U.S. patent application number 11/253228 was filed with the patent office on 2007-04-19 for center rewinder with two turrets and a bedroll with two transfer positions for transferring a web to each of the turrets.
Invention is credited to Thomas J. Daul, David A. Kacynski.
Application Number | 20070084958 11/253228 |
Document ID | / |
Family ID | 37947267 |
Filed Date | 2007-04-19 |
United States Patent
Application |
20070084958 |
Kind Code |
A1 |
Daul; Thomas J. ; et
al. |
April 19, 2007 |
Center rewinder with two turrets and a bedroll with two transfer
positions for transferring a web to each of the turrets
Abstract
A rewinder includes a bedroll and first and second turrets. Each
turret includes a plurality of rotatable mandrels. The bedroll
includes a web-transferring mechanism for transferring a web on the
bedroll to a mandrel at first and second rotational positions of
the bedroll. The first turret is rotatable to successively move
each of its mandrels to a first web-transferring position adjacent
the first rotational position of the bedroll. The second turret is
rotatable to successively move each of its mandrels to a second
web-transferring position adjacent the second rotational position
of the bedroll. After a web is transferred to a mandrel, the
mandrel rotates to wind the web into a log. As the web is being
wound on a mandrel of one of the turrets, a completed log on the
other turret is removed.
Inventors: |
Daul; Thomas J.; (Oneida,
WI) ; Kacynski; David A.; (Green Bay, WI) |
Correspondence
Address: |
John W. Chestnut;Greer, Burns & Crain, Ltd.
300 South Wacker Drive
Chicago
IL
60606
US
|
Family ID: |
37947267 |
Appl. No.: |
11/253228 |
Filed: |
October 18, 2005 |
Current U.S.
Class: |
242/531 ;
242/532.4 |
Current CPC
Class: |
B65H 2408/2312 20130101;
B65H 2408/23157 20130101; B65H 2301/414222 20130101; B65H 19/283
20130101; B65H 2513/104 20130101; B65H 19/26 20130101; B65H 19/2223
20130101 |
Class at
Publication: |
242/531 ;
242/532.4 |
International
Class: |
B65H 19/28 20060101
B65H019/28 |
Claims
1. An apparatus for transferring a web at two different transfer
positions comprising: a frame, a roll rotatably mounted on the
frame for rotation about a longitudinal axis, the roll having an
outer surface for contacting a web, first and second web-winding
members rotatably mounted on the frame for winding a web, a
web-transferring member movably mounted on the roll and being
movable between a first position and a second position in which the
web-transferring member transfers a web to one of the web-winding
members, and means for moving the web-transferring member to said
second position at a first rotational position of the roll for
transferring a web to the first web-winding member and for moving
the web-transferring member to said second position at a second
rotational position of the roll for transferring a web to the
second web-winding member.
2. The apparatus of claim 1 in which said web-transferring member
includes pins for piercing a web.
3. The apparatus of claim 1 in which the web-transferring member
includes pads for pushing a web away from the outer surface of the
roll.
4. The apparatus of claim 1 in which the roll includes a journal
rotatably mounted on the frame, said means for moving the
web-transferring member including a hub rotatably mounted on the
journal and drive means connecting said hub to said
web-transferring member for moving the web-transferring member
between the first and second positions, and means for varying the
rotational speed of the hub with respect to the rotational speed of
the roll.
5. The apparatus of claim 1 in which the web-transferring member
includes pins movable between a first position in which the pins do
not engage a web on the outer surface of the roll and a second
position in which the pins pierce a web on the outer surface of the
roll and pads movable between a first position in which the pads do
not engage a web on the outer surface of the roll and a second
position in which the pads engage a web on the outer surface of the
roll, the roll including a journal rotatably mounted on the frame,
first and second hubs rotatably mounted on the journal, first drive
means connecting the first hub to said pins for moving the pins
between the first and second positions, second drive means
connecting the second hub to said pads for moving the pads between
the first and second positions, means for varying the rotational
speed of the first hub with respect to the rotational speed of the
roll, and means for varying the rotational speed of the second hub
with respect to the rotational speed of the roll.
6. The apparatus of claim 1 including first and second turrets
rotatably mounted on the frame for rotation about a longitudinal
axis, said first web-winding member being rotatably mounted on the
first turret and said second web-winding member being rotatably
mounted on the second turret, said first turret being rotatable to
move said first web-winding member to a first web-transferring
position adjacent said first rotational position of said roll
whereby a web may be transferred from the roll to the first
web-winding member, said second turret being rotatable to move said
second web-winding member to a second web-transferring position
adjacent said second rotational position of said roll whereby a web
maybe transferred from the roll to the second web-winding
member.
7. An apparatus for transferring a web at two different transfer
positions comprising: a frame, a roll rotatably mounted on the
frame for rotation about a longitudinal axis, the roll having an
outer surface for contacting the web, a first turret rotatably
mounted on the frame for rotation about a longitudinal axis, a
plurality of web-winding members rotatably mounted on the first
turret, rotation of the first turret bringing each of the
web-winding members of the first turret into a first transfer
position which is adjacent the roll at a first rotational position
of the roll, a second turret rotatably mounted on the frame for
rotation about a longitudinal axis, a plurality of web-winding
members rotatably mounted on the second turret, rotation of the
second turret bringing each of the web-winding members of the
second turret into a second transfer position which is adjacent the
roll at a second rotational position of the roll, whereby a web on
the roll can be transferred to a web-winding member on the first
turret at the first rotational position of the roll and can be
transferred to a web-winding member on the second turret at the
second rotational position of the roll.
8. The apparatus of claim 7 including means for transferring a web
to a web-winding member on the first turret at the first rotational
position of the roll and for transferring a web to a web-winding
member on the second turret at the second rotational position of
the roll.
9. The apparatus of claim 8 in which said transfer means includes a
pusher movably mounted on the roll.
10. The apparatus of claim 9 in which said transfer means includes
means on a web-winding member on the first turret for holding a web
and means on a web-winding member on the second turret for holding
a web.
11. The apparatus of claim 10 in which each of said means for
holding a web includes adhesive on the web-winding member.
12. The apparatus of claim 8 in which said transferring means
includes adhesive on a web-winding member on the first turret and
adhesive on a web-winding member on the second turret.
13. The apparatus of claim 7 including a blade mounted on the frame
adjacent said roll for severing a web on the roll, pins movably
mounted on the roll for movement between a retracted position below
the surface of the roll and an extended position above the surface
of the roll for retaining a web on the roll, and means for moving
the pins from the extended position to the retracted position as
the roll moves toward the first rotational position and for moving
the pins from the extended position to the retracted position as
the roll moves toward the second rotational position.
Description
BACKGROUND
[0001] This invention relates to a center rewinder having two or
more turrets and a bedroll with two or more transfer positions for
transferring a web to a web-winding member such as a mandrel at
each of the transfer positions.
[0002] Rewinders are used to convert large parent rolls of paper
into retail sized rolls of bathroom tissue and paper towels. Two
types of rewinders are commonly used--center rewinders and surface
rewinders. Center rewinders are described, for example, in U.S.
Reissue Pat. No. 28,353 and wind the web on a core which is rotated
by a mandrel. Surface rewinders are described, for example, in U.S.
Pat. Nos. 4,723,724 and 5,104,055 and wind the web on a core which
is rotated by a three roll cradle. The terms "rewinders" and
"winders" are sometimes used interchangeably.
[0003] The critical operation in both center rewinders and surface
rewinders is the sequence of steps referred to as cutoff and
transfer. The web must be severed to end the winding of one roll,
the leading edge of the severed web must be transferred to a new
core, and the new core must be rotated to begin winding a new roll.
These steps must be accomplished repeatedly and reliably while the
web is moving at high speed. It is also desirable that each roll
have exact sheet count and that the web is wound uniformly and
substantially without wrinkles.
[0004] The term "bedroll" refers to the main winding roll of a
rewinder, either a center rewinder or a surface rewinder.
[0005] As described in U.S. Reissue Pat. No. 28,353, a bedroll is
commonly used in conjunction with a chopper roll to sever the web
after a predetermined length has been wound into a log and to
transfer the leading edge of the severed web to a new core in a
continuous winding process. In center rewinders a latch mechanism
is commonly used to retain the severing and transferring mechanism
in an inoperative position until the proper length of web has been
wound onto the log. A cam follower is controlled by an electric
solenoid or pneumatic cylinder to unlatch the latch mechanism to
release the severing and transferring mechanism. The severing and
transferring mechanism is then controlled by one or more cams to
perform the cutoff and transfer operations on the web. The latch is
thereafter reset by the cam to retain the severing and transferring
mechanism in the inoperative position.
[0006] A conventional latch mechanism and a severing and
transferring mechanism for center rewinders is described in detail
in U.S. Reissue Pat. No. 28,353. The severing and transfer
mechanism includes transfer pins 56, cutoff blades 58 and 59, and
transfer pads 55, all of which are movably mounted in the bedroll.
When the severing and transfer mechanism is unlatched, the pins 56
hold the web against the rotating bedroll while the web is severed
by a chopper roll 49 and the blades 58 and 59 (see FIGS. 20 and
21). The transfer pads thereafter urge the leading end of the
severed web against a new core 53 (FIGS. 22 and 23). A solenoid is
actuated to unlatch the latch mechanism.
[0007] Surface rewinders sold by Paper Converting Machine Company
of Green Bay, Wisconsin under the name "Magnum" include similar
movable pins in a bedroll for holding the severed web against the
bedroll and a similar latch mechanism for retaining the pins in an
inoperative position until the web is to be severed. A cutoff knife
is movably mounted in a chopper roll and is retained in an
inoperative position by a latch mechanism which is similar to the
latch mechanism which is used on the bedroll of a center
rewinder.
[0008] U.S. Pat. No. 6,179,241 describes a latch mechanism which is
controlled by a camshaft which is mounted axially in the bedroll
and by a servo motor which rotates the camshaft. The servo motor
normally rotates the camshaft in the same direction and at the same
speed as the bedroll. When the web is to be severed, the speed of
the servo motor is either increased or decreased to rotate the
camshaft relative to the bedroll. The rotation of the camshaft
allows push rods in the bedroll to move radially inwardly to
release the severing and transferring mechanism. Cam followers for
the severing and transferring mechanism engage a stationary cam and
control the movement of the mechanism. After the web is severed and
transferred, the camshaft is rotated to force the push rods
radially outwardly to relatch the severing and transferring
mechanism.
[0009] U.S. Pat. No. 6,513,750 describes a bedroll which includes a
lockout cam, a pin cam, and a pad cam for operating the pins and
pads instead of the cams, latch mechanism, and solenoid of U.S.
Reissue Pat. No. 28, 353. FIGS. 26 and 27 of the '750 patent
illustrate a rewinder which omits the lockout cam, pin cam, and pad
cam and uses rotatable hubs to rotate the pin shaft and pad shaft.
FIGS. 28 and 29 of the '750 patent illustrate another rewinder in
which the lockout is omitted but which includes a pin cam and a pad
cam.
[0010] In all of the foregoing patents which describe a center
rewinder, the rewinder includes a single rotatable turret. A
plurality of mandrels are rotatably mounted on the turret, and the
turret indexes to move the mandrels successively to a
web-transferring position adjacent the bedroll. The bedroll has a
single transfer position at a particular rotational position of the
bedroll at which the web is transferred to a mandrel or to a core
which is mounted on the mandrel. The operating mechanism for the
pins and the pads is designed to move the pins and pads so that
transfer occurs at that single transfer position.
[0011] U.S. Pat. No. 5,497,959 describes a coreless winder with two
transfer positions. The bedroll uses vacuum and air pressure for
maintaining control over the web during cutoff and transfer.
[0012] U.S. Pat. No. 5,226,611 describes a surface winder with two
transfer positions. The rewinder includes a vacuum transfer roll 28
and two additional vacuum rolls 40 and 42 to advance the web to two
surface winding stations.
[0013] U.S. Pat. No. 3,157,371 describes a winder with two turrets.
This type of winder is typically used to wind a slit web. Part of
the web is wound on one turret while the other part of the web is
wound on the other turret. This patent does not describe using two
turrets and two separate transfer positions for transferring a web
from a bedroll to the turrets.
SUMMARY OF THE INVENTION
[0014] One embodiment of the invention provides a bedroll with two
or more transfer positions for transferring a web to mandrels or
cores. The mandrels or cores may or may not be mounted on turrets.
Another embodiment of the invention uses the bedroll with two or
more turrets for transferring and winding a web on multiple
turrets. A rewinder with multiple turrets and multiple transfer
positions is capable of operating at a substantially increased
cycle rate. For example, a center rewinder having a single turret
and a single transfer position is generally limited to producing
about 35 logs per minute. However, a rewinder in accordance with
the invention having two turrets and two transfer positions can
produce about 70 logs per minute.
DESCRIPTION OF THE DRAWING
[0015] The invention will be explained in conjunction with
illustrative embodiments shown in the accompanying drawing, in
which
[0016] FIG. 1 illustrates a prior art center rewinder which
includes a single turret and a bedroll having a single transfer
position;
[0017] FIG. 2 illustrates a rewinder in accordance with the
invention which includes two turrets and a bedroll with two
transfer positions, the web being wound on the right turret;
[0018] FIG. 3 is a view similar to FIG. 2 showing the bedroll in
the cutoff position and a log on the right turret completing its
wind;
[0019] FIG. 4 illustrates continued rotation of the bedroll and
indexing of the left turret to move a mandrel to the transfer
position and to move a completed log toward a tailseal
apparatus;
[0020] FIG. 5 illustrates the bedroll at one of its transfer
positions and the log on the left turret indexed to a glue
applicator for applying tailseal adhesive to the log;
[0021] FIG. 6 illustrates the rewinder after transfer to a mandrel
on the left turret;
[0022] FIG. 7 illustrates the left turret in a winding position in
which the web is being wound on a mandrel on the left turret;
[0023] FIG. 8 illustrates a chopper roll and a bedroll which is
equipped with pins for retaining a web on the bedroll and pads for
transferring the web to a core;
[0024] FIG. 9 is a view similar to FIG. 8 showing the chopper roll
and bedroll in the web cutoff position;
[0025] FIG. 10 is a view similar to FIG. 8 showing the bedroll in
one of its transfer positions;
[0026] FIG. 11 is a view similar to FIG. 10 showing the bedroll in
a second transfer position;
[0027] FIG. 12 illustrates a mechanism for operating the pins and
pads of the bedroll of FIG. 8; and
[0028] FIG. 13 is an enlarged fragmentary view of the mechanism of
FIG. 12;
[0029] FIG. 14 is a timing chart for one of the turrets;
[0030] FIG. 15 is a timing chart for the other turret;
[0031] FIG. 16 is a timing chart which combines the timing charts
for the two turrets;
[0032] FIG. 17 is a timing chart for the roll stripper conveyor for
one of the turrets;
[0033] FIG. 18 is a timing chart for the roll stripper conveyor for
the other turret; and
[0034] FIG. 19 is a timing chart which combines the timing charts
for the two roll strippers.
DESCRIPTION OF SPECIFIC EMBODIMENTS
[0035] FIG. 1 illustrates a prior art center rewinder 20 of the
type which is described in U.S. Pat. No. 6,513,750. The rewinder 20
includes a frame 21 and a bedroll 22 which is rotatably mounted on
the frame. A turret assembly 23 is rotatably mounted on the frame
adjacent the bedroll. As is well known in the art, the turret
assembly includes a plurality of rotating mandrels 24 on which
paperboard cores are mounted. An adhesive-applying apparatus 25
applies transfer adhesive to a new core before each winding
cycle.
[0036] A web W is advanced by draw rolls 26 through a perforator 27
to the bedroll 22. The perforator forms longitudinally spaced
transverse lines of perforation in the web.
[0037] The surface speed of the bedroll matches the speed of the
web, and the bedroll delivers the web to a log L which is wound on
the mandrel at about the 1:00 o'clock position of the turret. When
the proper length of web has been wound on the log, the web will be
severed by a chopper roll 28 and a new winding cycle will
begin.
[0038] The bedroll 22 is equipped with a pin and pad assembly 30
which is described in detail in U.S. Pat. No. 6,513,750. A similar
pin and pad assembly is described in U.S. Reissue Pat. No.
28,353.
[0039] As is well known in the art, such a pin and pad assembly
includes a plurality of transfer pins for holding the web against
the rotating bedroll while the web is severed by the chopper roll.
The transfer pads thereafter strip the web from the pins and urge
the leading end of the severed web against a new core to begin a
new winding cycle. The pins and pads are mounted on a pin shaft and
a pad shaft, respectively, which are independently rotatable by the
operating mechanism of the pin and pad assembly as described in
U.S. Pat. No. 6,513,750 and U.S. Reissue Pat. No. 28,353.
[0040] Referring now to FIGS. 2-7, the inventive rewinder 30
includes a frame 31, a bedroll 32 which is rotatably mounted on the
frame, and a pair of turrets 33 and 34 which are rotatably mounted
on the frame. The turrets may be conventional and each turret
includes a plurality of mandrels 35. FIG. 2 illustrates three
mandrels on each turret, but more or less may be used. Each mandrel
is direct coupled to a conventional drive motor. A paperboard core
may be mounted on each mandrel before the web is wound on the
mandrel, or the web can be wound directly on a coreless mandrel. If
the web is wound on cores, a line of transfer adhesive maybe
applied to each core as the core is loaded onto a mandrel. The
position of the line of adhesive or glue is maintained by a motor
encoder.
[0041] A web W is advanced by conventional infeed draw rolls (not
shown) through a perforator (not shown) and over outfeed draw rolls
37 and the bedroll 32. As will be described hereinafter, the web is
fed from the bedroll alternatively to the right and the left
turrets 33 and 34. In FIG. 2 the web is being wound on a mandrel of
the right turret 33 to form a log L.sub.1. When the proper length
of web has been wound on the log L.sub.1, the web is severed by a
chopper roll 38.
[0042] A previously wound log L.sub.2 is mounted on another mandrel
of the right turret. Previously wound logs L.sub.3 and L.sub.4 are
mounted on mandrels of the left turret 34.
[0043] A rider roll 40 is mounted on a swingable arm 41 and is in
contact with the winding log L.sub.1. The rider roll alternates
between the two turrets, depending on which turret is winding
product. The position of the arm 41 and thus the rider roll 40 is
controlled by a servo motor which is operated by the programmable
logic control (PLC) of the rewinder. The diameter of the wound log
is controlled by the rider roll position and the metered winding
speed of the web, both of which are controlled by the PLC. Control
of product diameter by rider roll position reduces sensitivity to
the tensile strength of the perforations and increases product
range and production efficiency.
[0044] At the completion of the wind, both product diameter and
firmness are measured, e.g., by a laser PE and a load cell. This
information is fed back in a closed loop to controls upstream of
the bedroll to optimize runability.
[0045] The bedroll 32 includes pins 44 and pads 45 of the type
which are described in U.S. Pat. No. 6,513,750. Just before the web
is severed by the chopper roll 38, the pins 44 are moved outwardly
to pierce the web and to hold the web against the surface of the
bedroll after the web is severed. As will be described hereinafter,
the pads 45 are extended to strip the web off of the pins and to
press the leading end of the severed web against a new core to
begin a new winding cycle.
[0046] Exact sheet count in a wound log can be obtained either by
matching the sheet count to the circumference of the bedroll or by
slipping the bedroll relative to the web prior to cutoff and
transfer. Slipping the bedroll relative to the web to adjust sheet
count is well known in the art and is described for example, in
U.S. Pat. No. 4,687,153.
[0047] When the bedroll pins are extended to engage the web, the
speed of the bedroll is matched to web speed and remains matched
until just after transfer to eliminate sensitivity to web tensile
strength and web stretch. Activation of the pins is controlled by a
servo motor, which enables variable pin displacement based on the
position of the winding turret, thereby permitting increased cycle
rates of 60 to 70 logs per minute.
[0048] In FIG. 2 the web is being wound on the right turret 33 to
form log L.sub.1, and the rider roll 40 is in contact with the
winding product. Both the right and left turrets are stationary.
The pins 44 and pads 45 are retracted inside of the outer surface
of the bedroll 32.
[0049] FIG. 3 illustrates the web being severed by the chopper roll
38. The pins 44 are extended out of the bedroll beyond the outer
surface of the bedroll to engage the web. A blade 48 (FIG. 4) on
the chopper roll 38 extends through the web and engages with blades
on the pins to cut the web on one of the perforation lines of the
web. The right turret 33 remains stationary, but the left turret 34
is in the process of indexing clockwise. The log L.sub.3 (FIG. 2)
has been stripped from its mandrel on the left turret by a
conventional log-stripping device.
[0050] FIG. 4 illustrates the bedroll and left turret just before
transfer. The pins 44 are in the process of being retracted into
the bedroll 32, but the pins still engage the web and carry the web
for transfer to the core on mandrel 35a of the left turret 34. The
left turret is indexing clockwise to rotate the mandrel 35a to the
transfer position illustrated by the radial line T. The trailing
end of the severed web continues to be wound on the log
L.sub.1.
[0051] The completed log L.sub.4 on the left turret 34 is being
indexed to a tailseal apparatus 50. The tailseal apparatus includes
an air nozzle 51 which provides an air blast to blow the tail 52 of
the log L.sub.4 past the tailseal apparatus.
[0052] FIG. 5 illustrates one of the transfer positions of the
bedroll 32. The left turret 34 has indexed the mandrel 35a to the
transfer position of the left turret indicated by the radial line
T. The pins 44 are retracted into the bedroll 32, and the pads 45
strip the web from the pins and press the web onto the glued core
carried by the mandrel 35a, thereby transferring the web to the
glued core. The transfer glue on the core adhesively transfers the
web to the core. The trailing end of the severed web continues to
be wound on the log L.sub.1 on the right turret.
[0053] The left turret is indexing clockwise at peak velocity. A
glue applicator roll 53 of the tailseal apparatus 50 rotates with a
speed which is matched to the indexing speed of the left turret and
prints a line of adhesive on the wound log L.sub.4.
[0054] In FIG. 6 the leading end of the severed web has been
transferred to the core on the mandrel 35a, and a new log L.sub.5
begins to wind. The pins 44 and pads 45 are retracted into the
bedroll 32. The left turret 34 continues to index clockwise, and
the rider roll 40 begins to move from the right turret to the left
turret. The glue applicator 53 in the tailseal apparatus returns to
a dwell position. The clockwise indexing of the left turret moves
the log LA and its tail 52 toward a presser roll 56.
[0055] In FIGS. 7 both the left and right turrets are stationary.
The web W is being wound on the log L.sub.5 on the left turret. The
log L.sub.4 has been moved past the presser roll 56 so that its
tail 52 is secured by the line of tailseal glue which was applied
by the tailseal apparatus 50. The rider roll 40 engages the winding
log L.sub.5 on the left turret.
[0056] The portion of the winding cycle which is illustrated in
FIG. 7 corresponds generally to the portion of the winding cycle
which is illustrated in FIG. 2, except that the winding log L.sub.5
in FIG. 7 is on the left turret rather than on the right turret. It
will be understood by those skilled in the art that the right
turret will be indexed counterclockwise from its FIG. 7 position to
move the wound log L.sub.1 past a tailseal apparatus 58 for the
right turret which will apply a line of tailseal glue to the log
L.sub.1 in the manner previously described with respect to the
tailseal apparatus 50. As the right turret continues to index
counterclockwise, the tail of the wound log L.sub.1 will be pressed
against the log by a presser roll 59.
[0057] When the log L.sub.5 approaches the end of its winding
cycle, the right turret 33 will be indexed counterclockwise to move
the mandrel 35b thereof into the transfer position of the right
turret which is indicated by the radial line T in FIG. 7. The pins
44 will be extended to hold the web while the web is severed by the
chopper roll 38, and the pins 44 will carry the web to the second
transfer position of the bedroll, which is aligned with the radial
line T of the right turret in FIG. 7. The pins will be retracted,
and the pads 45 will be extended to strip the web from the pins and
to transfer the web to the glued core on the mandrel 35b. The new
log will then be wound on the right turret, and the winding cycle
will be repeated.
[0058] Referring to FIG. 8, the transfer pins 44 are mounted on a
pin shaft 65, and the transfer pads 45 are mounted on a pad shaft
66. The transfer pins 44 are clamped to the pin shaft 65 by clamps
67. The pads 45 are clamped to the pad shaft 66 by clamps 68. A
pair of spaced-apart cutoff blades 69 is mounted on each of the
transfer pins 44.
[0059] FIG. 9 illustrates the bedroll 32 in the cutoff position.
The pin shaft 65 has been rotated counter clockwise so that the
pins 44 extend beyond the outer surface of the bedroll 32 and
impale the web (not shown in FIG. 9 for clarity of illustration)
which wraps a portion of the outer surface of the bedroll. One of
the blades 48 on the chopper roll 38 enters the space between the
cutoff blades 69 on the pins 44 to sever the web. After the web is
severed, the leading end portion of the severed web is held on the
rotating bedroll by the pins 44. The transfer pads 45 remain
retracted in the bedroll 32.
[0060] FIG. 10 illustrates the bedroll 32 in its transfer position
for the left turret 34. The pin shaft 65 has been rotated clockwise
to retract the pins 44, and the pad shaft 66 has been rotated
clockwise to move the pads 45 beyond the outer surface of the
bedroll so that the pads strip the web (not shown in FIG. 10 for
clarity of illustration) from the pins 44 and presses the web
against the core on the mandrel 35a of the left turret 34. The web
is retained on the core by the transfer glue which was previously
applied to the core.
[0061] FIG. 11 illustrates the bedroll 32 in its transfer position
for the right turret 33. Again, the pin shaft 65 and pad shaft 66
are rotated to retract the pins 44 and extend the pads 45 to strip
the web (not shown) from the pins and to press the web against the
core on the mandrel 35b of the right turret.
[0062] FIGS. 12 and 13 illustrate one specific embodiment of a
mechanism for operating the pins 44 and pads 45 of the bedroll in
more than one transfer position. The structure of FIGS. 12 and 13
is also illustrated and described in U.S. Pat. No. 6,513,750, to
which reference can be had for a detailed description. However, the
bedroll of the '750 patent has only one transfer position.
[0063] The pin shaft 65 and pad shaft 66 are rotatably mounted in
the bedroll 32, and are driven by timing belts 72 and 73. The
timing belt 73 is driven by hub 74 which is rotatably mounted on
the journal 75 of the bedroll. The timing belt 72 is driven by a
hub 76 which is rotatably mounted on the hub 74. The hubs 74 and 76
are driven through timing belts 77 and 78 by differentials 79 and
80 and electric servo motors 81 and 82. The servos 81 and 82 are
controlled by the PLC of the rewinder.
[0064] A pulley 83 on the bedroll journal 75 is connected to
pulleys on the differentials 79 and 80 by belt 84. The bedroll is
driven by a servo motor which is controlled by the PLC of the
rewinder.
[0065] The hubs 74 and 76 are rotated at bedroll speed during most
of the winding cycle by the differentials 79 and 80. When rotation
of the pin shaft 65 or pad shaft 66 is required, the appropriate
servo 81 or 82 provides additional rotational speed to rotate the
pin shaft or pad shaft relative to the bedroll. As described in
U.S. Pat. No. 6,513,750, the differentials are mechanical motion
"combiners", and the output from each differential is the sum of a
constant rpm input from the bedroll journal plus the trim rpm input
from the servo 81 or 82.
[0066] The pin and pad shafts need to rotate relative to the
bedroll in order to execute cutoff and transfer and also need to
rotate relative to each other. The extension of the pins varies
depending upon the position of the mandrel relative to the bedroll.
The extension of the pads is constant when the pads are
extended.
[0067] With the rewinder illustrated in the drawings, which
includes two turrets, cutoff and transfer requires between one and
two bedroll revolutions. The perforator roll is the master axis,
with the distance between perforation and cutoff remaining
constant. The movement of either the right or left turret, along
with the movement of the pin and pad shafts, is referenced off of
the master.
[0068] The following timing chart reflects the bedroll positions
for two turrets. It will be apparent to those skilled in the art
that the timing chart could be expanded to provide additional
transfer positions if more than two turrets are used and could also
be modified if means other than turrets are used to move the
mandrels into the transfer positions. TABLE-US-00001 Timing Chart
Turret: Bedroll Position Ref.: Notes: Right Turret 0 deg (0 rev)
Bedroll phasing hub & bedroll at matched speed. Pin timing hub
is at start of move. Web winding on right turret. 180 deg (1/2 rev)
Pin timing drive is phased to fully extend pins. Cutoff has
occurred. Pad timing hub is phasing with pads moving outward. 270
deg (3/4 rev) Pads are retracting into bedroll. Transfer has
occurred. Pins are fully retracted into bedroll. 360 deg (1 rev)
Pads are fully retracted into bedroll. (reset for next cutoff &
transfer) Left Turret 0 deg (0 rev) Bedroll phasing hub &
bedroll at matched speed. Pin timing hub is at start of move. Web
winding on left turret. 180 deg (1/2 rev) Pin timing drive is
phased to fully extend pins. Cutoff has occurred. 270 deg (3/4 rev)
Pads are extending out from the bedroll. Pins are fully extended
from the bedroll. 360 deg (1 rev) Pads are retracting into bedroll.
Transfer has occurred. Pins are fully retracted into bedroll. 450
deg (11/4 rev) Pads are fully retracted into bedroll. (reset for
next cutoff & transfer)
[0069] Each turret indexes or rotates during about 25% of the
winding cycle and dwells or is stationary for about 75% of the
winding cycle.
[0070] A rewinder using more than one turret for transfer and
winding makes possible cycle rates of up to 70 logs per minute or
more. That is double the cycle rate of current rewinders using a
single turret.
[0071] Other mechanisms for actuating the pins and pads could also
be used. For example, the pin shaft and pad shaft could be operated
by cams or separate timing belt drives.
[0072] FIG. 14 is a timing chart for one of the turrets 33 or 34,
for example, the right turret 33. The chart shows the position,
velocity, and acceleration of the turret. The x axis is machine
degrees and represents two winding cycles of the rewinder or
720.degree.. The y axis is turret index position in degrees.
[0073] The right turret dwells during the first 300.degree. of the
machine cycle and then moves 120.degree. during the next
120.degree. of the machine cycle. The right turret then dwells for
the remaining 300.degree. of two winding cycles.
[0074] The vertical line just prior to movement of the turret at
300.degree. represents the return to start since the chart shows
the turret rotating only 120.degree. rather than showing three
separate turret moves of 120.degree. for a total movement of
360.degree..
[0075] FIG. 15 is a similar timing chart for the left turret 34.
Again, the turret moves 120.degree. during two winding cycles of
the machine.
[0076] FIG. 16 is a timing chart for both of the turrets.
[0077] FIG. 17 is a timing chart for a conventional roll stripper
conveyor which strips the wound log from one of the mandrels of the
right turret when the turret is stationary.
[0078] FIG. 18 is a similar timing chart for the roll stripper
conveyor for the left turret.
[0079] FIG. 19 is a timing chart for both of the roll stripper
conveyors.
[0080] The timing charts for the core loading axis for each turret
would be similar. Two conventional core loaders are driven
synchronously with the roll strip conveyors. Core loading onto an
empty mandrel of a turret takes place at the same time as roll
stripping on that turret and while the turret dwells.
[0081] As used herein, the term "web-winding member" can refer to a
mandrel, a core, or an equivalent device which rotates to wind the
web. The term "web-transferring member" can refer to either or both
of the transfer pins and transfer pads or equivalent devices for
transferring the web from the bedroll to the rotating core or
mandrel
[0082] While in the foregoing specification a detailed description
of specific embodiments was set forth for the purpose of
illustration, it will be understood that many of the details herein
given may be varied considerably by those skilled in the art
without departing from the spirit and scope of the invention.
* * * * *