Note: Descriptions are shown in the official language in which they were submitted.
X~29S85 D-54 5
CORELESS SURFACE WINDER AND METHOD
.~
:.. This application is a continuation-in-part of co-pending
application Serial No. 08/108,105 filed August 16, 1993 and of
* Serial No. 08/019,074 filed February 18, 1993.
:~,
~CKGROUND AND SUMMARY OF INVENTION: -
This invention relates to a coreless surface winder and
method and, more particularly to a winder that does not use a
~10 core or mandrel but which produces a solid roll, i.e., there is
no hoie in the center with the resulting retail-siz~ roll being
3 "coreless". A~ such, the product i~ considered "environmentally
~ friendly" in that there is less packaging material re~uired and
: no core to dispose of.
Surface winders operate on the exterior of the paper
being wound into a log and usually employ a three drum or roller
. cradle for this purpose -- see, ~or example, co-owned Patent
. 4,848,1~5.
.
,~ * See Cdn. App. 2 ,102, 938 filed November 12, 1993 .
- 1 -
~y
Z~2958S
- The three drums usually include first and second winding
drums and a pivotally mounted rider drum. Historically, a core
'~ i5 introduced into the nip between the two winding drums where itbecomes enveloped with the web being wound -- with the wind being
completed when the incipient log is cradled among the three
J drums. The log generally is of a length to provide a plurality
of retail size rolls -- each being about 4" (100 mm) to 5" (125
.:
mm) length. These logs are continuously wound at high speed
generally 2500-3000 fpm (750-900 mpm) resulting in 20-30 logs per
minute having axial lengths of from about 100" (3m) to about 200"
(6m)-
~ The improvement of this invention over the earlier filed
,3 curved plate innovation in Serial No. 08/108,105 is the drum to
drum transfer which keeps the incipient log product parallel to
the drums. This minimizes the wrinkling and tension problem. In
" j .
,~ coreless surface winding the product is folded over itself to
initiate the rolling start of wind. The drum-to-drum initiat~d
'~ start of wind provides instantaneous acceleration into rotational, speed, which is contained in the parallel nip. This is in
contrast to the drum and curved plate method start of wind where
the incipient roll is accelerated into one-half rotational speed
and one-half linear speed, which tends to move non-parallel to
the nip due to the inconsistencie~ in web material and diameter
buildup.
The instant invention makes use of a pair of windin~
~` drums located in close proximi~y to each other and where one drum
- 2 -
!~
:~.'',,
. ,,
:
21295~5
--~is equipped with a slot for cutoff and means rearward of the slot
for carrying the severed web toward the nip between the two drums
where winding begins. More particularly, the severed web is
folded on itself along a line defined by the carrying means. The
nip or distance between the two winding drums is advantageously a
function of the thickness of the web material, being less than
twice the thickness of the web material. Where the web is wound
; "downstream" of the nip a minimum nip of one web thickness is
required to allow the end tail of the finished roll to go through
the nip. Where the web is wound upstream of the nip, the nip
spacing can be minimal.
; According to the invention, there is no core and the
wind is started by a rubbing motion brought about by introducing
a folded leading edge of a severed web toward the controlled nip
area between the two winding drums. At the speeds involved, it
~, i8 only a fraction of a second for the leading edge to form an
incipient roll or log and then travel into the conventional three
i dru~ surface winder cradle. As ~he leading edge of the severed
web enters the nip area, both winding drums are rotating in the
same direction -- counterclockwise, for example.
The phenomenon o~ a reverse folded leading edge is
illustrated in detail in co-owned patent RE 28,353. There, a
portion of the web rearward of a severed leading edge is
immobilized against the surface of a bedroll. When that occurs,
~ 25 windage and centrifugal force curl the leading edge on itself
;1 back to the immobilizing means which may be vac~um, pins, etc.
'`' 1 -
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X~L29585
~ In the '353 patent at transfer, pushers engaged the folded
leading edge against the glue-equipped cores. An advantage of
the folded web, as described in the '353 patent, is the
entrapment of one ply within the other when two ply tissue is
being wound. If the leading edge were not controlled, it could
l fly away under the influence to the above mentioned factors:
windage and centrifugal force -- and stop the winding.
The advantage of the folded web in the instant invention
~, i5 to increase to at least two thicknesses (and with its usualwidth) to cause the leading edge of the web to roll back onto
, itself, across the width as it enters the nip area. So, it is
~, clear that the operation of prior art winders is completely
J different from that of the instant invention. Hence, another
advantageous use of the reversely folded leading edge portion has
been found so as to ~e able to start a surface wind and thereby
provide solid log.
The invention also includes means for negating or
limiting uncontrolled movement of the incipient log away from the
nip upon increase of the contact angle of a incipient log --
which stems from increase in incipient log diameter. In the
illustrated embodiments, this means takes the form of (a) means
for the moving winding drums as by moving one drum away from
another which is espeicially advantageous for relatively slow
speeds and/or (b) finger means for applying pressure to the
incipient log.
The contact angle referred to is the angle included
- 4 -
,.
.
585
.,
-between lines connecting the point in the middle of the nip with
the points of tangency made by the contact of the winding drums
with the incipient log. The precise location of the tangency or
contact points can vary somewhat depending upon the
compressibility of the web making up the incipient log and the
:i'
geometry of the system.
The invention further includes a means and method for
, minimizing slippage in a solid-wound roll. Slippage has been
-~ known and tolerated for a long time -- see Patent No. 1,719,830.
Thei minimizing of slippage between the web being wound and use of
the winding drums includes providing one of the drum~ with a
unique speed profile. Further details of the speed profile in a
, core-type winder can be seen in my co-pending application Serial
:'i
* No. 08/019,074 filed February 18, 1993, now Patent No.
~15 There, in a similar ~urface winder but operating on a series of
3~ cores, I provided control means for changing the rotational speed
of the lower winding drum to substantially eliminate slippage
j~ between the lower winding drum and a we~ roll being wound on a
core. This consisted of providing a speed profile in the lower
winding drum wherein the speed of the lower winding drum is
decreased just prior to the beginning of each winding cycle to
advance a partially wound roll toward and through the windinq
drum nip and thereafter increasing the speed of the lower windlng
~ drum a~ a function of the increasing diameter of a partially
'~25 wound roll.
This invention further makes available an advantag~ou~
.~
,.
* See Cdn App. 2,102,938 filed November 12, 1993
"'3
.
2~29585
-- taper winding, i.e., portions of rolls being gradually harder or
softer than other portions -- by virtue of modifying the speed
profile. Further details of and other advantages applicable to
i both core and coreless wound rolls can be seen in my co-pending
application Serial No. , filed and
reference may be had thereto for additional details not found
herein.
The previously mentioned movement of one winding drum is
5~l especially advantageous in this connection by being moved through
l 10 a closed orbit. Still further, the slippage between one winding
drum and the web being wound resulting from advancement of the
web central portion, viz., the folded over portion and its
consequent buildup into an incipient log, is advantageously
minimized by changing the operation of the rider roll -- either
by giving it a speed profile or by moving it through a closed
loop or both. This is done by giving the rider drum an speed
profiie somewhat similar to that of one of the winding drums --
and also, cumulatively or alternatively, moving it through a
closed loop each cycle.
Other object5, advantages and details of the instant
invention may be seen in the ensuing specification.
BRIEF DESCRIPTION OF DRAWING:
The invention is described in conjunction with the
accompanying drawing, in which --
FIG. 1 is a side elevational view, somewhat schematic,
of a winder embodying features of the invention;
- 6 -
;:~
.~
X1295~35
. - FIG. 2 is an end el~vational view of the winder of FIG.
1 in what might be considered a ~developed" view, i.e., the
various drums being spread apart so as to better illustrate their
arrangement;
FIG. 3 is an enlarged fragmentary view of a portion of
FIG. 1 and shows the cutoff of a web which signals the beginning
of the winding of a new log according to the invention;
FIGS. 4-6 are views essentially similar to FIG. 3 but
~ depicting the winding in subsequent stages thereof; for example
¦ 10 FIG. 4 shows the development of the reverse fold on the leading
edge portion of the transversely severed web as can be
appreciated from the fact that the upper winding drum has rotated
~, from having the cutoff slot at the twelve o'clock position to
about a 10:30 position;
FIG. 5 is another fragmentary view like FIG. 4 and shows
the cutoff slot at about a 6:30 position;
FIG. 6 shows the slot at about a 5:00 o'clock position
and where the folded leading edge is entering the nip area
between the two winding drums;
FIG. 7A is an enlarged fragmentary ~ide elevational view
showing the completed log in the three drum cradle and the newly
severed web in its initial stage of winding while FIG. 7B is an
enlarged fragmentary view of the central portion of FIG. 7A and
illu~trates the contact angle resulting from movement of the
incipient log away from the nip;
FIG. 8 is a view similar to FIG. 7 but slightly later in
- 7 -
~;,
. ., .~
Z9 29S8~ ~
~he winding process while FIG. 8A is a graph of the speed profile
or curve developed in one of the winding rolls for minimizing
slippage and flanking that are curves showing speed profiles for
tighter (upper) and looser (lower) winds;
FIGS. 9A-D are enlarged fragmentary side elevational
views of the web being folded on itself and being wound into an
~i incipient log;
, FIGS. lOA-G are a sequence of fragmentary side
3, elevational views showing the effect of orbiting the lower
~ 10 winding roll in minimizing slippage the chart showing the
;¦ di~erence in speed profiles is illustrated in FIG. lOH, and a
schematic size elevational view of a two-bar mechanism for
, orbiting the lower winding roll is depicted in FIG. lOI;
FIG. 11 i~ a side elevational somewhat schematic and
~imilar to FIG. 8 which illustrates the closed loop or orbit
, operation of the rider drum providing further advantageous
, operation of the inventive winder.
FIG. 12 i8 a side elevational view similar to FIG. 8 but
i' of another embodiment of the invention and FIG 12A is a view
, 20 similar to FIG. 8A but of the FIG. 12 embodiment.
FIG. 13A i8 a view similar to FIG. 12 but slightly later
in thQ winding process while 13B i~ an enlargement of a central
portion o~ FIG. 13A; and
,,
FIGS. 14A-D are views similar to FIGS. llA-D but of an
~ 25 alternative way o~ starting the wind.
'~1
~ - 8 -
2~95~5
': :
: PETAILED DESCRIPTION:
In FIG. 1, the numeral 20 designates generally a frame
which is shown fragmentarily but which includes the usual side
~rames 20a and 20b -- see FIG. 2. Additional details may be seen
in co-owned Patent RE 28,353. The frame 20 rotatably carries a
bedroll-type drum 21 which is in the path of travel P of the web
W -- see the central left of Fig. 1.
t~ The web W in traveling within the frame 20 toward
becoming convollltely wound log L travels with a knife drum 22
before engaging the drum 21. The knife drum 22 i5 equipped with
an emergent knife means 23 for transversely severing the web W so
as to terminate one winding cycle and start another.
The winding drum 21 is one of two winding drums for
surface winding -- being accompanied by a second winding drum 24
-- lower as shown. ~ompleting the three drum cradle
`¦ conventionally employed in surface winding is a rider drum 25
which is supported on an arm 26 pivotally mounted on the frame as
~ at 27. When the log L is completed it is carried by an inclined
,; table sr ramp 28 for further processing as by a takeaway conveyor
, 20 29 -- see the bottom of FIG. 2. The takeaway conveyor 29 moves
:
the logs L transversely of the path followed by the web W and
usually into a log saw (not shown). At the saw, the log is
severed into retail ~ize lengths and thereafter packaged. The
~', three drum cradle and accompanying elements thus far described
are generally conventional.
'~ ~ g _
~ .
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Z~29585
` The First Embodiment as seen in FIGS. 3-6
The initial stages of the invention can be appreciated
from a consideration of FIGS. 3-6 with FIG. 3 illustrating the
cutoff wherein the knife means 23 of the knife drum 22 is
actuated as by a cam 30 so as to cause the knife element 31 to
enter the slot 32 in the upper winding drum 21.
In FIG. 4, there is seen a web carrying means 33 --
illustrated as a vacuum port and which is located a spaced
distance rearwardly (in the direction of drum rotation) of the
slot 32 in drum ~ he web carrying means 33 includes a
transversely extending series of vacuum ports -- see FIG. 2 in
the upper central portion thereof. This results in the
development of a reverse fold as at RF in the upper portion of
FIG. 4.
i 15 In FIG. 5, as the drum 21 continues its rotation --
counterclockwise as shown -- the leading edge E developed by the
reverse fold RF is still aligned with the vacuum port 33 and is
approaching the nip 34 that exists between the drums 21, 24.
In FIG. 6, the orientation of the drums 21, 24 is
slightly later than the showing in ~'ig.5 but still in the
beginning of the wind. The leading edge E is now in the nip area
34 and about to curl on itsel~ -- as will be explained in
con~unction with FIG. 7A.
As Further Seen in FIGS. 7-9
In FIG. 7A, the machine elements and incipient 1O9
product are at a stage slightly later than that depicted in FIC.
. - 10 -
,
`~,
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.~
,~5
. .:i:.. : ~: . : . - : ~
2~295~5
-;. In real time, this is a matter of a fraction of a second.
The actual speed is a substantial factor when the invention makes
use of a movable lower or second winding drum 24. In FIG. 7A
this pivotal movement capability is indicated schematically by a
pivot arm 35 which is pivotally mounted on the frame as 3sa~ A
controller 36 (see the upper right in FIG. 1) regulates the
' movement and speed of drum 24 as other timed members, YiZ., knife cam 30, etc.
The surfaces of the upper and lower winding drum 21, 24
advantageously have a coefficient of friction great enough to
;¦ drive the incipient log product (i.e., roll the log product on
itself) when the folded leading edge E is introduced into the nip
area 34. This can be done a variety of surface finishes for the
J
drums 21, 24. For example, the surfaces may be matte finished,
they may have an entire covering of with a sand paper type finish
or a high friction urethane or rubber covering. Circumferential
bands of the friction material also achieve the advantageous
friction surfaces -- see the schematic band showing 24a in FIG.
2-
~i~, 20 The transfer sequence views o~ FIGS. 7A and 8 show the
l start of wind where the product begins to roll over on itself.
;~ It ha~ been found that surface speeds of the drums 21, 24 of near
~ matched speed work well at the start of wind. As the product
,i builds in diameter, to approximately 0.25 inches (6 mm) it is
.; ~
held in the nip 34 of the two drums by the friction of ~he
`~ growing diameter. After approximately 0.25 inch diameter is
.~
.~
~12958s
~reached the diverging or contact angle is increasing so as to
move the product out of the nip 34, thereby reducing the grip of
the product in the nip. The actual diameter before the friction
; grip is lost is a function of the drum diameters, -- the larger
the drum diameter the larger the product diameter can be before
the contact angle reduces the friction hold. The drum friction
surface also determines the roll diameter where grip lessens
i substantially.
! The increase in the contact angle is illustrated in FIG.
7B. At a small diameter of incipient log IL, the contact angle
is small as at 37 while the larger diameter incipient log IL' has
a larger contact angle 37'.
At the lower speeds it is possible in the initial period
of the wind to avoid the reduction of friction hold stemming from
contact angle increase by opening the gap between the two drums
and, by speed-change of the lower drum, move the product center,
i.e., through the nip. This keeps a grip on the incipient log
until it reaches a diameter where the rider drum 25 can make
contact. At higher speeds however, it is dynamically difficult
to move the winding drums apart fast enough to keep the product
in the nip only by friction. In this case, friction ~ingers 38
are used to create a forward force, i.e., a force directing the
incipient log downstream so as to keep the product moving toward
the nip until the lower drum 24 can be moved away from the upper
drum 21 to advance the product. The force from the fingers 38 is
developed by their being close to the lower drum 24 so that the
- 12 -
~.. ,. .. . . - .
~ 2~Z9S85
-oduct would not be pinched between the fingers 38 and the drum
, ,
24. This is ensured by positioning the pivot arm 38a on the axis
of the drum 24.
The fingers 38 are pivotally mounted on arms 38a which
may be resiliently carried, i.e., spring loaded as at 24b, on the
shaft 39 of the lower drum 24 -- see FIG 2. In FIG. 8, the
-; fingers 38 have pivoted slightly counterclockwise to accommodate
the larger log IL~ and the lower drum 24 has also pivoted
slightly counterclockwise to enlarge the nip to 34' (see FIG. 8).
., .~
, 10 So, if time is available to open the gap between the
i drums 21, 24, or change the speed of one drum, or a combination
l of both, no friction fingers are required. As speeds increase
; and it becomes dynamically difficult to move the drums apart,
¦ fingers work well to drive the product into the nip. Once the
drums have separated, the product can be moved over center via
speed change of the lower drum. Then, the remainder of the
l product can be wound using the "speed profile" of copending
3 * application Serial No. 08/119,074, filed February 18, 1993, now
, ,
~ j Patent No. , and while it is in contact with the
,:
rider drum 25 -- see FIG 8A.
~; The controller 36 changes the rotational speed of drum
24 to substantially eliminate slippage between the second winding
, ~,
i 24 drum and a web log being wound and also provide a speed
profile in the second winding drum wherein the speed of the
second winding drum is near match speed at the start of the wind,
!'~ then decreased quickly after the beginning of each wind cycle to
i~
- 13 -
See Cd~ App. 2,102,938 filed November 12, 1993.
. ,~
h~ i
~2~s85
`~dvanca a partially wound log toward and though the nip 34 and
; thereafter increased as a function of the increasing diameter of
the partially wound log. This can be appreciated from a
consideration of the curve 40 in FIG. 8A.
S~eed Profile and Modifications
"~j
; In FIG. 8A, it will first be noted that the numeral 41
! designates the flat speed profile of the upper winding drum 21.
The numeral 40 designates the speed profile of the lower winding
¦ drum 21. For example, the lower drum speed 40 decreases fairly
rapidly over the initial part of the wind as at 44 so as propel
¦ the now partially wound roll through the nip space 34' (FIG. 8).
Thereafter, the speed of the second winding drum increases
following a path designated 42 and 43 which approaches but does
1 not precisely equal the surface speed of the first winding drum
¦ 15 21. However, at cut-off and the start of a new cycle of winding,
~j I find it advantageous to have a match between the upper and
j lower drum speeds. As the incipient coreless log passes through
the nip, the speed is advanced as at 45. Some variation in speed
,.~
is permissible -- and even advantageous -- depending upon the
geometry of the system and the product being processed.
:
This is particularly true when a taper wind is desired,
; i.e., the hardness or softness changes in proceeding away from
, . .
the roll interior. The lower curve 40 " o~ the group of three
lower curves illustrates a taper wind which is looser or of lower
tension at the start of the wind. This stems from the fact that
the product moves out of the nip 34~ a little earlier than it
; - 14 -
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:. 'J
`:~..,!
" .';
' ' `' ~' , .: ' 'i '` " '
- 21;;~9585
loes when the lower winding roll is operating under the
conditions of curve 40. This results in less compression and a
softer wind, viz., less tension. This is advantageous in
avoiding telescoping during the wind. Telescoping is where the
center or "core" area tends to move axially -- like an open
telescope. With the softer wind at the beginning of the cycle,
the product diameter would tend to get larger. To get a
prescribed diameter, a tighter wind toward the end of the cycle
is employed.
Conversely the upper curve 40' is of a taper wind that
~, i8 tighter at the start and looser at the end. The tighter windstems from the fact that the incipient log stays longer in the
nip area, therefore, the tighter wind. The speed of log movement
., i8 dependent on the speed difference between the two drums 21,
24. The closer the speed is to a match, the slower the movement
of the incipient log and the tighter the wind.
The showing in FIG. 8 is merely illustrative of what can
be two variations from the previously described speed profile
based upon being a function of the increasing diameter of the 1Og
being wound. ~y suitable variation of the speed signal emanating
from the controller 36, it is possible to localize the different
"taper" in any position o~ the cycle, i.e., any annular portion,
as desired and the taper may be either "softer" or "harder" than
the remainder or even an adjacent annulus of the completed 1O9
For example, the tighter wind at the start of the cyc~ e,
viz., curve 40', is advantageous in providing more strength I n
- 15 -
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2~29585
he central area. This is an area of potential deflection during
log sawing. A little more firmness internally supports the
incipient log and the cutting or sawing operation is less
traumatic to it.
After passage of the incipient log through the nip 34',
, the fingers 38 may be moved to their FIG. 7A position to be ready
-¦ for the next log. And during the initial stages of the nextwind, the fingers are pivoted toward the nip as seen in FIG. 8.
Of additional note, it may be advantageous for the
cutoff slot 32 in the drum 21 to contain a resilient material to
~f fill in the slot gap. On the first revolution after the start of
the wind, the slot returns to the small diameter wound product
and a loss of nip contact can create slippage, or the slot could
even carry the small product through the nip. Besides being a
resilient material, the filler could be a mechanical means to
solidly close the gap. This is illustrated as at 46 in FIG. 9A.
The succeeding views 9B-9D show the development of the
log IL' in somewhat exaggerated form of thicker web material but
illustrate the principle of the invention.
Orbiting Lower Windina Drum
Referring to FIGS. lOA-G, the numeral 21 once again
designates the upper winding drum while the numeral 24 designates
the lower winding drum. This particular ss~uence of views
demonstrates how the orbiting or closed path loop of movement of
the lower winding drum can be used to achieve substantial
elimination of slippage between the web being wound and the lower
winding drum but without employing a speed profile of the nature
- 16 -
.
,~.,
2129585
?reviously described in conjunction with FIG. 8. In fact, the
speed profile of the lower drum is a constant as can be
appreciated from FIG. lOH where this is designated 41' in
contrast to the speed profile of the upper drum which is
designated 41. In other words, there is no variation of the
speed of the lower winding drum 24 throughout a given cycle.
The effect of this in combination with the orbiting of
the lower winding roll 24 as illustrated in FIGS. lOA-G is to
provide a result equivalent to that developed by speed profiling
the lower winding roll. For example, at the beginning of the
cycle, which is designated oo in FIG. lOA, it is seen that the
incipient log Lo is behind the dot-dash line D connecting the
centers of the upper and lower winding drums.
j As we progress through the positions it will be noted
that the newly wound incipient log is moving slowly to the right
while the lower winding drum 24 is orbiting in a closed loop
rapidly clockwise. The movement is in a generally illeptical
path but for reasons of simplicity, this is shown as a circle.
The movement can be appreciated from the sequence
wherein FIG. lOB there has been a relatively small movement to
the right of the log Ll while the lower winding roll 17 has
~ moved through 25 of the winding cycle. Then in FIG. lOC, there
`;~ is again a relatively small movement of the log to the position
~ L2 while the lower winding roll 24 has moved through 50 of the
ij
winding cycle. In FIG. lOD, the log L3 has moved again slowly
toward the right whereas the drum 17 has moved through 125 of
the winding cycle. In similar fashion the log is seen to
progress more rapidly to the right as the winding drum 24
proceeds through the remainder of its orbit -- with its dru.
- 17
2129S85
enter having moved to positions of 200, 275O and 325O of the
winding cycle in FIGS. 10E, 10F and 10G, respectively. Thus,
; this profiled movement of the lower drum provides an opportunity
to use a linear speed differential between the upper and lo~wer
winding drums 21, 24, respectively as shown in FIG. 10I at 41,
f 46', respectively.
The means for achieving this operation so as to develop
an advantageous alternative to the speed profile or an
advantageous addition to the speed profile, i.e., the speed
profile and the orbiting lower winding roll in combination, is
; illustrated schematically in FIG. 10I.
~, Now referring to FIG. 10I, the lower winding drum is
; again designated 24 and is mounted for movement relative to both
horizontal and vertical axes X, Y so as to move through the orbit
of FIGS. 10A-G. A variety of linkages can be employed for doing
~ this,.one simple linkage being a two bar linkage including arms3 47, 48. The arm 47 is pivoted on the frame F at 49 and pivotably
interconnected with the arm 48 at 50. The other end of the arm
48 is pivotly interconnected with the bearings 51 supporting the
journals of the drum 24. Suitable actuators such as fluid
pressure cylinders may be employed for moving the arms 47, 48 and
thus tha bearings 51.
The operation of the fluid pressure cylinders (not
shown) is advantageously achieved through the use of a controller
26 as was previously pointed out relative to FIG. 1.
! Orbiting Rider Drum
.1 Referring to FIG. 11, the usual three drum cradle is
- 18 -
~3
:
2~29S85
~ llustrated with the upper and lower winding drums being
designated 21 and 24, respectively. The rider roll 25 which has
also been previously shown in FIG. 1 is seen to be in a variety
of positions. The solid line position designated 25 is the
S position the rider drum occupies at the end of the winding cycle
and just prior to the log Lf starting its descent along the
inclined plane or ramp 28.
The rider drum 25 is supported on a linkage mechanism
operative to provide two degrees of freedom or movement as along
both X and Y axes much the same as was illustrated in FIG. lOI
relative to orbiting or elliptical movement of the lower winding
,.,
drum 24. Here the orbit of the drum center is more in the nature
of a spherical triangle shown in dotted line and generally
designated 52. One leg 53 of the triangle 52 is seen to be
lS somewhat arcuate stemming from the fact that the rider drum
follows the contour of the log Lf. Thus, the log 53 is convex, ~ -
i.e., outwardly arcuate relative to the exterior of triangle 52.
The second leg S4 is shown as a straight line based on
the fact that the drums 21, 24 are of identical diameters. When -~
this is the case, the center of the log moves in a straight line
to the position 25'.
However, in most cases, the diameters are different --
with the lower winding drum having the smaller diameter as shown
in FIG. 1. In such a case, the log follows the lower drum and
the log center therefore moves along an arcuate path. So also
~; does the rider drum to press agains~ the log along a line passing
- 19 -
2129585
~:hrough the log center. Therefore, the rider drum 25 (and its
center) moves along an arcuate path which is concave -- viewed
relative to the interior of the spherical triangle 52.
The third side 55 of the generally spherical triangle 52
is also arcuate, i.e., outwardly convex, and represents a fairly
xapid movement following the contour of the upper winding drum 21
and the exterior contour of the final log Lf - reaching into
tangency with the beginning log Lo~
The advantage of this system illustrated in FIG. 11 is
' 10 the ability to contain the product within an approximately
equilateral triangle between ~he upper and lower drums and the
, riding drum. Even though this has been the goal of previous
three-drum cradles, typically done with a single pivoting arcuate
movement, it has been achieved imperfectly because the single
arcuate path departs substantially from the generally equilateral
triangle made possible by practice of the invention of the
embodiment of FIG. 11. For example, during the segment
designated 54, the invention provides the best containment angle
for stability of wind. At the end of the segment 54 and duri nq
the segment 53 it is advantageous to provide for discharge of the
product by having the rider roll move out of a containment
position relative to the almost completed log. Thereafter, the
¦ return is expeditious because of the unique geometry provided by
this embodiment of the invention. Thus, this embodiment features
a rider drum that has its center moving through a spherical
triangle with generally two arcuate sides. It also may be
advantageous to provide a speed profile to the rider drum 2
- 20 -
,
-.
Z129~85
The rider drum profile is different from that of the
lower winding drum because of the different location and
function. The rider drum 25 runs faster at the end of the cycle
to insure removal of the roll product, i.e., the log L.
,:
Thereafter, the rider drum has a differently positioned profile
;- because it is at a different distance ~rom the upper winding drum
''J 21 than the lower winding drum 24. After log ejection, the speed
is returned to below the web speed and, thereafter, increased as
a function of the increasing diameter of the log being wound.
Second Embodiment --See FIGS. 12-13
A second or alternative embodiment is available where
the distance between the upper and lower drums 121, 12 4 does not
,................ .
change, i.e., no movable winding drum. In this construction,
friction fingers 138 are supported from the downstream side of
l 15 the nip. The upstream side of the nip 134 between the winding
:! drums 121, 124 is the side on which the web W approaches the
~! nip. Here, however, the web W does not go through the nip 134.
The fingers 138 may be supported in other positions depending on
the flow of productO When supported as shown in FIGS . 12 and
~:
: 20 13A, the drum 124 is equipped with annular grooves 124a to
. accommodate the fin~ers 138.
The fingers 138 extend to make contact with the product,
i.e., incipient log, when it reaches the initial holding diameter
o~ about 0.25 inches (6 mm) and stays in contact with the product
?~' 25 until it ~uilds to a diameter where the rider drum 125 can be
moved into the FIG. 13A position (from the FIG. 12 position) at
- 21 -
~,
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. ~pproximately 1.5-2.0 inf~-hes diameter of the incipient log. So,
- the fingers 138 urge the incipient log IL (see FIG. 13A) toward
the nip 134 long enough to bring the rider drum 125 into position
against the incipient log IL'.
As mentioned, in this embodiment, the roll being wound
; remains on the entering upstream side of the nip. The leading- edge E of the cut product simply goes through the nip 141
~ (between the finished product L of FIG. 12 and the drum 121) and
,.
f toward the nip 134 of the upper and lower drums 121, 124 where it
O starts to wind on itself.
,"1;
3 The fingers 138 are each equipped with a friction
surface 156 which has an angular extent as illustrated at 157 for
, ~;,;f
contacting the incipient log IL. The friction surfaces of the
f fingers 38, 138 can be developed by a metallic or plastic
~;~ 15 material since very little coefficient of friction is required
with stationary fingers (high friction material like that used on
the winding drum could be too aggressive and could tear at the
rotating incipient log).
Reference is now made to FIG. 13B where the increase in
the contact angle is illustrated. As pointed out previously, the
~ contact angle is defined by a pair of lines such as at 158 and
`~ 159 which extend from the center of the nip 134 and are tangent
to the incipient log IL' at the points of tangency 150 and 151.
3 The contact angle is seen to be much smaller when the incipient
log IL is closer to the nip 134 as indicated by lines 152 and
, 153.
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~ Again, it will be appreciated that the product or
~ incipient log always remains upstream of the nip in this
; embodiment. Thus, the speed profile is, in effect, somewhat a
mirror image of that shown in 8A at 40 for the embodiment of
FIGS. 1-11. In other words, the speed profile for the embodiment
of FIGS. 12 and 13A as seen in FIG. 12A has first an increasing
speed characteristic at 144 and then at 145 starts to decrease
along the portion 143 of the curve 140.
~¦ Similar to the depiction in FIG. 8A, the speed profile
~ 10 of FIG. 12A may be modified for taper winding under the influence
;~ of the controller 36. For example, where the drum 124 is rotated
faster, the roll product becomes looser at the beginning of the
cycle. This stems from the fact that, with the greater speed
difference between the drums 121 and 124, the incipient log moves
farther away from the point where the two drums are closest and
thus winds more loosely. And to get a prescribed diameter of
logs, the wind must be tighter toward the end of the cycle. So,
in a curve above 140 in FIG. 12, the converse of the situation of
FIG. 8A occurs -- because the drums are farther away from a speed
match.
Both here and with the rider drum 25 of the preceding
embodiment, there may be a speed profile variation -- of speed
variations above and below the profile employed to substantially
eliminate slippage. Again, the character and location of the
profile is determined by the geometry of the system and the
character of the web heing wound. However, in general, the
- 23 -
Z129585
-farther away the variant curve is from a speed match -- with the
web, for example -- the greater the speed differential, and the
: looser the wind.
, FIG. 14
Other than the reverse fold described above, the leading
;/, edge of the web material can pass through the nip of the two
,.....
~ drums 221, 224, if a small bubble is introduced in the web ahead
of the vacuum port (see FIG. 14). As the bubble B enters the nip
.
.~ 234 of the upper and lower drums 221, 224, the bubble will fold
over and initiate the rolling start of wind -- pulling the end
tail back through the nip into the wind as illustrated in FIGS.
:5 14A-D
,,:
The bubble B may be advantageously introduced through
selective application of vacuum through supplemental ports 249.
~ 15 ThiS iS controlled by the controller 36 and may take the form of
.~5 Model PIC 900 available from Giddings & Lewis located in Fond du
:Z Lac, Wisconsin.
~, SUMM~RY
.~
The invention consists of apparatus for the convolute
. 20 winding of a web log and includes a frame 20. Two basic
embodiments are present, differentiated by the addition of 100 in
: the embodiment of FIGS. 12 and 13 over the same numerals without
. the lOO which have been applied to the embodiment of FIGS. 1-11.
The frame rotatably supports a first winding drum 21,
121. This first winding drum is equipped with slot means as at
~j 32, 132. Provided alongside of the first winding drum 21 is a
. ,:, '
` - 24 -
,.,
.' "
:,~
: :
,,
2129585
`-nife drum 22. The knife drum 22 and first winding drum 21
provide means for advancing a web W for travel with the first
winding drum 21, 121. The frame also rotatably supports a second
winding drum 24, 124 which is mounted in th~ frame 20 adjacent
J 5 the first winding drum 21, 121 and located a spaced distance from
the first winding drum to form a nip 34, 134. Still further, the
frame provides pivotal support for a rider drum 25, 125 and which
forms with the first and second winding drums a three drum
cradle.
Means in the form of a vacuum port 33 or pins and the
like are operably associated with the first winding drum 21, 121
for immobilizing a free portion of the web against the surface of
¦ the first winding drum. The immobilizing means 33, 133 is
located a spaced distance from the slot means 32, 132 rearward in
the direction of rotation of the first winding drum to cause a
severed web to fold rearwardly as at RF -- see FIG. 4. Further,
the nip 34, 134 between the first and second winding drums is
less than twice the web thickness. This may be even less in t he
case of the second embodiment.
In the embodiment of FIGS. 1-11 the nip has an upstre~m
side and a downstream side with the upstream side being the sLde
on which the web approaches the nip, and the rider drum 25 is on
the downstream side of the nip.
Further, in the first embodiment, the apparatus inc l~des
control means 36 for selectively moving the second winding ~r~
2~ toward and away from the first winding drum 21 to vary the
- 25 -
'
;
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2iz~ss
spacing therebetween for passage through the nip 34 of a
partially wound log -- as well as importing a speed profile
thereto. Additionally, the first embodiment has finger means 38
for urging an incipient log IL toward the nip 34. The frame lo
is equipped with means for pivotally mounting the finger means as
at 35a. The pivotal mounting means at 35a is operative to
maintain the finger means close to the second winding drum 24 and
thereby prevent the incipient log IL from being pinched between
the finger means 38 and the second winding drum 24. Still
further in summarizing the embodiment of FIGS. 1-11, the first
and second winding drums are equipped with frictional surfaces as
designated at 24a in FIG. 2.
The second embodiment of FIGS. 12 and 13 has the rider
drum on the upstream side of the nip 134. Again, the embodiment
has finger means 138 for urging an incipient log IL toward the
nip 134. Again, the first and second winding drums are equipped
with frictional surfaces.
In both embodiments, the speed profile of the second
' winding drum can be varied as a function of the increasing
i 20 diameter of the web roll on log being wound. In the first
embodiment the speed profile is a reduced speed of the lower
9 drum. In the second embodiment, the product remains on the
incipient or upstream side of the nip and the lower drum speed
profile is in~reased -- see FIG. 12A.
In FIG. 8A relating to the first embodiment, the speed
of the second winding drum 24 is relatively slow in comparison
.~ "`~ "
~ - 26 -
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2~l2958s
~with the constant speed 41 of the first winding drum 21. This
lower drum speed 40 decreases fairly rapidly over the initial
part of the wind as at 44 so as to propel the now partially wound
roll through the space 34' between the first and second winding
drums 21, 24. Thereafter, the speed of the second winding drum
follows a path designated 43 which approaches but does not
precisely equal the surface speed of the first winding drum and
which increases as a function of the increasing diameter of the
partially wound roll or log. Then, at the beginning of the cycle
;~ 10 or close thereto, the speed of the second winding drum (the lower
j drum shown herein) starts at close to match speed with that of
the upper drum 21 but then drops as rapidly as possible as at 44
so as to be ready to start winding of the incipient log which is
now downstream of the nip 34'.
. .15 The inventive method includes the provision of apparatus
. components as listed above and thereafter adjusting the nip
between the winding drums to be less than twice the web thickness
so as to wind the rearwardly folded severed web RF into an
incipient log.
While in the foregoing specification a detailed
description of the invention has been set down for the purpose of
illustration, many variations in the details hereingiven may be
made by those ~killed in the art without departing from the
spirit and scope of the invention.
. 25
. - 27
' .~
