GB824457A - Improvements in method and apparatus for cutting glass sheets - Google Patents

Abstract

824,457. Cutting glass sheets. PITTSBURGH PLATE GLASS CO. Aug. 23, 1957 [Sept. 24, 1956], No. 26678/57. Class 56. In a glass-cutting apparatus, ultrasonic vibrations, preferably of frequency between 20 and 80 Kilocycles per second, are imparted to the cutting wheel 30 in a direction normal to its axis of 'rotation. The wheel, which may be of tungsten carbide, is carried by a conical member 26 brazed to a coupling bar 22 which is brazed to a transducer 14 which may be of the piezoelectric or magnetostrictive types. This assembly is locked by a flange 24, coincident with the node of the vibrations, to a housing 44 which is non-rotatably mounted in a piston 50 which can be depressed against a spring 78 by air pressure admitted at 82 to lower the cutting wheel into contact with the glass 6 with a pressure of between 10 and 30 1bs (preferably 12 to 20). Cooling air for the transducer is supplied through pipe 66 and discharged at 74. The edge of the wheel is V-shaped with an included angle of between about 135 and 168 degrees (preferably 139-166). The thickness of the wheel is between 1/32 and 5/32 inch and its diameter between 3/16 and 5/16 inch. The relative movement between the wheel and the glass sheet is between 5 and 70 (preferably 9 and 25) feet per minute. Details are given of the results obtained on different types and thicknesses of glass using different variables such as speed, frequency, and included angle of the wheel edge. Specification 602,801 is referred to.