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US-12617632-B2 - Gripper system for an ophthalmic lens

US12617632B2US 12617632 B2US12617632 B2US 12617632B2US-12617632-B2

Abstract

A gripper system comprises: a gripper shaft; a vacuum source; a first valve arranged between the vacuum source and the suction tube; a liquid reservoir; a source of pressurized gas; a second valve arranged between the source of pressurized gas and the suction tube or the liquid reservoir; a control unit for controlling the first valve and the second valve such that: for picking the ophthalmic lens up, suction is supplied to the suction tube; during transporting the ophthalmic lens, the suction tube is filled with liquid from the liquid supply tube; for releasing the ophthalmic lens from the gripper head, liquid is pressed through the fluid channel and through the suction opening of the gripper head.

Inventors

  • Felix Brinckmann
  • Michel Mühlig
  • Johannes Neumann
  • Nils Schweizer
  • Roger Biel

Assignees

  • ALCON INC.

Dates

Publication Date
20260505
Application Date
20240306

Claims (10)

  1. 1 . Gripper system ( 1 ) for picking an ophthalmic lens (CL) up at a start location ( 20 ), transporting the ophthalmic lens (CL) to a destination location ( 30 ) arranged in a liquid environment, and releasing the ophthalmic lens (CL) at the destination location ( 30 ) in the liquid environment, the gripper system ( 1 ) comprising a gripper shaft ( 10 ) having a hollow inner space extending through the gripper shaft in a longitudinal direction thereof; a separate suction tube ( 14 ) and a separate liquid supply tube ( 15 ) extending through the hollow inner space of the gripper shaft ( 10 ) towards a distal end of the gripper shaft, with a distal end of the suction tube ( 14 ) and a distal end of the liquid supply tube ( 15 ) being arranged in the inner space of the gripper shaft at a distance from the distal end of the gripper shaft; a connecting channel arranged in the inner space of the gripper shaft ( 10 ) and fluidically connecting the distal end of the suction tube ( 14 ) and the distal end of the liquid supply tube ( 15 ); a gripper head ( 11 ) attached to the gripper shaft ( 10 ) at the distal end of the gripper shaft and being configured to be pivotable about a pivot portion ( 111 ) of the gripper head ( 11 ), the gripper head having a fluid channel ( 113 ) extending through the gripper head ( 11 ) in a longitudinal direction thereof from a proximal end of the fluid channel ( 113 ) which is fluidically connected to the connecting channel, to a distal end of the fluid channel ( 113 ) which opens out into a suction opening ( 14 ) centrally arranged in a distal end surface ( 112 ) of the gripper head ( 11 ); a support ( 12 ) movably accommodating the gripper shaft ( 10 ) relative to the support ( 12 ) in the longitudinal direction (A) of the gripper shaft ( 10 ); a spring ( 13 ) mounted between the support ( 12 ) and the gripper shaft ( 10 ), the spring ( 13 ) biasing the gripper shaft ( 10 ) distally away from the support ( 12 ) in the longitudinal direction of the gripper shaft ( 12 ); a vacuum source ( 4 ) to which the suction tube ( 14 ) is fluidically connected; a first valve ( 40 ) arranged to establish or interrupt the fluidical connection between the vacuum source ( 4 ) and the suction tube ( 14 ); a liquid reservoir ( 6 ) to which the liquid supply tube ( 15 ) is fluidically connected; a source of pressurized gas ( 5 , 9 ); a second valve ( 50 , 90 ) arranged to establish or interrupt a fluidical connection between the source of pressurized gas ( 5 , 9 ) and either the suction tube ( 14 ) or the liquid reservoir ( 6 ) to which the liquid supply tube ( 15 ) is fluidically connected, for the supply of overpressure to either the suction tube ( 14 ) or to the liquid reservoir ( 6 ); a control unit ( 8 ) for controlling the first valve ( 40 ) and the second valve ( 50 , 90 ) such that: for picking the ophthalmic lens (CL) up at the start location ( 20 ) and making the ophthalmic lens (CL) adhere to the gripper head ( 11 ), the first valve ( 40 ) is opened to supply suction to the suction tube ( 14 ) and further to the suction opening ( 114 ) in the distal end surface ( 112 ) of the gripper head ( 11 ); for transporting the ophthalmic lens (CL) adhered to the gripper head ( 11 ) to the destination location ( 30 ), the first valve ( 40 ) remains open thereby continuing to supply suction to the suction tube ( 14 ) and drawing liquid through the liquid supply tube ( 15 ) and through the connecting channel into the suction tube ( 14 ) to fill the suction tube ( 14 ) with the liquid; for releasing the ophthalmic lens (CL) from the gripper head ( 11 ) at the destination location ( 30 ), the first valve ( 40 ) is closed to interrupt the supply of suction to the suction tube ( 14 ), and the second valve ( 50 , 90 ) is opened to supply overpressure either to the liquid in the suction tube ( 14 ) or to the liquid reservoir ( 6 ) to which the liquid supply tube ( 15 ) is connected thereby pressing the liquid through the fluid channel ( 113 ) extending through the gripper head ( 11 ) and through the suction opening ( 114 ) centrally arranged in the distal end surface ( 112 ) of the gripper head ( 11 ).
  2. 2 . Gripper system according to claim 1 , wherein the gripper head ( 11 ) at a proximal end thereof comprises a radially protruding flange ( 110 ), wherein the gripper shaft ( 10 ) further comprises a threaded cap ( 102 ) having a stepped bore ( 1020 ) accommodating the radially protruding flange ( 110 ) of the gripper head, the radially protruding flange ( 110 ) of the gripper head ( 11 ) resting on an inner abutment surface ( 1021 ) of the stepped bore ( 1020 ) while the rest of the gripper head ( 11 ) protrudes distally from the threaded cap ( 102 ), and wherein the gripper shaft ( 10 ) further comprises a threaded clamping sleeve ( 103 ) having a distal clamping surface ( 1030 ), the threaded clamping sleeve ( 103 ) being screwed into the threaded cap ( 102 ) to clamp the radially protruding flange ( 110 ) of the gripper head ( 11 ) between the distal clamping surface ( 1030 ) of the threaded clamping sleeve ( 103 ) and the inner abutment surface ( 1021 ) of the stepped bore ( 1020 ) of the threaded cap ( 102 ), the threaded clamping sleeve ( 103 ) further comprising first and second fluid guiding bores ( 1031 , 1032 ), extending longitudinally through the clamping sleeve ( 103 ), with the first fluid guiding bore ( 1031 ) being fluidically connected to the distal end of the suction tube ( 14 ) and with the second fluid guiding bore ( 1032 ) being fluidically connected to the distal end of the liquid supply tube ( 14 ), the threaded clamping sleeve ( 130 ) further comprising a transverse fluid guiding channel ( 1033 ) formed in the distal clamping surface ( 1030 ) and fluidically connecting the first and second fluid guiding bores ( 1031 , 1032 ), the first fluid guiding bore ( 1031 ), the second fluid guiding bore ( 1032 ) and the transverse fluid guiding channel ( 1033 ) together forming the connecting channel fluidically connecting the distal end of the suction tube ( 14 ) and the distal end of the liquid supply tube ( 15 ).
  3. 3 . Gripper system according to claim 2 , further comprising a suction tube fixation sleeve ( 140 ) and a liquid supply tube fixation sleeve ( 150 ), wherein the distal end of the suction tube ( 14 ) is fixed in the suction tube fixation sleeve ( 140 ), with the suction tube fixation sleeve ( 140 ) having a distal end abutting against a proximal abutment surface of the clamping sleeve ( 103 ), and with the suction tube fixation sleeve ( 140 ) being aligned with the first fluid guiding bore ( 1031 ) of the clamping sleeve ( 103 ) to fluidically connect the distal end of suction tube ( 14 ) and the first fluid guiding bore ( 1031 ) of the clamping sleeve ( 103 ), and wherein the distal end of the liquid supply tube ( 15 ) is fixed in the liquid supply tube fixation sleeve ( 150 ), with the liquid supply tube fixation sleeve ( 150 ) having a distal end abutting against the proximal abutment surface of the clamping sleeve ( 103 ), and with the liquid supply tube fixation sleeve ( 150 ) being aligned with the second fluid guiding bore ( 1032 ) of the clamping sleeve ( 103 ) to fluidically connect the distal end of the liquid supply tube ( 15 ) and the second fluid guiding bore ( 1032 ) of the clamping sleeve ( 103 ).
  4. 4 . Gripper system according to claim 3 , further comprising a retainer plate ( 105 ) having a distal abutment surface abutting against a proximal end of the suction tube fixation sleeve ( 140 ) and a proximal end of the liquid supply tube fixation sleeve ( 150 ), and further comprising a threaded compression piece ( 104 ) screwed into the gripper shaft and into the clamping sleeve ( 103 ) to press the distal abutment surface of the retainer plate ( 104 ) against the proximal end of the suction tube fixation sleeve ( 140 ) and the proximal end of the liquid supply tube fixation sleeve ( 150 ) to hold the distal end of the suction tube fixation sleeve ( 140 ) and the distal end of the liquid supply tube fixation sleeve ( 150 ) in abutment with the proximal abutment surface of the clamping sleeve ( 103 ).
  5. 5 . Method for picking an ophthalmic lens (CL) up at a start location ( 20 ), transporting the ophthalmic lens (CL) to a destination location ( 30 ) arranged in a liquid environment, and releasing the ophthalmic lens (CL) at the destination location ( 30 ) in the liquid environment, the method comprising: providing a gripper system ( 1 ) according to any one of the preceding claims ; providing an ophthalmic lens (CL) at the start location ( 20 ); moving the gripper shaft ( 10 ) to the start location and supplying suction to the suction tube ( 14 ) without liquid being supplied to the liquid supply tube ( 15 ), thereby supplying suction through the fluid channel extending through the gripper head ( 11 ) to the suction opening ( 114 ) centrally arranged in the distal end surface ( 112 ) of the gripper head ( 11 ), thus picking the ophthalmic lens (CL) up and making it adhere to the gripper head ( 11 ); with the ophthalmic lens (CL) adhered to the gripper head ( 11 ), continuing to supply suction to the suction tube ( 14 ) thereby drawing liquid from the liquid reservoir ( 6 ) through the liquid supply tube ( 15 ) and through the connecting channel into the suction tube ( 14 ), thus filling the suction tube ( 14 ) with liquid; moving the gripper shaft ( 10 ) with the ophthalmic lens (CL) adhered to the gripper head ( 11 ) to the destination location ( 30 ) in the liquid environment; at the destination location ( 30 ) in the liquid environment, releasing the ophthalmic lens (CL) from the gripper head ( 11 ) into the liquid environment by interrupting the supply of suction to the suction tube ( 14 ) and supplying overpressure either to the liquid in the suction tube ( 14 ) or to the liquid in the liquid supply tube ( 15 ), thereby causing the liquid to flow through the fluid channel ( 113 ) extending through the gripper head ( 11 ) and through the suction opening ( 114 ) centrally arranged in the distal end surface ( 112 ) of the gripper head ( 11 ).
  6. 6 . Method according to claim 5 , wherein the liquid reservoir ( 6 ) is pressure compensated and a proximal end of the liquid supply tube ( 15 ) is arranged in the pressure compensated liquid reservoir, and wherein at the destination location ( 30 ) in the liquid environment overpressure is supplied to the liquid in the suction tube ( 14 ).
  7. 7 . Method according to claim 6 , wherein the reservoir ( 6 ) comprises a container ( 60 ) which is closed by a lid ( 61 ), and wherein pressure compensation of the liquid reservoir is performed through an ambient pressure filter ( 62 ) arranged in the lid ( 61 ).
  8. 8 . Method according to claim 6 , wherein the reservoir ( 6 ) comprises a container ( 60 ) which is closed pressure-tight by a lid ( 61 ), and wherein pressure compensation of the liquid reservoir is performed through a pressure supply tube having one end thereof arranged in the interior of the container ( 6 ) through which pressurized gas ( 9 ) is introduced into the interior of the container ( 60 ) at a first predetermined pressure.
  9. 9 . Method according to claim 8 , wherein at the destination location ( 30 ) in the liquid environment the overpressure is supplied to the liquid in the liquid supply tube ( 15 ) by supplying the pressurized gas ( 9 ) through the pressure supply tube to the interior of the container ( 60 ) at a second predetermined pressure higher than the first predetermined pressure.
  10. 10 . Method according to claim 5 , wherein the reservoir comprises a liquid level sensor ( 63 ), and wherein a distal end of a reservoir supply tube is arranged in the reservoir whereas a proximal end of the reservoir supply tube is connected to a liquid source ( 7 ), and wherein in case a level of liquid lower than a predetermined threshold level is detected in the reservoir by the liquid level sensor ( 63 ), the supply of liquid from the liquid source ( 7 ) through the reservoir supply tube into the reservoir is triggered.

Description

This application claims the benefits under 35 USC § 119 (e) of U.S. provisional application No. 63/450,787, filed on 8 Mar. 2023, incorporated by reference in its entirety. FIELD OF THE DISCLOSURE The invention relates to a gripper system for an ophthalmic lens such as a contact lens, and in particular a soft contact lens (e.g. a silicone hydrogel contact lens). BACKGROUND In the mass manufacture of ophthalmic lenses such as contact lenses, and in particular soft contact lenses (e.g. silicone hydrogel contact lenses), the contact lenses are transported through various stations in automated production lines. For example, in the manufacture of soft contact lenses made of silicone hydrogel materials, the lens-forming material is cured in a mold to form a contact lens, and subsequently the cured lens is removed from the mold, extracted and/or hydrated and/or coated, and is then inspected. Those contact lenses that have successfully passed inspection are then transferred to a packaging module for packaging. As already described, in such automated production lines the contact lenses need to be transferred between several stations and/or modules of the production line. One such transfer takes place at a transfer station of a treatment module (in which the contact lenses are treated, e.g. extracted and/or hydrated and/or coated) where the contact lenses are transferred to an insertion station of a subsequent inspection module (in which the contact lenses are inspected) where the contact lenses are inserted into inspection cuvettes of the inspection module. In the treatment module, the contact lenses are transported through various chemical treatment baths (including water baths) in the baskets of stacked treatment carriers, each basket accommodating a contact lens during transportation and treatment in the baths. Treatment carriers suitable for this purpose are known, for example, from WO 2018/185630. At the transfer station, a plurality of contact lenses are concurrently transferred from the baskets of an uppermost treatment carrier of a stack into a corresponding plurality of inspection cuvettes—one lens from one basket into one inspection cuvette, respectively. Inspection cuvettes suitable for this purpose are known, for example, from WO 03/016855. The transfer of the contact lenses from the baskets into the inspection cuvettes is typically performed with the aid of grippers. To perform the transfer, at the transfer station of the treatment module a plurality of grippers is arranged above the baskets of the treatment carriers and is lowered to a predetermined lowermost axial position (z-position, lens pick-up position) in which a convex distal end face of a respective gripper touches the concave back surface of a respective contact lens or is arranged a very small distance above the respective contact lens. The gripper has one or more suction openings in its convex distal end face through which vacuum/suction is then applied to pick the contact lens up and make it adhere to the distal end face of the gripper. Once a said contact lens has been picked up by a said gripper and adheres to the distal end face thereof, the gripper with the contact lens adhered thereto is moved to the corresponding inspection cuvette and is then lowered into the inspection cuvette to another predetermined lowermost axial position (z-position, lens release position) in which the distal end face of the gripper with the contact lens adhered thereto is immersed in a liquid (e.g. water) contained in the inspection cuvette. Application of suction is then terminated and pressurized air is applied instead (‘overpressure pulse’) while concurrently the gripper is moved upwards, thus releasing (‘blowing off’) the contact lens from the distal end surface of the gripper and allowing the released contact lens in the liquid to settle down on the bottom of the inspection cuvette. For the subsequent inspection of the contact lens, the cuvette is pivoted to an inspection position in which automatic inspection of the lens is performed by a camera through a viewing glass of the inspection cuvette (see WO 03/016855). While this method is known to work well, there are a few problems that may arise in the afore-described process of picking the contact lens up from the basket of the treatment carriers with the aid of the afore-described gripper, transporting the contact lens adhered to the gripper and subsequently releasing it from the distal end face of the gripper into the liquid contained in the inspection cuvette. First of all, the grippers are typically stiff rigid grippers. This may be disadvantageous as not all of the treatment carriers are perfectly even and do not perfectly extend in a horizontal plane (x-y-plane) perpendicular to the axis of movement of the grippers (z-axis). For example, the treatment carriers may be very slightly curved (like a shallow dish) rather than being perfectly plane. As a consequence, the predetermined lowermost axial pos