U.S. patent application number 15/500316 was filed with the patent office on 2017-07-27 for rewinding machine and method for producing logs of web material.
This patent application is currently assigned to FABIO PERINI S.P.A.. The applicant listed for this patent is FABIO PERINI S.P.A.. Invention is credited to Romano Maddaleni, Franco Montagnani, Roberto Morelli.
Application Number | 20170210584 15/500316 |
Document ID | / |
Family ID | 51662235 |
Filed Date | 2017-07-27 |
United States Patent
Application |
20170210584 |
Kind Code |
A1 |
Morelli; Roberto ; et
al. |
July 27, 2017 |
REWINDING MACHINE AND METHOD FOR PRODUCING LOGS OF WEB MATERIAL
Abstract
The rewinding machine includes a first winding cradle formed
between a first winding roller, a second winding roller and a third
winding roller. The first winding roller and the second winding
roller define a nip through which there pass the winding cores with
the web material being wound around them. The rewinding machine
also includes a feed path of the winding cores that pass between
the first winding roller and the third winding roller. A second
winding cradle is formed between the first winding roller, the
second winding roller and a fourth winding roller. The rewinding
machine also includes a rolling surface extending around the first
winding roller and defining a feed channel of the winding
cores.
Inventors: |
Morelli; Roberto; (S. Maria
a Colle, IT) ; Montagnani; Franco; (Palaia, IT)
; Maddaleni; Romano; (Bientina, IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FABIO PERINI S.P.A. |
Lucca |
|
IT |
|
|
Assignee: |
FABIO PERINI S.P.A.
Lucca
IT
|
Family ID: |
51662235 |
Appl. No.: |
15/500316 |
Filed: |
July 30, 2015 |
PCT Filed: |
July 30, 2015 |
PCT NO: |
PCT/EP2015/067516 |
371 Date: |
January 30, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65H 2301/4182 20130101;
B65H 19/267 20130101; B65H 2402/31 20130101; B65H 19/26 20130101;
B65H 19/22 20130101; B65H 2301/41376 20130101; B65H 18/20 20130101;
B65H 2301/41358 20130101; B65H 19/2269 20130101; B65H 2408/235
20130101 |
International
Class: |
B65H 19/22 20060101
B65H019/22; B65H 18/20 20060101 B65H018/20 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 31, 2014 |
IT |
FI2014A000181 |
Claims
1-23. (canceled)
24. An automatic continuous peripheral rewinding machine for
producing logs of web material wound around winding cores,
comprising: a first winding cradle formed between a first winding
roller, a second winding roller and a third winding roller; the
first winding roller and the second winding roller defining a nip
through which winding cores with web material being wound there
around pass; a second winding cradle formed between the first
winding roller, the second winding roller and a fourth winding
roller; the third winding roller being placed upstream of the nip
and the fourth winding roller being placed downstream of the nip,
with respect to direction of feed of the winding cores through the
nip; a rolling surface extending around the first winding roller
and defining a winding core feed channel, between the rolling
surface and the first winding roller; the rolling surface being
configured and arranged with respect to the first winding roller
such that the winding cores are fed by rolling in contact with the
rolling surface and with the web material entrained around the
first winding roller.
25. The rewinding machine as claimed in claim 24, further
comprising a severing member of the web material adapted to sever
the web material at end of winding of a log in the second winding
cradle.
26. The rewinding machine as claimed in claim 25, wherein the
severing member is adapted to co-act with the first winding
roller.
27. The rewinding machine as claimed in claim 25, wherein the
severing member is adapted to pinch the web material against the
first winding roller and sever the web material generating in the
web material a tension greater than a breaking point of the web
material.
28. The rewinding machine as claimed in claim 26, wherein the
severing member is adapted to pinch the web material against the
first winding roller and sever the web material generating in the
web material a tension greater than a breaking point of the web
material.
29. The rewinding machine as claimed in claim 27, wherein the
severing member is adapted to sever the web material between a new
core introduced in the winding core feed channel and a log being
formed in the second winding cradle between the severing member and
the log being formed in the second winding cradle.
30. The rewinding machine as claimed in claim 28, wherein the
severing member is adapted to sever the web material between a new
core introduced in the winding core feed channel and a log being
formed in the second winding cradle between the severing member and
the log being formed in the second winding cradle.
31. The rewinding machine as claimed in claim 25, wherein the
severing member is adapted to enter the winding core feed channel
and cooperate with the first winding roller in a point downstream
of a winding core inserted into the winding core feed channel.
32. The rewinding machine as claimed in claim 26, wherein the
severing member is adapted to enter the winding core feed channel
and cooperate with the first winding roller in a point downstream
of a winding core inserted into the winding core feed channel.
33. The rewinding machine as claimed in claim 24, wherein the
rolling surface extends from an inlet of the winding core feed
channel to the third winding roller.
34. The rewinding machine as claimed in claim 25, wherein the
rolling surface extends from an inlet of the winding core feed
channel to the third winding roller.
35. The rewinding machine as claimed in claim 33, wherein a winding
cores feed path extends beyond the winding core feed channel and
between the first winding roller and the third winding roller, to
reach the first winding cradle.
36. The rewinding machine as claimed in claim 34, wherein a winding
cores feed path extends beyond the winding core feed channel and
between the first winding roller and the third winding roller, to
reach the first winding cradle.
37. The rewinding machine as claimed in claim 24, wherein the first
winding roller, the second winding roller, the third winding roller
and the fourth winding roller are arranged to carry out a first
part of winding of a log in the first winding cradle between the
first winding roller, the second winding roller and the third
winding roller and a last part of winding of a log in the second
winding cradle, between the first winding roller, the second
winding roller and the fourth winding roller.
38. The rewinding machine as claimed in claim 37, wherein the third
winding roller and the fourth winding roller each have a movable
axis and are adapted to move orthogonally to the axis following
movement of a log during a step of log diameter increase and of
transfer from the first winding cradle to the second winding
cradle.
39. The rewinding machine as claimed in claim 24, wherein at least
one of said first winding roller and said second winding roller has
a movable axis, to control distance between the first winding
roller and the second winding roller and dimension of the nip
between the first winding roller and the second winding roller.
40. The rewinding machine as claimed in claim 24, wherein the first
winding roller has a fixed axis and the second winding roller has a
movable axis, and wherein the first winding roller has a larger
diameter than the second winding roller.
41. The rewinding machine as claimed in claim 24, wherein the first
winding roller and the second winding roller each have a movable
axis, to move away from and toward each other in a symmetrical
manner.
42. The rewinding machine as claimed in claim 24, wherein movement
of the first winding roller, of the second winding roller, of the
third winding roller and of the fourth winding roller during
winding of a log is provided so that: a first part of winding of
the log takes place with the log in contact with the first winding
roller, the second winding roller and the third winding roller; a
second part of winding of the log takes place with the log in
contact with the first winding roller, the second winding roller,
the third winding roller and the fourth winding roller; a third
part of winding of the log takes place with the log in contact with
the first winding roller, the second winding roller and the fourth
winding roller.
43. The rewinding machine as claimed in claim 24, wherein the
rolling surface comprises a first part stationary with respect to a
supporting structure of the rewinding machine, and a second part
that moves together with an axis of the third winding roller.
44. The rewinding machine as claimed in claim 24, further
comprising a pair of motorized centers, configured and arranged to
engage with a winding core during at least a part of a winding
cycle, the motorized centers following feed movement of the winding
core between winding rollers.
45. The rewinding machine as claimed in claim 24, wherein the first
winding roller, around which the web material is driven, has a
diameter larger than a diameter of the second winding roller.
46. The rewinding machine as claimed in claim 24, wherein the first
winding roller has an axis which is stationary with respect to a
load-bearing structure of the rewinding machine, and the second
winding roller has an axis which is movable with respect to the
load-bearing structure of the machine, to allow or facilitate
passage of a log being formed through the nip defined between the
first winding roller and the second winding roller.
47. A method for winding a web material and sequentially forming
logs of said web material wound around winding cores, comprising
steps of: feeding a web material around a first winding roller of a
first winding cradle formed by the first winding roller, a second
winding roller and a third winding roller, the first winding roller
and the second winding roller defining, with a fourth winding
roller, a second winding cradle; inserting a first winding core
into a feed channel formed between the first winding roller and a
rolling surface extending around the first winding roller, and
feeding the first winding core by rolling in contact with the
rolling surface and with the web material entrained around the
first winding roller and feeding the first winding core along an
insertion path between the first winding roller and the third
winding roller and inserting the first winding core into the first
winding cradle; carrying out a first part of a winding cycle of a
first log around the first winding core in the first winding
cradle, transferring the first log being formed from the first
winding cradle into the second winding cradle through a nip defined
between the first winding roller and the second winding roller;
carrying out a second part of a winding cycle of the first log in
the second winding cradle; at the end of winding of the first log
in the second winding cradle, inserting a second winding core into
the feed channel and along the insertion path between the first
winding roller and the third winding roller and inserting the
second winding core into the first winding cradle.
48. The method as claimed in claim 47, further comprising steps of:
inserting the second winding core against the first winding roller
pinching the web material between the second winding core and the
first winding roller, and severing the web material between the
first log in the second winding cradle and the second winding
core.
49. The method as claimed in claim 47, further comprising a step of
acting with a severing member on the web material to sever the web
material thus generating a trailing edge of the first log and a
leading edge with which to start winding a second log around the
second winding core.
50. The method as claimed in claim 48, further comprising a step of
acting with a severing member on the web material to sever the web
material thus generating a trailing edge of the first log and a
leading edge with which to start winding a second log around the
second winding core.
51. The method as claimed in claim 49, further comprising a step of
pinching the web material between the severing member and the first
winding roller.
52. The method as claimed in claim 49, further comprising steps of:
moving the third winding roller toward the nip between the first
winding roller and the second winding roller in a step of forming
the log; when the log is in contact with the fourth winding roller,
moving the third winding roller from the nip and arranging the
third winding roller in a position of cooperation with said
severing member.
53. The method as claimed in claim 47, wherein between the first
part of the winding cycle and the second part of the winding cycle,
an intermediate part of the winding cycle is carried out, wherein
the log being wound is in contact with the first winding roller,
the second winding roller, the third winding roller and the fourth
winding roller and moves across the nip between the first winding
roller and the second winding roller.
Description
TECHNICAL FIELD
[0001] The present invention relates to methods and machines for
producing logs of web material, in particular but not exclusively
logs of paper, in particular tissue paper, for example rolls of
toilet tissue, kitchen towels or the like.
STATE OF THE ART
[0002] In the field of paper manufacturing, in particular for the
production of rolls of toilet tissue, kitchen towels or the like,
large reels (parent reels) of tissue paper coming directly from the
continuous production machine are wound. These large reels are
subsequently unwound and rewound to produce rolls or logs with
smaller diameters, corresponding to the diameters of the end
product destined for the market. These logs have an axial length
equal to a multiple of the finished roll destined for distribution
and for sale and are subsequently cut by cutting machines to obtain
the end product destined to be packaged and subsequently
marketed.
[0003] To produce logs of web material, modern rewinding machines
provide for the use of winding rollers that, in various
combinations and arrangements, and with suitably controlled
rotation, allow logs to be produced automatically in rapid sequence
through continuous feed of the web material. At the end of winding
of a log, the log must be moved away from the winding area and the
web material must be severed (by cutting, tearing or the like), to
allow winding of a subsequent log to start. Normally, winding takes
place around winding cores, typically but not exclusively made of
cardboard, plastic or another similar suitable material. In some
cases, winding takes place around extractable and recyclable
mandrels, i.e. which are extracted from the completed log after
winding has been completed, to be reinserted into the rewinding
machine in order to wind a subsequent log.
[0004] In winding machines of more modern design, the winding
movement is imparted to the logs being formed by means of contact
with two or more rollers rotating at controlled speed. These
rewinding machines are called peripheral or surface rewinding
machines, as the winding movement is imparted peripherally through
the contact between the surface of the winding rollers and the
surface of the logs being formed. Examples of automatic continuous
surface rewinding machines of this type are disclosed in U.S. Pat.
No. 5,979,818 and in other patents of the same family, and in the
patent literature cited in this patent. An improvement to the
machine described in this US patent is described in
WO-A-2011/104737 and in WO2007/083336. In these prior art winding
machines, severing of the web material is performed by means of a
severing, tearing or cutting member, which cooperates with a fixed
axis winding roller, around which the web material is fed, and
which defines, together with a second winding roller, a nip for
inserting the winding cores into a winding cradle.
[0005] These machines are also defined as continuous and automatic,
as the various steps of the winding cycle of each log follow one
another automatically, passing from the production of one log to
the next, without interrupting the feed of the web material and at
an approximately constant or substantially constant speed. The term
automatic continuous rewinding machine is used in the present
description and in the appended claims to indicate this type of
machine.
[0006] One of the critical steps in automatic continuous peripheral
rewinding machines of the type described above consists in the
change-over step, i.e. the step of severing the web material,
discharging the completed log and starting to wind a new log around
a new winding core inserted into the winding cradle.
[0007] Various solutions have been studied to perform these
operations automatically and rapidly, for example through the use
of winding rollers rotating at controlled speed that accelerate
and/or decelerate in synchronism in order to favor correct movement
of the completed logs and of the new cores. In some cases, tearing
systems are provided, in which the web material is severed at the
end of winding by means of a difference in speed. In other cases,
pressurized air systems, suction systems, mechanical systems or the
like are used to perform severing of the web material.
[0008] WO-A-2012/042549 describes a peripheral automatic rewinding
machine with four rollers. The use of four rollers, all or at least
some with movable axes, allows two winding cradles to be defined
and more efficient control of the log being formed. In some
embodiments described in that document, the log being formed is
always in contact with at least three winding rollers and in some
cases it can be temporarily in contact with four winding rollers.
This allows particularly efficient control of the winding cycle, of
the shape of the log and of the winding density to be obtained. In
some embodiments the web material is severed by lengthening the
path of the web material between two winding rollers. Lengthening
causes the web material to break, forming the free trailing edge of
a complete log and a free leading edge to start winding the
subsequent log on a new core. Although this machine achieves
particularly appreciable results in terms of winding accuracy and
operating reliability, there are some aspects that could be further
improved. In particular, correct operation and reproducibility of
the winding cycle in some cases can depend on the properties of the
material being processed, i.e. of the web material and/or of the
winding cores.
SUMMARY OF THE INVENTION
[0009] According to the present disclosure, there is provided a
rewinding machine with four rollers, of automatic continuous
peripheral type, in which logs of web material are wound in rapid
sequence around winding cores, without interrupting the feed of the
web material, i.e. feeding the web material continuously or
substantially continuously to a winding head, which comprises, in
addition to the winding rollers, also a mechanism for severing of
the web material at the end of each winding cycle.
[0010] By continuous or substantially continuous feed it is
intended here that the web material has a feed speed that is
substantially independent from the winding cycle, it being
understood that other factors can, even substantially, modify the
feed speed of the web material. For example, when a parent reel
from which the web material is dispensed, must be replaced, or when
the web material breaks, it may be necessary to slow or even stop
feed of the web material to the winding head. However, this
variation of speed or stop is not correlated to the winding cycle
of the single logs.
[0011] According to one aspect, an automatic continuous peripheral
rewinding machine for producing logs of web material wound around
winding cores is provided, comprising a first winding cradle formed
between a first winding roller, a second winding roller and a third
winding roller. The first winding roller and the second winding
roller define a nip through which the winding cores with the web
material wound around them pass. The rewinding machine can also
comprise a winding cores feed path that extends between the first
winding roller and the third winding roller. Advantageously, a
second winding cradle is also provided, formed between the first
winding roller, the second winding roller and a fourth winding
roller. The third winding roller is positioned upstream of the nip
and the fourth winding roller is positioned downstream of the nip,
with respect to the direction of feed of the winding cores through
the nip. The rewinding machine can comprise a rolling surface for
the winding cores, extending partially around the first winding
roller toward the third winding roller. Between the rolling surface
and the first winding roller an insertion, i.e. feed, channel for
the winding cores is defined. In the rewinding machine there can be
defined a feed path for the web material which extends between the
first winding roller and the third winding roller and between the
first winding roller and the second winding roller. The rolling
surface is configured and arranged with respect to the first
winding roller so that the cores are fed by rolling in contact with
the rolling surface and with the web material driven around the
first winding roller.
[0012] In the context of the present description and of the
appended claims, coherently with the meaning given to this term in
the field of converting of paper and other endless web materials,
and in particular according to the terminology of rewinding machine
manufacturers, the term winding roller is intended as a motorized
roller, i.e. a roller which is rotated positively by means of a
motor, to transmit the winding movement to the log being formed by
friction between the surface of the winding roller and the log,
which contacts said winding roller.
[0013] The arrangement of the winding rollers is such as to allow,
for example, winding of the logs of web material by co-action
always of three winding rollers in contact with the log being
formed. Moreover, the particular arrangement of the third winding
roller with respect to the insertion path of the cores and of the
web material, which extends between the third winding roller and
the first winding roller, as well as through the nip between the
first winding roller and the second winding roller, which separates
the first winding cradle with respect to the second winding cradle,
can allow the winding rollers to be suitably dimensioned, to
process also winding cores of small diameter.
[0014] In advantageous embodiments, the rewinding machine comprises
a web material severing member configured and controlled to sever
the web material at the end of winding of a log in the second
winding cradle. For example, the severing member can be configured
and controlled to cooperate with the first winding roller.
[0015] In some embodiments, the severing member is configured and
controlled to pinch the web material against the first winding
roller and sever the web material by generating in the web material
a tension greater than the breaking point of the web material.
[0016] In some embodiments, the rolling surface extends from an
inlet of winding cores feed channel to the third winding roller. In
this way, the winding cores are inserted in the channel, fed by
rolling along said channel and around the first winding roller,
with the web material between the first winding roller and the
winding core being fed in the channel. The path of the winding
cores then continues, beyond the insertion channel, between the
first winding roller and the third winding roller, to reach the
first winding cradle.
[0017] In advantageous embodiments, the rolling surface has
interruptions through which a severing member can penetrate the
winding cores feed channel to pinch the web material against the
first winding roller. For example, the rolling surface can be
formed by a comb structure, comprising a plurality of shaped
laminar elements, spaced from one another. The shaped edges of the
laminar elements form the rolling surface for the cores. The space
between adjacent elements allows the passage of the severing
member. The severing member can comprise one or more pressers that
are interposed between laminar elements of the comb structure
forming the rolling surface.
[0018] In some embodiments, the rolling surface can be divided into
two portions. A first portion can be stationary with respect to a
load-bearing structure. A second portion, positioned downstream of
the first portion with respect to the direction of feed of the
winding cores along the insertion channel, can be movable together
with the third winding roller.
[0019] In possible embodiments, at least one of said first winding
roller and second winding roller has a movable axis, to control the
distance between the first winding roller and the second winding
roller and the dimension of the nip between the first winding
roller and the second winding roller. In some embodiments,
preferably both the first winding roller and the second winding
roller have a movable axis. The first winding roller and the second
winding roller can have axes that move symmetrically with respect
to a centerline plane passing through the nip formed between the
first winding roller and the second winding roller.
[0020] In other embodiments the first winding roller can have a
stationary axis while the second winding roller has a movable axis
to control the dimension of the nip between the first winding
roller and the second winding roller.
[0021] The diameters of the four winding rollers could be different
from one another. Preferably, it is advantageous for the first
winding roller to have a diameter larger than the second winding
roller.
[0022] In some embodiments the movement of the first, second, third
and fourth winding rollers during forming of the log is controlled
so that: a first part of winding of the log takes place with the
log in contact with the first winding roller, the second winding
roller and the third winding roller; a second part of winding of
the log takes place with the log in contact with the first winding
roller, the second winding roller, the third winding roller and the
fourth winding roller; a third part of winding of the log takes
place with the log in contact with the first winding roller, the
second winding roller and the fourth winding roller.
[0023] According to a further aspect, there is provided a method
for winding a web material and forming in sequence logs of said web
material wound around winding cores, comprising the steps of:
[0024] arranging four winding rollers defining a first winding
cradle between a first winding roller, a second winding roller and
a third winding roller, and a second winding cradle between said
first winding roller, the second winding roller and a fourth
winding roller;
[0025] arranging a rolling surface extending around the first
winding roller and forming therewith a feed channel for the winding
cores;
[0026] feeding the web material around the first winding
roller;
[0027] inserting a first winding core into the feed channel and
feeding said first winding core along an insertion path between the
first winding roller and the third winding roller and inserting the
first winding core into the first winding cradle;
[0028] carrying out a first part of a winding cycle of a first log
around a first winding core in the first winding cradle,
[0029] transferring the first log being formed from the first
winding cradle into the second winding cradle through a nip defined
between the first winding roller and the second winding roller;
[0030] carrying out a second part of a winding cycle of the first
log in the second winding cradle;
[0031] at the end of winding of the first log in the second winding
cradle, inserting a second winding core into the feed channel and
along the insertion path that extends between the first winding
roller and the third winding roller and inserting the second
winding core into the first winding cradle.
[0032] In some embodiments, the method can comprise the steps of
inserting the second winding core against the first winding roller
pinching the web material between the second winding core and the
first winding roller, and severing the web material between the
first log in the second winding cradle and the second winding
core.
[0033] The method can comprise the steps of: providing a web
material severing member; and acting through said severing member
on the web material to sever the web material thus generating a
trailing edge of the first log and a leading edge with which to
start winding a second log around the second winding core. The two
edges can be generated between the second core and the first log
nearing completion of winding.
[0034] In some embodiments, the method can comprise one or more of
the following steps of: arranging the rolling surface around the
first winding roller, defining an insertion channel for the winding
cores between the first winding roller and the rolling surface, the
rolling surface extending from an inlet of the insertion channel
for the winding cores to the third winding roller; inserting the
second winding core into the insertion channel and feeding the
second winding core by rolling along the insertion channel, in
contact with the rolling surface and with the web material driven
around the first winding roller, until reaching the third winding
roller; passing the second winding core between the first winding
roller and the third winding roller; inserting the second winding
core, with a second log being wound there around, into the first
winding cradle.
[0035] A possible embodiment of the method according to the
invention provides for the following steps:
[0036] a) inserting a first winding core toward the first winding
cradle, in contact with the web material entrained around the first
winding roller and in contact with the rolling surface;
[0037] b) fastening a leading edge of the web material to the first
winding core;
[0038] c) winding a part of a log of web material maintaining the
first winding core in the first winding cradle, and feeding the
first winding core toward the second winding cradle;
[0039] d) passing the first winding core, with the log being wound
there around, through the nip between the first winding roller and
the second winding roller and transferring the first winding core
with the log being formed there around into the second winding
cradle and completing winding of the log of web material in said
second winding cradle;
[0040] e) inserting a second winding core toward the first winding
cradle, in contact with the web material entrained around the first
winding roller and with the rolling surface;
[0041] f) severing the web material forming a leading edge of web
material, by means of the severing member and discharging the log
of web material from the second winding cradle;
[0042] g) repeating steps (b) to (f) to form a further log around
said second winding core, without interrupting the feed of the web
material.
[0043] A further embodiment of the method according to the
invention can comprise the following steps:
[0044] a) arranging the third winding roller in an initial position
for receiving a first winding core;
[0045] b) bringing a first winding core into contact with the web
material guided around the first winding roller and angularly
accelerating the first winding core moving it toward the first
winding cradle;
[0046] c) fastening a leading edge of the web material to the first
winding core;
[0047] d) feeding the first winding core between the first winding
roller and the third winding roller into the first winding cradle
and winding a part of a log of web material maintaining the first
winding core in the first winding cradle, and feeding the first
winding core toward the second winding cradle;
[0048] e) passing the first winding core, with the log being wound
there around, through the nip between the first winding roller and
the second winding roller, the third winding roller moving from the
initial position toward the nip between the first winding roller
and the second winding roller following the log being formed and in
movement in the first winding cradle and toward the second winding
cradle;
[0049] f) transferring the first winding core with the log being
formed there around into the second winding cradle
[0050] g) completing winding of the log of web material in the
second winding cradle;
[0051] h) returning the third winding roller to the initial
position;
[0052] i) bringing a second winding core into contact with the web
material entrained around the first winding roller;
[0053] j) severing the web material forming a leading edge of web
material, by means of the severing member with the third winding
roller in the initial position, and discharging the log of web
material from the second winding cradle;
[0054] k) repeating the steps (c) to (j) to form a further log
around said second winding core, without interrupting the feed of
the web material.
[0055] In yet a further embodiment, the method can comprise the
steps of:
[0056] arranging the rolling surface around the first winding
roller, forming with the first winding roller the feed channel of
the winding cores;
[0057] at the end of winding of a log, inserting a new winding core
into the feed channel in contact with the rolling surface and with
the web material entrained around the first winding roller,
angularly accelerating the winding core in the feed channel;
[0058] inserting the severing member into the feed channel,
downstream of the new winding core, causing breaking of the web
material between the new winding core and the log nearing
completion of winding in the second winding cradle.
BRIEF DESCRIPTION OF DRAWINGS
[0059] The invention will be better understood by following the
description and accompanying drawing, which shows non-limiting
practical embodiments of the invention. More specifically, in the
drawing: le
[0060] FIGS. 1 to 5 schematically show a first embodiment of a
rewinding machine according to the invention in an operating
sequence;
[0061] FIG. 6 shows a diagram of a system of motorized centers for
guiding the winding cores;
[0062] FIG. 7 shows a sectional view according to the line VII-VII
of FIG. 6;
[0063] FIG. 8 shows the position of the system of FIGS. 6 and 7
with respect to the cluster of the winding rollers; and
[0064] FIG. 9 shows a further embodiment of a rewinding machine
according to the present disclosure.
DETAILED DESCRIPTION OF EMBODIMENTS
[0065] FIGS. 1 to 5 show an embodiment of a continuous peripheral
rewinding machine according to the invention and an operating
sequence that shows in particular the change-over step, i.e. the
step of discharging a log, winding whereof has been completed, and
inserting a new winding core to start formation of a subsequent
log.
[0066] FIGS. 1 to 5 show the main elements of the rewinding
machine, limited to those necessary to understand the concepts on
which the invention is based and an operating mode of the machine.
Construction details, auxiliary units and further components, known
and/or that can be designed according to the prior art, are not
shown in the drawing or described in greater detail. Those skilled
in the art may provide these further components on the basis of
their experience and knowledge of the field of paper converting
machinery.
[0067] In brief, in the embodiment shown herein, the machine,
indicated as a whole with 2, comprises a first winding roller 1
with a rotation axis 1A, arranged side by side with a second
winding roller 3 having a rotation axis 3A. The axes 1A and 3A are
substantially parallel to each other. Between the two winding
rollers 1 and 3 there is defined a nip 5, through which there is
fed (at least during a part of the winding cycle of each log) a web
material N to be wound around winding cores A1, A2 around which
logs L1, L2 are formed. The path of the web material N extends
around the first winding roller 1, wrapping it partially, so that
the web material N is in contact with the cylindrical surface of
the winding roller 1 for a certain arc of contact, which can vary
during the winding cycle, as will be apparent from the description
of the winding process.
[0068] As will be apparent from the description herein below, the
winding cores also pass through the winding nip 5 during an
intermediate step of the winding cycle.
[0069] The winding cores A1, A2 are inserted into the machine
upstream of the nip 5, into a first winding cradle 6, formed by the
first winding roller 1, by the second winding roller 3 and by a
third winding roller 7. The reference 7A indicates the rotation
axis of the third winding roller 7, substantially parallel to the
axes 1A and 3A of the first winding roller 1 and of the second
winding roller 3, respectively.
[0070] Winding of web material N around the winding cores ends when
the winding cores are located in a second winding cradle 10
positioned downstream of the nip 5 with respect to the direction of
feed of the winding cores in the winding head formed by the winding
rollers. The second winding cradle is formed by the first winding
roller 1, by the second winding roller 3, and by a fourth winding
roller 8. The reference 8A indicates the rotation axis of the
fourth winding roller 8, which is substantially parallel to the
axes of the winding rollers 1, 3, 7. The reference 12 indicates a
pair of arms pivoted in 12A, which support the fourth winding
roller 8. The double arrow f12 indicates the pivoting movement,
i.e. the reciprocating rotation movement of the arm 12 and
consequently of the fourth winding roller 8. By moving around the
fulcrum 12A the winding roller 8 can move toward or away from the
nip 5 defined between the first winding roller 1 and the second
winding roller 3.
[0071] In other embodiments, the fourth winding roller 8 can be
carried by a system of slides moving on linear guides, instead of
by arms pivoted around a pivoting axis. Also in this case, the
translation movement along the linear guides allows the winding
roller 8 to move toward and away from the nip 5.
[0072] In the present description and in the appended claims, the
definition "upstream" and "downstream" in relation to the position
of the winding rollers refers to the direction of feed of the web
material and of the axis of the winding cores, unless otherwise
specified.
[0073] The third winding roller 7 is provided with a movement
toward and away from the winding nip 5. For this purpose, in some
embodiments the third winding roller 7 is supported by a pair of
arms 9 pivoted about an axis 9A to oscillate, i.e. rotate with a
reciprocating motion, according to the double arrow f9. In other
embodiments, not shown, the third winding roller 7 can be supported
by slides moving on linear guides, so as to follow, for example, a
trajectory of rectilinear motion.
[0074] Upstream of the winding nip 5, of the first winding roller 1
and of the second winding roller 3, a core feeder or inserter 11 is
arranged, which can be made in any suitable manner and inserts
single winding cores A1, A2 toward the first winding cradle, as
will be described in greater detail with reference to the sequence
of FIGS. 1 to 5.
[0075] The winding cores can come from a "corewinder", i.e. from a
machine for forming winding cores, associated with the converting
line of the web material N in which the rewinding machine 2 is
inserted, and not shown.
[0076] In some embodiments, the rewinding machine comprises a
rolling surface 19 for the winding cores. The rolling surface 19
can have a roughly cylindrical shape, approximately coaxial to the
first winding roller 1 with movable axis, when this is in the
position of FIG. 1. The rolling surface 19 can have a step 19G in
an intermediate position of its extension. The rolling surface 19
can be divided into a first portion 19A and into a second portion
19B, the first positioned upstream of the second, with respect to
the direction of feed of the web material N.
[0077] The rolling surface 19 and the cylindrical surface of the
first winding roller 1 form a feed channel 21 for the winding cores
A1, A2. When the first winding roller 1 is in the position of FIGS.
1 to 4, the height of the feed channel 21 for the winding cores can
be smaller in the first portion of the feed channel and larger in
the second portion of the feed channel 21. The purpose of this
variation of the height of the feed channel 21 is to facilitate the
start of a rolling motion of each new winding core A1, A2, inserted
in the feed channel 21 by the inserter or feeder 11, as will be
explained herein below. In particular, in the first portion of the
feed channel 21, the height of the feed channel, i.e. the distance
between winding roller 1 and rolling surface 19, can be smaller
than the diameter of the winding cores A1, A2.
[0078] In some embodiments, the rolling surface 19 is formed by a
comb structure, with a plurality of arched plates arranged
side-by-side with one another, between which free spaces are
formed. Through these free spaces between adjacent plates forming
the rolling surface 19 there can be inserted a severing member of
the web material N, indicated as a whole with 23. In some
embodiments, the comb structure forms the first part 19A of the
rolling surface and can be stationary, i.e. fixed with respect to a
supporting structure, not shown. In some embodiments, a second part
19B of the rolling surface can be formed by elements 19C that move
with the axis 7A of the third winding roller 7, following the
movement of this latter.
[0079] The elements 19C can also be plates forming a comb
structure.
[0080] In other embodiments, the surface 19B can be formed by a
single arched plate, which extends transversely with respect to the
feed movement of the web material, i.e. parallel to the axes of the
winding rollers 1, 3, 7.
[0081] In some embodiments, the severing member 23 comprises a
presser, for example including a plurality of presser members 24.
The severing member 23 can be provided with a reciprocating
rotational movement, about an axis 23A, approximately parallel to
the axes of the winding rollers 1, 3. Reference f23 indicates the
movement of the severing member 23. Each presser member can have a
pressing pad 24A. The pressing pad 24A can be made, for example, of
elastically yielding material preferably with a high coefficient of
friction, for example rubber.
[0082] In a manner synchronized with the movement of the other
members of the machine, as will be better illustrated herein below
with reference to an operating cycle, the severing member 23 is
pressed against the first winding roller 1 to pinch the web
material N between the pads 24A of the presser members 24 and the
surface of the first winding roller 1. This latter can have a
surface with annular bands having a high coefficient of friction
and annular bands having a low coefficient of friction. In this
context, the terms "high" and "low" are intended to indicate a
relative value of the coefficients of friction of the two series of
alternating annular bands. The bands with low coefficient of
friction can advantageously be arranged in the areas in which the
pads 24A of the presser members 24 press. In this way, when the web
material N is pinched against the first winding roller 1 by the
presser members 24, it tends to be stopped by the pads 24A and to
slide on the annular bands with low coefficient of friction of the
first winding roller 1.
[0083] FIG. 1 shows a final step of the winding cycle of a first
log L1. As shown in FIG. 1, during this step of the winding cycle
of a first log L1 around a first winding core A1 the log L1 is
located in the second winding cradle 10, in contact with the first
winding roller 1, the second winding roller 3 and the fourth
winding roller 8. The web material N is fed, according to the arrow
fN around the first winding roller 1, through the nip 5 between the
first winding roller 1 and the second winding roller 3 and is wound
on the log L1 being formed, which is rotated by the rollers 1, 3
and 8 and retained thereby in the winding cradle 10. Reference 27
indicates a guide roller for the web material N positioned upstream
of the winding head defined by the winding rollers 1, 3, 7 and
8.
[0084] Preferably, the feed speed of the web material N is
substantially constant. Substantially constant is intended as a
speed that varies slowly with respect to the winding speed and as a
consequence of factors that are independent from the operations
performed by the members of the winding head described above, which
are controlled so as to perform the winding cycle, discharge the
formed log, insert the new core and start winding a new log at a
constant feed speed of the web material toward the cluster of
winding rollers and in particular toward the first winding roller
1.
[0085] Durante winding of the log L1, outside the change-over step,
which forms a transitional step in the operation of the machine,
the peripheral speeds of the winding rollers 1, 3, 7 and 8 are
substantially the same as one another and the various winding
rollers all rotate in the same direction, as indicated by the
arrows in the drawing. In this case, substantially the same means
that the speed can vary limited to the needs to control the
compactness of winding and the tension of the web material N
between the winding roller 7 and the winding roller 8, for example
to offset the variation in tension that could be caused by the
movement of the center of the log being formed along the path
between the winding rollers.
[0086] In some embodiments, this difference between peripheral
speeds of the winding rollers can typically be comprised between
0.1 and 1% and preferably between 0.15 and 0.5%, for example
between 0.2 and 0.3%, it being understood that these values are
examples and are not limiting.
[0087] Moreover, the peripheral speeds can vary slightly to cause
the advancing movement of the log being formed, as clarified below,
in order for it to pass from the first winding cradle 6 to the
second winding cradle 10.
[0088] The winding cycle of the logs is as follows.
[0089] In FIG. 1 the log L1 in the winding cradle 10 formed by the
rollers 1, 3, 8 has practically been completed, with winding of the
required amount of web material N around the first winding core A1.
The quantity of wound web material can be determined by a winding
length. A second winding core A2 has been brought by the winding
cores feeder or inserter 11 at the inlet of the feed channel
21.
[0090] The reference C indicates a continuous line or a series of
dots of glue applied to the outer surface of the second winding
core A2.
[0091] FIG. 2 shows the start of the change-over step, i.e. of
discharge of the completed log L1 and insertion of the new winding
core A2 into the winding head formed by the rollers 1, 3, 7, 8.
[0092] The second winding core A2 is inserted by the winding cores
feeder or inserter 11 into the inlet of the feed channel 21 defined
between the first winding roller 1 and the rolling surface 19.
[0093] The position of the first winding roller 1 in this step of
the winding cycle is such that it is about coaxial to the generally
and approximately cylindrical rolling surface 19. The distance
between the portion 19A of the rolling surface 19 and the
cylindrical surface of the first winding roller 1 is slightly less
than the diameter of the winding core A2. In this way, the winding
core A2 entering the feed channel 21 is pressed against the rolling
surface 19 and against the web material N driven around the first
winding roller 1.
[0094] This pressure generates a friction force between the surface
of the winding core A2 and the rolling surface 19, and between the
surface of the winding core A2 and the web material N entrained
around the cylindrical surface of the first winding roller 1. This
ensures that, as a result of the rotation movement of the first
winding roller 1 and of feed of the web material N, the winding
core A2 accelerates angularly, starting to roll along the rolling
surface 19, pushed by the web material N and by the first winding
roller 1 against which the web material N is pressed.
[0095] Along the second portion 19B of the rolling surface 19, the
radial dimension of the feed channel 21 can increase gradually,
thus reducing deformation of the diameter of the winding core A2
and allowing winding of the web material N around it to start, with
consequent formation of turns of a new log.
[0096] The step 19G, if provided, can facilitate the initial
angular acceleration phase of the winding core A2.
[0097] Durante the rolling movement of the winding core A2 in the
feed channel 21, the line of glue C applied to the winding core A2
comes into contact with the web material N, causing adhesion of the
web material N to the winding core.
[0098] In this step of the winding cycle, breaking or severing of
the web material N also takes place by means of the severing member
23. This latter is made to pivot against the first winding roller
1, so as to pinch, with the pads 24A, the web material N against
the surface of the first winding roller 1. As the winding rollers
1, 3 and 8 continue to rotate winding the web material N on the log
L1, the web material is stretched between the log L1 and the pinch
point of the web material N against the first winding roller 1 by
the severing member 23.
[0099] When the tension exceeds the breaking point, for example at
a perforation line of the web material N, this latter breaks
generating a trailing edge Lf, which is wound on the log L1, and a
leading edge Li, which is wound on the new winding core A2. The
leading and trailing edges Li and Lf are schematically shown in
FIG. 3. In this embodiment of the winding method, when severing of
the web material N is performed, the winding core A2 passes through
the portion of smaller radial dimension of the insertion channel 21
of the winding cores A2, i.e. at the step 19G. In other
embodiments, severing of the web material N can take place before
or after passage of the winding core A2 over the step 19G.
[0100] In some embodiments, winding can start without the use of
glue C, for example by electrostatically charging the web material
N and/or the winding core A2, or using a suction system, optionally
inside the winding core A2, which can be provided with suction
holes. In other embodiments, winding can start with the aid of air
jets. In yet other embodiments, start of winding can be obtained or
facilitated through suitable control of the movement of the
severing member 23. For example, the severing member can be
controlled to form a loop of web material N, which is wound around
the winding core.
[0101] While in the sequence of FIGS. 1 to 5, the movement of the
severing member 23 is alternating reciprocating movement, in other
embodiments the movement of the severing member 23 can be always in
the same direction, for example clockwise in the drawing. The speed
of the severing member can be controlled so as to cause breaking or
severing of the web material between the pinch point of the web
material N by the pads 24A and the log L1, for example by rotating
the severing member 23 with a speed so that the pads 24A are fed at
a lower speed than the peripheral speed of the first winding roller
1. In other embodiments, the speed of the pads 24A can be greater
than the peripheral speed of the first winding roller 1. In this
case, breaking or severing of the web material N can take place
between the pinch point of the web material N by the pads 24A and
the pinch point of the web material N between the first winding
roller 1 and the new winding core A2.
[0102] In other embodiments, not shown, the severing member can be
configured differently, and perform, for example, cutting of the
web material, using a blade that cooperates with a counter-blade on
the first winding roller 1. In yet other embodiments, severing of
the web material can be obtained with a severing member housed in
the first winding roller 1 or between this latter and the path of
the web material N, the severing member being configured and
controlled to sever the web material acting from the side of the
web material N facing the winding roller 1.
[0103] FIG. 4 shows the subsequent step, in which the second
winding core A2, rolling along the rolling surface 19, leaves the
rolling surface 19 and comes into contact with the cylindrical
surface of the third winding roller 7, which is located at the end
of the insertion channel 21 for the winding cores.
[0104] The third winding roller 7 can be provided with a series of
annular grooves 7S, into which the ends of the plates that form the
terminal part 19B of the rolling surface 19 are inserted. In this
way, the winding core A2 is gently transferred from the rolling
surface 19 to the surface of the third winding roller 7.
[0105] Rolling on the surface of the third winding roller 7 and
remaining in contact with the web material N driven around the
first winding roller 1, the winding core A2, or more precisely the
new log L2 that starts to form there around, also comes into
contact with the second winding roller 3, as shown in FIG. 4.
Therefore, in practice the path of the winding cores extends
between the first winding roller 1 and the third winding roller 5
and through the nip 5 between the first winding roller 1 and the
second winding roller 3.
[0106] To allow feed of the winding core A2 along the feed channel
21, the severing member 23 is rotated around the axis 23A until it
exits from the feed channel 21. The glue C (or another means or
member for starting winding) has caused adhesion of the web
material N to the winding core A2, so that the web material starts
to wind on the winding core A2 starting the formation of a second
log L2 while the core is fed by rolling along the channel 21.
[0107] During the operations described above, the first log L1
starts the movement of ejection from the second winding cradle 10,
for example as a result of a variation of the peripheral speeds of
the rollers 1, 3 and 8. In some embodiments the fourth winding
roller 8 can be accelerated and/or the second winding roller 3 can
be decelerated to cause the log L1 to move away from the second
winding cradle 10 toward a discharge chute 31. The fourth winding
roller 8 moves upward to allow passage of the log L1 toward the
discharge chute 31.
[0108] In FIG. 4 the second winding core A2 is located in the first
winding cradle 6 and is in contact with the first winding roller 1,
the second winding roller 3 and the third winding roller 7 and the
second log L2 is being formed there around. The completed log L1 is
discharged on the chute 31. The second winding core A2 passes
through a nip or space defined between the first winding roller 1
and the third winding roller 7, before coming into contact with the
second winding roller 3. Subsequently, as described below, the
winding core A2 with the log L2 being formed there around also
passes through the nip 5 between the first winding roller 1 and the
second winding roller 3.
[0109] Forming of the second log L2 continues through feed of the
web material N around the new winding core A2 and consequent
increase of the diameter of the new log L2. The third winding
roller 7 can move due to the movement of the arms 9 around the
fulcrum or axis 9A, following the increase of diameter of the
second log L2. The portion 19B of the rolling surface 19 can follow
the movement of the third winding roller 7, so as not to obstruct
the movement of this latter toward the nip 5 between the first
winding roller 1 and the second winding roller 3.
[0110] After having performed a part of the winding cycle in the
cradle 6, the log L2 is moved to the second winding cradle 10 where
winding of the log is completed. For this purpose, it is necessary
to pass the log L2 through the nip 5. To do this, in some
embodiments one or preferably both the winding rollers 1 and 3 can
be supported by respective arms 1B, 3B such as to pivot around axes
of oscillation 1C, 3C.
[0111] As can be seen in FIG. 5, which shows an intermediate step
of the passage from the winding cradle 6 to the winding cradle 10,
the distance between centers of the winding rollers 1 and 3 is
gradually increased, for example by pivoting the arms 1B, 3B. In
other embodiments, the winding rollers 1, 3 can be carried by
slides provided with a translation movement, instead of a pivoting
or rotation movement.
[0112] Whatever the mechanism used to modify the distance between
centers of the winding rollers 1 and 3, their movement away from
each other (FIG. 5) allows the log L2 to pass through the nip 5 and
enter the winding cradle 10.
[0113] In some embodiments, during this step the third winding
roller 7 can move gradually toward the second winding cradle 10,
accompanying the log L2. In this way, winding continues to take
place in contact with at least three winding rollers 1, 3, 7.
[0114] The fourth winding roller 8, which was raised to allow
growing of the log L1 followed by discharge thereof toward the
chute 31, is returned toward the nip 5 until it comes into contact
with the log L2, which is fed through the nip 5. For a part of the
winding cycle the log L2 can be in contact with all four winding
rollers 1, 3, 7 and 8.
[0115] The third winding roller 7 can move toward the nip 5
following the log L2 until it is made to pass beyond the nip
between the rollers 1 and 3. From this point on, the log L2 can be
in contact only with the rollers 1, 3 and 8 and finish being wound
in the second winding cradle 10.
[0116] The feed movement of the axis of the log L2 can be suitably
obtained with a control of the movement of the winding rollers,
which by modifying the mutual position of their axes, move the log
L2 into the, and through the, area of minimum distance between the
rollers 1 and 3. For example, movement can be obtained by pushing
the log with the third winding roller 7. In some embodiments the
movement of the log can be facilitated, supported or influenced
through temporary variation of the peripheral speeds of the winding
rollers, for example by decreasing the peripheral speed of the
second winding roller 3 for a short time.
[0117] While the embodiment shown in FIG. 5 includes a step in
which the log L2 is in contact with the four winding rollers 1, 3,
7 and 8, in other embodiments the third winding roller 7 could lose
contact with the log L2 before it passes through the nip 5, beyond
the point of minimum distance between the winding rollers 1 and 3,
and comes into contact with the fourth winding roller 8. However,
in the embodiment shown, better control of the log is obtained in
the various steps of formation, as the log is always in contact
with at least three winding rollers.
[0118] The time for which the second winding core A2 remains in the
position of FIG. 5, i.e. in the winding cradle 6, can be controlled
simply by acting on the peripheral speed of the winding rollers 1,
3 and 7 and/or on the position of the rollers. The second winding
core A2 will remain substantially in this position, without being
fed further, for the whole of the time in which the peripheral
speeds of the winding rollers 1, 3 and 7 remain the same as one
another. As mentioned above, subsequent advancement is obtained,
for example, by decelerating the second winding roller 3. It is
thus possible to set the amount of web material N that is wound
around the winding core A2 as desired, retaining this latter and
the second log L2 that is formed there around in the winding cradle
1, 3, 7 for the desired time.
[0119] Once the log L2 is located in the second winding cradle 10,
winding of the second log L2 continues until reaching the condition
of FIG. 1. The third winding roller 7, which can be moved toward
the nip 5 to accompany the movement of the log L2 through the nip
in the second winding cradle 10, can return to the initial position
of FIG. 1, in which it cooperates with the severing member 23.
[0120] In some embodiments, the structure of the members of the
rewinding machine is such that the path followed by the center of
the winding cores A1, A2 from the time in which they come into
contact with the three winding rollers 1, 3 and 7 to the time in
which the log starts to be discharged between the rollers 1, 3 and
8, losing contact with the winding roller 7, is substantially
rectilinear. This allows more regular winding and facilitates the
use of centers that can be inserted into the opposed ends of the
winding cores in order to improve control of the rotation and feed
movement of the core and of the log during the winding cycle,
combining the peripheral winding technique with an axial or central
winding, as described, for example, in the U.S. Pat. No. 7,775,476
and in the publication US-A-2007/0176039.
[0121] With the described arrangement of the four winding rollers
and the path of the winding cores between the first winding roller
1 and the third winding roller 7, it is possible to provide the
first and the second winding roller 1, 3 with relatively large
diameter, and such that an intermediate support is not required,
even when the winding cores have a small diameter. Control of the
winding cores of small diameter is nonetheless guaranteed also with
winding rollers 1, 3 of relatively large diameter, as the third
winding roller 7 can be provided with a smaller diameter. The lower
flexural rigidity of the third winding roller 7 due to the smaller
diameter of this roller can be offset using one or more
intermediate supports. In some embodiments, the third winding
roller 7 can be associated with a supporting and stiffening beam,
which extends parallel to the axis 7A of the third winding roller
7, in an area in which this beam does not interfere with the path
of the web material N and with the logs L1, L2 being formed. The
beam can be positioned, for example, at the elements 19C, or in a
diametrically opposite position with respect thereto, i.e. in an
area in which the third winding roller 7 does not cooperate with
the web material N and/or with the log L1, L2 being formed.
[0122] In the embodiment shown in the accompanying figures, the
first winding roller 1 and the second winding roller 3 have
substantially the same diameter and are both mounted with movable
axes to increase and decrease the dimension of the nip 5, through
which the logs being formed around the respective winding cores
pass. In other embodiments, the winding roller 1 can be provided
with a different diameter, for example larger than the winding
roller 3. By increasing the diameter of the winding roller the
support system of said roller can be simplified, as a larger
diametrical dimension implies greater flexural rigidity.
[0123] Moreover, in some embodiments, only one of the two winding
rollers 1 and 3 can have a movable axis, while the other has a
fixed axis. In this way, the number of actuators required for
movement of the various members of the rewinder is reduced and the
law for controlling the motion of the winding rollers is
simplified. If the two winding rollers 1 and 3 have different
diameters, it is advantageous for the winding roller of larger
diameter, for example the winding roller 1, to have a fixed axis,
while the winding roller of smaller diameter has a movable axis. In
this configuration the winding sequence of the web material around
the winding core does not change. Winding starts in the winding
cradle 6 and ends, after passage of the log being wound through the
nip 5, in the second winding cradle 10.
[0124] In yet further embodiments, the winding rollers 1 and 3 can
both be movable, but can carry out asymmetrical movements.
[0125] In some embodiments, the rewinding machine described above
can be provided with a system of motorized centers, which engage,
guide and control the winding cores during at least a part of their
travel between the winding cradle 6 defined by the rollers 1, 3 and
7, upstream of the nip 5, and the winding cradle 10 formed by the
rollers 1, 3 and 8, downstream of the nip 5.
[0126] The system of centers can comprise, on each side or side
member of the machine, a center 101 for engaging the respective end
of a winding core A1, A2 that is inserted into the winding area.
FIGS. 6 and 7 show one of these centers and the related operating
mechanism.
[0127] The center 101 can have a rod 103 that ends with a head 105.
The head 105 can have a mechanism to engage the tubular winding
core. In some embodiments, the head 105 can engage with the winding
core by being inserted therein. The head 105 can have expansible
members, to torsionally engage the winding core. In some
embodiments, the expansible members comprise expansible annular
members 107, for example pneumatically expansible, through a
compressed air feed system. The compressed air can be conveyed
through ducts 109.
[0128] The center 101 can be provided with a translation movement
according to arrow f101, parallel to the longitudinal axis X-X of
the center.
[0129] An actuator, for example a piston-cylinder actuator 111, can
be used to control the reciprocating translation movement according
to the double arrow f101. This movement allows the heads 105 of
opposed centers 101 on the two sides of the machine to be moved
toward each other, until the heads 105 engage with the ends of the
respective winding core A1, A2 that is located in the winding area.
The heads 105 can be made to partially or totally penetrate the
ends of the winding core.
[0130] As can be seen in particular in FIG. 6, each center 101 can
be provided with a motor 115, for example an electronically
controlled electric motor, which rotates the respective center 101
around its axis X-X. The motion can be transmitted from the motor
115 to the center 101 by means of a belt 117, for example a toothed
belt. The toothed belt 117 can be driven around a pulley 119
torsionally constrained to the rod 103 of the respective center
101. More in particular, the pulley 119 can be fitted onto a sleeve
121, inside which the rod 103 of the center 101 can slide according
to the double arrow f101, the sleeve 121 being torsionally coupled
to the rod 103, for example through a grooved profile or the like.
The sleeve 121 can be supported by means of bearings 123 inside a
bushing 125 that can be carried by a slide 127.
[0131] The slide 127 can be mounted on stationary guides 129, i.e.
integral with the load-bearing structure of the rewinding machine.
In this way, the slide 127 can be translated according to the
double arrow f127 in the direction defined by the guides 129. In
some embodiments the rectilinear alternating movement according to
f127 can be imparted by a motor 131, for example an electronically
controlled electric motor. The electric motor 131 can cause the
oscillation of a crank 133, wherefrom motion is transmitted through
a connecting rod 135 to the slide 127, the connecting rod 135 being
hinged in 135A to the slide 127 and in 135B to the crank 133.
[0132] The movement according to the double arrow f127 can be
substantially rectilinear and parallel to the movement of the
center of the winding core A1, A2 when this passes from one to the
other of the two winding cradles definite by the sets of three
rollers 1, 3, 7 and 1, 3, 8, during the winding process described
above. The centers 101 can engage with the winding core A1, A2 when
this is in the winding cradle 6 upstream of the nip 5 and can
disengage therefrom when the log L1 is almost finished, thus
allowing discharge of this latter according to the description
above with specific reference to the step shown in FIGS. 3 and
4.
[0133] During the movement according to the double arrow f127, and
more in particular during the step of upward movement (in the
figure) of the centers 101, these accompany the winding core while
the log L1 grows in diameter, while the motor 115 imparts, by means
of the belt 117, a rotation movement to the centers 101, which is
transmitted to the winding core and therefore to the log being
formed, as a result of torsional coupling between the heads 105 of
the centers 101 and the winding core A1, A2. The rotation speed
imparted by the motor 115 can be controlled, so as to be coherent
with the peripheral speed of the log L1 being wound.
[0134] The use of the centers 101 allows better control of winding
and of the advancement of the log L1 from one to the other of the
two winding cradles 6, 10 and through the nip 5 during all steps of
the winding cycle.
[0135] In the embodiments shown in FIGS. 1 to 8, the first winding
roller 1 and the second winding roller 3 have substantially the
same diameter and can both have a movable axis, to favor passage of
the core and of the web in the first winding step from the first
winding cradle 6 to the second winding cradle 10. In other
embodiments, the first winding roller 1 and the second winding
roller 3 can have different diameters and preferably the first
winding roller 1 can have a larger diameter than the second winding
roller 3.
[0136] In possible embodiments, one of the winding rollers 1 and 3
can have a fixed axis and the other a movable axis.
[0137] Preferably, the first winding roller 1, around which the web
material N is wound and guided, can have a fixed axis and have a
larger diameter than the second winding roller 3.
[0138] FIG. 9 shows a configuration of this type. The same numbers
indicate the same or equivalent parts to those described with
reference to FIGS. 1 to 8. In particular, the four winding rollers
are indicated with 1, 3, 7 and 8. Around the first winding roller 1
there is formed a channel 21 for insertion of the winding cores A1,
A2. The channel is delimited by the cylindrical surface of the
first winding roller 1 and by a rolling surface 19 that extends
around the first winding roller 1 and toward the third winding
roller 7. The winding cores are inserted into the channel 21 so as
to be in contact with the rolling surface 19 and with the web
material N entrained around the first winding roller 1. The rolling
surface 19 can have a sort of intermediate step, as indicated in
19G, to facilitate angular acceleration of the winding core and
gripping of the web material after severing caused, in the same way
as already described above, by means of a severing member 23 of the
web material N. This severing member 23 of the web material
cooperates with the first winding roller 1 pinching the web
material between the first winding roller and one or more pressers
24A carried by the severing member 23.
[0139] The rotation axis 1A of the first winding roller 1 is
stationary with respect to the load-bearing structure of the
machine 1, so as to make feed of the web material N up to the nip 5
between the first winding roller 1 and the second winding roller 3
more stable and more easily controlled.
[0140] In this embodiment the second winding roller 3 has a
diameter substantially smaller than the diameter of the first
winding roller 1. For example, the diameter of the second winding
roller 3 can be less than half the diameter of the first winding
roller 1. The second winding roller 3 can be supported by lateral
side members 4, as indicated schematically in FIG. 9. Between the
lateral side members 4 intermediate supports can be arranged, which
support the second winding roller 3 in intermediate positions
between the ends of this latter. In this way, it is possible to
design the second winding roller 3 with a small diameter
[0141] To obtain sufficient rigidity of the second winding roller
3, the side members 4 and any intermediate supports can be
constrained to a transverse beam 14.
[0142] The axis 3A of the second winding roller 3 can be movable
and pivot around a pivoting axis defined by a pivot point 16 of the
side members 4 to the load bearing structure of the rewinding
machine 2. The pivoting movement of the second winding roller 3 can
be controlled by a motor 18 associated with a crank 20. A
connecting rod, also pivoted in 22B to the respective side member
4, can be pivoted in 22A to the crank 20. The reciprocating
rotation movement of the motor 18 pivots the axis 3A of the second
winding roller 3 around the axis defined by the pivot point 16. In
some embodiments, two symmetrical motors 18 can be provided, to act
on two opposed side members 4. Between the side members 4 there can
be fixed the chute 31, or a part thereof, so that said chute 31 can
follow the movement of the second winding roller 3.
[0143] The third winding roller 7 is carried by side members 32
constrained to a transverse beam 34 and pivoted in a pivot point 36
to the stationary structure of the rewinding machine 2.
Intermediate supports can be integral with the transverse beam 34
to support the third winding roller 7 in intermediate points
between the two ends thereof, supported by the side members 32.
Pivoting of the third winding roller 7, i.e. the translation
movement of its rotation axis 7A to follow the movement of the
winding cores and of the logs being formed, can be imparted by a
motor 42 by means of a connecting rod-crank system 44, 46
constrained to the transverse beam 34 in 46A.
[0144] A portion 19C of the rolling surface 19 can be constrained
to the side members 32, which portion in this way can follow the
translation movement of the third winding roller 7 during the
various steps of the winding cycle.
[0145] The operating sequence of the machine 2 of FIG. 9 is
substantially the same as the one described with reference to FIGS.
1 to 5 and therefore will not be described in detail. FIG. 9 shows
a completed log L1, ready to be discharged from the second winding
cradle 10, and a second winding core A2 already inserted into the
first winding cradle 6, between the winding rollers 1, 3, 7. The
operating condition shown in FIG. 9 can actually occur in the
machine, but this is not indispensible. Depending on the type of
regulation, the case in which the second winding core A2 reaches
the position of FIG. 9 when the log L1 has already been ejected
from the second winding cradle 10 can also occur.
[0146] The passage of the second winding core A2, with the log
being formed there around, through the nip 5 defined by the first
winding roller 1 and by the second winding roller 3 is allowed or
facilitated by moving only the axis 3A of the second winding roller
3, while the axis 1A of the first winding roller 1 remains
stationary with respect to the structure of the machine. In this
way, the operation of the rewinding machine is made more uniform,
in particular as the path of the winding material upstream of the
nip 5 is not modified.
[0147] A further advantage of the embodiment of FIG. 9 consists in
that operation of the severing member 23 of the web material N is
simplified. In fact, it co-acts with a winding roller 1, whose
rotation axis does not move and therefore control of the severing
step of the web material N is simplified.
[0148] The use of a first winding roller 1 of larger diameter makes
it possible to avoid the need for an intermediate support of the
first winding roller 1, simplifying the structure of the machine
and improving the quality of the logs.
* * * * *