Patent GB-878786-A (GB)
Title: Edge seaming apparatus
IPC: B24B9/10
Filed: 1959-09-30
Abstract: 878,786. Grinding glass sheets. PITTSBURGH PLATE GLASS CO. Sept. 30, 1959 [Dec. 16, 1958], No. 33159/59. Class 60. An apparatus for removing the sharp peripheral edges of flat sheets of glass, such as those used in the manufacture of laminated windscreens, comprises a horizontal conveyer for the sheets, at least one pair of carriages movable transversely of the conveyer, each carriage having an abrasive belt and pulley system supported thereby and pivotable about a vertical axis and means whereby each belt and pulley system may be initially so positioned that the belt engages an edge of the sheet at a pre-determined location and follows the contour of the edge which it disengages at a further predetermined location. The apparatus comprises four abrading units S-1, S-2, S-3 and S-4, Fig. 6, the first pair engaging the opposite indexed edges of a sheet G-1 and the second pair being arranged alongside to similarly engage an identical sheet G-2 passing through the apparatus in parallel with the first sheet ; the apparatus may be limited to the treatment of a single line of sheets requiring only one pair of abrading units. A positive drive is imparted to the sheets in the direction of the arrows of, Fig. 6, or from left to right, Fig. 2, by a series of driven rollers 14 comprising the conyeyer ; vertically-mounted rollers 18 contact the edges of the sheets to locate them laterally. Adjustable pinch rolls 15 are located vertically above the conveyer rollers 14 at the treatment station, at which four identicallyconstructed abrading units are suspended from their associated transversely movable carriages 25, Fig. 3. A pivotally-mounted bracket 37 supports an abrasive-belt driving motor 47 below each carriage 25, the pivot pin 38 having a collar 42 secured to its lower end to which is attached a cable 51 and counterweight 53 ; the cable and weight, operating through a pulley 52, maintain contact between an abrasive belt 60 and the edge of the glass sheet G and bias the bracket 37 about its pivot. Stop members 46 and 49, Fig. 5, permit initial positioning of the unit relative to the carriage 25, the angular setting being effected by adjusting a split ring 48 about a stationary collar 34 ; a stop 30, Fig. 3, locates transversely the carriage 25. The initial setting is such that the belts 60 of units S-1 and S-3 each form an angle with the path of travel of a sheet G-1 substantially equal to the angle of the leading edges of the sheet relative to its direction of travel, engagement with the sheet first occurring at or near the front extremity. A pair of guide rollers 62, mounted on the abrasive belt pulley support and belt-tightener 61, engage and follow the edge of the glass sheet which is contacted by the abrasive belt 60 at an angle of approximately 45 degrees. The belt pulleys 57, 58 are mounted at the ends of the telescopic tubular tensioning member 61 which has an internal-adjustable spring 73; a screw 76 effects adjustment of the initial spring-loading of the member 61 which is rigidly attached by its outer tube 68 to the pivoted bracket 37 by supports 55, 56, Fig. 3. In modified constructions, the carriages 25 are each mounted on a monorail and spring- biasing means may be employed in place of the counterweight system described above. An additional treatment station may also be provided having abrasive belts operating at 90 degrees to the angle to the edge made by the other belts.