IL40581A - Process and device for influencing the face configuration of vitreous or partly vitreous bodies by thermal treatmen - Google Patents

Abstract

1395987 Treating vitreous material GLAVERBEL 23 Oct 1972 [25 Oct 1971] 48783/72 Heading C1M A body of vitreous or partly vitreous material is treated in a gas-filled treatment chamber (other than the drawing chamber, or annealing lehr associated therewith, of a drawing machine), in at least one zone of which the temperature of at least one face of the body is sufficiently high for the geometry of that face to be influenced by the heat distribution in the gas, gas-displacing forces being exerted first in one direction and then in a reverse direction to cause the gas in the said zone to move to and fro in contact with the said face. Preferably the forces are exerted at at least 1 cycle in 10 minutes, and up to 10 cycles per minute. The chamber may be an annealing lehr 37 in which a glass ribbon or sheet 43 is supported on rollers 44. Transverse motion of the gas to and fro above the sheet is caused by alternate injection of gas from tuber 45 and 46, which are supplied with gas from reservoir 52 and distributer 51. The treatment is preferably carried out in the zone in which the glass has a temperature of 450-600‹ C. The gas injected may be preheated air, or may be a combustible gas. Mechanical means, e.g. propellers or reciprocating plates, may replace the injectors. In an alternative embodiment (Fig. 4, not shown) the gas-displacing technique is used in a process for bending glass sheets by sagging into a concave mould. [GB1395987A]

Claims (1)

1. WHAT IS CLAIMED A process in which a body of vi reous or partly vitreous material is treated in a treatment fully separated and distinct from a so as not to be subject to heat convection from such a machine in at least one zone of which the temperature of at least one face of said body is at or acquires a temperature which is sufficiently high for the configuration of that face to be capable of heat distribution in the gaseous atmosphere in that ng forces are exerted first in one direction and then in a reverse direction to cause gas in at least one said zone and in contact that face to move to and fro in contact with said face while the temperature of such in that is at said sufficiently high A process according to claim characterised in that said forces are exerted in at least one said zone at a frequency of more than 1 cycle every ten one cycle comprising a force exertion in one direction and a force exertion in a reverse A process according to claim 1 or wherein the chamber comprises entry and exit ends via which said body enters and exits from the characterised in that in at least one said zone said forces are exerted in directions transverse to the path of movement of the body into and out of the A process according to any preceding characterised in that in at least one said zone said forces are exerted in opposite directions across said and at positions which are 5 adjacent opposed side walls A process according to any preceding said body is a sheet or part of a continuous characterised in that there is at least one said zone in said forces are exerted to cause 10 said to and fro movement of gas substantially only on one side of such sheet or A process according to any of claims 1 to said body is a sheet or part of a continuous characterised in that there is at least one 15 said zone in which said forces are exerted to cause said to and fro movement of gas on each side of such sheet or A process according to any characterised in that there is at least one said 20 zone in which said forces are exerted by blowing gas into the atmosphere within the A process according to any preceding wherein said body is a sheet or part of a continuous in that the said sheet or 25 ribbon is annealed in said A process according to claim characterised in that said forces are exerted in at least one zone where the temperature of the or ribbon is in the range 600 to A process according to claim 8 or wherein said sheet or ribbon is a sheet or ribbon by the float process of manufactu ing flat glass and passes into while faces of the sheet or ribbon are still at a said sufficiently high A process according to any of claims I to said constitutes part of a sheet bending and said body is a sheet which is caused to permanently bent in such Apparatus use in performing a process according to suc apparatus comprising a treatment means for supporting a vitreous or partly vitreous body in said and means for heating the interior of the characterised in that means is provided for exerting forces first in one direction and then in a reverse direction to cause gas to move to and fro in at least one zone within said Apparatus according to claim wherein said chamber comprises entry and exit ends and there is means for conducting a bod through such characterised in that means is provided for said forces in at least one said in directions transverse to the path of movement along which a said body moves through the Apparatus according to claim 12 or in that means is provided for everting said forces in least one said in opposite directions across said chamber and at positions which are adjacent opposide side walls according to claim characterised in that ors are provided within said chamber and is provided for gas into said chamber e injection tubes of such so as to exert said forces in at least one said Apparatus according tc any of claims 12 to characterised in that means is provided for maintaining a temperature gradient within said chamber to permit the annealing of glass bodies tnerein and in that means is provided for exerting said displacing forces in at one where the temperature of a vitreous or vitreous body during annealing thereof in the chamber is in the range to Apparatus according to any of claims 2 to 16 wh said chamber is installed adjacent a float tank manu flat glass by the float process and means is provided for conducting sheets of glass or a continuous glass ribbon from such float tank into said chamber for annealing purposes Apparatus according to any of claims 12 to wherein said chamber is a bending chamber in which vitreous or vitreous to A of or partly vitreous material substantially as use in treating of vitreous or vitreous substantially as reference to ing A body vitreous or partly reous material has been treated a process according to any 1 to 11 and COHEN ZEDE Box 33116 for insufficientOCRQuality