GB1113108A - Grinding and polishing method and apparatus - Google Patents

Abstract

1,113,108. Abrading. CORNING GLASS WORKS. 24 May, 1965 [1 June, 1964], No. 21874/65. Heading B3D. A method for finishing a contoured surface of a frangible article, such as a TV panel, comprises rotating the article 65 to be finished about an axis perpendicular to a tangent centrally contacting the contour of the surface to be finished, and moving a contoured continuous work surface 26 over the rotating surface to be finished. The work surface may be in the form of a solid contoured rim or a plurality of liners of flexible material, such as neoprene, neoprene and cork or sizal, woven fabrics and rubber, felt on rubber, coated abrasives including diamondcoated mesh, or walrus hide, secured to the inner surface of a contoured rim 24 of a drum 23 mounted on a spindle 20 rotated by a belt drive 34, 37 from a variable-speed electric motor 33, the contour of the rim having a radius substantially equal to the radius of the drum. The article 65 is mounted on a workholder 64 supported by a shaft 63 connected by a rightangle drive unit 62 to a shaft 60 which is rotatable by a belt drive 57 from a motor 55 and is located at one end of a guide arm 58 rockable about a shaft 46 by a piston-and-cylinder device 69 connected by universal joints 67, 73 to the frame of the machine and the guide arm. The motor 55 and guide arm are mounted on a platform which is movable along the shaft 46 by a piston-and-cylinder device from an operating position, in which the article can be engaged with the work surface 26, to an inoperative position (indicated by dotted lines) in which the article can be mounted on the work holder 64. Pumicing or polishing slurry is supplied from a tank by a pump through a pipe to the interior of the drum and can pass through a slit 25 or other drainage openings in the drum into an outer shell 27 having a drainage opening leading to the tank, a mixer maintaining the slurry homogeneous. In another embodiment, the machine has three rotating workholders disposed within the rotating drum and indexable to bring the workholders successively to an unloading station wherein the tables can be retracted by piston-bellows arrangements and moved outwardly along slides. In a further embodiment, the rotatable work-holders are disposed within a frusto-hemispherical member and are mounted on a table which is indexable to bring the work-holders successively to an unloading position wherein they are slid inwardly along tracks.