Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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WINDER FOR BAG MACHINE
FIELD OF THE INVENTION
The present invention relates generally to the art of bag making. More
specifically, it relates to making and winding bags.
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BACKGROUND OF THE INVENTION
There are a variety of known bag machines used for making bags from a
continuous
film, such as a polyolefin film. Commercially available bag machines, winders,
and folders include
CMDS Models 3113, 1100 series, 1500, 4013R0 series, and other machines.
Examples of patented
prior art bag machines include US Patents 6117058, 4934993, 5518559, 5587032
and 4642084 and
US Patent Publication 20060084559.
Generally, those machines unwind the film from a roll. The film may be a
single
film, or folded film, or a (flat) tube. Bags are formed by placing seals on
the film in desired
locations. The seals may form the bottom/top and/or sides of the bag.
Perforations may be included
denoting sides or top/bottom of adjacent bags. Other operations may be
performed such as
separating and/or folding.
The bag machine shown in USP 6117058 is owned by the owner of this invention,
and may be seen in Figure 1. Prior art rotary bag machine 100 continuously
processes a web or film
201 using a dancer assembly 203, a pair of drum-in rolls 205 and 206 (203-206
are part of an input
section), a sealing drum 208, a pair of drum-out rolls 210 and 211, a sealing
blanket 213, a pair of
knife-in rolls 215 and 216, a knife 218 (which could be any other web
processing device such as a
perforator, knife, die cutter, punching station, or folding station), a pair
of knife-out rolls 219 and
220 (210-220 are part of an output section), and a controller 221. Input
section or unwind section, as
used herein, includes the portion of a bag machine where the web is received,
such as an unwind and
a dancer assembly. Output section, as used herein, includes assemblies that
act on a web
downstream of the seals being formed, such as perforators, winders, folders,
etc.
The web is provided through dancer assembly 203 to a forming drum 208. Drum
208 includes a plurality of seal bars 209. The seals bars are heated and
create the seals forming the
bags from web 201. Web 201 is held against drum 208 (and the seals bars) by a
Teflon coated
blanket. End to end bags are formed with one seal from the drum, and side to
side bags are formed
with a pair of seals. The drum diameter may be adjusted and/or less than all
of the seal bars turned
on to determine the distance between seals, and hence bag size.
Generally, rotary motion machines register a downstream rotary knife to
perforate between two seals, or beside a seal. The prior art of Figure 1
provides that after web
201 leaves drum 208 it is directed to rotary knife 218, which creates a
perforation between
bags, or could separate adjoining bags. When the bags are end to end bags, the
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perforation is placed close to the single seal such that when the bags are
separated, the
perforation and the perforated end is the top of one bag, and the seal is the
bottom of the
adjoining bag.
Controller 221 is connected to the various components to control speed,
position, etc. Sensors may be used to sense print on the web to form the seals
and/or
register the perforation (place it in the correct location with respect) to
the seal. Also,
sensors may detect seals to try and create the perforation in the correct
location.
Many bag machines include a winder after the knife. Examples of prior
art winders include US Patents 4,667,890; 4,695,005; 6186436; and 5899403.
Prior art
winders either have a rotating turret with multiple spindles or a single fixed
spindle and
web stopper. A desired number of bags is wound about the spindle, forming the
roll.
The roll is then pushed off, often using a push off palm. The roll may be
paper banded,
and unacceptable rolls may be culled. The prior art describes various ways to
properly
direct the leading end of the roll to the desired spindle, and to control the
winding.
Multiple spindle prior art winders require rotating a turret to move the
spindle to the starting and winding position. This adds complexity to the
machine, and
makes air connections difficult. Also, because the turret rotates, it is used
with a push off
palm that scrapes the spindle over only part of its circumference. Moreover,
moving
turrets, push off palms, and air horns can interfere with one another or
crash. Stationary
winders are limited in the speed because of the time it takes to remove a
roll. Prior art
winders typically cannot used pneumatic devices in applications over 30 cpm.
Rather,
such a winder capable of 40 cpm would require servo controlled devices.
Accordingly, a winder with stationary spindles that operates at higher
speeds than prior art single spindle systems is desirable. Preferably such a
winder can be
used with pneumatic devices, and can receive air connections easily.
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SUMMARY OF THE PRESENT INVENTION
According to a first aspect of the present invention, there is provided a
winder for a bag machine or sheet machine comprising:
a) an infeed nip defined between a first and a second infeed rollers, wherein
a
film path approaches the first infeed roller, follows a surface of the first
infeed roller to the infeed nip for an arc of at least 10 degrees, and then
the
film path is toward at least one winding station, and the film path includes
a first spindle film path;
b) at least one film guide is disposed along the film path for at least the
arc to
the infeed nip, and further along the film path downstream of the infeed
nip, wherein the at least one film guide is recessed in the first infeed
roller
at least along the arc; and
a first spindle, located along the first spindle film path
According to another aspect of the present invention, there is provided a
winder for a bag machine comprising; an infeed nip defined between two infeed
rollers; a
first spindle, located along a first alternative film path, wherein after
leaving the infeed
nip the film can follow the first alternative film path nip to the first
spindle to be wound
about the first spindle; and a second spindle, located along a second
alternative film path,
wherein after leaving the infeed nip the film can follow the second
alternative film path
nip to the second spindle to be wound about the second spindle.
According to a first aspect of the invention a winder for a bag machine
comprises an infeed nip and two spindles. Each spindle is located along one of
two
alternative film paths.
According to a second aspect of the invention a method of winding bags
from a continuous film includes feeding the film into a winder and alternately
directing
the film along a alternative paths to one of two spindles. The alternations
occur after a
plurality of bags, such as a roll, are wound.
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According to a third aspect of the invention a bag machines includes an
unwind section, a forming section, and a winder. The winder includes an infeed
nip and
two spindles, each located along a respective alternative film path.
The spindles are fixed position spindles in one alternative embodiment.
The alternative film paths are predominantly downward in other
embodiments.
An over speed nip may be provided between the infeed nip and the
alternative film paths.
The over speed nip operates in an intermittent mode and in an every bag
mode, and/or has a user adjustable over speed, in various embodiments
The winder includes an overlapper between the infeed nip and the
alternative film paths, in other embodiments. The overlapper can include a
plurality of
rods moved in an orbit that intersects the film path in at least two
locations. The orbit can
be generally elliptical.
The overlapper includes a plurality of air nozzles in other embodiments.
The over speed nip has air nozzles disposed to direct the film to one
alternative film path, and other air nozzles disposed to direct the film to
the other
alternative film path.
The winder includes conveyor belts along the alternative film paths in
other alternatives. The conveyor belts can pivot at an end closest the infeed
nip.
The winder includes static pinners along the alternative film paths, that
can be bipolar, in various embodiments.
The winder includes pop-up fingers disposed along the alternative film
paths in other alternatives.
The winder includes paper banders near the spindles in various
embodiments.
The winder is driven with pneumatic air in one embodiment.
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The winder includes push off devices that scrape the spindles over
substantially 360 degrees in other alternatives.
According to a fourth aspect of the invention a winder for a bag or sheet
machine includes an infeed nip, a film guide or guides and spindle or
spindles. The film
approaches the infeed nip by following the surface of an infeed roller for an
arc of at least
degrees. The film path is then through the nip and toward the spindle. The
film guide
is disposed along the film path for at least the arc on which the film wraps
the infeed roll,
and further along the film path downstream of the infeed nip. The film guide
is recessed
in the infeed roller at least along the arc.
10 According to a fifth aspect of the invention a method of
winding bags
from a continuous film includes guiding the film with a first infeed roller
and at least one
film guide recessed in the first infeed roller, along the surface of the first
infeed roller for
an arc of at least 10 degrees. Then guiding the film with the film guide and
roller to an
infeed nip. Then guiding the film to at least one winding station and winding
the bags.
The film guide is stationary and touches the film along the arc according
to one embodiment.
The film guide is further recessed below the surface of the roll at the
infeed nip according to another embodiment.
The arc is at least 45, 60 and 90 degrees in various embodiments.
The winder includes a second spindle, and each spindle is on an alternative
film path in another embodiment.
A rotatable brush is disposed at a location where the film path can follow
either the alternative film path to direct the film to a selected path in
another embodiment.
An over speed nip is located on the film path downstream of the infeed nip
and upstream of the brush and/or a source of air blows to the film from one
side and/or
the other side and diverts film from the film path to take up excess film for
overlapping
adjacent bags in other embodiments. The sources of air are located upstream of
the
rotatable brush and downstream of the over speed nip in another embodiment
A finger/guide is disposed near the spindle or spindles to remove rejected
bags in another embodiment.
There are three film guides extending across the film in another
embodiment.
A second film guide is disposed on the opposite side of the film in another
embodiment.
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According to a sixth aspect of the invention a bander for a bag machine
includes a conveyor for providing tape to a spindle and two sources of air.
The tape
approaches the spindle from a first direction and passes above the spindle,
and wraps
around a roll of bags wound about the spindle. One source of air is directed
to support
the tape as the tape approaches the spindle. 'The other source of air is
directed to force the
tape around the roll of bags as the tape passes over above the spindle, aiding
the tape
wrapping about the roll. The one source of air also supports the tape as it
wraps about the
roll of bags, thereby aiding the tape wrapping about the roll.
The first source of air is mounted on an air horn disposed to be moved to
and away from the spindle in an alternative embodiment.
Other principal features and advantages of the invention will become
apparent to those skilled in the art upon review of the following drawings,
the detailed
description and the appended claims.
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BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is diagram of a prior art bag machine;
Figure 2 is diagram of a winder in accordance with the present invention;
Figure 3 is diagram of a winder in accordance with the present invention;
Figure 4 is diagram of a bander winder in accordance with the present
invention; and
Figure 5 is diagram of an infeed roller in accordance with the present
invention.
Before explaining at least one embodiment of the invention in detail it is to
be understood that the invention is not limited in its application to the
details of
construction and the arrangement of the components set forth in the following
description
or illustrated in the drawings. The invention is capable of other embodiments
or of being
practiced or carried out in various ways. Also, it is to be understood that
the phraseology
and terminology employed herein is for the purpose of description and should
not be
regarded as limiting. Like reference numerals are used to indicate like
components.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the present invention will be illustrated with reference to a
particular bag machine, method and winder, it should be understood at the
outset that the
invention can also be implemented with other machines, methods, and winders,
including
draw tape machines, rotary overlap machines, intermittent machines, sheet
machines and
other known machines.
Generally, the present invention is described with respect to a winder that
can be used with, or is part of, a prior art bag machine to make a roll of
bags for easy
packaging, transporting, dispensing, and use. The preferred embodiment is
described
with respect to a bag machine such as that shown in US Patent 6117058, or
available
commercially as the CMD 1270 bag machine, or a modular bag machine. The
invention is contemplated as a winder, a winder and separator, a winder,
separator and
overlapper, or an entire bag machine. Overlapper, as used herein, includes a
device or
section that overlaps succeeding bags. The bag machine prior to the winder is
described
below, since it can be the prior art machine described above. Other bag
machines may be
used as well.
The winder receives the foinied bags as a film, and can separate them
using an over speed nip. Over speed nip, as used herein, includes a nip
wherein at least
one driven roller has a circumferential speed greater than the speed of the
film prior to the
nip. The nip can operate in an every bag mode, or in an intermittent mode to
separate
bags only at the start/end of rolls. Every bag mode, as used herein, includes
operating for
every bag within a roll. Intermittent mode, as used herein, includes not
operating for
every bag within a roll, such as operating only at the beginning or end of a
roll, or for a
few bags within a roll. The bags can be overlapped in the every bag mode.
After separating, a film divertor directs the film to one of two spindles.
Each winding spindle takes turns winding film, which eliminates bottlenecks
and allows
for higher speeds, higher cycle speeds, and lower count rolls. The film is
directed by the
divertor along one of two alternative film paths to one of the two spindles or
winding
stations. Film path, as used herein, is the path film takes through the bag
machine or
winder, excepting any area where film is accumulated for winding. Alternative
film path,
as used herein, includes a path followed by the film or bags a portion of the
time the
winder is in use.
The alternative paths are preferably predominantly downward, allowing
rejected film or missed transfer film to be rejected to the floor in a
convenient location.
Predominantly downward, as used herein, includes more vertical (with gravity)
than
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horizontal, The spindles are fixed position spindles. Fixed position spindles,
as used
herein, includes spindles that do not move from a location, such as in an
orbit, but can
rotate.
When the spindle in use is wound with a complete roll, the leading edge of
the first bag of the next roll is directed along the other alternative path to
the other
spindle. Thus, the winder can wind immediately on the other spindle without
moving the
spindles, and without having to remove a roll before winding the next roll.
Various embodiments use one or more of the following features, which
can be used alone, or in many combinations. Air can be used to direct the film
as desired,
and pop-up fingers and/or an air horn can be used to start the roll. Static
pinning can be
used to hold the bags to the spindle, and bipolar static pinning can be used
to hold the tail
of the last bag of a roll to the roll. Conveyors can be used to guide the film
along the
alternative paths, and the conveyor can pivot as the roll gets larger, to
accommodate its
growing diameter. A paper bander can be used and the drying time for the glue
can be
accommodated since the glue can dry while the other spindle is being used. A
push off
device can be used to remove rolls, and can scrape substantially 360 degrees
around the
circumference of the spindle since the spindles are fixed position spindles.
Substantially
360 degrees, as used herein, includes over the entire circumference except for
occasional
small interruptions.
Turning now to Figure 2, a diagram of a winder 200 in accordance with
the preferred embodiment is shown. Winder 200 may be downstream along the film
path
of bag machine 100 of Figure 1. Many of the alternatives mentioned above are
shown,
although as stated above, all need not be included.
Film 201 travels from perforator or knife 218 (Figure 1) to an infeed nip
defined between rolls 203 and 205 (Figure 2), at least one of which is driven.
The infeed
nip draws or feeds the film into winder 200. (Infeed nip can refer to the
infeed for a
machine or a section. Here it is used to refer too the infeed of the winder
section.)
The preferred embodiment provides for a vertical feed of the web through
the infeed nip. This allows the machine to be uni-handed with respect to an
operator side,
and can accommodate both left and right hand floor plans.
Film 201, after leaving the infeed nip, is provided to an over speed nip
defined between rolls 307 and 309, at least one of which is driven. (Film 201
is provided
to other stations directly, or indirectly after leaving the infeed nip in
various
embodiments). Preferably the over speed is servo driven and the over speed
percent can
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be changed easily by the user for a wide perforation repeat distance, such as
from 10" to
250" without changing parts.
In an intermittent mode it can run perforation-connected film and separate
one of plurality of bags from its succeeding bag by running over speed only
after a certain
count is complete. In an every bag mode it can be an overlapper and separate
and overlap
each bag by running over speed all the time. (Every bag made includes not
separating a
few bags in each roll). The over speed nip can aid in diverting the web to the
appropriate
alternative path by not running over speed during the last bag of the
overlapped roll.
Perforation detection is not required (but can be provided) when separating
bags.
An overlapper includes rods 311-315 mounted to move in a generally
elliptical orbit that intersect the path of film 201 in two places (above and
below the nip,
preferably). Generally elliptical, as used herein, includes a non circular,
non angular path.
The orbit is shown clockwise in Figure 2, where the roll is being wound on a
spindle 337,
located along one of the alternative film paths. The rotor reverses direction
and moves
the rods in a counter-clockwise direction when a spindle 338 (located along
the other
alternative film path) is being used. The rods pull the film laterally, and
can aid in
separating, although the over speed nip alone can be used to separate if the
overlapper is
not installed. The rods temporarily accumulate the film to allow for
overlapping
succeeding bags. Overlapped regions are shown as 317 and 318, and 319 and 320.
The rods are preferably 0.5" diameter steel rods supported on each end
with a chain or timing belt, including a driven sprocket and a tensioner
sprocket,
preferably servo driven. This reduces the distance the web must jump where it
is not
supported. An air curtain or series of air nozzles may be used to help the
film jump the
gap created by the mechanical overlap rods. Alternatives includes using air
for
overlapping, using fewer or more rods, using a different orbit, or other known
overlappers.
Over speed rollers 307 and 309 preferably include 0.25"wide grooves on a
1" repeat across the face of both roller faces, to provide clearance for a
plurality of air
nozzles 322-325 in each groove. Air nozzles 222-225 are used to direct the
film to the
desired spindle. The upper air nozzles 322 and 323 are used to divert the web
to the
opposite roller and the lower air nozzles 324 and 325 are used to divert the
web down to a
nearby conveyor belt 327 or 328, disposed along the film path. As shown in
Figure 3, air
nozzles 322 and 325 are off, and air nozzles 323 and 324 are on, directing
film 201
toward spindle 317. Nozzles 322 and 325 are on, and nozzles 323 and 324 off,
when the
film is being directed toward spindle 318.
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When a roll is completed, and the nozzles had been directing the trailing
edge of the roll to one spindle, the nozzles are then controlled to direct the
leading edge
of the next roll of bags to the other spindle. Thus, the nozzles alternately
direct the film
to one of two paths. The change in paths, or alternations, occur after a
plurality of bags --
a roll -- are wound. If the separator is in an intermittent mode, then nozzles
perform an
alternation after separating. In the every bag (overlap) mode they perform an
alternation
after a given count.
The preferred embodiment provides that the right and left spindles and
associated components are mirror images of one another, although this is not
required.
Thus, spindle 338 winds counter-clockwise and spindle 337 winds clockwise.
The web, as it travels to spindles 337 and 338, is preferably held against
conveyor belts 327 and 328 with a series of round elastic ropes. Also, one
embodiment
provides for static pinners 330 and 331 to hold the film against conveyor
belts 227 and
228. Static pinners 330 and 331 can be bi-polar static pinners to not only
hold the film
against the conveyor, but to also cause the tail of the last bag of a roll to
cling to the roll,
by turning off the static neutralizer for the last few bags. Thus, the
invention provides for
statically pinning a tail of a last bag in a roll to the roll, to aid in
manual handling of rolls,
in automation handling of roll, and reduce the need to glue the tail of the
last bag.
Conveyor belts 227 and 228 are preferably one wide belt or a series of
narrower belts with a 1" gap there between. The gap allows for pop-up finger
340, 341
(one or more in various alternatives) to help direct the leading edge of the
first bag into an
air horn 342, 343, and around the winding spindle. Pop up fingers 340 and 341
intermittently direct the film near the spindle and retract after the first
bag is transferred.
The gap between belts also allows hot melt tail gluing to be used with less
chance of glue
getting on a conveyor belt.
Conveyor belt 328 is preferably mounted such that it pivots at an end
closest to the infeed nip, and away from fixed position spindle 338, as shown
by the
dashed lines and arrow 345, as the film roll grows in diameter. A like pivot
is used for
conveyor 327.
Each winding station may have a paper bander 346, 347. Because one
bander can be used while the opposite spindle is winding, two banders which
each run
20cpm allow the overall winder to cycle at 40cpm. Also, because there are two
winding
stations, each cycling at 20 cpm, pneumatic devices may be used with an
overall speed of
40cpm.
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The spindles preferably use a prior art CMDO-designed Teflon sleeve or
bead blasted/chromed design. Also, because the spindles are fixed position
spindles, they
can use a simple push-off device that does not need to pivot, and can scrape
at
substantially 360 degrees around the spindle circumference to remove film
easier with
less chance of binding. The fixed position also allows for simple air
connections to the
spindles.
Because there are two stations cycling at 20 cpm (counts per minute), the
machine runs at 40 cpm, and more time is allowed for roll inspection, culling,
and
rejecting than is allowed by a single station 40cpm machine.
An alternative embodiment of a winder 300 is shown in Figure 3 and can
include many of the features described above, including two winding stations.
The
various embodiments may be combined as desired, choosing features from each or
the
prior art that suit the needs of a particular application.
Winder 300 includes an infeed nip defined between a pair of infeed rollers
403 and 405, a controllably over speed nip defined between a pair of rollers
407 and 409
for separating adjacent bags, and spindles 437 and 438. Generally, winder 300
operates
consistent with winder 200, except as described below.
Film or web 201 approaches the infeed nip by wrapping or following along
a portion of the surface of roller 403 before reaching the nip. The film rides
on an arc
equal to or more than 10, 45, 60, or 90 degrees in various embodiments.
A plurality of stationary film guides 412, mounted on support 410, are
recessed in roller 403. Preferably, the surface of guides 412 is flush with
the surface of
roller 403 such that the web rides on the film guides, ropes (not shown), and
the surface
of roller 403. Recessed in a roller, as used herein, includes residing
partially or
completely in recessed areas on a roller. The recesses may be grooves or
channels, and
have a depth in the preferred alternative embodiment such that the web rides
on both the
film guides and the surface of roller 403. Guides 412 are preferably comprised
of metal
with a slippery coating and fit closely within the recesses of roller 403,
such as clearance
on the sides of no more 0.010 inches. This allows the film to lie flat without
getting
caught in spaces between the recesses and guides 412.
Referring to Figure 5, one embodiment of roller 403 is shown with
recesses 501 for film guides 412 and recesses 502 for ropes. This embodiment
provides
for nine guides and two ropes. Also, a plurality of air relief holes 505
(counterbored, 1/2"
inch diameter by 1/8" deep) are provided to help the film lie flush on the
surface of roller
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403 (and on film guides 412, not shown on Figure 5). There are corresponding
holes on
the opposite side (180 degrees away from holes 501) on roller 403.
A film follows the surface of a roller when it rests generally on the outer
surface, and does not require the film to conform to the recesses etc. Film
guide, as used
herein, includes a structure used to support and guide the film, and does not
require
driving the film. Surface of a roller, as used herein, the surface of a roller
that is
substantially the same distance from the axis of the roller.
Film guides 412 may be co-extensive with the arc of roller 403 on which
the film rides prior to the nip, or it may be more or less extensive.
Preferably, film guides
412 and the arc are of sufficient extent to support or touch film 201 as it
approaches the
infeed nip. The inventors have found that the stationary film guides, along
with
approaching the nip from the side so the film 201 passes over guides 412,
ropes (not
shown) and roller 403 allow for faster and more stable operation.
Film guides 412 extend through the infeed nip, but are recessed just below
(1/16 inches, e.g) the surface of roller 403 closest to the film path at the
nip, so as to
allow the infeed nip to properly pinch film 201. Surface of a roller closest
to the film
path, as used herein, is the surface of a roller that the film generally
follows. Below a
surface of a roller, as used herein refers to closer to the axis of roller
than the surface of
the roll that makes contact with film.
A plurality of film guides 460 are connected to film guides 412, and
mounted on a block 464. Film guides 412 and 460 may be considered continuous
film
guides. A plurality of guides 462 are mounted on a block 466 and guide film
201 from
the reverse side of film 201. Film guides 460 and 462 are preferably spaced
sufficient to
allow the film to pass easily, such as a total of 1/16 inch therebetween.
Guides 460 and
462 are recessed in rollers 403, 405, 407 and 409, and at the infeed and over
speed nips
are recessed below the surface to avoid interfering with the nip (for example
1/32 inch
each). Film guides 412, 460 and 462 may be one or several individual guides.
Ropes that wrap rolls 403 and 407 (and in one embodiment 405 and 409)
are also used to move the film. Ropes are particularly helpful in driving thin
films, such
as 6 micron high density polyethylene, but are omitted for some applications,
particularly
for heavier films.
The preferred embodiment uses ropes toward the center of the film, and
guides toward the edges for more support. For example, with a six inch web an
arrangement of 3 film guides 412 (two of which are near the edges of film 201,
and one in
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the center), and two ropes, each between the -film guides, is used. More film
guides are
used for wider films (and/or more ropes may be used as needed).
Winder 300 may be operated in a continuous mode or an overlap mode. In
the overlap mode film 201 is separated into adjacent bags by over speed
rollers 407 and
409. Rollers 407 and 409 may be intermittently brought together or
intermittently sped
up to separate film 201 into bags. (Other methods of separating adjacent bags
may be
used as well). Figure 3 shows a bag 201a which has been separated from film
201.
When in a continuous mode rollers 407 and 409 may be run at film speed, left
separated,
or be idler rolls.
Guides 460 and 462 extend past the nip where bags are separated, to help
film 201 jump the gap below rollers 407 and 409.
Overlapping requires downstream the film move more slowly, and that
excess film be taken up during the overlapping. The embodiment above (Figure
2) shows
one way to separate film and take of film for overlapping. Figure 3 shows
another way of
taking up excess film for overlapping. Down stream rollers 411 and 413 move
the film
slower than rollers 403 and 405 in overlap mode (they run at the same speed as
rollers
403 and 405 in non-overlap mode).
Air sources or air nozzles/pipes 404a and 406a (mounted on supports 404
and 406) divert the film from its path to take up excess film as the
overlapping occurs.
As shown on Figure 3, nozzle 404a is active, and diverts the film from the
film path and
to the left, thus taking up the excess film. Diverted from the film path, as
used herein,
refers to accumulating bag or film when the bag or film follows a path other
than the film
path. Nozzle 404a directs air at least partially in a cross direction, and
toward the right
side of the film on Figure 3. Nozzle 406a also directs air at least partially
in a cross
direction, but to the opposite (left) side of the film. Nozzles 404a and 406a
may each be
implemented with multiple nozzles, a single nozzle, and/or an air pipe.
Bag 201a then moves to a winding infeed nip between rollers 411 and 413,
which are under sped to account for overlapping. The preferred embodiment
calls for
under speeding them by 20%. Ropes 411a and 413a are provided around rollers
411 and
413 to help move and guide the film to one or more downstream conveyors
427/428.
One embodiment provides for a single winding station. However, the
alternative preferred embodiment of Figure 3 provides for two windings
stations, each
having a spindle 437/438, conveyor 427/428 wrapped about a roller 468.
After leaving rollers 411 and 413, bag 201a may be directed to the desired
winding station a rotating brush 416. Brush 416 is preferably a full width
brush
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positioned to touch ropes 411a/413a and/or belts 427/428, and at a location
where the
film path can follow either a first alternative spindle film path to spindle
437 or a second
alternative spindle film path to spindle 438. Figure 3 shows overlapped bags
201a and
202b going to winding station 437, thus brush 416 is rotating clockwise. The
preferred
embodiment provides for rolls to be alternately wound on spindles 437 and 438.
After being properly directed by brush 416 bags 201a and 201b are guided
past an optional barrel pinner 422, an optional hot glue applicator 424, and
an optional
bander 426 (i.e., a station or device to apply a band about a roll of wound
bags). A pair of
airhoms 442/433 are used to facilitate starting a roll. A pair of sorting
trays 450/451
direct wound rolls into a bin, or to the floor, depending if they are accepted
or rejected. A
pair of fingers/strippers 440 and 441 are disposed near spindles 437/438 to
help remove
rejected bags and/or rejected rolls.
One embodiment of bander 426 is shown in Figure 4 and includes a
conveyor 610 wrapped around a roller 612, a film guard 619, a source of air
616, and a
source of air 608 mounted on air horn 343, which cooperate with the conveyor
428 to
wrap a tape 601 about a wound roll of bags 618 on spindle 438 (Figure 3).
Bander 426 is
shown for the left bander on Figure 3, and the tight bander will be a mirror
image.
As tape 601 is moved by conveyor 610 to roll 618, tape 601 passes over
the top of roll 618. Nozzles 608 direct air to tape 601 and help support the
tape (i.e., keep
it from falling before it reaches roll 618. Guard 615 helps prevent tape 601
from
wrapping around conveyor 610 and roll 612
After tape 601 reaches roll 618, nozzle 616 directs air to force tape 601
downward, around the right side of roll 618, thereby aiding tape 601 wrapping
about roll
618. As tape 601 is wound about roll 618 air from nozzles 608 support the tape
as it
wraps about the bottom of roll 618, thereby aiding tape 601 wrapping about
roll 618.
Nozzles 608 and 616 may each be single nozzles, an air pipe, or each a
plurality of nozzles. Also, nozzles 608 may be mounted on any support, and
need not be
on airhorn 433. Nozzles 616 may also be mounted on any support.
Numerous modifications may be made to the present invention which still
fall within the intended scope hereof. Thus, it should be apparent that there
has been
provided in accordance with the present invention a method and apparatus for
making and
winding bags that fully satisfies the objectives and advantages set forth
above. Although
the invention has been described in conjunction with specific embodiments
thereof, it is
evident that many alternatives, modifications and variations will be apparent
to those
skilled in the art. Accordingly, it is intended to embrace all such
alternatives,
CA 02727368 2015-05-19
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modifications and variations that fall within the scope of the appended
claims.
