GB439507A - Improved method of and apparatus for holding glass plate during tempering - Google Patents

Abstract

439,507. Tempering glass. PILKING- TON BROS., Ltd., Tower Building, Water Street, Liverpool, and FORBES, L. J. B., The Crossways, View Road, Rainhill, St. Helens, Lancashire. June 8, 1934, No. 17049. [Class 56] [See also Group XXX] A device for holding a glass plate during tempering comprises two pivoted members which are pressed against two opposite side edges of the plate so that they enter a predetermined distance into the glass as it softens, the pressure of the points on the glass then being released. The device comprises two carriages 3, one of which is shown in Fig. 1, both carriages being provided with screws 6 whereby they can be secured in any desired position on an horizontal bar 2. A lever, pivoted to each carriage at 9, has an horizontal arm 8 which carries a weight 11, and a depending arm 7 provided with a point or knife edge 10. The arm 8 is free to move between an upper stop 12 and a lower stop 13. In use, the two carriages are clamped in position on the bar 7 with the points 10 gripping the opposite side edges of the glass plate 1 while the arms 8 are against the upper stops 12. The weights 11 maintain sufficient pressure between the points 10 and the plate 1 to support it. As the glass softens during tempering, the weights 11 force the points into the glass until the arms 8 rest on the stops 13, thus releasing the pressure of the points on the glass. In another construction, shown in Fig. 3, a bell-crank lever 15, pivoted to the carriage 3, has one arm 14 furnished with a point 10 while the other arm has a forkedrecess which embraces a stop 19. When the lever is in the position shown, the lever arm 14 points upwards towards the glass sheet 1, and the weight of the sheet, gripped between the points 10 on two carriages, causes the points to press strongly against the edges. As the glass softens, the points 10 enter the glass until the side 18 of the forked recess meets the stop 19 when further movement of the lever is thus prevented. In another construction, shown in Fig. 4, the glass sheet 1 is supported in a frame composed of a bottom bar 20 to which side bars 21 are pivoted. The side members are suspended by hooks 27 from a bar 2, and they are also provided with pins 25 which enter slots 29 in a cross-bar 28, thus permitting limited movement of the members 21 to and from one another. Rods 30, having points or knife edges 10, are adjustably secured to the side members 21, and in operation, these points 10 are arranged to press against the edges of the sheet 1 when the pins 25 are at the outer ends of the slots 29. The hooks 27 are attached to the bar 2 in such a position that the weight of the frame presses the points 10 against the glass. When the glass softens, the points 10 enter until the pins 25 reach the inner ends of the slots 29 and thus release the pressure of the points on the glass.