictional coefficient with a helical pattern formed thereon for causing said sheet to move forward in said advance direction toward said pad element and transversely toward said abutment member, said carriage comprising gripper assemblies having fluid dynamic actuated jaws for gripping said sheet at edge portions thereof, said means for controllably driving said carriage comprising runways supported by and extending laterally to said feed-in station frame and a hearing screw transmission controlled by an angular transducer for carrying said sheet from said reference zero position to said variable, automatically adjustable drilling position, said drilling station including a drilling station frame, at least one drilling head pair overlying and underlying a working zone, means for driving said at least one drilling head pair transverse to said sheet advance direction, means for raising and lowering said at least one drilling head pair to and from said sheet, cooling means as well as waste discharge means cooperating with said at least one drilling head pair, each drilling head of said at least one pair comprising a substantially cylindrical pressure member slidably mounted on said drilling head and accommodating therein a respective independently driven tool bit, said pressure member being hydraulically connnected to a cooling fluid supply and a discharge conduit cooperating with a trough for directing the cooling fluid away from said working zone.