Debris removal apparatus for use in laser ablation

Abstract

An apparatus which selectively directs cutting debris in selected directions while a laser beam separates a workpiece in a multi-directional relation. In a first embodiment, the apparatus comprises a positionable member rotatable about the laser beam, a nozzle attachable to the positionable member, and a programmable logic controller integrated with the positionable member to selectively position the direction of the nozzle. In a second embodiment, the apparatus comprises a plurality of stationary nozzles positioned about the laser beam, a gas source connected to each nozzle, and a programmable logic controller integrated with the gas source to selectively provide a stream of gas to each nozzle and direct the cutting debris in selected directions.

Description

BACKGROUND OF THE INVENTION

[0002] The present invention relates to a laser cutting tool. In particular, the present invention relates to an apparatus for selectively directing cutting debris away from a preferred portion of a workpiece so that the cutting debris does not settle thereon.

[0003] Laser beams are used in numerous applications, including drilling, machining, scribing and cutting a variety of different materials. While using a laser beam in these types of applications, it is typical that cutting debris or smoke from the lasered material becomes airborne. These particles either immediately settle or suspend in the air for a period of time until they either settle upon the workpiece or elsewhere. In most circumstances, it is desirable that the particles do not settle upon the workpiece. An example of this would include the use of optically clear plastics.

[0004] When laser beams are used for cutting optically clear plastics, the laser beam typically cuts the workpiece into a preferred portion and a scrap portion. In this situation, it is important that the cutting debris be kept away from the preferred portion in order to keep the entire surface of the plastic workpiece optically clear. It is less important, if at all, as to what settles upon the scrap portion, which is either discarded or recycled for other uses.

[0005] In the event that cutting debris deposits upon the preferred portion, that portion must then be washed to remove the cutting debris, thus ensuring that the plastic is optically clear. This is burdensome and causes an additional cost to manufacturing. One way to ensure that cutting debris is not deposited upon the preferred portion of the optically clear workpiece is to place a cover sheet upon the entire workpiece. The laser beam cuts both the cover sheet and the workpiece at the same time, with the cutting debris settling upon the cover sheet. Upon completing the cutting process, the cover sheet is removed from the preferred portion of the workpiece, and then discarded. This is also burdensome and wasteful, with the cover sheet being an added expense that must be discarded after its use.

[0006] Thus, it is preferable to direct the cutting debris created by the laser beam from settling upon the preferred portion of the optically clear workpiece. There exists in the art stationary suction or blowing devices which achieve this purpose. However, these devices are somewhat limited to the application of either straight-line or purely radial cuts. These devices are not very effective when a multi-directional cut on a single workpiece is desired. As used herein, multi-directional cuts means a pattern of the preferred portion having an edge or line changing direction such as at a corner, a curve with either an increasing or decreasing radius, a curve having an inflection point, or any combination thereof. The positioning of the stationary blower and/or suction device tends to direct some or all of the cutting debris in a single direction. When a laser beam makes a multi-directional cut in relation to the workpiece, the direction that the cutting particles must be directed in order to resist deposition upon the preferred portion of the workpiece must change with the direction of the cutting path.

BRIEF SUMMARY OF THE INVENTION

[0007] The present invention is an apparatus that selectively positions a nozzle to pneumatically direct cutting debris away from a preferred portion of a workpiece wherein a laser beam separates the workpiece in a multi-directional relation. The apparatus comprises a member positionable about a laser beam cutting device, the nozzle attachable to the positionable member, and a programmable logic controller to selectively position the positionable member and nozzle.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a side view of a preferred embodiment of the present invention.

[0009] FIG. 2 is a top-plane view of the preferred embodiment of the present invention taken along line 2-2 of FIG. 1.

[0010] FIG. 3 is an exploded side view of the preferred embodiment of the present invention.

[0011] FIG. 4 is a side view of an alternative embodiment of the present invention.

[0012] FIG. 5 is a top plan view of the alternative embodiment of the present invention taken along line 5-5 of FIG. 4.

DETAILED DESCRIPTION

[0013] An apparatus to selectively direct cutting debris in various directions while a laser beam separates a workpiece, according to the preferred embodiment of the present invention, is generally indicated at 10 in FIG. 1. The apparatus 10 generally comprises a positionable laser device 12, capable of emitting a laser beam 14 for ablation purposes, a positionable member 16 maneuverable about the laser beam, and a nozzle 18 attachable to the positionable member 16. The nozzle 18 is selectively positionable and capable of pneumatically directing cutting debris 20 in a selected direction. For purposes of this application, the term cutting debris includes, but is not limited to, any type of particle, smoke, plasma or other byproduct emitted from the workpiece during the ablation or cutting of the workpiece by the laser beam.

[0014] The laser device 12 includes any type of laser well known in the art including gas lasers, excimer lasers, or Nd:YAG lasers. The laser device 12 is positionable in relation to a workpiece 22 by being attachable to a positionable bracket 24 (as illustrated in FIG. 3). The bracket 24 is attachable to a suitable structure (not shown). Preferably the workpiece 22 rests upon a X-Y directional worktable 26. The laser device 12 is positioned in proximate fashion to the worktable 26. Thus, in the preferred embodiment of the present invention, the X-Y directional worktable 26 moves in relation to the laser device 12, with the laser device 12 remaining in a stationary position with respect to the worktable 26. However, it is within the scope of the present invention to have the worktable 26 remain stationary while the laser device 12 moves in relation to the worktable 26.

[0015] The positionable member 16 of the present invention is preferably operably attachable to a stationary support member 28. The positionable member 16 preferably is rotatable about the stationary support member 28, preferably by a ball-bearing device, or similar operably rotatable means. The stationary support member 28 is attachable to the bracket 24 proximate the laser device 12, with the laser device 12 being positioned such that the emitted laser beam 14 passes through an aperture 30 contained within the stationary support member 28, as best illustrated in FIGS. 1 and 2. Preferably, the positionable member 16 includes a geared portion 32 attached thereto. The geared portion 32 provides a means to rotate the positionable member 16 by mechanically cooperating with a gear 34. The geared portion 32 mechanically cooperates with the gear 34 by being mateably engageable thereto. The gear 34 is mechanically driven by a drive 38, and preferably an electrical motor. A shaft 36 operably connects the drive 38 to the gear 34. However, alternative means to rotate the positionable member are within the scope of the present invention, including the use of a continuous V-belt in conjunction with cooperating channeled grooves connected to the positionable member and drive means.

[0016] The nozzle 18 is attached to the positionable member 16. The nozzle 18, which preferably includes a tube attachment 40, is attached to the positionable member 16 such that a direction of the tube 40, with the respect to the positionable member 16, remains constant. The length and configuration of the tube 40 is dependent upon the positioning of the positionable member 16 in relation to the workpiece 22 and worktable 26. Preferably, the tube 40 is positioned proximate an ablation point or area wherein the laser beam ablates or cuts the workpiece. The positioning of the tube 40 is such that the nozzle 18 accurately directs the cutting debris 20 in a selected direction.

[0017] Connected to the nozzle 18 is a proximate end 44 of gas hose 42. The proximate end 44 of the gas hose 42 can be connected to the nozzle 18 by a variety of different means that are well known in the art. Attached to a distal end 45 of the air hose can either be a suction device such as a vacuum, a blower device or a compressed gas source 43. In the embodiments including a blower device or compressed air source 43 connected to the distal end 45 of the hose 42, the nozzle 18 will emit a stream of gas or air, and will thus direct the cutting debris 20 in a selected direction by a blowing force. In the alternative embodiment including the suction device 43 connected to the nozzle 18 by way of the air hose 42, the nozzle 18 will act as a vacuum and suck the cutting debris 20 into the air hose 42. The cutting debris 20 is preferably deposited in a refuse bin (not shown) or suitable filtering device.

[0018] Referring to FIG. 2, the air hose 42 is disposed on a retractable coil device 46. The air hose 42 can be withdrawn from the retractable coil device 46 when the positionable member 16 and nozzle 18 rotate to a selected position 48 (shown by the dotted lines), and will automatically recoil back within the device 46 upon the positionable member 16 returning to an initial position 50. The retractable coil device 46 provides enough tension to keep the air hose 42 taut, ensuring that the air hose 42 will not become slack where it could be caught within a moving gear or become entangled with another device.

[0019] Additionally, it is preferable to include a channeled groove member 52 attached to the positionable member 16. The channeled groove member 52 is substantially the same diameter and shape of the positionable member 16. The channeled groove member 52 allows the air hose 42 to nest within its groove while the positionable member 16 rotates about the laser beam 14. One skilled in the art will immediately recognize that it is also within the scope of the present invention to include a channeled groove on the positionable member itself for which to nest the air hose 42.

[0020] In operation, the workpiece 22 to be cut or ablated is placed upon the worktable 26 in a position suitable for the laser beam 14 to appropriately ablate a desired pattern. Upon ablating the workpiece 22 and cutting the desired pattern, the laser beam 14 separates the workpiece 22 into a first preferred portion 54 and a second scrap portion 56. The preferred portion 54 of the workpiece 22 is the portion that is desired upon cutting the selected pattern. The scrap portion 56 of the workpiece 22 is the portion or portions which are not included within the selected pattern, and will in most cases either be discarded, reused in another application, or recycled.

[0021] The positionable member 16 and nozzle 18 are initially held at the initial position 50, as illustrated in FIG. 2. When the laser device 12 is activated, emitting the laser beam 14, the X-Y directional worktable 26 travels in a selected pattern, which may include the worktable 26 traveling in a multi-directional relation. When traveling in a multi-directional relation, the direction at which the workpiece travels in relation to the laser beam varies. The multi-directional relation includes, but is not limited to, the pattern of the preferred portion having a line changing direction such as at a corner, a curve with either an increasing or decreasing radius, a curve having an inflection point, or any combination thereof. The laser beam 14 ablates the workpiece 22 as the worktable 26 travels, and thus places the workpiece 22 in the direct path of the laser beam 14, which in turn ablates the workpiece 22 with the corresponding selected pattern. This selected pattern is preferably programmed in a programmable logic controller (PLC) which controls the movement of the X-Y directional table 26, along with activating the laser device 12.

[0022] The PLC is also programmed and integrated with the positionable member 16 to selectively position the nozzle 18 to direct the cutting debris 20 away from the preferred portion 54 of the workpiece 22. The PLC controls the drive means 38 to rotate in a specific direction. The electrical motor 38 is mechanically operable with the positionable member 16. The geared portion 32 is attached to the positionable member 16 and mateably engages the gear 34 attached to the drive means 38. Upon activating the drive means 38, the positionable member 16 rotates in the selected direction, indicated by arrows A and B as illustrated in FIG. 2. When the positionable member 16 rotates in the direction indicated by arrow A, the tube 40 of the nozzle 18 rotates about the laser beam 14 in a direction of A′. When the positionable member 16 rotates in a direction indicated by arrow B, the tube 40 of the nozzle 18 rotates about the laser beam 14 in a direction indicated by arrow B′. Referring again to FIG. 2, the dotted lines indicate a selected position 48 of the nozzle 18 and tube 40 as the positionable member 16 travels in the direction indicated by arrow B, the tube 40 of the nozzle 18 and thus travels in the direction indicated by arrow B′.

[0023] In either embodiment of the present invention, the PLC is programmed to synchronize the rotation of the positionable member 16 with that of the traveling direction of the worktable 26. At all times the tube 40 of the nozzle 18 is positioned to direct the cutting debris 20 away from the preferred portion 54 of the workpiece 26.

[0024] In the embodiment of the present invention including either the blower device or compressed air source connected to the air hose 42, the PLC is programmed to position the positionable member 16 such that the tube 40 of the nozzle 18 is positioned in a substantially orthogonal relation to the immediate direction at which the worktable 26 is traveling to direct the cutting debris 20 away from the preferred portion 54 of the workpiece 26 and towards the scrap portion 56 by blowing the cutting debris 20.

[0025] In the embodiment of the present invention including the suction device connected to the air hose 42, the PLC is programmed to position the positionable member 16 such that the tube 40 of the nozzle 18 is positioned in a substantially orthogonal relation to the immediate direction at which the worktable 26 is traveling to direct the cutting debris 20 away from the preferred portion 54 of the workpiece 22 by drawing the debris 20 into the tube 40.

[0026] FIGS. 4 and 5 illustrate alternative embodiments of the present invention. In each alternative embodiment, instead of a nozzle rotating about the laser beam, a plurality of stationary nozzles 60 are positioned to selectively direct cutting debris 20 away from the preferred portion 54 of the workpiece 22. Each nozzle 60 is attached to a stationery member 61, which is attached to the bracket 24.

[0027] Preferably, each nozzle 60 includes a valve device 62 actuated by the PLC to open or close, either blocking or allowing a stream of air to pass through each nozzle 60, and thus directing the cutting debris 20 in the direction the actuated valve 62 and cooperating nozzle 60 are directed, depending upon whether the air source is a vacuum or a blower device. The PLC is programmed to open the appropriate nozzle 60 depending on the position of the preferred portion 54 of the workpiece 22 in relation to the scrap portion 56. Each valve 60 is electrically connected to the PLC via a wiring schematic 70 as is well known in the art.

[0028] The additional alternative embodiments preferably include a circular conduit 64 connected to an air source via a connecting hose 66. The circular conduit 64 is connected to each actuating valve device 62, thus allowing a constant pressure (or vacuum) of air at each valve 62. However, it would also be within the scope of the present invention to provide a separate hose (not shown) for each nozzle 60, and connecting each hose to a central actuating valve controlled by the PLC, thus eliminating the need to provide a valve 62 at each nozzle 60.

[0029] FIGS. 4 illustrates an exemplary additional embodiment of the present invention comprising two nozzles 60 being able to direct cutting debris 20 in two directions. FIG. 5 illustrates another exemplary additional embodiment of the present invention comprising three nozzles 60 being able to direct cutting debris 20 in three directions. However, it should be understood by those skilled in the art that it is within the scope of the present invention to include additional nozzles 60 to direct cutting debris 20 in various directions. Each added nozzle 60 will increase the number of directions the cutting debris 20 can be directed away from the preferred portion 54 of the workpiece 22.

[0030] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.

Claims

1. An apparatus to selectively direct cutting debris in selected directions wherein a laser beam separates a workpiece in a multi-directional relation, the apparatus comprising: a nozzle effective for pneumatically directing the cutting debris; a rotatable member, the nozzle attachable thereto; and a programmable logic controller integrated with the rotatable member to selectively position the direction of the nozzle.

2. The apparatus of claim 1 and further comprising a blower device, the nozzle connectable thereto.

3. The apparatus of claim 1 and further comprising a suction device, the nozzle connectable thereto.

4. The apparatus of claim 1 and further comprising an electrical motor mechanically operable with the rotatable member, the programmable logic controller actuating the motor.

5. An apparatus for positioning a nozzle to pneumatically direct cutting debris in a selected direction wherein a laser beam and a selected workpiece travel in a multi-directional relation to one another, a direction of the travel changing at least once, the apparatus comprising: a member positionable proximate the laser beam; the nozzle attachable to the positionable member; and a programmable logic controller integrated with the positionable member, selectively positioning the gas nozzle in synchronicity with the multi-directional travel of the workpiece in relation to the laser beam.

6. The apparatus of claim 5 and further comprising a blower device, the nozzle connectable thereto.

7. The apparatus of claim 5 and further comprising a suction device, the nozzle connectable thereto.

8. The apparatus of claim 5 wherein the maneuverable member is rotatably positionable about the cutting source.

9. The apparatus of claim 5 wherein the laser beam separates the workpiece into a first portion and a second portion, the nozzle synchronously positionable to direct the cutting debris away from the first portion.

10. An apparatus for selectively positioning a nozzle to pneumatically direct laser cutting debris from a workpiece in a selected direction, the apparatus comprising: a laser emitting device positionable proximate the workpiece; a positioning member positioned proximate and rotatable about the laser emitting device and the gas nozzle being attachable to the positioning member, the gas nozzle thus rotatable about the cutting device to pneumatically direct cutting debris from the workpiece in the selected direction.

11. The apparatus of claim 10 and further comprising a compressed gas source, the nozzle connectable thereto.

12. The apparatus of claim 10 and further comprising a blower device, the gas nozzle connectable thereto.

13. The apparatus of claim 10 and further comprising a suction device, the gas nozzle connectable thereto.

14. The apparatus of claim 10 and further comprising a programmable logic controller integrating the selected direction of the gas nozzle in conjunction with a workpiece feed direction in relation to the laser emitting device.

15. The apparatus of claim 14 and further comprising a motor operably connected to the positioning member, the motor for rotatably positioning the positioning member and selectively positioning the gas nozzle, the programmable logic controller actuating the motor.

16. An apparatus to selectively direct laser cutting debris away from a preferred portion of a workpiece, the apparatus comprising: a laser emitting device positioned proximate the workpiece; a positioning member proximately positionable about the laser device; a nozzle attachable to the positioning device, the nozzle capable of directing cutting debris away from the preferred portion of the workpiece; and a programmable logic controller (PLC), the PLC integrated with the positioning member to selectively position the nozzle in relation to the cutting device and the preferred portion of the workpiece.

17. The apparatus of claim 16 and further comprising a suction device, the nozzle connectable thereto.

18. The apparatus of claim 16 and further comprising a blower device the nozzle connectable thereto.

19. The apparatus of claim 16 and further comprising: a rotatable member, the nozzle attachable thereto; and a motor operably connected to the rotatable member, the motor controlled by the PLC to maneuver the rotatable member selectively positioning the nozzle.

20. The apparatus of claim 16 wherein the motor and the rotatable member each include mateably engageable gear portions.

21. An apparatus to selectively position a gas stream for pneumatically directing cutting debris away from a preferred portion of a workpiece, the workpiece being cut by a laser beam, the selected position of the gas stream defined as a function of a varying feed direction of the workpiece in relation to the laser beam, wherein the varying feed direction varies at least once.

22. The apparatus of claim 21 comprising: a maneuverable member positionable proximate the laser beam; a nozzle attachable to the maneuverable member; and a programmable logic controller integrated with the maneuverable member, selectively positioning the gas nozzle in synchronicity with the varying feed direction of the workpiece in relation to the laser beam.

23. The apparatus of claim 21 comprising: a stationary member positioned proximate the laser beam; a plurality of nozzles fixedly attachable to the stationary member; a valve to control the flow of air through each nozzle; a programmable logic controller integrated with the valve to selectively direct cutting debris in synchronicity with the varying feed direction of the workpiece in relation to the laser beam.