Apparatus for manufacturing glazing panels

An apparatus for manufacturing a glazing panel which includes a pair of glazing sheets separated by an intervening marginal spacer frame formed to a required size and shape from strip material and marginally secured between the pair of sheets. The apparatus comprises a frame forming mechanism which includes guides defining at least two paths for feeding required lengths of the strip material, stops defining a position for the leading ends of the strip material as it is fed, a plurality of bending stations arranged to bend the strip material on at least one of the paths to form frame corner angles at required distances from the stops, and apparatus for joining the ends of spacer strip material which has been fed along the paths and bent, thereby to form the frame.

BACKGROUND OF THE INVENTION 
This invention relates to a method of manufacturing a glazing panel 
comprising a pair of glazing sheets separated by an intervening marginal 
spacer frame in which the spacer frame is formed of strip material and is 
marginally secured between the pair of sheets. The invention extends to an 
apparatus for performing the method and to hollow panels manufactured 
using the method. 
In the manufacture of glazing panels, it has hitherto been the usual 
practice to form a spacer frame in situ on a first sheet and then to apply 
a second sheet thereto to form a double panel unit. A further spacer frame 
may be formed on, and a third sheet may be similarly applied to, the 
second sheet if it is desired to form e.g. a triple panel unit. This 
procedure usually requires the use of highly skilled labour. 
SUMMARY OF THE INVENTION 
The present invention may be considered as having two aspects. The first 
aspect of the invention relates particularly to the formation of the 
spacer frame, and the second aspect to the positioning of a spacer frame 
on a glazing sheet. 
The present invention in its first aspect provides, as broadly defined, a 
method of manufacturing a glazing panel comprising a pair of glazing 
sheets separated by an intervening marginal spacer frame in which a the 
spacer frame is formed of strip material and is marginally secured between 
the pair of sheets. This spacer frame is formed by supplying the strip 
material in two or more separate lengths, bending at least one such length 
to form angles of such sizes and at such positions that a frame of the 
required shape and size can be formed by joining together the end portions 
of such lengths, and joining such end portions to form the frame. 
The present invention accordingly provides a method of mechanically forming 
a spacer frame for incorporation into a hollow panel unit which thus 
reduces the requirement for highly skilled labour and has other attendant 
advantages which are particularly apparent in series production. 
In preferred embodiments of the invention, the end portions are joined 
together in overlapping relationship. This simplifies sealing of the panel 
at the regions of the ends of the strip material. 
Preferably, the lengths of spacer strip material are brought together so 
that their ends overlap by the bending operation. This greatly facilitates 
the frame assembly operation. 
Advantageously, the overlapping end portions of spacer strip material are 
crimped together. This provides a temporary joint of sufficient strength 
to hold the frame together during its subsequent transfer and assembly 
between a pair of sheets. 
In preferred embodiments of the invention, the frame is formed from spacer 
strip material which has been folded along its length to provide a web 
portion for determining the inter-sheet spacing of the glazing panel into 
which it is to be incorporated, and at least one flange portion for 
attachment in face-to-face relation to a sheet of the panel. This feature 
has a beneficial effect on the structural rigidity of the frame prior to 
assembly between the sheets of the panel, and confers the further 
advantage of allowing an improved form of spacer-to-sheet joint to be 
formed. Optimally, said spacer strip material is of or is folded into 
channel form, having a flange for attachment to each sheet of the pair. 
In embodiments of the invention in which channel form strip material is 
used, it is especially preferred that the side walls only of the channels 
are crimped together at each zone of overlap. 
Where such flanged spacer strip material is used, it is preferred that, of 
each pair of overlapping end portions, the flange or each flange of one 
end portion is kinked to narrow the web of that end portion so that that 
end portion nests inside the other end portion of the pair when they are 
joined together. The adoption of this feature provides a more uniform 
surface for attachment to a sheet of the panel. 
Preferably, the strip material is bent by rolling it around a backing 
support while supporting the flange or each flange. This enables the 
flange or each flange to be maintained in planar form for attachment to a 
the sheet. It is especially suitable if the strip material is bent so that 
the flange(s) is stretched during the bending operation, since such 
support is thereby made easier. 
Advantageously, the web portion of the spacer strip material is deformed 
across its width at each bend, and preferably such deformation is effected 
progressively during the bending operation. This enables stresses which 
appear in the flange(s) as a result of the bending operation to be 
supported in a more predictable manner, so that a stable form of spacer 
frame can consistently be formed, and this is especially important in 
series production of hollow panels. 
The invention can be used in the manufacture of spacer frames of various 
shapes, for example, triangular or hexagonal frames for incorporation into 
correspondingly shaped panels, but the invention is particularly 
applicable to the manufacture of quadrilateral spacer frames, and 
especially to the manufacture of rectangular spacer frames. 
In the manufacture of a quadrilateral spacer frame, it is preferred that 
two lengths of spacer strip material are used to form the frame. 
In some embodiments of the invention, one such length of spacer strip 
material is bent four times to form quadrilateral frame corners while the 
other such strip remains straight, and in some other embodiments, there is 
one strip length which is bent once while the other is bent in three 
places. In the most preferred embodiments of the invention however, each 
length of strip material is bent in two places, because this simplifies 
the design of the bending apparatus. 
Advantageously, one length of spacer strip material is bent at two 
positions such that a short retaining limb of strip material leads from 
each such bend to each end of that length of material. A limb may for 
example be 2 to 15 cm long measured from the apex of such bend to the end 
of the length of spacer strip material. This enables the ends of the 
strips to be more easily held in a stable manner so that when they are 
brought together it is easier to join them in the desired manner. 
In general, for the size of hollow panel unit with which this invention is 
primarily concerned, that is, hollow panels whose shortest side is at 
least 20 cm long, the adoption of this feature enables that length of 
spacer strip material to be bent at positions which depend on one desired 
side length only of the panel, while the other strip is cut to length and 
bent at positions which depend on the desired lengths of the other three 
sides of the panel. This simplifies the apparatus required for the 
performance of the invention. One length of spacer can always be bent at 
positions located at predetermined distances from its ends, and these 
distances need not be changed no matter what size of panel is being 
manufactured, so that the apparatus for joining together the ends of the 
spacer strips can be in fixed location with respect to each of a pair of 
bending stations where such retaining limbs are bent. 
Advantageously, overlapping end portions of the flanged spacer strip 
material are brought together so that at each zone of overlap, a short 
retaining limb nests within the end of the other length of spacer strip 
material. 
The length of spacer strip material may be pre-cut to the desired size or 
sizes and fed, e.g. in pairs, to a frame forming mechanism, but it is 
preferred that lengths of spacer strip material each be fed from a 
continuous stock and cut to length prior to bending. 
Preferably, the spacer strip material is fed between rollers arranged to 
profile the strip lengths to define a web and at least one flange portion. 
In the most preferred embodiments of the invention, there are two lengths 
of spacer strip material and these are supplied in parallel, are cut to 
length, and are bent and joined to form a rectangular spacer frame. 
The present invention extends to a glazing panel, for example a hollow 
glazing panel, which has been manufactured by a method as defined above. 
After completion of the frame, it may be removed for storage and subsequent 
incorporation into a panel, but it is preferably transferred directly to 
one sheet of the panel preparatory to positioning of the other sheet of 
the pair in contact with the frame. 
This feature of the first aspect of the invention is considered to be of 
particular importance because of the way in which it simplifies the 
transfer of a preformed spacer frame to a sheet for incorporation into a 
hollow panel. 
Indeed, this feature of the first aspect of the invention is not limited to 
any particular method of preforming such a spacer frame, and accordingly, 
in its second aspect, as broadly defined, the present invention provides a 
method of manufacturing a glazing panel comprising a pair of glazing 
sheets separated by an intervening marginal spacer frame in which a frame 
is formed of strip material and is marginally secured between the pair of 
sheets. The frame is formed from the strip material by bending it and 
joining its ends together and the thus formed frame is transferred 
directly to one of the sheets preparatory to positioning of the other 
sheet of the pair in contact with the frame. 
Preferably the frame is transferred by vertical movement to a sheet located 
beneath a station in which the frame is formed and advantageously opposed 
end portions of the strip material are bent relative to an intervening 
portion which will constitute one side of the frame and which is moved 
parallel with itself during the transfer. 
In the most preferred embodiments of the second aspect of the invention, 
the frame is formed by a method according to the first aspect of the 
invention. 
The present inventionn is primarily concerned with the manufacture of 
glazing panels comprising a pair of vitreous sheets separated by an 
intervening marginal spacer frame formed of a metallic strip material, and 
in such cases it is preferred that the panel should be bonded together by 
soldering the spacer frame to metallised margins of the sheets. 
The invention includes apparatus for performing the method according to the 
first aspect of the invention, and accordingly provides apparatus for use 
in manufacturing a glazing panel comprising a pair of glazing sheets 
separated by an intervening marginal spacer frame formed to a required 
size and shape from strip material and marginally secured between the pair 
of sheets. The apparatus comprises a frame forming mechanism which 
includes guide means defining at least two paths for feeding required 
lengths of the strip material, stop means defining a position for the 
leading ends of such strip material as it is fed, a plurality of bending 
stations arranged to bend such strip material on at least one path to form 
frame corner angles at required distances from the stop means, and means 
for joining the ends of spacer strip material which has been fed along 
said paths and bent, thereby to form the frame. 
The invention provides apparatus for mechanically forming a spacer frame 
for incorporation into a hollow panel and thus reduces the requirement for 
highly skilled labour while at the same time permitting the uniform 
production of such frames. 
Preferably, at least one bending station comprises a backing support 
abutment and a strip bending member mounted for movement relative to said 
abutment for progressively wiping or rolling the strip about the abutment. 
Advantageously, the abutment and bending member at each such bending 
station are relatively retractable, so that spacer strip material of 
channel form can easily be released from such station after bending. 
Preferably, the abutment and bending member are shaped to support the 
flange(s) of flanged spacer strip material at the bending zone during 
bending. This can readily be arranged by using an abutment which defines a 
channel portion for receiving the flanged spacer strip material and 
mounting the bending member so that it can enter such channel to support 
the flange(s) of spacer strip material located therein, as is preferred. 
Advantageously, the abutment and bending member are shaped and arranged to 
deform the web of flanged spacer strip material at the bending zone to 
relieve bending stresses in the flange(s). 
Preferably, the abutment and bending member have complementary 
cross-sections. 
The bending station, stop means and paths may be relatively spaced so that 
the ends of strip material fed along the paths can be brought together in 
overlapping relationship by the bending operation alone. For the 
production of a series of frames of the same dimensions, such bending 
stations, stop means and paths may be at fixed locations. 
In order to facilitate the production of spacer frames of different 
dimensions on a single apparatus, it is preferred that means be provided 
for relatively displacing at least one bending station and/or stop means 
and/or path so that the ends of strip material fed along said paths can be 
brought together in overlapping relationship by the bending operation. 
Advantageously, the joining means comprises at least one crimping mechanism 
for joining overlapping ends of the spacer strip material. 
Preferably, a channel support member is provided for supporting each pair 
of overlapping ends of the spacer strip material, and the crimping 
mechanism comprises a pair of crimping jaws shaped to enter the channel of 
such support member and engage the side walls of such channel so that on 
such entry they are progressively closed by cam action. 
Advantageously, the apparatus has two parallel feed paths for the spacer 
strip material, and preferably there are two bending stations located on 
each such path. 
Preferably, means are provided for feeding said spacer strip material along 
each path from a continuous stock, and stop means and spacer strip cutting 
means are located on each path. 
Advantageously, upstream of such cutting means there is provided, on each 
path, profiling means (e.g. rollers) for folding flat strip material into 
channel form as it feeds from its stock along its path. 
Advantageously, cutting means on one path are associated with a mechanism 
for narrowing the web of the trailing end of the cut length of spacer 
strip material and the web of the leading end of the continuous stock. 
In preferred embodiments of the invention, on one path, the stop means are 
located a fixed distance downstream (in relation to the direction of a 
strip feed) of the downstream bending station and the cutting means are 
located a fixed distance upstream of the upstream bending station, and 
preferably in each case the distance is such that strip material fed along 
the path to the stop means and cut to length and bent will have end limb 
portions between 2 and 15 cm long measured from each end to the apex of 
the closer bend. 
Preferably, there is one fixed and one movable bending station on each 
path. This allows the manufacture of frames of different lengths. 
Advantageously, the guide means are movable to cause relative approach or 
separation of the paths, and the stop means and cutting means are movable 
along one of the paths. This allows the manufacture of frames of different 
widths. 
The invention includes a plant for the manufacture of glazing panels 
comprising a pair of glazing sheets separated by an intervening marginal 
spacer frame formed to a required size and shape from strip material and 
marginally secured between the pair of sheets. This plant includes a 
conveyor for conveying glazing sheets, a mechanism for forming a frame 
above the conveyor and means for effecting release of the frame onto an 
underlying glazing sheet on the conveyor. 
Preferably, the plant includes a second conveyor for conveying sheets and 
means for transferring sheets from the second conveyor onto a spacer frame 
on a sheet carried by the first conveyor.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In FIG. 1 sheets, e.g. of glass (not shown) are brought along a feed 
conveyor 1 whence they are transferred to two parallel conveyors 2, 3 of a 
panel assembly line. A stockpile 4 may be built up at the start of these 
parallel conveyors 2, 3. These conveyors are indicated as being divided 
into various zones where different operations may be performed. On the 
conveyor line 2, sheets pass through a first zone 5 where their position 
and size can be checked. They are then fed to a zone 6 located beneath a 
frame forming apparatus 7 constructed in accordance with the invention. 
After a spacer frame has been formed there and deposited on an underlying 
sheet, the sheet and frame pass to a zone 8 where the positioning of the 
frame can be adjusted. A second sheet meanwhile has been conveyed along 
the second of the parallel conveyors 3. 
When these two sheets reach a zone 9, the second sheet is transferred onto 
the frame lying on the first sheet, and the assembly continues along the 
conveyor line 2 to a bonding zone 10 and from there to an exit conveyor 
11. 
FIG. 2 shows the frame forming apparatus 7 in greater detail. 
The mechanism comprises a pair of parallel guide rails 12, 13 of which one 
12 is fixed while the other 13 is movable parallel with itself towards or 
away from the first. Each guide rail 12, 13 carries a reel 14 of flat 
spacer strip material, e.g. of copper coated with tin and/or solder alloy 
from which the spacer strip material 15 is delivered to a series of 
profiling rollers 16 arranged to fold the spacer strip material 15 into 
channel form. 
The fixed rail 12 carries a first bending station 17 at a fixed position 
along its length. Downstream of the first bending station 17, there is 
located a second bending station 18 which is adjustable in position along 
the rail 12, and downstream of that is located an end stop 19 adjustable 
in position along the rail 12 with respect to each of the bending stations 
17, 18. A cutter 20, also adjustable along the rail 12 is located upstream 
of the first bending station 17 for cutting the spacer strip material 15 
to length. 
The movable guide rail 13 carries a fixed bending station 21 located 
opposite the fixed bending station 17 on the fixed rail 12, and a movable 
downstream bending station 22. A cutter 23 is located a short fixed 
distance upstream of the fixed bending station 21, and an end stop 24 is 
ganged for movement with the movable bending station 22. 
After the size of the sheet for which a frame is required has been checked, 
the movable bending stations 18, 22 are positioned as necessary with 
respect to the fixed bending stations 17, 21 to ensure that the frame will 
be of the correct length; the guide rail 13 is moved as necessary relative 
to the fixed guide rail 12 to ensure that the frame will be of the correct 
width, and the cutter 20 and end stop 19 are positioned along the fixed 
guide rail 12 to ensure that the correct length of spacer strip 15 is 
drawn off. 
When the spacer strip material 15 has been fed to the end stop 19 and cut 
to length, its free ends 25, 26 are bent following arcs 27, 28 to their 
positions shown in full lines. After this, the free ends 29, 30 of the 
spacer strip material fed along the movable rail 13 to the end stop 24 and 
cut to length are also bent around as shown so that they overlap and nest 
within the free ends 25, 26 of the other length of strip material 15 at 
overlap zones 31, 32. 
It will be noted that because the end stop 24 is ganged to the movable 
bending station 22 and because the cutter 23 is a fixed distance upstream 
of the fixed upstream bending station 21, the free ends 29, 30 of the 
spacer strip material fed along the movable guide rail 13 will when bent 
always lie in zones 31, 32 (the overlap zones) which are fixed in relation 
to their associated bending station 22, 21 respectively. Crimping means 
(not shown) are provided at each overlap zone. 
Also shown in FIG. 2 is an optional device 33 having a pair of points 34 
for puncturing the spacer strip material. The punctures (not shown) permit 
pressure equalisation between the interior and exterior of the glazing 
panel to be manufactured, and also permit the interior of the panel to be 
flushed with dry air or some other gas mixture. The punctures also provide 
paths through which the panel interior may be evacuated. After 
conditioning of the interior atmosphere of the panel, the punctures may be 
sealed, e.g. with solder. 
FIGS. 3 and 4 are respectively plan and sectional views of bending stations 
such as 17 and 22. The bending stations 18 and 21 would be constructed as 
mirror images of these bending stations. The bending station shown 
comprises a support plate 35 to which is fixed a block 36 defining a track 
37 for a backing support tool 38 shown in greater detail in FIG. 5. As 
shown in FIG. 5, the head of the backing support tool 38 is in the form of 
a channel 39 which has a protuberance 40 in its base for deforming the web 
of a length of spacer strip at the apex of the bend during the bending 
process. To assist in this, the tool 38 is provided with an oblique 
channel 41 in which runs a wedging member 42 (FIG. 3) operable by a ram 43 
to thrust the backing support tool 38 into the apex of the bend. The side 
walls of the channel 39 serve to support the flanges if any of a length of 
spacer strip material against splaying during bending. 
The block 36 has along the lower edge of one side thereof an L-shaped 
recess 44 into which a length of spacer strip material can be fed prior to 
bending, and on an adjacent side, a similar L-shaped recess 45 into which 
the free end of the strip material can be bent. The block 36 and backing 
support tool 38 thus together act as a former around which the spacer can 
be bent. 
The support plate 35 also carries a slide 46 operable by a ram 47 to clamp 
a length of spacer strip material in the recess 44 of the backing block 
36. In particular, the slide carries a spring loaded clamping member 48 
shaped to enter a channel form spacer strip 15 and clamp it in the recess 
44 close to the apex of the bend to be formed. 
The slide 46 carries a bending ram 49 attached to a rack 50 which engages a 
pinion 51 mounted for rotation on an axle 52 concentric with the centre of 
curvature of the bend to be imparted to the spacer material. 
The pinion 51 has fixed thereto a bending tool 53 shaped to nest inside a 
channel form spacer member so as to support its flanges against inward 
folding, and having an edge face complementary in shape to the head of the 
backing support tool 38 (see also FIG. 5). 
As the bending ram 49 draws out the rack 50, the pinion 51 is rotated so 
that the bending tool 53 rolls the spacer strip material 15 around the 
backing support constituted by the recesses 44, 45 of the block 36 and by 
the tool 38. If desired the recesses 44, 45 may be so aligned that the 
spacer strip is bent through slightly more than the required angle, say 
1.degree. to 2.degree. more, to allow for elastic recovery. 
After bending, the overlapping ends of the spacer strip in the overlap 
zones 31, 32 (FIG. 2) are crimped together by an apparatus such as will be 
described with reference to FIG. 6, and when the ends have been crimped 
together, the clamping ram 47 is operated to withdraw the slide 46 and the 
members 48 to 53 carried thereby and the support tool 38 is also withdrawn 
so that the thus formed spacer frame can drop onto an underlying glazing 
sheet. 
The crimping apparatus shown in FIG. 6 comprises a spacer guide block 54 
mounted to the support plate 35 of a bending station 21 or 22 on the 
movable guide rail 13 in the overlap zone 32 or 31 respectively. The guide 
block 54 comprises a channel 55 for receiving overlapping ends of the 
spacer strip material which is partially cut away in the plane of the 
figure to provide camming surfaces 56. Also mounted on the support plate 
35 is a crimping ram 57 whose piston rod is attached to an arm 58 carrying 
a slide 59 movable with respect to the support plate 35 and carrying 
crimping levers 60, 61 pivotally mounted to the slide at 62, 63. The 
crimping levers 60, 61 are biassed towards their open positions by spring 
plungers 64, 65. The front ends of the crimping levers are provided with 
camming surfaces 66, 67 so that as the crimping ram is operated to cause 
approach of the crimping levers 60, 61 to the spacer guide block 54, these 
camming surfaces 66, 67 engage the camming surfaces 56 of the guide block 
to cause the levers to close and thus crimp together the flanges of 
overlapping ends of channel form spacer strip material caught between the 
crimping heads 68, 69 provided on the levers. As an alternative, or in 
addition to the slide 59 being movable, the guide block 54 itself may be 
movable. 
FIGS. 7 and 8 show an apparatus for cutting channel form spacer material to 
length while at the same time narrowing the channel at the cut ends so 
that such ends can nest inside overlapping non-narrowed channel ends. 
Channel form spacer strip material 15 is fed along a channel 70 in a block 
71 fixed to a supporting frame 72. The strip 15 is held in place by guides 
73. A movable support 74 is attached to four guide bolts 75, each 
surrounded by a spring 76, and the bolts and springs lead through holes in 
a block 77 fixed to the frame 72. The guides 73 are fixed in the block 77 
and the movable support 74 is slidable along them. A slide 78 is carried 
by the bolts 75 and is thrust against the bolt heads by the springs 76. A 
stop block 79 limits rearward travel of the slide 78. A shearing punch 80 
leads through passages in the movable support 74, block 77, slide 78 and 
stop block 79, and is fixed with respect to the slide 78 by a pin 81. The 
passage through the movable support 74 is indicated at 82. To either side 
of this passage 82 there is a rectangular projection 83 on the movable 
support 74 which is of a size to fill the channel form strip 15 and clamp 
it in the channel 70 of the block 71. For a short distance immediately to 
either side of the passage 82, this projection is of reduced dimensions as 
shown at 84. 
Carried by the fixed block 71, in register with the reduced portion 84 of 
the projection 83 is a swaging die 85 which is slidable under the control 
of a ram operable wedge member 86. The die 85 has a through passage 87 to 
allow sheared portions of spacer strip material to be thrust therethrough 
when the device is operated. 
In operation, when the desired cutting point on the spacer strip material 
15 is opposite the shearing punch, this is thrust forward by a ram (not 
shown). The punch 80 carries with it the slide 78, and this in turn via 
the springs 76 pushes forward the movable support 74 until the strip 
material 15 is clamped firmly in the channel 70 by the projections 83. 
Further movement of the shearing punch 80 compresses the springs 76 and 
the punch then slides in the passage 82, until it punches out a portion of 
the strip material 15 and pushes it into the swaging die passage 87. The 
swaging die 85 then advances on the spacer strip from the opposite 
direction and swages its flanges down on the reduced portions 84 of the 
rectangular projection 83, on both sides of the cut, so that the web of 
the end portions of the strip material are narrowed and the end portions 
can nest inside an overlapping end of another length of channel spacer 
strip material on formation of the frame. 
The cutting device illustrated in FIGS. 7 and 8 is designed to constitute 
the cutter 23 (FIG. 2) on the movable guide rail 13. 
The other cutter, shown at 20 in FIG. 2, may be made in substantially 
similar manner except that there is no requirement for a swaging die such 
as 85 nor is there any requirement for the clamping projections 83 to have 
portions such as 84 of reduced height.