GB1033654A - Process and apparatus for the hot enamelling of glass - Google Patents

Abstract

In the hot enamelling of glass, enamel powder is distributed from a hopper in a layer on an endless moving belt from which it is discharged due to collapse of the powder at the front of the layer at a turn of the belt on to glass having sufficient temperature to cause the <PICT:1033654/C1/1> <PICT:1033654/C1/2> powder to melt, the glass moving transversely of the falling powder at a speed greater than that of the belt. As shown in Figs. 1 and 3, enamel powder is in a hopper 10 with lower opening adjustable by nuts 14, 14a on eyenut 13 by which one side 11 is secured to the framework 12, the powder being deposited on an endless rubber belt 9 passing around shafts 5, 8 adjustable to maintain tension in the belt. Half bricks B of glass are passed on a conveyer belt 16 from the moulding unit to a further unit where they are joined together to form the final bricks, each brick B passing under the belt 9 to receive a coating of enamel powder on the inside which is melted by the heat of the moulded glass. A mash 23 is shaped to cover the edges of the brick B and has an outer channel to collect excess powder and a sieve 24 through which the powder falls on to the brick B. The mash 23 has a projection 29 by which it is carried along by a brick. The mash 23 is mounted by arms 22 on a sleeve 19 sliding on a rail 17 alongside the conveyer 16, the sleeve being maintained central by rollers 20, 21 but also being pivotable by a counterweight 26 on a bar 25 to raise the mash 23 at the end of the enamelling cycle to allow the enamelled brick to pass onwards while the mash 23 is returned for the next brick by the engagement of the pivoted bar 25 with the continuously rotated roller 32, the mash 23 being maintained horizontal by a roller 27 on an electromagnet 28 for the forward movement and returned to the horizontal by a roller 34 before passing under belt 9. Contractors 30 and 31, closed by the sleeve 19, energize and deenergize the electromagnet 28 respectively. The belt 9 is driven only when the brick B and mash 23 are passing below by means of a screen 35 on bar 25, cutting-off a beam of light energizing a photo-electric cell 36 to actuate a clutch 37 between shaft 5 and a motor unit 2, an electromagnetic brake 38 being operated and the clutch 37 disengaged when the beam of light is restored. A relay system prevents actuation of the clutch 37 on the return of the mash 23. The enamelling apparatus can be applied to drawn glass (Figs. 7 and 8, not shown), when no mash is used but the process is continuous and the enamelled glass may then be corrugated by rollers engaging the glass over a fluted table.