Note: Descriptions are shown in the official language in which they were submitted.
CA 02558678 1995-06-08
AUTOMATED APPARATUS AND METHOD
FOR CONSOLIDATING PRODUCTS FOR PACKAGING
This application is a divisional application of
Canadian Patent Application Serial No. 2,151,343 filed
June 8, 1995 entitled "Automated apparatus and method
for consolidating Products for Packaging".
1. Field of the Invenaifln
The present invention relates generally to the
field of manufacturing ophthalmic lenses, especially
molded, hydrophilic contact lenses, and more
specifically to an automated apparatus for consolidating
contact lenses for packaging after inspection thereof.
2. Description of the Prior Art
The molding of hydrophilic contact lenses is
disclosed in U.S. Patent No. 4,495,313 to-Larsen; U.S.
Patent No. 4,640,489 to Larsen, et al.; U.S. Patent No.
4,680,336 to Larsen et al.; U.S. Patent No. 4,889,664 to
Larsen et al.; and U.S. Patent No. 5,039,459 to Larsen
et al., all of which are assigned to the assignee of the
present invention.'
These prior art references disclose a contact lens
production process wherein each lens is formed by
sandwiching monomer or monomer mixture between a front
curve (lower) mold section and back curve (upper) mold
section, carried in a two by four mold array. The
monomer is polymerized, thus forming a lens which is
then removed from the mold sections and further treated
in a hydration bath and packaged for consumer use.
U.S. Patent Nos. 5,080,839 and 5,094,609 disclose
respectively a process for hydrating contact lenses and
a chamber for hydrating contacts lenses formed with a
monomer or monomer mixtures disclosed in the forgoing
patents. The process disclosed in these patents
significantly reduce the thruput time by hydrating the
lens and releasing the lens from the mold cavity with
CA 02558678 1995-06-08
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deionized water and a small amount of surfactant without
1 any salts, so that the time consuming ionic
neutralization of the polymer from which the lens blank
is made does not occur during the hydration process.
When deionized water is used, the final step of the
process, is to introduce buffered saline solution into
the final package with the lens and then seal the lens
Within the package so that the final lens equilibrium
(ionic neutralization, final hydration and final lens
dimensioning) is accomplished in the package at room
temperature or during sterilization.
U.S. Patent No. 4,961,820, also assigned to the
assignee of the present invention, discloses a final
package for a contact lens, wherein the package is
formed from a transparent plastic material such as
polypropylene and a foil laminate that is heat sealed
thereto.
While U.S. Patents 5,080,839 and 5,094,609
contemplate that the entire hydration process and
transfer to final packaging may take place in a fully
automated fashion, and while the chamber and process
described in the foregoing patents enabled automated
handling of the lens during hydration, suitable
automated equipment to inspect and handle the lenses at
high production rates and implement the methods thereof
in a,fully automated apparatus was not readily available
or taught by the prior art.
SUMMARY OF THE INVENTION
Recent developments in the inspection of contact
lenses produced in accordance with the foregoing methods
has enabled automated lens inspection, as taught in
EP Patent No. 604179 entitled "Lens Inspection Method and
Apparatus", assigned to the assignee of the present
CA 02558678 1995-06-08
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invention. Further, recent developments in the hydration
and automated handling of wet contact lenses, as taught
1 in U.S. Patent No. 5,476,111 "Automated Method and
Apparatus for Hydrating Soft Contact Lenses", also
assigned to the assignee in'tfie present invention,
has enabled automatic robotic handling of
lenses during hydration, and prior to the inspection
thereof by the automated lens inspection system.
The removal of lenses, that are out of product
specification, from a serial product stream of contact
lenses generates random variations in the product flow
which must be consolidated prior to packaging.
The present invention therefor provides an
automated apparatus for consolidating serial product
flow wherein the product flow includes random variations
in the flow. The present invention provides a
consolidation buffer for receiving the serial products
from the production line, and then consolidating random
variations in the product flow. The automated robotic
handling means -.then selects a --predetermined -number and -
arrangement of product units and transports that number
and arrangement to a subsequent packaging station for
packaging, sterilization, and final shipment.
It is further an object of the present invention to
provide a robotic transfer means for receiving serial
product flow, and selectively ejecting individual
product units in response to data signals from the
automated lens inspection system.
It is further awobject of the present invention to
provide a consolidation buffer between two serial
0 production operations, wherein the number and
3 arrangement of product varies between input and output.
The present invention enables use of a first x,y array
of product units merging from a serial production line,
and consolidating those product units into a second x,y
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array of units which corresponds to an array used in
1 second production operation relating to the product.
It is further an object of the present invention to
provide a programmable logic controller which maintains
a status count for each of the individual products in
the consolidation buffers of the present invention,
including a count for each random addition of product,
and a separate count for each selection and transport of
product from the buffers to the final packaging station.
It is another object of the present invention to
l0 provide a method and apparatus for the high speed
robotic handling of discrete final packages of product
having a soft contact lens carried therein. This
robotic handling enables selective ejection or rejection
of specific lenses, even when carried in a predetermined
X,Y array, when one or more of said lenses have been
flagged as flawed or out of spec by the automated lens
' inspection system.,
It is another object of the present invention to
provide an automated control means for sequencing and - ..._.
coordinating each of the robotic assemblies used in the
transfer of lenses from the automated lens inspection
system to final packaging.
While the invention is described with particular
reference to molded contact lenses wherein the lens has
been molded between a first and second mold half, as
2
5 described in U.S. Patent No. 5,804,107 "Consolidated
Contact Lens Molding", it is understood the present
consolidation apparatus is equally suitable for the
consolidation of lenses formed by lathe cutting wherein
0 the hydrogel is maintained at a dry state while the
3
desired optical surfaces are cut and polished. Further,
the apparatus of the present invention may also be used
in consolidating spin cast lenses which subject a liquid
CA 02558678 1995-06-08
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monomer to centrifugal force in a mold which has the
1 same shape as the desired optical surfaces of the lens.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing objects and advantages of the present
invention for an automated apparatus and method for
consolidating products for packaging may be more readily
understood by one skilled in the art with reference
being had to the following detailed description of the
preferred embodiments, taken in conjunction with the
accompanying drawings, wherein like elements are
designated by identical reference numerals throughout
the several views, and in which:
Figure 1 is a diagrammatic illustration of plural
robotic handling means, and a consolidation buffer for
removing random variations in product flow.
Figure 2 is an elevation view of the automated lens
inspection system and the stations utilized in the
initial handling of the lenses prior to the automated
lens inspection.
Figure 3 is a plan view of the apparatus
illustrated in Figure 2.
Figure 4 is an elevation view of the consolidation
buffer of the present invention, and the packaging
apparatus to which the consolidated product flow is
transferred.
Figure 5 is a plan view of the apparatus
illustrated in Figure 4 illustrating both a
consolidation buffer and a packaging buffer arranged
immediately prior to the packaging apparatus.
Figure 6 is an isometric view of a contact lens
carrier which serves as both an inspection carrier, and
a portion of the final contact lens package.
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Figure 7 is an isometric view of an inspection
1 carrier used to transport a plurality of the contact
lens carriers illustrated in Figure 6 through the
automated lens inspection system.
Figure 8 is an elevation'view of the vacuum rail
consolidation buffer of the present invention.
Figure 9 is a cross-sectional view of the apparatus
illustrated in Figure 8.
Figure 10 is an enlarged plan view of the drive
mechanism utilized in the consolidation buffer of Figure
8'
Figure 11 is an elevation view of an index
registration device used to align the consolidated
product flow prior to transfer to the packaging station.
Figure 12 is a diagrammatic illustration of on
individuated robotic handling device transporting
contact lens carriers to the vacuum rail consolidation
buffer of the present invention.
DETAILED DESCRIPTION-OF THE PREFERRED EMBODIMENTS
Figure 1 is a diagrammatic illustration of the
automated apparatus of the present invention used to
consolidate serial product flow when the serial product
flow has random variations therein. While prefigured 2
X 8, 2 X 5 and 4 X 8 arrays are used in the description
of the present invention, it is understood that a
variety of arrays and configurations may be used in the
practice of the invention described herein.
As illustrated in Figure 1, an inspection pallet 10
carrying sixteen product articles 20, arranged in a
2 X 8 array 20(a) is transported in the direction of
arrow A from an automated inspection system that has
separately reviewed each of the products 20 according to
a predefined product criteria. Pallet 10 travels on a
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conveyor 12(b) through each of the three positions
1 10(a),(b) and (c) illustrated in Figure 1. After the
products have been removed from the inspection pallet
10, as indicated in 10(c), the empty inspection pallets
are returned via return conveyor 13 to be refilled with
product.
A robotic handling device 200 is positioned
adjacent conveyors 1Z, 13 and has mounted thereon a
2 X 8 vacuum array 202 having sixteen independently
actuable vacuum gripping means mounted thereon. Pallet
10(b) is conveyed along conveyor 12 to a predetermined
product pick point, as illustrated in Figure 1 and the 2
X 8 array 202 is positioned thereabove to remove each of
the sixteen products from the inspection carrier 10(b).
As illustrated in Figure 1, products 20(b),(c) and_(d)
have been marked with an "X" to diagrammatically
illustrate the removal of flawed or out spec products.
In the practice of the present invention, a programmable
logic controller is used to control the various elements
of the present invention and receives a datablock from
the automated inspection system having a flag set for
each of the products 20(b), (c) and (d) that are flawed
or out of spec.
After the products 20 have been removed from the
inspection carrier 10(b), the robotic transfer device
200 positions the 2 X 8 array over conveyor belt 14 and
selectively discharges the products 20(b), (c) and (d).
Those products are then removed by conveyor 14 for
subsequent destruction or recycling.
The robotic device 200 then places the remaining
products on a vacuum consolidation buffer 230 as
indicated at 20(d). The product array as deposited at
20.(d) includes gaps or random variations in the product
flow resulting from the removal of the out of spec
products 20(b), (c) and (d) from the serial product
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flow. The vacuum consolidation buffer 230 includes a
1 pair of pneumatic product followers 232,234 which are
used to consolidate the product group 20(d) with product
group 20(e~. Each of the pneumatic followers 232,234 is
independently advanced in the~direction of arrow C until
the product stream is consolidated. As product 20(f)
encounters product 20(g), the entire stream of product
driven by product follower 232 will advance and trigger
an optical sensor 236, which generates a control signal
for the programmable logic controller to de-energize
product follower 232 and return the follower to the
initial start position. Likewise, optical sensor 238
generates a similar return signal for product follower
234 when the second product stream has been
consolidated. After consolidation of the product, a
separate indexing mechanism 240 returns the entire
product stream in the direction of arrow D to a
predetermined registration point for subsequent robotic
handling. In the present invention, the consolidation
buffer 230 includes a-pair of vacuum rails which lightly
grip the product to permit sliding movement of the
product along the rails in response to product followers
232,234, but which will prevent "shingling" of the
product during consolidation.
A package feed robotic handling device 300 is
positioned between the consolidation buffer 230 and a
packaging station 400, and is equipped with an array 302
which contains ten vacuum gripping means arranged in a
2 X 5 matrix. The 2 X 5 array 302 is first positioned
over product group 20(f1 and the vacuum gripping means
is actuated to withdraw the first ten products from the
vacuum consolidation rail 230. The packaging robotic
handling device 300 then positions the 2 X 5 array and
product group 20(f) over position 1 on the packaging
indexing table 400, and drops the array of products onto
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support pallet 410 mounted on the packaging indexing
1 table 400. For the purposes of illustrating the
operation of the invention, only a single support pallet
410 is illustrated on the packaging indexing table 400,
although it is understood that'in actual practice eight
such support pallets are provided, one for each index
position. The ten product units 20(g), carried by
support pallet 410 are then indexed to position 2 for
product verification, and to position 3 for subsequent
product packaging operations.
During packaging, the packaging index table 400
rotates support pallets 410 from position to position to
enable the products to undergo subsequent packaging
steps. In the event there is a malfunction or delay in
the operation of the packaging indexing table 400, the
incoming product arriving on consolidation buffer 230 is
temporarily stored in a buffer area 308 which has a
plurality of buffer pallets 310 positioned therein.
When the packaging index table 400 resumes operation,
the package robotic handling device 300 will then
transfer products in the 2 X 5 arrays from the buffer
pallets 310 to the support pallets 410 on a first-in,
first-out basis.
If the product being handled is time sensitive, the
programmable logic controller can generate a time stamp
to be placed with each product array as it is
transferred from any given processing station to any
subsequent processing station. Thus, a time stamp may
be placed on the product when inspected, or when
transferred to the buffer area 308. If the product is
transferred to buffer 308, the X,Y coordinates of the
array are also stored with the time stamp. If the time
sensitive allotment expires before packaging index table
400 has resumed operation, the packaging robotic
handling device 300 will then discard expired time
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sensitive product, and will transfer only product
1 meeting the time sensitive criteria to the support
pallet 410. Likewise, if a problem in the production
line results in an inordinate number of products being
rejected, so that less than five products are available
on either consolidation string 230(a),(b) at position
20(e) then the robotic handling device 200 will transfer
product as necessary to balance product streams on both
sides of the packaging consolidation buffer 230, and
thereby enable removal of product as a 2 X 5 product
array.
POST HYDRATION PROCESSING
The present invention was designed for and is
particularly adapted for use in the post hydration
processing section of an automated contact lens
production facility. Contact lenses molded in an
automated production line, such as that described in
issued U.S. Patent No. 5,804,107 entitled "Consolidated
Contact Lens Molding", hydrated in a hydration system as
described in EP Patent No. 453231 entitled "System for
Handling Contact Lenses During Hydration", and
automatically inspected as described in EP Patent No.
604179 entitled "Lens Inspection Method and Apparatus"
are particularly well suited for consolidation and
packaging by the present invention.
The present invention envisions a multi-purpose
disposable lens package carrier which transports a
contact lens during inspection thereof, and serves as a
portion of the final packaging after inspection.
Package carrier 20 is illustrated in Figure 6 and is
formed from injection molded or thermal formed plastic
sheet material, such as polypropylene and includes a
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planar essentially rectangularly shaped base member 34
1 having an angularly depending wall portion 38 at one end
.. thereof forming a first flange member and a pair of
registration flanges 33(a),33(b), one of which is
visible in Figure 6, at the other end thereof which are
used to align the package carrier for robotic handling.
Registration notches 31(a),(b) are provided on either
side of the base 34 to cooperate with registration pins
on various support pallets used in the processing and
. packaging operations to register the package carrier and
lens for further handling or treatment. Offset from the
center of the package is a cavity 36 integrally formed
therein which is of an essentially semi-spherical
configuration, generally in conformance with a
curvilinear shape of a contact lens (not shown) which is
adapted to be stored therein in a sealed condition~while
immersed in a suitable sterile aqueous solution in a
manner similar to that described in U.S. Patent No.
4,691,820 to Martinez; which is assigned to the assignee
of the present invention, the disclosure of which being
incorporated herein by reference thereto. The height
"h" of flange member 38 depending from the planar base
member 34 is complimentary to the height or depth of
cavity 36, and provides for self alignment of the
package carrier in cooperation with depending flanges
33(a},(b} on specially configured pallet carriers, as
will hereinafter be described. Depending flange 38 is
also used in the final packaging of the product in
cooperation with a plurality of generally "chevron-
shaped" ridges 32, which will assist the end user in
gripping the package while peeling open a foil laminate
cover.
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The cavity 36 also includes a plurality of tick
1 marks 37 which are used to assist in holding a contact
lens fn the centered position in the cavity during the
removal of deionized water at one of the. post hydration
processing stations. The package carrier is also
equipped with an annular flange 39 which is used for
heat sealing a foil laminate cover in order to provide a
hermetic seal for the contact lens during final
distribution. A cut-out 35 may optionally be provided
to facilitate gripping the flange 38 and the package
when the cover stock or foil laminate is removed for
consumer usage.
Base member 34 also includes a smooth planar
surface 34(a) to provide a suitable engagement zone for
vacuum grippers on the upper side, and a vacuum rail on
the Lower side, which are used to transport the package
carrier during various stages of the operation.
An inspection carrier for transporting the package
carriers through the automated lens inspection system is
illustrated in Figure.7.- The inspection carrier 10
includes a first and second row 10(a),10(b) of cavities
40 which receive the bowl 36 of the package carrier and
provide an optical sight path for the automated lens
inspection system. Each of the intermediate
registration pins 4I engage a package carrier on either
side, with the end registration pins 41(a) engaging a
single package. These registration pins provide for
precise registration of the package carrier in the
longitudinal dimension of the inspection carrier while a
pair of hard edges 42(a),4Z(b) provide a reference
surface for the downwardly descending flanges
33(a),33(b), which together with pins 41 register the
carrier package against rotational skewing. The
inspection pallet 10 is further provided with three
registration openings 43 on either side of the pallet
-
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which are used to transport the pallet through the
1 automatic lens inspection station and to lock the pallet
in place during loading and unloading of the package
., carriers. The inspection pallet is further provided
with a pair of grooves 44(a),44(b) which provide a
positive grip for an overhead transport mechanism that
places and then removes the inspection pallet from the
automatic lens inspection system. A pair of slanted
faces 45 provide clearance for the downwardly descending
flange member 38 of the package carrier 20.
AS illustrated in Figure 3, an injection mold
machine 30 is used to mold the polypropylene package
carriers 20 which serve a dual purpose in the invention
concept. First, to provide a carrier for the inspection
of the lens by the automated lens inspection system, and
secondly, to provide a receptacle for the final
packaging of the Lens for distribution to end use
consumers. These package carriers are molded in
predetermined array, typically in clusters of sixteen
per mold cycle, and removed from the injection mold by a
r°botic transfer means 60 having a rapidly reciprocating
low mass transport carrier 62. The carrier 62 includes
a hand member 64 having a plurality of vacuum gripper
means thereon which are arranged to correspond to the
array of mold cavities within the injection molding
machine 20. Carrier 62 reciprocates along support
member 26 and is rotatable from a vertical orientation
as illustrated in Figure 3, to a horizontal orientation
necessary to place the packaged carriers into a
secondary transfer shuttle 68. Secondary transfer
shuttle 68 is used to transport a plurality, i.e.
sixteen of the package carriers from a first receiving
position 68(a) illustrated in Figure 3 to a second
position 68(b) where the package carriers are picked up
by a robotic handling device 50. Robotic handling
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device 50 is articulated, having first and second arms
1 51,52 and a vertically reciprocating arm and hand (not
shown) having a plurality of vacuum gripping means
thereon which engage each of the package carriers
transported by the transfer shuttle 68.
The package carriers 20 are then removed from the
transfer shuttle 68 and placed on an inspection pallet
at a pallet loading station 11. In the preferred
embodiment the package carriers are molded in a 4 X 4
array to maximize the efficiencies inherent in such an
10 array for molding, which are transported in the
inspection pallet ZO in a 2 X 8 array. When these two
arrays are used, robotic handling device 50 makes two
separate transfers, and transfers a 2 X 4 array in each
transfer. The loaded.pallet 10 is then moved by
1~ conveyor 12(a) to a deionized water injection station 16
wherein each of the package carriers transported on the
inspection pallet are partially filled with degassed and
deionized water. The inspection pallet is then
transferred by a push conveyor 17 to a lens loading area
18 where it is batched with a second pallet to provide a
contiguous loading area with thirty-two package
carriers, each of which has been dosed with degassed and
deionized water.
A first robotic transfer device 100 having a
plurality of convex lens carrier elements 110 mounted
thereon then removes thirty-two contact lenses from the
preceding hydration station as described in U.S. Patent
No. 5,476,111, entitled "Automated Method and Apparatus
for Hydrating Soft Contact Lenses".
The robotic transfer device 100 includes an
adjustable 4 X 8 array 102 of convex lens carriers 104
which pick up thirty-two lenses with a first 4 X 8
array, configuration, and deposits them in the batched
array of thirty-two package carriers at staging area 18,
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with a single lens in each package carrier. The contact
1 lenses are transferred from the hydration station to the
individual convex lens carrier 100 with a gentle puff of
air, and retained thereon by surface tension. The
robotic transfer array 102 ~s~paused at station 70 to
remove any air bubbles entrapped in the residual
deionized water that wets the lens. Station 70 includes
a plurality of specially configured air nozzles which
blow off the residual bubbles.
After the package carriers 20 have been loaded with
a contact lens, the inspection pallets 10 are singulated
by transport push plate 19 and loaded onto a first
overhead conveyor 21. The overhead conveyor 21 then
lifts the inspection pallet 10 from the lens loading
area and transfers it to the automatic lens inspection
system 15, and particularly to the conveyor 15(b) for
transport through the automatic lens inspection system.
After the lenses have been inspected, the inspection
pallet is lifted by the second overhead conveyor 22 and
placed on conveyor 12(b) for transport to the-deionized
water removal station 24. The deionized Water is
removed by a specially configured nozzle, as described in
EP Patent No. 618063, entitled "Solution Removal Nozzle".
The deionized water is used to center
the lens within the package carrier during the
inspection process, but is removed prior to packaging,
to enable a precise dosing of a buffered saline solution
in the final package.
After removal of~the deionized water, the lenses,
package carriers and inspection pallet are transported
to the package removal pick point 25 which clamps the
inspection pallet 10 to enable the second robotic
transfer device 200 to remove the package carriers and
lenses therefrom.
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A programmable logic controller maintains a status
1 register for each of the lenses as they are placed at
the robotic transfer staging area 18 and receives a flag
from the automatic lens inspection station 15 for each
lens that has failed inspection. The second robotic
transfer device 200 includes a Z X 8 array of
independently actuable vacuum grippers which engage the
package carriers at the package removal pick point 25.
Any packages containing out of spec lenses are then
dropped onto conveyor 14 by the robotic transfer device
200 as hereinbefore described, and the remaining lenses
are transferred to the consolidation buffer 230
illustrated in Figures 4, 5, 8 - 12.
The consolidation buffer 230 includes a pair of
vacuum rails 230(a),(b), cross sections of which are
illustrated in Figure 12, which receive the 2 X 8 array
of package carriers from the second robotic transfer
means 200. This 2 X 8 array is deposited on the
consolidation buffer 230 at position 230(c), as
illustrated in Figure 5. A pair of product followers
232,234 engage the string of package carriers and slide
them in the direction of arrow C until they engage other
package carriers on the consolidation buffer, or until
they trigger light sensors 236,238 as previously
described. If they encounter existing package carriers,
the followers 232,234 push the entire string in the
direction of arrow A until the string of package
carriers has triggered light sensors 236,238 illustrated
in Figure 1. At this point, the PLC logic controller
signals a pneumatic controller which reverses the
actuating air pressure for the product followers 232,234
causing them to withdraw. A product indexing pusher 240
then returns the product string in the direction of
arrow D to a fixed reference position where the package
carriers can be readily engaged by the third robotic
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handling device 300. The vacuum consolidation rails 230
1 exert a slight downward pressure on each of the package
carriers on the smooth planar area 34(a) to hold the
package carriers tightly to the rail and to prevent
shingling thereof when being driven forward by product
followers 232,234, or indexing pusher 240.
The packaging robotic transfer device 300 includes
a 2 X 5 array 302 of vacuum gripping means 304 which may
engage ten of the package carriers at the position
illustrated at 230(d) in Figure 5 for transfer to the
indexing turntable 400. The indexing turntable 400
includes a rotatable turntable having eight supgort
pallets 410 mounted thereon for receiving the 2 X 5
array of package carriers and contact lenses from the
packaging robotic transfer device 300.
In normal operation, the robotic transfer device
300 deposits the 2 X 5 array on support pallet 410 in
the number 1 position. If the indexing turntable is not
in operation, a large buffer area 308 is provided with a
plurality of buffer pallets, one of which is indicated
s~bolically at 310 in Figure 5. Buffer area 308 will
accommodate approximately fifty pallets for intermediate
storage, or approximately 10 minutes of product stream
in the event the packaging operation is temporarily
interrupted for resupply, maintenance or adjustments.
After the 2 X 5 array of package carriers has been
deposited on support pallet 410, the pallet is rotated
to position 412 where optical sensors verify that a
package has been loaded at each position and that the
packages are correctly aligned on the pallet. Indexing
turntable 400 is then rotated again to station 414
wherein each of the individual package carriers are
dosed with approximately 950 microliters of a buffered
saline solution. The use of deionized water in the
hydration and inspection steps significantly speeds, the
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production line as a whole since the time consuming
1 ionic neutralization of the polymer from which the
lenses are made does not occur until after the
., inspection process. When deionized water is used for
hydration and inspection, the 'final step of the process
~ is to introduce buffered saline solution into the final
package with the lens and then seal the lens within the
package so that final lens equilibration (ionic
neutralization, final hydration and final lens
dimensioning) is accomplished in the package~at room
temperature or during sterilization after the lens has
been packaged and sealed.
It has been determined empirically that it is
desirable that soft contact lenses produced in
accordance with the present invention be exposed to
atmosphere for no more than sixty minutes between the
removal of the deionized water at station 24
(illustrated in Figure 3) and the dosing of the saline
solution at station 414 in Figure 5. The programmable
logic controller which previously received the
inspection results from the automated lens inspection
system and correlated those results to the individual
lenses, also time stamps the individual lenses at the
pick up point 25, immediately following the removal of
the deionized water at station 24. This time stamp is
transferred through consolidation and into the 2 X 5
array when removed by the packaging robotic transfer
device 300. In the event the indexing turntable 400 is
not operational, and the 2 X 5 array is stored in the
buffer 308, then the X,Y coordinates of the 2 X 5 array
are stored with the time stamp to enable the packaging
robotic transfer device 300 to select "fresh" product,
i.e. less than sixty minutes old, at the time the
indexing turntable 400 resumes operation. After
operation is resumed, the r~botic transfer device 300
-
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will then dispose of the "expired" product, rather than
1 transferring it to the indexing turntable.
After saline dosing at station 414, the saline
level is checked at station 415 and the support pallet
is then rotated under a final~product check station 416
to a foil receiving station 418.
As described earlier, each group of package
carriers 20 receives a single laminated foil cover sheet
which is heat sealed to the package carriers. The lens
package is more fully described in EP Patent No. 650676,
entitled "Packaging Arrangement fox Contact Lenses", also
assigned to the assignee of the present invention.
The laminated
foil stock 432 is fed from a large indefinite spool
through a tensioning device 434 to an ink jet printer
436 which prints the lot, batch and power number of the
lenses to be packaged. The foil laminate is cut from an
indefinite length product into two strips that are heat
sealed to the 2 X 5 product array to provide two
separate 1 X 5 product strips. The foil in between each
of the package carriers is also partially severed,
scored or perforated to enable the consumer to separate
individual packages from the 1 X 5 array at the time the
product is used. The partial scoring is done with a
series of rolling blades 440(a)-(d) which are
pneumatically biased into a drum 439. The foil is then
split into two strips by a foil slitter blade 441 and
the foil passes through a stationary gripper and sensing
mechanism 442. A video camera 438 and a series of
sensors at station 442 are used to provide precise
alignment of the information printed by the ink jet
printer 436, with the printing fields into which said
printing is placed, and the alignment of the
perforations-or scores provided by rolling blades 439.
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An advancing gripper 434 is provided to draw a length of
1 foil laminate corresponding to the 1 X 5 array and sever
the strips with a rotating knife 444. At the completion
.. of this cut, the advancing gripper 434 has advanced in
the direction of arrow E in .Figure 4 to place the 1 X 5
foil strips under vacuum gripping heads 418(a),(b).
These vacuum gripping heads then reciprocate downwardly
to grip the foil, lift it from the advancing and cutting
station 434, and transfer the foil to the indexing
turntable 400 at the foil placement station 418.
The indexing turntable 400 is then rotated again,
and a heat seal mechanism 420 seals a single strip of
foil to five separate package carriers in a single high
temperature short cycle sealing operation. Indexing
turntable 400 is then rotated to position 422 where a
reciprocating transfer head 446 removes the sealed
product from the indexing turntable 400 and transports
it in the direction of arrow F for sterilization and
cartoning.
The Consolidation Buffer
The vacuum consolidation buffer of the present
invention will be described with respect to Figures 8 -
12 in which 230(a),(b) represent a pair of elongated
vacuum rails defined by housing members 231(a),(b) which
enclose vacuum plenums 242(a),(b) and which define a
plurality of vacuum slits 244(a),(b). While a single
elongated slot 244(a);(b) is depicted in Figure 12, and
a plurality of slots are depicted in Figure 8, it is
understood that a variety of aperture shapes and
arrangements could be used. As illustrated in Figure
12, the second robotic transfer device 200 includes a 2
X 8 array 202 of independently actuable vacuum gripping
'means 204 which pick a 2 X 8 array of package carriers
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from pick point 25, immediately following the removal of
1 the deionized water as previously described with respect
to Figure 3. The 2 X 8 array is then moved to position
230(c) as illustrated in Figure 5, and as illustrated
in
cross-section in Figure 12 wherein the individual
package carriers 20 are positioned immediately above the
vacuum rail, and then lowered into engagement therewith,
to enable the vacuum slits 244(a),(b) to engage the
smooth planar surface 34(a) of the package carrier 20.
The vacuum gripping means 204 are then released and the
package carriers 20 are then lightly gripped and secured
to the consolidation buffer vacuum rails 230(a),(b) by
a
vacuum drawn through plenum 242(a),(b). The purpose of
the vacuum rail is to prevent shingling of the
individual carrier packages when long strings of the
packages are moved by the product followers 232,234.
Each of the vacuum rails 230(a),(b) also define an
elongated trough 246(a),(b) which receives the bowl of
the package carrier 20 and product guides 250(a),(b)
which prevent lateral movement.of the package carrier
as
they are slid along the vacuum rail. After the package
carrier 20 has been seated on the vacuum rail as
illustrated in Figure 9, the package followers 232,234
advance the respective strings of product or package
carriers along the vacuum consolidation rail 230(a)(b)
in the direction of arrow C in Figure 8. As illustrated
in Figure 8, the product followers 232,234 are mounted
on pneumatically driven carriages, one of which is
visible in elevation view of Figure 8 and two of which
are visible in plan view in Figure 10. The carriage
3~ includes a rodless cylinder 250 mounted for
reciprocation on pneumatic cylinder 252 and guided by
guide rod 251. The product followers 232,234 are each
mounted to the respective carriages by virtue of a pair
of parallel rods 254(a),(b),254(c),(d) which are mounted
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for reciprocation within housings 250(a),(b). The
1 product followers 232,234 are biased into engagement
with the carriage members 250(a),(b) by means of springs
256.
The product string is advanced in the direction of
arrow C until they trigger one or both of the optical
sensors 236,238. When the optical sensors are
triggered, the programmable logic controller reverses
the pneumatic bias on rodless cylinder 252 and the
carriage 250 is then retracted to its original position
as illustrated in Figure 8. In addition, a proximity
sensor (not shown) at the end of the stroke will also
generate a signal to reverse the direction of carriage
250 if no product has been deposited on either of the
consolidation buffer rail 230(a),(b).
After the respective product streams have been
advanced from position 230(c) to the optical sensor 238,
a product indexing mechanism 240 is actuated to return
the product string to a predetermined location for
registration with the third robotic transfer device 300
which transfers product onto the packaging indexing
table 400. The product indexing mechanism 240 includes
a pneumatic cylinder 264 which retracts a push rod 266
and a pusher plate 262 into engagement with the product
stream on the vacuum consolidation rail. The product
pusher arm 262 then returns the leading edge of the
first package carrier on each vacuum rail to a
predetermined index position for registration with the
2 X 5 array 302 mounted on the packaging robotic
transfer device 300.
While the invention has been particularly shown and
described with respect to the preferred embodiments
thereof, it will be understood by those skilled in the
art that the foregoing, and other changes in form and
details, may be made therein without departing from the
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spirit and scope of the invention, which is limited only
1 by the scope of the following claims.
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