Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
The present invention relates to improvements in
expander machines for forming open-mesh expanded material from
webs which have beforehand been slit on a rotary slitting
machine so as to provide them with an array of parallel
discontinuous slit lines. More especially, the machine is
intended for production of expanded aluminium meshes for use
as anti-explosive fillings such as are described in British
patent no. 1,131,687 dated October 18, 1966, in the name of
Joseph Szego, although it may be employed in the production of
other kinds of expanded materials.
A known form of expander machine for expanding rotary
slit webs comprises a pair of expander arms with vertically
and horizontally diverging edges along which the slit web is
passed, the web slipping laterally over the diverging edges and
being spread therebetween so as to open the slits in the web
out into diamond-shaped meshes. The known form of machine is,
however, subject to numerous disadvantages which we have now
overcome and these are described in greater detail hereinafter.
In one aspect of the invention, we support the expander
arms of an expander machine by mounting them on a sub-frame
through adjustable connections allowing the angle between the
edges of the arms ~o be widened or diminished, and ~he sub-frame
is mounted on a main frame through further adjustable connections
allowing the sub-frame to be tilted about a pivotal axis
extending longitudinally of the direction of web fed on the
expander arms. This allows the angle between the expander arms
to be adjusted to varying angles of inclination as may be
necessary to obtain expanded mesh~s of a desired mesh
configuration, while allowing the expanded output web from the
machine to be supplied in a horizontal plane by tilting the
main frame of the machine as appropriate to one side or the
other. For the purposes described in the above-mentioned patent,
the expanded product may be laid in superimposed, contiguous
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layers to form a bale of metal mesh, and this operation,
whether carried out by reeling the product up, folding it, or
stacking separate sheets cut from the web, can most conveniently
be carried out with the web being delivered in a horizontal
plane. Further, if the output web of expanded product is
inclined, it may tend to pull to one side or deform under the
force of gravity, resulting in a bale of ill-defined shape and
undesirably irregular density. By delivering the expanded web
directly horizontally from the expander machine, the need for
guides to restore the web to the horizontal is avoided, and
this is particularly important where thin metal foils are used
and the expanded webs are relatively frail and vulnerable to
deformation.
Preferably, the tilting axis of the machine sub-frame
extends centrally off the web feed on the expander arms, so that
the line of travel of the output of expanded material does not
shift when the sub-frame axis is tilted.
According to a fur~her aspect of the present invention,
we provide an expander machine with grippers for retaining and
~0 conveying the edges of the web in its travel along the expander
arms, these grippers comprising a driven endless belt having a
longitudinal groove and a driven endless blade member parallel
to and pressing edgewise into the groove, the web edges being
gripped in the said groove between the belt and the blade member~
We have found that these gripper devices efficiently and
reliably retain the edges of the we~, and are particularly useful
when expa~ding metal webs in the form of thin foils such as the
foils of five to twelve thousandths of an inch thickness that
we describe in our above-mentioned patent applicationO Whereas
in the known expander machines the edges of the webs are
typically retained by sets of driven gripping rollers arrayed
along the length of the expander arms, we have ound that these
roller arrangements do not adequately support and ~etain the
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edges of thin foils, since inevitably there are gaps between
the rollers and loss of gripping, deformation and tearing of
the foil may occur at unsupported points. With our arrangement,
the foil may be supported firmly and uniformly a]ong the entire
extent of its travel over the expander arms.
In a further aspect of the present invention, an
expander machine includes supporting structuxe for rotatably
mounting a coil of slit metal web material, and guide members
are arranged between the coil supporting structure and the
expander arms which feed the slit web directly to the arms.
When expanding thin metal foils, we have found that the
throughput speeds of the expander machines are necessarily
limited because the relatively weak foils cannot withstand the
stresses which are generated in high speed operation. The foils
can, however, be slit at a much higher rate, and we have found
that typically the foils may be slit at a throughput speed
approximately three times the maximum expander speed. After
slitting the foils, we therefore prefer to reel them up into
slit coil stock and use the coil stock produced from a lesser
number of slitter machines as the feed supply for a greater
number of expander machines, thus increasing overall production
rates.
Preferably, a guide for the web ~eed to the expander
arms is in the form of a smooth bar non-rotatably supported
between the coil-supporting structure and the expander arms,
the web slipping around the bar, and the bar being inclinsd non-
perp~ndicularly to the direction of web feed along the expander
arms.
Preferably the axis of the bar is parallel to or
aligned wi~h the general plane of the web at its region of
approach to the expander arms.
Where the ~xpander arms are arranged so as to be
adjustable in their angle of divergence and to be tiltable as a
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37
whole so as to maintain the output expanded web horizontal,
this guide arrangement for the web feed avoids the need to tilt
the input supply of slit web when the expander arms are tilted.
Further, where the expander machine is fed from a coil of slit
metal web, it avoids the need to move the heavy coil stock
upwards and downwards against the force of gravity when the
expander arms are tilted.
In another aspect of the present invention, we
provide an expander machine with expander ~rms in the form of
members demountably secured on respective support arms, the
support arms being connected to the machine frame by means
allowing them to be laterally adjusted towards or away from one
another. This allows the machine to be adjusted to accommodate
input webs of varying width. When ad~ustments are made in the
spaci~g between the support arms, a replacement set of expander
arm members can be substituted in the machine, to provide for
satisfactory support of the web material at the entrance end of
the expander arms.
With this arrangement, it is preferred to convey th~
metal web along the expander arms using an endless belt in
gripping contact with the edges of the web. When a fresh set
of expander arms are substituted in the machine, adjustment in
the length of the gripping run of the belt which is necessary to
insure that the web is released once it has been expanded to the
desired extent can readily be achieved by adjusting the positions
of pulleys around which the belt runs, or i~ necessary by
substituting a belt of a different length, and the b~lt may
conveniently be driven by transversely extending drive shafts
which can readily be arranged so as to be adjustable laterally
together with the support arms for the expander arms. This
provides for a relatively simple adjustment procedure for
setting up the machine to accommodate webs of differing widths.
In one preferred embodiment, which is especially
~7~
adapted for expanded material of varying width, the surface of
each expander arm on which the web is to be supported and over
which the web slips as it moves through the machine, is made
smooth-surfaced at least in a region extending forwardly from
the rear of the arm and over a major part of its length, and
the web is conveyed by being gripped at each edge between the
smooth surface of the expander arm and a driven endless belt
which runs along the expander arm and is pressed towards the
said smooth surface.
We have found that this gripping arrangement efficiently
and reliably retains the edges of the web, and is particularly
useful when expanding metal webs in the form of thin ~oils such
as the foils of five to twelve thousandths of an inch thickness
that we describe in our above-mentioned patent application.
Moreover, the belts can accommodate metal webs of varying widths.
Expander machines embodying the various aspects of the
present invention will now be more fully described, by way of
example only, with reference to the accompanying drawings in
which:
Figure 1 shows a perspective view of a first embodiment
of an expander machine;
Figure 2 shows a side view of the coil stock holder of
the machine viewed on the arrow A in Figure l;
Figure 3 shows the mechanical drive mechanism of the
machine;
Figure 4 shows a side ~iew of one expander arm of the
machine taken on the line 4-4 of Figure l;
Figure 5 shows a cross-section through the expandér
arms taken on the line 5-5 of Figure 1;
~igure 6 shows a detail of a belt of the web-conveying
arrangement;
Figure 7 is a vertical section ~hrough the main frame
and sub-frame of $he machine taken on the line 7-7 of Figure l;
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17
Figure 8, which appears on the same sheet as Figure 3,
shows in detail the slippage of slit foil over the inclined
edge of the expander arms in the region encircled at 8 in
Figure l;
Figure 9 shows a transverse partial section through
the support structure for the expander arms on the line 9-9 of
Figure l;
Figure 10 shows a vertical section through the expander
arm supports taken on the line 10-10 of Figure 9;
Figure 11 shows a perspective view of an expander
machine according to a second emhodiment;
Figure 12 shows in more detail the drive mechanism for
the web-conveying endless belts of the machine of Figure 11;
Figure 13 shows a cross-section through the expander
arms taken on the line 13-13 of Figure 11;
Figure 14 shows a suppoxt for the endless ~elt at the
output end of the expander arm, partly in section on the line
14-14 of Figure 11;
Figure 15 shows in plan an adjustment for the expander
arms;
Figure 15a shows a transverse section on the line
15a-15a of Figure 15;
Figure 16 is a fragmentary view of the expander arm;
Figure 17 shows the support arrangement for the endless
belts and the expander arms at the input side of the machine,
partly in section on the line 17-17 of Figure l;
Figure 18 is a view similar to Figure 17 showing the
outer side of the upper expander arm on the line 18-18 of '
Figure l; and
Figure 19 shows a view from the rear of the expander
arms along the line 19-19 of Figure 11.
Referring to the drawings, wherein like reference
numerals indicate like parts, the machines comprise a main
~ 7 ~
8~
frame 20, and a sub-frame 21 pivoting on the main frame about
horizontal axis 2~. At one end, the frame 20 carries an upright
23 in which horizontal shaft 24 of the sub-frame pivots freely
within a bearing 26. At this end, the sub-frame 21 is defined by
a plate 27 to which shaft 24 is connected.
The opposite end of the sub-frame is constituted by a
generally D-shaped mounting portion 28 (also shown in Figure 7)
connected to the end plate 27 by a pair of vertically spaced
horizontal tie rods 29.
The mounting portion 28 of the sub frame is supported
at one side on a vertical extension 31 of the main frame 20 by a
locking bolt 32 for clamping the mounting portion 28 to a
projection 33 of extension 31. The locking bolt 32 enters an
arcuate slot 34 in the projection 33.
At its lower end, the mounting portion 28 has an
arcuate raised key 36 sliding in a curved key way channel 37
secured on the main frame 20. The centre of curvature of the key
way channel 37 and of the slot 34 is arranged coaxial with shaft
24, so that the whole sub-frame 21 may he rotated about this axis.
For tilting the sub-frame about this horizontal axis,
a hand wheel 38 is provided on a threaded shaft 39 engaging a
threaded sleeve coupled to portion 28 through a pivotal coupling
42.
A holder for a coil of slit metal stock has side plates
43, and front and rear tie bars 44 and 46 of which the front bar
44 slides at its ends in bearings 47 on the main ~rame 20. The
rear bar 46 has a key block 48 sliding in a horizontal channel key
guide way 49 connected on the frame 20, 50 that the whole hoider
may be shifted laterally. Blocks 51 are connected on the side
3Q plates 43, carrying bearings 52 through which passes a shaft 53
around which the coil stock is wound. The blocks 51 have hinged
sections 54 releasably held in place by clamping screws 56 allowing
the shaft 53 to be lifted from the machine when fresh coil stock
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is to be placed in the holder.
For keeping the feed of the slit web stock 58 in
proper alignment, a pair of edge detectors 59 are mounted on
frame 20 ad~acent the feed of the web. These control the
operation of an hydraulic cylinder 60 connected between frame 20
and one side plate 43 of the holder and shift the holder
laterally in response to signals from the edge detectors 59, so
that the slit metal web 58 is maintained in alignment with the
horizontal axis of sub-frame 21.
The shaft 53 of the coil stock holder is provided
with a brake to keep tension in the web and to prevent over~
feeding. A brake drum 66 on one side plate 43 has a friction
band 67 passing over it and is fixed at one end to the plate 43.
The other end of the band 67 carries a weight 68 holding it in
frictional engagement with the drum 66. The drum 66 connects to
the shaft 53 through a shaft 64, a gear 63, and an upper gear 62.
The plates 43 also carry posts 69 which support a
roller 71 over which the web passes towards the sub-frame 21.
The form of coil stock holder employed is separable as
a distinct unit from the remainder of the machine. This
facilitates the change-over procedure if fresh coil stock is to be
substituted and may enable the coil stock holder to be employed
for reeling up slit foil supplied from a metal slitting machine.
In Figure 1, the main frame 20 is divided in two halves 20a and
20b separable along a joint 72. A latch 73 serves to retain the
frame parts releasably togetherO
From the holdex, the web 58 passes beneath a roller 74
journalled at on~ end in a bearing 76 on end plate 27 and at the
other end is an extension of the D-shaped mounting portion 28.
The web 58 then passes to a smooth circular section bar 77 non-
rotatably secured to end supports 78 connected on the tie rods 29.
The axis of the bar 77 is parallel to the plane of the w~b at a
region 79 where it subsequently approaches a pair of diverging
expander arms 81 and 82. The upper surface of the bar 77 is
_. g _
aligned with the rear end edges of the arms 81 and 82 and its
axis is inclined with respect to the direction of travel of the
web along the expander arms 81 and 82, so as to redirect the web
from its initial direction of lateral feed from the coil stock
holder, to the arms 81 and 82~ In the present instance, where
the coil stock holder and the expander arms 81 and 82 are
arranged perpendicular to one another~ the axis of the bar 77 is
inclined at 45 to the final direction of ~ravel along the arms
81 and 82.
We have found that if a roller is used instead of the
non-rotatable bar 77, the web tends to creep upwardly along the
roller, resulting in misaligned delivery of the web.
In the embodiment illustrated in Figures 1 to 10, a
pair of spaced parallel outer side plates 83 connected by a cross
brace 84 are fixed on mounting portion 28. On the inner sides of
plates 83 are connected a pair of housings 86 supporting driven
rubber-surfaced rollers 87 through the nip of which the web 58 is
drawn.
Forwardly of the rollers 87, upper and lower transversely
extending shafts 88 extend between and are connected to the plates
83. As shown in Figures 4, 9, and 10, these shafts 88 slidingly
support a pair of inner plates 89 which have bushings 91 through
which the shafts 88 pass. The plates can be fixed at any desired
spacing apart by s~t screws 92 engaging on flats 93 on the
surfaces of the shafts 88.
These slidable inner plates 8~ support the expander
arms 81 and 82, so that the lateral spacing of the expander arms
can be adjusted. For controlling this adjustment, bolts 94 are
provided which extend inwardly from the outer plates 83 and are
threaded at their ends 95 in holes in the inner plat~s 89. The
outer ends of the bolts 94 are retained against axial mo~ement in
the outer plates 83 by collars 95 fixed on the bolts 94 and
engaging on the plates 83.
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Support arms 101, which carry the expander arms 81 and
82, are connected pivo~ally on the inner sides of the plates 89.
As shown in Figures 4 and 9, a bolt 102 passes through each of the
side plates 89 and through the outer wall of the support arm 101.
The outer end of the bolt 102 carries a nut 103, and the inner end
of each bolt 102 carries a disc 104 which fixed to the outer wall
of the support arm 101 through a pin 106 passing through the outer
wall of the arm 101. When the nut 103 is loosened, the support
arms 101 together with the expander arms 81 and 82 can be tilted
upwardly and downwardly about the axes of the bolts 102.
Forwardly of the bolt 102, each inner plates 89 has an
arcuate slot 107 through which the support arm is further connected
to the plate 89 by a clamping bolt 108 which has to be loosened
be~ore making pivotal adjustment of the support arms 101 and the
expander arms 81 and 82. A calibrated scale may be provided along
the slot 107 to indicate the angle of the arm 81 or 82.
As shown in Figures 5 and 9, the expander arms 81 and
82 are secured along their outer edges, for example by welding, to
supporting strips 109 connected by bolts 110 to strips 111 bolted
to the outer sides of the support arms 101.
The expander arms 82 are in the form of generally
triangular flat plates and have mutually oppositely directed lip
flanges 112 and 113, respectively, along their diverging inner
edges. The rear edges of the expander arms 81 and 82 are parallel
and slightly offset, one above the other. Relative to the plane
of the web 58 and the region 79 where it approaches the expander
arms 81 and 82, the left hand arm 81 is inclined upwardly in the
longitudinal direction of travel of the web, while the right'hand
arm 82 is inclined downwardly. The expander arms 81 and 82 are
also inclined to the horizontal in the transverse direction.
The flat plates which constitute the expander arms 81
and 82 lie perpendicularly to the planes through which their
respective support arms 101 pivot about the pivotal support bolts
-- 11 --
~lO9~B7
-
102. Thus, with -the expander arms 81 and 82 inclined upwardly
and downwardly with respect to the ini~ial plane of the input web
at thè point where it enters the expander arms, the inner edges
of the expander arms 81 an~ 82 diverge, from a point where the
inner edges coincide one above the other, in both the transverse
and longitudinal directions in the direction from the entrance
ends of the expander arms to their exit ends.
Each of the expander arms 81 and 82 is provided with
gripper devices for retaining and conveying the edges of the web
in its travel along the expander arms. In the embodiment of
Figures 1 to 10, the gripper device comprises grooved endless
belts 11~ and 116, and blade-like endless belts 117 and 118 which
co-operate with the grooved belts.
As shown in Figure 6, the belt 114 comprises an
assembly of plate-like metal links 119 e.g. of steel, having
toothed projections 121 which engage with the drive sprockets for
the belt. Standard Morse silent chains may be employed as the
belts 114 and 116. A groove 122 is machined on the outer side of
each belt.
As best shown in Figure 5, the grooved belts 114 and
116 run adjacent the outer edges of the expander arms 81 and 82
and are located and guided by guide bars 123 having retaining lip
portions 1~4. The guide bars 123 are secured on the support arms
wire 1 by bolts 126.
As shown in Figure 3 and 4, the grooved belts 114 and
116 extend around sprockets 127 and 130 at the rear end of the
support arms 101, pass around an idler pulley 128 mounted at the
forward end of the support arms 101~ and over a tensioning idler
pulley 129 supported on a bracket 131 mid-way along the support
30 arm 101. The tensioning pulley 129 is movably supported in a
slot 132 in the bracket plate 131, so that the tension in the
grooved belts can be adjusted. The support arms 101 may be
provided with a plurality of s~ckets spaced longitudinally for
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~79~37
supporting the idler pulley 128 at various positions along the
arm 101. This allows ~he effective length of the gripping run
of the belts 114 and 116 to be adjusted, so that the point at
which the web loses gripping contac~ with ~he belts 114 and 116
can be adjusted, to allow webs of different widths to be expanded
on the machine. In the preferred form, the bracket 131
supporting the tensioning pulley 129 is detachably mounted on the
arm 101, so that a bracket of different arm length may be
substituted allowing the length of the effective gripping run of
the belts 114 and 116 to be changed considerably without needing
to substitute fresh belts of different lengths for the ~elts 114
and 116.
The endless blade-like belts 117 and 118 which
cooperate with the grooved belts 114 and 116 extend around drive
pulleys 132 and 133 connected on the rear ends of the suppo.rt
arms 101, and pass around respective tensioning pulleys 134 and
136 adjustably mounted in slots 137 at the forward end of the
support arms 101.
As can be seen in Figures 1, 4 and 5, the grooved belts
114 and 116 run perpen~icularly to the blade-like belts 117 and 118.
In operation, the web is fed forwardly from the rollers 87 and
its ed~es become gripped at the point where the sprockets 127 and
130 press the grooved belts 114 and 116 into contact with the
blade-like belts 117 and 118~ Adjacent the outer edges of the
plates 81 and 82, the blade-like belts 117 and 118 run in a
groove formed between the supporting strips 109 and the spacer
strips 11.
Referring now to Figure 3, the drive mechanism fox the
belts 114, 116, 117 and 118 is shown. A motor 138 drîves a
pulley 13~ through a gear box 141. A belt 142 transmits the drive
to a main drive pulley 143 which turns a spur gear 144 carri~d on
a shaft 146 extending transversely of the adjacent support arm
101 carrying the expander arm 81. The gear 144 meshes with a
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387
spur gear 147 driving a parallel shaft 148 which turns the sprocket
127, driving the grooved belt 114 through engagement with the teeth
121 on the inner side of the grooved belt 114. A bevel gear
14~ on the shaft 148 drives a perpendicular shaft 151 through a
bevel gear 152, and the shaft 151 turns a pulley 153 connected
through a belt 154 to the pulley 132 which drives the blade-like
belt 117.
The main drive pulley 143 connects co-axially with a
sprocket wheel 156 driving a chain 157 which turns a sprocket wheel
158 connected through a shaft 159 to one of the rubber covered
rollers 87 which feed the web 58 towards the expander ar~s 81 and
82. The rollers 87 are coupled together through inter-engaging
gears 161 and 162 at one end. A shaft 163 extending from one of
the rollers 87 at the other end drives a sprocket 164. This is
coupled through a chain 165, to a sprocket wheel 166 connected on
a shaft 167. The shaft 167 drives the grooved belt 116 and the
blade-like belt 118 through a mechanism generally similar to that
already described in connected with the belts 114 and 117,
including a transverse shaft 168 driven through spur gears 169 and
171, and a perpendicular shaft 171 driven through bevel gears 172
and 173.
It should be noted that the chain 157 which drives the
rubber covered feed rollers 87 additionally drives a sprocket
wheel 174 coupled to a power take-off shaft 176 through a shaft
177 and a pair of bevel gears 178. The power take-off shaft 176
may be used to drive apparatus which composes the output web of
expanded metal from the expander machine into a multiple layer
mass, or may serve to synchronize the operation of such apparatus
with the operation of the expander machine. Figures 9 and 10 show
in greater detail the arrangement of the drive mechanism for the
grooved belt 114 and the blade-like belt 117 on the side of the
expander machine carrying the expand~r axm 81. It will be seen
that ~he main drive pulley 183 together with the transverse drive
sha~t 146 is supported on bearings 179 connected on the outer side
37
plate 83. The drive shaft 148 is supported on bearings 181 and
132 secured to the support arm 101 which is connected to the
inner side plate 89.
In order to permit lateral adjustment of the position
of the side plate 8~, provision has to be made for adjustment of
the drive shaft 148 relative to the main drive pulley 143. This
is achieved by supporting the shaft 146 at one end in a bearing
183 connected through a bracket 184 to the inner side plate 89,
and having the shaft 146 slidingly adjustable within a cylindrical
sleeve 186 which is keyed to both the main drive pulley 183 and the
shaft 146 by a key member 187 secured internally to the main drive
pulley 143, passing through an axially-extending slot in the
sleeve 186, and engaging in an a~ial groove 188 in the shaft 146.
The shaft 146 is lightly retained by the bracket 184 by a C clip
189 holding the shaft 146 against the inner race of the bearing
183, the other side of the inner race engaging with an enlarged
diameter end portion 191 on the shaft 146. The outer race of the
bearing 183 is lightly pressed by a C clip 192 into a cup 193
connected to the bracket lS4.
As the shaft 146 slides relatively freely in the sleeve
186, it traverses laterally together with the bracket 184, the
side plate 89, and the shaft 148 when the position of the inner
side plate 89 is adjusted.
On the opposite side of the machine, similar allowance
has to be made for lateral adjustment of the spur gear 169 relative
to the sprocket wheel 166, and this is achieved by supporting the
shaft 167 in a bearing on the inner side plate 89 which is .
liyhtly resistant to axial movement of the shaft relati~e to the
plate 89, and having the shaft 167 keyed to the sprocket wheel 166
through an arrangement allowing free relative axial movement.
In operation, the pre-slit web 58 from the coil stock
57 is fed forwardly, through the nip of the driven feed rollers
87 to the entrancP zone between the upper expander arm 82 and the
. ~, ;.
7~7
lower expander arm 81, where its Pdges are gripped by the two
sets of bladP-like belts 117 and 118 and grooved belts 114 and
116, which draw the web forwardly along the exp~nder arms 81
and 82. The edge gripping action, wherein the metal web 58 is
pressed into the groove 122 of the bel~s 114 and 116 by the blade
belts 117 and 118, and is deformed, as shown in Figure 5. The
web is carried longitudinally over the upper surface of the left-
hand expander arm 81 and over the lower surface of the right-hand
expander arm 8~. With the left-hand expander arm 81 inclined
upwardly with respect to the initial plane of the web 58, and the
right-hand expander arm 82 inclined downwardly, the inner edges
of the expander arms 81 and 82 diverge bo~h in the lateral
direction and in the direction normal to the initial plane of the
web. As the web moves progressively forwardly, it slips laterally
over the inner edges of the expander arms.
Figure 8 shows the expansion of slit metal foil 58,
which has an array of parallel longitudinal slits 194 of uniform
length arranged in regularly spaced parallel longitudinal rows,
with the slits in adjacent rows being longitudinally staggered
20 with respect to one another. As a result of the divergence of
the expander arms 81 and 82, a lateral force of tension is
developed in the web 58 causing the slits 194 to open out into
diamond shaped meshes along the zones where the web 58 passes
over the edges oE the expander arms. In the regions of the web 58
remaining in contact with the flat surfaces of the expander arms
81 and 82, the web 58 is supported against deformation, and the
slits 194 thus remain unopened until the web 58 slips over the
edge of the expander arm.
In order to obtain uniformly sized and orientated
diamond shaped meshes, it is desirable to arrange the expander
arms 81 and 82 so that their inner edges are inclined with respect
to the slits 194 in the web so as to be parallel to the angle at
which latexally adjacent slits 194 are off-set. This orientation
517
. . ,
is shown in Figure 8.
The degree of lateral expansion of the web, i.e. the
increase in the width of the expanded web as compared with the
original web can be varied by swinging the expander arms 81 and
82 towards or away from one another about the axes of the bolts 102.
When adjustments are made in the angles of inclination
of the arms 81 and 82, by tilting the suppor~ arms 101 about the
axes of the bolts 102, the forward ends of the expander arms 81
and 82, where the output expanded web is released from gripping
engagement between the two sets of belts 114, 117 and 116, 118,
will swin~ about a tilted axis, so that one arm becomes raised
while the other lowers as the adjustment is made. Once the
adjustment is made, the sub-frame 21 of the machine can be tilted
about the axis 22 by turning the handwheel 38, thus restoring the
plane o~ the output expanded web to the horizontal.
The machine can be adjusted to accommodate webs of
differing widths by adjusting the positions of the inner side
plates 89, employing.the adjustment bolts 94 to move the plates
89 together with the support arms 101 and the two sets of gripping
belts 114, 117 and 116, 118, towards or away from one another. To
avoid overlap of the rear edges of the expander arms Bl and 82,
which would cause undue strain in the web, or to avoid a gap
occurring between the expander arms at the entrance end which
would leave the web unsupported and result in the unsupported
portion of the web opening out into randomly orientated meshes,
fresh set of expander arms may need to be substituted for the
expander arms 81 and ~2 when the lateral adjustment is made.
As explained above, it is desirable to maintain a
predetermined orientation betw~en the slit lines in the web and
the inner edges of the expander axms. Thus, where a web o~
different width but with the same size and configuxation of slit
lines is to be expanded, the expander arms which will be
substituted in the machine will be geometrically similar to the
original expander arms.
As will be noted from the preceding description, a fresh
set of expander arms can be relatively easily substituted in the
machine by unscrewing the bolts 110, removing the existing
expander arms 81 and 82, and inserting a fresh set of expander
arms equipped with their own supporting strips 109 which have sets
of holes for receiving the bolts 110.
When a fresh set of expander arms is fitted to the machine,
the length of the effective gripping run of the belts 114, 117 and
116, 118 needs to be altered so that the web is released from
grippiny engagement at the point where it leaves the forward end
of ~he expander arms. This adjustment is carried out by moving
the position of the forward idler pulleys 128 which carry the
grooved belts 116, the pulleys 128 heing moved to another o~ the
sockets provided ~or this purpose in the support arms 101. The
positions of the tensioning pulleys 129 are also adjusted, to
ensure that tension is maintained in the belts 114 and 116, and
if necessary the supporting brackets 131 for the pulleys 129 are
replaced with brackets of different lengths.
Re~erring now to the embodiment illustrated in Figures 11
to 19, in this embodiment the edges of the web, instead of being
gripped along a narrow deformation line (the line of the groove
122), are gripped at each edge between a smooth surface and a wide
belt. As the wide belt can accommodate some variation in the
width of the web, it is not required that the lateral spacing of
the expander arms should be adjustable. Thus in this embodiment,
~he mounting portion 28 of the sub-frame 21 has a pair of
supporting side plates 210 that are attached directly to the
mounting portion 28.
` Each plate 210 has a right-~ngled lower rear extension
221, through which the plates 210 are bolted on the mountin~
portion 28 wi~h ~olts 222. The plates 210 are braced on the outer
sides by triangular fillets 223. The upper parts of the plat~s 210
are connected by a cylindrical cross brace 224, and the lower
parts by a rectangular channel section cross brac0 226.
The upper of the two rubber-covered rollers 87 is
vertically slidably mounted on the plates 210, and a control bar
225 extending between the plates 210 serves to control upward
and downward shifting of the upper roller. The bar 225 is
rotatable mounted in each plate 210 and at each end carries an
eccentric pin connected to the mounting of the upper roller,
whereby when the bar 225 is rotated, the upper roller 87 can be
shifted upwardly so as to be separated from ~he lower roller to
facilitate threading the web 58 into the machine and can
~hereafter be closed up again to grip the web firmlyO An
operating handle 225a is connected on the bar 225 for rotating
the bar 225.
Forwardly of the rollers 87, the web 58 is supported
between and guided by a pair of guide plates 227 and 228, best
seen in Figure 17, which are aligned with the nip of-the rollers
87. For the sake of clarity of the drawing, the arrangement ~or
supporting the plates 227 and 228 is not shown in Figure 1. The
plate 227 is carried on a pair of spaced arms 229 connected to the
channel-section cross-brace 226. The plate 228 is carried on a
pair of transversely spaced arms 231 which are pivotally connected
to arms 232, allowing the plat~ 228 to be swung towards and away
from the plate 227. Each arm 232 is connected through a
rotatably adjustable mounting on the cylindrical cross brace 224.
The plate 228 is movable by hand towards and away from the plate
227 through operation of a spring-loaded toggle linkage, comprising
a bar 236 pivotally connected to the middle portion of the plate
228, and a bar 237 pivotally connected to the bar 236 at a knee
238 and itself pivotally mwunted on a split clamp 239 secured with
a clamping screw 234 on the cylindrical cross brace 224 between
the clamps 233. The two paxts of the toygle linkage 236 ~nd 237
are biased together by a tension spring 241, and are shi~table by
19
a hand lever 242 from the closed position shown in solid lines
to the open position shown in broken lines in which the plate
228 is swung open to allow the leading edge of the web 58 to be
fed into the machine.
As shown in Figure 17, the leading and trailing edges
of the guide plates 227 and 228 are rounded to avoid tearing of
the thin foils with which the machine is intended to be used.
On loosening the clamp 239, the position of the guide
plate 228 can be adjusted to align it parallel with the plate 227.
A pair of hollow rectangular section support arms 101,
which carry the expander arms 81 and 82, are supported on the
inner sides of the side plates 210 forwardly of the guide plates
227 and 228. As shown in Figures 17 and 18, each arm 101 is
supported on its p~ate 210 through two bolts 243 passing through
arcuate slots 244 in the outer wall of each support arm 101.
Each support arm 101 is pivotally connected to its
adjacent side plate 210 through a dowel pin 246, the position o~
which is shown in Figures 17, 18 and 19, located in a bore passing
perpendicularly through the side plate 89 and in a boxe passing
partly through the wall of the arm 101 and partly through a small
block 245 welded on the support arm 101. The arcuate slots 244
in the support arms 101 are concentric with the dowel pins 246, so
that when the bolts 243 are loosened the angle between the support
arms 101 can be adjusted by swinging them about the pivotal axis
provided by the dowel pins. The two dowel pins 246 are co-axial,
so that the support arms 101 together with the expander arms 81
and 82 pivot about a common axis.
As shown in Figure 11, each of thP expander arms 81 'and 82
is s~cured to the support arms 101 by a bolt 247 fitting in a
circular hole at the rear or entrance end of the expander arm, and
acting as a pivot point about which the expander arm can be
swung in its own plane, and a ~eries of bolts 248 passing through
short arcuate slots 249 concentric with the bolt 247, to allow
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~7~37
limited swinging adjustment of the expander arms 81 and 82
relative to their respective support arms 101 about the bolt 247.
A fine adjustment member is provided on each arm for controlling
this adjustment. The adjustment member, as shown in Figures 1
and 6, consists of a screw 251 passing through a bracket 252
connected on the arm 101. The screw 251 is retained against axial
movement by bosses 253 connected on the screw 251 and abutting on
opposite sides of the bracket 252. The screw 251 threads into a
dowel 254 freely turning in a block 256 fixed on the expander arm
82. Within ~he block 256 is a bore 257 which accommodates the
screw 251 with sufficient clearance to allow for the limited
swinging of the block 256 relative to the screw 251. A knurled
knob 255 is provided for turning the screw 251, so as to shift
the arm 81 transversely relative to the support arm 101.
The gripper device for retaining the edge of the web 58
and conveying it along the expander arm, comprises an endless
resilient belt 258 which runs along the expander arm adjacent the
outer margin thereof in contact with the surface of the arm 81 or
82 over which the web 58 travels.
Each belt 258 is supported at opposite ends of the
expander arm on pulleys 25~ and 261 which are mounted on the inner
~ides of the support arms 101. The pulley 259 at the rear end of
the expander arm is driven while the pulley 261 at the front end
is an idler pulley. The pulleys 259 and 261 and the inner surface
of the belts 258 have cooperating rib~ing to give a positive
engagement and positive drive to the belts. As shown in Figure 16,
the belts 258 may be of composite construction, consisting of an
inner ribbed wear resistant layer 262 and a thin outer facin~
layer 263 of a softer resilient material adhered thereto, e.g. of
neoprene rubber, which can better engage with the webs to be
expanded.
The run of the belts 258 which lies adjacent the
respectivP expander arms 81 and 82 is pressed towards the expander
- 21 -
arm for increased frictional engagement with the web 58 by a
series of pressure shoes 264. The shoes 264 are arranged along
the entire length of the belt with only small spacing between
the individual shoes, and each shoe consists of a flat metal plate
with gently upwardly curved ends 266 to avoid the edges of the
ribbing on the belt 258 catching on the end edges of the shoes.
Each shoe 264 is retained loosely on a central post
267 lying parallel with the general plane of the shoe and secured
at its outer end by connection to the inner side of the support
arm 101. At its inner end each post 267 receives a bolt 268
which retains a guide strip 269 extending along the inner edges
of the shoes 266 and partly overlapping and engaging against the
side edge of the belt 258 so as to guide the belt 258 and retain
it against transverse movement.
The post 267 has a narrow central portion 271, and a pair
of circumferential grooves 272 spaced on either side of the
portion 271. Each shoe has a guide block 273 secured centrally
thereto which is formed at its free end with a central slot 274
receiving the necked portion 271 in loosely rubbing engagement.
The sides of the guide block 273 are in rubbing engagement with
the end shoulders of the necked portion 271. A split pin 276 may
be passed through the free end of the guide block 273, so that the
guide block 273 together with th~ shoe 266 is loosely retained on
the post 267.
Each groove 272 in the post 267 receives a bight portion
of a sti~f wire spring 277~ the ends of which press the shoe 266
towards the expander arm 81 so as to exert spring pressllre on the
belt 258 to grip and retain the edge of the web 58 against the
expander arm 81.
In order to provide a tensioning adjustment Eor the belts
258, each idler pulley 261 has a longitudinally adjustable support,
shown in Figure 14. The support arm 101 is formed with slots 278
and 279 in its inner and outer sides which accommodate a
22 -
37
, ~
cylindrical mounting member 281 receiving the axle of the pulley
261. At the inner side the mounting member 281 has spaced
shoulder plates 282 and 283 which bear slidingly on the edges of
the slot 278 in the support arm 101. Longitudinal adjustment of
the position of the mounting member 281 together with the pulley
261 is effected by an adjusting bolt 284 whose head engages on
the end wall 286 of the support arm 101 and whose threaded shank
engages in a threaded bore 287 in the mounting member 281.
An angled-section cover 288 or guard is provided over
the belt 258 and pressure shoe arrangement and is screwed to the
support arm 101 with screws 289.
The surfaces of the arms 81 and 82 over which the web
58 travels i.e. the upper surface of the left-hand arm 81 and
the lower surface of the arm 82, are made smooth surfaced at least
along a major part of their length extending forwardly from the
rear or entrance ends of the arms. These surfaces may be polished
and may have a polished chromium-plated surface. Alternatively,
the surfaces may have a low-friction coating e.g. a low~friction
plastics coating such as a TEFLON coating, so that the web to be
expanded will glide smoothly over the arms 81 and 82. It has
been found that with this axrangement tearing, deformation or wear
of thin foils to be expanded is reduced, while satisfactory grip
on and retention of the edges of the web can be obtained, at
least where the full width of the belts 258 is applied on ~he
expander arm surface. Howeverl as can best been seen from Figure
11, at the forward end of the expander arms 81 and 82 the belts 258
extend beyond the inclining inner edges of the arms 81 and 82,
and at this region the width of foil 58 gripped between the helt
258 and the arm 81 ar 82 is somewhat smaller. To avoid premature
release of the edges of the foil, the expander arms 81 and 82 may
be grooved at the forward end on the surface adjacent the belt 258
so as to increase the frictional grip. For convenience of
machining, and also to allow substitution of a sm~oth~surfaced end
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~7~7
portion where it is found that the grooves axe unnecessary for a
satisfactory grip or that they unduly tear, deform or wear a
particular foil, the expander arms have separable end pieces 81a
and 82a on which the grooves 290 are formed, as shown in Figures
15 and 15a. The grooves 290 extend parallel to the support arm
101 and are of saw tooth profile with their inclining faces
sloping away from the inner edges of the pieces 81a and 82a so as
to give a configuration tending to resist trans~erse withdrawal
of the foil. The end pieces 81_ and 82a are retained in abutting
alignment with the main portions of the arms 81 and 82 by
securement to th2 block 256 of the fine adjustment device with
bolts 300, and are further retained on the support arms 101 by
the bolt 248 at the forward end of the support arm 101.
Referring now to Figure 12, the drive mechanism for the
b~lts 258 and rollers 87 is shown. Except as noted below this
is similar to the previously-described arrangement illustrated in
Figure 3. The shaft 146 in this instance is journalled in a
bracket 291 on the outer side of the side plate 89. The gear 144
meshes with the spur gear 147 on a parallel shaft 148 journalled
in the support arm 101 which turns the pulley 259 driving the belt
258. The sprocket lÇ4 is coupled through chain 165, to a sprocket
wheel 166 connected on a shaft 167 ]ournalled in a bracket 292 on
the outer side of one side plate 210. The shafts 146 and 167 are
coaxial with one another and with the dowel pins 246 about which
the expander arms 81 and 82 swing, so that when the angle o~ the
expander arms is adjusted, the gear 147 and 171 rock around the
gears 144 and 169, respectively, without losing dri~ing
engagement.
The operation of the machine, is generally as described
in connection with the en~odiment o~ Figures 1 to 10, but the
guide plate 228 ~hould initially be in open position and the rollers
87 in separated position until after the web has its edges
gripped between the belts and the armsO The guide pl~te 228 and
- 24 -
37
the rollexs 87 are then restored to the closed position so that
in subsequent running of the machine, the rollers 87 feed the
web forwardly and the plates 227 and 228 smooth out the feed of
the web ~nd will deliver it directly to the expander arms 81 and
82 in alignment with the rear edges of the arms. The spacing
between the plates 227 and 228 is selected so that with the
thickness of web 58 to be employed, the web 58 can run freely
between the plates yet will be positively guided without
opportunity for misalignment. The expansion then follows in the
same manner as described previously in connection with the machine
of Figures 1 to 10. With the present arrangement, it will be
noted that adjustment of the portion of the arms 81 and 82 noted
previously, in order to obtain uniformly sized and orientated
diamond shaped meshes, can be carried out using the ine adjustment
member 251.
The degree of lateral expansion of the web, l.e. the
increase in the width of the expanded web as compared with the
original web can be varied by swinging the expander arms 81 and
82 towards or away from one another about the pi~otal axes of the
dowel pins 246.
The expander machine of Figures 11 to 19 can accommodate
input webs of varying widths, and the permissible range of
variation of the width is approximately twice the transverse width
of the belts 258 which are employed. Within these limits, the
edges of the web can be gripped between the area of overlap between
the belts 258 and the expander arms 81 and 82.
The form shown in the drawings, in which belts 258 are
supported so as to extend beyond the inner inclining edges of the
expander arms 81 and 82 at the front end is ~specially
advantageous since it allows the web to be expanded across its
full width without leaving any unexpanded selvedge and without
deforming the edges of the web out of the general plane of the
unexpanded product. As can be seen in Figure 16, towards the
- 25 -
forward end of the expander arms, the belt 258 extends inwardly
beyond the inner inclining edges of the expander arms. It has
been found that in practice this does not interfere with the free
expansion of the web, since as can be seen in Figure 16, the
expanded material 291 slopes sharply away from the belt 258 at the
point where it slips over the edge of the expander arm 81.
Forwardly of the region shown in Figure 16, the edge portions of
the web 58 slips over the inclining inner edges of the arms 81 and
82, and it is found that with the appropriate angled orientation
between the inner edges of the arms 81 and 82 and the slits in
the web 58, as explained above with reference to Figure 3, the
edge portions of the web 58 are expanded to the same desired
extent as the interveniny parts of the web which have been
expanded before the web reaches the forward end of the machine.
When producing expanded webs for use as anti-explosion
fillings in fuel containers, we prefer to employ metal, e.g.
aluminium alloy foils of thickness of from 0.0005 to 0.012
inches. In order to obtain optimum explosion-resistant properties,
it is preferable to employ meshes with certain selected mesh
dimensions. Preferably the expanded mesh has a longest width
dimension, that is the distance between ~he longitudinal
extremities of longitudinally adjacent meshes (the distance A-A
in Figure 3) o from 1/8 to 1-1/4 inches; a short width dimension,
that is the distance measured between the centres of laterally
opposing connecting portions (the distance between the centres
of the connection portions 292 and 293) of from 1/16 to 5/8 of
an inch, and a strand width (the dimension B-B) of from 1/32 to
7/32 of an inch.
We prefer to expand the lateral dimension of the foil by
about 284% in the direction extending transversely to the slit
lines. As a result of this expansion the foil contracts in the
direction extending longitudinally of the slit lines to about
87~ of its oxiginal dimension.
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Merely by way of example, it can be mentioned that with
the above degree of expansion, a piece of foil originally
14 1/4 x 12 inches (area 171 sq. inches) would expand to
40 1/2 x 10 1/2 inches (area 425 sq. inches). This represents
an area expansion of 248%.
For use as an anti-explosion filler, the expanded mesh
produced is laid in superimposed layers to form a bale which is
then employed as a filler mass occupying the internal space
within a fuel container.
The bale may be formed by, for example, winding the
expanded mesh up into a cylindrical coil, folding it, or
severing the web into uniform pieces which are then stacked one
on top of the other.
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