Automated apparatus and method for preparing contact lenses for inspection and packaging

Information

  • Patent Grant
  • RE37432
  • Patent Number
    RE37,432
  • Date Filed
    Thursday, November 18, 1999
    25 years ago
  • Date Issued
    Tuesday, November 6, 2001
    23 years ago
  • US Classifications
    Field of Search
    • US
    • 053 494
    • 053 495
    • 053 493
    • 053 500
    • 053 251
    • 053 235
    • 053 543
  • International Classifications
    • B65B5710
    • B65B5522
    • C08J700
Abstract
An apparatus is provided for removing and transporting articles, such as contact lens sections from a manufacturing line to inspection and packaging stations. The lenses are deposited in a transparent plastic primary package which carries the lenses through the inspection station and becomes part of the primary package when a cover is sealed thereto. The invention includes various assemblies, including lens transfer assemblies, deionized water filling and removal assemblies, a water degassing assembly, a lens inspection assembly, and a lens package sealing assembly. The lenses are removed from pallets at a post hydration station, transported and spatially redistributed, and deposited in the primary packages disposed on a second set of pallets. The packages on the second set of pallets are filled with degassed deionized water. The contact lenses and packages are then transported to an inspection station. After inspection, the lenses and packages are transported to a water removal assembly, and then to another transfer assembly. This transfer assembly separates those lenses which passed inspection from those which did not, and places those that did in a consolidating assembly. The lenses and packages are then filled with saline solution and a foil label is then sealed thereto to form the primary package.
Description




FIELD OF THE INVENTION




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 handling and preparing contact lenses for inspection and packaging.




DESCRIPTION OF THE PRIOR ART




The molding of hydrophilic contact lenses is disclosed in U.S. Pat No. 4,495,313 to Larsen; U.S. Pat No. 4,640,489 to Larsen, et al.; U.S. Pat. No. 4,680,336 to Larsen et al.; U.S. Pat. No. 4,889,664 to Larsen et al.; and U.S. Pat. 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 a 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. Pat. 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 reduces the thruput time by hydrating the lens and releasing the lens from the mold cavity with the deionized water and a small amount of surfactant without 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. Pat. 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 polypropylene blister and a foil laminate that is heat sealed thereto.




While U.S. Pat. Nos. 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 prepare the lenses for inspection and to handle the lenses at high production rates to 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 U.S. Ser. No. 07/993,756, now U.S. Ser. No. 08/598,069 entitled “Lens Inspection Method and Apparatus”, (VTN 0037) assigned to the assignee of the present invention. Further, recent developments in the hydration and automated handling of wet contact lenses, as taught in U.S. Ser. No. 08/258,556, now U.S. Pat. No. 5,476,111 “Automated Method and Apparatus for Hydrating Soft Contact Lenses” (Docket 8998), also assigned to the assignee in the present invention, has enabled automatic robotic handling of lenses during hydration, and prior to the inspection thereof by the automated lens inspection system.




It is an object of the present invention to provide an automated apparatus for handling and preparing contact lenses for inspection. It is further an object of the present invention to provide an automated apparatus for handling and preparing contact lenses for inspection and packaging wherein the lenses are inspected and packaged in the same carrier.




It is an object of the present invention to provide a robotic device for transferring a plurality of soft contact lenses from a first processing station to a second processing station wherein the robotic device includes an adjustable array of convex contact lens carriers thereon. The adjustable array is particularly useful for transferring contact lenses between processing stations wherein the first station includes a plurality of first contact lens carriers arranged in a first array with each of said carriers having a concave lens holding surface and a contact lens to be transferred therein. Each of these concave lens holding surfaces may also define a first fluid port for introducing a fluid between the concave surface and the lens. The robotic head which facilitates transfer of the lens between the processing station includes a plurality of second contact lens carriers in an adjustable array with each of the second carriers having a convex lens attachment surface which receives a contact lens thereon, and a second port for introducing a fluid between the contact lens and the convex lens convex surface. The robotic device may be equipped with articulated motorized arms and a control circuit for moving the robotic transfer head between the first and the second processing stations, and may further include a fluid supply means for supplying a fluid to the first and second fluid ports to thereby transfer the lens therebetween. The second processing station may include a second frame having a plurality of third contact lens carriers arranged thereon in a third array for receiving the contact lenses transferred thereto, wherein the arrangement of third array of contact lens carriers is not the same as the arrangement as the first array of first contact lens carriers, and the robotic transfer head includes an adjustable array for matching the first frame for contact lens pickup, thus changing its configuration to match the second frame for contact lens discharge.




It is further an object of the present invention to provide for transfer of the lens between carriers with degassed and deionized water to facilitate the inspection thereof in the automatic inspection means. It is further an object of the present invention to provide a device for removing air bubbles that may have formed on the surface of the lens prior to the inspection thereof in the automatic lens inspection system.




It is further an object of the present invention to provide an improved method of inspecting molded contact lenses wherein the lenses are inspected in deionized and degassed water to minimize the formation of air bubbles which would create false negative automatic lens inspection data.




It is further an object of the present invention to provide an improved method for manufacturing soft contact lenses wherein the lenses are first molded in disposable contact mold frames, and then hydrated and inspected in degassed and deionized water, and then packaged in a saline solution to enable the Lime consuming ionic neutralization of the polymerized lens to occur in the final package. It Is further an object of the present invention to provide the foregoing method of manufacturing with a consolidation step for removing defective lenses from the line of inspected lenses prior to packaging.




It is another object of the present invention provide for inspection of the contact lens in degassed and deionized water and to provide for the automatic removal of the deionized water following inspection thereof.




Finally, it is an object of the present invention to provide for a transfer of the contact lenses from the hydration station to the inspection station with a bubble blow off station to remove air bubbles that would otherwise create false negative automatic lens inspection reports.




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 described in U.S. Ser. No. 08/258,654 “Consolidated Contact Lens Molding” (Docket 9016) it is understood the present consolidation apparatus is equally suitable for the consolidation of lenses formed by lathe cutting wherein the hydrogel is maintained at a dry state while the 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 monomer to centrifugal force in a mold which has the 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:





FIG. 1

is a diagrammatic and plan view of an apparatus which fills a package carrier with degassed deionized water, removes the molded contact lenses from the final hydration stage, and places the contact lenses in a specially configured inspection pallet for the automatic optical inspection thereof.





FIG. 2

is an elevation view of the automated lens inspection system and the stations utilized in the handling of the lenses after hydration and prior to the automated lens inspection.





FIG. 3

is a plan view of the apparatus illustrated in FIG.


2


.





FIG. 4

is an elevation view of a consolidation buffer used in the present invention, and the packaging apparatus to which the consolidated product flow is transferred.





FIG. 5

is a plan view of the apparatus illustrated in

FIG. 4

illustrating both a consolidation buffer and a packaging buffer arranged immediately prior to the packaging apparatus.





FIG. 6

is a plan view of an articulated robotic transfer head having an adjustable array of convex lens carriers positioned immediately above a hydration carrier having a plurality of contact lenses therein.




FIG.


7


(a) is a cross-section and diagrammatic illustration of the transfer of a wet contact lens from the concave lens holding surface of a hydration carrier to the convex holding surface of the articulated robotic transfer head.




FIG.


7


(b) is a cross-section and diagrammatic illustration of a bubble blow off mechanism for removing air bubbles from the contact lenses that might otherwise create false negative automatic lens inspection results.





FIG. 8

is a diagrammatic and partially cross-section plan view of the articulated robotic transfer head in the expanded position, as viewed from above.





FIG. 9

is a diagrammatic and partially cross-sectioned illustration of the articulated robotic transfer head in plan view in a closed position, as illustrated from below.





FIG. 10

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.





FIG. 11

is an isometric view of an inspection carrier used to transport a plurality of the contact lens carriers illustrated in FIG.


10


through the automated lens inspection system.





FIG. 12

is a diagrammatic illustration illustrating the components of the deionized water degassing system of the present invention.





FIG. 13

is a detailed elevation view illustrating in section the degas unit used to degas the deionized water.





FIG. 14

is an elevation and side view of an apparatus used for filling package carriers with degassed and deionized water in accordance with the practice of the present invention.





FIG. 15

is a partially cross-section elevation and end view of the apparatus illustrated in FIG.


14


.





FIG. 16

is a diagrammatic illustration of on individuated robotic handling device transporting contact lens carriers to a vacuum rail consolidation buffer used in the present invention.





FIG. 17

is a diagrammatic illustration illustrating in conceptual form a consolidation buffer used in the present invention.





FIG. 18

is an elevation view of a vacuum rail consolidation buffer used in the present invention.





FIG. 19

is an enlarged plan view of the drive mechanism utilized in the vacuum rail consolidation mechanism of FIG.


18


.





FIG. 20

is a diagrammatic and partially cross-sectioned illustration of the apparatus used to fill the package carriers with saline solution in the final packaging of the present invention.





FIG. 21

is a partially cross-section and diagrammatic elevation front view of a heat sealing head and pneumatic press used to hermetically seal the package carrier of the present invention.





FIG. 22

is a partially cross-sectioned elevational side view of the apparatus illustrated in FIG.


21


.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS




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 co-pending application U.S. Ser. No. 08/258,654 entitled “Consolidated Contact Lens Molding”; hydrated in a hydration system as described in U.S. Ser. No. 08/258,556, now U.S. Pat. No. 5,476,111 entitled “Automated Method and Apparatus for Hydrating Soft Contact Lenses”; and automatically inspected as described in U.S. Ser. No. 07/993,756, now U.S. Ser. No. 08/598,068 entitled “Lens Inspection Method and Apparatus” are particularly benefited by the present invention.




Post Hydration Processing




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.




A suitable package carrier


20


is illustrated in FIG.


10


and is formed from injection molded or thermal formed plastic sheet material, such as polypropylene and includes a planar essentially rectangularly shaped base member


34


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

FIG. 10

, at the other end thereof which are used to align the package carrier for robotic handling. This package carrier is more fully described in co-pending application U.S. Ser. No. 995,607, the disclosure of which is incorporated here by reference thereto. 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. Pat. 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 subsequently assist in supporting the cavity structure of an inverted and superimposed package carrier when said packages are to be cartoned for final distribution.




The cavity


36


also includes a plurality of tick marks


37


which are used to assist in holding a contact lens in 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


is used to facilitate gripping the flange


38


and the package when the cover stock or foil laminate is removed by the consumer to use the lens.




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 FIG.


11


. 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


41


engage a package carrier on either side, with the end registration pins


41


(a) engaging a single package. These registration pins engage the registration notches


31


(a), (b) in the package carriers and provide for precise registration of the package carrier in the longitudinal dimension of the inspection carrier while a pair of hard edges


42


(a),


42


(b) provide a reference point 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 which are used to transport the pallet through the 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

FIG. 3

, an injection mold machine


30


is used to mold the polypropylene lens 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 a 4×4 cluster of sixteen package carriers per mold cycle, and removed from the injection mold by a robotic 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


30


. Carrier


62


reciprocates along support member


66


and is rotatable from a vertical orientation as illustrated in

FIG. 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

FIG. 3

to a second position


68


(b) where the package carriers are picked up by a robotic handling device


50


. Robotic handling device


50


is articulated, having first and second arms


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


10


at a pallet loading station


11


. In the preferred embodiment the package carriers are molded in a 4×4 array to maximize the efficiencies inherent in such an array for molding, which are transported in the inspection pallet


10


in a 2×8 array. When these two arrays are used, robotic handling device


50


makes two separate transfers, and transfers a 2×4 array in each transfer. The loaded pallet


10


is then moved by conveyor


12


(a) to a deonized 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 hatched 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.




Deionized Water Degas




The present invention utilizes degassed and deionized water with a small amount of surfactant therein as an inspection media for the Automatic Lens Inspection System described in U.S. Ser. No. 07/993,756, now U.S. Ser. No. 08/598,068.




When only deionized water is used in the package carrier bowl, friction or hydrophobic attraction between the contact lens and the surfaces of the carrier that form the recesses may occasionally prevent the lenses from moving or sliding completely into the desired, predetermined positions. For example, in one known process, contact lenses are formed from a liquid hydrogel monomer, which is polymerized in the presence of an inert diluent such as boric acid ester, as described in U.S. Pat. No. 4,495,313. The inert diluent fills up the spaces in the hydrogel lens during polymerization, and the diluent is subsequently exchanged for deionized water during a hydration process.




After this hydration process is completed, small amounts of the acid groups may remain on the lens surface. When the lens is placed inside the recess of the lens carrier, these acid groups may cause the lens to stick to the surface of the bowl of the carrier. Without freedom of movement, the lens might not move completely into the desired predetermined position. When this happens and the lens is subsequently inspected using an automatic Lens Inspection System, the lens may be rejected for being outside the field of view, or may otherwise be erroneously identified as irregular or imperfect.




In application U.S. Ser. No. 08/258,266, entitled “A Method of Positioning Ophthalmic Lenses”, the disclosure of which is incorporated herein by reference thereto, a solution to this problem was described in which a small amount of surfactant was added to the deionzed water. The surfactant reduces the friction and retards the hydrophobic attraction between the lens and the surface of the holder forming the recess, helping to insure that the lens is pulled into the desired, predetermined position.




Any suitable surfactant may be used in the practice of the invention. For example, the surfactant may be polyoxyethylene 20 sorbitan monooleate, more commonly known as Polysorbate 80, or tween 80 or tween 80 k


c


. It has been found that the addition of tween 80 at a concentration as low as 25 parts per million parts of solution allows the lens to move in package carrier


20


without sticking. Larger amounts of the surfactant may be used, and for example, the weight percent concentration of the surfacant in the solution may be between 5.0% and 0.01%. The surfactant may be mixed in any suitable liquid carrier, such as deionized water, to form the desired solution.




Preferably, the surfactant concentration in solution is in the lower end of the above-given range, and for example, the surfactant concentration may be below fifty parts per million parts of deionized water. Using the surfactant at this lower concentration helps to avoid, or to reduce, any foaming or bubbling of the surfactant in the solution and helps to reduce subsequently the surfactant concentration below a predetermined level.




Degassed water is preferred to the prevent the formation of air or gas bubbles when the water emerges from a pumped high pressure fluid line into a low pressure (atmospheric) environment. When deionzed water which has not been degassed is used, small air bubbles may form in the package before the lens is transferred or, on the contact lens when it is transferred to the package carrier. These bubbles are formed from dissolved gasses in the deionized water which are “seeded” by the lens or a small irregularity in the package carrier surface.




The apparatus for degassing the deionized water is illustrated in

FIGS. 12 and 13

.

FIG. 12

is a diagrammatic illustration of the degas module, while

FIG. 13

is a detailed elevation view as the degas unit. Deionized water is provided through input line


112


from a deionized water source, which may be the same source as that used for hydration. If drawn from a container, a optional pump


114


may be provide.




The deionized water then passes through filter


118


in order to remove extraneous particulate contaminates that may be present in the water.




The deionized water is then provided to the inlet


121


of the degas unit


122


. Within the degas unit, the deionized water is divided among a plurality of tubes


124


, and then recombined into a degas unit discharge


126


. The degas unit is operated under a low ambient pressure typically from 4 to 25 torr which is provided by vacuum pump


128


. This vacuum pump is attached to the degas unit


122


by line


130


and discharges the excess air from the degas unit by way of line


132


.




After the deionized water exits degas unit


122


by discharge line


126


, it passes through line


136


(a), (b) into manifolds


138


(a), (b). The manifolds are used as a common source to supply a plurality of precision dose pumps


140


that fill individual contact lens package carriers at the dosing station


16


and the robotic transfer array


102


mounted on robotic transfer device


100


. The pumps


140


used to pump the degassed and deionized water to manifold


138


are F.M.I. pumps (Fluid Metering, Inc., Oyster Bay, N.Y.) that are mounted to drive units manufactured by Oyster Bay Pump Works, Inc., Oyster Bay, N.Y. These pumps provide precision doses of degassed and deionized water solution to pre-wet the package surface thereby reducing bubble formation and lens sticking, to avoid overfilling (i.e. water on the sealing area of the package) and to promote the proper water level for the inspection system.




Turning now to

FIG. 13

, there is shown in greater detail the monomer degas unit


122


. The degas unit is comprised of a pressure boundary consisting of an outer cylindrical wall


144


, a top plate


146


and a bottom plate


148


. Contained within the cylindrical side wall


144


is a port


130


, which is connected to vacuum pump


128


(not shown).




Top plate


146


and bottom plate


148


are attached to the cylindrical side walls


144


by use of flanges


150


compressed upon O-rings


152


and


154


found on the bottom and top plates, respectively. Compression of the O-rings and attachments of plates


146


and


148


to flanges


150


is accomplished by bolts


156


that attach the plates to the flanges.




Passing through top plate


146


is the water inlet line


121


. This inlet line passes through the top plate


146


, divides within the chamber


122


by means of a “Y” connector into two or more lines


157


of equal length. Lines


157


are preferably of equal length in order to provide equal back pressure resulting in equal flow through both lines to two separate headers


158


. Each of these headers is connected to ten silicon tubes


160


which are permeable to gas. The tubes


160


are arranged in a 3- 4- 3 offset array, 0.300 spacing center-to-center. The flow through the tubes is from the bottom up in order to fill the tubes and not entrain voids in the liquid. A static mixer


170


is provided in each of the tubes


160


to increase the efficiency of mass transfer. These static mixtures are made of Delrin, ¼ inch in diameter and 6 inches long, as produced by Koflo, Inc. of Carrie, Ill.




The internal structure of the degas unit stands off the bottom of chamber with stainless steel pipe


167


supporting Delrin blocks


168


at the desired separation and these blocks, in turn, support manifolds


158


and


162


containing therebetween extended gas permeable tubes


160


. Alternately the degas unit may be suspended from top flange


146


.




During its time of residence in the silicon tube


160


in the low pressure degas chamber


144


, dissolved gasses migrate out of the deionized water through tube wall


160


, drawn out by the vacuum pump through chamber outlet


130


. As the water approaches the top of the chamber it is essentially free of dissolved gasses.




The silicon tubes near the top of the chamber are connected to second headers


162


which combine silicon tubes


160


back into common tubes


164


. These tubes may also be made of a silicon, or may be made of an impervious material. They are of the same length in order to avoid pressure differences which could result in flow imbalances. Tubes


164


are then connected in a Y fashion to provide a single degas unit outlet


26


.




The preferred material for the gas permeable tubing is STHT tubing produced by Sanitech Inc. of Andover, N.J. from Q74780 medical grade silicone rubber manufactured by Dow Corning of Midland, Mich.




The apparatus is arranged so that each set of tubes


124


contains ten tubes, each ½ inch inner diameter with a wall thickness of {fraction (1/32)} inch, having a 80 durometer hardness.




Pre-Inspection Preparation




The apparatus of the present invention that prepares the contact lenses for infection and subsequent packaging is best illustrated in

FIG. 1

which is an enlarged view of a portion of the apparatus illustrated in

FIGS. 2 and 3

with particular emphasis on the transition between the hydration line and the post-hydration line of the present invention.




The present invention is particularly adapted for use in conjunction with the invention disclosed in U.S. Ser. No. 08/258,556, now U.S. Pat. No. 5,476,111, entitled “Automated Method and Apparatus for Hydrating Soft Contact Lenses”, assigned to the assignee of the present invention, the disclosure of which is incorporated herein by reference thereto.




As illustrated in

FIG. 1

, a second hydration carrier


860


having a top chamber plate mounted thereon is advanced into the separation station


12


for removal of the top chamber plate and transferred to the return conveyor


141


. The hydration base emerges from the separation station


120


to the position illustrated at


860


(a) having a plurality, e.g., thirty-two contact lenses


8


therein, with a single lens carried in each of the convex lens carriers attached thereto. An articulated robotic transfer device


100


having an adjustable 4×8 array


102


of convex lens carriers then positions the array over the second hydration carrier


860


(a) as illustrated in FIGS.


6


and


7


(a).




As illustrated in FIG.


7


(a), a single contact lens


8


is carried within the concave lens carrier


861


and is positioned immediately below a convex lens carrier element


104


mounted on the 4×8 array


102


. The concave carrier


861


includes at least one post


862


for introducing a fluid between the surface of the concave lens carrier element, and the lens


8


. The fluid is supplied through a channel


866


cut into the lower side of upper plate member


867


, which communicates with a fluid manifold and a plurality of upstanding fluid connectors


863


which extend above the surface of the concave lens carrier elements


861


as best illustrated in FIG.


6


. The fluid connectors


863


are adapted to engage fluid couplings


864


formed on the underside of the 4×8 array


102


. Each of these couplings is connected to a fluid conduit


874


which supplies a transfer fluid for the transfer of the contact lens


8


from the concave lens holding means


861


to the convex lens holding means


104


.




In the embodiment illustrated in

FIG. 6

, and in particular for the transfer of contact lenses from the hydration carrier


860


to the robotic array


102


, a pneumatic fluid transfer is desired, and thus conduits


874


provide pressurized air to the coupling members


864


which in turn supply the pressurized air to fluid coupling


863


to the channel passageway


866


, and the port


862


.




As illustrated in FIG.


7


(a), the contact lens


8


is still wet having recently been hydrated and flushed in the hydration station. Further, the lens has been hydrated with deionized water having a small amount of surfactant therein which may be advantageously employed to promote the handling of the wet contact lens by centering the lens within the concave surface of lens holding means


861


. When the air pressure lines


874


are actuated, a puff of air will emerge through the port


862


and lift the contact lens upwardly from the surface of the concave carrier and into engagement with the convex lens carrier element


104


. While the lens will adhere to element


104


with or without the surfactant, the surfactant wets the surface of the convex carrier element


104


and promotes adhesion thereto by virtue of the surface tension of the deionized water and the surrounding atmospheric pressure. In the transfer, it is desirable to position each of the convex carrier elements


104


within 1.5 mm of the lens to ensure a direct and precise transfer.




After transfer of the lens


8


to the convex element


104


, the robotic transfer device then moves the array of lenses to a “bubble blow off” station


70


illustrated in FIG.


3


. In

FIG. 1

, the 4×8 array


102


overlies station


70


.




The bubble blow off station


70


includes a manifold arrangement similar to manifold


860


with a plurality of cup members


106


, each of which has a concave surface


108


of approximately the same configuration as the convex surface of the second lens carrier element


104


. While a concave surface such as surface


108


has been found to be desirable, a single jet device will also provide the same function. The concave surface


108


also includes at least one port


110


defined therein for admission of pressurized fluid through a central passageway


109


formed in the cup member. The use of a small amount of surfactant in the deionized water promotes the transfer of the lens from first to second carrier elements, but also enables the formation of small air bubbles


105


in the layer of deionized water which coats the contact lens


8


. By subjecting the lens to a jet of pressurized fluid, the small bubbles


105


are migrated outwardly and dissipated prior to the transfer of the lens to the inspection carrier. Removal of the air bubbles is desirable to avoid false negative reports from the automatic lens inspection system which is used to inspect the lenses. While pressurized air is used in the preferred embodiment of the invention, deionized water is also suitable.




Package Carrier Dosing




As was described earlier with respect to

FIGS. 12 and 13

, deionized water is degassed in a degas unit


122


and distributed by a plurality of precision dosing pumps


140


to a deionized water dosing station


16


, which is more fully illustrated in

FIGS. 14 and 15

. As illustrated in

FIG. 15

, a rubber belt conveyor


12


(a) having a pair of belts carries the inspection carrier


10


from the package carrier loading area


11


(illustrated in

FIG. 3

) to the deionized water dosing station


16


. A pneumatic stop


170


having a paul


171


is used to hold a series of inspection carriers


10


upstream of the dosing station


16


. When a new inspection carrier


10


is to be loaded, the pneumatic stop mechanism


170


retracts paul


171


, allowing the inspection carrier


10


to be carried into the dosing station on conveyor


12


(a). A separate set of jaws mounted on a pneumatic locking mechanism


172


(illustrated in

FIG. 1

) engage the inspection pallet


10


and hold it securely in position for package dosing. A plurality of dosing nozzles


174


are mounted on a horizontal reciprocating beam support member


176


and are connected to the F.M.I. pumps


140


by virtue of a plurality of tubing members


178


with a separate pump for each nozzle. Each of the nozzle members


174


terminates in a sixteen gauge teflon needle having an ID of 0.045 inches -0.048 inches which is suspended directly above the package carriers


20


, and more particularly, above the bowl member


36


. In operation, a pneumatic cylinder


180


which is fixably secured to support frames


181


and


182


reciprocates carriage member


184


, vertical supports


185


,


186


and the horizontal mounting beam


176


to enable the teflon needle tips to be lowered into the recessed bowl


36


of the package carriers


20


. The tips are reciprocated downwardly, and approximately 600 microliters of degassed and deionized water is injected therethrough to partially fill the bowl


36


. After the bowls are filled with the desired dosage, pneumatic cylinder


180


is actuated and the reciprocal support beam


176


is raised to lift the teflon needles free of the package carriers


20


. The use of a reciprocating dosing needle eliminates agitation or splashing in the dosing of the degassed and deionized water. Undue agitation or splashing may also lead to the enlargement of air and the formation of air bubbles which may generate a false negative inspection signal. The inspection carrier


10


is then advanced out of the dosing station


16


to the end of conveyor


12


(a) where it engages a push conveyor


17


, driven by a servo motor, which pushes the inspection carrier


10


across a stainless steel platform


19


to the lens loading area


18


. The lens loading area


18


is specifically designed to accommodate two inspection pallets


10


and provide a ganged array of thirty-two package carriers for receipt of thirty-two individual contact lenses. When these two inspection pallets


10


are in the lens transfer position


18


, tapered pins (not shown) engage registration cavities on the pallets (2 per pallet) and provide precise positioning during lens transfer.




While 2×8 and 4×8 arrays have been utilized in the post-hydration processing section of the present invention, it is understood that a variety of array configurations could be utilized in the practice of the present invention.




The 4×8 array of the hydration carrier


860


is different than the 4×8 array of package carriers in the lens loading area


18


. The second 4×8 array


102


mounted on robotic transfer means


100


is adjustable to accommodate the first 4×8 array in the second hydration carrier


860


which has 30 mm centers between lenses, and the “bubble blow off” station


70


, and then expands to 30×50 mm centers, which is the dimension of the third 4×8 array at the lens loading area


18


as will be hereinafter described with respect to

FIGS. 8 and 9

.




As illustrated in

FIGS. 8 and 9

, the 4×8 array


102


is illustrated in an expanded configuration in

FIG. 8

, and a collapsed configuration in FIG.


9


. The array


102


includes thirty-two convex lens carrier elements


104


as previously described with respect to

FIGS. 6 and 7

. Along the center line of the array are four fluid coupling members


864


which engage conduits


863


on the second hydration carriers


860


. The array is made of four separate lines or elements


190


-


193


, each of which caries eight convex carriers


104


. Each of the linear members


190


-


193


is mounted for reciprocation along internal guide rods


194


and


195


as more fully illustrated in

FIG. 8. A

pneumatic chuck


196


,


197


is positioned on either side of the array, and upon actuation draws the outer most elements


190


,


193


outwardly as illustrated in

FIG. 8

along the guide rods


194


,


195


. Bach of the outer most arrays


190


,


193


also carries a pair of internal sliding stops, one of which is illustrated in

FIG. 8

at


198


which draw the inner most linear elements


191


and


192


outwardly, with linear element


190


drawing linear


191


, and linear element


193


drawing linear element


192


. Compression springs


199


also assist in separating the linear elements of the array.




It should also be noted that the array


102


is rotatable about turntable


103


to provide for the proper orientation of the array when transferring lenses from the hydration station to the lens loading area. The robotic transfer device


100


also includes first and second articulated arms


107


,


109


and a vertical arm


105


having a reciprocal servo motor


106


(see

FIG. 2

) mounted therein which enables complete three dimensional movement of the 4×8 array between each of the various transfer points which the robotic transfer device serves. As illustrated in

FIG. 2

, the weight of the


102


is substantially offset by a preload spring


108


which carries much of the weight of arm


105


and array


102


, thereby reducing the load on vertical servo motor


106


.




Each of the convex lens carrier elements


104


also includes an interior conduit


110


terminating in at least one port


111


which may be used to introduce a fluid between the convex lens carrier element and the contact lens


8


. When the array


102


is positioned over the plurality of lens carrier elements at the lens loading area


18


, the array elements


191


-


193


are spread to align each of the convex lens carrier elements


104


with an associated package carrier immediately therebelow, and a small amount, nominally 300 μl, of degassed and deionized water is pumped by precision dosing pumps


140


through conduit


110


to transfer the contact lens


8


from the convex carrier


104


to the bowl


36


of the package carrier


20


. Again, the use of degassed deionized water enables transfer of the lens without risking the development of small air bubbles from dissolved gasses in the deionized water that might otherwise “seed” on the contact lens


8


. After the lenses


8


have been transferred to the package carrier


20


, the 4×8 array


102


is collapsed by actuating air chucks


196


,


197


, to return the array to a configuration that matches the configuration of the hydration carrier


860


.




When both pair of inspection carriers


10


have been loaded at the lens loading area


18


, a second servo motor actuated push arm


18


(a) transfers both pallets from the lens loading area to a sag area


19


(a) as illustrated in FIG.


1


. At staging area


19


(a), an overhead double axis transport carrier


21


singulate one of the inspection carriers and picks up a single pallet


10


for transfer to the automatic lens inspection station


15


as illustrated in

FIGS. 1 and 3

. The overhead transport


21


is a double axis Hauser Transport Mechanism, and is used to isolate the automatic lens inspection system


15


from the remainder of the post-hydration line. By utilizing a double axis transport mechanism, the pallet


10


can be gently conveyed to the automatic lens inspection system, and thereby avoid any vibration that might otherwise impair the inspection results. After the first pallet


10


has been lifted from the staging area


19


(a), a push arm


19


moves the remaining pallet


10


(b) into the staging area


19


(a) for transfer by the double axis transport mechanism


21


to the Automatic Lens Inspection System


15


, as illustrated in

FIGS. 2 and 3

.




In the Automatic Lens Inspection System illustrated in

FIG. 3

, as the inspection carriers are conveyed through the system by conveyors


15


(b) a light beam or pulse is directed from sources


15


(c) and through a lens to be directed and focused on a screen (not shown) to produce an image of the lens therebelow. Preferably, the screen includes an array of pixels, each of which generates a respective one electric signal proportional to, or representing, the intensity of the light incident on the pixel. Those electric signals are then processed to determine if the lens is acceptable for consumer use. Any suitable procedure may be used to process or analyze the electric signals from the pixel array; and, for instance, suitable procedures are disclosed in copending patent application Ser. Nos. 993,756 and 995,281, entitled “Automatic Lens Inspection System”, the disclosures of which are herein incorporated by reference. As illustrated in

FIGS. 3

, separate systems are utilized to inspect the sixteen lenses carried in inspection carrier


10


. After completing the test for the last bank of lenses, the Automatic Lens Inspection System sends a datablock with the vision inspection results to the programmable logic controller used to consolidate the lenses for packaging.




After the lenses have been inspected by the automatic lens inspection system


15


, the inspection pallet is lifted by the second double axis overhead transport


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 U.S. Ser. No. 07/999,234, now U.S. Ser. No. 08/531,372 entitled “Solution Removal Nozzle”, the disclosure of which is hereby incorporated herein by reference thereto. As described earlier, 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, as will hereinafter be described in detail.




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


100


to enable a second robotic transfer device


200


to remove the package carriers and lenses therefrom.




The Consolidation Buffer




As illustrated in

FIGS. 2

,


3


and


16


, the second robotic transfer device


200


is positioned adjacent conveyors


12


,


13


and has mounted thereon a 2×8 array


202


of sixteen independently actuable vacuum gripping means. Inspection pallet


10


(b) is conveyed along conveyor


12


to a predetermined product pick point


25


, as illustrated in FIG.


3


and the 2×8 array


202


is positioned thereabove to remove each of the sixteen products from the inspection carrier


10


(b), immediately following the removal of the deionized water as previously described with respect to FIG.


3


.




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 vision datablock from the automated inspection system having a flag set for each of the products in inspection carrier


10


(b) that is out of product specification.




After the products


20


have ben removed from the inspection carrier


10


(b), the robotic transfer device


200


positions the 2×8 array over conveyor belt


14


and selectively discharges the out of spec products. 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


230


(c). The vacuum consolidation buffer of the present invention will be described with respect to

FIGS. 16-19

in which


230


(a), (b) diagrammatically 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).




The product array as deposited at


230


(c) includes gaps or random variations in the product flow resulting from the removal of the defective products from the serial product flow. The vacuum consolidation buffer


230


includes a pair of pneumatic product followers


232


,


234


which are used to consolidate the product group


230


(c) with the other already consolidated products on consolidation rail


230


.




Each of the pneumatic followers


232


,


234


is independently advanced in the direction of arrow C until each product stream is consolidated, thereby eliminating gaps or voids in the product stream which result from the inspection and rejection of defective products. For example, 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 both product streams 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


230


(a),


230


(b) 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” or overlapping of adjacent edges of product packages which might otherwise occur during consolidation.




As illustrated in

FIGS. 18 and 19

, the product followers


232


,


234


are mounted on pneumatically driven carriages, one of which is visible in elevation view of FIG.


18


and two of which are visible in plan view in FIG.


19


. The carriage 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 for reciprocation within housings


250


(a), (b).




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 FIG.


18


. 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 actuate 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 actuates a push rod


266


and a pusher plate


262


into engagement with the product stream on the vacuum consolidation rails. The product pusher arm


262


then returns the leading edge of the first package carrier on each vacuum rail to a pedetermined index position for registration with the 2×5 array


302


mounted on the packaging robotic transfer device


300


.




Packaging Transfer




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 griping means arranged in a 2×5 matrix. The 2×5 array


302


is first positioned over product group


20


(d) and the vacuum gripping means is actuated to withdraw the first ten products from the vacuum consolidation buffer


230


. The packaging robotic handling device


300


then positions the 2×5 array and product group


20


(d) over position


1


on the packaging indexing table


400


, and drops the array of products onto support pallet


410


mounted on the packaging indexing table


400


.




During packaging, the package indexing turntable


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 package indexing turntable


400


, the incoming product arriving on consolidation buffer


230


may be 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 2×5 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


388


. 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 sensitive product, and will transfer only product meeting the time sensitive criteria to the support pallet


410


. Likwise, 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


(d) 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 2×5 product array. 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.




Packaging




After the 2×5 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 microliter of a saline solution.




Station


414


is illustrated in elevation view in

FIG. 20

, wherein five dosing nozzles


415


are positioned above five package carriers


20


. Dosing nozzles


415


are mounted on a cantilever support arm


450


to thereby suspend the nozzle over the rotating table


400


. A plurality of saline tubes


417


carry a buffered saline solution, from a plurality of precision dosing pumps, similar to the F.M.I. pumps used to pump the deionized water to dosing station


16


depicted in

FIGS. 1 and 3

.




The use of deionized water in the hydration and inspection steps significantly speeds the production line as a whole since the time consuming 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

FIG. 3

) and the dosing of the saline solution at station


414


in FIG.


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 2×5 array when removed by the packaging robotic transfer device


300


. In the event the indexing turntable


400


is not operational, and the 2×5 array is stored in the buffer


308


, then the X, Y coordinates of the 2×5 array are stored with the time stamp to enable the packaging robotic transfer device


300


to select “fresh” product, e.g., less than sixty minutes old, at the time the packaging dial


400


resumes operation. After operation is resumed, the robotic transfer device


300


will then dispose of the “expired” product, rather than transferring it to the packaging dial.




After saline dosing at station


414


, the same 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 5 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 U.S. Ser. No. 995,607, entitled “Packaging Arrangement for Contact Lenses”, also assigned to the assignee of the present invention, the disclosure of which is incorporated herein by reference thereto.




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 package. The foil laminate is cut from an indefinite length product into two strips that are heat sealed to the 2×5 product array to provide two separate 1×5 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 1×5 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 gripping 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


. An advancing gripper


434


is provided to draw a length of foil laminate corresponding to the 1×5 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

FIG. 4

to place the 1×5 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 package indexing turntable


400


at the foil placement station


418


.




The package 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.




As illustrated in

FIGS. 21 and 22

, the foil strips are heat sealed to the two 1×5 arrays of package carriers


20


. A heated seal head


510


, heated by a plurality of electric heaters


512


(two of which are illustrated in the element of

FIG. 22

) mounted in a heating plate


514


. The heating plate


514


is secured to the back of the seal head


510


, and is supported by a pneumatic cylinder or press


516


which presses the heated seal head


510


against the laminar foil sheet on the package carriers


20


, which are supported by the pallet


410


such that the foil laminate and package carrier flanges are squeezed between the heated seal head and the pallet


410


as supported by the index turntable. The heated seal head is electrically heated, and the temperature thereof is measured by thermocouples


518


on each side of the seal head


510


to maintain the temperature at a high temperature, when compared to similar prior art arrangements. The temperature is maintained in a range from 210°-265° C., preferably at


258


° C.




The heated seal head comprises a 2×5 array of cylindrical sealing elements


520


, each of which secures one of the foil laminar sheets to each group of package carriers


20


with an annular seal


39


around the cavity


36


in the package carrier


20


. The pneumatic cylinder is coupled to the heated seal head by a mount jack bolt


522


and cylindrical support struts


524


. The support struts


524


are biased upwardly by springs


526


, such that the heated seal head is raised and normally biased to the upper position illustrated in

FIG. 21

, unless the pneumatic cylinder


516


forces it down for a sealing operation.




In operation, the back force generated by the pneumatic cylinder is measured by an in-line load cell


528


, and a solid state timer is initiated when a force is reached of approximately 2700 newtons, which is approximately 75% of the peak force of approximately 3600 newtons. The solid state timer times a relatively short time period of approximately 0.4 to 0.48 seconds, after which the pressure in the pneumatic cylinder


516


is released. This approach, when compared with similar prior art approaches, is very hot, very hard and very short, which creates a seal which is both detachable and customer friendly.




The package indexing turntable


400


is preferably reinforced under the seventh angular position to withstand the heat sealing forces imparted thereto by the pneumatic cylinder


516


. The indexing turntable


400


must be maintained in a substantially level position for the operations described herein. The pneumatic cylinder


516


at the seventh position applies a substantial force to the indexing turntable, and accordingly to maintain the turntable level, an approximately 2½×3½ inch support block


530


of a durable plastic material, similar to Teflon®, is placed on top a central support


532


and surrounding supports


534


positioned beneath the pneumatic press. The support block


530


is in constant contact with the indexing turntable


400


to ensure that the deflection of the indexing turntable


400


under the pneumatic cylinder


516


is minimal. Alternatively, a pneumatically actuable movable support could be positioned in contact with the bottom of the indexing turntable prier to operation of the pneumatic cylinder driving the heated seal head, and be repositioned out of contact with the bottom of the table after operation of the pneumatic cylinder.




The package 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.




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 spirit and scope of the invention, which is limited only by the scope of the following claims.



Claims
  • 1. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, said apparatus comprising:(a) an inspection pallet for transporting a plurality of contact lens packages, each of said packages adapted to receive a contact lens for inspection thereof; (b) an automatic lens inspection station for optically inspecting a plurality of contact lenses carried in said packages transported by said inspection pallet and generating a first signal for each defective lens; (c) an articulated robotic transfer device for periodically transferring a first predetermined number of individual packages from said inspection pallet to an intermediate consolidation buffer and depositing said packages on said consolidation buffer; (d) a controller for tracking and identifying each individual contact lens inspected and conveyed from said inspection station to said consolidation buffer, said control means including means for storing said first signals identifying individual contact lenses determined to be defective and generating a second signal to cause said articulated robotic transfer device to discard any individual contact lens identified by said inspection station as being defective prior to the deposit of said package on said consolidation buffer; and (e) second robotic transfer device for transferring a second predetermined amount of individual packages from said consolidation buffer to a packaging station during a period of operation.
  • 2. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, as claimed in claim 1, wherein said consolidation buffer consolidates random variations in a flow of individual packages to provide said second predetermined amount for said second robotic transfer device.
  • 3. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, as claimed in claim 1, wherein said control means further includes means for determining whether said packaging station is available to receive said second predetermined amount of packages at said period of operation, said control means further directing said second robotic means to transfer said second predetermined amount of packages to an intermediate storage means when it is determined that said packaging station is not available to receive said second predetermined amount of packages during said period.
  • 4. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, as claimed in claim 3, wherein said control means directs said second robotic transfer device to retrieve said second predetermined amount of packages from said intermediate storage means and transfer said packages to said packaging station when said packaging station is available to receive said package carriers.
  • 5. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, as claimed in claim 4, wherein said control means further includes timing means for generating first time stamp data for each identified package in said first predetermined amount of packages prior to transferring said first predetermined amount from said inspection station.
  • 6. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, as claimed in claim 1, wherein said predetermined amount of packages includes an X, Y array of packages, and said consolidation buffer includes at least X number of individual buffers.
  • 7. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, as claimed in claim 6, wherein said control means stores a status for each of said X number of individual buffers, including a count for each addition of packages, and a count for each second predetermined amount transferred to said packaging station.
  • 8. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, as claimed in claim 7, wherein said articulated robotic transfer device includes an array of independently actuable vacuum gripping means for gripping said packages.
  • 9. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, as claimed in claim 8, wherein said articulated robotic transfer device will transfer packages between individual buffers to complete said X, Y array of packages for said second robotic transfer device.
  • 10. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, as claimed in claim 1, wherein said apparatus further includes a deionized water injection station for injecting a predetermined amount of deionzed water into each of said packages.
  • 11. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, as claimed in claim 10 wherein said deionized water injection station injects said deionized water into each of said packages before said package receives said contact lens.
  • 12. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, as claimed in claim 10 wherein said apparatus further includes a station for removing said deionized water after said contact lenses have been inspected at said inspection station.
  • 13. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, as claimed in claim 10, wherein said apparatus further includes a degas apparatus to degas the deionized water before the injection of said deionized water into said packages.
  • 14. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, as claimed in claim 1 wherein said apparatus further includes a robotic array for transferring an array of individual contact lenses from a hydration station to a load station having an array of said packages in said inspection carrier positioned to receive said contact lenses.
  • 15. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, as claimed in claim 14, wherein said robotic array comprises:(a) a robotic transfer head, said head facilitating transfer of said lens from said hydration station to said load station, said transfer head also having; (i) a plurality of contact lens carriers, each of said carriers defining a convex lens attachment surface to receive a contact lens and a second fluid means for introducing a fluid between said contact lens attachment surface and said convex surface, said lens being retained thereon during transfer by surface tension; (ii) a robotic transport for moving said transfer head from said hydration station to said load station; (b) fluid supply means for supplying at least one fluid to each of said contact lens carriers; wherein said contact lenses are transferred to said apparatus by said robotic transfer head, and deposited into said packages by an injection of a fluid which breaks the surface tension between said contact lens attachment surface and the contact lenses carried thereon.
  • 16. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, as claimed in claim 1 wherein said apparatus further comprises:(a) a robotic transfer head, said head facilitating transfer of said contact lenses from a hydration station to an array of said packages carried by said inspection pallet at a load station, said transfer head also having; (i) a plurality of contact lens carriers, each of said carriers defining a convex lens attachment surface to receive a contact lens and at least one fluid port defined therein for introducing a fluid between said contact lens and said convex surface; (ii) an articulated transport for moving said transfer head from said first processing station to said second processing station; (b) a blow-off station, said station having a plurality of concave surfaces with at least one port in each surface for introducing a fluid jet therethrough, said plurality aligned to cooperate with said plurality of convex lens attachment surfaces to direct said fluid jets against said contact lenses being transported by said transfer head; (c) said controller also actuating said articulated transport and said fluid jets to align said convex carriers with said concave surfaces and to dissipate any air bubbles on said contact lens with said fluid jets.
  • 17. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, as claimed in claim 1, wherein said apparatus further includes a defective lens conveyor positioned between said inspection station and said consolidation buffer to receive defective lenses discarded by said articulated robotic transfer device.
  • 18. An automated apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility, as claimed in claim 17, wherein said articulated robotic transfer device includes an array of independently actuable vacuum griping means for gripping said packages, wherein said articulated robotic transfer device can discard said defective lenses by pausing over said conveyor and individually releasing the vacuum gripper for any defective lens over the defective lens conveyor.
  • 19. An automated robotic transfer apparatus for automatically inspecting and packaging contact lenses in a contact lens fabrication facility having an automatic lens inspection station which optically inspects each contact lens and generates a first signal for each defective lens, said apparatus comprising:(a) a robotic transfer head, said head facilitating transfer of said lens from a processing station to a package load station, said robotic transfer head also having; (i) a plurality of contact lens carriers, each of said carriers defining a convex lens attachment surface to receive a contact lens and a means for introducing a fluid between said contact lens attachment surface and said contact lens, said lens being retained thereon during transfer by surface tension; (ii) a robotic transport for moving said transfer head from said first processing station to said package load station; (b) fluid supply means for supplying at least one fluid to each of said contact lens carriers and said means for introducing a fluid, wherein said contact lenses are transferred to said package load station by said robotic transfer head, and deposited into packages at said package load station by an injection of said at least one fluid which breaks the surface tension between said contact lens attachment surface and the contact lenses carried thereon; and (c) a controller for tracking and identifying each individual contact lens inspected, said controller including means for storing any first signals identifying individual contact lenses determined to be defective and generating a second signal in response thereto to discard any individual contact lens identified by the inspection station as being defective; (d) said controller also controlling the injection of said at least one fluid between said contact lens attachment surface and the contact lens to thereby transfer said contact lenses to said packages.
  • 20. An automated robotic transfer apparatus as claimed in claim 19, which further includes an inspection means that generates a light pulse which is directed through the lens to a pixel array to generate an electrical signal which is processed to determine if the lens is acceptable and to generate said first signal if said lens is defective.
  • 21. An automated robotic transfer apparatus as claimed in claim 20, which further includes a consolidation apparatus for consolidating lenses determined to be acceptable after said defective lenses have been discarded.
  • 22. An automated robotic transfer apparatus for automatically packaging contact lenses in a contact lens fabrication facility, said robotic apparatus comprising:(a) a robotic transfer head, said head facilitating transfer of said contact lenses from a processing station to a package load station, said transfer head also having; (i) a plurality of contact lens carriers, each of said carriers defining a convex lens attachment surface to receive a contact lens and a first means for introducing a fluid between said convex lens attachment surface and said contact lens, said contact lens being retained thereon during transfer by surface tension; (ii) a robotic transport for moving said robotic transfer head from said processing station to said package load station; (b) fluid supply means for supplying said fluid to each of said first means, wherein said contact lenses are transferred from said processing station to said package load station by said robotic transfer head, and deposited into packages at said package load station by an injection of said fluid through said first means which breaks the surface tension between said convex lens attachment surface and the contact lens carried thereon; and (c) a controller for automatically controlling said robotic transport, positioning said robotic transfer head, and initiating injection of said fluid through said first means to thereby transfer said contact lenses to said packages.
  • 23. An automated robotic transfer apparatus as claimed in claim 19 or 22, wherein said contact lenses are arranged in an array, and said contact lens carriers are arranged in a corresponding array to facilitate the transfer of contact lenses to said plurality of contact lens carriers.
  • 24. An automated robotic transfer apparatus as claimed in claim 23, wherein said packages at said package load station are also arranged in a corresponding array to facilitate the transfer of contact lenses to a plurality of packages at said package load station.
  • 25. An automated robotic transfer apparatus as claimed in claim 19 or 22, wherein said contact lenses are arranged in an array of concave carriers, and are wetted with a solution having a small amount of surfactant therein prior to transfer to said plurality of contact lens carriers.
  • 26. An automated robotic transfer apparatus as claimed in claim 25, wherein the surfactant wets the surface of the contact lens carrier to promote surface tension adhesion of the contact lenses to the contact lens carriers.
  • 27. An automated robotic transfer apparatus as claimed in claim 19 or 22, wherein said apparatus further includes a package dosing station to fill each package with a precise dose of buffered saline solution prior to sealing.
  • 28. An automated robotic transfer apparatus as claimed in claim 27, wherein said apparatus further includes a package sealing station to heat seal a plurality of said packages to a foil laminate so that final lens equilibrium is accomplished after the lens has been packaged and sealed.
  • 29. An automated robotic apparatus for automatically transferring an array of wet slippery contact lenses in a contact lens fabrication facility, said robotic apparatus comprising:(a) a robotic transfer head, said head facilitating transfer of said array of contact lenses from a processing station to a package load station, said transfer head also having; (i) an array of contact lens carriers corresponding to said array of contact lenses, each of said carriers in said array defining a convex lens attachment surface to receive a contact lens and a first means for introducing a fluid between said convex lens attachment surface and said contact lens, each said contact lens being retained thereon during transfer by surface tension; and (ii) a robotic transport for moving said robotic transfer head from said processing station to said package load station, wherein an array of packages at said package load station are arranged in an array corresponding to said array of contact lens carriers to facilitate the transfer of said array or contact lenses to said array of packages at said package load station; (b) fluid supply means for supplying said fluid to each of said first means, wherein said array of contact lenses are transferred from said processing station to said package load station by said robotic transfer head, and deposited into said array of packages at said package load station by an injection of said fluid through each of said first means which breaks the surface tension between each said convex lens attachment surface and the contact lens carried thereon to thereby transfer said array of contact lenses to said array of packages; and (c) means for automatically controlling the positioning and depositing of said array of contact lenses into said corresponding array of packages.
  • 30. An automated robotic apparatus as claimed in claim 29, wherein said contact lenses are arranged in an array of concave carriers, and are wetted with a solution having a small amount of surfactant therein prior to transfer to said plurality of contact lens carriers.
  • 31. An automated robotic apparatus as claimed in claim 30, wherein the surfactant wets the surface of the contact lens carrier to promote surface tension adhesion of the contact lenses to the contact lens carriers.
  • 32. An automated robotic apparatus as claimed in claim 29, wherein said apparatus further includes a package dosing station to fill each package with a precise dose of buffered saline solution prior to sealing.
  • 33. An automated robotic apparatus as claimed in claim 32, wherein said apparatus further includes a package sealing station to heat seal a plurality of packages to a foil laminate so that final lens equilibrium is accomplished after the lens has been packaged and sealed.
Parent Case Info

This is a divisional of application Ser. No. 08/258,557, filed on Jun. 10, 1994, now U.S. Pat. No. 5,578,331.

US Referenced Citations (6)
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4640489 Larsen Feb 1987
4918907 Rozh et al. Apr 1990
5035105 Qvarnstrom Jul 1991
5488815 Abrams et al. Feb 1996
5528883 Jamison Jun 1996
5561970 Edie et al. Oct 1996
Foreign Referenced Citations (3)
Number Date Country
0 183 324 A2 Jun 1986 EP
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Divisions (1)
Number Date Country
Parent 08/461826 Jun 1995 US
Child 09/442934 US
Reissues (1)
Number Date Country
Parent 08/461826 Jun 1995 US
Child 09/442934 US