Abstract
A gripper for the transportation of an ophthalmic lens comprises: a gripper shaft having a longitudinal shaft axis and a fluid channel extending through the gripper shaft; a connector at the proximal end of the gripper shaft for connecting a flexible supply tube and the proximal end of the gripper shaft; a support movably accommodating the gripper shaft; a spring mounted between the support and the gripper shaft, the spring biasing the gripper shaft distally away from the support; and a gripper head attached to the gripper shaft at a distal end portion thereof, the gripper head having a further fluid channel extending therethrough, the gripper head further having a suction opening which is centrally arranged in a distal end surface of the gripper head, the suction opening being in fluid communication with the fluid channel of the gripper shaft through further fluid channel.
The gripper head is configured to be pivotable about a pivot portion of the gripper head.
Claims
1. Gripper (3) for the transportation of an ophthalmic lens (2), the gripper (3) comprising a gripper shaft (30) having a longitudinal shaft axis (300) and a fluid channel (301) extending through the gripper shaft (30) in the direction of the longitudinal shaft axis (300); a connector (31) arranged at the proximal end of the gripper shaft (30) for connecting a flexible supply tube (4) and the proximal end of the gripper shaft (30) such that the flexible supply tube (4) is in fluid communication with the fluid channel (301) of the gripper shaft (30) in a fluid-tight manner, for the supply of vacuum or overpressure to the fluid channel (301); a support (32) movably accommodating the gripper shaft (30) in a direction of the longitudinal shaft axis (300); a spring (33) mounted between the support (32) and the gripper shaft (30), the spring (33) biasing the gripper shaft (30) distally away from the support (32) in the direction of the longitudinal shaft axis (300); and a gripper head (34; 36) attached to the gripper shaft (30) at a distal end portion of the gripper shaft (30), the gripper head (34; 36) having a further fluid channel (341; 361) extending through the gripper head (34; 36) along a longitudinal head axis (340; 360) coincident with the longitudinal shaft axis (300), the gripper head (34; 36) further having a suction opening (342; 362) which is centrally arranged in a distal end surface (343; 363) of the gripper head (34; 36) at a distal end of the further fluid channel (341; 361), the suction opening (342; 362) being in fluid communication with the fluid channel (301) of the gripper shaft (30) by means of the further fluid channel (341; 361); wherein the gripper head (34; 36) is configured to be pivotable about a pivot portion (346; 366) of the gripper head (34; 36).
2. Gripper according to claim 1, wherein the gripper head (34; 36) further comprises a plurality of recessed channels (349; 369) formed in the distal end surface (343; 363) of the gripper head (34; 36), the recessed channels (349; 369) being connected to the centrally arranged suction opening (342; 362) and extending in a direction outwardly away from the centrally arranged suction opening (342; 362).
3. Gripper according to claim 1, wherein the gripper head (34; 36) has a gripping portion (344; 364) arranged at the distal end of the gripper head (34; 36) and a first conically shaped portion (345; 365) tapering from a largest diameter (d1; d4) of the gripping portion (344; 364) towards the pivot portion (346; 366) which is cylindrical and has the smallest diameter (d2; d5) of the gripper head (34; 36), the cylindrical pivot portion (346; 366) being arranged proximal to the first conically shaped portion (345; 365).
4. Gripper according to claim 3, wherein the gripper head (34; 36) further has a second conically shaped portion (347; 367) widening from a proximal end of the cylindrical pivot portion (346; 366) to a cylindrical mounting portion (348; 368) of the gripper head (34; 36) having a diameter (d3; d6) larger than the diameter (d2; d5) of the cylindrical pivot portion (346; 366), the cylindrical mounting portion (348; 368) being arranged at the proximal end of the second conically shaped portion (347; 367) of the gripper head (34; 36).
5. Gripper according to claim 4, wherein the largest diameter (d1) of the gripping portion (344) is in the range of 8 mm to 12 mm, wherein the first conically shaped portion (345) has an axial length (e1) in the range of 2 mm to 5 mm, wherein the pivot portion (346) has a diameter (d2) in the range of 3 mm to 6 mm and an axial length (e2) in the range of 1 mm to 4 mm, wherein the second conically shaped portion (347) has an axial length (e3) in the range of 1.5 mm to 3 mm, and wherein the diameter (d3) of the mounting portion (368) is in the range of 6 mm to 9 mm.
6. Gripper according to claim 4, wherein the largest diameter (d4) of the gripping portion (364) is in the range of 12 mm to 17 mm, wherein the first conically shaped portion (365) has an axial length (e6) in the range of 2 mm to 4 mm, wherein the pivot portion (366) has a diameter (d5) in the range of 5 mm to 7 mm and an axial length (e7) in the range of 1 mm to 4 mm, wherein the second conically shaped portion (367) has an axial length (e8) in the range of 1 mm to 3 mm, and wherein the diameter (d6) of the mounting portion (368) is in the range of 6 mm to 9 mm.
7. Gripper according to claim 1, wherein the gripper further comprises a plug (35) attached to the distal end of the gripper shaft (30), with the gripper head (34; 36) releasably mounted to the plug (35), and wherein the plug (35) comprises a plug channel (351) extending through the plug (35) along a longitudinal plug axis (350) coincident with the longitudinal shaft axis (300) and with the longitudinal head axis (340; 360), the plug channel (351) being in fluid communication both with the fluid channel (301) of the gripper shaft (30) and with the further fluid channel (341; 361) extending through the gripper head (34; 36).
8. Gripper according to claim 1, wherein the gripper head (34; 36) is made of an elastic material having a hardness Shore A in the range of 30 to 90 at room temperature, in particular silicone rubber, natural rubber or fluorinated rubber.
9. Gripper according to claim 1, wherein the connector (31) comprises a set sleeve (310) resting on the support (32) and threadingly accommodating a proximal end portion (302) of the gripper shaft (30) at a distal end of the set sleeve (310); a fitting sleeve (312) arranged in the set sleeve (310) proximal to the proximal end portion (302) of the gripper shaft (30), the fitting sleeve (312) having a sleeve channel (313) extending through the fitting sleeve (312) and being bounded by a sleeve channel wall (314), the flexible supply tube (4) extending through the sleeve channel (313) and being fittingly connected to the sleeve channel wall (314) in a fluid-tight manner, with a distal end portion of the flexible supply tube (4) extending beyond a distal end of the fitting sleeve (312); and a locking screw (315) threadingly received in a proximal end portion of the set sleeve (310′) proximal to the fitting sleeve (312), the locking screw (314) having a screw channel (316) extending therethrough, with the flexible supply tube (4) extending through the screw channel (316) and further through the sleeve channel (313) of the fitting sleeve (312), the locking screw (315) further having a distal abutment surface (317) abutting against a proximal abutment surface (318) of the fitting sleeve (312) pressing the fitting sleeve (312) towards a proximal end face (303) of the gripper shaft (30), thus clamping the distal end portion (40) of the flexible supply tube (4) that extends beyond the distal end of the fitting sleeve (312) between a distal abutment surface of the fitting sleeve (312) and the proximal end face (303) of the gripper shaft (30), thereby establishing a fluid-tight fluid communication between the flexible supply tube (4) and the fluid channel (301) of the gripper shaft (30).
Description
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0042] Further advantageous aspects of the gripper according to the invention will become apparent from the following description of embodiments with the aid of the schematic drawings, in which:
[0043] FIG. 1 shows a perspective view of portion of a treatment carrier comprising baskets for accommodating contact lenses and carrying them through one or more liquid treatment baths;
[0044] FIG. 2 shows a sectional view of an embodiment of the gripper according to the invention arranged above an individual basket of the treatment carrier containing a contact lens;
[0045] FIG. 3 shows an enlarged view of the detail III of FIG. 2;
[0046] FIG. 4 shows a side view of a plurality of grippers according to the invention at the time of picking up a corresponding plurality of contact lenses from the respective baskets of the treatment carrier;
[0047] FIG. 5 shows an enlarged view of the detail V of FIG. 4;
[0048] FIG. 6 shows an enlarged view of detail VI of FIG. 2;
[0049] FIGS. 7-10 show different views of a first embodiment of the gripper head of the gripper according to the instant invention; and
[0050] FIGS. 11-14 show different views of a second embodiment of the gripper head of the gripper according to the instant invention.
DETAILED DESCRIPTIONS
[0051] In FIG. 1 a portion of a treatment carrier 1 known in the art is shown. Such treatment carrier 1 is disclosed, for example, in WO 2018/185630. Treatment carrier 1 comprises a frame 10, e.g. made of aluminum, stainless steel or a suitable plastic material, as well as carrier inserts 11 clicked into rectangularly shaped compartments 12, one carrier insert 11 into each compartment 12. In the embodiment shown in FIG. 1, one carrier insert 11 comprises twenty baskets 110 arranged in five rows and four columns. For illustration purposes, some of the baskets 110 contain a contact lens 2. In practice, for efficiency reasons, typically each basket 110 contains a contact lens 2, and a plurality of treatment carriers 1 may be arranged one above the other to form a stack which is transported through the one or more liquid treatment baths.
[0052] FIG. 2 shows a sectional view of an embodiment of the gripper 3 according to the invention, arranged above an individual basket 110 of the carrier insert 11 of treatment carrier 1. Gripper 3 is shown in a position prior to picking up the contact lens 2 contained in basket 110. The purpose of FIG. 2 is to show the overall structure and arrangement of the gripper 3 relative to the basket 110 of the treatment carrier 1 in which the contact lens 2 to be picked up is contained, while details of this embodiment will be discussed with the aid of FIG. 3 and FIG. 6 showing the details III and VI of FIG. 2.
[0053] Gripper 3 comprises a gripper shaft 30 having a longitudinal shaft axis 300 (see FIG. 3), and further comprises a fluid channel 301 extending through gripper shaft 30 in the direction of the longitudinal shaft axis 300. A connector 31 is arranged at the proximal end of gripper shaft 30. Connector 31 connects a flexible supply tube 4 with the fluid channel 301 of gripper shaft 30 in a fluid-tight manner such that they are in fluid communication with one another, for the supply of vacuum or overpressure to the fluid channel 301 of gripper shaft 30. Connector 31 will be described in more detail below.
[0054] Gripper 3 further comprises a support 32 movably accommodating the gripper shaft in a direction of the longitudinal shaft axis 300. Support 32 of gripper 3 may be fixedly mounted to a gripper system to which a plurality of individual grippers 3 may be mounted. A tube holder 5 may be provided to support and hold flexible supply tube 4 and to guide it to the gripper 3. A spring 33 is mounted between the support 32 and the gripper shaft 30, the spring 33 biasing the gripper shaft 30 distally away from the support 32.
[0055] A gripper head 34 is attached to the gripper shaft 30 at the distal end of the gripper shaft 30, and in this embodiment the gripper head 34 is attached to the gripper shaft 30 with the aid of a plug 35 that is threadingly received by the gripper shaft 30. Plug 35 has a longitudinal plug axis 350 (see FIG. 3) and a plug channel 351 extending through the plug 35 along the longitudinal plug axis 350. The longitudinal plug axis 350 coincides with the longitudinal shaft axis 300.
[0056] Gripper head 34 is made of a flexible material such as, for example, silicone rubber, natural rubber, or fluorinated rubber, and can be mounted to the plug 35 by pushing the gripper head 34 axially over a retaining structure 352 provided on an outer surface of the plug 35. Due to the flexibility of the material the gripper head 34 is made of, the gripper head 34 is securely attached to the plug 35 and can also be easily replaced. Gripper head 34 has a longitudinal head axis 340 and a fluid channel 341 that extends through the gripper head 34 along the longitudinal head axis 340. Longitudinal head axis 340 is coincident both with the longitudinal shaft axis 300 as well as with the longitudinal plug axis 350. The fluid channel 301 extending through gripper shaft 30, the plug channel 351 extending through the plug 35, and the fluid channel 341 extending through gripper head 34 are thus in fluid communication with one another. Gripper head 34 further comprises a suction opening 342 which is arranged centrally in a distal end surface 343 of gripper head 34. Thus, vacuum or overpressure supplied to the flexible supply tube 4 is guided through fluid channel 301 of gripper shaft 30, further through plug channel 351 of plug 35, and finally through fluid channel 341 of gripper head 34 down to the suction opening 342.
[0057] Detail III of FIG. 2 is shown in FIG. 3 in an enlarged view, and illustrates a problem that may occur in picking up the contact lens 2 from the basket 110 of treatment carrier 1. As can be seen in FIG. 3, the longitudinal head axis 340 of the gripper head (and this holds, too, for the longitudinal plug axis 350 and for the longitudinal shaft axis 300, as these are coincident) may be slightly displaced laterally relative to a central longitudinal axis 111 extending through the basket 110. Thus, as the gripper 3 is moved downwardly for picking the contact lens 2 up the gripper head 34 may contact the back surface of contact lens 2 slightly eccentrically which—when using a conventional gripper—may possibly result in the contact lens 2 not being picked up properly. The gripper 3 according to the invention is capable of compensating for such slight lateral displacement, as is explained further below.
[0058] FIG. 4 shows a plurality of grippers 3 (by way of example five grippers 3) concurrently picking up a corresponding plurality of contact lenses 2 from the baskets 110. For example, the plurality of grippers 3 shown in FIG. 3 may concurrently pick up the contact lenses 2 contained in the baskets 110 of one column of the treatment carrier insert 11 of treatment carrier 1 shown in FIG. 1.
[0059] FIG. 5 shows the detail V of FIG. 5 for illustrating a further problem that may occur when conventional grippers are used (although grippers 3 according to the invention are shown in FIG. 5). This problem may come up as the treatment carrier inserts 11 comprising the baskets 110 may not be perfectly plane but may be shaped like a shallow dish. This is exaggeratedly shown in FIG. 5. While each of the gripper heads 34 is arranged at the same z-position, the outermost left gripper 3 and the outermost right gripper 3 contact the respective basket 110 (or a contact lens contained in the basket) while the second outermost left gripper 3 and the second outermost right gripper 3 as well as the central gripper 3 do not contact the respective basket 110 due to the shallow dish shape of the treatment carrier insert 11. Also, as can be seen in FIG. 5, the outermost left gripper 3 and the outermost right gripper 3 both contact the basket 110 eccentrically. With conventional rigid grippers this may lead to one or more contact lenses being improperly picked up or not being picked up at all. Or, in case the contact lenses adhere to the baskets 110 due to liquid adhering to the baskets 110, the contact lenses may become inverted while being picked up (i.e. the central portion of the contact lens may be sucked against the gripper surface while the radially outer portions of the contact lens may continue to adhere to the baskets 110, thus resulting in an inversion of the contact lens as the lens is picked up). The gripper 3 according to the invention is capable of avoiding such lens inversion, as is explained further below.
[0060] FIG. 6 shows the detail VI of FIG. 2 in an enlarged view. As can be seen there, connector 31 (see also FIG. 2) comprises a set sleeve 310. Set sleeve 310 threadingly accommodates a threaded proximal end portion 302 of gripper shaft 30 at a distal end of set sleeve 310. The distal end surface 311 of set sleeve 310 abuts against an upper surface 321 of support 32, so that the gripper shaft is secured against falling down. Spring 33 biases the gripper shaft 30 distally away from the support 32. Thus, with the aid of the set sleeve 310 it is possible to define the z-position of the distal end surface 343 of the gripper head 34 (see FIG. 3) relative to the support 32.
[0061] Connector 31 further comprises a fitting sleeve 312 which is arranged in the set sleeve 310 proximal to the proximal end portion 302 of gripper shaft 30. The fitting sleeve 312 has a sleeve channel 313 which is bounded by a sleeve channel wall 314 (inner wall of fitting sleeve 312). Flexible supply tube 4 extends through the sleeve channel 313 and is fittingly connected to sleeve channel wall 314 in a fluid-tight manner. For example, the outer diameter of the flexible tube 4 can be selected somewhat larger than the diameter of the sleeve channel 313. A distal end portion 40 of the flexible supply tube 4 extends beyond a distal end of the fitting sleeve 312.
[0062] Yet further, connector 31 comprises a locking screw 315 which is threadingly received in a proximal end portion of the set sleeve 310 proximal to fitting sleeve 312. Locking screw 315 has a screw channel 316 extending through the locking screw 315. The flexible supply tube 4 extends through the screw channel 316 and further through the sleeve channel 313 of fitting sleeve 312. Locking screw 315 has a distal abutment surface 317 and fitting sleeve 312 has a proximal abutment surface 318. Thus, by screwing locking screw 315 into set sleeve 310 until the distal abutment surface 317 of locking screw 315 abuts against the proximal abutment surface 318 of fitting sleeve 312, the fitting sleeve 312 is pressed towards a proximal end face 303 of gripper shaft 30. Thereby, the portion 40 of the flexible supply tube 4 that extends beyond the distal end of the fitting sleeve 312 is clamped between a distal abutment surface 319 of the fitting sleeve 312 and the proximal end face 303 of gripper shaft 30 and extends radially outwardly thus forming a fluid-tight seal. In this manner, a fluid-tight fluid communication is established between the flexible supply tube 4 and the fluid channel 301 of the gripper shaft 30.
[0063] In FIGS. 7-10 a first embodiment of the gripper head 34 is shown. FIG. 7 shows a perspective view, FIG. 8 shows a side view, FIG. 9 shows a bottom view, and FIG. 10 shows a sectional view along lines X-X of FIG. 9. This first embodiment of the gripper head 34 is specifically embodied for picking a contact lens 2 up from a basket 110 of the carrier insert 11 of the treatment carrier 1 shown in FIG. 1. That is, the contact lens 2 is picked up from the basket 110 in an air (i.e. gaseous) environment. As can be seen, the gripper head 34 comprises the fluid channel 341 that extends through the gripper head 34 along the longitudinal head axis 340 (see FIG. 10, in which the gripper head 34 is shown upside down). Gripper head 34 comprises a gripping portion 344 arranged at the distal end of the gripper head 34. This gripping portion 344 includes the distal end surface 343 and the centrally arranged suction opening 342. A plurality of recessed channels 349 are formed in the distal end surface 343 of gripper head 34. These recessed channels 349 are connected to the centrally arranged suction opening 342 and extend in a direction outwardly away from the centrally arranged suction opening, as can be seen best in FIG. 7 and FIG. 9. Gripping portion 344 has a largest diameter d1 (indicated by the arrows in FIG. 10). A first conically shaped portion 345 then tapers from the largest diameter d1 towards a cylindrical pivot portion 346 having a diameter d2 which is the smallest diameter of the gripper head 34 (again indicated by the arrows in FIG. 10). Gripper head 34 further comprises a second conically shaped portion 347 that widens from a proximal end of the cylindrical pivot portion 346 to a cylindrical mounting portion 348 which has a diameter d3 (again indicated by the arrows in FIG. 10) larger than the diameter d2 of the cylindrical pivot portion 346.
[0064] By way of example, the largest diameter d1 of the gripping portion 344 may be in the range of 8 mm to 12 mm. By way of example, gripping portion 344 may have an axial length e0 (see FIG. 8) in the range of 2 mm to 4 mm. The first conically shaped portion 345 may have an axial length e1 (see FIG. 8) in the range of 2 mm to 5 mm. Pivot portion 346 may have a diameter d2 (see FIG. 10) in the range of 3 mm to 6 mm, and may have an axial length e2 (see FIG. 8) in the range of 1 mm to 4 mm. The second conically shaped portion 347 may have an axial length e3 (see FIG. 8) in the range of 1.5 mm to 3 mm, and the mounting portion 348 may have a diameter d3 (see FIG. 10) in the range of 6 mm to 9 mm as well as an axial length e4 (see FIG. 8) sufficient for it to be securely retained by the retaining structure 352 provided on the plug 35 (see FIG. 3). The axial length e4 may be in the range of 2 mm to 5 mm.
[0065] Operation of the gripper 3 comprising gripper head 34 shown in FIGS. 7-10 is now described with the aid of FIG. 5 and FIG. 6. For that purpose, assuming that the carrier insert 11 of the treatment carrier 1 is slightly shaped like a shallow dish, as is shown in FIG. 5 and makes the lens pick-up process more demanding. The five grippers 3 shown in FIG. 5 are mounted to the mounting member 5 of the gripper system such that the lowermost position of the distal end surface 343 of all grippers 3 is at the same level. The mounting members 5 to which the grippers 3 are mounted are now concurrently moved downwards to make the gripper heads 34 contact the back surfaces of the contact lenses 2 (the contact lenses 2 not being shown in FIG. 5) and pick the contact lenses 2 up from the baskets 110 by applying vacuum through the suction openings 342 and the recessed channels 349 (see FIG. 7 and FIG. 9). Due to the shallow dish-like shape of the carrier insert 11 (FIG. 5), the distal end surfaces 343 of the gripper heads 34 of the outermost left and the outermost right gripper 3 will first touch the back surfaces of the respective contact lens 2 (and since the contact lenses 2 are not shown in FIG. 5 this will be explained with the aid of the baskets 110 in the following). Even though there is (partial) contact between the distal end surfaces 343 of the gripper heads 34 of the outermost left and outermost right gripper 3 and the corresponding basket 110, there is no such contact yet between the distal end surfaces 343 of the gripper heads 34 of the three inner grippers 3 and the corresponding baskets 110, as ca be seen in FIG. 5. The concurrent movement of all mounting members 5 with the grippers 3 attached thereto is then continued in the downward direction (z-direction) to a predetermined z-position which is chosen such that distal end surface 343 of all grippers 3, including the gripper heads of the three innermost grippers 3 are also in contact with corresponding baskets 110. Due to the partial contact of the distal end surfaces 343 of the gripper heads 34 of the outermost left and the outermost right gripper 3 and the corresponding basket 110, during continued downward movement of the mounting members 5 in the z-direction, the gripper heads 34 of the outermost left gripper 3 and of the outermost right gripper 3 pivot about the pivot portion 346 (see FIG. 8). That is, the gripper head 34 of the outermost left gripper 3 pivots outwardly to make its distal end surface 343 match the shape of the inner surface of the outermost left basket 110 of the carrier insert 11 of treatment carrier 1. Similarly, the gripper head 34 of the outermost right gripper 3 pivots outwardly to make its distal end surface 343 match the shape of the outermost right basket 110 of the carrier insert 11 of treatment carrier 1. Further, during the continued downward movement the gripper shaft 30 of those grippers 3 of which the distal end surfaces 343 of the gripper heads are already in contact with the corresponding basket 110, the gripper shafts 30 move upwardly against the resilient force of the respective spring 33 which makes the gripper head 34 stay in the contact with the respective basket 110 (and in practice with the back surface of the contact lens 2 to be picked up). As can be seen in FIG. 6, when a gripper shaft 30 moves upwardly and compresses the spring, the connector 31 is also moved upwardly. This upward movement is a guided movement as the gripper shaft 30 is guided in the support 32. At the time of reaching the predetermined z-position to which the mounting members 5 are moved down, the distal end surfaces 343 of the gripper heads 34 of all five grippers 3 are in perfect contact with the corresponding basket 110 (or in practice with the back surface of the contact lens 2). At that time, vacuum is supplied through the supply tubes 4. This vacuum is then guided through the fluid channel 301 of the gripper shaft 30 (see FIG. 4), through the plug channel 351 of the plug 35, and through the fluid channel 341 of the gripper head 34 down to the suction opening 342 and outwards in the recessed channels 349. Thus, the contact lens 2 which is in contact with the distal end surface 343 and the gripper head 34 of the respective gripper is adhered to the distal end surface 343 of the gripper head 34 of the respective gripper 3 while at the same time this distal end surface perfectly matches the shape of the back surface of the contact lens 2. The supports 32 are then moved upwardly (i.e. in the z-direction but opposite to the direction of the downward movement for picking the contact lenses 2 up) with the vacuum continuing to be supplied through the supply tubes 4. Thus, the contact lenses 2 remain adhered to the distal end surfaces 343 of the gripper heads 34 of the grippers 3 and the grippers 3 can then be moved to a destination location. Byway of example, the destination location may be transfer station of a lens inspection module where inspection cuvettes are waiting to receive the contact lenses 2 transferred from the baskets 110 of the carrier insert 11 of the lens carrier 1. The contact lenses 2 can then be released from the grippers 3 at the destination location by either terminating the application of vacuum through the supply tubes 4 or by applying overpressure through the supply tubes 4. For example, at the destination location, the grippers 3 with the contact lenses 2 adhering to the distal end surfaces 343 of the gripper heads 34 can be moved downwardly into the inspection cuvettes, whereupon the supply of vacuum through the supply tubes may be terminated, or overpressure may be supplied through the supply tubes 4. Thus, the contact lenses 2 can be released from the grippers 3 (e.g. into the afore-described inspection cuvettes). As mentioned, this embodiment is an example of the application of the gripper 3 according to the invention in which the contact lens 2 is picked up from a basket 110 in an air environment, and may be placed into a receptacle in a liquid environment (cuvette filled with water or saline) or into a receptacle in an air environment (e.g. a packaging shell).
[0066] As already mentioned, the first embodiment of the gripper head shown in FIGS. 7-10 and described in detail above is specifically embodied for picking a contact lens up in an air environment, such as this is the case when picking a contact lens up from the basket 110 if the carrier insert 11 of the lens carrier 1 (this pick-up action occurring in an air environment). A second embodiment of the gripper head 36 is described in the following with the aid of FIGS. 11-14 showing a gripper head 36 that is particularly suitable for picking a contact lens up in a liquid environment. The remaining components of the gripper 3 remain the same and, therefore, they need not be described again. If the gripper head 34 described above were used in a liquid environment (this gripper head having a largest diameter of the gripping portion that is smaller than the diameter of the contact lens to be picked up), and a contact lens were picked up by the gripper in the liquid environment and the gripper subsequently moved upwards in the liquid environment, the quick upward movement of the gripper may cause the contact lens to get inverted due to the outer portions of the contact lens extending outwardly beyond the distal end surface of the gripper head, and further due to the viscosity of the liquid.
[0067] In FIGS. 11-14 a second embodiment of the gripper head 36 is shown. FIG. 11 shows a perspective view, FIG. 12 shows a side view, FIG. 13 shows a bottom view, and FIG. 14 shows a sectional view along lines XIV-XIV of FIG. 13. This second embodiment of the gripper head 36 is specifically embodied for picking a contact lens up in a liquid environment, e.g. from a conventional inspection cuvette of an inspection module in which the contact lens is inspected (rather than from a basket 110 of the carrier insert 11 of a treatment carrier 1). That is, the contact lens is picked up immersed in a liquid such as water or saline (rather than in a gaseous environment). As can be seen, the gripper head 36 comprises the fluid channel 361 that extends through the gripper head 36 along the longitudinal head axis 360 (see FIG. 10, in which the gripper head 36 is shown upside down). Gripper head 36 comprises a gripping portion 344 arranged at the distal end of the gripper head 34. This gripping portion 364 includes the distal end surface 363 and the centrally arranged suction opening 362. A plurality of recessed channels 369 are formed in the distal end surface 363 of gripper head 36. These recessed channels 369 are connected to the centrally arranged suction opening 362 and extend in a direction outwardly away from the centrally arranged suction opening, as can be seen best in FIG. 11 and FIG. 13. Gripping portion 364 has a largest diameter d4 (indicated by the arrows in FIG. 14). A first conically shaped portion 365 then tapers from the largest diameter d4 towards a cylindrical pivot portion 366 having a diameter d5 which is the smallest diameter of the gripper head 36 (again indicated by the arrows in FIG. 14). Gripper head 36 further comprises a second conically shaped portion 367 that widens from a proximal end of the cylindrical pivot portion 366 to a cylindrical mounting portion 368 which has a diameter d6 (again indicated by the arrows in FIG. 14) larger than the diameter d5 of the cylindrical pivot portion 366.
[0068] By way of example, the largest diameter d4 of the gripping portion 364 may be in the range of 12 mm to 17 mm. By way of example, gripping portion 364 may have an axial length e5 (see FIG. 12) in the range of 2 mm to 5 mm. The first conically shaped portion 365 may have an axial length e6 (see FIG. 12) in the range of 2 mm to 4 mm. Pivot portion 366 may have a diameter d5 (see FIG. 14) in the range of 5 mm to 7 mm, and may have an axial length e7 (see FIG. 12) in the range of 1 mm to 4 mm. The second conically shaped portion 367 may have an axial length e8 (see FIG. 12) in the range of 1 mm to 3 mm, and the mounting portion 368 may have a diameter d6 (see FIG. 14) in the range of 6 mm to 9 mm as well as an axial length e9 (see FIG. 8) sufficient for it to be securely retained by the retaining structure 352 provided on the plug 35 (see FIG. 3). The axial length e9 may be in the range of 2 mm to 5 mm.
[0069] As mentioned, one essential difference between the first embodiment of the gripper head 34 and the second embodiment of the gripper head 36 is that the largest diameter d4 of the gripping portion 364 of the second embodiment of the gripper head 36 is chosen such that it is larger than the typical diameter of soft contact lenses. As a consequence, when a contact lens is sucked against the distal end surface 363 of gripper head 36 in a liquid environment, the back surface of such contact lens is supported by the distal end surface over the entire diameter of the soft contact lens. Thus, when a soft contact lens is picked up by the gripper head 36 and thereafter adheres to the distal end surface 363 of gripper head 36, even a quick movement of the gripper 3 upward and out of the liquid does not involve the risk of the soft contact lens getting inverted as it is entirely supported by the distal end surface 363 of the gripper head 36 (no portions of the soft contact lens extending outwardly beyond the distal end surface 363).
[0070] As regards operation of the gripper 3 according to the invention having the second embodiment of the gripper head 36 attached to the plug 35 instead of the first embodiment of the gripper head 34, it is referred to the description given above, since the mode of operation is similar to the first embodiment. A detailed description of the mode of operation is therefore not repeated here.
[0071] While embodiments of the invention have been described with the aid of the drawings, the invention is not limited to these embodiments, but rather many changes and modifications can be made without departing from the technical teaching underlying the invention. Therefore, the scope of protection is not limited to the embodiments but is defined by the appended claims.
