U.S. patent application number 10/099201 was filed with the patent office on 2002-09-19 for debris removal apparatus for use in laser ablation.
Invention is credited to Lawson, William E..
Application Number | 20020130116 10/099201 |
Document ID | / |
Family ID | 25191962 |
Filed Date | 2002-09-19 |
United States Patent
Application |
20020130116 |
Kind Code |
A1 |
Lawson, William E. |
September 19, 2002 |
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.
Inventors: |
Lawson, William E.;
(Somerset, WI) |
Correspondence
Address: |
KINNEY & LANGE, P.A.
THE KINNEY & LANGE BUILDING
312 SOUTH THIRD STREET
MINNEAPOLIS
MN
55415-1002
US
|
Family ID: |
25191962 |
Appl. No.: |
10/099201 |
Filed: |
March 13, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10099201 |
Mar 13, 2002 |
|
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09805583 |
Mar 13, 2001 |
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Current U.S.
Class: |
219/121.84 ;
219/121.67 |
Current CPC
Class: |
B23K 26/142 20151001;
B23K 26/147 20130101; B23K 26/1438 20151001 |
Class at
Publication: |
219/121.84 ;
219/121.67 |
International
Class: |
B23K 026/14; B23K
026/38 |
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.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This is a continuation-in-part application of application
Ser. No. 09/805,583 filed Mar. 13, 2001.
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.
* * * * *