Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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A procedure and apparatus for the production of wired glass by rolling.
The present invention refers to a procedure and an apparatus for
the manufacture, by rolling, of reinforced glass ribbon or layer, particular~
ly of glass ribbon reinforced with wire netting. ;
In known processes for the production of such rolled wire glasæ,
the molten glass is fed from a furnace between the rolls of a rolling mill,
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immediately upstream of which the wire netting is introduced into the mass
of fluid glass and entrained by the feed movement of the ribbon, which forms
dawnstream of said rolls, into which ribbon said metal netting is
incorporated.
Thiæ process involves, however, various draw-backs. In particular, ;
only a net with square or generally rectangular meshes may conveniently be
utilized as a reinforcement, with the warp wires necessarily running parallel
to the feed direction of the vitreous ~ass, inasmuch as any other geometric ~ ;
arrangement in which the wires would be at an angle with respect to this
direction would be sub~ected to a considerable strain due to the pull to
which the net is subjected, This would also lead to an increase in length i~
and to a reduction in width of the net. After its immersion into the
vitreous mass, the net must in fact pass through layers of molten glass
~20 upstream of the rollers, a~d these layers move at a speed lower than the
ribbon formed downstream of the rollers and incorporating the net, and
therefare the latter meets a considerable resistance. ,;
However, even wire nets with square or; g~nerally rectangular
meshe~ are sub~ected to a slight strain, with the result that these wires
become curved.
Another disadvantage is that the material of the netting suffers
an alteration of its initial strength owing to stretching.
In order to obviate the above mentioned drawbacks, a known process
for abtaining glass ribbons with reinforcements of any shape and arrangement
3Q ccns~iat~ in placing ~aid reinforcement between two separatel~ formed glass
layers placed one atop the other and pressure welding them.
It is clear that this process is rather expenaive and requires a
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considerable auxiliary equipment, which becomes particularly costly where
large size glass sheets have to be produced.
It is the ob;ect of the present invention to provide a process
and an apparatus which, although using the normal equipment for the manu-
facture of rolled glass sheets, permits the production of wired glass with
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nettings of any shape and arrangement, while reducing deformation of the ~
netting or reduction of strength of its material. A further object of the ~-
invention is to provide a process and an apparatus which is manifestly -
cheaper than the processes so far used for this purpose.
The invention provides in a process for the production of wired
glass by rolling, wherein a reinforcement is fed into a mass of molten
glass upstream of a pair of rollers in a rolling machinery, said rollers
cooperating to issue a ribbon of glass, the step of initially feeding said
reinforcement into said molten mass at a rate higher than the speed of the
ribbon of glass issuing from said rollers so as to form upstream of said
rollers a region of slack in said molten mass, and thereafter adjusting the
feed rate of said reinforcement to the speed of said ribbon of glass to main-
tain said region of slack in said molten mass.
ln this manner, the reinforcement is entrained by the glass ribbon
without any mutual displacement and strain between the ribbon and the rein-
forcement, with the result that wire netting of any desired mesh shape and
warp direction may be used as a reinforcement for the glass.
According to a preferred embodiment oE the invention, the kinetic
energy of the whirling motion produced by the rotation of the rollers in the
molten glass upstream of the rollers is used to -Lmpart to the reinforcement
a forward thrust in the interior of the glass. For this purpose, the rein-
forcement is introduced into the mass by the action of said whirl.
From another aspect, the invention provides apparatus for producing
wired glass by rolling, wherein a meshed reinforcement is introduced into a
single glass layer without subjecting the meshes of the reinforcement to
tensile deformation, said apparatus comprising: means for feeding a molten
glass mass to a pair of forming rolls; means for rotating said forming rolls
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to produce a uniform glass layer; feed means for introducing said reinforce-
ment into said molten glass mass well upstream of said forming rolls, said
feed means comprising a pair of feed rolls driven independently of said form-
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ing rolls and operative to introduce said reinforcement to said molten glass
mass at a speed such as to provide a region of slack in said reinforcement
in said molten glass mass, thereby to minimize tension forces in said rein- ~;
forcement before said reinforcement is drawn between the forming rolls.
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For purely illustrative and in no way limitative purpose embodi-
ments of the invention will now be described with reference to the attached
drawing, wherein:
figure 1 shows schematically a conventional procedure for the
~, production of wired glass; ~ -;
figure 2 shows schematically a first embodiment of an apparatus
and procedure Eor producing wired glass according to the invention; and
figure 3 shows also schematically a second embodiment of the
apparatus and procedure for producing wired glass according to the invention.
With reference to figure 1, there is indicated at 1 a mass of glass
in the fluid state which issues from the furnace 2 and flows in the runner
trough 3 towards the rolls 4 and 4' of a rolling mill which revolve in the
sense indlcated by the arrows. The mass of molten glass 1, when passing
through the rolls, is reduced to a single layer or ribbon 5, which, supported
by rollers 6, travels towards an area 7 of successive treatment. ;~
In conventlonal procedures, in order to provide the glass ribbon
! with a reinforcement, such as a metal net 8, the latter, which is fed from a
~¦ source not shown, comes in contact with the fluid mass of glass 1 in the - ;
vicinity of the upper roll 4 through a guide means 9, which is shaped and
directed in such a manner that the net 8 is passed by the feed movement of
the glass mass 1 through the rolls 4 and 4', thereby remaining incorporated
within the ribbon 5, whose movement causes the entrainment of the net 8.
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As previously mentioned, owing to the tensile stresses to which the
net is subjec~ed, this process permits only the use of nets with square or
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generally rectangular meshes, with the warp wires arranged parallel to the
feed direction of the glass. :
In the procedure according to the invention shown in figure 2, the
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wire net is introduced into the glass mass 1 a~ a point which lies further
upstream of the point at which it is introduced in the conventional processes
as shown in figure 1. Furthermore, while in the conventional procedure the
rate at which the metal net is introduced into the glass mass 1 is equal to
the speed of the ribbon 5, inasmuch as it is determined by the entraining
actian of the ribbon 5, in the procedure according to the present invention
the rate at which the net 8 is introduced into the glass mass 1 is varied, by
a suitable feed apparatus, so as to be initially higher than the speed of
the ribbon 5, with the consequence that a predetermined region of slack 10
is for~ed in the reinforcement net 8 within the fluid glass mass 1. Once
the region of slack 10 has been formed, the rate at which the net is fed
into the fluid glass mass 1 is reduced to the speeds of the ribbon S.
Therefore the net 8 moves together with the mass of molten glass
1 at the same speed reached by the latter in the space between the rollers,
without any displacement and stress between the glass and its meshes and
therefore without being subjected to tensile stress, thereby permitting the ` ;
use of wire nets shaped and arranged in any desired manner, without any
deformation of the latter.
A device with entraining and guide rolls 11 may be used as a feed
2~ device for producing the desired variation of feed rate of the net into the
mass of molten glass 1.
The net 8 may be fed into the glass mass 1 either vertically, as
sho~n in the drawings, or at a given angle with respect to the vertical.
In the embodiment shown in Eigure 3, the po-lnt at which the
reinforcement 8 is introduced in the molten mass of glass 1 is selected in
the ~icinity of the upper roll 4 of the rolling mill and precisely in the '
region where the mass 1 forms a whirl 12, in such a manner that the revolving
motion of said whirl 12 acts in the sense of imparting to the reinforcement
a thrust in the feed direc~ion. This contribu tes to avoid tensile forces `~3Q being caused upstream of the rolls in the elements forming the reinforcement
8, due to the entraining action of the ribbon 8 and involving a deformation
of the reinforcement.
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It is clear that even existing equipment for the production of
wired glass may be adapted for carrying into practice the hereinbefore .
described procedures, on the condition that they are augmented by a device :
by which the feed rate of the reinforcement into the molten mass upstream `.
of the rolls may be varied in the above described manner, in order to
produce and maintain a region of slack in the reinforcement upstream of the
rolls. :
It is also clear that the invention comprises also the wired glass
produced according to the above described procedures, since in the wired
glass produced by them the deformation of the net and the stresses between
glass and ~ire net are completely absent.
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