WO2022251274A1

WO2022251274A1 - Block-alloy separator and method

Info

Publication number: WO2022251274A1
Application number: PCT/US2022/030802
Authority: WO
Inventors: Wolfgang Strobel
Original assignee: Coburn Technologies International, Inc.
Priority date: 2021-05-28
Filing date: 2022-05-25
Publication date: 2022-12-01

Abstract

A workpiece separator system including a gripper, a heat source in thermal communication with the gripper, the heat source configured to heat a block of the workpiece causing separation of an alloy puck from the block. A method for separating alloy from a block of a workpiece including heating the block, heating the alloy through the block, melting a thin interface between the block and the alloy, and removing from the block substantially all of the alloy as an alloy puck.

Description

BLOCK-ALLOY SEPARATOR AND METHOD

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Application No. 63/194,617, filed on May 28, 2021 and U.S. Application No. 17/716,620, filed on April 8, 2022, both of which are incorporated herein by reference in their entirety.

BACKGROUND

[0002] In the corrective lens manufacturing industry, automation that is capable of handling a class of things that may have differing geometry or orientation is important to maximizing efficiency and reducing costs. It is also desirable to avoid processes that result in toxic waste. An area of the industry where such toxic waste is created is the separation of blocking alloy from surface blocks. Often the alloy is melted from the surface blocks by immersing the blocks in hot water or using a hot water spray. While this is effective in removing the alloy from the block, it is not particularly efficient and results in water that must be treated as a hazardous waste product. The art would therefore well receive alternative processes that avoid such drawbacks.

SUMMARY

[0003] An embodiment of a workpiece separator system including a gripper, a heat source in thermal communication with the gripper, the heat source configured to heat a block of the workpiece causing separation of an alloy puck from the block.

[0004] An embodiment of a method for separating alloy from a block of a workpiece including heating the block, heating the alloy through the block, melting a thin interface between the block and the alloy, and removing from the block substantially all of the alloy as an alloy puck.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The following descriptions should not be considered limiting in any way.

With reference to the accompanying drawings, like elements are numbered alike:

[0006] Figure l is a perspective view of an embodiment of the block and alloy separation system disclosed herein;

[0007] Figure 1 A is a view to illustrate an inserter of the system;

[0008] Figure 2 is a view of a block with alloy adhered thereto (prior art); [0009] Figure 3 is a perspective view of a gripper as disclosed herein;

[0010] Figure 4 is another enlarged view of a portion of the system described herein illustrating cam plates;

[0011] Figure 5 is another enlarged view of the system illustrating collection bins and their placement relative to other components of the system;

[0012] Figure 6 is another enlarged view of a portion of the system with other components removed;

[0013] Figure 7 is another enlarged view illustrating a gripper and a block cartridge; and

[0014] Figure 8 is another enlarged view illustrating a block release actuator to discharge blocks.

DETAILED DESCRIPTION

[0015] A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

[0016] Referring to Figures 1 and 2, a block/alloy separation system 10 is illustrated. System 10 is a system for separating a low melting temperature alloy blocking material 12 from a surface block 14. The block 14 may be, in an embodiment, a Loh style surface block. The system 10 may be fully automated, partially automated, or manual in various embodiments. In any of these cases, automated or manual the overarching teaching relates to applied temperature at the block 14 used to melt a thin region of the alloy 12 immediately adjacent the block 14 to which the alloy 12 is adhered. Melting the thin region of alloy at this location, releases the majority of the alloy 12 as a solid alloy puck 13 from the block 14. Blocks 14 with alloy 12 still attached shall be referred to as “workpieces” 18 herein. Generally, the system 10 will pick up the workpiece 18, separate the alloy 12 from the block 14, and place the resulting alloy puck 13 into a collection container 20. The block 14 will be placed into a different collection container 22 or collected in a manner to facilitate loading into a blocking machine (not shown). A particular advantage of the system 10 is that more fully melted alloy is not mixed with water as it is in the prior art thus causing an operator to have to manage contaminated water as a byproduct of the process. The system 10 creates no contaminated water.

[0017] The system 10 may be a standalone system or may be employed in tandem with other lens manufacturing systems for even greater efficiency. In either case, and referring to Figure 1 illustrating an embodiment of system 10, a workpiece 18 is placed in and/or delivered to the system 10. This may, in an embodiment, be by way of a system conveyor 29 (continuously or discontinuously run).

[0018] As a workpiece 18 enters the system 10, it is moved along conveyor 16 until coming into contact with a gate 24 operated by a solenoid or similar whose function it is to allow one workpiece 18 at a time to proceed to a load area 34. Workpieces 18 that are not diverted pass through the system 10 without being separated into their component parts (alloy 12 and block 14).

[0019] At an end of the queue conveyor 16 and after gate 24 is disposed a load mechanism 32 that may be another conveyor or may be an actuator (pneumatic, electric, hydraulic, and combinations including at least one of the foregoing). Load mechanism 32 moves the individual workpieces 18 allowed through by the gate 24 into the load area 34. Alignment of workpieces 18 in the load area 34 are ensured by cam surfaces 36 and 38 that funnel individual workpieces 18 into the desired aligned position. Once the workpiece 18 is aligned in the load area 34, a workpiece inserter 40 (see Figure 1 A) comprising a vertically oriented actuator (pneumatic, electric, hydraulic, and combinations including at least one of the foregoing) raises the workpiece 18 and inserts it into a gripper 44 that is mounted to a displacement mechanism 42, that may be a turret as illustrated. It is to be understood however that the displacement mechanism 42 is not limited to a turret but could also comprise a linear movement device as well. A turret is illustrated for efficiency in floor space considerations. The turret may be operated for rotational movement by a stepper motor or servo motor, for example. The gripper 44 (see Fig 3) is a split circular-type gripper that is known to the art but differs in that in some embodiments, jaws 45 comprise thermally conductive material such as copper or aluminum to contact the workpiece 18. The gripper 44 may include an actuator to hold workpiece 18 but also may be simplified to require only a spring such that the workpiece 18 is forced into the gripper 44 by the inserter 40 causing the spring to stretch and admit the workpiece 18 to the jaws 45 of the gripper 44. The workpiece 18 then is held in the gripper 44 by the spring tension created by the position of the workpiece 18 in the gripper 44. Grippers 44 are positioned at each arm 46 of the turret 42. Arms 46 are spaced about the turret 42 for convenient access and positioning over various event locations and in embodiments allow for parallel operations at different stations of the turret 42.

[0020] Once a workpiece is loaded into a gripper 44, a heat source 48 is activated.

The heat source may be “on-turret” or may be “off-turret” in various embodiments. The gripper conveys the thermal energy to the block 12 that will melt alloy at the interface 50 and ultimately cause separation of the alloy puck 13 from the block 14 (see Fig. 2). Heating sources contemplated include inductive, resistive, radiant, conductive, convective, etc. including through the use of fluids. The heat source may be in the gripper 44, on another part of the turret 42 near the gripper 44, or off turret in a location that supports thermal transfer to the gripper 44. In Figure 3, the heating source 48 is embedded in the jaws 45 of the gripper 44. In Figure 7, a heating source 49 is illustrated on the turret near the gripper 44. In Figure 1, a schematic illustration of a heat source off the turret 42 is indicated at 51.

[0021] Induction is more efficient as a means of adding thermal energy if the gripper 44 is made of ferrous material. However, ferrous materials are not particularly effective thermal conductors. Greater energy or more time may be employed to solve the issue if inductive heating and ferrous gripper are desired. Alternatively, the interposition of a higher conductivity material such as copper or aluminum that is a part of the jaws 45 but in contact with the block 12 allows for the efficiency of inductive heating and the benefit of more conductive metals. If a resistive heater is employed, the thermal transfer to the gripper 44 may be accomplished by direct conduction, convection or radiation and the gripper 44 may be constructed entirely from a more conductive material such as copper.

[0022] Heating occurs while the turret 42 is stationary or moving but regardless of which, the heating is accomplished so that separated alloy puck 13, which departs block 14 essentially still in solid form but for the thin melt at the interface 50, may be deposited in an alloy collection bin 20 as soon as the turret 42 positions the workpiece 18 over that bin 20. Because the exact melt temperature at interface 50 is variable due to contaminants, etc., an embodiment hereof further includes a catch platform 54 (see Figs 4 and 5, which shows both an up and a down position of platform 54) that is actuated into place beneath the workpiece 18 by a catch actuator 56 (pneumatic, electric, hydraulic, etc.) when first loaded into the gripper 44, the platform transferring onto a cam 58 for rotation of the turret 42 and then falling with gravity after departing the cam 58 at the point that the alloy puck 13 is disposed above the bin 20 or other deposition location. Other locations include a tape-contaminated bin 22 to receive alloy that retains lens release tape thereon or a cartridge block repository 62 to receive blocks 14 for reuse. The catch platform 54 in some embodiments will be of a material or be coated with a material that is “anti-stick” with regard to alloy material. The catch actuator 56 may be reactivated to hold the catch platform up while above bin 20 if it is rather desired to deposit the puck 13 in bin 22 instead. [0023] Referring to Figures 6 and 7, cartridge block repository 62 is better illustrated. It can be seen that a number of block cartridges 64 are disposed to receive blocks 14 after separation from alloy puck 13. In order to ensure the blocks 14 do not jam, it is desirable to employ guide rods 66 that are brought into close proximity of the block 14 while in the gripper 44. Each block 14 is then released from gripper 44 to slide down rod 66 into cartridge 64. When cartridges 64 are full, they may be manually replaced by additional cartridges 64. It is to be appreciated that blocks 14 may also be depositable onto the guide rod 66 without the cartridge in place. This still functions to organize blocks for loading into other devices or simply into cartridges in another step if desired.

[0024] It is also contemplated to employ a sensor to determine if a block or alloy has been dropped at the location at which it should be dropped. For example, if an alloy puck 13is free of tape and intended to be dropped at bin 20, a sensor may confirm that indeed the alloy did drop out of the gripper 44 at that location. Sensors may also be positioned to detect drop off at bin 22 and block collector 62.

[0025] Referring to Figure 8, an additional station of turret 42 is for workpieces 18 that did not properly separate into block 14 and alloy puck 13. These workpieces are ejected from the gripper 44 by an actuator 47 usually located off-turret and configured to force the workpiece 18 out of the gripper 44. The actuator 47 may be for example an air cylinder. The unseparated workpieces 18 will be collected in another bin or be otherwise directed to a collection area for further processing.

[0026] In another aspect of this disclosure, the system 10 is configured to detect the presence of lens surface protection tape on the alloy puck 13, and place tape-contaminated alloy puck 13in bin 22, separate from alloy puck 13that does not have tape.

[0027] To ensure that contaminated alloy is not intermixed with clean separated alloy puck 13, the system uses one or more of a conductivity configuration or an optical interrogator. The conductivity configuration disposes two leads 70 and 72 on the inserter 40 that will contact the workpiece 18 when installing the same into a gripper 44. Since the tape is a good insulator and the alloy a good conductor, whether the leads are on tape or on alloy would be quite evident based upon the conductivity measured. Where conductivity is lower the alloy includes tape and needs to go in bin 22 while if conductivity is relatively higher, the alloy is free of tape and must be deposited in the bin 20. Alternatively, or in addition, the system 10 may also employ an optical sensor that monitors outer dimensions of the alloy 12 such that where tape protrudes from the alloy 12, the sensor will register the anomaly and recognize that particular alloy 12 as contaminated with tape. Alternatively, the sensor may be configured to recognize reflectance or a color differential between the alloy and the tape such that again, the sensor may determine if there is tape present and hence send the ultimately separated alloy puck 13 to the correct bin 22 for further processing to remove the tape.

[0028] Set forth below are some embodiments of the foregoing disclosure:

[0029] Embodiment 1 : A workpiece separator system including a gripper, a heat source in thermal communication with the gripper, the heat source configured to heat a block of the workpiece causing separation of an alloy puck from the block.

[0030] Embodiment 2: The system as in any prior embodiment wherein the gripper includes a jaw.

[0031] Embodiment 3: The system as in any prior embodiment wherein the jaw includes the heat source therein.

[0032] Embodiment 4: The system as in any prior embodiment wherein the heat source is inductive.

[0033] Embodiment 5: The system as in any prior embodiment wherein the heat source is resistive.

[0034] Embodiment 6: The system as in any prior embodiment further including a displacement mechanism configured to displace the gripped workpiece.

[0035] Embodiment 7: The system as in any prior embodiment wherein the displacement mechanism is a turret.

[0036] Embodiment 8: The system as in any prior embodiment further including a catch platform.

[0037] Embodiment 9: The system as in any prior embodiment further including a discharger configured to eject the block from the gripper.

[0038] Embodiment 10: The system as in any prior embodiment further including a lens surface protection tape detector.

[0039] Embodiment 11 : The system as in any prior embodiment wherein the detector is a conductivity detector.

[0040] Embodiment 12: The system as in any prior embodiment wherein the detector is an optical detector.

[0041] Embodiment 13: A method for separating alloy from a block of a workpiece including heating the block, heating the alloy through the block, melting a thin interface between the block and the alloy, and removing from the block substantially all of the alloy as an alloy puck. [0042] Embodiment 14: The method as in any prior embodiment further comprising transporting the workpiece to a gripper in a displacement mechanism, the heating being while moving the workpiece in the displacement mechanism.

[0043] Embodiment 15: The method as in any prior embodiment further comprising transporting the workpiece to a gripper in a displacement mechanism, the heating being while the workpiece is stationary in the displacement mechanism.

[0044] Embodiment 16: The method as in any prior embodiment further comprising disposing the block into a cartridge, onto a guide rod or both on a guide rod and in a cartridge.

[0045] Embodiment 17: The method as in any prior embodiment further comprising detecting lens protection tape on the alloy puck and if detected, depositing the alloy puck with tape in a separate bin from a bin into which alloy pucks without tape are deposited.

[0046] Embodiment 18: The method as in any prior embodiment wherein the heating is by induction.

[0047] Embodiment 19: The method as in any prior embodiment wherein the heating is by resistance.

[0048] Embodiment 20: The method as in any prior embodiment wherein the heating is imparted to the block by one or more of conduction, convection and radiance.

[0049] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, it should be noted that the terms “first,” “second,” and the like herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “about”, “substantially” and “generally” are intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” and/or “substantially” and/or “generally” can include a range of ± 8% or 5%, or 2% of a given value.

[0050] While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited.

Claims

What is claimed is:

1. A workpiece separator system comprising: a gripper; a heat source in thermal communication with the gripper, the heat source configured to heat a block of the workpiece causing separation of an alloy puck from the block.

2. The system as claimed in claim 1 wherein the gripper includes a jaw.

3. The system as claimed in claim 2 wherein the jaw includes the heat source therein.

4. The system as claimed in claim 1 wherein the heat source is inductive.

5. The system as claimed in claim 1 wherein the heat source is resistive.

6. The system as claimed in claim 1 further including a displacement mechanism configured to displace the gripped workpiece.

7. The system as claimed in claim 6 wherein the displacement mechanism is a turret.

8. The system as claimed in claim 1 further including a catch platform.

9. The system as claimed in claim 1 further including a discharger configured to eject the block from the gripper.

10. The system as claimed in claim 1 further including a lens surface protection tape detector.

11. The system as claimed in claim 10 wherein the detector is a conductivity detector.

12. The system as claimed in claim 10 wherein the detector is an optical detector.

13. A method for separating alloy from a block of a workpiece comprising: heating the block; heating the alloy through the block; melting a thin interface between the block and the alloy; and removing from the block substantially all of the alloy as an alloy puck.

14. The method as claimed in claim 13 further comprising transporting the workpiece to a gripper in a displacement mechanism, the heating being while moving the workpiece in the displacement mechanism.

15. The method as claimed in claim 13 further comprising transporting the workpiece to a gripper in a displacement mechanism, the heating being while the workpiece is stationary in the displacement mechanism.

16. The method as claimed in claim 13 further comprising disposing the block into a cartridge, onto a guide rod or both on a guide rod and in a cartridge.

17. The method as claimed in claim 13 further comprising detecting lens protection tape on the alloy puck and if detected, depositing the alloy puck with tape in a separate bin from a bin into which alloy pucks without tape are deposited.

18. The method as claimed in claim 13 wherein the heating is by induction.

19. The method as claimed in claim 13 wherein the heating is by resistance.

20. The method as claimed in claim 13 wherein the heating is imparted to the block by one or more of conduction, convection and radiance.