MXPA99011883A - Transfer and centering system for contact lenses - Google Patents

Abstract

A method for transferring a lens-shaped article (23) from a first support (25) to a centered position on a second support (31) employs a transfer tool (1) having a slideable plunger (11) and plunger sleeve (21) that cooperates with the first and second support to ensure that the article is oriented in a desired manner when transferred.

Description

TRANSFER SYSTEM AND CENTERING FOR CONTACT LENSES BACKGROUND OF THE INVENTION The present invention relates to a method and apparatus for transferring an article configured in the form of a lens between different stages of a manufacturing process, while ensuring that the article remains centered during the transfer. The invention is especially useful for the transfer of contact lenses. Small, delicate workpieces, such as contact lenses, are difficult to transfer through multiple stages of a manufacturing process. This is especially true if it is desired to keep the contact lens in a desired orientation, such as in a centered position during the manufacturing process. Although automatic processes minimize human contact with lenses, thus reducing the possibility of human error, the challenge is to design processes that ensure that the lens is properly oriented when transferred between stages.

COMPENDIUM OF THE INVENTION The invention provides a method for transferring an article configured in the form of a lens from a first support to a centered position on a second support. The invention provides a reliable mechanism to ensure that the article remains centered during the transfer between the manufacturing steps, either in fully automatic manufacturing stages or in assisted manufacturing steps with an operator.

Additionally, the invention provides an apparatus for carrying out several preferred embodiments. The method of this invention involves removing the article configured in the form of a lens from the first support with a transfer tool, in such a way that the article is centered with respect to the transfer tool and transferring the article to a centered position on the second. reception surface of the support. The transfer tool comprises a plunger comprising an elongate body, a tip at a lower end of the elongated body including a contact surface, a duct extending through the elongated body, which is connected to a vacuum source and which it terminates in an opening in the contact surface of the tip, and a sleeve that surrounds the elongate body of a plunger, the sleeve and the plunger being slidable therebetween. The article is removed from the first support by moving the plunger to an extended position with respect to the sleeve, placing the tip close to the concave surface of the article and activating the vacuum source of the transfer tool. The article is transferred to a centered position on the second receiving surface of the support by moving the plunger to a retracted position with respect to the sleeve, placing the sleeve on a portion of the second support having an outer diameter that generally corresponds to an internal diameter of the sleeve. cuff, and contacting the convex surface of the article with the receiving surface and inactivating the vacuum source of the transfer tool.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic perspective view of a transfer tool according to several preferred embodiments. Fig. 2 is an exploded view of the transfer tool of Fig. 1; Fig. 3 is a cross-sectional view of the transfer tool with the plunger in an extended position; and Figure 4 is a partial cross-sectional view of this transfer tool with the plunger in a retracted position.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to the drawings, a transfer and centering tool 1 is seen in the various figures, which is used to transfer an article configured in the form of a lens 23 from a first support to a centered position on a second support. For the illustrative embodiment described, the contact lens 23 is initially supported on and retained in a mold 25, the mold being part of a set of molds in which the lens was melted. For this embodiment, the mold 25 and the lens 23 are retained in a fixing device designed to maintain the mold / lens combination and to release the contact lens from the mold. The second support is part of a flanging apparatus having a spindle shaft that supports the lens during the flanging operation. However, it is understood that the transfer tool of this invention can be used with other types of equipment used in various lens manufacturing processes, where it is desired to transfer the lens between sub-stations while ensuring that the lens is oriented in a desired, predetermined manner. As seen in Figures 1 and 2, the transfer tool 1 includes the plunger 11 and the piston sleeve 21. The plunger 11 and the plunger sleeve 21 are slidable with respect to each other, more specifically, the plunger 11 it can move between an extended position and a retracted position with respect to the plunger sleeve 21 by means of a plunger driver. (In Figure 1, the plunger 11 is in an extended position). For the illustrated embodiment, the plunger driver is a reversed pneumatic return cylinder 2 with a conventional spring, having a driving rod 6, the rod 6 extending and retracting to provide a stroke. The actuator 2 can be fixed through the connector 3 to the tube 5, and fixed to the piston sleeve -21 through a cylindrical adapter 7. The tube 5 leads to a source of pressurized air to activate the pneumatic cylinder 2. The plunger 11 it includes the tip 12 at its lower end to contact the concave surface of the contact lens, as described in more detail below. The apparatus further includes the tube 10 leading to a vacuum source which can be fixed to the cylinder adapter 7 through the adjusting device 9. Referring now to Figure 2, for the embodiment described, the upper end of the cylinder pneumatic 2 may include female threads for connection with male threads on the connector 3, and the lower end of the pneumatic cylinder 2 may include male threads for connection with female threads on the cylinder 7 adapter (the threaded connections are not shown in the drawings) . The connector 3 has an opening for receiving the tube 5, which, as mentioned, is connected to a source of pressurized air. The cylindrical adapter 7 includes the side opening 8 for connection to the adjusting device 9. The lower end of the rod 6 can be connected to the plunger 11 through connection elements such as a spring washer 13, a cylindrical hollow 15, and a retaining ring 17. For the illustrated embodiment, the cylindrical bushing 15 has a lateral groove 16 which, in combination with the conduit 18 extending through the elongated body of the plunger, provides a conduit for the vacuum source extends from the tube 10, through the adjusting device 9 and the plunger 11, to an opening of the conduit 18 at the tip 12. The bush 15 is fixed to the rod 6, for example with a threaded connection. The internal retaining ring 17 is locked in the threads of the plunger 11 to secure the bushing 15 and the washer 13, the washer 13 allowing the bushing 15 to float slightly with respect to the plunger 11. The plunger bushing 21 can include female threads for connection with the male threads on the connector 3; accordingly, when the apparatus is assembled as shown in Figure 1, the sleeve 21 surrounds the plunger 11. For the embodiment described, the sleeve 21 remains in a fixed position with respect to the connector 3 and the adapter 7, while that the plunger 22 is slidable between the extended and retracted positions by the activation of the rod 6.

The lower end of the plunger 11 has a tip 12, which is preferably in the form of a domed, convex surface with an opening formed on this surface from the duct 18. An O-ring 19 can be placed around the tip 12, so that the The concave surface of a contact lens 23 is brought into contact with the tip 12 and the O-ring 19 when it is in contact with the plunger 11 (as seen in Figure 3). This lower end of the plunger 11 may include a small ring 14 around it, to facilitate centering of the contact lens with respect to the tip 12. As mentioned, for the described embodiment, the contact lens is further supported. -nally on the mold 25 in which it has been molded. The mold 25 is retained in a fixing device for mechanically releasing the contact lens 23 adhered to the mold 25. This adapter includes a support 28 for the lower portion of the mold 25 and a shearing ring 27. When the shearing ring 27 applies Pressing the mold 25 around the periphery of the contact lens to alter the mold 25, the lens is mechanically released from the mold. As seen in Figure 3, an upper portion of the shearing ring 27 extends above the mold 25, and this ring-like member has an inner circumference which generally corresponds to an outer circumference of the plunger 11; since the mold 25 is centered with respect to the shearing ring 27 and the lens 23 is centered with respect to the mold 25, this ensures that the plunger 11 is centered with respect to the mold 25 (and the lens 23) when it is brought into contact with the lens. This fastening device may additionally include the ring-like member 26 which serves to facilitate an operator guiding the plunger in the shear ring. The fixation device may further include the conduit 29, which extends through the body 30, to introduce pressurized air to the mold 25 around the periphery of the lens 23, as described in more detail below. The second support, to which the lens is transferred may be an apparatus for mechanically beading the lens, which includes the shaft 31. The shaft 31 is mounted on a spindle shaft (not shown). In operation, as illustrated in Figure 3, the plunger 11 is inserted into the ring 27 of the dry release device with the plunger 11 extended beyond the plunger sleeve 21. The lens 23 is mechanically released from the lens mold 25 and a blow of air is supplied through the duct 29 to assist in lifting the lens from the mold 25. The vacuum source connected through the tube 10 is activated such that a vacuum is created in the opening of the tip 12 in contact with the lens, and the lens is then held on the tip of the plunger of the transfer tool maintaining the vacuum until the lens is transferred to the next station. As mentioned, the plunger 11 is centered with respect to the mold 25 and the lens 23 when its tip is in contact with the lens 23, and the centering of the lens with respect to the tip 12 is further facilitated by retaining the lens in the recess formed by the ring 14 which is slightly larger than the outer diameter of the lens. The piston of the transfer tool 11 is then retracted into the piston sleeve 21. With the piston retracted inside the piston sleeve, the sleeve 21 is slid on the shaft 31, until it abuts against the O-ring 33, such The combination has the configuration shown in FIG. 4. The outer diameter of the portion of the shaft 31 receiving the sleeve 21 corresponds generally to the internal diameter of the sleeve 21. Accordingly, the lens 23 is now centered with respect to the axis 31. For the described embodiment, the shaft 31 additionally includes the ring 32 and the O-ring 33 contained inside, serving the o-rings and the ring as a surface for receiving the lens and further facilitating the centering of the lens with respect to the axis 31. After the lens is seated on this surface receiving the shaft, an axis vacuum is activated (The vacuum source of the shaft is not shown, but is connected to the conduit 35) to hold the lens in position. When sufficient vacuum is established to maintain the lens on the shaft, a control system automatically deactivates the vacuum source of the transfer tool and activates the pneumatic cylinder 2 to extend the plunger. The transfer tool is now ready for the next cycle, and the lens is ready for processing in the flange forming device. Various embodiments of the present invention are apparent. As mentioned previously, the article configured in the form of a lens can be transferred between some stations where the exact positioning of a lens is desired. As another example, in the described embodiment, an operator can manually place the transfer tool between the first and second supports, but the transfer tool can be mounted on a machine so that the transfer is achieved by robotics instead from by an operator. Other variations and embodiments will be apparent to a person skilled in the art.

Claims (20)

Claims

1. An apparatus for transferring an article configured in the form of a lens from a first support to a centered position on a second support, wherein said article configured in the form of a lens includes a concave surface and a convex surface, the first support includes a support surface for supporting the convex surface of the article and the second support includes a receiving surface for receiving the convex surface of the article, said apparatus comprising: (a) a plunger comprising an elongate body, a tip at a lower end of the elongated body, including a contact surface, and a conduit extending through the elongate body, said duct being connected to a vacuum source and ending in an opening in the contact surface of the tip; Y (b) a sleeve surrounding the elongate body of the plunger, said plunger and said sleeve being slidable with respect to each other, wherein the second support includes a portion having an outer diameter that generally corresponds to an internal diameter of the plunger sleeve.

2. The apparatus of claim 1, wherein the first support includes a ring-like member, extending above the support surface, having an internal diameter that generally corresponds to an outer diameter of the plunger body.

3. The apparatus of claim 1, wherein the first support includes a concave supporting surface generally corresponding in configuration to the convex surface of the article configured in the form of a lens.

4. The apparatus of claim 3, wherein the first support includes a mold member, in which the shaped article is fused in the form of a lens, such that the article configured in the form of a lens is supported on a concave molding surface of the member of the mold and the ring-like member extends above the molding surface and is centered with respect to the molding surface.

5. The apparatus of claim 1, wherein the second support includes a spindle axis, such that the article configured in the form of a lens is received on a receiving surface at one end of the shaft, and an outer diameter of the shaft body corresponds to generally to the internal diameter of the piston sleeve.

6. The apparatus of claim 5, wherein the receiving surface at the end of the shaft includes an O-ring to contact the convex surface of the article.

7. The apparatus of claim 5, wherein the receiving surface of the shaft has an opening therein, which is connected to a vacuum source of the example.

8. The apparatus of claim 1, wherein the contact surface of the tip includes an O-ring for contact with the concave surface of the article.

9. The apparatus of claim 1, wherein the plunger is movable with respect to the sleeve between a retracted position and an extended position.

10. The apparatus of claim 1, wherein the article configured in the form of a lens is a contact lens.

11. A method of transferring an article configured in the form of a lens from a first support to a centered position on a second support, said article configured in the form of a lens concave surface and a convex surface, the first support including a support surface for supporting the convex surface of the article, and the second support including a receiving surface for receiving the convex surface of the article, said method comprising: (a) removing the article from the first support with a transfer tool, such that the article is centered with respect to the transfer tool, the transfer tool comprising a plunger comprising an elongated body, a tip at one end bottom of the elongate body including a contact surface, a conduit extending through the elongated body, said conduit being connected to a vacuum source and ending in an opening in the contact surface at the tip, and a sleeve surrounding the elongate body of the plunger, the sleeve and the plunger being slidable with respect to each other; wherein the article is removed from the first support by placing the tip proximal to the concave surface of the article, while the plunger is in an extended position with respect to the sleeve and activating the vacuum source of the transfer tool; (b) transferring the article to a centered position on the second receiving surface of the support, moving the plunger to a retracted position with respect to the sleeve, placing the sleeve on a portion of the second support having an outer diameter corresponding generally to a inner diameter of the sleeve, and contacting the convex surface of the article with the receiving surface and inactivating the vacuum source of the transfer tool.

12. The method of claim 11, wherein the first support includes a ring-like member extending above the first support surface having an internal diameter that generally corresponds to an outer diameter of the plunger body, and the method includes inserting the plunger body into the ring-like member, at the same time that the plunger extends with respect to the sleeve, to place the tip close to the concave surface of the article.

13. The method of claim 11, wherein the first support includes a concave support surface generally corresponding in configuration to the anterior surface of the article configured in the form of a lens, and the ring-like member is centered with respect to the Concave support surface.

14. The method of claim 13, wherein the first support includes a mold member, in which the article configured in the form of a lens is fused, such that the article configured in the form of a lens is supported on a concave molding surface of the member of the mold, and the ring-like member extends above the molding surface and is centered with respect to the molding surface.

15. The method of claim 11, wherein the second support includes a spindle axis, such that the article configured in the form of a lens is received on a receiving surface at one end of the shaft, the outer diameter of the shaft body corresponding to the inner diameter of the plunger sleeve, and wherein the method includes placing the sleeve on the shaft body to contact the surface of the previous article with one end of the shaft.

16. The method of claim 15, wherein the surface receiving the shaft includes an O-ring to contact the convex surface of the article.

17. The method of claim 15, wherein the surface receiving the shaft has an opening in the interior connected to a vacuum source of the shaft, and wherein the method includes activating the vacuum source of the shaft when the convex surface of the article is in contact with the receiving surface of the shaft.

18. The method of claim 11, wherein the article configured in the form of a lens is a contact lens.

19. A method of transferring a contact lens, wherein a convex surface of said contact lens is supported and centered with respect to a concave support surface of a first support, said method comprising: (a) transferring the contact lens from the first support to a support tool and centering the contact lens with respect to the support tool, the transfer tool comprising a plunger comprising an elongated body, a tip at a lower end of the elongate body having an opening connected to a vacuum source, and a sleeve surrounding the plunger body, wherein a concave surface of the contact lens comes into contact with the tip of the transfer tool at the same time as the plunger is in an extended position with respect to the sleeve and the vacuum source is activated; Y (b) transferring the contact lens from the transfer tool to a second support and centering the contact lens with respect to a receiving surface of a second support, where the convex surface of the contact lens is brought into contact with a receiving surface on the second support, while the plunger is in a retracted position with respect to the sleeve.

20. The method of claim 19, wherein step (b) further comprises activating a vacuum source connected to the second support receiving surface.