Note: Descriptions are shown in the official language in which they were submitted.
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LABELING APPARATUS AND METHODS THEREOF
Field of the Invention
The invention is generally related to labeling machinery, and in particular to
adhesive
application, web registration and article handling therewith.
Background of the Invention
In a great number of consumer product markets, particularly those which are
low-margin
and/or price-driven, an ongoing need exists for various manners of reducing
product costs. For
example, just-in-time manufacturing techniques, which reduce costs through
minimizing inventory,
have grown in prominence. In addition, improved packaging techniques and
materials are constantly
being developed to minimize the packaging component of product costs.
Just-in-time manufacturing can place significant demands on product
manufacturing and
packaging equipment due to the quick turnaround that is often required to
timely fill customer orders.
As a result, there is an ongoing need for a manner of increasing the speed of
product manufacturing and
packaging equipment so that inventory costs can be reduced without adversely
impacting a
manufacturer's ability to fill customer orders in a timely fashion.
For example, for bottled beverages such as soft drinks, beer, juice, liquor,
etc., significant
efforts have been expended in attempting to lower the costs associated with
applying product labels to
beverage containers such as glass bottles, plastic bottles, aluminum cans, and
the like. A particularly
cost-effective manner of labeling beverage containers utilizes a continuous
web of pre-printed polymer
label material that is cut into predetermined lengths; supplied with adhesive,
and applied directly to the
surface of a container. Adhesive costs may also be reduced by applying
adhesive only to the leading
and trailing edges of individual labels and wrapping the labels completely
around the containers.
Label machines have been developed that are capable of relatively high-speed
operation, e.g.,
as high as 750 containers/minute or more. However, such machines have been
found to be limited in
severalrespects.
One significant problem associated with such conventional labeling machines is
that it is
difficult to reliably control tension in a web of label material being
processed at high speed. Among
other concerns, a large roll of label material spun at high speed has a great
deal of momentum, which
often necessitates a dedicated tensioning mechanism between a supply of label
material and a cutting
mechanism. A tensioning mechanism, however, can introduce variable tensions at
different points
along the web, not to mention adding complexity and increasing the cost of the
machines. Moreover, in
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many conventional label machine designs, separate cutting and transfer (or
vacuum) drums are utilized,
with the web at least partially drawn to a downstream transfer drum prior to
severing a label from the
web with an upstream cutting drum - an arrangement that can introduce variable
tension to the web
before and after cutting.
As a result of these tensioning concerns, most conventional labeling machines
require that a
non-stretchable polymer film such as polypropylene or polystyrene be used as
the web material.
Stretchable polymer films such as polyethylene are often unsuitable for use
with such machines because
the varied tensions in the web can stretch such films lengthwise and introduce
unacceptable positioning
errors when cutting the web. Web material constructed from non-stretchable
polypropylene or
polystyrene, however, can be three or four times more expensive than a
stretchable material such as
polyethylene. As a result, many conventional labeling machines prohibit the
ability of a producer to
take advantage of the substantial savings that could otherwise be realized
through the use of less
expensive filins.
Therefore, a significant need exists in the art for an improved manner
controlling tension in a
web of material, particularly when supplying a web of label material in high
speed labeling machines
and the like. Moreover, a significant need exists for a manner of controlling
web tension such that less
expensive stretchable polymer filnis may be utilized in high speed labeling
applications.
The process of conveying articles such as containers past a label transport
drum introduces
another significant problem associated with conventional labeling machines, as
well as with other
machinery that utilizes multiple stations that require different transport
parameters at different stations.
For example, with regard to labeling machines, many conventional labeling
machine designs utilize
turrets or star wheels to convey individual articles past a label transfer
drum at a controlled rate and
with a controlled separation, or "pitch", between sequential articles so that
each article is initially
presented to the transfer drum at a position thereon where a leading edge of a
label is located. A turret
is typically a rotatable body that includes mechanisms disposed about the
periphery for gripping articles
from the top and bottom ends thereof. A star wheel is typically a rotatable
body that includes pockets
disposed around its periphery that contact the sides of articles to advance
the articles through the
machine. Articles moving past a transfer drum are typically rotated as they
pass the transfer drum (e.g.,
by virtue of contact between the drum and a fixed guide) so that labels an the
drum are wrapped around
the articles.
Turrets typically provide the greatest degree of precision in handling and
transporting articles.
However, due to the additional components and coordinated movements required
to bring top and/or
bottom gripping mechanisms into contact with articles, turrets are relatively
slow and expensive. Star
wheels are typically faster and less expensive, but have the drawback that
articles are not held as
securely and can become misaligned within the star wheels.
For example, star wheels are typically used in conjunction with a moving
conveyor that
supports the articles and moves at a fixed linear velocity. A label transfer
drum then rotates with its
outer surface traveling in the same direction as the conveyor. The velocities
of the pockets in the star
wheel and the outer surface of the drum are typically matched so that an
article contacts a label on the
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drum while each is traveling at the same velocity. The articles may also be
rolled or spun about its
longitudinal axis to wrap the label around the article - typically by passing
the article by a fixed guide
or contacting the article with a relatively faster-moving belt.
Given that the leading edges of successive labels are spaced apart from one
another along the
outer surface of the transfer drum, it is often necessary for articles to be
spaced apart with the proper
pitch to ensure proper alignment of articles and labels. 'This typically
requires that the star wheel and
transfer drum rotate in such a manner that the articles and labels travel
faster than the conveyor.
However, unless the linear velocities of the articles are identical to that of
the conveyor, the articles
may become tilted within the pockets of the star wheel due to friction as the
articles slide along the
surface of the conveyor. As a result, applied labels may have loose or bunched-
up portions due to the
misalignment of the articles relative to the labels.
Moreover, other than when the labels are actually applied, it is often
desirable to minimize the
rotation of articles while disposed upon the conveyors so that the articles
are conveyed in a more
controlled manner. Conventional star wheels, which operate at a constant
velocity, are often not
I S capable of adequately controlling the rate of rotation of articles, which
can result in label mis-
registration and/or article jams at high speed.
Some conventional designs also incorporate feed screws at the entry and/or
discharge ends of a
label application station to convey the articles in a linear direction. The
feed screws may also have
variable pitches to control the linear velocity of the articles, and thus the
separation between articles.
However, feed screws also are unable to accurately control the rotational
rates of articles, and thus,
label mis-registration and/or article jams still remain a significant concern.
Therefore, a significant need also exists for an improved manner of conveying
articles such as
containers past a transfer drum in high speed applications, in particular so
that the movement of such
articles is carefully controlled.
High speed operation of continuous-feed labeling machinery also requires
careful control over
labels as they are fed from the supply roll, cut from the web, supplied with
adhesive and applied to
containers. In most continuous-feed labeling machinery, labels are transferred
from station to station by
a sequence of rollers and drums. A variety of mechanisms, including web
tension, mechanical clamps
and forgers, and vacuum surfaces, are typically used to assist in the transfer
of labels (whether severed
or unsevered from a web) from station to station.
Pressurized air is also used in some labeling machinery to improve label
control. For example,
pressurized air directed toward the leading edge of a label may be used to
assist in directing the label
from a cutter drum to a transport drum after the label has been severed from a
web, or to assist in
directing the label from a transport drum to the surface of a container. Also,
in some applications
pressurized air may be supplied to an unsupported portion of the backside of a
seam formed between
the leading and trailing edges of a label wrapped around a nan-cylindrical
article, to strengthen the
bond between the leading and trailing edges.
One area of particular concern for many labeling applications is controlling
the feed of labels
during the application of adhesive. Adhesive applicators used are typically
utilized to deposit an
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adhesive material such as a hot melt or pressure sensitive glue composition to
a label immediately prior
to placing the label on a container. Typically, such applicators include an
adhesive roller that forms a
nip with a label transport mechanism such as a vacuum drum, and that is
supplied with a source of
adhesive on its outer periphery such that adhesive is applied to a label
supported on the transport
mechanism as the label is fed past the adhesive roller.
One difficulty associated with conventional adhesive applicators is that the
leading edge of a
label can in some instances separate from the surface of the transport
mechanism and follow the
adhesive roller as the leading edge of the label exits the nip formed by the
adhesive roller and the
underlying transport mechanism. When this occurs, the label will often jam the
adhesive applicator and
the remainder of the labeling machinery, resulting in defective product and
downtime associated with
cleaning and restarting the machine.
To address this concern, some adhesive applicators utilize mechanical devices
such as a series
of parallel wires adjacent an adhesive roller to keep the leading edge of a
label from wrapping around
the roller. However, in many instances the parallel wires leave undesirable
patterns on the adhesive
applied to each label. Further, glue droplets on the wires can contaminate
both the labels and the
transport mechanism. Misadjusted wires can also wrinkle or displace labels on
the transport
mechanism, resulting in defective labeled articles.
Other labeling machinery designs utilize mechanical hold down devices such as
clamps or
fingers on a transport mechanism to hold down the leading edge of each label
as the label passes an
adhesive applicator. Moreover, in some designs in which labels are transported
past an adhesive
applicator via a vacuum drum, a relatively high level of vacuum is used to
resist the adherence of labels
to the adhesive applicator. However, mechanical hold down devices and the like
are often
mechanically complex and can negatively impact performance and reliability.
Increased vacuum levels
can induce stretching of the label material and necessitate the use of larger
and more expensive vacuum
pumps.
Another difficulty associated with conventional adhesive applicators is the
overspray of
adhesive that often occurs during the application of adhesive to the trailing
edge of a label. In
particular, when a label passes through the nip between an applicator roller
and a transport mechanism,
the trailing edge (which is supported on the surface of the transport
mechanism) may be separated from
the roller by a gap across which excess adhesive may spray. A portion of the
adhesive may deposit on
the surface of the transport mechanism, resulting in contamination of the
mechanism. Unless the
overspray is periodically cleaned from transport mechanism, the transport
mechanism may jam and halt
the machine, requiring a more extensive and time consuming cleaning and
restart operation. Given that
any downtime negatively impacts the efficiency and productivity of labeling
machinery, cleaning
operations of any type are often highly undesirable.
Therefore, a substantial need exists in the art for an improved manner of
feeding labels
through labeling machinery, and in particular to improve the reliability of
the application of adhesive to
labels.
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I-~igh speed operation of continuous-feed labeling machinery also rGquircs
c~fi~l control over
the containers m which labels are applied. Considerable development efforts,
for example, have been
expended in improving the handling of concaincts, wh~hCr filled, or empty,
during a label application
operation. Containers are typically fed to and from a labeling machine via a
com~cyot. Infeed and
$ discharge mechanisms are typically used to cr3nsporr conraiaess from the
coa~eyor, past a Label transport
mechanism, and back onto the conveyor.
Significant development cffottR have been directed ep the iafeed mcchatzissn
at the head of a
labeling machine, incorporating feed screws, srarwheels, balls and the like to
remove conraittes5 from a
conveyor and pass the containers past the label transport mechanism with a
desired aroouat of separation.
Starwhrds, For example, are toothed whrels that entry containers around sn
arcnate gaide within the
gaps formed between adjactnt Math, also referred ro as pockets. Ia some
implementations, mntltiplc
starwheels are used, e.g., where a small flow statwhcel introduces initial
gaps between incoming
containers so that the containers can be picked up by a relatively larger
infted statwttcel for
ttsnsportatioa past a Eabel transport drum
1 S One potential probJem~tic cltatacteristic of a starwheel, however, is chat
is some instances gaps
can cast between a container, the starwheel and the guide around which the
container is transported Ar
high speed, the presence of gaps can introduce vibrations sad Jeopardize the
stability of the containers
fed through the labeling machine, poss~ly causing concaiacr tnisfeeds and
jamming of the machine.
In addition, at the discharge end of a labeling machine, coatpaxasively less
attcatioa has been
devoid to the stability of containers transported back onto a conveyor afar
being labeled. With many
labeling machines, far example, labels arc rolled onto a container by
sandwiching the container benrreen
a fixed actuate guide and a roratirtg label tt~ansport drum. once a label is
applied, one or more moving
belts located downstream of the drum contact the containers acd atttmpt to
cancel out the spinning of the
container before the container is returned to the wuveyor. Iiowcvcr, at higher
speeds, belts tray not
providt adequate stability, particularly with light-weight containers having
relatively high c~ers of
gravity {e.g., unfi'lled two Iittr plastic beverage conmittersi. Misfecds of
containers may occur, jartttsrittg
the machine and rcqniring a time consuming cleaning sad restart operation
Ther::forc, a significant need also continues to exist for an improved manner
of reliably
aartspotting containers through labeling taachinery, and is particular, ro
improvt the stability of
containers transported by infeed and discharge mechanisms of a labeling
maehiwe during high speed
operations.
US 5380381 generally discloses a labeling machine with a variable speed
cuttiztg head that
severs labels from a web prior to transporting the labris to a vacuum drum
DE 1255567 generally ~Iiscloscs a cutter dean with a radially-movable lozifc
used to seer
labels from a web prior to transporting the labels to a vacuum drum.
DE 4314142 grnerally discloses a device for folding wrappers around articles
using cooperating
pairs of arms driven by cam atrangsrnents.
DB 3529716 generally discloses a device for transporting articles where
slidable articles carriers
are tnovablc tadialty to discharge tIcfcctivc articles to an alternate
conveyor.
AMENDED SHEET ,
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GH 2181163 ge~tets~lly discloses a labeling apparaa~s with vacQUm ports and
blowoff parts on a
label drum.
DE-U 1961419 gcnerally discloses an arricic aansporr ~wah variable sped aims
for ~msportiag
ar~iclcs.
WO 97110953 Severally discloses a labeling machine with as inftcd starwheel
for transportixig
articlcs to a fabeliag station.
AMENDED SHEE~6
:.2 .
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Summary of the Invention
The invention addresses these and other problems associated with the prior art
by providing in
one aspect an apparatus and method that utilize a rotatable drum implementing
both an attraction
mechanism and a cutter mechanism to controllably sever segments of material
from a web. The drum is
rotated at a rate greater than the rate at which the web of material is
advanced so that the attraction
mechanism supplies the sole source of tension in the web. Moreover, the cutter
mechanism severs
segments of material while at least a portion of the web of material engages
the outer surface of the
drum. As such, the outer surface of the drum tends to slide relative to the
leading edge of the web, with
the attraction mechanism operating to apply a controlled pulling force
thereto. Among other
advantages, this permits less-expensive stretchable web material to be
utilized, thereby lowering
material costs. Moreover, greater reliability at high speeds is also often
realized - an important
consideration for many just-in-time manufacturing applications.
The invention also addresses additional problems associated with the prior art
by providing in
another aspect an apparatus and method that dynamically control the relative
rates of advancement of a
web of material and an outer surface of a drum such that a predetermined
length of material is advanced
forward of a predetermined rotational position of the drum so that the
predetermined length of material
is severed from the web of material while at least a portion of the web of
material engages the outer
surface of the drum. The rate of advancement of the outer surface of the drum
is different from that of
the web of material such that relative slippage of the web of material and the
outer surface of the drum
is provided. As such, a web of material may be controllably severed into
predetermined lengths using a
relatively mechanically-simple configuration, which aids in accuracy and
reliability, particularly in high
speed applications.
The invention further addresses additional problems associated with the prior
art by providing
in another aspect an apparatus and method that utilize a carrier mechanism
having at least one article
carrier pivotably coupled to a rotatable hub and controlled via a caroming
mechanism that varies the
angular velocity of the article carrier relative to that of the hub. The
article carrier is configured to
receive and transfer an article along an article engaging surface of a fixed
guide. The hub rotates about
a first axis, and the pivotal coupling between the article carrier and the hub
defines a second axis that is
substantially parallel to and separated from the first axis. The caroming
mechanism is operatively
coupled between the article carrier and the hub and configured to pivot the
article carrier about the
second axis in response to rotation of the hub about the first axis to thereby
vary the angular velocity of
the article carrier relative to that of the hub.
Through the use of the above configuration, the carrier mechanism may be
configured to
match predetermined transport parameters associated with each of first and
second stations that the
carrier mechanism transports articles between. In one embodiment, the
predetermined transport
parameters may be based upon the pitch between sequential articles processed
by each of the first and
second stations so that the pitch of the articles transported by the carrier
mechanism may be controlled
to match that expected by each of the stations. In another embodiment, the
predetermined transport
parameters may be based upon the velocity of each article processed by the
first and second stations so
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that the velocities of the articles transported by the carrier mechanism may
be controlled to match those
expected by each of the stations. As a result, greater control is provided
over transported articles to
permit high speed operation with greater reliability.
Consistent with another aspect of the invention, a fluid dispenser is used in
connection with an
adhesive applicator to improve the reliability of label feed by a label
transport mechanism during the
application of adhesive to a label. The fluid dispenser is configured to
direct a flow of fluid toward a
nip formed between an adhesive roller on the applicator and the label
transport mechanism, and from a
position upstream from the nip. Among other advantages that will become more
apparent below, doing
so reduces the likelihood that the label will undesirably follow the adhesive
roller upon the application
of adhesive to the label.
Consistent with another aspect of the invention, a starwheel is provided
including a rotatable
hub and an engagement surface defining a pocket configured to engage an
article. The engagement
surface is resiliently coupled to the rotatable hub to move between first and
second positions to vary a
rotational position of the pocket relative to the hub. Among other
applications, the starwheel may be
used to control the flow of articles to a second, infeed starwheel in a
labeling machine in such as
manner that the clearance between the articles and the infeed components is
minimized, thereby
reducing article vibrations and improving stability.
Consistent with yet another aspect of the invention, a discharge starwheel is
utilized to transfer
articles from the discharge end of an arcuate guide that opposes a label
transfer drum. The drum and
arcuate guide adhere a label to an article by cooperatively wrapping the label
around the article as the
article rolls between the drum and arcuate guide. In some applications,
careful control of configuration
of the pockets on the discharge starwheel can improve the stability of
discharged articles tiuough
reducing the spin imparted on articles by the label application process and/or
decelerating the articles
for pickup by a downstream discharge mechanism.
Consistent with still another aspect of the invention, a discharge starwheel
may be utilized
intermediate a label application station and a conveyor. The discharge
starwheel may include a
plurality of teeth defined about a perimeter thereof, with each tooth having a
profile that decreases the
separation between successive articles between the label application station
and the conveyor. By
reducing the separation between articles, greater stability on a conveyor may
be obtained, as adjacent
articles tend to support one another downstream of the label application
station.
These and other advantages and features, which characterize the invention, are
set forth in the
claims annexed hereto and forming a further part hereof. However, for a better
understanding of the
invention, and of the advantages and objectives attained through its use,
reference should be made to
the drawings, and to the accompanying descriptive matter, in which there is
described exemplary
embodiments of the invention.
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Brief Description of the Drawings
FIGURE 1 is a top plan view of a labeling apparatus consistent with the
invention.
FIGURE 2 is a block diagram of the primary components of the label application
assembly of
Fig. 1.
FIGURE 3 is an enlarged top plan view of the label applicator drum of Fig. 1,
with portions
thereof cut away.
FIGURE 4 is a side cross-sections! view of the label transfer drum of Fig. 3,
taken along line
4-4.
FIGURES SA-SD are functional top plan views of the label transfer drum of Fig.
3 at different
rotational positions thereof, illustrating the steps in cutting a label,
applying adhesive thereto, and
transferring the label to a container.
FIGURE 6 is a block diagram of the control system for the labeling apparatus
of Fig. 1.
FIGURE 7 is a flowchart illustrating a dynamic web registration process for
the labeling
apparatus of Fig. 1.
FIGURE 8 is a flowchart illustrating the steps of a startup process for the
labeling apparatus of
Fig. 1.
FIGURE 9 is a timing diagram illustrating the timing of operations in the
labeling apparatus of
Fig. 1.
FIGURE l0A is a side cross-sectional view of one of the carrier mechanisms of
Fig. 1, with
only one article carrier illustrated for simplicity.
FIGURE l OB is a functional top plan view of the carrier mechanism of Fig.
10A, with only
one article carrier illustrated for simplicity, and with the hub thereof
removed to facilitate viewing of
the caroming mechanism utilized thereby.
FIGURE l OC is a functional side elevational view of the carrier mechanism of
Fig. 10A.
FIGURES 1 lA-11E are functional top plan views of the carrier mechanism of
Figs. 10A-lOC
at different rotational positions thereof, illustrating the transfer of
articles from a conveyor to an
applicator drum.
FIGURE 12 is a top plan view of an alternate labeling apparatus to that shown
in Fig. 1,
utilizing a turret article transport mechanism.
FIGURE 13 is a top plan view of a labeling apparatus consistent with the
invention.
FIGURE 14A is a top plan view of the label transfer drum and adhesive
applicator of Fig. 13,
with portions thereof cut away.
FIGURE 14B is an enlarged fragmentary top plan view of a cutter assembly
bushing in the
label transfer drum of Fig. 14A.
FIGURES 15A and 15B are functional top plan views of the label transfer drum
and adhesive
applicator of Fig. 14A, respectively illustrating the application of adhesive
to leading and trailing ends
of a label.
FIGURE 16 is a top plan view of the flow starwheel of Fig. 13, with resilient
.
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FIGURE 17 is a cross-sectional view of the flow starwheel of Fig. 16, taken
through lines 17-
17.
FIGURES 18A-18F are functional top plan views of the article infeed portion of
the labeling
apparatus of Fig. 13, illustrating the transfer of articles from the conveyor
to the infeed starwheel by the
flow starwheel.
FIGURES 19A-19D are functional top plan views of the article discharge portion
of the
labeling apparatus of Fig. 13, illustrating the transfer of articles from the
drum to the conveyor by the
discharge starwheel.
FIGURE 20 is a functional top plan view of the article discharge portion of
the labeling
apparatus of Fig. 13, illustrating the position of an article at a plurality
of points dwing the rotation of
the discharge starwheel.
FIGURE 21 is a top plan view of an alternate flow starwheel to that of Figs.
16 and 17,
implementing a resilient outer surface.
FIGURE 22 is a top plan view of another alternate flow starwheel to that of
Figs. 16 and 17,
implementing an inflatable body.
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Detailed Description
Turning to the Drawings, wherein like numbers denote like parts throughout the
several views,
Fig. 1 illustrates a labeling apparatus 10 consistent with the principles of
the invention. Apparatus 10 is
principally used to apply labels in a continuous fashion to a plurality of
articles 2 conveyed via an
article transport mechanism (e.g., a conveyor 22) from an entrance end 22a to
an exit or discharge end
22b. Apparatus 10 may be utilized with any number of article designs,
including various containers
with upright cylindrical portions, e.g., cans or bottles. The articles may be
suitable for use in packaging
beverages or foodstuffs, or any other type of packaged goods. For example, one
suitable application of
apparatus 10 is in applying labels to single-serving plastic soft drink
bottles, among others.
Articles 2 are conveyed past a label application assembly or mechanism 25
using a pair of
carrier mechanisms 400, 460, which are described in greater detail below.
Carrier mechanism 400
transfers articles 2 along an arcuate guide 14 to a label application station
20 disposed opposite
assembly 25. As will be discussed in greater detail below, carrier mechanism
400 operates to vary the
separation between successive articles passing through guide 14 between a
first separation proximate
entrance end 22a to a second separation proximate station 20 that is dependent
upon the separation
between labels provided on an applicator drum 100 in label application
assembly 25.
Application station 20 includes an arcuate guide 18 against which the articles
are compressed
by applicator drum 100 as labels are applied to the articles. Guide 18
includes a resilient friction
surface to impart a rolling action to the articles as the articles pass
through the label application station
such that labels are wrapped around the articles.
Carrier mechanism 460 performs essentially the same operation as carrier
mechanism 400
except that mechanism 460 operates to decelerate articles from a first
predetermined separation that
matches the separation of labels on applicator drum 100 to a second
predetermined separation suitable
for transport on conveyor 22. By doing so, this arrangement imparts greater
stability to discharged
articles by minimizing relative movement of the articles to the conveyor at
the discharge end of track
16.
Labels are supplied to applicator drum 100 from a web supply 30 supplying a
web 4 of
labeling material. Typically, web 4 includes a pre-printed polymer material
formed of a polymer such
as polyethylene. Other materials, including polymers such as polypropylene and
polystyrene (among
others) may also be used, although polyethylene has the additional advantage
in that it is significantly
less expensive than other polymers. Polyethylene fiLn tends to be more
stretchable than other polymer
films. However, due to the constant tension provided in web 4 by the unique
design of label application
assembly 25, the stretchability of this material does not adversely impact the
quality of labels supplied
by the assembly.
Web supply 30 includes a pair of supply rolls 32, 34 that supply web 4 to a
measuring roller
assembly 50. Only one of supply rolls 32, 34 is active at any time, and a
conventional change-over
mechanism (not shown) may be used to switch between the rolls with minimal
down time.
Measuring roller assembly 50 operates as a linear feed rate sensor using a
free-wheeling roller
52 coupled to a rotational position sensor 54. Roller 52 has a known diameter
such that the linear
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velocity of the outer surface thereof, and thus the linear feed rate of the
web, may be calculated directly
from the rotational speed of the roller. Sensor 54 may be any known rotational
position sensor, e.g., an
optical encoder.
Web 4 proceeds from assembly 50 to a web tracking control assembly 60 that is
utilized to
maintain lateral alignment of the web in assembly 25. Web 4 then proceeds to a
registration sensor
station 70 that detects the position of registration marks disposed on the
web. Station 70 includes a
roller 72 and a registration sensor 74 disposed opposite roller 72 at a
lateral position relative to the web
to detect registration marks disposed thereon. Registration sensor 74 may be
positioned at practically
any point between web supply 30 and applicator drum 100 in the alternative.
It should be appreciated that registration marks may take any number of forms,
whether
printed or otherwise formed in web 4. Printed registration marks may be
disposed outside of a visible
area on the labels, or may be integrated within the design printed on a label.
Moreover, registration
marks may be disposed at a cutting position for a label, or may be separated
therefrom by a
predetermined distance. Other registration mark designs may be utilized in the
alternative.
1 S From registration station 70, web 4 proceeds to the surface of applicator
drum 100, where an
attraction mechanism disposed on the outer surface of the drum applies a
controlled tension to the web.
Moreover, a pair of movable cutter assemblies 130, 170 disposed on drum 100
operate to sever labels
from web 4 as each assembly 130, 170 passes a fixed knife 82 in a cutting
station 80. As will be
discussed in greater detail below, the rate at which web 4 is supplied via web
supply 30 is controlled
relative to the rotation of applicator drum 100 (which is driven by a main
drive motor 85) such that a
predetermined length of the web is disposed forward of a cutter assembly 130,
170 as the assembly
passes fixed knife 82, whereby individual labels are severed from web 4 in a
controlled manner.
An adhesive station assembly 90 is disposed beyond cutting station 80 to apply
adhesive to
leading and trailing ends of each label using an application roller 92. As
will be discussed in greater
detail below, adhesive is applied to the leading edge of the label prior to
severing the label from web 4,
such that the tension within the web assists in maintaining the leading edge
of the label on the outer
surface of applicator drum 100 as adhesive is applied to the leading edge
thereof.
After adhesive is applied to the leading and trailing edges of a label, the
label is presented to
an article 2 via rotation of applicator drum 100, whereby rotation of
applicator drum 100 through label
application station 20 wraps the label around the article as the article rolls
against guide 18.
Label Application Assembly
Fig. 2 illustrates the primary components involved in supplying and severing
labels from web
4 in a controlled manner. Assembly 25 is under the control of a control system
200, which operates to
control the supply rate of web 4 relative to the rotation of applicator drum
100. Applicator drum 100 is
rotated via a main drive motor 85 coupled to the drum via a linkage
diagrammatically represented at 86.
The rate of rotation of drum 100 is measured via a rotational position sensor
88, which may be any type
of known rotational position sensor such as an optical encoder. Control system
200 also receives the
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output of sensor 54 to generate therefrom a measurement of the linear feed
rate of web 4. Control
system 200 also receives a registration signal from registration sensor 74.
In response to these inputs, control system 200 controls a drive motor 36 to
control the rate of
rotation of supply roll 32, and thus the feed rate of web 4. Drive motor 36 is
typically a servomotor,
and as such, additional input is provided to control system 200 via a
rotational position sensor 38 (e.g.,
an optical encoder) which provides feedback from drive motor 36. It should be
appreciated that a
similar servomotor may also be used to drive supply roll 34 in a similar
manner.
Assembly 25 is thus configured in a master-slave relationship, whereby the
supply rate of web
4 is controlled relative to the speed of applicator drum 100. In the
alternative, a reverse configuration
may be provided wherein the rate of rotation of applicator drum 100 is
controlled relative to the feed
rate of web 4. In addition, it may be desirable in some applications to
control both the feed rate of web
4 and the rotational rate of applicator drum 100. Therefore, the invention
should not be limited to the
configuration illustrated herein.
One embodiment of the invention utilizes a servomotor with a built-in encoder
such as the
l5 FSM 460 servomotor from Centurion as the drive motor 36 and rotational
position sensor 38, with an
HR 625-500-x-BEI Optical Encoder from Dynapar coupled to a 50.93 mm diameter
measuring ruler
used for rotational position sensor 54 and measuring roller 52, a Model NT-6
Optical Sensor available
from Sick for registration sensor 74 and an HR-625-2500-x-BE1 Optical Encoder
from Dynapar used
for rotational position sensor 88. Rotational position sensor 54 may be geared
with a ratio of 80/40 to
measuring roller 52 to provide a resolution of 0.0393 mm/count or 25.5
counts/mm. It should be
appreciated that these components are merely examples of a wide variety of
other components that may
be utilized in assembly 25 in the alternative.
Figs. 3 and 4 illustrate applicator drum 100 in greater detail. Applicator
drum 100 includes a
rotatable drum body 102 configured to rotate about a fixed shaft 120.
Rotatable body 102 includes an
outer surface 104 having a plurality of vacuum ports 106 disposed thereon and
supplied with a source
of vacuum and/or positive pressure through a set of distribution channels 108
coupled to a vacuum port
109 (Fig. 4).
Two sets of raised pads I 10, 111 and 112, 113 are disposed on outer surface
104 to receive
leading and trailing edges of a label as the label passes an adhesive
application station so that adhesive
may be applied to the opposing edges of the labels. An applicator roller (not
shown in Figs. 3 and 4) is
offset from outer surface 104 such a distance that label material supported on
any pad 110-113 will be
compressed against the roller, but material disposed between the pads will
not. Thus, adhesive is
applied only to the material supported on a pad.
As will become more apparent below, pads 110 and I 11, and pads 112 and 113
are separated
from one another around the circumference of drum 100 at a distance that is
greater than the length of
the labels so that the leading edge of each label may have adhesive applied
thereto prior to severing the
label from the web. This reduces the likelihood of a label sticking to the
adhesive roller due to the
additional tension provided by the unsevered web.
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It is desirable for drum body 102 to be a changeable component such that
different
predetermined lengths of labels may be accommodated in apparatus 10. Different
lengths of labels are
accommodated by utilizing different relative spacing beriveen pads 11 U and I
1 t , and between pads 112
and 113. It may also be desirable to enable leading pads 110, 112 to be
removed from outer surface
104 and positioned at various points thereon to support different label
lengths. The separation of pads
110 and 112, and of pads 112 and I 13 will vary depending upon a number of
factors, including the
desired length of labels, as well as the relative positions of cutting station
80 and adhesive station
assembly 90. Determination of the desired separation for any given combination
of parameters is well
within the ability of one of ordinary skill in the art.
As shown in Fig. 3, two sets of pads, pads 110 and 111, and pads 112 and 113,
are provided
around the circumference of rotatable body 102, each matched with a cutter
mechanism 130, 170. It
should be appreciated that any number of cutter mechanisms and associated
raised pads may be
disposed around the circumference of drum body 102 in the alternative.
As best shown in Fig. 3, cutter mechanism 130 (which is configured in a
similar manner to
cutter mechanism 170) includes a rocker body I32 pivotally mounted to pivot
about a shaft 134 that
extends parallel to shaft 120. A spring 136 (Fig. 4) is mounted concentrically
with shaft 134 to
compensate for temperature expansion in the bearing (not shown) through which
the rocker body is
pivotally mounted about shaft 134. As shown in Fig. 3, at one end of body 132
is disposed a cam
follower assembly 140 including a roller 142 rotatably mounted about an axle
143. Axle I43 is secured
via a bolt 144 to a follower body 145, and a flexible boot 146 seals the
assembly. Cam follower
assembly 174 of cutter mechanism 170 (Fig. 4) is configured similarly to
assembly 140.
Knife assembly 150 is disposed at the opposite end of rocker body 132 from cam
follower
assembly 140. A knife blade 152, having an edge 153, is secured to the end of
rocker body 152 via a
bolt or other securing mechanism 154. Edge 153 of knife blade I 52 projects
through an opening 114 in
outer surface 104 of body 102, immediately following trailing pad 111 around
the circumference of
body I 02.
A spring assembly 160 including a spring 162 extends perpendicular to shaft
120 and biases
cutter assembly 130 toward an extended position, with knife blade 152
projecting through opening I 14
beyond outer surface 104. A set screw 164 controls the tension of spring 162.
Roller 142 of cam follower assembly 140 rides along a cam 122 disposed on the
outer surface
of shaft 120. Cam 122 is circular in cross section with the exception of a
recessed portion 124.
Recessed portion 124 may have any number of profiles, e.g., a flattened
profile as illustrated in Fig. 3.
Recessed portion 124 is angularly oriented such that roller 142 engages the
portion when knife blade
152 of knife assembly 1 SO is directly opposite fixed knife 82 of cutting
station 80, thereby extending
the knife blade at this position to shear a label from the web.
Figs. SA-SD illustrate the steps in severing a label from web 4 and applying
the label to an
article 2 presented at label application station 20. As shown in F'ig. SA, a
leading edge 4a of web 4 is
shown as fed forward of knife 152 of cutter mechanism 130 to a position where
the leading edge
slightly overlaps pad 110 when the pad is disposed opposite roller 92 of
adhesive application assembly
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90. When in this position, drum 100 rotates so that pad I 10 sweeps under
roller 92, sandwiching web
4 and applying adhesive 6 to the web proximate leading edge 4a. At this point,
the label is still
unsevered from the web, so the tension provided via the amaction mechanism
generated by the vacuum
ports in outer surface 104 of drum 100 assists in attracting leading edge 4a
to the outer surface of the
drum, and thus away from adhesive roller 92. As such, this often eliminates
the need for a blow off
mechanism on the adhesive roller or the need for an increased level of vacuum
proximate the leading
edge as is required on many conventional designs.
As also shown in Fig. SA, knife blade 152 of cutter mechanism 130 is retracted
as roller 142
rides along the raised portion of cam I22 on shaft 120.
Next, as shown in Fig. SB, drum 100 has rotated to the point at which knife
blade 152 is
directly opposite fixed knife 82. Web 4, which is fed at a slower rate than
the rate of rotation of drum
100, has been fed to the desired label length such that the precise point at
which the web is to be
severed is located between knife blade 152 and fixed knife 82. With roller 142
of cutter mechanism
130 contacting the recessed portion 124 of cam 122, cutter mechanism 130 is
pivoted about shaft 134
to extend knife blade 152, and thereby provide a shearing action with fixed
knife 82 to sever a label 5
from web 4.
Next, as shown in Fig. SC, upon further rotation of drum 100, pad 111 sweeps
under adhesive
roller 92 to apply adhesive 6 to the trailing edge 4b of label 5. In addition,
at this time an article 2 is
brought into contact with leading edge 4a of label 5 such that the adhesive
thereon adheres to article 2.
The label is pinched between article 2 and outer surface 104 and is rolled
about its longitudinal axis to
wrap label 5 around the article. As may also be seen from this figure, a new
leading edge 7a is formed
for web 4.
Next, as shown in Fig. SD, label 5 has almost completely wrapped around
article 2, and will
continue to do so until the adhesive 6 proximate trailing edge 4b of label 5
contacts the article. In
addition, the new leading edge 7a of web 4 is at approximately the same
position as leading edge 4a
was in Fig. SA, immediately prior to application of adhesive by virtue of
roller 92 sandwiching the web
against a leading pad 112. Upon further rotation, cutter mechanism 170 will
therefore sever another
label from web 4, and the process will repeat. Thus, with this configuration,
drum 100 processes two
labels during each full rotation of the drum. With other numbers of matched
cutter mechanisms and
raised pads, different numbers of labels may be handled by drum 100 in the
manner described herein.
Control system 200 is illustrated in greater detail in Fig. 6. The control
system is primarily
controlled via a CPU controller 202, which may be, for example, a CSM/CPU 502-
03- 853-03 digital
processor from Gidding & Lewis, among others.
An operator interface and controls block 204 is shown interfaced with
controller 202 through a
discrete input module 206. Block 204 provides user interface for apparatus 10
with a operator, e.g.,
outputting status information to an operator through a video display and/or
through various control
panel indicators, as well as providing various operator controls, including
"Start" and "Stop" buttons,
"Jog" and "Auto" buttons, Label Feed "On" and "OfF' Buttons and Adhesive "On"
and "Off' buttons,
among others.
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Controller 202 provides output through a discrete output module 208 to
generate a digital
signal speed control to a main drive frequency control block 210 that controls
the main drive motor 85
to operate in "fast" or "slow" modes. Block 210 receives a signal from a
potentiometer 211 that
controls the overall speed of the main drive, and is used by an operator to
match the running speed of
assembly 25 to the supply of articles. Moreover, block 210 outputs a control
signal to analog speed
signal control block 212 for controlling the speed of a conveyor motor 214
coupled to conveyor 22
(Fig. 1 ).
Controller 202 also interfaces with the various sensors utilized to provide
web registration via
an I/O module 216. Specifically, module 216 provides an interface between
controller 202 and each of
servo amplifier 42, encoders 54, 88 and registration sensor 74. Servo
amplifier 42 is coupled to servo
motor 36 and its associated encoder 38 (not shown in Fig. 6). Also shown is
the servo amplifier's
connection to a second servo motor 40 which drives a web supply roll 34 in a
similar manner to servo
motor 36. It should be appreciated that only one of motors 36, 40 is driven at
a time based upon which
supply roller is being run through assembly 25.
Module 216 also provides an interface with controller 202 to a vacuum drive
frequency
control block 218 that drives a vacuum motor 220. It is through this
arrangement that the level of
vacuum (or attraction) supplied to the outer surface of applicator drum 100 is
controlled.
Blocks 210, 212 and 218 are all coupled to a main power source 222. Power is
also supplied
via block 222 to an oil pump motor 224, a turret up/down motor 226 (if so
equipped) and a transformer
228. Transfonmer 228 provides the power signals for a bus 203 coupled between
controller 202, servo
amplifier 42, a power supply 230, web tracking control station 60, adhesive
applicator 90 and an air
conditioner/heat exchanger block 232. Power supply 230 provides power to
operator interface and
machine controls block 204 and input module 206. Web tracking control station
60 receives input from
a web guide sensor 62 and outputs control signals to an actuator 64 to provide
lateral alignment of the
web, in a manner generally understood in the art. Adhesive applicator 90
provides control signals to a
bar heater 94 and base heater 96, which respectively heat applicator roller 92
and a tank in applicator
90. These latter components are used in a number of conventional labeling
apparatus designs, and will
not be discussed in greater detail herein.
Fig. 7 illustrates a closed loop control algorithm 250 utilized in controller
202 to control servo
motor 36 to provide web registration consistent with the invention.
Algorithm 250 utilizes a plurality of computational blocks 252, 254, 256, 258,
260, 262 and
264 to drive a control signal to servo amplifier 42 to operate servo motor 36.
Blocks 252-256 are
clocked by the leading edge of the output of registration sensor 74, while
blocks 258, 260, 262 and 264
are clocked by a clock signal represented at 266, e.g., a 2 kHz clock signal.
Control algorithm 250 attempts to maintain a ratio of pulses between drum
positioning
encoder 88 and linear feed rate encoder 54 (designated El and E2) according to
the equation:
R~ = L~(nD(E2alEI ~)
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where Ro is the nominal ratio, Lo is the nominal label length, D is the
diameter of free wheeling roller
52, and EI o and E2o are the total numbers of pulses, respectively, for full
revolutions of encoders 88
and 54.
For each label n, block 252 receives the pulse train outputs (designated El
and EZ) of drum
positioning encoder 88 and linear feed rate encoder 54 to generate a
registration error signal E that is
the difference, expressed in pulses, between the position of the registration
mark on the label sensed by
the registration sensor 74 and the preset {or expected) position of the mark.
Block 254 calculates the length of a label n from registration mark to
registration mark in
pulses of the linear feed rate encoder 54 (designated E2"}. This information
is utilized in block 256 to
calculate a ratio between encoders 88 and 54 for the next label (n+l ) that is
corrected for the
registration error E, using the equation:
R~",,~ _ (E2" f E)lEI o
Block 258 calculates the actual ratio Ro of the number of pulses of each of
encoders 88 and 54
between time marks using the actual pulse trains from encoders 88 and 54,
i.e.:
Ra = dE2/dEl
Block 250 calculates a ratio error E, that is the difference between the
current ratio R" (i.e.
E2,~El o), and the actual ratio R", using the equation:
E, = R" - R"
In addition, a command for the servo motor such to achieve the actual ratio in
the next time
interval is calculated, using the equation:
R=RofE,
Next, block 62 generates from the command from block 260 the proportional and
integrated
feedback signals for controlling servo motor 36. This information is summed
with the derivative gain
feedback generated by block 264 based upon the feedback signal from servo
motor encoder 38
(designated E3). It should be appreciated that simultaneous use of integrated,
derivative and
proportional feedback signals is well known in the art. Moreover, it should be
appreciated that other
control algorithms which utilize the aforementioned equations may also be used
in the alternative.
A self teaching start-up routine 280, executed by controller 202 of control
system 200 to
initialize apparatus 10, is illustrated in greater detail in Fig. 8. Routine
280 configures apparatus 10 to
operate with a new roll of web material using a self teaching process that
often eliminates the
requirement in many applications for the label length to be manually input by
an operator. Routine 280
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is executed by an operator after the operator installs a new web roll and
feeds the leading edge of the
web into assembly 25. The routine begins in block 284 by advancing the web
(e.g., in response to user
input received from an operator through controls 204) through assembly 25
until the registration sensor
is in front of the first registration mark on web. At this time, the operator
hits a "Stop" button to
manually halt the apparatus. Next, in block 286, the web is advanced (e.g., in
response to user input
such as an operator depressing a "Start" or "3og" button) until the
registration sensor is proximate the
next mark on the web. Then, the operator again hits the "Stop" button to halt
the apparatus. During
blocks 284 and 286, the output of the registration sensor and linear feed rate
encoder are monitored to
determine the number of pulses between the marks, and thus, the nominal length
of the label (Lo) in
terms of the output of the linear feed rate encoder.
Next, in block 288, the web is advanced in response to user input from an
operator; however,
in this block, the controller automatically advances the web and attempts to
stop the web precisely at
the next registration mark without any additional operator intervention. At
this time, the operator may
also be requested to indicate to the system whether the automatic advance
successfully terminated
directly at the next registration mark.
Assuming that this operation was successful, in block 290 the controller
receives user input
from an operator to manually rewind and/or advance the web to the desired cut
position for the label
(e.g., in response to an operator depressing suitable "Rewind" and "Advance"
buttons). Next, the
operator depresses a button or otherwise indicates to the controller that the
cut position has been set.
During the manual rewind/advance, the controller monitors the linear feed rate
encoder output to set the
cat position in units of the linear feed rate encoder pulses relative to the
registration mark.
Next, in block 292, the controller attempts to operate the apparatus to cut
the first label based
upon the registration information calculated above for the web, e.g., in
response to suitable user input
from an operator. The controller halts the apparatus after the first label is
cut, and in block 294, waits
to receive acknowledgment from the operator that the label cut was acceptable.
If not successful, a
process similar to block 284-292 may be repeated, or the routine may terminate
with a failure indicated.
However, if successful, the controller stores the program in one of a
plurality of program storage
locations. After the program is stored, the apparatus is then ready to begin
processing articles using the
aforementioned closed loop control algorithm when suitable user input is
received from an operator.
The sequence of logic signals in apparatus 10 is illustrated at 300 in Fig. 9,
where each signal,
timed according to the rotational position of the drum (i.e., from 0 to 360
degrees, with each complete
rotation, or cycle, being designated A-D). A container detector signal 320 is
shown being latched to
"on" upon receipt of a each container into apparatus 10.
For example, during initiation of a label feed operation during a cycle A, a
label feed logic
signal 3I0 may be enabled, typically in response to an operator depressing an
label feed "On" button on
the apparatus, or in response to a signal provided by an external device such
as a sensor that detects
when one or more containers or articles are about to be received in the
apparatus for labeling. Upon
container detector signal 320 being latched to "on", an internal label feed
logic latch signal 330 then
latches prior to the start of cycle B, so that it is effectively delayed one
cycle from the label feed logic
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signal. Then, after the knife has passed the cutting position (the 0 degree
position) at the start of cycle
B, a servomotor command signal 330 is asserted to start drive motor 36. The
speed profile of drive
motor 36 is illustrated at 360, including a minimal possible acceleration
phase 362 that is encountered
from about 15 to about 115 degrees, a minimal overspeed necessary phase 364
from about 115 to about
270 degrees, a deceleration to nominal speed phase 365 from about 270 to about
285 degrees and a
nominal speed phase 366 thereafter that is related to a machine speed of Vp =
CPM (containers per
minute) x L (label length).
Fig. 9 also illustrates a adhesive roller logic signal 370 that is initially
illustrated as enabled to
reflect that adhesive should be applied to any labels processed by apparatus
10. If adhesive application
is enabled, immediately after the servomotor command signal 340 is asserted,
an adhesive roller logic
signal 380 is applied, and an adhesive roller solenoid (represented by signal
390) is asserted about 90
degrees delayed relative to signal 380 (so that adhesive may be applied to the
last label whenever a
labeling is stopped, as described below).
Assuming now, for example, that label feed logic signal 310 is disabled during
cycle A. With
IS the label feed logic signal 330 delayed one cycle relative to signal 310,
signal 330 is not unlatched until
just prior to the completion of cycle B. Then in cycle C, the speed profile
360 of drive motor 36 is
altered to perform a stop down, including a minimal deceleration phase 367
from about 90 degrees to
about 120 degrees and a rewind phase 368 that serves to withdraw the web a
predetermined distance
(e.g., about 2-3 mm behind the knife blade) and thus maintain the web in a
ready state just beyond the
still-rotating drum. After a rewind, the servomotor command signal 340 is shut
off, and the drive motor
speed goes to null in phase 369.
Also during cycle B, once label feel logic signal 330 is unlatched, adhesive
roller logic signal
380 is unlatched to inhibit adhesive application, resulting in (after a delay
of about 120 degrees to
permit adhesive to be applied to the last label) the adhesive roller solenoid
signal 390 being deasserted.
Fig. 9 additionally illustrates a restart of label application in cycle D,
upon label feed logic
signal 310 being enabled during cycle C. In this instance, label feed logic
signal 330 is asserted just
prior to the start of cycle D, and servomotor command signal 340 is applied to
start drive motor 36 and
cause the drive motor to follow the speed profile illustrated at 360. However,
in this cycle, the adhesive
roller logic signal 370 has been disabled, so regardless of whether the
internal roller logic signal 380
being set to "on", solenoid signal 390 is not asserted, and no adhesive is
applied to a label.
It should be appreciated that development of suitable control programs to
implement the
functionality described herein, and in particular in connection with Figs. 7-
9, is well within the abilities
of one of ordinary skill in the art. Therefore, no additional discussion
thereof is provided herein.
Carrier Mechanisms
Figs. l0A and l OB illustrate carrier mechanism 400 in greater detail. It
should be appreciated
that carrier mechanism 460 may be similarly configured, albeit with a
different cam profile suitable for
its function, as will become more apparent below.
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In general, each carrier mechanism is configured to sequentially transport
articles such as a
beverage containers along an article engaging surface of a guide and between
first and second stations,
while varying a predetermined transport parameter for the articles. In the
embodiment described
herein, the predetermined transport parameter is the pitch of the articles -
that is, the separation
between successive articles. The articles are carried by article carriers
disposed at the ends of arms that
are pivotably coupled to a central, rotating hub. A pitch varying mechanism
utilized by each carrier
mechanism relies on a caroming action to rotate the arms relative to the
rotating hub, whereby the pitch
between transported articles may be controlled principally through rotary
motion to provide reliable
high speed operation for high throughput machines.
The first and second pitches may each be dependent upon a number of factors,
e.g., the linear
and/or rotational velocity of articles, the size of the articles, etc. As
such, the parameters of the
surrounding stations that may need to be matched to provide controlled pitch
with a carrier mechanism
may not be cast in terms of separation, but may instead be based upon velocity
or another parameter, as
will become more apparent below. However, given that pitch, velocity, article
size, etc. are interrelated
with one another, it will be appreciated that a carrier mechanism consistent
with the invention may
alternatively be configured to control other parameters.
As shown in Fig. 10A, carrier mechanism 400 includes a shaft housing 402
having a drive
shaft 404 rotatably mounted therein via bearings 406. A cam housing 408 is
fixedly coupled to shaft
housing 402, and a hub 409 is fixedly coupled to drive shaft 404 to
cooperatively rotate therewith.
As shown in Fig. 1 la, for example, a set of five article carriers 410x, 410b,
410c, 410d and
410e are evenly spaced around hub 409 in the illustrated embodiment. Only one
such article carrier
410a is shown in Figs. l0A and l OB to simplify the illustrations. However, it
should be appreciated
that any number of article carriers may be utilized on can; ier mechanism 400
consistent with the
invention.
Article carrier 410a includes upper and lower arms 412, 414 that respectively
terminate with a
gripping mechanism such as a pair of pockets 413, 415 integrally formed
thereon for receiving an
article 2 supported on conveyor 22. Pockets 413, 415 are sized and configured
to circumscribe a
cylindrical portion of article 2, and may utilize different profiles for other
article configurations in the
alternative. Moreover, other gripping mechanisms may be utilized as an
alternative to pockets 413, 415
depending upon the type of article being transported. Moreover, in other
embodiments, multiple
axially-displaced pockets may not be required to reliably engage articles.
As best shown in Fig. 10A, arms 412, 414 are fixedly mounted on a rocker shaft
420 that is
pivotably coupled to hub 409 through bearings 422. Rocker shaft 420 projects
through apertures in a
phaseabIe lid 425 and a seal lid 426 that overlap hub 409 and seal the inner
components thereof.
A linkage member 428 is fixedly mounted at the lower end of rocker shaft 420,
with a cam
follower 429 disposed at a distal end thereof. 1n the illustrated embodiment,
cam follower 429 is
configured as a roller that engages an inwardly-facing wall 442 in cam housing
408 that functions as a
cam for carrier mechanism 400.
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As best shown in Fig. l OB, cam follower 429 and linkage member 428 are
circumferentially
spaced about rocker shaft 420 from arms 412, 414 to form an acute angle a
relative thereto. In the
illustrated embodiment, a is approximately 60 degrees, although other angles
may be used in the
alternative.
In addition, as best shown in Fig. l OC, it may be desirable to provide an
angular offset
between arms 412, 414 about rocker shaft 420 so that arm 412 slightly leads or
trails arm 414 and
thereby induces a controlled tilt to an article 2 engaged by pockets 413, 415.
By doing so, improved
label alignment, and a reduced likelihood of label misalignment, may result
due to the ability to
compensate for any imperfections in the containers and/or machined parts that
might otherwise induce
improper tilting of containers carried by the mechanism. In the illustrated
embodiment, the angular
offset is provided by manipulation of phaseable lid 425 (Fig. l0A), which is
configured to be secured at
different angular positions within a defined range to vary the angular offset
between arms 412 and 414.
Moreover, the angular offset of arms 4I2, 414 is typically set to impart a
tilt to an article retained
thereby to an angle (3 offset from vertical of about +/- 1 degree (the amount
of tilt is exaggerated in Fig.
l OC for illustrative purposes). Other degrees of tilt may be utilized in
other embodiments, and may
often be determined empirically based upon factors such as the type and
configuration of the articles,
among other factors.
Returning to Fig. I OA, hub 409 is considered to rotate about a first axis 451
defined along the
longitudinal axis of drive shaft 404, while article carrier 410 is considered
to pivot about a second axis
452 defined along the longitudinal axis of rocker shaft 420. In operation,
therefore, as hub 409 rotates
about first axis 451 in response to rotation of drive shaft 404, cam follower
429 rides along cam 442 to
controllably pivot article carrier 410a about second axis 452. As a result,
the angular velocity of article
Garner 410a is controllably varied relative to the angular velocity of hub
409. It should be appreciated
that a multitude of other known cam and linkage arrangements may be utilized
in the alternative to
impart a controlled angular offset of each article carrier relative to hub
409.
The profile of cam 442 is selected to provide a controlled pitch at first and
second positions of
carrier mechanism 400. For example, as shown in Fig. 11 A, the first position
is the position at which
an article carrier (e.g., article carrier 410b) engages an article (e.g.,
article 2b} on conveyor 22. The
second position is the position at which an article carrier (e.g., article
carrier 410a) deposits an article
(e.g., article 2a) against the outer surface of applicator drum 100.. The
pitch in this application is
defined as the distance between center points of successive articles.
At the first position, the desired pitch is based upon the separation between
articles supplied to
apparatus 10 via conveyor 22. To assure a continual supply of articles, the
articles are typically
penmitted to "queue up" on the conveyor in an abutting relationship. As such,
the separation between
articles is directly related to the size of each article. With each article
being cylindrical in shape, the
separation between articles is the sum of the radii of successive articles. In
addition, assuming each
article has the same radius, the separation may be expressed in terms of twice
the radius of an article,
which is equal to the diameter of the article, designated herein as D,,. Thus,
the desired pitch at the first
position, S,, is therefore:
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S, = D,,.
At the second position, the desired pitch is equal to the separation between
the leading edges
of labels supplied on the outer surface of applicator drum 100. Assuming an
applicator drum that
provides n labels evenly spaced about the drum's outer surface, the separation
at the second position,
S1, would thus be equal to the circumference of the drum (which is equal to
mimes the diameter of the
drum, DD) divided by the number of labels n, or.
SZ=(~xDdln
Thus, for an applicator drum that supplies two labels per rotation thereof,
the desired pitch at
the second position is:
SI = ~J2 x Do.
To achieve the desired separations at the fast and second positions, it may
also be desirable to
configure the cam profile based upon the desired angular velocity of the
article carriers relative to the
processing rate of apparatus 10. For example, at the first position, it is
typically desirable to match the
angular velocity of the article carriers with the speed of incoming articles
supplied to carrier mechanism
to prevent line vibration and its associated problems. Moreover, to achieve
the desired separation at the
second position, the angular velocity is typically related to the angular
velocity of the applicator drum.
It should be appreciated that calculation of the desired angular velocity
profile for the article earners
based upon the desired separations is well within the abilities of one of
ordinary skill in the art.
With carrier mechanism 400 utilizing five article carriers 410a-410e, and with
applicator drum
100 applying two labels per rotation, the hub of carrier mechanism 400 is
coupled to applicator drum
100 and drive motor 85 to provide a 1:2.5 gearing ratio between mechanism 400
and applicator drum
100, whereby applicator drum 100 rotates five times for every two rotations of
mechanism 400.
Also, as shown in Fig. l OB, for example, the cam profile of cam 442 defines
two regions
segregated at points A and B. The first region, extending counter-clockwise
from point A to point B,
has a fixed radius r, that maintains a constant angular velocity for each
article carrier having its
associated cam follower 429 disposed therein. Coupled with the fixed gearing
ratio between the carrier
mechanism and the applicator drum, the desired pitch at the second position is
assured.
In the second region extending counter-clockwise from point B to point A,
however, an article
carrier is controllably decelerated to reduce the pitch of an article carrier
proximate the first position to
match that of the incoming articles, then accelerated to return to the pitch
of the article carrier to match
that of the labels on the applicator drum. The point in which the cam profile
switches from decelerating
the article carrier to accelerating the article carrier is labeled as point C,
and is typically disposed at an
angular position that orients the article carrier at the first position
(offset an angle a from cam follower
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429). The cam profile therefore may decrease from point B to a minimum radius
r, proximate point C,
and then increase back to radius r, proximate point A.
Typically, the variations in the cam profile form smooth transitions to
facilitate rapid
movement of the cam followers along the cam. It should be appreciated that the
design of a cam profile
that meets the above constraints is well within the abilities of one of
ordinary skill in the art, and may, if
desired, be determined in whole or in part empirically. Moreover, any number
of alternate profiles that
provide the required pitches at the first and second positions may also be
used consistent with the
invention.
It should be appreciated that for carrier mechanism 460 (Fig. 1 }, which
operates to transport
articles from applicator drum to conveyor 22 at the discharge end 22b of
labeling apparatus 10, an
essentially complementary cam profile may be used, which transports articles
from a first position that
matches the separation of articles being discharged by applicator drum 100
(essentially the same
separation as the second position for carrier mechanism 400) to a second
position that matches the
desired separation of articles discharged onto the conveyor (essentially the
same separation as the first
position for carrier mechanism 400). For carrier mechanism 460, it is
desirable to return articles onto
conveyor 22 at the same linear velocity as that of the conveyor to prevent any
slippage or possible
tilting of the articles as they are received onto the conveyor.
Returning to Fig. 1, it is important to note that in the illustrated
embodiment, each article
cannier is configured to transport an article along an article engaging
surface defined by fixed guide 14,
with the pocket disposed at the end of the article carrier merely operating to
"push" the article along the
guide. 1n many embodiments, for example, it may be desirable to abut or engage
articles without
actually gripping the articles (e.g., applying a compressive force to opposing
sides of the articles or
otherwise restraining the articles from motion in all directions). Instead,
articles may effectively be
trapped between the pockets and the guide so that the articles tend to "ride"
along the guide under a
motive force applied by the pockets - that is, the guide principally
determines the path of travel for the
articles, while the pockets simply accelerate and/or decelerate the articles
as they travel along the guide.
In different applications, it may be desirable to permit the articles to
either roll or slide along the guide
in a controlled manner (e.g., by selecting a material for the article
engagement surface having
appropriate frictional properties).
By cooperatively transporting the articles using the guide to determine the
path of travel, the
need for movable gripping mechanisms is often eliminated. As such, complexity
may be reduced, often
reducing cost and improving reliability. Moreover, higher speed operation is
typically possible since
the additional components, movement and coordination that would otherwise be
required to ensure that
articles are securely gripped and released at appropriate times would likely
limit the overall maximum
operational speed of a gripping-type article carrier.
Returning to Figs. 1 IA-1 IE, the sequence of transport for a plurality of
articles 2a, 2b, 2c, 2d,
and 2e is illustrated. As shown in Fig. 11A, article 2a is being discharged
onto the surface of applicator
drum 100 by article carrier 410a, with articles 2b, 2c and 2d queued up on
conveyor 22 waiting to be
transported to drum 100. Article carrier 410b has engaged article 2b, with
article carrier 410c
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beginning to be decelerated via the cam profile to match the linear velocity
thereof with that of article
2c. Next, as shown in Figs. I 1 B, I I C and 11 D, article carrier 4 I Ob is
accelerated by the cam profile to
increase the separation between article 2b and the following article 2c, while
article carrier 410c
continues to be decelerated to match the linear velocity with that of article
2c. Finally, in Fig. 11E,
article carrier 410b has reached the second position, whereby the article
carrier engages article 2b
against a label disposed on the outer surface of applicator drum 100 with the
desired pitch and in proper
alignment with the label. Moreover, article carrier 410c engages article 2c in
the first position in the
same manner as described above for article carrier 410b and article 2b in Fig.
I IA. Continued rotation
of carrier mechanism 400 results in the same sequential controlled
deceleration and acceleration of each
article carrier 410a-410e so that articles are continuously transferred to
applicator diem 100 with the
requisite pitch therebetween.
It will be appreciated that carrier mechanism 460 operates in a complementary
manner to
transport articles from applicator drum 100 and hack onto conveyor 22.
Moreover, it should be
appreciated that various modifications may be made to either of carrier
mechanisms 400, 460 consistent
with the invention.
Alternate Embodiments
It will be appreciated by one skilled in the art that the label application
assembiies and carrier
mechanisms described herein may be utilized independently of one another. For
example, as shown in
Fig. 12, a labeling apparatus 500 may include a label application assembly 25'
which includes a web
supply 30', measuring roller assembly 50', web tracking control assembly 60',
registration sensor
station 70', cutting station 80', adhesive station assembly 90' and applicator
drum 100'. Each
component in label application assembly 25' may be configured similarly to the
corresponding
unprimed components in label application assembly 25 of labeling apparatus 10
of Fig.l, or may
include any of the alternatives described above for any of such components.
Apparatus 500, however, includes an alternate article transport assembly to
the arrangement of
carrier mechanisms and conveyor for apparatus 10 of Fig. 1. Specifically,
apparatus 500 includes a
conveyor 502 that transports articles to and from apparatus 500. Articles 2
are received from conveyor
502 using a feed screw 510 that provides a controlled separation between
articles. A first star wheel
520 transfers articles from feed screw 510 to a turret 540. Articles are then
presented by turret 540 to
drum 100' of assembly 25' for application of labels to the articles. Upon
further rotation of turret 540,
the articles are then transferred to a second star wheel 530, and then to
conveyor 502 for transport out
of apparatus 500.
It should be appreciated that the use and configuration of feed screws, star
wheels and turrets
are in general well known in the art. It should further be appreciated that
other article transport
assemblies may be used in the alternative, e.g., various other arrangements of
feed screws, turrets
and/or star wheels, among others.
It should further be appreciated that the carrier mechanisms described herein
may be used
independently of a labeling apparatus to transfer articles. 1n the packaging
and/or bottling fields, for
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example, such mechanisms may be used to transport articles such as containers
with a controlled pitch
therebetween in various applications such as bottling machines, filling
machines, cleaning machines,
packing machines, etc. Moreover, in other fields, the carrier mechanisms may
be used in other
applications to provide controlled pitch between articles transported thereby.
Also, as discussed above,
the parameter controlled by a carrier mechanism consistent with the invention
may be another transfer
characteristic related to pitch such as velocity. This would permit, for
example, a carrier mechanism to
be used to transfer articles from a first station that outputs the articles at
a first velocity to a second
station that receives the articles at a second velocity, among other
applications. Therefore, the
invention should not be limited to any particular field or application of the
carrier mechanisms
described herein.
Fig. 13 illustrates another alternate labeling apparatus 1000 consistent with
the principles of
the invention. With the exception of the specific modifications and
enhancements discussed below,
apparatus 1000 is similar in configuration and operation to the various
designs discussed above.
Apparatus 1000 is principally used to apply labels in a continuous fashion to
a plurality of
articles 2 conveyed from an infeed mechanism 1002 to a discharge mechanism
1004 (here, both
implemented by a common conveyor 1006). Other infeed and discharge mechanisms,
appropriate for
the particular articles conveyed to and from labeling apparatus 1000 may be
used in other applications,
e.g., feed screws, belts, etc. The term "infeed", as used hereinafter, refers
to an upstream position or
direction relative to the flow of articles and labels. Likewise, the term
"discharge" refers to a
downstream position or direction relative to the flow of articles and labels.
Articles 2 are conveyed from infeed mechanism 1002 to a label application
assembly or
mechanism 1010 using an infeed carrier mechanism 1012, and then to discharge
mechanism 1004 using
a discharge carrier mechanism 1014. Infeed carrier mechanism 1012 includes a
flow starwheel 1020
and an infeed starwheel 1030. Flow starwheel 1020 includes a plurality of
teeth 1022 that define a
plurality of pockets 1024, with each pocket retaining an article 2 for
transfer from infeed mechanism
1002 to infeed starwheel 1030 along a path defined between an infeed guide
1026 and an arcuate guide
1028. As will be discussed in greater detail below, flow starwheel 1020
includes a pair of resiliently
coupled disks that minimize the clearance between a retained article and the
flow and infeed starwheels
during transfer of the article between the starwheels.
Infeed starwheel 1030 includes a plurality of teeth 1032 that define a
plurality of pockets
1034, each for retaining an article 2 for transfer along arcuate guide 1028 to
a label application station
1036 disposed opposite assembly 1010. As will be discussed in greater detail
below, flow and infeed
starwheels 1020, 1030 increase the separation between successive articles
received from infeed
mechanism 1002 to a distance suitable for applying labels provided on a label
transfer mechanism (here
label transfer or applicator drum 1038) in label application assembly 1010.
Other label transfer
mechanisms suitable for transferring a label to an article for application of
the label thereto may be used
in the alternative, including both rotary and linear-based transfer mechanisms
such as belts, movable
pads, magazines for cut labels, etc.
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Application station 1036 includes an arcuate guide 1040 against which the
articles are
compressed by applicator drum 1038 as labels are applied to the articles.
Guide 1040 includes a
resilient friction surface to impart a rolling action to the articles as the
articles pass through the label
application station such that labels are wrapped around the articles.
Discharge carrier mechanism 1014, which incorporates a discharge starwheel
1042 having a
plurality of teeth 1044 defining a plurality of pockets 1046, performs
essentially the same operation as
carrier mechanism 1012 except that mechanism 1014 operates to decelerate
articles to a linear velocity
suitable for transport by discharge mechanism 1004. By doing so, this
arrangement imparts greater
stability to discharged articles by minimizing relative movement of the
articles to the discharge
mechanism 1004. Articles are transferred by discharge starwheel 1042 along an
arcuate guide 1048
and into a gap formed between guide 1048 and a discharge guide 1050 for
discharge onto discharge
mechanism 1004.
In the illustrated embodiment, guides 1026, 1028, 1036, 1048 and 1050 are all
laterally
adjustable (e.g., through set screw arrangements, not shown) to customize the
width of the article path
I S to accommodate different diameters of articles. For labeling machines that
are used only with one type
of article, such adjustments may not be required.
Labels are supplied to applicator drum 1038 from a web supply 1060 supplying a
web 4 of
labeling material. Web supply 1060 includes a pair of supply rolls 1062, 1064,
that supply web 4 to a
measuring roller assembly 1066. Measuring roller assembly 1066 operates as a
linear feed rate sensor
using a free-wheeling roller 1068 coupled to a rotational position sensor
1070, e.g., an optical encoder.
Web 4 proceeds from assembly 1066 to a web tracking control assembly 1072
(including a roller 1073)
that is utilized to maintain lateral alignment of the web in assembly 1010.
Web 4 then proceeds to a
registration sensor station 1074 that detects the position of registration
marks disposed on the web.
Station 1074 includes a roller 1076 and a registration sensor 1078 disposed
opposite roller 1076 at a
lateral position relative to the web to detect registration marks disposed
thereon.
From registration station 1074, web 4 proceeds to the surface of applicator
drum 1038, where
an attraction mechanism (here a plurality of vacuum ports) disposed on the
outer surface of the drum
applies a controlled tension to the web. Moreover, a pair of movable cutter
assemblies 1080, 1082
disposed on drum 1038 operate to sever labels from web 4 as each assembly
1080, 1082 passes a
cutting station 1084 having a fixed knife 1086.
In some applications it may be desirable to utilize friction reduction
mechanisms in one or
more of the rollers 1068, 1073 and 1076 to minimize the amount of force
required by the attraction
mechanism on drum 1038 to draw web 4 from the supply rolls, particularly
during initial startup of the
labeling apparatus. For example, in one embodiment, it may be desirable to
couple roller 1068 to an air
turbine of conventional design, which may be used to in effect compensate for
the friction and inertia of
the other components feeding web 4 to drum 1038, thus enabling a lower vacuum
to be used on drum
1038. In other applications, however, friction reduction in the web supply
rolls may not be required.
An adhesive station assembly 1090 is disposed beyond cutting station 1084 to
apply adhesive
to leading and trailing ends of each label using an application roller 1092,
after the label has been
CA 02335935 2000-12-21
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severed from the web at cutting station 1084. As will be discussed below, a
fluid dispenser 1094 may
be used to direct a flow of fluid (e.g., pressurized air) toward the nip
formed between roller 1092 and
drum 1038, from a position upstream of the nip. Doing so reduces the
likelihood of a label following
roller 1092 after the application of adhesive thereto. Further, in some
applications, the flow of fluid
may permit a free portion of the trailing end of a label to wrap around roller
1092 prior to passing the
free portion into the nip, which improves the application of adhesive to the
trailing end, and often
reduces any overspray of adhesive onto the outer surface of drum 1038.
Moreover, by reducing the
likelihood of the label following roller 1092, often the vacuum level provided
to the outer surface of the
drum can be reduced, minimizing stretching of the web, and often improving web
tracking and cutting
as well.
After adhesive is applied to the leading and trailing edges of a label, the
label is presented to
an article 2 via rotation of applicator drum 1038, whereby rotation of
applicator drum 1038 through
label application station 1036 wraps the label around the article as the
article rolls against guide 1040.
As discussed above, apparatus 1000 incorporates a fluid dispenser to assist in
the application
of adhesive to labels, as well as unique flow and discharge starwheel designs
to assist in both the infeed
and discharge of articles to and from the apparatus. Each of these noted
components will be described
in greater detail below.
Adhesive Application With Fluid Assist
Fig. 14A illustrates applicator drum 1038 and adhesive applicator 1090 in
greater detail.
Applicator drum 1038 includes a rotatable drum body 1100 configured to rotate
about a fixed shaft
1102. Rotatable body 1100 includes an outer surface 1104 having a plurality of
vacuum ports 1106
disposed thereon and supplied with a source of negative andlor positive
pressure through a set of
distribution channels 1108.
Two sets of raised pads 1110, I 112 and 1114, 1116 are disposed on outer
surface 1104 to
receive leading and trailing edges of a label as the label passes adhesive
roller 1092 of applicator 1090
so that adhesive may be applied to the opposing edges of the labels.
Applicator roller 1092 is offset
from outer surface 1104 such a distance that label material supported on any
pad 1110-1116 will be
compressed against the roller, but material disposed between the pads will
not. Thus, adhesive is
applied only to the material supported on a pad.
The leading edges of pads I 110, 1114, and the trailing edges of pads 1112,
1116, are
respectively separated from one another around the circumference of drum 1038
at a distance that is
approximately the length of the cut labels so that, once a label is severed
from the web, the leading and
trailing ends thereof are each disposed on a pad when the label passes under
adhesive roller 1092. As a
result, adhesive is applied only to the leading and trailing ends of each
label. In the alternative, roller
1092 may be positioned, and pads 1110 - 1116 may be separated from one
another, to apply adhesive to
the leading edge of each label prior to the label being severed from the web.
Two sets of pads, pads 1110 and 1112, and pads 1114 and 1 I 16, are provided
around the
circumference of rotatable body 102, each matched with a cutter mechanism
1080, 1082. Cutter
r~~'"~.".~.',
CA 02335935 2000-12-21 w
. . .. . ... . .. . . : . ................
::. ~ :::::
-2?-
mechaaistn 1080 (which is configured is a similar manna' to cotter mechanism
1082) includes a tucker
body 1118 pivotally tnouated to giver about a shag I 120 drat extends
psttilicl to shafr 1102. A bushing
1122 formed of carbon bronze matrix operates as a bearing surface against
which shaft I 120 rotates. As
shows itt Fig. 14H, bushing 1 I22 inchzdes a bear~g staface 1123 with a
recessed portion 11Z3a foeaed
directly opposite the force vector (i,denrifed at "V") applied to rocker body
I 118. 'Ihe recess is adapud
to bear shaft I 120 at two points to n>itunrize lsocral movement of the tvcka
body on the shaft, acrd
thereby stabilize the rocker assembly. Tluough this cottfigtastion, greener
catdag gteGisioa may be
obtained than conventional bushing desiglss.
Rctutniztg to Fig. 14A, at one cad of body 1118 is disposed a cam follower
assembly 1124
including a mller 1126 rotambly mounted about an axle 1128_ Axle I 128 is
sccaued via a bolt 1130 to a
follower body 1132, and a flexible boot 1134 seals the assembly. Cam follower
asserztbly 1 I36 of cutter
atechaaism 1082 is configured s~tailarly to assembly I 124.
Knife assembly 1138 is disposed at the opposix cad of rocker body 1118 from
cam follower
assembly 1124. A knife blade 1140, having art tdge 1142, is secured to the end
of rocket body t 1 i8 via
a bolt or other securing mechanism 1144_ $dgc 1 I42 of knife blade 11 d0
projects through as opening
1146 is error surface 1104 of body 1100, itnatediately following trailing pad
1112 atotutd the
circtunfert:ace of body l I Q0.
A spring assembly 1148 including a spring 1150 extends papcndicular to shaft
1102 aced biases
tatter assembly 1080 toward ari extcaded position, with kmfc blade 1140
projecting through opeaiag
24 I 146 beyond outer surface 1104. A set screw 1152 controls the tension of
spring 1150.
Roller 1126 of care follower assembly 112a rides along a cam I I S4 disposed
oa the once surfact
of shaft 1102_ Cam I 154 is circular in cross section with the exception of a
recessed portion 1 I56.
Recessed portion 1156 stay have any aurrxber of profiles, e.g., a flaatned
proftlc as iilnstrated ~ Fig. 14A.
Recessed portion 1156 is aagulatly oriented such that roller 1126 engages the
portion when htife blade
1140 of knifr assembly 1138 is directly opposite fixed knife 1086 of cutting
station 1084, thertby extending
the kttifc blade at this position to shear a IaDel fcom the web.
To further assist in taaintaiaing lath label on the outer sutfact of drum 1038
during adhesive
application, a fluid dispenser 1094 is disposed in a position to direct a flow
of fluid toward the nip formed
becwecit adhesive roller l09Z and drum 1038. Fluid dispenser 1094 in the
il)usrraud embodiment inchtdes
3 Q an air bar 1170 mounted to a ftxcd post 1172. Air bar 1170 inchtdes a
vertical dzsmbution chartnet 1 I74
coupled to a source of pressurized fluid (e.g., cotapressed air or other gas),
and a plurality of aoates t 176
adapted to direct the pressurized fluid (represented at 1180) toward trip
1178. 1n the illustrated eatbodimeae,
air bar I 170 is separated from nip I 178 by approximately four inches (I0.16
cm , has 10 nozzles, wit4
0.04 inch ( 1.016 ttsm) diameters, and is supplied with approximately 20 ho 40
psiq f pt ssmized a her
p
3 5 separations. flow rates, directions of flow (e.g~ angk of attack relative
to the ttip), and other fluid flow
paramttcts tray be utilized is other applicxriotrs.
In operation, the >mbei material is edvaaccd by the web supply at a rate
slower than the rotational
cart of drum 1038, with the vacaum ports on the dnun providing tatsioa to
withdraw the web fiom the web
supply. Once an arnotmt of web material suitable to pmvide a desired length of
label is
~MtI~DED S~EE~,
,....:.,.:,.:.::;:~.v.::,:;- :-.:<:w;::::=
P..r~~Itt~~~8 fl9... ~~O(~. ::.
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withdrawn from the web supply, the leading edge of the web is supported on a
leading pad 1110, 1114.
At the same time, cutter mechanism 1080, 1082 passes fixed knife 1086,
severing a label from the web.
Upon further rotation of the drum, leading pad 1 I 10, 1114 passes adhesive
roller 1092 to apply a layer
of adhesive to the leading end of the label. Continued rotation of the drum
then results in the trailing
pad passing the adhesive roller to apply adhesive to the label proximate the
trailing edge. Cutting and
adhesive application of the label is then complete, and further rotation of
the drum (coordinated with
the advancement of articles) results in the label being wrapped around an
article at station 1036 (Fig.
13).
Figs. 15A and 15B generally illustrate the operation of fluid dispenser 1094
in assisting in the
application of adhesive to a label in a manner consistent with the invention.
First, as shown in Fig.
15A, when application roller 1092 is applying adhesive to a leading edge 4a of
a cut label 5, the flow of
fluid 1180 directed at nip 1178 assists in preventing leading edge 4a from
following adhesive roller
1092 after exiting the nip. As a result, greater reliability is often obtained
due to a reduced likelihood
of jamming the apparatus as a result of a label misfeed during adhesive
application. In addition, in
some applications it may be possible to lower the vacuum supplied to drum 1038
while maintaining
sutl'icient reliability, which may be advantageous due to better web tracking,
reduced stretching of the
web and better cutting performance.
In addition, as shown in Fig. 15B, when application roller 1092 is applying
adhesive to a
trailing edge 4b of label 5, the flow of fluid 1180 directed at nip 1178 may
be used to assist in urging
the trailing edge 4b to lift from trailing pad 1112 and wrap around roller
1092 before entering the nip.
In particular, due to the separation between trailing pad 1112 and knife 1140,
a portion of label 5 at
trailing edge 4b is not supported on pad 1112, and thus is left free.
By directing the free end around the roller, adhesive is applied to the very
end of the label,
which would not otherwise occur since the free end would not be supported on
pad 1112. Improved
adhesive patterns result, improving the appearance and quality of a labeled
article. Moreover, in some
applications, directing the free trailing end of the label around the roller
reduces the undesirable
overspray of adhesive from roller 1092 onto drum 1038, reducing the frequency
at which the drum must
be cleaned and improving reliability due to reduced likelihood of oversprayed
adhesive causing a label
misfeed on the drum. Furthermore, in some applications, it may be desirable to
increase the amount of
free label material at the trailing end of a label to improve the adhesive
pattern at the trailing end, e.g.,
by increasing the separation of a trailing pad from a knife and/or by
eliminating one or more rows of
vacuum ports from the trailing edge of a trailing pad.
Other fluid dispenser designs may be utilized in the alternative. For example,
other
configurations of nozzles and other types of fluid ports may be used.
Moreover, other fluid sources,
e.g., fan motors, airflow that is generated by the shape or other
configuration of the drum, etc., may also
be used. Other modifications will be apparent to one of ordinary skill in the
art.
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Article Infeed
Returning to Fig. 13, articles 2 are supplied to apparatus 1000 via an infeed
mechanism 1002.
The flow of these articles into the apparatus is controlled by a flow
starwheel 1020, illustrated in
greater detail in Figs. 16 and 17, including a plurality of teeth 1022 forming
a plurality of pockets 1024
for advancing articles into the apparatus.
Starwheel 1020 includes a rotatable hub 1200 mounted on a shaft 1202 and
secured thereto in
a keyed arrangement via a keyed member 1204 secured to the hub by fasteners
1206.
Shaft 1202 is coupled to a drive mechanism (not shown) used to drive the
starwheel in a
coordinated fashion with starwheels 1030 and 1042, as well as drum 1038,
typically through a drive
train providing a fixed relative rotation rate for each such component. For
example, shaft 1202 may be
coupled to a rotatable pulley through a universal linkage, with the pulley
coupled via a belt to the other
rotatable components in apparatus 1000. It may be desirable to provide a
clutch mechanism in the
drive for starwheel 1020 to permit the apparatus to be halted in a
predetermined rotational position.
Other drive mechanisms may also be used in the alternative.
Starwheel 1020 includes a unique engagement surface that is resiliently
coupled to the
rotatable hub to vary a rotational position of a pocket relative to the hub.
By resiliently coupling the
engagement surface to the hub, clearance between an article and either of
starwheel 1020 and infeed
starwheel 1030 (Fig. 13) can be minimized to reduce vibrations in the flow of
articles and thereby
improve the stability of the articles as they enter apparatus 1000.
Provision of a resiliently-biased engagement surface is made through a pair of
disks 1208,
1210 rotatably mounted on opposing surfaces of hub 1200. Each of disks 1208
and 1210 and hub 1022
include cooperative profiles including a plurality of teeth defining a
plurality of pockets therebetween.
As used herein, therefore, an engagement surface is defined on each pocket of
each disk 1208, 1210.
Disks 1208 and 1210 are secured to one another by a plurality of shafts 1212
(e.g., five such shafts)
retained within cooperating slots 1214 in hub 1200. One end of each slot 1214
defines a position of the
cooperating shaft 1212 (and accordingly the disks 1208 and 1210) in which each
tooth defined in the
profile of each disk aligns with one of the teeth formed in the profile of hub
1200. When each shaft
1212 is disposed at the opposite end of each slot 1214, the teeth defined in
the profiles of disks 1208,
1210 are disposed forward of the teeth defined on hub 1200 in the direction of
rotation of starwheel
1020. Disks 1208, 1210 are biased in the forward position through the use of a
sequence of springs
1216, each secured at one end to shaft 1212 and at the other end to an anchor
1218 disposed within an
annular slot 1220 in hub 1200.
It should be appreciated that other resilient members, e.g., coiled or leaf
springs, torsion
springs, etc., may be utilized to resiliently bias the disks relative to the
hub. Furthermore, it should be
appreciated that only one disk may be utilized, and in addition it is not
necessary in some applications
for hub 1200 to have a cooperating profile with each disk 1208, 1210. For
example, in other
applications it may be desirable to simply utilize a pair of concentric hubs
joined through an annular
bearing and rotationally resilient coupling mechanism, with the inner hub
mounted to the shaft and the
outer hub providing the desired starwheel profile.
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Other manners of providing a resiliently-biased engagement surface may also be
utilized in the
alternative. For example, rather than utilizing separate bodies for a hub and
an engagement surface, an
engagement surface may be resiliently coupled to a hub using a deformable
body. As shown in Fig. 21,
for example, a starwheel 1300 may include a hub 1302 having a deformable body
1304 (e.g., formed of
a resilient material such as rubber) mounted about the periphery thereof to
form an engagement surface
1306. Compression forces applied between the resilient body and infeed
starwheel 1030 deform the
resilient body to compress an article between such components.
Also, other fonms of resiliently defonmable members, e.g., inflated starwheel
spokes and the
like, may also be used to provide a resilient coupling between an engagement
surface and a hub. For
example, as shown in Fig. 22, a starwheel 1310 may include an integrally-
formed inflatable body 1312
defining an engagement surface 1314 that is integrally coupled to a hub.
In general, it will be appreciated that a wide variety of resilient
engagements, which essentially
have the effect of retarding or advancing the rotational position of an
engagement surface relative to a
rotatable hub (even when such engagements move the engagement surface in a non-
arcuate manner),
may be used in the alternative.
The operation of flow starwheel 1020 in providing articles to infeed starwheel
1030 is
illustrated in greater detail in Figs. 18A-18F. Shown in Fig. I 8A are a pair
of articles 1230, 1232
supplied to the path defined between guides 1026 and 1028 by an infeed
mechanism. Article 1230 is
illustrated as being picked up by starwheel 1020, with the article initially
disposed on the trailing
surface of a tooth on hub 1200. Absent any opposing force on starwheel 1020,
disk 1208 (and disk
1210, although such disk is not shown in Figs 6A-6F) is biased to a forward
position. As shown in Fig.
18B, further rotation of starwheels 1020, 1030 results in the leading edge of
a tooth on disk 1208
engaging article 1230, driving the article forward but at the same time
overcoming the resilient bias of
the starwheel and rotating disk 1208 toward a position in alignment with hub
1200. Next, as shown in
Fig. 18C, further rotation of starwheels 1020, 1030 brings article 1230 into
contact with the outer
surface 1031 of infeed starwheel 1030, and with the disk 1208 in a rearmost
rotational position in
alignment with hub 1200. Next, as shown in Fig. 18D, further rotation of
starwheels 1020 and 1030
begins to draw article 1230 into pocket 1034 defined on outer surface 1031 of
infeed starwheel 1030.
However, as the article recesses into the pocket, the resilient bias of disk
1208 rotates the disk forward
to maintain contact between article 1230 and disk 1208 as the transfer of the
article from flow starwheel
1020 to infeed starwheel 1030 occurs. As a result, any gaps between the
article and the respective outer
surfaces of starwheels 1020 and 1030 are minimized.
Upon further rotation (Fig. 18E), article 1230 becomes seated in pocket 1034,
with disk 1208
of starwheel 1020 positioned at its forward-most position relative to hub
1200. In addition, the next
article in sequence, article 1232, is shown engaging the next pocket of
starwheel 1020. Article I230,
however, is still compressed to an extent between disk 1208 and starwheel
1030. Fig. 18F next
illustrates the release of article 1230 from starwheel 1020, with the article
securely retained within in
pocket 1034 of starwheel 1030. Article 1232 is then in position for transfer
to the next pocket in
sequence for starwheel 1030.
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Through maintaining compression of an article between starwheels 1020 and
1030, vibrations
in the articles are minimized, and as a result, the stability of the articles
feeding into the apparatus is
improved. It should be appreciated that the use of a resiliently-biased
engagement surface as described
herein may be utilized on other starwheels consistent with the invention,
e.g., in any application in
which it is desirable to transfer an article from a starwheel to another
transfer mechanism such as
another starwheel or the like. Other modifications will also be apparent to
one of ordinary skill in the
art.
article Discharge
Returning to Fig. 13, once an article is collected by infeed starwheel 1030,
the article is
transported along guide 1028 to a gap disposed between an arcuate guide 1040
and the outer surface of
drum 1038, whereby the article is rolled about a rolling axis (typically the
longitudinal axis of an article
taken through the center point of the circular cross-section of the article)
and a label is wrapped around
the article. Once at least a portion of a label is wrapped around an article,
the article is fed from the gap
between drum 1038 and guide 1040 by a discharge carrier mechanism 1014
including a discharge
starwheel 1042 with a plurality of teeth 1044 defining a plurality of pockets
1046 therebetween.
Figs. 19A-19D illustrate the configuration and operation of discharge
starwheel 1042 in
greater detail, with a plurality of articles 1240, 1242, 1244 and 1246
illustrated at various points along
the guide 1048.
Each pocket 1046 of discharge starwheel 1042 is defined by a series of arcs
between adjacent
teeth 1044. In the illustrated embodiment, the width of each pocket (defined
by the separation between
adjacent teeth) is greater than the diameter of each article such that the
precision required to engage an
article within a pocket is reduced. Furthermore, in the illustrated
embodiment, each pocket is defined
by first, second and third sections 1250, 1254 and 1252, with the first and
second sections 1250, 1252
defined by leading and trailing edges of adjacent teeth, and having a radius
of curvature that is less than
that of the intermediate third section 1254. Section 1254, providing an
engagement surface initially
contacting an article, is provided with a relatively larger radius of
curvature to minimize the coefficient
of friction between the pocket and the article during initial contact with the
article. Section 1250,
however, has a lower radius of curvature to provide a relatively higher
coefficient of friction with the
article once the article is engaged with section 1250. Providing a higher
coefficient of friction assists in
canceling the spin induced on the article by the label application process.
The transition from section
. 1254 to section 1250 is gradual, however, so that the coefficient of
friction increases as the article
slides back in pocket 1046, and a gradual deceleration of the rotational
velocity of the article is
obtained.
As shown, for example in Fig. 19A, article 1246 initially contacts a pocket of
starwheel 1042
between adjacent teeth 1044. Then, as shown in Fig. 19B, the article 1246 is
allowed to slide back into
engagement with the trailing tooth 1044, with the rotation thereof canceled
via the coefficient of friction
with the section 1250 of the pocket.
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Retutrting again ro Fig. 19A, iht configuration of stamheel 1042 is also
specifically designed
to stabilize the discharge of articles from guide 1048 onto the discharge
mechanism (here conveyor
1004 of Fig. 13). Each tooth 1044 of starwheel 1042 is configured to impart a
drcressiag linear
velocity to each article as it is discharged along guide 1050 to the conveyor.
The rotation rate of
starwheel 1042 is selected to provide a tangential velocity of articles
transferred by starwheel 1042
that is initially greater than the linear velocity of the conveyor. However,
by conveying the articles
along a linear portion of guide 1050, and by providing a decreasing linear
velocity through
engagement with each tooth 1044, the linear velocity of the articles is
decelerated below that of the
conveyor, thereby permitting the conveyor to transport the articles away from
the starivheel octet the
linear velocity thereof falls below that of the eonveyor_
As illustrated, for caamplc, by article 1242, the article is fully seated
within a pocket of
starvs~heel 1042 as the article engages arcuate guide 1050. Next, as shown in
Fig. 19B, as the article is
advanced by starwheel 1042, the linear velocity of the article along the
direction of the conveyor
decreases as the article is conveyed by the tip of the tooth 1044 against
which the article rests_ As
shown is Fig. 19C, further rotation of stasvrheel 1042 results in a further
decrease in velocity for article
1242, until the coa~eyor picks,up the article and carries away from stacwhc,-
cl 1042, as shown in
Fig. 19D_
Fig. 20 illustrates in another way the linear velocity imparted to an article
transported by
stanvheel 1042 st equal time intervals during th.e rotation of starwhccl 1D42.
The position of the
starwheel and the container 1242 is illustrated at six points of time: tp-~f
with the linear movement of the
article dozing each time interval th~betwcen denoted as d~ df. The rata of
advancement of the
conveyor during the last two time intervals is illustrated at c, and cJ (it
being understood that the
conveyor is advancing at the setae rate dtuiag the earlier time intervals as
well). It can be see,-n that
from time to to time t" the article is advanced at a linear rate that exceeds
that of the conveyor.
2~ However, once the linear rate falls below that of the conveyor at time t"
the article is advanced at the
Tare of the conveyor, and subsequently carried away from the discharge
starwheel.
It Should be appreciated Cbat other starwheel profiles may be utilized in
discharge statwhcel
1042 consistent with the invention.
Furthermore, it will also be appreciated by one skiDed in the art that the
various enhancements
to the herein described label application assemblies and carrier mechanisms
may be utilized
independently of one another in other applications.
AMENDED SHEET
