Patent ID: 12186917

DETAILED DESCRIPTION

FIG.1illustrates the remote gripper calibration tool1which includes an assembly plate10to which a master gripper30is mounted (the master gripper30is shown in more detail inFIGS.3-4). By “remote” it is meant that the calibration tool is not part of a lens manufacturing line but is instead located separately so that the calibration of the lens gripper may take place without disruption to the manufacturing process and prior to the time the lens gripper is required for use. The remote gripper calibration tool1also includes at least a Z-directional position sensor12(see detail A as shown inFIG.2). The Z-directional position sensor12is desirably a non-contact sensor and may be, for example, a laser detection system capable of determining position based on the amount of light occluded, which is fixedly mounted to the remote gripper calibration tool1.

In some aspects, the remote gripper calibration tool1may also desirably include an X-directional position sensor14and a Y-directional position sensor16as shown inFIG.2, which like Z-directional position sensor12may be non-contact sensors such as the mentioned laser detection system. For the sake of clarity,FIG.2also includes a positional diagram illustrating the Z-direction (up/down, i.e., vertical), Y-direction (left-right horizontal as the figure is viewed) and X-direction (into and out of the diagram as the figure is viewed).

In use with the master gripper30, to calibrate a lens gripper, first the master gripper30is mounted to the assembly plate10of the remote gripper calibration tool1and the Z-directional position sensor12is used to determine the Z-directional (vertical) position of the tip of the master gripper30.FIGS.3-4illustrate the master gripper30in more detail, including the tip32of the master gripper. The master gripper30has a length extension terminating in the tip32so as to match a predetermined desired final extension length of a lens gripper which is to be calibrated. The master gripper30also has mounting portions34,36which lie flush against the assembly plate10when the master gripper30is mounted thereto, and contain fastening elements38which may be for example a bolt or captive screw (additional fastening elements of mounting portions34,36are not shown). The mounting portions and fastening elements of the master gripper30as well as centering bolts (not shown) projecting from the surface of the mounting portions34,36towards the assembly plate10and fitting into corresponding centering holes in the assembly plate10are configured to match those of an actual lens gripper (to make sure the master gripper30and the lens grippers to be calibrated are reproducibly mounted to the assembly plate).

Returning toFIGS.1-2, the master gripper30is shown mounted to the assembly plate10, with the tip32of the master gripper30extending into the portion of the remote gripper calibration tool1including the Z-directional position sensor12to measure the Z-directional position of the tip32of the master gripper30. As mentioned, X- and Y-directional position sensors14and16may also be provided and if so, are used to measure or determine the X- and Y-position of the tip32of the master gripper30. After the desired position information regarding the tip32of the master gripper30has been collected (at least Z-directional position and possibly also X- and Y-directional position information), the master gripper30is unmounted from the remote gripper calibration tool1.

A lens gripper40is shown inFIG.5. As shown, the lens gripper40has a tip42which engages and picks up a contact lens from a receptacle. Lens gripper40also includes a handle44for assistance in managing the mass of the lens gripper40during mounting and unmounting operations. As shown inFIG.5, the lens gripper40is set with its tip42in the lowermost position or its final extension length. In operation, the tip42of the lens gripper40is raised and lowered along the pneumatic cylinder46to remove a contact lens from its receptacle; that is, in its lowermost position the tip42of the lens gripper40inserts into a receptacle to collect the lens then is raised along the pneumatic cylinder46to extract the lens from the receptacle.

As shown inFIG.6, after the tip32position(s) of the master gripper30have been determined and the master gripper30is unmounted, the lens gripper40to be calibrated is mounted to the assembly plate10of the remote gripper calibration tool1. While not shown inFIG.6, as mentioned above the master gripper30and the lens gripper40generally have the same type of mounting portions and fastening elements, to achieve the same fit to assembly plate10. Using the Z-directional position information obtained when the master gripper30was mounted onto the remote gripper calibration tool1, it can be determined using the Z-directional position sensor12whether the tip42of the lens gripper40matches the predetermined desired final extension length, which as mentioned above was determined using the master gripper30, or is within an acceptable distance of the determined Z-directional position of the tip32of the master gripper30. Generally speaking, the tip42of the lens gripper40should be within about 300 microns (plus or minus) of the determined Z-directional position of the tip32of the master gripper30. If the tip42of the lens gripper40is not within an acceptable Z-directional distance, the final extension length of the tip42of the lens gripper40is adjusted to match the predetermined final extension length or to be within the acceptable distance.

In other aspects, if the X-directional position sensor14and a Y-directional position sensor16are provided, it can be determined whether the tip42of the lens gripper40matches (or is within an acceptable distance of) the X- and Y-position information collected when the master gripper30was mounted to the assembly plate10of the remote gripper calibration tool1. If the tip42does not match the X- and/or Y-position information collected using the master gripper30, e.g. tip42is not centered or is tilted at an angle from vertical, this could indicate that the lens gripper40is not fully mounted to the assembly plate10or in need of additional adjustment, or that it had been improperly manufactured, and that another lens gripper need be selected. Once a given gripper has undergone the calibration process, it can be stored away until it is needed to rapidly replace another lens gripper on the lens manufacturing line.

In addition, as shown inFIG.6, in still other aspects the remote gripper calibration tool1may be provided with additional features, such as a vacuum connector20and a pneumatic pressure connector22which may be connected to the lens gripper40via the respective vacuum coupling24and pneumatic pressure coupling26of the lens gripper40, and used to test for proper vacuum and pressure function of the lens gripper40. Moreover, the remote gripper calibration tool1may be provided with one or more electrical connectors (not shown) which may be connected to corresponding electrical connectors of the lens gripper40to test proper function of the electrical connectors for operating the control valves of the lens gripper40enabling the supply of vacuum or pressure.

FIGS.7-11illustrate still a further aspect of the invention.FIGS.7-8show a lens receptacle carrier plate50in perspective and edge-view, respectively. The lens receptacle carrier plate50is part of a lens receptacle transport system and may be a plate for carrying various types of lens-containing receptacles during contact lens manufacturing. For example, the lens receptacle carrier plate50may be configured to and used to carry lens inspection cuvettes, lens mold halves, lens blister packages, or other receptacles used to hold contact lenses at various points in a manufacturing line. For use in calibrating lens grippers, no lens receptacles are placed on the lens receptacle carrier plate50and instead an adapter52is mounted thereon. The adapter52includes a plurality of raised target studs54with an upper surface56, as shown inFIGS.7-8.

In this further aspect of the invention, the master gripper30is utilized temporarily on the actual lens manufacturing line. It should be noted that in the practice of this further aspect of the invention, it does not matter whether the master gripper30is first mounted to the assembly plate10of the remote gripper calibration tool1to have the positioning of the tip32of the master gripper30determined, or whether the master gripper30is first utilized in this further aspect on the lens manufacturing line. In use, the master gripper30is mounted to a gripper mounting plate on the lens manufacturing line. Generally such a gripper mounting plate includes a plurality of positions for lens grippers, for example seven, eight, ten, twelve, fourteen, sixteen, eighteen, twenty or more. The master gripper30is mounted to a first position on the gripper mounting plate and in the practice of this further aspect of the invention, the lens receptacle carrier plate50including the adapter52is transported in the manufacturing line below the master gripper30.

This is shown inFIG.9with the master gripper30positioned above the lens receptacle carrier plate50and in particular the tip32of the master gripper30is position directly above the upper surface56of one of the target studs54. Turning to detail B ofFIG.9as shown inFIG.11, it can be seen that a small gap or distance exists between the tip32of the master gripper30and the upper surface56of the target stud54(the gap as indicated by the converging arrows), such that the tip32of the master gripper30does not contact the upper surface56of the target stud54. This distance corresponds to a desired predetermined distance and is configured to be small enough to permit a lens gripper to acquire the contact lens from a receptacle, but not so small that the tip42of the lens gripper presses the lens against the bottom of the receptacle, which could cause damage to the contact lens.

Generally speaking, a suitable gap or distance between the tip32of the master gripper30and the upper surface56of the target stud54may be between about 400 microns and about 1000 microns, and may particularly be about 700 microns. The distance may be measured and set using known tools such as finely machined metal feeler or gapping gauge, or by use of laser measurement devices or other optical measurement devices such as are known to those of skill in the art.

Once the measurement of the distance between the tip32of the master gripper30and the upper surface56of the target stud54has been taken, if the distance is not as desired, the gripper mounting plate may be adjusted upwards or downwards to correct the distance. Then, the master gripper30is mounted to at least one, second position on the gripper mounting plate (or a second essentially identical master gripper30is used) and the process of measuring the gap or distance, and adjusting the gripper mounting plate if necessary, is repeated to ensure that the distance is the same across the gripper mounting plate as between the tip32of the master gripper30and the upper surface56of the target stud54for each position so tested. Normally the positions for mounting the master gripper30to the gripper mounting plate will be the first and last of the plurality of positions, but this is not required as long as sufficient distance exists between positions to ensure reliable result.

FIG.10shows the lens gripper40mounted on the gripper mounting plate and the lens receptacle carrier plate50holding lens inspection cuvette60. As shown inFIG.10, the tip of the lens gripper40is not visible because it is inserted inside the lens inspection cuvette60in order to grip the contact lenses (not shown).FIGS.9-10are on the same level and it can be seen that in the case of the lens receptacle carrier plate50carrying the lens inspection cuvettes60, the cuvettes are configured and mounted such that the cuvette bottoms are arranged to be at a level that corresponds to the level of the upper surfaces56of the target studs54when the adapter plate52was mounted to the lens receptacle carrier plate50.

Various other aspects are of course possible. If the lens receptacle carrier plate50is configured to carry mold halves as mentioned above, then each of the mold halves has a surface holding a contact lens to be gripped by a lens gripper, and so the mold halves are arranged on the lens receptacle carrier plate50with the surface arranged to be at a level that corresponds to the level of the upper surfaces56of the target studs54when the adapter plate52was mounted to the lens receptacle carrier plate50. Similarly, if the lens receptacle carrier plate50is configured to carry lens blister packages as also mentioned above, then each of the blister packages has a surface holding a contact lens to be gripped by a lens gripper (or a surface upon which a contact lens is to be deposited by a lens gripper), and so the blister packages are arranged on the lens receptacle carrier plate50with such surface arranged to be at a level that corresponds to the level of the upper surfaces56of the target studs54when the adapter plate52was mounted to the lens receptacle carrier plate50.

While various aspects of the invention have been described with the aid of the drawings, various modifications and alternatives are conceivable without departing from the teaching underlying the invention. Therefore, the invention is not intended to be limited to the various aspects described herein, but rather is defined by the scope of the appended claims.