Note: Descriptions are shown in the official language in which they were submitted.
~i
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Technical Domain
The present invention relates to a support roller
winder for winding onto cores a web of material that is
divided by one or more longitudinal cuts or slits, and a
procedure to wind webs of material.
Support roller winder machines of this kind are
used for the arborless winding of webs of material that have
been divided by a longitudinal cut, said webs being', in
particular, of paper or cardboard, onto cores, when the
winding rolls lie aligned on the support rollers during the
winding process. Other than in the case of the so-called
on-axle rolling, in which a set of winding rolls are held by
means of an axle that passes through all the cores during
the winding process, in arborless winding, two guide heads
are moved into the cores of the outermost winding rolls from
outside.
Prior Art
Using the support roller winders of this kind, as
are known from DE-A 36 18 955, it is only possible to
produce rolls of the desired winding quality up to a
specific diameter. The reason for this is that the: hardness
of a roll is effected decisively by the line load (i.e., the
contact load per width of a winding roll) on the two
supporting lines of the rolls on the supporting
2~~9~~8
WO 92/03366 3 PCT/EP91/01555
rolls. As far as possible, the winding hardness should be even
for the whole set of winding rolls and around the diameter of
each individual roll and be of a predetermined value which, in
known support roller winders, is exceeded beyond a certain
diameter because of the increasing contact load, and thus
determines the maximal winding roll diameter.
In order to relieve the dead weight in support roller winders
with on-axle rolling, DE-PS 11 11 496 teaches that an over-
pressure can be generated in the area that is defined by the
support rollers and the winding roll. Cover plates, which are
matched to the shape of the support rollers, serve to seal off
the hollow space at the sides, these being moveable so that then
they can be applied to the face sides of the winding rolls.
Sealing off below is effected with a roller or group of rollers
that are tangent to both support rollers. The sealing elements
that are shown in DE-PS 11 11 496 are not suitable for use on
support roller winders with arborless winding because they and
their attachment elements aro located in the area of movement of
the guide heads. Furthermore, a friction connection is generated
between the two support rollers by the sealing roller that lies
against them, and this makes it impossible to adjust various
torsional moments so as to influence the quality of the winding.
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Description of the Invention
It is the task of the invention to create a
support roller winder of this kind, with arborless rolling,
through which winding of rolls of large diameter anal a high
level of winding quality can be produced.
The invention provides a support roller winder for
winding a web of material that is divided by a longitudinal
cut onto cores to form wound rolls, comprising: two support
rollers on which rolls being wound lie during the winding-on
process, said support rollers spaced by a gap; at each end
of said winder a vertically moveable guide head that is
selectively moveable from above downwards into the area of
the upper side of the gap between the support rollers, on
respective ends of the.support rollers, each said guide head
being moveable axially inwards in order to engage the cores
of the two outer rolls; means to seal the space between the
support rollers and the rolls and to generate an over-
pressure therein; sealing elements arranged at opposite ends
of the support rollers seal off at least the cross sectional
area of the upper gap between the two support rollers, said
sealing elements being axially displaceable to accommodate
different web widths; said sealing elements being moveable
to locations outside the area of movement of the associated
guide heads; wherein said sealing means and sealing elements
when in sealing position do not fractionally engage said
support rollers.
The invention also provides a process for winding
webs of material onto cores wherein during the winding
process rolls being wound lie on two supporting rollers and
are held by two lateral guide heads, wherein contact load
with the supporting rollers of the rolls being wound is kept
constant during the winding process, a rising overpressure
a
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being generated in the space defined by the supporting
rollers and the winding rolls being wound by regulated
controlled introduction of compressed air into said space,
this overpressure compensating for the increasing weight of
5 the rolls as they are wound.
The support roller winder according to th.e present
invention incorporates the advantages of an arborless
rolling procedure (no inconvenient manipulation of a heavy
and long shaft, in particular in the case of wide webs; and
rapid roll changeovers) without the maximum wound roll
diameter being restricted by the contact load, to the known
degree. Furthermore, relieving of the over-pressure
constitutes an additional adjustment parameter by means of
which the hardness of the roll can be controlled or
regulated.
The use of compressed air feed from below means,
on the one hand, that the elements used to supply the
compressed air can be arranged beneath the supporting roll,
and, on the other hand, that compressed air can be injected
from below as additional sealing barrier air.
Vertical adjustability of the element that
provides the lower sealing can be effected by means of
raising or pivoting elements. On the one hand, this serves
to remove the sealing element from the support rollers,
e.g., to remove paper scraps after a paper blockage. On the
other hand, it can be adjusted vertically downwards to the
point that the face-side sealing elements that are arranged
on the upper side of the sealing element are no longer
located in the area of movement of the guide heads.
Because of the fact that the lower sealing element
can be pivoted into the area beneath a support roller, free
space is created for a separator blade that can be raised
..
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from below through the support roller gap. Separator blades
of this kind can be used providing the web is fed through
the support roller gap from below.
In an embodiment the face-side sealing elements
can be moved axially out of the area of the support. rollers.
The movement out of the area of the guide heads is effected
either by means of a continued axial movement to the
outside, or by means of an additional lowering movement as
soon as they have left the area of the support rollers.
In other embodiments of the invention the: face-end
sealing elements can be removed from the area of the guide
heads by a pivoting movement. Division entails the:
advantage that less space is required for any particular
pivoting movement. Thus, the sealing elements can be used
even at a small winding diameter, at which the guide heads
are located even lower: i.e., the over-pressure can be
employed at an earlier time in the winding process in order
to effect the quality of said winding.
An embodiment, with round guides attached to the
pivot arms on which the face-end sealing elements are
supported, is advantageous from the structural point of view
and is economical with respect to space. A somewhat
eccentric displacement of the axis of pivot to the axes of
the support rollers and outwards in the form that i.s claimed
means that on being pivoted over one of the supporting
rollers the sealing elements move somewhat away from this.
This means that paper scraps, e.g., after a paper blockage,
can be removed without any problem. When this is done, the
sealing elements are either secured at the inner end of the
round guides which, in this case, are supported in the pivot
arms in such a way that they can be moved outwards, or else
the pivot arms are angled, when the apex of the angles is
n
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located outside the area of the support rollers. Then,
continuous round guides that extend to the whole working
width can be secured to the pivot arms, with the sealing
elements being secured to these so as to be moveable. Thus,
the round guides do not need to be moved out beyond the
support rollers on being adjusted to the maximal web width.
The sealing elements can be provided with
labyrinth seals which makes it possible to seal without any
friction being generated with a winding roll or a support
roller. The compression effect can be increased by feeding
in blocking air.
Embodiments of the sealing surfaces have sealing
elements that achieve a high sealing effect with only a
small amount of friction.
A particularly advantageous embodiment permits
lateral sealing with the smallest possible losses of
compressed air, at various over-pressures. It is possible
to arrive at a balance of forces between the contact
pressure generated by the pneumatic plunger-cylinder unit
and the counterforce from the over-pressure such that a
minimum gap is set automatically between the sealing element
and the face-side of the outer winding roll. In the event
that the gap grows smaller or larger as a result of axial
displacement of the winding roll, the over-pressure will
either increase or decrease so that the increased or reduced
counterforce initiates a correcting movement of the sealing
element.
n
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A pneumatic plunger-cylinder unit serves to
displace the sealing elements simultaneously in a
structurally advantageous manner in order to match them to
different web widths. An additional electrical or hydraulic
drive system may be provided for axial displacement.
The moveable attachment of the pneumatic plunger-
cylinder unit about the axis parallel to the parallel-axis
guide ensures that the sealing elements can move freely on
the guides.
The described procedure used for winding webs of
material as makes it possible to wind up winding rolls of
very large diameter, when regulation or control of the
winding hardness is made considerably simpler because one of
the decisive effecting factors, namely the line load on the
two contact lines between the winding rolls and the support
rollers, no longer changes.
Brief Description of the Drawings
The drawings serve to describe the present
invention on the basis of embodiments that are shown in
simplified form.
2~698~8
WO 92/03366 9 PCT/EP91/01555
Figure 1: a diagrammatic side view of a support roller winder
according to the present invention:
Figure 2, 3: sections of the associated cross section wherein
the axial length of the air box differs;
Figures 4, 5 or 6, 7, respectively: two additional embodiments,
each in side view and plan view, wherein only those
parts that are essential to the present invention are
shown;
Figure 8: a diagrammatic side view of part of the support
roller winder, in which the side sealing elements can
be pressed pneumatically against the outer winding
roll;
Figure 9: a plan view of the winder as in figure 8:
Figure 10: an enlarged section of figure 9.
Constructio~p of the Present Invention
The double support roller winder, of which only those parts that
relate to the present invention are described in detail,
incorporates two support rollers 2, 3 that are supported in the
machine frame 1. The axis of these support rollers are parallel,
are spaced at a small distance from each other, and extend across
the whole working width, i.e., the maximum width of the web 4
that is to be wound. The diameters of the support rollers 2, 3
are either different, in which case the height of the axes of
~p~9898
WO 92/03366 10 PCT/EP91/01555
said rollers are offset somewhat (figures 1 to 3), or the
diameters of these rollers are the same, when the axes of
rotation of said rollers lie in a horizontal plane (figures 4 to
10). A longitudinal cutter 5 divides the web 4 into individual
webs from which the winding rolls 6 are produced; these rolls 6
lie aligned with each other on the two support rollers 2, 3
during the winding process. The web 4 is fed to the winding
point either from below through the support roller gap (figures
1, 4, 8), or from above, when it wraps slightly around one of the
support~rollers (figure 6).
On both sides of the machine, within the frame 1, slides 9 that
can be raised and lowered by means of a plunger-cylinder unit 8
are secured in guides 7 that are almost vertical: these support a
guide head 10 that projects inwards. In order to guide the
winding rolls 6 in an axial direction during the winding process,
each of the two guide heads 10 move inwards into the two outer
cores 11 prior to the start of the winding process, and remain
there until the winding rolls 6 have been wound to completion.
In order that they can be moved into the empty cores 11, and to
ensure accommodation to different web widths, the guide heads 10
are secured to the slides 9 so as to be axially displaceable by
means of a drive system. To this end, the slide 9 supports a
hollow cylinder guide that extends horizontally inwards, and
within which there is a trunnion that is axially displaceable by
means of a spindle, the guide head 10 being secured at the end of
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this [trunnion]. This construction is described in detail in US-
PS 4, 483, 493.
The guides 7 i~un outside the area of the upper gap between the
two support rollers 2, 3 at a distance parallel to the
perpendicular to the connecting line between the two support
roller axes, through the middle of the support roller gap. They
end a little above the connecting line between the two support
roller axes. Thus, the guide heads 10 can move into the cores 11
that lie in the gap between the two support rollers 2, 3. As
soon as the lower edges of the slide 9 together with the cores 11
have moved far enough upwards on the guides 7 as the winding
rolls 6 become larger, there is space available on both sides of
the machine, above the support rollers 2, 3, in order to avoid
collisions with the sealing elements, which are described in
greater detail below.
The machine incorporates a roll ejection beam 12 and a drop stage
13 that accommodate the finished winding rolls 6 and which can be
lowered for purposes of unloading. If the web is fed in from
below, a cutter 14 can be arranged beneath the support rollers 2
and 3 in such a manner as to be moveable upwards through the gap
between the rolls in order to separate the web 4, as is shown in
figure 6 [There is no reference figure 14 shown in figure 6--
Tr.].
2~~989~
WO 92/03366 12 PGT/EP91/01555
In order to reduce the contact weight of the winding roll 6 on
the support roller 2, compressed air can be used to generate an
over-pressure in the space that is defined by the support rollers
2, 3 and the winding roll 6. The following elements, which are
described in greater detail below, are used to do this.
In all of the embodiments that are shown in the drawings, within
the lower gap between the two support rollers 2, 3, there is an
air box 15 with a compressed air feed line, this extending at
least over the area of the minimal width of the web 4 and having
on its upper defining surface, which is proximate to the winding
rolls 6, outlet openings for compressed air. On its underside,
the air box 15 is secured to raising and lowering elements in
order that it can be lowered. Hecause of the fact that beneath
the support rollers 2, 3, there is a cutter 14 that can be moved
upwards through the roller gap, pivot arms 16 are secured to the
air box 15 and these permit a downward pivoting movement to a
point beneath one support roller (support roller 3 in figures 4
and 8), in order to create free space for the blade 14 to move
upwards. Without this sort of blade, the air box 15 is lowered
by means of lifting elements (lifting cylinders 17) (figures 1,
6). The sides of the upper part of the air box 15 that are
proximate to the support rollers 2, 3 are curved so as to match
the surfaces of the supporting rolls 2, 3, such that when they
are in the sealing position, there is only a small gap left open
so as to avoid friction. On their sides that are praximate to
~Ofi989~
WO 92/03366 13 PCT/EP91/01555
the support rollers 2, 3, the side surfaces incorporate a series
of grooves that are parallel to the axes of the support rollers,
and these, running transversely through the direction .of flow of
the outflowing compressed air, act as labyrinth-type seals. The
height of the side surfaces that act as seals is matched to the
sealing performance that is required. On the side of the support
roller 2, that moves inwards into the upper gap, they can be
smaller than on the other side since, because of the direction of
ratation, air that acts against the outflow will be carried along
with the support roller 2 or with the web 4 that is located on
it.
In the embodiments shown in figures 1 to 3, the upper side of the
air box 15 also serves as a guide surface for two face-side
sealing elements 18 that are secured on both sides of the machine
so as to be axially displaceable. In order 'that the sealing
elements can be moved in an axial direction to a point outside
the area of the support rollers 2, the air box 15 extends to a
point beyond the supporting rolls 2, 3 on both sides of the
machine, as is shown in figures 2 and 3. The shape of the face-
side sealing elements 18 is matched to the unobstructed cross
sectional area between the support rollers 2 and 3, with the
upper portion being extended rectangularly to a point above the
connecting line between the two apexes in order to provide an
adequate sealing surface for winding rolls of large diameter. On
the side that is proximate to the winding rolls 6, the extended
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WO 92/03366 14 PCT/EP91/01555
portion incorporates grooves which, acting as labyrinth seals,
bring about a sufficient reduction of compressed air losses.
There are also grooves on the curved sides that are proximate to
the support rollers 2, 3. They also run transversely to the
possible direction of autflow, thus approximately corresponding
to the periphery of the particular adjacent support roller 2, 3.
The sealing elements 18 move laterally next to the guides 7, so
that they can be moved against the face sides of the winding
rolls 6 when, once in the sealing position, a small gap remains
and thus no friction is generated.
In order to provide for axial movement of the support rollers 2
and 3, in each instance displacing elements, e.g., a driveable
spindle (not shown herein), is secured to the outer side of each
sealing element 18. In the embodiment shown in figure 2, the
sealing elements 18 can be moved so far outwards that the slides
9 together with the guide heads 10 can be lowered into the gap
between the two support rollers 2, 3 in order to move into empty
cores 11 that are located there.
In the embodiment shown in figure 3, the air box 15 together with
the sealing elements 18 can be lowered so far that the upper
edges of the sealing elements 18 are located beneath the
narrowest point between the two support rollers 2, 3. Thus, the
air box 15 need only extend a small distance beyond the ends of
the support rallers 2, 3. The axial movement of the sealing
~p6989~
WO 92/03366 15 PCT/EP91/01555
elements 18 at the outermost ends of the aix box 15 then permits
only a subsequent lowering, either by tilting down or a linear
lowering, which then creates the free space that is required for
the slides 9.
Figures 4 to 10 show preferred embodiments of the present
invention in which the face-end sealing elements 18 are moved in
or against the direction of movement of the web, which is to say
out beyond the support rollers 2, 3, out of the lower working
area of the guide heads 10. In this case, it is not necessary
that the air box 15 extend laterally beyond the support rollers
2, 3 and for this reason its length is approximately equal to the
length of the support rollers 2, 3. In order to permit them to
pivot upwards, the sealing elements 18 end at the narrowest point
between the support rollers 2, 3. Accordingly, the air box
reaches from below up to this point. The sealing elements 18 are
connected on both machine sides with pivot arms 19, 20, the pivot
axes 21, 22 of which either coincide with the particular axis of
the support rollers ar extend somewhat eccentrically outwards on
the line of connection between the two support roller axes. This
small eccentricity leads to the fact that the side surfaces of
the sealing elements 18, which are proximate to the support
rollers 2, 3 respectively, move somewhat away from the particular
support roller surface when being pivoted outwards so that, for
example, scraps of paper can be removed. In the event that it is
necessary to move the sealing elements 18 even further away from
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WO 92/03366 16 PCT/EP91/01555
the support rollers, they are secured to double levers. In the
embodiments shown in figures 4 to 7, too, the sides of the
sealing elements 18 that are proximate to the support rollers 2
and 3 and of the air box 15 are provided with labyrinth-type
seals such as have been described heretofore.
In the embodiments shown in figures 4 to 5, the arms 19 that can
pivot about the runout-side support roller 3 support on each
machine side a one-piece sealing element 18. To this end, the
arms 23 are angled at their ends so that when in the inward
pivoted position they extend approximately horizontally between
the support rollers 2, 3. On each angled end of the two pivot
arms 19, there are two round guides 23 that are supported so as
to be axially displaceable, and the sealing elements 18 are
secured to the inner ends of these. In the embodiment shown in
figures 6 and 7, each face-side sealing element 18 is divided
along the perpendicular through the middle of the support roller
gap. Each of the parts 24, 25 is secured to a pivot arm 19, 20
that can be pivoted over the adjacent support roller 2, 3. As is
shown in figure 6, the pivoting movement thus requires less
space, so that the sealing element 18 can be used at an earlier
time.
Tn the embodiment shown in figures 8 and 10, too, the sealing
elements 18 are supported so as to be axially moveable--which is
to say transversely to the web 4--on arms 19 that can pivot about
r~D:~9898
WO 92/03366 17 PCT/EP91/01555
the support roller 3 on the runout side. In this way, they can
be pivoted out of the lower working area of the guide heads 10
(indicated by the dashed line in figure 8) by pivoting over the
support roller 3. The pivot arms 19 are angled at their
unattached ends so that when pivoted inwards these extend
approximately horizontal between the support rollers 2, 3. Their
axis of pivot 25 extends, displace somewhat eccentrically
outwards, on the connecting line between the two support roller
axes. The slight eccentricity leads to the fact that the side
surfaces of the sealing elements 18 that are proximate to the
support roller 2 or 3, respectively, move somewhat away from the
particular support roller surface when being pivoted outwards so
that, for example, paper scraps can be removed. At the angled
ends of each of the two pivot arms 19 there are two round guides
23, these being supported so as to be axially displaceable, and
sealing elements 18 are attached to the inner ends of these. The
plunger 26 of a pneumatic plunger-cylinder unit is secured to the
upper side of the pivot arm 19 in order to effect the axial
displacement of the sealing elements 18 and permit them to be
pressed against the face sides of the outer winding rolls 6. The
end of the plunger rod 27 is supported on the sealing element 18
so as to be moveable about both axes perpendicular to the guides
23. To this end, a spindle 28 is secured to the upper side of
each sealing element 18 and this passes through the eye of the
plunger rod 27. The pneumatic plunger-cylinder unit 26, 27 is
connected to a control system (not shown herein) to permit the
2p~~898
WO 92/03366 18 PCT/~P91/01555
axial displacement of the sealing element 18 and to sit an
adjustable contact pressure.
In the preceding embodiments, the plunger-cylinder unit 26, 27
displaces the sealing elements 18 axially to match them to
different web widths, and to press them against the winding rolls
6. In the same way, it is also possible to have both these tasks
carried out by separate drive systems. Then, an electrical or
hydraulic drive system is secured to the pivot arms 19 to effect
this axial displacement, and this is connected through the
pneumatic plunger-cylinder units 26, 27 to the sealing elements
18.
Tn an embodiment of the present invention that is not shown
herein, the pivot arms that support the sealing elements 18 are
angled, when the apex of the angle is located outside the area of
the support rollers 2, 3. The ends of guides that extend to the
whole length of the support rollers 2, 3 are secured to the apex
points of the angles and the sealing elements 18 are movably
supported on these guides. This means that the guides are no
longer displaced in an axial direction in order to permit
adjustment to different web widths.
Once new cores 11 have been installed in the support roller bed
from above, the guide heads 10 are moved in. After the start of
CA 02069898 2002-04-16
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19
the web 4 has been secured to the cores and the pressure roll 26
has been moved into position, the winding process begins.
As long as the installed weight of the winding roll 6 is not
sufficient to achieve the desired degree of hardness in the
winding rolls, the pressure roll 26 is additionally pressed in
the direction of the support rollers 2, 3. As soon as the
contact load becomes too great, an over-pressure is generated in
the space that is defined by the support rollers~2, 3 and the
winding roll 6, and this then reduces the contact load. At this
time, the winding roll 6 will already be of a sufficiently large
diameter (approximately 800 mm), so that their cores. 11, and
thus the slides 9 are at a sufficient distance above: the support
rollers 2 and 3 to\avoid a collision with the sealing elements
18. In order to seal off the space that is defined by the
winding rolls 6 and the support rollers 2, 3, the ai.r box 15 is
first moved into the lower gap between the support rollers 2 and
3 so that the side surfaces of the air box 15 lie against the
support rollers 2 and 3 so as to leave a narrow gap and thus seal
it off from below. Then, the face-side sealing elements 18 are
moved upwards and inwards until only a small gap is left between
them and the face sides of the winding roll 6, so that these
sides are also sealed off. Now, compressed air is .introduced
through the air box 15 until such a high pressure i:a built up
beneath the winding roll 6 that the contact load of the winding
roll 6 is reduced to the extent that is desired.
X069898
TAO 92/03366 20 PCT/EP91/01555
In the embodiment shawn in figures 8 to l0, compressed air is
first introduced through the air box 15 that has been pivoted
upwards and then the sealing elements 18 are moved axially
against the face sides of the winding roll 6 by means of the
plunger-cylinder units 26, 27. The pressure in the plunger 26 is
so controlled that as the over-pressure builds up a force
equilibrium is set up in such a way that a small gap remains
between the sealing elements 18 and the winding roll 6. Thus,
friction at minimal compressed air losses is avoided. In the
event that the width of the gap grows larger or smaller, e.g.,
because of an axial displacement of the winding roll 6, the
pressure beneath the winding roll 6 will fall or rise because of
the increased or reduced losses of compressed air. The resulting
pressure differential relative to the pressure in the pneumatic
plunger-cylinder unit 26, 27 automatically leads to a correction
of the width of the gap until such time as the force equilibrium
has been re-established. As an alternative, a smaller gap can be
maintained between the sealing elements 18 and the winding roll 6
such that a smaller distance is set automatically to the position
of the guide heads 10.
It is preferred that the contact load of the winding roll 6 be
kept constant during the winding process. To this end, after the
desired contact load, a control or regulating system sets the
over-pressure beneath the winding roll 6 such that compensation
is constantly made for the increased weight. The regulation or
2069898
WO 92/03366 21 PCT/~P91/01555
control of the winding hardness is greatly simplified: by this,
since one of the decisive influential factors, namely, the line
load on the two contact lines between the winding roll 6 and the
support rollers 2 and 3 no longer changes.
Alternatively, the reduction of the contact load can also be
effected incrementally by building up an appropriate over-
pressure in order to keep the contact load within a specified
range. In the same way, the increase in the contact load can be
compensated for only in part or it can be reduced according to a
given function. Under some circumstances, a one-time reduction
by a constant value will be sufficient. In each case, building
up an over-pressure provides yet another parameter to control the
wound hardness of the winding roll 6.
In the embodiment shown in figures 8 to 10, the pressure in the
pneumatic plunger-cylinder units 26, 27 is increased by the
regulating system in keeping with the growing over-pressure, in
order that the distance between the sealing elements 18 and the
winding roll 6 remains constant.
In place of the labyrinth seals on the sealing surfaces, both in
the upper gap and in the lower gap between the support rollers 2,
3, it is possible to seal the outlet openings for compressed air
with blocking air. In the same way, the sealing effect achieved
by the labyrinth seals can be enhanced by feeding blocking air
2~~9898
WO 92/03366 22 PCT/EP91/01555
into the grooves of these labyrinth seals. If the support
rollers 2, 3 are arranged very close together, it may be
sufficient to inject compressed air through the narrowest point
by means of a slot nozzle. The compressed air that is injected
from below then works simultaneausly as blocking air in order to
reduce losses through the narrow gap between the support rollers
2, 3.
In the same way, it is also possible to use sealing elements such
as brushes, rubber lip seals, felt overlays, and the like,
providing that the friction between the support rollers 2 and 3
and the winding roll 6 can be kept sufficiently low, either
because of the fact that the sealing elements rest with very
little friction on the winding roll 6 and the support rollers 2,
3 or are positioned from these at such a small distance that
losses of compressed air are acceptably low. When sealing, it is
also important that the sealing elements do not restrict the
rotational movement of the two support rollers 2, 3 independently
of each other, and in particular that there is no frictional
connection between the two support rollers 2, 3. In other cases,
the different torsional moments of the support rollers 2, 3,
which are required to effect the quality of the winding, cannot
be controlled to the required degree.
