Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to apparatus for forming
articles from strip-shaped felts of fibrous material, for example
glass fibre insulating wool, containing a hardenable bonding
material, e.g., an uncured thermo-setting bonding material.
One important application of the present invention is to
the manufacture of longitudinally split cylindrical thermal
insulation coverings for hot and cold pipes, which coverings are
commonly referred to as "one-piece pipe insulator sections" and
are kerfed to enable them to be opened sufficiently wide to be
fitted over a pipe, after which they snap into a closed condition
around the pipe when released.
However, the invention is not restricted to the manu-
facture of one-piece pipe insulator sections, and may with advan-
tage be employed for making other articles, for example of
rectangular, segmental, arcuate or irregular cross-section, from
felts of fibrous material.
In United States Patent No. 3,912,572 issued October 14,
1975 to John W. Lacon, there is disclosed an apparatus and a
method which employ stationary forming surfaces between which a
felt is pulled to d~eform the cross-section of the felt, which is
then cured by discharging hot gas through the felt. The forming
surfaces are provided on cylindrical inner and outer dies, the
outer die being formed in one piece and having openings for the
passage of the hot gas through the outer die to and from the
felt. This prior apparatus can be adapted to the manufacture of
different product sizes by replacem~ntof the inner and/or the
outer die. With this prior apparatus, the hot gas is discharged
once inwardly through the die, and then withdrawn outwardly
through the die to complete the curing of the felt.
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It has subsequently been found that, in order to ensure
satisfactory curing of the felt even when the speed of advance of
the felt through the dies, and the size of the final product, are
considerably increased, a more effecting curing of the felt by the
hot qas is required. Nevertheless, in order to ensure economical
utilization of the relatively expensive production line re~uired,
it is also important that the dies should be readily replaceable
for adapting the production line to a range of different product
sizes.
Accordingly, it is an object of the present invention
to provide apparatu.s, for forming articles from a strip-shaped
felt of fibrous materials which enables both improved curing of
the felt and also facilitates replacement of a die employed for
forming the felt.
According to the present invention, there is provided
apparatus for forming articles from a longitudinally advancing
strip-shaped felt of fibrous material containing hardenable bond-
ing material, the apparatus comprising a die for sliding contact
with the felt along the length of the felt during advance of the
felt through the die; the die being formed with openings for the
flow of hot gas through the die for hardening the bonding mater-
ial and comprising a plurality of separable die sections; means
for releasably securing the die sections in mutual longitudinal
alignment along the path of advance of the felt; a housing sur-
rounding the die, a plurality of chamber partitions dividing
space within the housing into gas inlet chambers and gas outlet
chambers, the die extending through the chambers and openings
in the partitions; gas inlet means communicating with the gas
inlet chambers for supplying hot gas thereto, gas outlet means
communicating with the gas outlet chambers; and closure means
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extending around the die and closing the openings so that the
hot gas flows through the die from the gas inlet chambers to the
gas outlet chambers.
By the use of a pluralityof separabledie sections,the
die can bemade considerablylonger than was possible hitherto,
thus providing a longer length of die through which the hot gas
can be discharged, with consequential improvement of the curing
of the felt. However, because these die sections are readily
separable, the die can be disassembled into readily manageable
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parts, which facilitates mounting of the die in the apparatus and
removal and replacement of the die.
Moreover, the increased length of the die also enables
the number of "passes" of the hot gas through the felt to be
increased.
Preferably, the apparatus comprises a plurality of
chambers each extending around the die, the chambers being dis-
posed in succession along the die, a hot gas inlet passage for
supplying hot gas to one of the chambers for discharge therefrom
through perforations in the die and into the felt, a hot gas out-
let passage communicating with another of the chambers for
discharge of the hot gas therefrom, the chambers being separated
by partitions formed with openings through which the die extends,
the die having a cross-section smaller than the openings, and the
securing means comprising readily removable closure means extend-
ing around the outer die for closing the openings.
The chambers may communicate with one another through
valves which are adjustable for controlling the flow of the hot
gas through the chambers.
The invention will be more readily understood from the
following description of an embodiment thereof given by way of
example with reference to the accompanying drawings, in which:-
FIGURE 1 shows a side view of apparatus for forming one-
piece pipe insulation sections;
FIGURE 2 shows a view taken in vertical longitudinal
section through the forming section of the apparatus of Figure l;
FIGURE 3 shows a partially broken-away view in perspec-
tive of a housing enclosing the forming section of Figure 2 and
of a burner, pump and ducting arrangement for suppling hot gas to,
and exhausting hot gas from, the housing;
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FIGURE 4 shows a view taken in horizontal longitudinal
section through the housing of FIGURE 3;
FIGURE 5 shows a broken-away view, taken in cross-section
along the line V-V of Figure 6, through one of a plurality of
closure plates and an associated quick-release securing device
supporting the outer die in the housing of Figures 2 to 4; and
FIGURE 6 shows a view taken in the direction of the arrow
A of Figure 5.
The apparatus shown in the drawings is intended primarily
for the continuous production of longitudinally split cylin-
drical one-piece pipe insulation sections from uncured mineral
wool felt containing a hardenable bonding material in the form,
for example, of an uncured resin. However, this apparatus can
readily be adapted for the formation of articles of various
cross-sections from the same material.
Figure 1 shows a diagrammatic side view of a production
line employing a supply coil 210 of uncured strip-shaped mineral
wool felt 211, containing a hardenable bonding material in the
form of an uncured resin. The felt 211 is provided in the roll
210 cut to the requi:red width and is provided with a tensile
strengthener, for example a scrim backing.
An auxiliary supply roll 210A is provided for supplying
the felt 211 when the supply roll 210 has become exhausted, and
an automatic splice mechanism 212 is provid~d for splicing
together the ends of successive lengths of the felt 211 from the
supply roll 210 and the auxiliary supply roll 210A.
A conveyor mechanism 213 conveys the felt 211 from the
supply roll 210 and the auxiliary supply roll 210A to a further
conveyor 214, from which the felt 211 passes into a forming
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section indicated generally by reference numeral 215, which will
be described in greater detail hereinafter.
Before the felt 211 enters the forming section 215, it
passes beneath a felt hold-down roller 216, which serves to
correctly guide the felt 211 to the forming section 215.
In the forming section 215, the felt 211 is deformed to
the required product cross-sectional shape and cured.
The cured felt is pulled, from beyond the forming section
215, by a gripping and pulling mechanism indicated generally by
reference numeral 217, which is in the form of a pair of driven
endless belts 218, gripping opposite sides of the cured felt 211.
Beyond the gripping and pulling mechanism 217, the cured
felt 211 passes a longitudinal slitting cutter, indicated -
generally by reference numeral 220, which may be required to form
a longitudinal slit along one side of the cured felt.
A jacketing material 221, for example aluminum foil,
supplied from a jacketing material supply roll 222 is then
wrapped around the cured felt 211, after which the cured and wrap-
ped felt is aut into sections of the required length by a flying
transverse cut-off mechanism 223, the cut sections be~ng packed
in an automatic boxing machine indicated generally by reference
numeral 224.
The forming section 215 will now be described in greater
detail with reference to Figures 2 to 6.
At the inlet end of the forming section 215, there is -~
provided an inlet cone 228 for deforming the cross-sectional
shape of the felt 211, which is flat prior to the entry of the
felt 211 into the inlet cone 228, into an annular cross-section,
to thereby wrap the incoming felt 211 around an inner forming
surface provided on the exterior of a cylindrical inner die or
mandrel 229.
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The inner die 229 extends into, and is releasably supported
in and radially inwardly spaced from, the inlet end of a cylind-
rical outer die, indicated generally by reference numeral 230.
The outer die 230 is formed of six cylindrical outer die
sections 231A through 231 E, which are secured together in end-
to-end relationship by telescopic interengagement of the end
portions thereof.
The outer die sections 231B through 231E are formed with
perforations 232 to allow hot gas to pass th~rethrough, as will
be described in greater detail hereinafter.
The outer die 230 extends through a casing or housing
indicated generally by reference numeral 234, which serves to
confine the hot gas flow to and from the outer die 230.
As shown in Figure 2, the housing 234 has opposite end
walls 235 and 236, a top 237 and a bottom 238. A plurality of
transverse vertical partition walls or bulkheads 240 are spaced
apart along the length of the housing 234 and extend transversely
thereof.
A longitudinal partition, formed of a plurality of
horizontal transverse partition walls 241 through 245, extends
between the end walls 235 and 236 and the transverse vertical
partition walls 240 and serves to separate the upper portion of
the interlor of the housing 234 from the lower ~ortion thereof.
Each vertical partition wall 240 has an opening 240A within the
upper portion of the housing interior to allow gas flow along
the length of the upper portion.
Each of the horizontal transverse partition walls 241
through 245 is formed with a gas flow opening 247, which may be
closed by means of a valve 248.
Each of the valves 248 has a threaded shaft 249 extending
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in threaded engagement with a sleeve 250, which is fixed to the
housing top 237, the upper end of the shaft 249 being formed with
a square-section head 251 for engagement with a turn-key (not
shown). On rotation of the shaft 249 by means of this turn-key,
a valve plate 252 at the lower end of the valve 248 can be raised
or lowered to close or open the respective gas flow opening 247.
The lower portion of the housing 234 is separated by the
vertical partition walls 240 and releasable closure plates 258
through 263, which will be described in greater detail hereinafter,
into a plurality of die chambers 252 to 256.
Referring now to Figure 3, the front of the housing 234
is closed by a wall 265. The upper portion of the housing 234 is
closed at its rear by a rear wall 266.
. At its lower portion, the housing 234 has a rearward
extension 269 having a top 267 and a rear wall 268.
As can be seen from the plan view of the housing 234 shown
in Figure 4, which vi~w is partially broken away in section to
reveal the interior of the rearward extension 269 and parts of
the die chambers 252 through 256, one of the vertical partition
walls 240, which is the first of the vertical partition walls 240
in the direction of advance of the felt 211, extends rearwardly
across the interior of the rearward extension 269 to divide the
latter into a gas inlet housing portion or chamber 269A and a
gas outlet housing portion or chamber 269B, the remaining vertical
partition walls 240 being formed with square openings 240B and
the die chambers 254 and 256 communicating with the gas outlet
chamber 269B through openings 266A and 266B in the rear wall 266
to allow the hot gas to escape from the die chambers 254 and
256 to the gas outlet chamber 269B. The gas inlet chamber 269A
communicates with the die chamber 252 through an opening 266C in
the rear wall 266~
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A hot gas supply duct 270 communicates with the gas inlet
chamber 269A, and a hot gas return duct 271 communicates with gas
outlet chamber 269B.
The hot gas supply duct 270 extends from a burner housing
272 provided with a gas burner 273.
A gas pump 274, driven by an electric motor 275, communi-
cates with the burner housing 272.
A by-pass duct 277, communicating with the air supply
duct 270, extends to the inlet of the air pump 274, and the hot
gas return duct 271 communicates with the by-pass duct 277.
An exhaust stack 278 extends upwardly from the burner
housing 272.
The hot gas supply duct 270 is provided with an inlet
valve 280 for controlling the flow of hot gas into the housing
234, and the hot gas return duct 271 is provided with an exhaust :
valve 281 for controlling the exhaustion of the hot gas from the
housing 234.
A by-pass valv.e 282 is provided in the by-pass duct 277
for controlling flow of the hot gas from the hot gas supply duct
270 to the gas pump 274, and the exhaust stack 278 is provided
with a damper 283.
A compressed air inlet pipe 285 has a downwardly extending
coiled section 286 associated with a burner 287, and communicates
through a flexible hose 288 and an inlet pipe 289 with the
interior of the inner die or mandrel 229 (Figure 2), which is
provided with hot gas outlet openings 290.
The manner in which successive sections of the outer die
are connected together and supported in the housing will now be
described with reference to Figure 5, which illustrates the
interconnection of the ends of the outer die sections 231B and
231C.
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1080~;1)4
The outer die section 231B is provided with an end sleeve
291 welded thereto, and the outer die section 231C is provided
with an end sleeve 292 welded thereto. A further end sleeve 293,
welded around the end sleeve 292, telescopically receives the end
sleeve 291.
The vertical transverse partition wall 240, shown broken
away in Figure 5, separates the successive chambers 253 and 254
(Figure 2) of the housing 234, and is formed with an opening 295
which is of considerably larger cross-section than the outer die
230lso as to be able to accommodate replacement outer dies of
different cross-sectional sizes and shapes. The opening 295 is
closed by a respective one of the closure plates 260 extending
around the outer die 230. A similar opening 295 is provided in
each of the other vertical partition walls 240 and the end walls
235 and 236.
An annular locating member 296 is secured to the vertical
transverse partition wall 240 by bolts 297, and a die locking ring
299, provided with handles 300, releasably secures the closure
plate 260 in the position shown in Figure 5.
The die locking ring 299 is retained in position, while ~ -
being allowed to be rotatable relative to the locating member 296,
by means of two locking ring retainers 304. Bolts 305 in threaded
engagement in bushes (not shown) secured to the vertical trans-
verse partition wall 240 serve to retain the locking ring
retainers 304.
For receiving the outer die 230 therethrough, the closure
plate 260 is formed with a circular opening, the edge of which is
in the form of a knife edge 260A, which engages a raised portion
307 of the end sleeve 293 in a slidable manner to allow for
expansion and contraction of the sections of the outer die 230 as
the latter is heated and cooled.
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Die retaining rings 308 extend around the inner edge of
the closure plate 260 and are secured thereto by bolts 309 and
nuts 310, the die retaining rings 308 extending inwardly at
opposite sides of the end sleeve raised portion 307 for retaining
the latter.
The rotatable die locking ring 299 releasably secures the
closure plate 260, and thus the outer die 230, in position in the
opening 295. To this end, the die locking ring 299 is formed with
a circular inner periphery interrupted by diametrically opposite
flat faces 311, and the closure plate 260 has a circular outer
periphery interrupted by corresponding diametrically opposite flat
faces 312. The inner periphery of the die locking ring 299 and
the outer periphery of the closure plate 260 are dimensioned so
that the closure plate 260 can be displaced through the die
locking ring 299, in a direction parallel to the axis of the outer
die 230, to enable the closure plate 260 to be moved into or out
of the position in which it is shown in Figure 5 when the die
locking ring 299 is rotated into an unlocked position.
The rotation of the die locking ring 299 is effected by
engagement of a suitable tool (not shown) in the handles 300,
which are shown in full lines in their locked positions, and in
broken lines in their unlocked positions, in Figure 6.
In the unlocked position of the die locking ring 299,
the flat faces 311 of the die locking ring extend parallel to
the flat faces 312 of the closure plate 260 and therefore the
closure plate 260 can be displaced past the flat faces 311.
When the die locking ring is rotated into its locked
position, the flat faces 311 and 312 are no longer parallel, and
the flat faces 311 of the die locking ring 299 overlap the cir-
cular portion of the outer periphery of the closure plate 260,
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thus preventing displacement of the latter through the die
locking ring 299. In this manner, the closure plate 260 is
locked in the position in which it is shown in Eigure 5.
The operation of the above-described forming section 215
is as follows.
As the felt 211 is wrapped around the inner die 229 and
advances past the inner die 229 and along the outer die 230, the
inner surface of the felt is at least partially cured by hot air
supplied from a compressed air source (not shown3 through the
pipes 285, 288 and 289 and heated by the burner 287, this air
being expelled from the hot air discharge openings 290 in the
inner die 229. The felt 211 is also heated by conduction from
the outer surface of the inner die 229 of heat provided by elec-
trical heating elements 314 within the inner die 229.
The hot gas supplied into the die chamber 252 from the hot
gas supply duct 270 circulates around the outer die sections 231A
and 231B and passes through the overlying hot gas flow opening 247
and the upper portion of the housing 234, as indicated by arrows
A, to the die chamber 253 and 255. ~-
In the chambers 253 and 255, this hot gas flows inwardly
through the perforations 232 in the outer die sections 231B and
231D and inwardly through the thickness of the felt, which is now
cylindrical. This hot gas then passes along the interior of the
felt and outwardly through the outer die sections 231C and 231E,
and thence into the gas outlet chamber 269B as shown in Figure 4,
and into the hot gas return duct 271 for recirculation.
As will be apparent, the valves 248 can be opened or
closed to vary the rate of flow of the hot gas to the chambers
252 and 256 as may be desired to produce optimum curing of the
felt-
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The rate of flow of the hot gas to and from the housing
234 is controlled by the valves 280 to 282, and excess hot gas
is vented through the stack 278 under control of the damper 283.
When it is desired to replace the inner and outer dies,
cover plates or doors 315 (Figure 4) are removed from access
openings (not shown) in the front wall 265 of the housing 234 to
provide access to the interior of the housing 234.
The closure plates 258 to 263 are then removed, in
succession, by firstly rotating the handles 300 and therewith
the die locking rings 301 to release the closure plates. The
outer die section 231A to 231E can then be successively discon-
nected from one another and withdrawn from the housing 234,
together with the closure plates 258 and 263.
The outer die can then be replaced by a new outer die
(not shown) of, for example, larger cross-section.
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