Note: Descriptions are shown in the official language in which they were submitted.
1 155~31
FIELD OF THE INVENTION
This invention relates to an apparatus and method
for precisely locating and aligning a flange of a container
and a precut lid of a series of interconnected lids, such
that after the heat sealing operation, the body portion of
the lid does not overhang the flange of the container.
B~CKGROUND OF THE INVEN'rION
In recent years, the popularity of individually
portioned containers for food products and particularly,
dairy products, has rapidly increased and the need to package
these products in a suitable manner such that they be served
to customer, has been realized by the industry. However, to
make these products economically viable, production rates
must be fairly high. To achieve these production rates the
prior art packaging machines have been designed such that
the precise location of the container and a lid is not
necessary and tolerance variations in both the lid and con-
tainer do not appreciably affect the seal. One of the most
popular methods of avoiding problems caused by tolerance
variations is to provide an oversized lid such that the
precise location of the lid relative to the flange is not
necessary and the lid only need be generally located above
a flanged container for a proper heat seal to result.
One such method is shown in United States Patent
3,838,550 which issued to Mueller, October 1st, 1974 where
an oversized heat sealable lid is applied to each container
and the resulting overhanging lid is pressed down along
the sides of the container. With this method the precise
location of a precut lid relative to a container is not
required, however, the resulting product even with the overhang-
ing lid portion pressed downward has the appearance of poor
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1 workmanship. This problem is further compounded by damage
during shipment where the overhanging portion of the lid
becomes tattered.
Although these methods ensure a good heat seal
between the lid and the container, the resulting product
has the appearance of being produced by a cheap process and
if the overhanging portion of the lid becomes crimped or
torn it leads to the appearance of shoddy workmanship and
the suggestion that the product has been tampered with.
Therefore, it is desirable to produce a product where the
precut lid is of sufficient area to cover the container and
align the lid for heat sealing, such that the lid does not
overhang the flange after it has been sealed in place. The
only exception to this being the tab portion of the lid which
projects outwardly from the flange, such that the lid may
be removed.
In some applications, a continuous sheet has been
applied over nested containers and a dye cutting operation
is used to cut out the sealed lid from the sheet material and
in some circumstances this cuttlng operation also dye cuts
the container flange. Although this system provides a lid
which is precisely located above a container flange the
economy and convenience of precut and preprinted lids is
not realized.
The present invention overcomes the disadvantages
of the prior art machines which have used preprinted and
precut labels while providing the more desirable character-
istics of containers sealed with a continuous sheet material
and dye cut after the heat sealing operation.
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1~55~31
SUMMARY OF THE INVENTION
The present invention provides a method for
accurately positioning a container and a lid of a series
of precut lids for sealing the lid to the container where
each lid has a body portion corresponding to the area
defined by such container flange and a tab portion for
removing a sealed lid, such that the body portion of a
heat sealed lid is aligned with and essentially with the
periphery of such container flange. The method comprises
the steps of;
a) dispensing a container into a conveyor bed adapted
to receive such container and accurately locate
the flange of such container;
b) advancing such containers through a number of work
stations;
c) advancing the series of interconnected lids with
the movement of the conveyor in a manner whereby
the first lid of the series of interconnected lids
i9 free to interact with the adapted conveyor bed;
d) generally positioning a lid with respect to an
associated container located in the conveyor;
e) aligning the positioned lid with the flange of the
associated container by engaging at least a number
of point~ about the periphery of the lid ;
f) heat sealing the aligned lid to the associated
container;
whereby the body of a heat sealed lid is locatsd
essentially within the periphery of the associated
container flange.
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~15543~
The apparatus according to the present invention for
accurately positioning and aligning a lid of a series of
interconnected lids above a container flange in
preparation for sealing such a lid to a container each
lid having a body portion corresponding to the area
defined by such container flange and a tab portion for
removing A heat sealed lid from a container comprises a
conveyor bed for conveying containers and having locating
means for spacing said containers in said conveyor bed,
means for dispensing a container into said conveyor,
drive means for indexing the conveyor belt and halting
said conveyor at fixed intervals corresponding to such
container spacing; means for positioning a lid of such
series of lids over conveyed containers preparatory to
heat sealing a lid to a container flange in a manner to
allow the end lid of the series of interconnected lids to
freely interact with said conveyor beds, wherein said
conveyor bed includes upwardly opening guide means for
first loosely receiving a container and subsequently
engaging container flange and accurately position the
flange relative to said conveyor bed, said guide means
further engaging at least a portion of the periphery of a
lid of such series of interconnected lids to advance such
series and position the body portion of a lid directly
above the flange of a nested container and within the
periphery thereof, and heat sealing means for sealing
such positioned lid and container.
3 ~55431
PRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are shown in
the drawings, wherein:
Figure 1 is a side elevation of the container
filling and sealing apparatus;
Figure 2 is a partial perspective view of the
apparatus showing the conveyor bed and heat sealing
station with the clamping pads and heat sealing head
partially removed for better observation;
Figure 3 is a side elevation of the conveyor bed and
clamping station;
Figure 4 is a top view of the heat sealing station;
Figure 5 is a partial view of two conveyor plates
and associated guide rail;
Figure 6 is a perspective of the lid advance
mechanism;
Figure 7 is a perspective view of the clamping pads;
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1 Figure 8 is a perspective view of a container with
a sealed lid;
Figure 9 is a top view with a lid partially removed
from a container and
Figure 10 shows a portion of a series of interconnected
lids and the points of severance for separating the lids.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus shown in Figure 1 is designed to fill
individual portion creamer containers which have gained wide
acceptance throughout both the European and the North American
markets. The apparatus has a container supply chute 2, which
receives a stack of nested containers and drops the containers
at the appropriate time such that a container is received
within the conveyor bed 10. The product filling station is
generally shown as 4 and is synchronized with the movement
of the conveyor bed to fill a container located beneath the
spout 5. The lid supply system 6 is adapted to receive a roll
of interconnected preprinted and precut container lids with
a series of lids being fed past the roller 34 and onto the
lid drive drum 32. The drum 32 is constantly driven, in
contrast to the intermittent movement of the conveyor bed, such
that the series of lids has a curved downward portion 30 which,
provides some compensation as the series of lids engage
alignment means provided in the conveyor bed. The series
of lids are generally advanced by the drive drum 32
and the conveyor bed is provided with alignment means for
positioning the series of lids directly above containers.
Thus the roller 34 and the drive drum 32 ~form the lid drive
mechanism ~.
Both the lid.severance station 12 and the heat seal
1~5431
1 station 14 are driven in timed relationship with the conveyor
bed movement and will be more fully described in relation to
the remaining figures.
To assist in positively locating the series of inter-
connecting lids, proximate the upper surface of the conveyor
bed, guide member 18 is provided. A container unloading system
is generally shown as position 16 in Figure 1.
The clamping pads support block 62 is shown in
Figure 2 with individual clamping pads 64 journalled within
the support block and having a positioning rod 66 adapted
to maintain the orientation of the clamping pads. These
clamping pads are spring loaded and adapted to move relative
to the support block when the drive means 60 lowers the support
block relative to the conveyor bed, firmly positioning
two adjacent lids and allowing the severance of the inter-
connecting tab between the lids. The clamping pads are
designed to engage only a portion of a lid as the guide
rails 17 extend beneath the lid severance station and con-
tact a portion of the lid urging it downwardly into engagement
~0 with the lugs 122 and 124 which position and advance the
series of interconnected lids with the conveyor movement. Due
to the particular arrangement of having the guide rail 17
extend beneath the lid severance station, the clamping pads
64 must maintain their orientation relative to the conveyor bed
and thus the rod 66 positively maintains this position and
the brackets 68 assures the rod does not accidently disengage
the clamping pads. During compression of the clamping pads,
the rod merely moves upwardly with the clamping pads and
the brackets 68 are of sufficient height such that the rod
does not rise above the brackets.
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1155~31
1 The heat sealing unit 40 has a number of individual
heat sealing pads 42 spring loaded to the base of the heat
sealing unit and the drive mechanism 44 secures the heat
sealing unit and synchronizes it with the movement conveyor
bed. The heat sealing unit is secured to the drive 44 by
the yoke and axle arrangement 46 and 48 in combination with
the lock pins 50 and apertures 52.
Turning to Figures 3 and 4, the lid severance and
heat sealing station are shown in more full detail. The
series of interconnected lids 100 curve downwardly towards
the conveyor bed immediately upstream of the clamping station
such that only approximately 3 lids of the series engage the
conveyor bed prior to severance of a lid ~rom this series.
The lid 101 immediately upstream of the severance station
as shown in Figure 3, is engaging the forward alignment lug
122a of that particular conveyor plate but due to the series
of lids curving upward toward drive drum 32 the trailing
periphery of the lid has not yet engaged alignment lug 124a.
Thus, as shown in Figure 3, only two lids of the series of
~0 interconnected lids fully engage or lie within conveyor plates
and the third lid, has not fully engaged a conveyor plate.
This aspect of controlling the number of lids engaging the
conveyor is important because tolerance variations in the
exact spacing between lids of the series of interconnecting
lids will vary within manufacturing tolerances and the
cumulative variation of these tolerances increases with the
number of conveyor plates engaged.
The conveyor apparatus as shown in Figure 3 is position-
ed such that the conveyor bed is now stationary and the clamp-
ing pads 64 and heat sealing head 40 will move downwardly
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1 155431
1 to free a lid from the series of interconnected lids and
heat seal a lid to a container~ After sufficient movement
of the clamping pads 64 the knife 63 contacts the intercon-
necting tab portion of a lid and severs it freeing a lid
from a series of interconnected lids. The guide rails 17
assure the series of interconnected lids remain in engage-
ment with a portion of the conveyor bed and also assure the
freed lid remains in proper location with the alignment lugs
in preparation for the heat sealing operation. These guide
rails 17 are supported by bar member 19 which traverses
across the width of the conveyor and, is secured to the sup-
porting sidewalls of the machine.
Several plates of the conveyor bed are shown in
Figure 5 in relation to the guide rails 17. The conveyor plate
120b has been cut away through a nested container, showing
the relationship between the alignment lugs 122 and 124,
flange 200 o~ a nested container and aperture 121 provided
in the conveyor plate. Each of the alignment lugs has been
provided with a curved portion 125 corresponding to a portion
of the outer periphery of the flange 200. At the upper surface
of the conveyor plate, the curved portion 125 is adapted to
essentially contact the outer periphery of the flange 200
with both sets of alignment lugs 122 and 124. The curved
portion 125 tapers upward and outwardly from the upper sur-
face of the conveyor plate to provide a guide means for
initially, loosely receiving the container flange 200 and
subsequently aligning this flange in relationship to the
conveyor plate which has been recessed to receive the flange.
As can be seen, the aperture 121 provided in the plate is
oversized relative to the body of the nested container
1 1554~1
1 such that the exact position of the container in the conveyor
bed is determined by the inter engagement of the container
flange and the alignment lugs.
During the t~rmo-forming process of these con-tainers,
wide tolerance variations are expected between the center
axis of the container and the center axis of the container
flange. Although these axis should be the same, variations
do occur however, the outer periphery of the flange is relatively
constant and only varies within much smaller tolerances as it
is dye cut. For example, tolerance variations in the size of
lids and the diameter of creamer containers may be up to
approximately four thousandths and three thousandths of an
inch respectively whereas variations in the position of
the center axis of the container may be as much as 20 thousandths
of an inch. Thus, by aligning the container by contacting
the flange and having these same alignment lugs positon the
series of interconnected lids; accurate positioning of the
lid, relative to the container flange can be achieved and the
wide tolerance variation of the position of the center axis of
~0 the container, do not effect the sealing operation of the
apparatus. Therefore, the need for oversized lids or more
strict control over existing manufacturing tolerances of
both lids and containers is not required with the present
apparatus while still allowing precise location of the lid
relative to the container flange such that the body portion
102 of the lid is directly above the container flange and
only the tab portlon 104 projects beyond the container flange.
The guide rail 17 shown in Figure 5 extends between
alignment lugs of adjacent container apertures 121c and is of
sufficient width to contact a portion of both adjacent lids.
54~ 1
1 Although this rail is in close proximity to the conveyor
bed, it is not in contact with the bed and actually allows the
series of interconnected lids to move along a portion of the
tapered surface 125, but not above the alignment lugs thus,
providing some compensation for tolerances. During the
clamping operation and the heat sealing operation, a lid
in contact with the alignment lug is forced downwardly and
the tapered section contacts the periphery of the lid and
positions it relative to the container flange. Therefore,
the precise location of the lid is assisted due to the clamp-
ing action of the clamping pad 64 and during the downward
movement of the heat sealing head 40, prior to bottoming
out against the conveyor bed.
The present system achieves the result of precisely
locating the lid above a container flange by allowing for a
small degree of tolerance variations due to the tapered
alignment lugs 124 and 122 as well as the curved portion 100
of the series of interconnected lids which is achieved through~
the operation of the drive drum 32. This drive drum is shown
in more detail in Figure 6 and is provided with projecting
lugs 37 for engaging the series of interconnected lids. Be-
cause the drive drum 32 is constantly driven and the conveyor
is intermittently advanced, the curved portion 100 is always
varying to a certain extent. However the arrangement is
such that the series of lids may be positioned on drum 32
such that free end portion of the lids always curve down-
ward to the conveyor bed in a manner such that they readily
engage and move with advancement of the conveyor bed. Thus
drum 32 isolates -the free end portion of the series of lids
from velocity and tensions, fluctuations between drum 32 and
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1155~31
1 and the supply roll 36. It is preferred to have the drum
32 constantly driven to avoid problems such as tearing of the
lids between the drum and the supply roll 36 which may occur
should the drum be indexed with movement of the conveyor bed.
As can be seen in Figure 7 the clamping pads 64 are
not circular so they do not contact the guide rails 17 during
' the clamping operation.
Figure 8 and 9 shows containers heat sea'ed by this
process and the body portion 102 of the lid is located within
the periphery of the flange. The tab portion 104 of the lid
projects from the lid and assists in removal of the lid by
the end user. By cutting the lids along the severance lines
105, shown in Figure 10 the overall appearance of the finished
product is enhanced as only one tab portion is provided and
is preferred according to the invention.
The present invention utilizes precut, preprinted
interconnected lids in combination with containers mass
produced by thermoforming techniques while still providing a
system in which the lid essentially corresponds to the
~0 periphery of the flange of the containers and is heat sealed
thereto. Such a system results in cost savings due to the
reduced size of container lids and provides a product that
is less vulnerable to lid damage. Thus the final product
does not appear tattered when served for consumption and
the consumer is not as likely to immediately question the
quality of the product.
Prior art systems have provided wide tolerances
allowances in both the apparatus for handling this type of
packaging operation as well as in the individual components
but result in a somewhat shabby looking finished product.
~L55~3~
1 The present system is capable of high production output as
well as obtaining the desirable characteristics of a more
finished final product.
Although various embodiments of the invention have
been described herein in detail, it will be understood by
those skilled in the art that variations may be made thereto
without departing ~rom the spirit of the invention or the
scope of the appended claims.
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