MXPA97000219A - Provision with rotating orientation for the deposition in b curves - Google Patents

Abstract

An arrangement with rotational orientation for deposition in base curves for assembling base curves and front curves of contact lenses with a prescribed and programmable angular orientation to produce a contact lens having a selected location of the axis therein, such as a toroidal shaft for a toroidal contact lens. A mold arrangement is provided for frontal curves in a support pallet with a dosed amount of the monomer mixture deposited in each of the molds for frontal curves. A deposition tube arrangement is used, placed on a support track and coupled to a vacuum source to receive and support a deposition of molds for base curve. Each of the deposition tubes on the support plate is then angularly rotated to a selected position angularly oriented therein. The common angular rotating mechanism is coupled to each of the deposition tubes in the arrangement to angularly orient each of the deposition tubes to a precise angular position on the support plate. The common angular rotary mechanism is driven by a stepper motor which can be controlled programmatically to change the selected angularly oriented position. The stepper motor drives movable zippers, which drive pinions around the deposition tubes. The angularly oriented arrangement of the molds is then assembled for base curves on the arrangement of the molds for froth curves to produce toroidal lenses having first and second optical surfaces that are angularly oriented with precision with respect to each other.

Description

DISPOSAL WITH ROTATING ORIENTATION FOR Lñ DEPOSITION IN BASE CURVES BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION The present invention relates generally to an arrangement with rotating orientation for the deposition in base curves for molding contact lenses, and more particularly belongs to an arrangement with toroidal orientation for the deposition in base curves to assemble base curves and frontal curves toroids in a prescribed angular orientation and programmable between them in a single step operation. The present invention allows a single type of mold for base curve to be selectively rotated to a set of different angular positions relative to a mold for front curve to produce different toroidal contact lenses having a toroidal curve axis placed in a set of different angular positions. Although the specific embodiment discussed therein relates to toroidal contact lenses, the present invention has a wider field of application and can be used for any lenses in which the two optical surfaces require different rotational orientations, such as for some lenses of imperfect spherical contact, or in which an inversion mark is desired at a particular angular location of the lens. 2. DISCUSSION OF THE PREVIOUS TECHNIQUE It is known that for astigmatic individuals, the astigmatic eye forms an image that contains three main regions: 1.- The spherical power is focused as a line; 2.- The cylindrical power is also focused with a line, perpendicular to the spherical line of the image; 3.- In the middle of the two, a circular image is formed, known as the "minimum confusion circle". Toroidal contact lenses are usually prescribed for astigmatic patients with astigmatism, either corneal or lenticular and have an optical surface / cylindrical power that is used to correct astigmatism in the user. Statistically, astigmatism usually occurs in people primarily either around the horizontal axis or the vertical axis, but also at varying axial locations with respect to them. In the prior art, a separate type of toroidal contact lens is required for each different toroidal optical power and also for each different orientation of the toroidal cylindrical axis of the contact lens, which is required to adapt to different patients with different amounts of astigmatism. conformity with the different axes. According to the above, an invention of the toroidal contact lenses, or plastic parts by molding to mold the toroidal contact lenses, includes a large number of different combinations of toroidal locations on the axes and toroidal optical powers. In the conventional designs of the toroidal contact lenses according to the prior art, a single toroidal surface consisting of a major axis and a minor ee is placed in the optical portion either of the frontal or base curve surface, by usually the surface of the base curve. In addition, the axes of the toroidal lenses are generally stabilized in relation to the patient's corneal axis by the use of either a plate or reinforcement feature with prisms or a double plate feature placed on the front surface of the lens . Commonly, toroidal lenses according to the prior art are manufactured with the following design characteristics: a.- a toroidal curve in the front or base surface of the lens; b.- reinforcement characteristics with prism and plate on the front surface of the lens; c- the non-toroidal surface is spherical. These lens designs according to the prior art correct the astigmatism suitably only if the axis of the cylindrical power is exactly aligned with respect to the e e of the astigmatic cornea. The misalignment of the e is (greater than 10 °) results in a considerable loss of visual acuity. Conventional toroidal lens designs require a large number of maintenance units in existence (UMES) in the inventory (the total amount of different prescriptions that can be kept in existence and that can be extended) in order to adjust a broad base of astigmatic patients. For example, the regular products of toroidal lenses of frequent replacement are available in 800 maintenance units in stock per base curve in the inventory (40 spherical powers x 2 cylindrical powers x 10 different locations of cylindrical axes). Such a large number of maintenance units in existence per base curve in the inventory is uneconomical to produce and maintain, particularly a product of disposable modality. The large number of required maintenance units in stock in the inventory arises mainly from the need to provide 10 or more different cylindrical shaft locations. In addition, any significant misalignment of the cylindrical axis with respect to the axes of the eye usually results in a significant loss of visual acuity, and therefore the exact alignment of the cylindrical axis is a primary requirement of talee lenses.

BRIEF DESCRIPTION OF THE INVENTION Therefore, it is a principal object of the present invention to provide an arrangement with rotational orientation for deposition in base curves for molding lenses such as contact lenses or intraocular lenses. A further object of the invention in question is the addition of a toroidal orientation arrangement for the deposition in base curves for assembling base curves and toroidal frontal curves with prescribed and programmable angular orientation therebetween in an assembly operation of single step The present invention allows a unique type of mold for base curve to be selectively rotated to a set of different angular positions relative to the front curve mold to produce different toroidal contact lenses having the axis of the toroidal curve located at a set of different angular poems. In accordance with the teachings of this, the present invention provides a method and apparatus for producing a molded lens having a first optical surface and a second optical surface that is orie in a precisely angular manner to an accurate angular position relative to the first surface optics. A set of molds for frontal curve is arranged in a regular arrangement, and a dosed amount of monomer mixture is deposited in each of the molds for frontal curve. It also has a set of molds for base curve in a regular arrangement. An arrangement of deposition tubes, placed on a support plate and coupled to a vacuum source, is used to collect and support the arrangement of the molds for base curve. Each of the deposition tubes relative to the support plate is then angularly rotated to a selected angularly orie position therein. The angularly orie arrangement of the molds for base curve is then assembled on the arrangement of the molds for frontal curve with the dosed amounts of monomer therebetween. The arrangement is such that each base curve mold is in a precisely angularly orie position relative to the front curve mold to produce a lens having first and second optical surfaces that are orie precisely angularly relative to one another. In greater detail, a set of molds for frontal curve in a regular arrangement in a support pallet for molds for frontal curve, and the set of molds for base curve in a regular arrangement in a mold support pallet is arranged. for base curve. A pallet placement system alternates the placement of the support pallets for the base curve molds with the support pallets for the front curve molds. The support plate and the arrangement of the deposition tubes alternate vertically between the positions of raised and lowered. In the lowered position, the arrangement of the deposition tubes is placed above the arrangement of the molds for the base curve, and each deposition tube receives and supports a mold for the base curve by a vacuum. Each arrange tube is mou angularly rotatably on the support plate, and an angular rotating mechanism common to each of the deposition tubes is coupled in the arrangement to angularly orient it to a precise angular position on the support plate. The common angular rotary mechanism is driven by a stepper motor which can be controlled programmatically to change the selected angularly orie position. The stepper motor drives movable zippers, which drive pinion gears mou around the deposition tubes. The regular arrangement includes a 2x4 arrangement, and each movable rack drives a 1x4 arrangement of deposition tubes, each of which is driven by a pinion gear placed around the mimes. Each base curve mold defines a toroidal surface, whose angular position is angularly orie with precision relative to the front curve mold to form a mold for a toroidal contact lens having a selected location of the cylindrical shaft therein.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing objects and advantages of the present invention for an arrangement with rotational orientation for deposition in base curves can be more readily understood by one skilled in the art with reference to the following detailed description of the various preferred embodiments thereof, taken in conjunction with the accompanying drawings in which the like elements are designated by identical reference numbers throughout all the views, and in which: Lae fig? rae Ka) -l (d) are schematic flow diagrams and illustrated a method for filling and assembling molds to produce contact lenses; Figure 1 (e) depicts a block flow diagram of a method for filling and assembling molds to produce contact lenses; Figure 2 is a top flat vieta of a conveyor pallet used to transport a set of contact lens molds to / from a filling and assembly station; Figure 3 is a cross-sectional view of an assembled mold as transported on the conveyor illustrated in Figure 2; Figure 4 is a schematic top plan view of a station for filling and assembly; Figure 5 is a schematic linear illustration of the time of the steps of assembling a mode as an example of a station for filling and assembling molds; Figure 6 is an exposure with toroidal orientation for the deposition in base curves according to the teachings of the present invention, and illustrates a mechanism for rack and pinion positioning to precisely control the position with angular orientation of each deposition tube in the same; Figure 7 is a vertical side view of a toroidal orientation arrangement for the deposition in base curves shown in Figure 6, and illustrates a row 1x4 of deposition tubes of a 2x4 arrangement of deposition tubes, and how the angular orientation position of each deposition tube in that row is controlled in common by the rack and pinion mechanism; and Figure 8 is a front vertical view of a toroidal orientation arrangement for deposition in base curves shown in Figures 6 and 7.

DETAILED DESCRIPTION OF THE DRAWINGS The rotationally oriented arrangement for deposition in base curves of the present invention is designed to operate in an environment for filling molds and assembling molds as described in detail in the US Patent Application Serial No. 08 / 431,635 regarding the Method and Apparatus for Filling and Assembling Molds for Contact Lenses, whose entire description is expressly incorporated herein by reference. The following explanation, with reference to Figures 1-5, is in the context of the explanation of the US Patent Application Serial No. 08 / 431,635, and is offered to explain the field of technology and the general background of this invention. The present invention is useful in a process for forming soft contact lenses from a monomer or polymerizable monomer mixture. The soft contact lenses are formed in a mold assembly consisting of a first mold half 31 for front curve and a second mold half 33 for a base curve, which can be assembled into a mold as illustrated in figure 3 The halves of the molds can preferably be formed of polystyrene which is transparent to visible and ultraviolet light. A centered curved section of the mold 31 for front curve defines a concave surface 31b, and a central curved section of the base curve 33 defines a convex surface 33b. The front curve 31 of the mold also defines a circular circumferential knife edge 31 (c), and an essentially uniplanar annular flange 31 (a) that is integral with the circumferential knife edge. The base curve of the mold also defines a substantially uniplanar rim 33). Each one of the halves 31 and 33 of the mold has a nape ear, respectively 3ld, 33d, projecting radially beyond the flange 31a, 33a, and serving to angularly align each half of the mold in a support vane, as illustrated in Figure 2. At least a portion of the surface 31b concave and the convex surface 33b has somewhat diminished dimensions in the frontal or base curves, respectively of a contact lens to be produced in the mold assembly, and are sufficiently smooth so that the surface of a contact lens formed by polymerization of a polymerizable composition in contact with the molding surface is optically acceptable. The mold is thin enough to transmit heat rapidly through it, and has sufficient rigidity to withstand the leverage forces applied to separate the mold halves when removing the molds. The monomer can be degaussed before pumping, as more particularly described in the North American Patent Application Series No., entitled "Method and Apparatus for Making Optical Lenses, assigned to the owner of the present invention. This procedure removes part of the dissolved gases present in the monomer mixture before pumping the monomer to the deposition or filling station. The discharge of the monomer from the nozzle in the middle of the front bend mold can optionally be done in vacuum to ensure that gases are not trapped between the rhino-wheel and the front mold for the lens while the nozzle is deposited. The complementary pair of first and second mold halves 31 and 33 that define the shape of the finally desired contact lenses are used to directly mold the mixture of rnonomers in which the mixture is dissolved in a non-aqueous solvent which replaces the water as it is described in US Patents Nos. 4,680,336, 4,889,664 and 5,039,459. After the deposition or dosing, in which the concave front half of the mold is essentially filled with a mixture 32 for initiation, the concave front half of the mold 31 is covered with a base half 33 of the vacuum mold to ensure that air bubbles are not trapped between the two halves. The first and second halves of the mold are then clamped in an assembly step to clamp any surplus monomer from the mold area and to properly align the mold halves by alignment of the mold flanges. Following the steps of assembling and securing the mold, the first and second halves of the mold are then clamped together for the second time in a precure step in which the polymerization mixture is exposed to the actinic light, preferably a lamp. ultraviolet, while the halves of the mold are clamped with clamps.

Characteristically, the mold halves are clamped for about 40 seconds with 30 seconds of actinic reaction. This irradiation with visible or ultraviolet actinic radiation produces a mixture of polymer and solvent in the form of the ultimately desired hydrogel lens. Upon completion of the precura step, the polymerization mixture has formed a partially polymerized gel, the polymerization being initiated through the entire mixture. Following the precuration step, the mixture of monomer and solvent is then cured in an ultraviolet ray oven in which the polymerization in the monomers is completed. After the polymerization process is completed, the two halves of the mold are separated in the removal step of the molds leaving the contact lenses in the middle of the mold for the first or frontal curve from which it is subsequently removed. The mold halves are used characteristically for front and base curve for a single molding operation and then removed or disposed of. After the removal of the mold * the solvent is displaced with water to produce a hydrated lens which when fully hydrated and regulated in pH is in the final shape and size of the lens. In most cases, this is nominally 10 * larger than the original molded polymer and solvent article. The polymerization of the polymerizable composition in the mold assembly is preferably carried out by arranging the composition at the polymerization starting conditions. The preferred technique is to include initiators in the composition that influence exposure to ultraviolet or visible radiation; and exposing the composition to ultraviolet or visible radiation of effective intensity and duration to initiate the polymerization and allow it to proceed. For this reason, the mold halves are preferably transparent to ultraviolet or visible radiation. After the precursor step, the monomer is again exposed to ultraviolet or visible radiation in a cure step in which the polymerization is allowed to proceed to completion. The required duration of the remainder of the reaction can easily be determined experimentally for any polymerizable composition. After the polymerizable composition has been polymerized, the mold assembly is assembled to allow the subsequent processing of the polymerized product to form a contact lens (including in each procedure for example the washing and hydration, the packaging and the sterilization of the lens). Preferably, the flanges of the front and base halves of the mold are made and removed from each other, either in directly opposite directions or through an angle in a lever movement. Advantageously, the assembly is heated first moderately to facilitate separation of the polymerized article from the surfaces of the mold halves.

Figure 1 (e) is a block flow diagram of the method of operation and Figures Ka) - (d) are schematic illustrations of the method of operation. As illustrated in FIG. 1 (a), the specialized pallets 30 are fed to the deposition stations and can be transported, in alternate pallets, the mold halves for the front curve and the mold halves for the bases or the base curve. Figure 2 illustrates a pallet for mold support for front curve that conveys a 2x4 arrangement of the assembled molds for front and base curve as shown in figure 3. As will be described in more detail with respect to figure 4, the pallets arrive at a filling and assembly station in alternating sequence with the pallet containing the halves for first base curve in sequence, followed immediately after by a pallet loaded with the mold halves for front curve, and etc. These pallets are transported to the filling and mold assembly station sequentially at the speed of approximately one pallet every 6 seconds. As illustrated in Figure Ka), a predetermined amount of the polymerizable hydrogel or monomer 10 is deposited in a mold half for front curve by means of a nozzle 142 for precision dosing, which is part of the dosing station 50 or fill. The monomer can be dosed under vacuum in each of the halves of the front curve mold, transported in the alternating vanes, to avoid the possibility of trapping any gases between the bottom and the half 31 of the front curve mold. In addition, the polymerizable monomer mixture can be degassed to ensure that no significant dissolved gases are present in the monomer as the dissolved gases may well form bubbles while the monomer is exposed to the vacuum conditions. In a preferred embodiment, precisely 60 μl of hydrogel or polymerizable monomer is deposited in each half of the front curve mold to ensure that the cavity of the mold is overflowed, in order to avoid the possibility of incomplete molding. Excess monomer is removed from the mold cavity in the final assembly of the mold halves for front and base curve, as will be described below. The second station in the apparatus for depositing and assembling the mold parts is a stamping station illustrated schematically in Fig. Kb), and is described in more detail in the North American Patent Application Series No., entitled "Method and Apparatus for Apply a Surfactant to Surfaces for Molding, also assigned to the owner of the present invention. As illustrated in Fig. Kb), the annular ear 31a surrounding the mold half for front curve is stamped by means of the embossing pad 21 with a thin film of surfactant which has been found to be useful for removing the inonornero in excess displaced from the mold cavity at the time of assembly. The excess overanery (when using hydroxyethylmethacrylate, is called "HEMA") moves between the ears 31 (a) and 33 (a), as illustrated in Figure Kb) to form a ring 34 of the HEMO in excess of the moment of the assembly of the mold, as shown in figure 3. This HEMA ring is also cured contemporaneously with the polimerizable hydrogel which forms the contact lens 32. By means of stamping the ear 31 (a) of the front curve mold with a mold release surfactant, the HEMA ring 34 is preferably adhered to the ear 33 (a) of the mold half for bath curve and Removes from the production line at the moment that moves half of the mold for the base curve in the deseneamble of the mold. In a preferred embodiment, the mold release surfactant is a polyethylene oxide sorbital monooleate, commercially sold by the factory name "Tween 80". Station 60 with printing head mounted on it a set of stamping 21, each of which is adapted to be moved in a reciprocal vertical movement in a coordinated manner by the pistons 22 mounted in the stamping head station 60, in which the number of stampers 21 correlates with the number of frontal curves 31 carried by the palette 30 of the mold. A hopzontally interchangeable stamper member (not shown) is adapted to be placed in separate relation below the lower end of each stamper 21 when the stamper is in the raised position, and is constituted of a suitable porous material, such as porous polyethylene having An average size per pore of 10 microns, which is impregnated with a solution containing a surfactant agent, the latter being present in a highly concentrated state. The upper surface of the pad member is covered by a filter, preferably nylon, having a mesh size of 1.2 microns so that it acts as a dosing artifact and allows only a relatively small amount of the surfactant to pass therethrough when the The surfactant is absorbed as a wick from the bottom of the pad member to the top when the pad member is pressed by the lower ends of the die heads 21. The method of operation of the assembly station will now be described with respect to FIGS. 1 (c), Kd) 4 and 5. According to the pallets 30 containing lae rmtadee 30 of the bath curve mold, which are the first in the alternating sequence, enter the assembly station illustrated in Figure 4, a set of alternating vacuum-clamping pistons or deposition tube 71 is reciprocated downward to receive the mold halves for the base curve of the first dß the alternating paddles 30. The mold halves for the base curve are lifted by means of a vacuum extracted in the chamber 71 (a), which secures each half of the base curve mold to an alternating piston or deposition tubes 31. After receipt of the base curve, the empty pallet 30 is advanced for the base curve, and a second pallet containing the mold halves for front curve and the rnonomer below the alternating piston is advanced, as illustrated in FIG. figure Kd). A vacuum is then drawn around the entire assembly to ensure that gases are not trapped between the mold halves and the rnonomer at the time the mold is assembled. After receipt of the base curve, the toroidal orientation arrangement for base curve deposition of the present invention is used, as shown in Fig. 6-8, to orient the deposition tubes in a precise angular orientation of the axis of the cylindrical or toroidal surface of the mold base curve. The piston 70 is then driven alternating downwards so that the curve 33 of the base curve mold contacts the monomer and moves it through the mold cavity. Optionally, the alternating action of the piston can be lowered enough to seat the flat annular surface 33 (a) of the half 33 of the curve mold base d against the circumferential knife edge 31 (c) of the mold half for the front curve , thereby aligning the parts of the mold and displacing the excess monomer in the space between the ears 3Ka), 33 (a) in whose forms the HEMA ring 34 is to be formed in excess. The half of the mold for the base curve can then be clamped to the mold half for the front curve by means of a fluctuating overtravel mechanism. After a predetermined period, the vacuum in the chamber 71 (a) is suspended, but the pressure is retained by the clamping of the piston 71 during the overtravel of the assembly module. The vacuum surrounding the assembled halves of the mold and the alternating piston 71 is then suspended, and the alternating piston 71 is retracted., thereby allowing pallet 30 to be transferred out of the assembly station to the precura station. The assembly of the mold halves according to a modality disclosed as an example is described in the sequence chart of the time illustrated in Figure 5 in which the position of an alternating piston or deposition tube 71 is plotted. function of time. As illustrated in Figure 7, at the zero starting point, the alternating paint 71 starts to descend for the receipt of the base curve, and reaches and secures the base curve in approximately 0.25 seconds. The piston 70 then alternates upward to its upper position 14 millimeters above the pallet 30 in approximately 0.25 seconds. After receipt of the baee curve, disposition 80 with toroidal orientation for deposition in base curves, Figures 6-8, of the present invention is used to orient each of the deposition tubes to a precise angular orientation of the ee. of the cylindrical or toroidal surface of the mold base curve. The pallets are then advanced, whereby the pallet is removed from the mold half for the base curve and the pallet of the mold half for the front curve is inserted, transfer requiring approximately 0.5 seconds. While the pallets are being transferred, the vacuum chamber begins its descending towards the pallet 30 of the front bend mold and makes contact with the mold pallet to secure a seal between the chamber and the pallet. A seal will be established at approximately 1.25 seconds after point 0, and the nitrogen is then evacuated in the chamber until a vacuum equilibrium is reached in approximately 1.75 seconds. It should be noted that the alternating flange or deposition tube 71 is carried inside the vacuum chamber as the vacuum chamber deepens and the vane, the alternating flange 71 and the half 33 of the curve mold have been lowered. partially about 5 millimeters above the mold half for front curve. At 1.75 seconds, the alternating piston 71 starts the independent down stroke and makes contact with the monomer at approximately 2.5 seconds after point 0. The downward stroke of the alternating paint continues and at approximately 3 seconds, the mold half is firmly seated. for base curve on the dividing edge 31 (c) of the mold half for frontal curve indicating the formal assembly. Shortly thereafter, the vacuum in chamber 71 (a) is interrupted, but the alternating piston 71 maintains a downward force on the mold half for the baee curve while the rest of the assembly module continues a downward stroke to establish a separate fluctuating anchorage. with half mold clamp for base curve against a front curve. Approximately at 3.4 seconds, the vacuum in the vacuum chamber is suspended, and at approximately 4.4 seconds the alternating piston 71, the vacuum chamber and the assembly module begin to retract. At 4.75 seconds, the pallet containing the halves of the assembled mold is transferred out of the bundle assembly, and a new pallet containing the mold halves for the base curve is inserted under the mold assembly module. Approximately after 5 seconds, the alternating piston 71 is moved to its position of receipt of the base curve, and after 6 seconds, the assembly starts again at the starting point 0. The filling and assembly arrangement of the horizontal projection mold in Figure 4 in which a conveyor 20 provides a sequenced supply of alternating pallets, two of which are illustrated schematically in Figure 4 as 30 (a) and 30 (b). In an exemplary embodiment, the pallet 30 (a) contains 8 parts of the mold for baye curve in a 2x4 arrangement and the pallet 30 (b) contains 8 parts of the mold for the front curve in a 2x4 arrangement.

These vanes travel over a conveyor 20 in a nitrogen tunnel 12 that surrounds each of the conveyors and artifacts for material handling to provide low oxygen environment for all the antee parts of the polymerization. . The impellers 13 and 14 of the pallet for material handling direct the pallets of the conveyor belt 20 to the filling and assembly station 15, which is also enclosed within the nitrogen environment 16. The environment 16 can be alternated to serve by means of the handle 17 and the hinges 18. Within the filling and assembly station 15, a filling or dosing assembly 50 is provided to fill the front curves with a dose of precision predetermined monomer, an apparatus 60 for applying the casting surfactant of the mold to the ear area of the molds for frontal curve, and to station 70 for the assembly of the mold. After the assembly, the empty pallets of the base curve mold are returned by an impeller 19 for material handling to the conveyor 22 for the return of the pallet for baee curve, while the assembled and assembled mold assemblies are transported in their respective pallet by means of the conveyor 21 to the precura station. The material handling apparatus 14 is a precision artifact that drives the vanes one at a time on the path 22 to be processed by the various stations in the deposition and assembly apparatus. The pallets are advanced in series, the advance stroke being the width of the pallet ≥ or less than 0.1 millimeters. This makes it possible to place the pallets for their precision correspondence in the various modules of the filling and assembly station 15. The detailed description of the invention has now involved a description of known apparatuses and procedures to make possible an appreciation of the present invention illustrated in Figures 6, 7 and 8. Figure 6 is a sectional view of an arrangement 80 with toroidal orientation for the base curvature deposition according to the present invention, and illustrates a rack and pinion positioning mechanism to precisely control the angular orientation position therein. Figures 7 and 8 are the vertical side and front vietae of the disposition 80 with toroidal orientation for deposition in base curves shown in Figure 6. The arrangement 80 with toroidal orientation for the curvature depoeition of baee includes a 2x4 die the depopulation tubes 71, placed on a support plate 84 and coupled to a vacuum source, which are used to receive and support the arrangement of the molds 33 for base curve. The support plate 84 and the arrangement of the deposition tubes 71 are placed above the arrangement of the molds 73 for the baee curve, and each deposition tube receives and supports a mold for the base curve by means of a vacuum. Each deposition tube 71 preferably includes a contact head 82 for base curve having an alignment groove 83 therein which aligns itself with a corresponding projection on the base curve mold to ensure a self-aligning fit. between them. Each of the deposition tubes 82 is then rotated angularly relative to the support plate in a bearing 86 to a selected angularly oriented position in the ism. The angularly oriented arrangement of the base curve mold is then assembled on the arrangement of the front molds with the dosed quantities of the monomer therebetween. A common angular rotating mechanism is coupled to each of the deposition tubes in the arrangement to angularly orient each of the deposition tubes to the precise angular position on the support plate. The common angular rotary mechanism is actuated by a stepper motor 88 which can be controlled programmatically to change the selected angular orientation position. Stepper motor drives a 90-in-T bar that drives two movable zippers 92, and each of the deposition tubes 71 includes a pinion 94 around them that is driven by a rack. The regular deposition includes a 2x4 arrangement, and each movable rack 92 drives a 1x4 arrangement of the deposition tubes 71, each of which is driven by a pinion 94 placed around them. Each mold 33 for base curve defines a toroidal surface, whose angular position is angularly oriented with precision with respect to the mold 31 for front curve to form a mold assembly, Figure 3, for a toroidal contact lens having a selected axis placement cylindrical the same. The present invention differs from a normal molding operation according to the prior art in that the toroidal molds for base curves are oriented or rotated from the neutral casting on the base curve structure at a pre-written angle before the force It will control the shape of the mold for front and bottom curve by means of the assembly. The toroidal orientation arrangement 80 for deposition in base curves directs the mold 33 for base curve to a precise angular position and then assembles it to the mold 31 for front curve in one step. By altering the motor controls 88 step by step, the precise angle of the rotation of the base curve can be easily adjusted. You can easily adjust the speed and strength with which the base curve and the front curve are assembled. In one embodiment, the force of the base curve to the front curve assembly is developed by deflecting the spring loaded deposition tubes. Referring to Fig. 6-8, the toroidal orientation arrangement 80 for deposition in base curves consists of a 2x4 arrangement of deposition units, each of which includes a deposition pipe 71, a compression spring 96 and a fitter 98 micrometer type preloaded with spring. The disposition 80 with toroidal orientation for deposition in curves of baee also includes a plate 84 for supporting the deposition arrangement, a mechanism T-bar 90 connecting the two driving racks 92, the pinions 94 of the tubes, the step rnotor step and the screw 88 connected to the mechanism T-bar 90. The provision with toroidal orientation for the deposition in base curves operates as follows: POSO 1. The artifact 80 is lowered to a facility for cutting the base curve ( a support vane for the base curve) by a motor drive coupling 102 step by step guided by the shaft bearings 104 and the vertical shafts 106. STEP 2. Before the baee curves are cut, a vacuum source is operated which travels through the vacuum manifold 108 of the layout plate and then through the flexible pipe 110 to the end of the tube 71 of deposition where the base curve is located. The artifact 80 is then retracted upwards with the base curves fixed to the depoeition tube. STEP 3. After the artifact 80 is retracted to the upward position, the tubes 71 are deflected and oriented at a programmed angle by moving the stepping motor and the screw 88 by means of the mechanism 90 of the T-bar. , the driving zips 92 and the piñonee 94 of the tubes. STEP 4. The artifact 80 was then controlled in a controlled manner by the stepper motor 101 and the mechanism 102 on the dosed installation of the front curve. After physical contact is made with the knife edge 31 (c) of the front curve, the motor 101 step by step and the mechanism 102 accelerates the base curve at a higher speed further into the cavity until the amount The supercharging on the plate of the arrangement has caused the desired force of the assembly to be developed by the compression spring 96. The vacuum of a timed operation is deactivated just before the curve of base make contact with the knife edge of the front curve. The free rotary movement of the deposition tube 31 on the support plate 84 is aided by the bearings 86 coated on the tubes. The tension point of this method is determined by the relative position of the support plate 84 of the arrangement which is driven by the stepper motor 101 and the mechanism 102. The assembly force of the base curve to the knife edge of the front curve ee determined by two machine adjusters. First, the micrometer type winders 98 with reloading reload determine the force required to begin the relative movement between the deposition tube and the plate of the arrangement and which equally causes an arithmetic change in force for a given overtravel. Secondly, the amount of overrun programmed into the paeo a paeo engine mechanism determines the final assembly or the value of the seating force. STEP 5. Layout 80 is retracted to its upper position. Once there, the depoeition tubes 71 are oriented with bases originally or initial positions by the stepper motor movement and the screw 88 by means of the T-bar 90, the drive racks 92 and the loe pinions 94. tubes The operation is then recycled with step 1. The arrangement 80 for deposition in toroidal base curves has several unique features. The use of the disposition 80 for the deposition in a filling and assembly machine with the sequence of operations discussed above will assemble front curves and frontal curvatures with angular orientation prescribed in one step. The common assembly artifact can not rotate the molds for base curve at any point. A common assembly or deposition is a two-step procedure in which the mold for the base curve is dropped over the metered cavity and moved to another complete station to continue being assembled by a weight-free system. The common procedure of two paeoe does not result in making toroidal lenses of precision because once the base curve is allowed to float over the dosed cavity before the free weights, it is free to change its angular poem. This is not compatible with the required angular accuracy of a molded toroidal contact lens. In this way, the present invention takes into account the prestressing eneamble of the toroidal lens molds at any clinically desirable angle using the technology and molding machinery for soft lenses currently available. The provision provided with springs for the deposition in base curves is totally integrated to the present invention, thereby allowing an enearnble or deposition of a single step combined with the toroidal orientation in base curves. In a preferred alternative embodiment, each compression spring 96 and pre-charged micrometer spring type micrometer can be replaced by a pneumatic piston and a cylinder drive member. The rotational orientation arrangement 80 for the deposition in base curves of the present invention can be used in a vacuum environment for mold filling as described in US Patent Application No. 08/431, 635 for a Method and Apparatus for Filling and Assembling Molds for Contact Lenses, presented on May 1, 1995. Alternatively, a toroidal orientation arrangement can be used for deposition in base curves in an atmospheric environment (not vacuum) for the filling of molds. The present invention preferably uses an arrangement for filling contact lens molds in a single step or is described in US Patent Application No. 08 / 431,635, in contrast to an arrangement for molding according to the prior art in which the base curve is placed on a portion of monomer deposited in a front curve, and is more or less free to rotate before a secure anchorage of the base curve to the front curve, as described for example in the US Patent No ., 564, 348. The described embodiment rotates the molds for base curves of contact lenses (which generally define the toroidal surface) with respect to the molds for frontal curves of contact lenses. However, the relative angular rotation achieved by the present invention could also be effected by rotating the front curves of the contact lenses with respect to the base curves of the contact lenses. Alternatively, the toroidal surfaces of the frontal curves could be placed, although basic curves are preferred. In addition, the rack and pinion mechanisms can be replaced by alternative mechanisms, such as a mechanism that uses a time-regulating band or a direct drive motor on each tube of depoetion. In the die-filling for the application of US Patent No. 08 / 431,635, after securing the base curves to the frontal curves, the assembled molds are moved or oriented to another work station for curing the resin of monomer by exposure to actinic ultraviolet radiation. However, the present invention could also be used in the dispensing of the mold stations in which the monomer resin is cured by disposition to the actinic wording in the work setting in which the front and base curves are assembled. The present invention can carry out "on the fly" changes in the position of the toroidal axis on the contact lens, since such changes involve merely programming the stepper motor 88 to rotate the base curves to a different angular position for the next molding sequence. An embodiment disclosed uses an arrangement in which a 2x4 arrangement of interconnected base curves, interconnected by sliding pieces, is placed on an installation for cutting base curves that separates (cuts with die) the sliding pieces to produce a 2x4 die-off of individual unconnected baffles, each of which is rotated to an angular pore selected by the toroidal orientation arrangement for deposition in base curves of the present invention. However, the present invention can also be used in molding arrangements in which an individual baffle arrangement is supported in a molding vane having an arrangement of support cavities, each of which supports and places a curve of base. While various embodiments and variations of the present invention are described in detail therein for a rotating orientation arrangement for deposition in base curves, it will be apparent that the description and teachings of the present invention will suggest many alternative designs for the experts in the art.

Claims (23)

NOVELTY OF THE INVENTION CLAIMS

1. - A method for producing a molded lens having a first optical surface and a second optical surface that is angularly oriented with precision to a precise angular position with respect to the first optical surface consisting of: a) arranging a set of molds for front curve in a regular arrangement; b) deposit a dosed amount of monomer mixture in each of the set of molds for frontal curve; c) arranging a set of molds for a base curve in a regular arrangement; d) use a diepoeition of depoeition tube, placed on a support plate and coupled to a vacuum source, to receive and support the arrangement of the molds for base curve; e) angularly rotating each of the deposition tubes relative to the support plate to a selected position angularly oriented therein; f) placing the angularly oriented arrangement of the base curve molds on the arrangement of the front curve molds with the dosed amount of the monomer therebetween, so that each base curve mold is in an angularly oriented position with precision with respect to a mold for front curve to produce a lens having first and second optical surfaces that are angularly oriented with precision with respect to each other.

2. A method co or claimed in the claim 1, characterized in that a set of molds for frontal curves is arranged in a regular die in a pallet of eoporte of the molds for frontal curves.

3. A method as claimed in the claim 2, characterized in that a set of molds is provided for base curves in a regular arrangement in a mold support vane for baee curves.

4. A method as claimed in the claim 3, characterized in that the palettes of support of the mold are alternating for curve of baee in correspondence with the pallets of support the molds for frontal curves in a pallet correspondence system.

5. A method as claimed in the claim 1, in which the support plate is alternated vertically and the replacement tubes placed therein between the up and down positions are alternated, and in the lowered position, the disposition of the tubes of deposition is placed above the disposition of the molds for base curves, and each deposition tube receives and supports through a vacuum a mold for base curves, and each deposition tube is mounted in an angularly rotating manner on the support plate, and an angular rotating mechanism is engaged common to each of the deposition tubes in the arrangements for angularly orienting each of the deposition tubes to a precise angular position on the support plate.

6. A method co or claimed in the claim 5, in which? N common angular rotating mechanism is driven by a stepper motor.

7. A method as claimed in the claim 6, further characterized in that the stepper motor is controlled by a program to change the selected position angularly oriented.

8. A method as claimed in claim 6, further characterized in that the stepper motor drives movable zippers and the deposition pipes include sprockets driven by the movable zippers.

9. A method as claimed in the claim 8, further characterized in that the regular arrangement includes a 2x4 deposition, and each movable rack drives a 1x4 arrangement of the deposition tubes driven by a pinion coupled to each deposition tube.

10. A method as claimed in claim 1, characterized in that each mold for curve dß baee defines a toroidal surface, whose angular position is angularly oriented with precision with respect to a mold for frontal curves to form a mold for a toroidal lens .

11. An apparatus for producing a molded lens having a first optical surface and a second optical surface that is angularly oriented with precision to a precise angular position with respect to the first optical surface, consisting of: a) a pallet of support for frontal curves to support a set of molds for frontal curves in a regular arrangement; b) a deposition means for depositing a doped amount of the monomer mixture in each of the set of the molds for frontalee curves; c) means for supporting a mold assembly for bale curl in a regular arrangement; d) a support plate for rotatably supporting an arrangement of deposition tubes that are coupled to a vacuum source to collect and support the die deposition of the molds for base curves; e) means for angularly rotating each of the deposition tubes relative to the support plate to an elective pointer oriented angularly on the support plate; and f) a dungeon eetation to place the arrangement of the angularly oriented molds for base curves on the arrangement of the molds for frontal curves with the dosed amount of the monomer therebetween, so that each mold for base curves is in a position angularly oriented with respect to a mold for frontal curves to produce a lens having first and second optical surfaces that are angularly oriented with precision with respect to each other.

12. Apparatus as claimed in claim 11, further characterized in that a set of curves for baff curve is arranged in a regular arrangement in a mold support vane for base curves.

13. Apparatus as claimed in the claim 12, further characterized in that a pallet matching system alternates the matching of the mold support pallets for base curves with the mold support blades for front curves.

14. Apparatus as claimed in claim 11, which further includes a scan or vertical for vertically alternating the sop plate. orte and the disposition of the deposition tubes placed therein between the up and down positions, and in the lowered position, the arrangement of depoeition tubes is placed above the arrangement of the molds for baee curves, and each tube of The deposition receives and supports a mold for base curves by means of a vacuum, and each deposition tube is mounted in an angularly rotating manner on a support plate, and an angular rotating mechanism common to each of the deposition tubes is attached to the base. the arrangement for angular orientation between each of the deposition tubes at an angular position selected on the support plate.

15. Apparatus as claimed in the claim 14, further characterized in that the common angular rotary mechanism includes a stepper motor.

16. Apparatus as claimed in the claim 15, further characterized in that the stepper motor is controlled by a program to change the selected position angularly oriented.

17. Apparatus as claimed in claim 16, further characterized in that the stepper motor drives movable zippers and the deposition tubes include sprockets driven by the mobile zippers.

18. Apparatus as claimed in the claim 12, further characterized in that each mold support vane for front curves sop > orta a 2x4 arrangement of molds for frontal curves, each mold support vane for base curves supports a 2x4 arrangement of the molds for base curvature, and each movable rack imputes a 1x4 arrangement of the deposition tubes driven by piñonee coupled to the winter.

19. Apparatus as claimed in claim 11, further characterized in that the molds for toroidal base curves are rotationally oriented from a neutral position defined by a molded structure for base curves to a selected angle before assembling the molds for curves front and base.

20. Apparatus as claimed in claim 12, further characterized in that the trodalee molds for base curves are rotatably oriented to a neutral position defined by a support vane of the mold for base curves at a selected angle prior to assembly of the mold. the molds for frontal and base curves.

21. Apparatus as claimed in the claim 11, further characterized in that each tube dβ deposited in the disposition of the deposition tubes is supported by a pneumatic piston and a cylinder driving element.

22. Apparatus as claimed in claim 11, further characterized in that the support plate and the arrangement of the deposition tubes placed therein alternate vertically between the up and down positions.

23. Apparatus as claimed in claim 11, further characterized in that the apparatus assembles toroidal base curves and front curves with a prescribed angular orientation in a one-step assembly operation. SUMMARY OF THE INVENTION A rotating orientation arrangement for deposition in base curves to assemble base curves and front bends of contact lenses with a prescribed and programmable angular orientation to produce a contact lens having a selected placement of the axis in the same, such as a toroidal shaft for a toroidal contact lens. A mold arrangement is provided for front curves in a support pallet with a dosed amount of the monomer mixture deposited in each of the molds for frontal curves. A disposable tube arrangement is used, placed on a support plate and coupled to a vacuum source to receive and support a mold deposition for baee curve. Each of the deposition tubes is then angularly rotated on the support plate to a selected angularly oriented position therein. The common angular rotary mechanism is coupled to each of the deposition tubes in the arrangement to angularly orient each of the deposition tubes to an accurate angular position in the support plate. The common angular rotary mechanism is driven by a stepper motor which can be controlled programmatically to change the selected angularly oriented position. The stepper motor drives movable zippers, which impel pinions around the deposition tubes. The angularly oriented die-casting is then assembled for baye curves on the mold arrangement for rubbing to produce toroidal lenses having first and second optical surfaces that are angularly oriented with precision one respect to another. GC / ieoh * P96 / 907