Note: Descriptions are shown in the official language in which they were submitted.
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APPARATUS FOR MANUFACTURING FLEXIBLE
CORRUGATED TUBES
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The present invention relates to an improved
apparatus for forming a longitudinally corrugated thin
strip into a flexible corrugated tube generally like
that disclosed in Us Patent 4,141,385, issued February
27, 1979 to Emil Cigarette.
The prior art apparatus known to applicant which
is the most closely related to the present apparatus
is that of US. Patent 4,058,997, issued November 22,
1977 to Emil Surety.
Apparatus of the type disclosed in US. Patent
4,058,997 maybe used to produce tubes of different
diameters only by removing Rome the apparatus a plate
which carries a circle of forming rollers which are
tangent to a circle of one diameter, and replacing that
plate with another one which carries rollers that are
tangent to a circle ox a different diameter. As a
result, switching the machine from the manufacture of
a tube of one diameter to that of another diameter is
quite a complex and time consuming job.
A large percentage of the flexible corrugated
tubes made in this type of machine are used four air
conditioning ducts, and any particular air conditioning
installation usually requires ducts in several different
sizes. Ideally, a portable duct curling machine is
used to produce duct as needed at a job site, and there
are portable units for this purpose. However, the port-
able units, like the unit of the Cigarette US. Patent
No. 4,058,997, may be used to produce tubes of different
sizes only by replacing an entire front plate which
carries the curling rollers that are tangent to a circle
of a particular diameter. This means that several
interchangeable curling die plates must be carried with
the portable machine.
The apparatus of Patent 4,058,997 has a mechanism
illustrated in Fig. 5 of the drawings for forming in
overlapping turns of the helical tube a lock of the type
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illustrated in patent 4,141,385. Such a lock has certain
disadvantages which can be eliminated by a lock of a
different type.
Finally, portable apparatus of a type heretofore
developed by the present inventor in Germany utilizes
a cassette to receive a reel of precorrugated strip
which is used in the fabrication of the flexible corrugated
tube.
In one broad aspect, the invention pertains to apparatus
for helically curling longitudinally corrugated thin
strip material into a flexible corrugated tube. The
apparatus comprises, in combination, a curling unit
and a cassette, the curling unit comprising a base,
with two forwardly extending rotatable driven input
rollers carried on the base near one side thereof, the
input rollers having inter meshing arcuate lands and
grooves forming snip which matches the corrugations
of a strip of material to be helically curled. Two
forwardly extending rotatable driven output rollers
are supported on the base, the output rollers having
inter meshing arcuate lands and grooves forming a nip
to receive a strip of material from the input rollers.
Idler rollers are supported on the base which have arcuate
lands and grooves to guide the strip of material from
the input rollers in a helical path in which each successive
turn of the strip passes through the nip of the output
rollers in partially overlapped relationship with the
strip entering the output rollers. Locking means are
provided for intermittently crimping overlapping parts
of the strip to lock the parts to one another. The
cassette has a frame with a plurality of sides and means
on the frame to rotatable mount a reel of the thin strip
material. A strip out feed opening is in one of the
frame sides, and two guide rollers are in the out feed
opening, the guide rollers having inter meshing arcuate
lands and grooves forming a nip which matches the corrugations
in the strip of material. Means detachably mount the
cassette on the base with the nips of the guide rollers
and of the input rollers immediately adjacent one another
and substantially coplanar.
The invention also comprehends a cassette to receive
a reel of longitudinally corrugated thin strip material
which is to be helically curled in a curling apparatus
Lo
-pa-
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to form a flexible corrugated tube, the curling apparatus
having driven input rollers with inter meshing lands and
grooves forming a nip to receive the strip. The cassette
comprises, in combination, a frame with a plurality
of sides, means on the frame to rotatable mount a reel of
the longitudinally corrugated thin strip material, a
strip out feed opening in one of the frame sides, and two
guide rollers in the out feed opening, the guide rollers
having inter meshing arcuate lands and grooves which
form a nip that matches the corrugations in the strip
of material. Means are provided for connecting the
cassette to a curling apparatus with the nips of the guide
rollers and of the curling apparatus input rollers
immediately adjacent one another and substantially
coplanar.
More particularly, the disclosed invention provides
a portable apparatus for manufacturing flexible corrugated
tube which includes a cassette to receive a reel of
longitudinally corrugated strip, and an out feed opening
of the cassette is provide with a pair of guide rollers
which have inter meshing arcuate lands and grooves forming
a nip that matches the corrugations of the strip, and
when the cassette is hung on the frame of the curling
apparatus, the nip of the guide rollers is immediately
adjacent and coplanar with the nip of driven indeed
rollers which also exactly match the corrugations of
the strip. Accordingly, the feed of the strip into the
curling apparatus is carefully controlled, and any
deviations in the corrugations or possible deformations
in the edges of the strip are eliminated before the
strip enters the curling rollers.
Further, the rollers which are arranged in a
circle to determine the diameter of the tube being
produced by the apparatus are carried upon a spider
which is vertiçallyadjustable relative to strip out-
feed rollers that drive the strip into the circular array
of curling rollers. The spider is movable vertically
relative to the out feed rollers so as to change the
distance from the nip of the out feed rollers to the
longitudinal axis about which the curling die rollers
form a circle, and at the same time all of the curling
die rollers are radially adjustable with reference to
that axis so as to permit the apparatus to be very
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simply adjusted to produce tubes of different diameters.
In the preferred embodiment described, a single
manual adjusting crank serves to move the spider Yen-
tidally relative to the nip of the out feed rollers,
and at the same time moves all of the curling die rollers
radially to accomplish the desired adjustment of die-
meter in a single operation.
The apparatus of the present invention may be
readily adjusted to produce corrugated tube from about
50.8 mm (2 inches) to about 508mm (20 inches) in die-
meter.
The coil locking apparatus of the present invent
lion has jaws which indent the two sides of a cargo-
lion, rather than squashing the top of the corrugation
as taught in patent 4,141,385. The resulting lock is
less obtrusive and thus produces a better looking tube
than the prior art.
Fig. 1 is schematic perspective view of the
present curling apparatus to show the relationship
between the curling unit and the cassette, parts being
omitted for clarity;
Fig. 2 is a fragmentary view of a part of a eon-
rugated strip curled into a segment of a tube;
Fig. 3 is a front elevation Al view of the curling
apparatus of the invention with parts broken away for
clarity and with only the immediately adjacent part of
the cassette illustrated;
Fig. PA is a fragmentary sectional view on an
enlarged scale taken substantially as indicated along
the line AYE of Fig. 3, appearing with Figs. 1 and 2;
Fig. 4 is a fragmentary sectional view on an
enlarged scale, with parts broken away, taken sub Stan-
tidally as indicated along the line 4-4 of Fig. 3;
Fig. 5 is a fragmentary sectional view taken sub-
staunchly as indicated along the line 5-5 of Fig. 4;
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Fig. 6 is a fragmentary sectional view taken sub-
staunchly as indicated along the line 6-6 of Fig. 3;
Fig. 7 is a fragmentary sectional view taken sub-
staunchly as indicated along the line 7-7 of Fig. 4;
Fig. 8 is a fragmentary sectional view on an
enlarged scale, taken substantially as indicated along
the line 8-8 of Fig. 4, illustrating the coil locking
mechanism of the present apparatus;
Fig. 9 is a fragmentary sectional view on an
enlarged scale, taken substantially as indicated along
the line 9-9 of Fig. 8;
Fig. 10 is a fragmentary section on an enlarged
scale taken substantially as indicated along the line
10-10 of Fig. 8;
Fig. 11 is a fragmentary schematic view of the
curling die rollers and the forming strip;
Fig. 12 is a diagrammatic view illustrating the
relative positions of the curling die rollers with
respect to the out feed rollers and one another in two
; 20 different adjusted positions of the spider;
Fig. 13 is a fragmentary elevation Al view, which
is partially schematic, illustrating a bending device
in detail, and showing the curling unit adjusted to
form a tube of very small diameter; and
Fig. 14 is a fragmentary sectional view taken
substantially as indicated along the line 14-14 of
Fig. 13.
; Referring to the drawings in detail, and refer-
ring first to Figs. 1-3, a tube forming apparatus, in-
; 30 dilated generally at 18, includes a curling unit, India
- acted generally at 20 and a cassette 21 from which the
unit 20 receives precorrugated aluminum strip S to form
into flexible tube T.
The tube forming apparatus 20 has a base 22 that
includes a frame 23, and cooperating input rollers 24
and 25 are mounted on the frame to feed the procure-
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grated strips S relieved from the cassette 21.
The curling die unit 20 also includes an upright support 26 which has a base plate AYE that is rotatable
on the base 22 on a vertical axis as will be described
in more detail; and output rollers 27 and 28 are car-
:; fled upon the support 26 to receive the strip S from the
input rollers 24 and 25 and feed it into a bending de-
vice 119 (detailed in Fig. 13), and a series of curling
die rollers 29-35 which are journal Ed on respective
spindles AYE that are mounted in a circular con fig-
unction on a curling die base 36 that is vertically ad-
just able on the upright support 26. The spindles AYE-
AYE are readily removed.
The curling die base 36 includes a roller sup-
15 porting spider 37, a frame 38 and guide posts AYE that
are guided in sleeves 39 which are mounted on a cross
bar 40 on the rear of a gear housing 41 that is fixed
on the upright support 26. The radial distance of
each of the rollers 29-35 form a center AYE of the
roller supporting spider 37, which coincides with the
longitudinal axis of a forming tube T, maybe adjusted
so as to allow the manufacture of flexible tubes having
different diameters. Furthermore, when the radial disk
lance of the rollers 29-35 from the center AYE is
25 changed, the spider 36 and the rollers 29-35 are moved
vertically on the support 26 toward or away from the out-
: put rollers 27 and Sue that the center AYE of the spit
don 37 always coincides with the longitudinal axis of
the flexible tube being formed. During this vertical
adjustment of the spider, the support 26 is rotated on
the base 22 about its vertical axis, so the angle of
the helix formed by spiral winding the corrugated strip
S matches the diameter of the forming tube T. A small
tube requires a large helix angle, while a large tube
requires a small helix angle.
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: Referring especially tweaks. 4-7, the vertical
: adjustment of the curling die base 36 and the radial
adjustment of the rollers 29-35 are both accomplished
by using a hand crank 42 to turn a spindle 43 which
carries an adjusting bevel drive gear 44 that drives
a cluster of bevel pinions 45-52 (see Fig. 7).
The bevel pinion 45 is attached to the upper end
I of an upright adjusting squire which extends within
a screw housing 54 of the curling die base 36 and is
LO vertically movable through a threaded nut 55 which is
disposed within the housing 54 and is part of a block
: that extends outwardly through an elongate opening of
the housing 54 and is mounted upon the gear housing 41.
Rotation of the spindle 43 causes a corresponding rota-
lion of the upright screw within the nut 55, and
this causes the entire curling die base 36 to move Yen-
tidally with respect to the output rollers 27-28 which
are carried on the gear housing 41.
Secured to the frame 38 is a cam plate 56 that
includes a cam slot 57 which traverses a cam follower
58 that is fixedly secured to the base 22. vertical
movement of the curling die base 36 causes the cam slot
57 to traverse the cam follower 58, and this causes the
upright support 26 -to rotate about its axis, which is
the axis of a vertical shift 59~ that is bearing supported
within the base 22. A base plate locking bolt 26B
extends through an arcuate slot 26C in the base plate
AYE of the upright support 26, and the locking bolt
26B is loosened when the tube diameter is to be changed.
The pivotal movement of the parts changes the angle of
the helix to match the diameter of the tube ping formed,
and the amount of the pivotal movement is controlled by
the shape of the cam slot 57.
As seen in Fig. 7, the pinions 46-52 are part of
spindle adjusting means 60 for adjusting the radial
positions of the curling die roller spindles AYE.
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The pinions 46-52 are mounted on respective radial
adjusting screws 61-67 that are carried within radial
screw housings 68-74 of the spider 37. The radial
adjusting screws 61-67 engage respective spindle nuts
75-81 which are parts of slide blocks on which the
spindles AYE are respectively mounted. Therefore,
all the curling die rollers 29-35 move radially in
; unison toward or away from the center AYE of the roller
spindle 37 in response to rotation of the spindle 43.
Thus, the following three actions occur when the
spindle 43 is rotated:
1. The center AYE of the spider 37 moves Yen-
tidally toward or away from the output rollers 27-28,
which remain stationary;
2. Each of the rollers 29-35 moves in a radial
direction relative to the center AYE; and
3. The upright support 26 rotates about the
axis of the vertical shaft 59 to change the helix angle.
As best seen in Figs. 3 and 4, a motor 82 is
mounted upon the base 22 and is connected through a
timing belt drive 83 to the upright shaft 59. The
shaft 59 is coupled via bevel gears 84-85 and a timing
belt drive 86 to a lower output shaft AYE which mounts
the lower output roller 27. The lower output shaft AYE
is also coupled through gears 87-88 to an upper output
shaft AYE which mounts the upper output roller 28.
Referring also to Fig. 6, the input rollers 24-
25 are driven by means of a second timing belt drive 89
from the upright shaft 59 to a shaft 90. A bevel gear
30 91 on the shaft 90 meshes with a bevel gear 92 on a
jack shaft 93 to drive a further timing belt drive 94
for a lower input roller AYE which mounts the lower
input roller 24. The lower input roller shaft AYE,
in turn, is connected by gears 95 and 96 to an upper
input roller shaft AYE which mounts the upper input
roller 25.
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referring also to Fly. 6, the input rollers 24-
25 are driven by means of a second timing belt drive 89
from the upright shaft 59 to a shaft 90. A bevel gear
91 on the shaft 90 meshes with a bevel gear 92 on a jack
shaft 93 to drive a further timing belt drive 94 for a
lower input roller AYE which mounts the lower input roll-
or 24. The lower input roller shaft AYE, in turn, is
connected by gears 95 and 96 to an upper input roller
shaft AYE which mounts the upper input roller 25.
lo Referring now to Fig. 1, the cassette 21 has a
frame, indicated generally at 97, with a plurality of
sides including a rear side 98, lateral sides 99 and lo,
and a front side loll A spindle 102 is mounted on the
rear side 98, there is a strip out feed opening AYE in
the lateral side 99, and the front side 101 consists of
a pair of doors 103 on hinges 104 mounted on the lateral
sides 99 and lo. The spindle 102 receives a reel 105
of the corrugated strip S.
Upper mounting brackets 106 and lower brackets 107
detachably connect -the cassette 21 to the frame 23 of
the curling unit 20, with the strip out feed opening AYE
immediately adjacent the input rollers 24 and 25. In
the opening AYE is a pair of strip guide rollers 108-
lo which have a nip coplanar with that of the input
rollers 24 and 25 when the cassette is mounted upon the
curling frame 23.
When a new reel 105 of corrugated strip S is
mounted in the cassette, the end of the strip must be
guided through the nip of the guide rollers 108-109,
through the nip of the input rollers 24-25, and through
the nip of the output rollers 27-28. The end of the
strip is then fed into tangency with the curling die
roller 99, or alternatively to the inner side of a
bending roller if that is used, as hereinafter described.
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As the corrugated strip S is removed from the
reel 105, the guide rollers 108-109 assure that it will
be properly fed into the indeed rollers 24-25 as the
outer diameter of the strip remaining on the reel de-
creases. When the supply of strip on a reel 105 is ox-
haunted, the front doors 103 are opened, the exhausted
reel is removed and a furl reel is placed on the spindle
102, and the new strip is threaded through the guide
rollers 108-109, etc.
It is apparent from the foregoing description
that the guide rollers 108-109, the input rollers 24-25,
and the output rollers 27-28, must all have arcuate lands
and grooves which intermesh to form a nip which matches
the corrugations of a strip S. The curling die rollers
29-35 also have such lands and grooves. This is thus-
treated in Figs. 8-10, which show the output rollers 27-28
in conjunction with the strip S, and a locking mechanism
which will be described in detail hereinafter. Accord-
tingly, it will be understood that all the rollers which
feed or guide the strip have identical lands L and
grooves G as indicated in Fig. 9.
Referring further to Figs. 8-10, there is thus-
treated a mechanism 110 for locking together overlapping
layers of the corrugated strip as it is being formed
into a flexible tube. The lower output roller 27 has
sub portions 27B and 27C which are spaced to provide a
gap 27D in which a bushing 111 is mounted on the lower
output shaft AYE. The bushing carries a crimping wheel
consisting of a collar 112 and several equally spaced
bifurcated crimping spokes 113 having resilient arms
AYE and 113B of spring steel which normally abut the
adjacent ends of the sub portions 27B and 27C.
The crimping wheel rotates generally with the
lower output roller 27, though it may rotate relative
to the roller. As a bifurcated spoke 113 enters the
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nip of the rollers 27 and 28, as shown in Fig. 10,
a pair of lands Lo and Lo of the upper roller 28, which
are spaced by double the width of a corrugation, contact
respective gemming surfaces 114 and 115 of the arms AYE
and 113B to force the arms toward one another so that
respective opposed crimping jaws 116 and 117 of said
arms firmly pinch the overlapping plies of the flexible
tube to crimp and lock said plies together into the shape
shown. The pinching action of the jaws 116 and 1~7 is
released as continued rotation of the out feed rollers
27 and 28 drive the spoke 113 out of the nip of the
rollers.
In the space between the lands Lo and Lo is a
circumferential rib 118 which provides an anvil to
prevent buckling of the walls of the corrugated strip
as the lock is formed.
The spacing of the resulting locks about the
periphery of the tube is determined by the spacing of
the arms 113 about the collar 112.
Alternatively, each of the spokes 113 of the
crimping wheel may consist of a single spring arm which
is moved against and crimps the plies of the corrugated
strip from one side only. In such a case, successive
spokes would consist of an arm corresponding to an arm
AYE and an arm corresponding to an arm 113B, so that
successive spokes would be moved against the plies
of the strip from opposite directions.
The curling die is adjustable so that it may
fabricate flexible tube from about 50.8 mm (2 inches) to
about 508 mm (20 inches) in diameter. If a tube to
be fabricated is to have a diameter in the extreme
lower part of this range, then the rollers 29 and 35
must be removed as illustrated in jig. 13.
The bending device 119 comprises a pivoted plate
Lowe which is mounted upon the gear housing 41 coaxial
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with the lower out feed roller 27. A gear segment 120
on the plate Lowe meshes with a worm 121 that is formed
upon a manually rotatable spindle 122. A bending roller
123 is journal Ed upon a spindle on the plate Lowe where
it normally occupies an operative position between the
nip of the indeed rollers 27-28 and the first curling
die roller 29. A bending pin 124 may also be used with
the bending roller 123.
When or not the bending device 119 is used during
a curling operation depends both upon the diameter of
the tube being formed and upon the stiffness of the ma-
tonal in the strip S.
The least expensive of suitable aluminum stock
which is available in the US. market is of the stiff-
news used in the standard aluminum foil trays in which
frozen foods are packaged. That material is stiff
enough that the bending device 119 desirably is used
regardless of the diameter of the tube that is being
formed. The manually rotatable spindle 122 with its worm
121 is used to locate the roller 123 in the proper post-
lion between the rollers 27-28 and the first idler not-
for 29 or 30, as the case may be.
At the present time any aluminum strip which is
softer thanl~that used for freezer trays must be custom
fabricated, and it is thus enormously more expensive.
However, where strip material of about half the hardness
of the freezer tray stock is used, the bending device
119 is required only for the fabrication of tubes smaller
than about 76.2 mm (3 inches); and for larger tubes the
bending attachment may be swung entirely out of the way
; by turning the spindle 122.
As seen in Fig. 13, when a tube of about 50.8 mm
diameter (2 inches) is being formed, the axis of the
bending roller 123 is almost precisely where the axis
of the removed idler roller 129 is located.
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The foregoing detailed description is given
for clearness of understanding only and no unnecessary
limitations should be understood therefrom, as modifica-
lions will be obvious to those skilled in the art.
