U.S. patent application number 09/809553 was filed with the patent office on 2001-08-02 for modular packaging machine with web tension control.
This patent application is currently assigned to Klockner-Bartelt, Inc.. Invention is credited to Brooker, Thomas E., Conn, Gregory A., Todd, James E..
Application Number | 20010010142 09/809553 |
Document ID | / |
Family ID | 22680602 |
Filed Date | 2001-08-02 |
United States Patent
Application |
20010010142 |
Kind Code |
A1 |
Todd, James E. ; et
al. |
August 2, 2001 |
Modular packaging machine with web tension control
Abstract
A packaging machine for forming pouches from a web of material
having web tension control. A second pair of infeed rolls allows
web tension through a sealing section to be controlled. An unwind
reel is power-driven according to downstream web demand to thereby
minimize tension spikes through the infeed section. The power
unwind further minimizes the amount of festoon area needed. An
entire packaging machine may be provided using modules. The
registration-related operations of each section are independently
controlled so that each module need only coordinate input and/or
output speeds with interfacing sections.
Inventors: |
Todd, James E.; (Sarasota,
FL) ; Brooker, Thomas E.; (Sarasota, FL) ;
Conn, Gregory A.; (Sarasota, FL) |
Correspondence
Address: |
LEYDIG VOIT & MAYER, LTD
6815 WEAVER ROAD
ROCKFORD
IL
61114-8018
US
|
Assignee: |
Klockner-Bartelt, Inc.
5501 N. Washington Blvd.
Sarasota
FL
34243
|
Family ID: |
22680602 |
Appl. No.: |
09/809553 |
Filed: |
March 15, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09809553 |
Mar 15, 2001 |
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09185343 |
Nov 3, 1998 |
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6247293 |
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Current U.S.
Class: |
53/64 ;
53/562 |
Current CPC
Class: |
B29C 65/18 20130101;
B31B 70/00 20170801; B65B 51/30 20130101; B29C 66/8181 20130101;
B29C 66/91421 20130101; B31B 70/10 20170801; B29C 66/932 20130101;
B31B 2155/001 20170801; B65B 1/02 20130101; B29C 66/83543 20130101;
B31B 2160/10 20170801; B29C 2793/009 20130101; B29C 66/0342
20130101; B29C 66/1122 20130101; B29C 66/43121 20130101; B29C 66/71
20130101; B29C 65/7861 20130101; B31B 2160/106 20170801; B29C
66/961 20130101; B65B 41/16 20130101; B31B 2155/0014 20170801; B29C
65/305 20130101; B31B 2155/00 20170801; B31B 70/005 20170801; B29C
66/98 20130101; B29C 65/14 20130101; B29C 66/3452 20130101; B29C
66/91431 20130101; B65B 9/093 20130101; B29C 53/48 20130101; B29C
66/849 20130101; B29C 66/93431 20130101; B29C 66/93441 20130101;
B29C 66/431 20130101; B29C 66/8511 20130101; B29C 66/71 20130101;
B29K 2023/12 20130101; B29C 66/71 20130101; B29K 2023/06
20130101 |
Class at
Publication: |
53/64 ;
53/562 |
International
Class: |
B65B 043/04; B65B
057/04 |
Claims
What is claimed is:
1. Apparatus for forming pouches from a web of sealable material
provided as a roll, the web traveling along a predetermined path,
the apparatus comprising: a pair of infeed rolls on the web path
and positioned to controllably draw the web from a supply, a
variable speed motor drivingly connected to the infeed rolls; a
seal station located downstream of the infeed rolls for forming
seals in the web; a pair of drive rolls on the web path downstream
of the seal station, the drive rolls positioned to controllably
draw the web from the infeed rolls, a variable speed motor
drivingly connected to the drive rolls; and a controller for
controlling the speed of the infeed roll and drive roll motors to
produce a predetermined positive draw rate of the web through the
seal station thereby to control web tension therethrough.
2. The pouch apparatus of claim 1 further comprising an unwind reel
upstream of the infeed rolls and supporting the roll, a variable
speed motor drivingly connected to the reel, a plurality of rollers
between the reel and the infeed rolls positioned in a pattern to
form a web festoon, at least one of the rolls being mounted for
translation to allow a buffer length of web to be accumulated in or
played out from the festoon, a sensor for measuring the buffer
length and operatively connected to the controller for increasing
reel motor speed as the buffer length decreases and decreasing reel
motor speed as the buffer length increases.
3. Apparatus for forming pouches from a web of material supplied as
a roll, the web traveling along a predetermined path, the apparatus
comprising: an unwind reel for supporting a roll of web material, a
variable speed motor drivingly connected to the reel; a pair of
feed rolls on the web path at a first point and positioned to
controllably draw the web from the reel, a variable speed motor
drivingly connected to the feed rolls; a plurality of rollers
between the reel and the feed rolls positioned in a pattern to form
a web festoon, at least one of the rolls being mounted for
translation to allow a buffer length of web to be accumulated in or
played out from the festoon, a sensor for measuring the buffer
length; and a controller for controlling speed of the reel motor,
the sensor operatively connected to the controller for increasing
reel motor speed as the buffer length decreases and decreasing reel
motor speed as the buffer length increases.
4. The pouch apparatus of claim 3 further comprising a seal station
located downstream of the rollers for forming seals in the web, the
feed rolls located downstream of the seal station.
5. The pouch apparatus of claim 3 further comprising a seal station
located downstream of the rollers for forming seals in the web, the
feed rolls located upstream of the seal station.
6. In a machine for forming pouches from a continuous web of
material supplied as a roll, and in which a web sealing section
draws the web from an unwind section, the web advancing at an
average velocity through the web sealing section, the improvement
comprising the unwind section having an unwind reel for supporting
the roll, a variable speed motor drivingly connected to the reel, a
controller for controlling speed of the reel motor to supply the
web at an average velocity of the web sealing section, a festoon
between the reel and the web sealing section for storing a buffer
of web material therebetween, a buffer monitor measuring the size
of the buffer and being operatively connected to the controller for
increasing the reel motor speed as the buffer size decreases and
decreasing the reel motor speed as the buffer size increases.
7. The improvement of claim 6 in which the web sealing section
draws the web from the unwind section in intermittent increments,
and wherein the buffer monitor performs a controlled cycle in which
the reel motor speed is increased and decreased for each
intermittent increment of web withdrawal by the web sealing
section.
8. The improvement of claim 6 in which the web sealing section
continuously withdraws the web from the unwind section at the
average velocity, and wherein the buffer size remains substantially
constant so that the controller drives the reel motor at a
substantially constant speed.
9. A modular pouch making apparatus for forming pouches from a
wound roll of planar material, the apparatus comprising: a supply
module adapted to receive an end of the planar material, a pair of
infeed rolls adapted to pull the planar material therethrough, a
variable speed motor drivingly connected to the infeed rolls, a
drive connected to the motor for adjusting the speed of the motor,
and a plow upstream of the infeed rolls for folding the material
into mating first and second sides; a sealing module downstream of
the supply module having a pair of drive rolls adapted to pull the
folded material therethrough, a variable speed motor drivingly
connected to the drive rolls, a drive connected to the motor for
adjusting the speed of the motor, a longitudinally adjustable
mechanism for making seals between the first and second sides at
spaced locations, and a cutter downstream of the drive rolls for
cutting the material at the seals; a filling module having an
endless carrier with a plurality of clamp pairs mounted thereon and
adapted to grip the individual pouches, a variable speed motor
drivingly connected to the endless carrier, a drive connected to
the motor for adjusting the speed of the motor, a device for
transferring the pouches from the cutter to the clamp pairs, a
variable speed motor drivingly connected to the transfer device, a
drive connected to the motor for adjusting the speed of the motor,
a mechanism for opening and closing the pouches before and after
filling, respectively, and a device for sealing the pouches after
the pouches are closed; and a controller connected to the drives
for adjusting speeds of the motors.
10. The pouch apparatus of claim 9 in which the supply module
further comprises a festoon between the reel and the infeed rolls
for storing a buffer length of planar material therebetween.
11. The pouch apparatus of claim 9 in which the supply module
further comprises a reel for supporting the roll of wound
material.
12. The pouch apparatus of claim 11 in which a variable speed motor
is drivingly connected to the reel, the controller adjusting the
speed of the reel motor.
13. The pouch apparatus of claim 9 in which the seal mechanism of
the sealing module comprises a carriage moveable in the
longitudinal direction, the carriage supporting a pair of seal bars
adapted to engage opposite sides of the folded material.
14. The pouch apparatus of claim 13 in which the planar material
has registration marks thereon, the apparatus further comprising a
variable speed motor drivingly connected to the carriage, a drive
connected to the motor for adjusting the speed of the motor, and a
sensor for sensing the registration marks and delivering a location
signal, the controller adapted to receive the location signals from
the sensor and adjust the position of the carriage based on the
location signals.
15. The pouch apparatus of claim 9 in which the planar material has
registration marks thereon, and in which the cutter comprises
cutter rolls, the apparatus further comprising a variable speed
motor drivingly connected to the cutter rolls, a drive connected to
the motor for adjusting the speed of the motor, and a sensor for
sensing the registration marks and delivering a cut signal, the
controller adapted to trigger rotation of the cutter rolls in
response to the cut signal.
16. The pouch apparatus of claim 9 in which the supply module
further comprises a sensor for sensing speed of the infeed roll
motor, the controller adapted to receive a speed signal from the
infeed sensor to thereby adjust infeed roll motor speed.
17. The pouch apparatus of claim 9 in which the sealing module
further comprises a sensor for sensing speed of the drive roll
motor, the controller adapted to receive a speed signal from the
drive roll sensor to thereby adjust drive roll motor speed.
18. The pouch apparatus of claim 9 in which the filling module
further comprises a sensor for sensing speed of the carrier motor,
the controller adapted to receive a speed signal from the carrier
motor sensor to thereby adjust carrier motor speed.
19. The pouch apparatus of claim 9 in which the filling module
further comprises a sensor for sensing speed of the transfer device
motor, the controller adapted to receive a speed signal from the
transfer device motor to thereby adjust carrier motor speed.
20. The pouch apparatus of claim 9 in which the planar material has
registration marks thereon, the supply module further comprising a
sensor for sensing the registration marks, the controller adapted
to receive signals from the registration mark sensor to thereby
adjust infeed roll speed.
21. The pouch apparatus of claim 9 in which the mechanism for
opening and closing the pouches comprises a pouch opening device
located upstream of a pouch filler and a separate pouch closing
device located downstream of the pouch filler.
22. The pouch apparatus of claim 9 in which the transfer device of
the filling module comprises a vacuum belt.
23. The pouch apparatus of claim 9 in which the seal device of the
filling module comprises radiant seal bars.
24. A supply module for a pouch making apparatus of the type which
forms pouches from a continuous web of wound material, the supply
module transforming the web from a single planar material to a
folded material having first and second mating sides, the supply
module comprising: a plow adapted to receive the planar material
and fold the material into the first and second mating sides; a
pair of infeed rolls disposed downstream of the plow, the infeed
rolls adapted to pull the material over the plow; a variable speed
motor drivingly connected to the infeed rolls; and a drive
connected to the motor for adjusting the speed of the motor.
25. The supply module of claim 24 further comprising a festoon
between the reel and the infeed rolls for storing a buffer length
of planar material therebetween.
26. The supply module of claim 24 further comprising a reel for
supporting the roll of wound material.
27. The supply module of claim 24 in which a variable speed motor
is drivingly connected to the reel, a drive connected to the motor
for adjusting the speed of the motor.
28. The supply module of claim 24 further comprising a sensor for
sensing speed of the infeed roll motor, the sensor adapted to
generate a signal corresponding to the infeed roll speed.
29. The supply module of claim 24 in which the planar material has
registration marks thereon, the supply module further comprising a
sensor for sensing the registration marks, the sensor adapted to
generate signals corresponding to the location of the registration
marks.
30. A sealing module for a pouch making apparatus of the type which
forms pouches from a continuous web of wound material, the sealing
module receiving a web of material folded to have first and second
mating sides, the sealing module comprising: a pair of drive rolls
adapted to pull the folded web material therethrough; a variable
speed motor drivingly connected to the drive rolls; a drive
connected to the motor for adjusting the speed of the motor; a
longitudinally adjustable mechanism for making seals between the
first and second sides at spaced locations; and a cutter downstream
of the drive rolls adapted to cut the material into individual
pouches at the seals formed by the sealing mechanism.
31. The sealing module of claim 30 in which the seal mechanism of
the sealing module comprises a carriage moveable in the
longitudinal direction, the carriage supporting a pair of seal bars
adapted to engage opposite sides of the folded material.
32. The sealing module of claim 31 in which the planar material has
registration marks thereon, the apparatus further comprising a
variable speed motor drivingly connected to the carriage, a drive
connected to the motor for adjusting the speed of the motor, and a
sensor for sensing the registration marks and delivering a location
signal.
33. The sealing module of claim 30 in which the planar material has
registration marks thereon, and in which the cutter comprises
cutter rolls, the apparatus further comprising a variable speed
motor drivingly connected to the cutter rolls, a drive connected to
the motor for adjusting the speed of the motor, and a sensor for
sensing the registration marks and delivering a cut signal.
34. The sealing module of claim 30 further comprising a sensor for
sensing speed of the drive roll motor, the sensor adapted to
generate a signal corresponding to the speed of the drive
rolls.
35. A filling module for a pouch making apparatus of the type which
forms pouches from a continuous web of wound material, the filling
module adapted to receive individual pouches, the filling module
comprising: an endless carrier; a variable speed motor drivingly
connected to the endless carrier; a drive connected to the carrier
motor for adjusting the speed of the carrier motor; a plurality of
clamp pairs mounted on the endless carrier, the clamp pairs adapted
to grip the pouches; a transfer device to feed the pouches to the
plurality of clamp pairs; a variable speed motor drivingly
connected to the transfer device; a drive connected to the transfer
motor for adjusting the speed of the transfer motor; a mechanism
for opening and closing the pouches before and after filling,
respectively; and a device for sealing the pouches after the
pouches are closed.
36. The filling module of claim 35 further comprising a sensor for
sensing speed of the carrier motor, the sensor adapted to generate
a signal corresponding to the speed of the carrier motor.
37. The filling module of claim 35 further comprising a sensor for
sensing speed of the transfer device motor, the sensor adapted to
generate a signal corresponding to the transfer device motor
speed.
38. The filling module of claim 35 in which the mechanism for
opening and closing the pouches comprises a pouch opening device
located upstream of a pouch filler and a separate pouch closing
device located downstream of the pouch filler.
39. The filling module of claim 35 in which the transfer device
comprises a vacuum belt.
40. The filling module of claim 35 in which the seal device
comprises a pair of radiant seal bars disposed on opposite sides of
the pouches.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to packaging machines, and
more particularly relates to horizontal form, fill, and seal
packaging machines.
BACKGROUND OF THE INVENTION
[0002] Packaging machines are generally known in which a continuous
web of material is converted into a plurality of individual
pouches. The continuous web of material is folded in half over a
plow to form two continuous side panels joined by a bottom fold.
The folded web is passed through a series of seal bars which form
transverse seals in between the side panels, thereby forming a
strip of pouches interconnected by transverse seals. A cutter cuts
through each transverse seal to form individual pouches with
unsealed top edges. The individual pouches are transferred to a
pouch filler, filled with product, and sealed. The sealed pouches
are then collected for transport. Machines of this type may be
categorized as either horizontal or vertical machines, depending on
the general direction of web travel. The present invention relates
to horizontal packaging machines in which the web travels
horizontally.
[0003] The type and volume of product being packaged often
determines whether the packaging process should use a continuously
or intermittently advancing web. Certain products, such as hard
candy, require a fill based on weight instead of volume. Scale
fillers require relatively long period to fill a pouch. As a
result, slower cycle continuous motion or intermittent motion is
required to provide additional fill time. In addition, larger
volume fills require more time, and therefore intermittent motion
through the filler may be necessary. More free flowing products,
such as sugar, may be dispensed using a diving funnel suitable for
filling continuously advancing pouches.
[0004] In light of the above, packaging machines have been
developed specifically for either intermittent or continuous
operation. In intermittent motion machines, the web is
intermittently advanced between dwell periods, and operations are
performed on the web during the dwells. In a continuous web motion
machine, on the other hand, the web continually moves at a set rate
and each station for performing operations is phased with the web
to perform the operation as the web passes through the station.
[0005] Most conventional packaging machines do not accurately form
pouches out of weak or unsupported web materials. Conventional
machines typically use a single pair of drive rolls to pull the web
through the machine. As a result, weaker web materials stretch as
they are pulled through the machine, thereby causing the pouch
forming apparatus to be misaligned with the web. In addition, the
web material must be sufficiently strong to withstand the force
necessary to pull the web through the machine without breaking.
These conventional packaging machines are therefore overly limited
in the types of web material which may be run.
[0006] The problem of web stretch is exacerbated in conventional
packaging machines using an intermittently advancing web. In
intermittent operation, the web is repeatedly pulled and released
as the web is advanced incrementally through the machine. The
repeated pulls place a significant amount of strain on the web
which tends to tear, break, or overly stretch weaker web
materials.
[0007] A related problem with many conventional packaging machines
is the need for an excessive amount of area in which to store a
festoon of web material. Machines using intermittently advancing
webs typically have a roll of web material which continually
advances to reduce the stretch problems noted above. The
continually advancing roll, however, requires storage space for
excess web material during the dwells between incremental advances.
Most machines having an intermittently advancing web therefore
provide for a festoon area in which a buffer length of web material
is stored. The conventional festoon sections typically employ a
dancer roll which moves to accommodate the varying downstream web
demand. The festoon sections are typically designed to store 4-5
repeat lengths of web material, thereby unduly extending the amount
of floor space required for the machine.
[0008] Most conventional packaging machines further use a
mechanical line shaft to drive the pouch forming components of the
machine. As a result, extensive machining and retooling is often
required to modify such machines to form different pouches.
Furthermore, most or all of the machine is provided as an integral
unit, with pouch forming operations running off of the mechanical
drive line. As a result, individual components or groups of
specific components may not be individually operated and
tested.
SUMMARY OF THE INVENTION
[0009] A general aim of the present invention is to provide a
packaging machine capable of running unsupported web material.
[0010] A related object of the present invention is to provide a
packaging machine which minimizes the area required for a festoon
section.
[0011] Another object of the present invention is to provide a
packaging machine comprising modules which, when combined, provide
a complete packaging machine.
[0012] A related object of the present invention as to provide
separate pouch processing modules that may be independently
operated and tested.
[0013] In light of the above, the present invention provides a
packaging machine having improved web tension control. In addition
to the driver rolls, the present invention incorporates a second
pair of infeed rolls to pull the web through an infeed section of
the machine. As a result, tension load on the web is divided into
sections. The infeed and drive rolls are located on opposite sides
of a sealing station. The speed of the infeed and drive rolls is
controlled to produce a predetermined positive draw rate through
the seal station, thereby controlling web tension therethrough.
[0014] In addition, the present invention reduces tension through
the infeed section. The pouch material is provided as a wound roll
that is unwound to dispense the web. A power driven reel unwinds
the roll to thereby reduce tension in the web. A festoon is located
between the reel and infeed rolls to supply a buffer of web
material. The festoon has at least one translating roll which moves
to accumulate or play out web material as needed. In the preferred
embodiment, a sensor measures the location of the translating roll
and delivers a location signal. A controller for controlling speed
of the reel is responsive to the location signal to adjust the reel
speed according to translating roll position. As a result, the
translating roll indicates downstream demand which allows the reel
motor to adjust accordingly, thereby relieving potential tension
spikes through the web.
[0015] The variable speed motor on the unwind reel further
minimizes the area required for the festoon. It will be appreciated
that, in either continuous or intermittent modes, the web is
advanced at an average speed through the sealing section. The reel
motor is controlled to supply web at an average velocity matching
that of the sealing section, thereby reducing the amount of festoon
needed in the infeed section. The amount of festoon section
required is further reduced by using the buffer sensor noted above
so that the reel speed is further adjusted according to actual
downstream demand. In intermittently advancing machines, it will be
appreciated that the web roll is relatively heavy and therefore has
too much inertia to stop and start the reel for each incremental
advance. Accordingly, the reel speed follows a cycle in which the
speed increases and decreases for each incremental web advance.
[0016] The present invention further provides a modular pouch
forming machine. Each module is capable of interfacing with
previous or subsequent sections as needed, and internal
registration-related operations are performed independently. For
example, a supply module has a pair or motor driven infeed rolls
for supplying a folded web at a desired speed. A sealing module has
a pair of drive rolls adapted to pull the web from the outlet of
the supply module. The drive rolls are motor driven and controlled
to thereby adjust the speed of the drive rolls. Downstream of the
drive rolls is a cutter for separating individual pouches from the
web. Finally, a filling module receives the individual pouches and
carries them through a pouch filler. The pouches are carried in
clamps, and a transfer device transports the pouches from the
cutter to the clamps. Variable speed motors are drivingly connected
to the transfer device in clamps to thereby adjust speed. When
supplied together in a line, a controller coordinates the speeds of
the motors in each of the modules so that the web and pouches are
advanced at a constant rate. When supplied individually, the
modules incorporate the appropriate drives for operating the motors
which may be coupled to an outside controller for individual
operation and testing.
[0017] These and other aims, objectives, and features of the
invention will become more apparent from the following detailed
description when taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a schematic view in perspective of a packaging
machine in accordance with the present invention.
[0019] FIG. 2 is an enlarged perspective view of a pouch filler
section for use with the packaging machine of FIG. 1.
[0020] FIG. 3 is a block diagram of the controls of the packaging
machine of FIGS. 1 and 2.
[0021] FIGS. 4A-F are schematic top views of a seal station
performing a box motion.
[0022] FIGS. 5A and B are schematic side views of the unwind,
accumulator, and related controls.
[0023] FIGS. 6A and B are enlarged top and side views of the
currently preferred seal section.
[0024] While the invention is susceptible of various modifications
and alternative constructions, certain illustrative embodiments
thereof have been shown in the drawings and will be described below
in detail. It should be understood, however, that there is no
intention to limit the invention to the specific forms disclosed,
but on the contrary, the intention is to cover all modifications,
alternative constructions and equivalents falling within the spirit
and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] Referring now to the drawings, a packaging machine 10 is
illustrated in FIG. 1. The packaging machine 10 produces pouches 12
from a continuous web 14 of material. The web 14 has pre-printed
registration marks 62 at spaced intervals corresponding to the
desired pouch width. The position of the registration marks with
respect to the printed artwork is known on the web. The web is made
of sealable material, which includes heat-sealable material (such
as polyethylene or polypropylene) and pressure-sensitive cold seal
film. The embodiments described below are directed mainly to a
machine 10 running heat-sealable web material.
[0026] According to the embodiment illustrated in FIG. 1, the
packaging machine has an infeed section 4 which supplies the folded
web 14 to a sealing section 6. The planar web material is typically
provided as a wound roll 16. The infeed section 4 has a reel 18 for
supporting the roll 16. The reel 18 rotates to unwind the roll 16,
thereby dispensing the web 14. The reel 18 may be conventionally
controlled or, as described in greater detail below, may have a
dedicated unwind motor 20 for varying an unwind speed. The web 14
is threaded over tension rollers 22 and a plow assembly 24 for
folding the web to form side panels 26 joined at a common bottom
edge 28. As illustrated in FIG. 1, the bottom edge 28 is formed
with a V-shape. The plow assembly 24 may also include a gusset
blade (not shown) for forming a W-shaped bottom edge. The folded
web 10 is passed through a pair of infeed rolls 30 to cleanly
define the fold lines in the web. In accordance with certain
aspects of the present invention, the infeed rolls 30 may also pull
the web through the first portion of the packaging machine, as
described in greater detail below.
[0027] The web 14 next travels through a sealing portion of the
machine 10 in which any of a number of pouch forming operations
take place. In accordance with the embodiment illustrated in FIG.
1, the web 14 first passes through a bottom or first seal station
32 for forming a bottom seal 34, such as a delta seal, in the web
14. The web 14 next passes through a side seal station 38 which
forms side seals 40 in the web. Upon leaving the side seal station
38, the web 14 is formed as a strip of pouches interconnected at
the side seals 40. The seal stations 32, 38 may use heated seal
bars to form seals in heat-sealable web material, or may use
unheated seal bars when the web material is a cold seal film. If
heated, the seal bars have a heating element such as a heat tube
extending therethrough. The heat tube is preferably electrically
operated and controlled to provide a desired sealing temperature at
the surface of the seal bar.
[0028] The seal stations 32, 38 are operable to form seals in the
web 14 as the web advances. In the currently preferred embodiment
illustrated in FIGS. 6A and B, the bottom seal station, for
example, has a pair of opposing bottom seal bars 36. A sub-support
37 is attached to the rear of each bottom seal bar 36, and each
sub-support 37, in turn, is attached to a carriage 56. Each
carriage 56 is adapted, such as by bearing sets, to slide along
upper and lower tracks 250, 251 which extend along the length of
the sealing section, as best shown in FIG. 6B. The sliding
carriages 56 allow the bottom seal bars to translate back and forth
parallel to the web path, defined herein as longitudinal
motion.
[0029] The bottom seal bars 36 are further operable in a direction
perpendicular to the web path, defined herein as lateral motion.
The tracks 250, 251 are attached to end supports slidably mounted
on rails 256, 257 extending perpendicular to the web path (FIG.
6B). As a result, the upper and lower tracks 250, 251 are operable
in the lateral direction to reciprocate the bottom seal bars 36
into and out of engagement with the web path.
[0030] The side seal station 38 has a structure similar to that of
the bottom seal station 32. As best shown in FIG. 6A, the side seal
station comprises two pairs of opposing side bars 42. Sub-supports
43 are attached to the seal bars 42. The sub-supports 43, in turn,
are attached to carriages 58 mounted for translation along the
upper and lower tracks 250, 251. As a result, the side seal bars 42
are also operable in both longitudinal and lateral directions.
[0031] The combination of the laterally moving sub-supports 37 and
the longitudinally translating carriages 56 allows the seal bars to
be driven in a box motion. As best shown in FIG. 4A, the bottom
seal bars 36 begin in an initial position, in which the bars are
retracted from the web and the carriages 56 are at an upstream
position. From the initial position, the carriages 56 are driven
downstream at a same speed as the web, as shown in FIG. 4B. With
the carriages 56 still moving downstream, the sub-supports 37 are
driven laterally inwardly so that the seal bars 36 engage the web
14 (FIG. 4C). The bottom seal bars 36 are held in the inward
position for a period of time sufficient to form a bottom seal as
the carriages 56 continues to advance with the web 14 (FIG. 4D).
After the bottom seal 34 is formed, the seal bars 36 are retracted
and the carriages 56 reverse direction so that the web 14 advances
downstream relative to the seal bars 36 (FIG. 4E). With the bottom
seal bars 36 retracted, the carriages 56 moves longitudinally
upstream toward the initial position (FIG. 4F). The bottom seal
station 32 then repeats the above-described box motion to form
subsequent bottom seals 34. The side seal station 38 is operated in
a similar fashion.
[0032] In the above embodiment, the sealing stations 32, 38 operate
in a duplex mode, in which the web 14 advances two web widths
between each actuation of the seal bars. Accordingly, the bottom
seal bars 36 are two pouch widths wide to simultaneously form two
bottom seals 34. Similarly, the side seal station 38 carries two
pairs of side seal bars 42. The machine 10 may also be operated in
a simplex mode, whereby the web 14 is advanced a single pouch width
between each actuation. In simplex mode, the bottom seal bars 36
are only one pouch width wide, and the side seal station 38 has a
single pair of side seal bars 42.
[0033] In the preferred embodiment, variable speed motors are used
to operate the bottom and side seal stations 32, 38 in the box
motion. With respect to the bottom seal station 32, a variable
speed motor 57 is coupled to each carriage 56 for driving the
carriages longitudinally (FIGS. 6A and B). The motor 57 is
preferably a linear motor having a magnetic rod 261 extending along
the length of the sealing section 6. A motor housing 262 is mounted
on the carriage 56 and operates back and forth along the rod 261.
As a result, movement of the housing 262 along the rod 261 directly
drives the attached carriage 56 longitudinally along the upper and
lower tracks 250, 251. Motors 59 also drive the side seal carriages
58. The motors are preferably linear motors having housings 267
mounted on the same magnetic rods 261.
[0034] The lateral motion of the bottom and side seal bars 36, 42
is also preferably motor driven. A variable speed motor 33 is
mechanically linked to the tracks 250, 251 to laterally reciprocate
the tracks, thereby driving the seal bars 36, 42 into and out of
engagement with the web 14 (FIG. 6B).
[0035] While the embodiment illustrated in FIGS. 6A and B is
currently preferred, it will be appreciated that other arrangements
may be used in accordance with the present invention, as long as
the seal bars 36 are operable to translate in the longitudinal and
lateral directions. For example, as schematically illustrated in
FIG. 1, a single carriage mounted under the web may support seal
bars on both sides of the web. In such an embodiment, however, a
second motor must be supplied for each carriage to drive the
lateral motion of the seal bars.
[0036] The seal bars are operated to engage the web as the web
advances for both continuous and intermittent web motion. It will
be appreciated that for intermittent web motion, the machine 10 of
the present invention could be operated so that the seal bars
engage the web during dwells, as is conventional. In the currently
preferred embodiment, however, the seal bars always contact the web
as the web advances, regardless of whether the web is advancing
continuously or intermittently. By operating the seal stations in
this manner, the seal bars will always be in contact with the web
for a sufficient period of time to form the seals regardless of the
dwell time between each intermittent advance of the web.
Furthermore, the machine operates in a similar fashion for both
continuous and intermittent web motion, thereby simplifying the
controls and providing a machine which operates in a consistent
manner.
[0037] According to the embodiment illustrated in FIG. 6A, the
sealing section further comprises a cooling station 272. The
cooling station 272 has cooling bars 273 carried by sub-supports
274. Carriages 275 carry the sub-supports 274 and are mounted on
the upper and lower tracks 250, 251. Accordingly, the cooling
station 272 is operated in the box motion similar to the bottom and
side seal bars 36, 42. The cooling bars, however, are kept at a
cool temperature in contrast to the heated seal bars. The cooling
bars 273 set the side seals in the web so that the side seals 40
are stronger and do not stretch as the web 14 is pulled through the
machine 10. The sealing section may further include additional
mechanisms for notching, punching, and emboss coding the web. These
additional components are located downstream of the cooling
station.
[0038] A pair of drive rolls 44 are located downstream of the seal
stations to pull the web through the sealing section of the machine
10 (FIG. 1). The drive rolls 44 are positioned to pinch the web 14,
thereby frictionally advancing the web. In accordance with certain
aspects of the present invention, the drive rolls are operable both
continuously and intermittently. In the preferred embodiment, a
variable speed motor, such as drive roll servomotor 45, is coupled
to and operates the drive rolls (FIG. 3).
[0039] A cutter is positioned immediately downstream of the drive
rolls 44 (FIG. 1). According to the present invention, the cutter
is adapted to cut the web at the formed side seals as the web
advances. In the currently preferred embodiment, the cutter
comprises a pair of cutter rolls 46, a first roll having a
plurality of circumferentially spaced blades 48 and a second roll
having a plurality of similarly spaced cutting surfaces 50. The
cutter rolls 46 are mounted for rotation so that a blade 48
contacts the web 14 at the same time as an associated cutting
surface 50 to thereby sever a leading pouch 12 from the web. In the
preferred embodiment, a variable speed motor 64 operates the cutter
rolls 46 (FIG. 3). Each pouch severed by the cutter rolls 46 is
then transferred to a pouch filling section 8 by a transfer
mechanism 54, as described in greater detail below.
[0040] In the preferred embodiment, the above-described sealing and
cutting mechanisms are operated with an adjustable dwell period
between subsequent operations. A system controller 15 is programmed
to adjust the dwell of the components to thereby adapt the machine
10 for different operating parameters. In the preferred embodiment,
the machine 10 uses electronic line shafting to synchronize the
motor-driven components. An oscillator generates a pulse stream and
is connected to a microprocessor in the system controller 15. The
pulse stream corresponds to the web speed such that a given web
speed has a corresponding pulse rate. The pulse rate is adjusted
proportionally to web speed. As a result, the distance the web
advances between pulses is always constant, and components may be
placed at locations downstream of a fixed point on the machine
which correspond to certain pulse counts. Web speed is defined
herein as the instantaneous rate of travel of the web 14 as it
advances. Under this definition, web dwell time during intermittent
motion is not used to compute the instantaneous web speed.
[0041] According to the illustrated embodiment, the machine 10 has
an infeed sensor 68 located at a registration point for sensing the
registration marks 62 and generating a sync signal as each
registration mark passes. The sync signals inform the system that
the web is positioned in the machine 10 with a registration mark 62
at the registration point. With a defined registration point,
therefore, components may be positioned at known distances
downstream of that point and controlled to actuate a determined
number of pulses after the registration signal. For example, the
first seal station 32 may be positioned 2 feet downstream of the
registration point, which may correspond to 1,000 pulses. The
system controller 15 may then control the seal station to actuate
after 1,000 pulses are counted from the sync signal. The pulse rate
is generated such that, for this example, 1,000 pulses correspond
to 2 feet of web travel for any web speed.
[0042] As noted above, a sync signal indicates that a registration
mark 62 is passing the sensor 68. The registration marks 62 are
longitudinally spaced at pouch width intervals along the web 14 so
that consecutive sync signals indicate that the web has advanced
one pouch width, defined herein as a cycle. In the most preferred
embodiment, therefore, the web-engaging components are positioned
downstream of the infeed at pouch width intervals. As a result, the
components are controlled to operate with reference to each sync
signal.
[0043] The pulse stream allows the machine 10 to be quickly and
easily adapted to form pouches of various sizes. As noted above,
the components of the machine may be positioned at pouch width
intervals. If the pouch width is changed, the position of the
components must also be adjusted for the new web width. Using the
example presented above, the first seal station 32 may be
repositioned 1 foot downstream of the registration point rather
than 2 feet. The microprocessor of the system controller 15 may be
programmed so that, for the new position, the first seal station 32
is actuated after 500 pulses are counted from the sync signal
thereby adjusting the dwell period of the first seal station. The
servomotors 57, 59 of the carriages 56, 58 allow the first and
second seal stations 32, 38 to be quickly and easily repositioned
for the new pouch width. Furthermore, the system controls are
programmed to modify the dwell periods between component
operations. Accordingly, the pouch making machine 10 of the present
invention is quickly and easily adapted for various pouch
sizes.
[0044] The above-described box motion of the seal stations 32, 38
is also preferably timed using the pulse stream. Accordingly, the
carriages 56 of the bottom seal station 32 are controllably
positioned a known distance downstream of the infeed sensor 68. As
diagrammatically illustrated in FIG. 3, the system controller 15
controls drives 219, 220 to generate a drive signal to the carriage
motors 57 to move the carriages 56 downstream at a speed equal to
the web speed after a predetermined pulse count. As the carriages
56 move, the system controller 15 signals the reciprocating motor
33 through drive 221 to actuate the bottom seal bars 36 laterally
inward after a predetermined number of pulses have elapsed after
each sync signal. The motor 33 holds the bottom seal bars 36 in the
inward position for another predetermined number of pulses
corresponding to a sufficient period of time to form a seal in the
web. Once the seal is formed, the bottom seal bars are retracted
and the carriages 56 are driven upstream to the initial position.
The same procedure is followed after each sync signal. The side
seal station is operated in the same fashion. While the use of a
pulse stream is preferred, it will be appreciated that other types
of controls may be used to actuate the seal stations, such as the
use of optical sensors which provide a feedback signal to initiate
actuation of the components.
[0045] In the preferred embodiment, the drive roll servomotor 45 is
also controlled by the system controller 15 using the pulse stream.
The user selects a desired web speed and a pulse rate corresponding
to that web speed is generated. The system controller 15 delivers a
drive signal through drive 214 to the drive roll motor 45 to
operate the drive rolls at the appropriate speed (FIG. 3).
[0046] In the preferred embodiment, the seal stations 32, 38 are
provided with automatic registration to the web 14. To accomplish
registration, a sensor is coupled to the carriage motors of each
seal station. The sensor senses the registration marks 62 and
delivers a seal registration signal. The bottom seal station 32,
for example, carries a bottom seal sensor 60, as shown in FIGS. 1
and 3. The controller 15 receives the signal and drives the
carriage motors 57 to position the carriages 56 relative to the
registration mark 62 so that the bottom seal bars 36 are positioned
over appropriate seal points on the web. As a result, the bottom
seal station 32 is continually and automatically registered with
the web 14. Any carriage position adjustments required for
registration are compensated for by the microprocessor in the
system controller 15, so that the box motion is executed in
registration with the web 14. The side seal station 38 has a side
seal sensor 63 for effecting similar registration. As shown in FIG.
3, the carriage motors 59 have drives 216, 218 coupled to the
system controller 15. The sensor 63 delivers a location signal to
the controller 15 which, in turn, adjusts the drive signals sent to
the motors 59.
[0047] In the preferred embodiment, the cutter rolls 46 are also
independently controlled to register with the web 14. A cutter
sensor 66 is mounted a fixed distance upstream of the cutter rolls
46 for sensing the registration marks 62 and delivering a cut
signal. The system controller 15 signals a drive 224 in response to
the cut signal to control the speed of the cutter motor 64 so that
the cutting rolls 46 cut through each side seal 40 (FIG. 3).
Because the distance between the cutter sensor 66 and the cutter
rolls 46 is known, the cutter servomotor 64 may be programmed to
dwell for a given number of pulses upon receiving the cut signal
before actuating the cutter rolls 46.
[0048] In a preferred embodiment, the infeed rolls 30 are
controlled to provide a registered web to the sealing section. The
infeed rolls 30 are driven by an infeed servomotor 70. The infeed
sensor 68 is located immediately upstream of the infeed rolls 30
and senses the registration marks 62, as noted above. The system
controller 15 compares the sync signals from the infeed sensor 68
with the desired web speed and adjusts a drive signal provided by
drive 208 to the infeed servomotor 70 (FIG. 3). In intermittent
mode, the infeed servomotor 70 is controlled so that the web 14 is
advanced past the infeed rolls 30 by a predetermined distance. In
continuous mode, the infeed rolls 30 are controlled so that the
actual web speed, as measured by the infeed registration signals,
matches the desired web speed. In either mode, operation of the
infeed rolls is adjusted so that a registered web is supplied to
the sealing section.
[0049] The infeed rolls 30 provide a second point at which the web
14 is pulled through the machine 10. The infeed rolls 30 engage the
web 14 at a point upstream of the sealing section 6 to pull the web
through the infeed section. As a result, the amount of web stretch
through the sealing section is minimized, thereby improving the
accuracy of the machine.
[0050] The infeed rolls 30 and drive rolls 44 are controlled to
maintain a desired web tension level through the sealing section 6.
An infeed servomotor 70 is drivingly connected to the infeed rolls
30. The controller 15 controls the drive roll and infeed servo
motors 45, 70 to maintain a predetermined positive draw rate
through the seal station. The positive draw may be established by
either inputting a drive roll speed and setting the infeed roll
speed relatively slower or by inputting the infeed roll speed and
driving the drive rolls at a relatively faster speed. In either
event, a controlled tension level is established through the
sealing section 6. The only stretch load on the web 14 is that
created by the positive draw and therefore the tension level may be
controlled to run relatively weak web materials.
[0051] In accordance with certain aspects of the present invention,
the unwind reel 18 is power-driven to reduce tension spikes in the
web 14. The reel motor 20 has a drive 212 coupled to the system
controller 15. As a result, the controller adjusts reel motor speed
according to downstream demand. For example, in intermittent mode,
the web 14 is advanced through the seal section 6 at an average
speed in between pauses. The reel 18 is controlled to operate at an
average speed which matches that of the seal section 6. The roll 16
is relatively heavy, and therefore has too much inertia to stop and
start the roll in accordance with the web. The system controller 15
therefore drives the reel motor 20 in a controlled cycle in which
the reel motor speed is increased and decreased for each
intermittent increment of web travel. In continuous mode, the reel
motor 20 is driven at a more consistent speed. In either mode, the
reel motor 20 unwinds the roll 16 to thereby reduce tension in the
web.
[0052] Speed of the unwind reel 18 is further adjusted through the
use of an accumulator 76. As best shown in FIGS. 5A and B, the
t-shaped accumulator 76 is located in the infeed section 4
comprising translating rolls 74, 75. The accumulator 76 is fixed to
pivot about a point 78. Fixed rolls 73 are also positioned near the
accumulator 76. When the web 14 is threaded over the rolls, it will
be appreciated that the accumulator 76 stores a buffer length of
web material. A device for providing a known force, such as an air
cylinder 80 is connected to a bottom arm 82 of the accumulator 76.
Accordingly, it will be appreciated that as the accumulator 76
rotates counter-clockwise as illustrated in FIG. 5A, side roll 74
translates downward while side roll 75 translates upward, and
bottom arm 82 moves to retract the air cylinder 80. Clockwise
rotation of the accumulator 76, as shown in FIG. 5B, causes the
side arm 74 to translate upward and the side arm 75 to translate
downward, while the bottom arm 82 extends the air cylinder 80.
[0053] When the web 14 is entrained around the fixed and
translating rolls as shown in FIGS. 5A and B, the direction of
rotation of the accumulator 76 corresponds to downstream web
demand. In FIG. 5A, downstream web demand has decreased causing the
accumulator 76 to rotate counter-clockwise. The side rolls 74, 75
translate to accumulate slack web length in the buffer. In
addition, the air cylinder 70 is retracted. A sensor 77 measures
the position of the air cylinder 80 (and therefore the position of
the side rolls 74, 75) and delivers a position signal to the
controller 15. In response to the signal, the controller 15
decreases speed of the reel motor 20.
[0054] FIG. 5B illustrates the opposite situation, wherein
downstream web demand has increased, thereby causing the
accumulator 76 to rotate clockwise. Side rolls 74, 75 translate to
play out spare web length from the buffer to meet the increased
demand. The air cylinder 80 extends and the sensor 77 provides a
position signal to a controller 79. In response, the controller 79
increases speed of the reel motor 20 to meet the increased demand.
The buffer length of web material thereby accommodates variations
in downstream web demand. Furthermore, the position of the
accumulator is used to indicate downstream web demand, thereby
allowing reel motor speed to be adjusted accordingly. As a result,
tension spikes are minimized through the infeed section.
[0055] In accordance with additional aspects of the present
invention, the above-described unwind reel control minimizes the
amount of festoon area needed in the infeed section 4. As noted
above, the reel motor 20 is controlled to adjust speed according to
downstream demand. As a result, the amount of spare web material
needed to be stored in a festoon is minimized. The reduced festoon,
in turn, reduces the amount of floor space needed for the
machine.
[0056] The machine 10 further incorporates a pouch filling section
for filling and sealing the formed pouches. At the outlet of the
sealing section, the transfer mechanism 54 carries severed pouches
from the cutter rolls 46 to leading and trailing clamps 102, 104 of
the filler section. The clamps are carried on first and second
endless carriers, illustrated in FIG. 2 as first and second chain
sets 106, 108. It will be appreciated that other types of endless
carriers, such as timing belts or metal bands, may also be used in
accordance with the present invention. Furthermore, each endless
carriers may comprise a single member, or a set of multiple
members, FIG. 2 illustrating the latter by showing first and second
chain sets 106, 108 comprising a pair of chains. The clamps are
carried along a path which leads through a pouch filler 110. Once
filled, the top edges of the pouches pass through radiant heater
bars 112 which soften the pouch material. The pouches 12 with
softened upper edges are then fed through a pair of upper seal
rolls 114 to form an upper seal. The pouches then pass through a
pair of cool rolls 116 to set the upper seal, after which each
pouch 12 is picked off and transported from the filler section.
[0057] In the preferred embodiment, a variable speed motor 118
operates the transfer mechanism 54 to transfer each severed pouch
12 from the cutter rolls 46 to the clamps 102, 104 (FIG. 3). The
transfer motor 118 has an associated drive 236 for providing a
variable drive signal and is coupled to the system controller 15.
It will be appreciated that, because of spacing between the clamps,
the clamps are operated at a clamp speed greater than the web
speed. The transfer mechanism 54, accordingly, is driven at a
transfer speed which is slightly greater than the clamp speed. When
first gripping a pouch, the transfer mechanism slides against the
surface of the pouch until the pouch is severed from the web.
Similarly, the transfer mechanism slides against the pouch until
the pouch is carried away.
[0058] In the preferred embodiment, the transfer mechanism 54
provides a registration buffer between the sealing and pouch
filling sections. The transfer speed of the transfer mechanism 54
may be independently controlled so that the components of the
sealing section need not operate in registration with the clamps
102, 104 of the pouch filling section. As a result, the sealing and
pouch filling section may be independently registered with the web
and pouches, respectively. Registration between the components of
the sealing and pouch filling sections is not required, and
therefore the entire machine 10 may be brought into registration
with the web 14 more quickly and with minimal wasted web
material.
[0059] In the preferred embodiment, leading and trailing variable
speed motors 120, 122 operate the leading and trailing chain sets
106, 108. A drive 232 provides a variable signal to the leading
motor 120 and is coupled to the system controller 15 (FIG. 3). The
trailing motor is similarly controlled. The leading and trailing
motors 120, 122 operate the leading and trailing chain sets 106,
108 with a phase distance between the two so that the leading and
trailing clamps 102, 104 are separated by about a pouch width. The
leading and trailing chain servos 120, 122 allow the phase distance
to be adjusted to accommodate different size pouches. It will be
appreciated that whatever the phase distance, the chains are
operated at the same speed so that bags held in the clamp are not
stretched or crushed.
[0060] In the embodiment illustrated in FIG. 2, the trailing clamp
104 is moveable to allow the top of the pouch to be opened and
closed. The trailing clamp 104 comprises supports 126 which are
connected to the trailing chain set 108, preferably comprising a
pair of chains. A pair of support arms 128 are attached to the
supports. A clamp holder 130 is slideably mounted on the support
arms 128 for movement between closed and open pouch positions. In
the closed pouch position, as best shown by the left-hand pouch
illustrated in FIG. 2, the clamp holder 130 is positioned near the
upstream extent of the support arms 128. The clamp holder 130 is
slidable on the support arms 128 to an open pouch position as best
shown by the trailing clamp 104 located below the pouch filter 110
in FIG. 2. In the open pouch position, the clamp holder 130 is
positioned midway along the support arms 128 so that the clamp
holder 130 is relatively closer to the trailing clamp 104. It will
be appreciated that in a pouch 12 held by clamps in the open
position, the side walls of the pouch 12 expand outwardly away from
one another to allow access to the interior of the pouch.
[0061] In operation, the clamps 102, 104 are in the closed position
as the pouches 12 are transferred from the sealing section. Before
the pouch reaches the pouch filler 110, the clamp holder 130 is
moved to the open position to facilitate filling of the pouch. The
clamp holder 130 remains in the open position as the clamps pass
through the pouch filler and the pouches are filled with product.
After exiting the pouch filler 110, the clamp holder 130 is
repositioned back toward the closed position to allow the top edge
to be sealed.
[0062] The clamp holder 130 is repositioned using servo-controlled
upstream and downstream mechanisms. As best shown in FIG. 2, the
upstream pouch-opening mechanism comprises an advance arm 132
positioned before the pouch filler 110. The advance arm 132 has an
initial position in which the arm is located outside of the web
path. As the clamp holder 130 passes, the advance arm 132 rotates
to engage a rear face of the clamp holder and slide it toward the
open pouch position. The advance arm 132 completes a full
revolution to return to the initial position. If the upstream
mechanism has dual arms, the arms complete a half revolution. The
advance arm 132 is driven by a motor 136 phased with the system
controller 15 so that the advance arm rotates during each
cycle.
[0063] The downstream pouch closing mechanism preferably comprises
a retard arm 134 controlled similar to the advance arm 132. The
retard arm 134 extends into the path of the passing clamp holder
130 to impede further advancement of the clamp holder 130. Once the
clamp holder 130 reaches the closed position, the retard arm 134 is
rotated out of the path to allow the clamp holder 130 to pass. The
retard arm 134 executes a full revolution to return to the initial
position to await the next clamp holder 130. Rotation of the retard
arm 134 is controlled by a retard servomotor 140 The retard
servomotor 140 is controlled by the system controller 15 so that
operation of the retard arm 134 is phased with the system.
Accordingly, the retard servomotor 140 is actuated so that it
dwells for a portion of each cycle before rotating. During the
dwell, the retard arm 134 engages and pushes the clamp holder 130
toward the open pouch position. The downstream mechanism may have
two arms spaced by 180 degrees. for such an embodiment, the arms
rotate one-half revolution during each cycle.
[0064] As noted above, the filled and closed pouches 12 are then
passed between radiant heater bars 112 and top seal rolls 114 to
seal the upper edge of the pouches. The pouches may further pass
through cool rolls 116 to set the upper seal before being
discharged. The top seal rolls 114 and cool rolls 116 are driven by
variable speed motors connected to the system controller 15.
[0065] It will be appreciated that the above-described pouch making
apparatus may be provided as separate modules. As best shown in
FIG. 3, the machine comprises a supply module 200 for folding the
web and supplying it to downstream apparatus. In the illustrated
embodiment, the supply module 200 comprises the plow 24 and the
infeed rolls 30. The infeed rolls 30 are coupled to the variable
speed motor 70 which receives a drive signal from a drive 208. The
drive 208 is coupled to the system controller 15. The infeed rolls
30 pull the web 14 of planar material over the plow 24 to thereby
fold the material into mating first and second sides. The
controller 15 controls the speed of the infeed rolls 30 to thereby
provide a controlled web speed at an outlet of the supply module
200. In a preferred embodiment, a speed sensor is provided for
monitoring speed of the infeed rolls 30 to thereby allow the system
controller 15 to adjust the speed as necessary.
[0066] In addition, the supply module 200 preferably includes the
infeed sensor 68. The infeed sensor 68 is coupled to the system
controller 15 and senses the registration marks 62 on the web. The
infeed sensor 68 allows the controller 15 to feed web material
through the infeed rolls 30 to a predetermined point downstream of
the infeed rolls. The infeed sensor 68 also may be used to
determine actual speed of the web by measuring the amount of time
elapsing between registration signals. As a result, the infeed
sensor 68 may be used by the system controller 15 to further adjust
speed of the infeed roll motor 206.
[0067] In a most preferred embodiment, the supply module 200
includes the reel 18 for unwinding the roll of material. The
variable speed motor 20 is connected to the reel and receives a
drive signal from drive 212. The drive is coupled to the system
controller 15 so that reel motor speed may be adjusted. The supply
module 200 may further incorporate the accumulator 76 and
associated buffer strength feedback, as described in greater detail
above, to further adjust speed of the reel motor 210.
[0068] Upon exiting the supply module 200, the web next passes
through a sealing module 202. As illustrated in FIG. 3, the sealing
module 202 incorporates a pair of drive rolls 44 for pulling the
web 14 from the outlet of the supply module 200. Drive 214 drives
the motor 45 coupled to the drive rolls 44. The drive 214 is
further coupled to the system controller 15. Upstream of the drive
rolls 44 are the bottom and side seal stations 32, 38. As noted
above, the seal stations are adjustable in the longitudinal
direction and carry seal bars to form seals between the first and
second sides of the web at spaced locations. The sealing module may
include additional seal or other stations, as described above. For
sake of clarity, however, FIG. 3 illustrates only the bottom and
side seal stations. A cutter 46 is located downstream of the drive
rolls 44 for cutting the seals formed by the seal station 38,
thereby separating pouches from the web. The sealing module 202
therefore pulls the web from the upstream supply module 200, forms
seals therein, and separates formed pouches from the web for
downstream pouch operations.
[0069] In the preferred embodiment, the bottom and side seal
stations 32, 38 comprise moveable carriages 56, 58 which provide
for longitudinal movement along the web. The carriages 56 of the
bottom seal station 32 have variable speed motors 57 connected
thereto. Drives 219, 220 are connected to the system controller 15
and drive the motors 57 at the desired speed. The sensor 60 senses
the registration marks 62 on the web 14 and delivers a position
signal to the controller 15. The controller adjusts position of the
carriages 56 according to the position signal to thereby register
the seal bars with the web The side seal station 38 similarly has
the variable speed motors 59 connected to the carriages 58 having
associated drives 216, 218 coupled to the system controller 15. The
sensor 63 senses the registration marks 62 and delivers a location
signal to the controller 15. The controller 15 adjusts positions of
the carriages 58 according to the location signal to thereby
register the seal bars with the web.
[0070] In the illustrated embodiment, the seal bars of the bottom
and side seal stations 32, 38 are actuated by a single
reciprocating motor 33. The motor 33 has a drive 221 coupled to the
system controller 15. As a result, the controller 15 controls
reciprocation of the seal bars. It will be appreciated, however,
that the seal stations 32, 38 may have separate reciprocating
motors in accordance with the present invention.
[0071] In the preferred embodiment, the cutter 46 comprises a pair
of cutter rolls having the variable speed motor 64 connected
thereto. The motor 64 has a drive 224 coupled to the system
controller 15 for controlling operation of the cutter 46. The
cutter sensor 66 is positioned upstream of the cutter rolls for
sensing the registration marks 62 on the web 14. The controller 15
is responsive to signals sent by the sensor 68 to thereby trigger
the cutter rolls to cut the web. It will be appreciated, therefore,
that the registration-related sealing and cutting operations are
performed with independent registration and therefore do not rely
upon timing with web speed.
[0072] Pouches formed in the sealing module 202 are transferred to
a filling module 204 for filling, sealing, and removal for
distribution. The filling module 204 has at least the leading
endless carrier 106 carrying a plurality of clamp pairs. The
leading carrier motor 120 is connected to the endless carrier 106
and has the associated drive 232. The drive 232 is coupled to the
system controller 15 for adjusting the speed of the endless carrier
106. The filling module 204 further includes a transfer device 54
for transferring the pouches from the cutter 46 to the clamp pairs.
The transfer motor 118 is drivingly connected to the transfer
device 54 and has an associated drive 236 connected to the system
controller 15 (FIG. 3). The clamps are repositioned to open the
pouch for filling and close the pouch for sealing after filling, as
described in greater detail above and as illustrated in FIG. 2.
According to the illustrated embodiment, a mechanism located
upstream of the pouch filler opens the pouches while a separate
mechanism located downstream of the filler closes the pouches. The
pouches are then carried through a mechanism for forming a top
seal, such as the radiant heater bars 112 illustrated in FIG. 2.
The upper seal roller 114 then forms the seal and a pair of cool
rolls 116 set the seal. The controller 15 adjusts the speed of the
transfer device 54 and endless carrier 226 so that the pouches are
transferred from the cutter to the clamps.
[0073] In the preferred embodiment, the filling module 204
comprises speed sensors on the endless carrier and transfer
mechanism to thereby provide feedback for adjusting the actual
speed of those devices. In addition, as noted above, the transfer
device 54 preferably comprises a vacuum belt. It will further be
appreciated that the pairs of clamps may be mounted on separate
endless carriers to thereby adapt the clamps for pouches of various
sizes, as described in greater detail above.
[0074] The present invention not only provides modules which may be
used in a line to provide a complete pouch forming machine, but
also modules which may be individually operated and tested. With
regard to the supply module 200, speed of the infeed rolls 30 is
controlled, preferably using the infeed sensor 68, to provide a
registered web of material to the downstream apparatus. The supply
module 200 provides the drive 208 for operating the motor 206, so
that an outside controller may be used to run the module. The web
14 supplied at an output of the supply module 200 may be inspected
to verify that the rolls are operating at the proper speed and
advancing the proper distance.
[0075] The sealing module 202 may similarly be independently
operated. The web 14 may be fed through the drive rolls 44 and the
formed pouches may be collected at the output of the module. As the
web is pulled through the sealing module 202, the seal stations and
cutter independently register with the web to form the pouches. The
module 202 includes the drive roll, cutter, and carriage drives
214, 224, 216, 218, 220, and 221 to allow a separate controller to
operate the module. Furthermore, the sealing module 202 preferably
includes the sensors 60, 63 which are adapted for connection to the
separate controller to properly control the carriages 56, 58.
[0076] The filling module 204 may similarly be tested
independently. The transfer device 54 and endless carriers 106, 108
are driven so that pouches fed into the transfer device are carried
to the clamps. The filling module 204 provides the endless carrier
and transfer device drives 232, 233, 236 which allow a separate
controller to adjust their respective speeds. As a result, the
present invention provides a truly modular apparatus in which the
separate modules may be individually operated or combined to
provide a complete pouch forming apparatus. In the preferred
embodiment, the filling module 204 further includes speed sensors
on the carrier and transfer device motors 120, 122, 118 to provide
feedback information to the separate controller.
[0077] In light of the above, it will be appreciated that the
present invention provides a new and improved packaging machine for
forming pouches from a web of material. Web tension is controlled
throughout the machine to allow weak web materials to be run. More
specifically, the machine uses a pair of infeed rolls to pull the
web through an infeed section while the drive rolls pull the web
through the sealing section. The speed of the infeed and drive
rolls is controlled to maintain a positive draw rate through the
sealing section. The infeed section further has an unwind reel
having a variable speed motor connected thereto. The unwind reel
motor responds to downstream web demand to thereby minimize tension
spikes through the infeed section. The power driven unwind reel
further minimizes the amount of festoon needed in the infeed
section. The present invention further provides a packaging machine
having modular sections. Registration-related operations through
each module are independently controlled so that the modules need
only interface to coordinate input and/or output speeds. As a
result, the modules may be separately operated for testing or other
purposes, or combined to provide a complete pouch forming
machine.
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