GB1073808A - Blower chests for tempering glass - Google Patents

Abstract

Apparatus for the differential tempering of sheet glass, especially curved sheet glass for windscreens, comprises two main blower chests 1, 1a positioned one on each side of the sheet 34 from which jets of air are directed into the glass, one or both of the main chests 1, 1a being provided with at least one secondary blower chest 2 and/or 2a from which jets of air can be directed on to the glass at a pressure different from that of the jets of the main chests, the chests 2 and/or 2a being supported by the main chests 1, 1a by means which allow relative motion between the main and secondary chests. Preferably the secondary chests 2, 2a are mounted in housings 3, 3a for horizontal reciprocating movement on slide rails 19, 19a giving movement at right angles to the normal vertical reciprocating movement of the main chests, which are guided on rails 18, 18a by rollers 17, 17a. Both movements are produced by a motor 16 from driving shaft 13 through <PICT:1073808/C1/1> appropriate linkage. The air under pressure is supplied to the main chests 1, 1a through ducts 4, 4a by bellows 5, 5a connected to a fan, not shown, and the secondary chests 2, 2a are connected by separate pipes 32 to the air ducts 4, 4a so that the pressure can be regulated independently. The nozzles of the main chests 1, 1a and the nozzles 38 of the secondary chests 2, 2a are regulated so as to lie equidistant from the glass sheet and the nozzles 38 are preferably spaced further apart than the nozzles of the main chests. The frequency of the movements of the two sets of chests may be the same or they may be varied by adjustment of eccentrics to give variable or complicated paths to the jets. The chests may be independently driven.