Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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PROTECTION SYSTEM FOR LASER CUTTING MACHINE
FIELD OF THE INVENTION
[0001] The present invention relates generally to a protection system and more
particularly, to a protection system for a laser cutting machine.
BACKGROUND OF THE INVENTION
[0002] Laser cutting is a technology that uses a laser to cut materials, and
is typically
used for industrial manufacturing applications. Laser cutting works by
directing the
output of a high-power laser most commonly through optics. A laser cutting
machine
features a cutting head generating a laser beam that moves in both of the
horizontal
dimensions over a workpiece loading onto a table. The focused laser beam is
directed to
the workpiece, part of which is then melted, burns, and vaporizes away. A cut
edge
with a high quality surface finish is therefore created.
[0003] Lasers enclosed in the laser cutting machines are capable of emitting
high levels
of energy and can therefore be dangerous to the eyes and skin of its operator.
The use of
the laser cutting machine can also impose a number of hazards including toxic
gases
and fumes and inhalable particles. Moreover, the possible random reflection of
the laser
light may burn the retina of an operator when the laser initially pierces the
workpiece.
Therefore, coupling a protective enclosure apparatus to a laser cutting
machine is
essential to the safe operation of the machine.
[0004] Most existing protective enclosures cover the entire laser cutting
machine and
thereby form a chamber. This not only results in a bulky machine, but also
requires a
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pallet shuttle system to be installed onto the laser cutting machine for
loading and
unloading the workpiece into the chamber. This solution drives up the
financial cost as
well as the operation time of the laser cutting machine.
[0005] There therefore exists a need within the industry for the ability to
increase the
effectiveness of a protection system for the laser cutting machine, while
avoiding the
abovementioned drawbacks of known protective enclosure apparatuses.
SUMMARY OF THE INVENTION
[0006] With the forgoing concerns and needs in mind, it is the general object
of the
present invention to provide a protection system.
[0007] It is another object of the present invention to provide a protection
system for a
laser cutting machine.
[0008] It is another object of the present invention to provide a protection
system for a
laser cutting machine that permits the operator of the laser cutting machine
to directly
load and unload the workpiece onto and off the table without having to wait
for the
pallet shuttle exit a typical protective enclosure apparatus.
[0009] It is another object of the present invention to provide a protection
system for a
laser cutting machine that allows the coil feeding of the workpiece directly
onto the
table at a reasonable financial cost.
[0010] It is another object of the present invention to provide a protection
system of a
laser cutting machine guard surround the laser torch head only and therefore
reduce
the overall volume of the laser cutting machine.
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[0011] These and other objectives of the present invention, and their
preferred
embodiments, shall become clear by consideration of the specification, claims
and
drawings taken as a whole.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present invention will be better understood from reading the
following
description of non-limiting embodiments, with reference to the attached
drawings,
wherein below:
[0013] Figure 1 illustrates a diagram of a prior art laser cutting machine,
according to
one embodiment of the present invention.
[0014] Figure 2 illustrate an isomeric, side view of a protection system,
according to one
embodiment of the present invention.
[0015] Figure 3 is an enlarged view of the protection system, shown in Figure
2,
according to one embodiment of the present invention.
[0016] Figure 4 illustrates the protection system of Figures 2 and 3 as a
middle
protection screen is detached from the protection system, according to one
embodiment
of the present invention.
[0017] Figure 5 illustrates an enlarged sectional view of a top brushes
assembly
according to one embodiment of the present invention.
[0018] Figure 6 illustrates an isomeric, side view of a top brushes assembly,
according to
one embodiment of the present invention.
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[0019] Figure 7 illustrates an isomeric, side view of a bottom brushes
assembly,
according to one embodiment of the present invention.
[0020] Figure 8 illustrate an enlarged sectional view of a bottom brushes
assembly,
according to one embodiment of the present invention.
[0021] Figure 9 illustrates a cut-away of the top and bottom portions of the
protective
enclosure according to one embodiment of the present invention.
[0022] Figure 10 shows an enlarged bottom portion of the protective enclosure,
according to one embodiment of the present invention.
[0023] Figure 10A is an enlarged, detailed cross-sectional view of area 10A of
Figure 10.
[0024] Figure 11 illustrates the brush cup assembly as removed from
integration with
the lower part of the protective enclosure, according to one embodiment of the
present
invention.
[0025] Figure 12 illustrates a safety switch, according to one embodiment of
the present
invention.
[0026] Figure 13 illustrates a close-up sectional view of the bottom
protection assembly,
according to one embodiment of the present invention.
[0027] Figure 14 illustrates a non-linear path, according to one embodiment of
the
present invention; and
[0028] Figure 15 illustrates a perspective view of the laser head assembly.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] Figure 1 illustrates an isomeric side view of a workpiece manipulation
apparatus
having a laser cutting machine, and its protective enclosure apparatus 100. A
cutting
laser (not shown) is positioned inside a protective enclosure apparatus 101. A
pallet
shuttle 102 locates in close association with the protective enclosure
apparatus 101. A
workpiece can be loaded and unloaded onto and off the pallet shuttle 102. The
pallet
shuttle 102 then carriers the loaded workpiece, enters into and exits the
protective
enclosure apparatus 101 through a protective enclosure apparatus enclosure
door 103.
In particular, to load and unload the workpiece to be processed by the laser
cutting
machine onto the pallet shuttle 102, the pallet shuttle 102 must exit the
protective
enclosure apparatus 101.
[0030] It will therefore be readily appreciated that known laser enclosures
require
enclosing the totality, or a great degree, of the workpiece manipulation
apparatus itself,
which is both expensive and cumbersome. When the workpiece and (preferably,
movable) platen upon which it is transported are both captured inside the
laser
enclosure, as with the known apparatus shown in Figure 1, efficiencies are
lost due to
excessive set-up time and expense, as well as making the workpiece and cutting
laser
largely inaccessible without undue stoppage and shutdown of the apparatus as a
whole.
[0031] Figure 2 illustrates an isomeric, side view of a protection system 10,
according to
one embodiment of the present invention. In particular, Figure 2 illustrates
the
protection system 10, as integrated with a laser torch head 80, a bridge 90
for
supporting the laser torch head, and a workpiece 91 being processed. As it
will be
appreciated, the laser torch head 80, the bridge 90 and the workpiece 91 are
only
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partially shown in Figure 2, so as to permit illustration of the protection
system itself,
and its preferred placement with respect to the bridge 90, the laser torch
head 80 and
the workpiece 91.
[0032] While the present invention is being described in connection with the
bridge 90
and the laser torch head 80 shown in Figure 2, it will be readily appreciated
by one of
ordinary skill in the art the present protection system 10 could be integrated
into any
laser cutting head, regardless of the specific type of the same, without
departing from
the broader aspects of the present invention.
[0033] As most clearly shown in Figure 2, the protection system 10 of the
present
invention is moveably mounted to the bridge 90 so as to move therealong. The
bridge
90 itself is adapted to move in a direction perpendicular to the moving
direction of the
protection system 10, so as to cut the workpiece 91, as desired. Additionally,
the
protection system 10 is designed such that the laser cutting head can be
mounted on a
motorized actuator inside the protection system 10 allowing the laser cutting
head to be
raised or lowered automatically for the purpose of focusing the laser beam or
to
accommodate slight variations in thickness of the material to be cut without
affecting
the position or downward force of the brush guard on the material being cut.
This
enclosed motorized actuator reduces the risk of accidental exposure of the
laser light.
[0034] The protection system 10 includes a frame 11, a top protection assembly
40, a
middle protection shield 20, and a bottom protection assembly 60, thereby
forming a
cavity where a laser torch head 80 locates, so as to prevent the escaping of
reflected
laser light when the laser torch head 80 cuts the workpiece 91.
[0035] As will be appreciated, and in stark contrast to the enclosure of the
apparatus
shown in Figure 1, it is an important aspect of the present invention that it
is only the
laser head 80 itself, which is enclosed by top, middle and bottom assemblies,
40, 20 and
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60 respectively. Thus, the protection system/enclosure of the present
invention does
not extend to the apparatus as a whole, nor does the enclosures encompass the
movable
platen upon which the workpiece is arranged.
[0036] Turning now to Figures 3 and 4, in combination, the middle protection
shield
assembly 20 of the protection system 10 is illustrated in more detail. A light
shield 23 is
a preferably semi-translucent laser safe shield, so as to permit the operator
of the laser
cutting machine having a view of the inside of the cavity of the protection
system 10,
meanwhile prevents the reflected laser light escaping from the cavity. The
light shield
includes a planetary gasket 24. The light shield 23 is removably fixed to the
frame 11 via
four interlock switches 22 embedded in the frame 11. In alternative
embodiments, the
middle protection shield assembly 20 is mounted on hinges or vertical slides
which are
in conjunction with latches, the planetary gasket 24, and safety interlock
switches 22, so
as to allow interlocked access to the laser head for maintenance while
preventing
exposure of the laser by an operator.
[0037] In particular, the present invention envisions that the light shield 23
is preferably
a Laservision P5P10 IR fiber laser safety window, for blocking various light
rays across
multiple spectrums, although other suitable shielding may be utilized without
departing from the broader aspects of the present invention.
[0038] It should be noted that the light shield 23 must be secured to the
frame 11 and
the interlock switches 22 must be in contact with the light shield 23 in order
for the laser
torch head 80 to start working. Indeed, the there are several safety switches
integrated
with the light shield 23, all of which must be actuated in order for the laser
head 80 to
be permitted to operate.
[0039] As shown, Figure 3 illustrates the middle protection shield 20 in an
enclosed
position. The light shield 23 is secured onto the frame 11 via four interlock
(safety)
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switches 22. The interlock switches are in a locked position and therefore
permits the
laser torch head 80 to start working. Figure 4, in contrast, illustrates the
middle
protection shield 20 in an opened position. The light shield 23 is removed
from the
frame 11. The interlock switches trip to an unlocked position upon the
detaching of the
light shield 23 from the frame 11. Therefore, the laser torch head 80 is
unable to start
working until the light shield 23 is secured to the frame 11 again.
[0040] The frame 11 is preferably welded so as to provide a continuous
housing,
thereby preventing radiation from escaping during operation of the laser head
80.
[0041] Figure 5 and 6, in combination, illustrate a sectional view of the top
protection
assembly 40. In one preferred embodiment, the top protection assembly 40
includes a
top support cover 41 having an opening, and at least brush assembly 44
positioned to
cover the opening of the top support cover 41. The brush assembly is connected
to the
top support cover 41 via a bracket 42.
[0042] The brush assembly 44 includes one pair of brush holders 45 which are
in
connection with the bracket 42, and a pair of brushes 46, each of which
comprises a
plurality of brush bristles. One end of the brush 46 is received by the brush
holder 45 in
a brush socket. Two brushes in a pair are positioned in an opposite direction
at the same
vertical level, so as to permit the other ends of the two brushes to be facing
and
contacting each other. Therefore, the brushes assembly 44 prevents the
reflected laser
light from escaping the cavity from the top protection assembly 40, meanwhile
permits
any electrical cable, light cable or power cable connected to the laser torch
head 80 to
pass through the top protection assembly 40 and enter into the cavity. The
cables
therefore can move upward and/or downward freely without congesting the top
protection assembly 40.
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[0043] It shall be noted that in a preferred embodiment, three layers of the
brushes
assembly 44 are arranged vertically and connected to the bracket 42. However,
any
number of layers can be used to optimize the protection effect of the top
protection
assembly 40.
[0044] The top protection assembly 40 is connected to the frame 11 via two
interlock
(safety) switches 48. The two interlock switches 48 are in a locked position
and permit
the laser 80 to start working once the top protection assembly 40 is correctly
fixed to the
frame. However, if the top protection assembly 40 is removed, the two
interlock
switches 48 trip to an unlocked position and therefore prevent the laser torch
head 80
from starting. In another embodiment, the top protection assembly 40 may
include a
solid assembly with the utilities passing through the guard assembly walls by
means of
bulkhead connectors and plugs, so as to enhance safety and/or provide a more
tightly
sealed chamber, which can be vented more effectively in the case of unpleasant
or toxic
fumes generated during the cutting process.
[0045] Figure 7 and 8, in combination, illustrate the bottom protection
assembly 60. The
bottom protection assembly 60 includes a bottom cover 61 having an opening to
permit
the laser torch head 80 extending therethrough and applying the laser light
onto the
workpiece 91 via a laser application tip unit 82. The bottom protection
assembly 60
further includes a bottom brushes cup assembly 65. The bottom cup assembly 65
is
arranged in a position relative to the opening on the bottom cover 61 so as to
permit the
operation of the laser torch head 80 on the workpiece 91.
[0046] The bottom brush cup assembly 65 includes a circular base 62 connected
to the
bottom cover 61 via two interlock switches 69. An opening in the center of the
circular
base 62 is matched with the opening on the bottom cover to permit the laser
torch head
extending therethrough. The circular base 62 has at least one socket in a
circular shape
for receiving an array of brushes 66 arranged in the same circular shape
surrounding
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the central opening on the circular base 62. The brushes 66 are attached to
the circular
base 62011 one end, and extend downward with the other end of the brushes 66
directly
contacting the workpiece 91 thereby ensures that the cavity of the protection
system 10
is enclosed when the laser torch head 80 is performing cutting function on the
workpiece 91.
[0047] As will be discussed in more detail later, the brushes 66 includes a
solid rubber
membrane 67(122) embedded between the bristles 68. It is yet another important
aspect
of the present invention that due to the specific use of the brushes 66 and
how these
bristles/brushes may be compressed to a degree, i.e., slightly bent, when in
contact with
a workpiece, the protection system 10 of the present invention effectively
prevents the
reflected laser light from escaping the cavity when the workpiece 91 moves in
a vertical
direction sporadically during the laser cutting process for the workpiece 91.
[0048] In one preferred embodiment, two arrays of brushes are arranged and
received
in two separate concentric circular sockets locate on the circular base.
However, it
should be noted that any number of array of brushes and the relevant receiving
circular
sockets can be arranged, so as to optimize the protection effect of the bottom
protection
assembly 60.
[0049] The circular base 62 is connected to the bottom cover 61 via two joints
and two
safety interlock switches 69. The two interlock switches 69 are in a locked
position and
permit the laser torch light 80 to start working once the bottom brushes cup
assembly 65
is correctly fixed to the bottom cover 61. However, if the bottom brushes cup
assembly
65 is removed, the two interlock switches 69 trip to an unlocked position and
therefore
prevent the laser torch head 80 from starting.
[0050] The safe operation of the laser head 80 is further increased by
arranging a senor
(unillustrated) in the area of the base 62, for the purposes of detecting
whether a
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workpiece is positioned adjacent the laser head 80. If the sensor does not
detect a
workpiece in the area adjacent to the laser head 80, the laser head 80 will
not be
permitted to operate. Preferably, the laser head 80 will be prevented from
operating if
the sensor does not detect a workpiece within approximately 1mm below the
laser head
80, although it will be readily appreciated that other distances may be
instead utilized
without departing from the broader aspects of the present invention.
[0051] Figure 9 illustrates a cut-away of the top and bottom portions of the
protective
enclosure 10. As shown in Figure 9, the light shield 23 and frame 11 interact
and are
sized and positioned such that there is an overlap, 100/102, between a raised
edge of
the frame 11 and the light shield 23, thus ensuring that extraneous light from
the laser
head 80 does not escape the protective enclosure 10.
[0052] Figure 10 shows an enlarged bottom portion of the protective enclosure
10, as
well as a sectional view of one of a pair of spring-loaded bush biasing
devices 108. As
illustrated in Figure 10, the bottom brush cup assembly 65 includes an upper
mounting
plate 110, which itself is releasably attached to a base mounting plate 112
that is
operatively attached to the pair of spring-loaded brush biasing devices 108.
[0053] As will be appreciated, the spring-loaded brush biasing devices 108
include
preferably an articulating ball joint 114 and a biasing spring/element 116.
The biasing
device 108 thereby act to allow the brush cup assembly 65 and integrated
bristles to tilt
freely while being constantly biased downwardly into contact with the
workpiece
below, thus accommodating and remaining in tight contact with the workpiece,
regardless of differences or irregularities in the workpieces contour and/or
slope.
The ball joint 114 may comprise a magnetically coupled design to permit the
brush
biasing devices 108 to separate cleanly without causing permanent damage to
the guard
assembly in the case of a hard collision. The presence of the two safety
interlock devices
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69 will ensure deactivation of the laser in the case of a collision and
subsequent
separation of the ball joint 114.
[0054] As will be appreciated, the brush cup assembly will incur wear during
use, and
as such, is a consumable part which must be inspected and replaced from time
to time.
For its part, Figure 11 illustrates the brush cup assembly as removed from
integration
with the lower part of the protective enclosure. As further shown in Figure
12, a safety
switch 120 may be integrated with the protective enclosure to detect the
presence of the
brush cup assembly 65. The safety switch 120 is preferably a compression limit
type
switch or coded RFID switch, and is sensitive enough to determine when the
bush cup
65 is not engaged or is improperly installed or becomes loose, although other
types of
sensors and switches may be utilized for this purpose without departing from
the
broader aspects of the present invention. If the safety switch 120 does not
detect the
existence and proper installation of the bush cup assembly 65, the laser head
80 would
be prohibited from operation.
[0055] As discussed previously, the protective enclosure of the present
invention
includes many features that make the safe operation of the laser head 80
possible.
Figure 13 illustrates a close-up sectional view of the bottom protection
assembly 60. As
shown in Figure 13, and in a preferred embodiment, the bush cup assembly 65
includes
two concentrically aligned brushes/brush rings 66, each of which includes a
solid
rubber membrane 122 embedded within each of the concentrically aligned brush
rings
66.
[0056] As will be appreciated, the bushes 66 themselves are formed from
material, such
as but not limited to rubber, that is both resiliently flexible as well as
being able to
maintain structural integrity even in high temperature environments. An
interior,
preferably fabric, liner 124 is disposed between the brushes 66 and the laser
head 80, in
order to protect the brushes from damage due to operation of the laser head
80. Figure
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14 shows the non-linear path 126 that light emanating from the laser head 80
must
follow, in order to escape the protective enclosure of the present invention.
[0057] As discussed previously, one important aspect of the present invention
is that the
laser head 80 is much more easily accessible than known devices, and this
additional
functionality is shown in Figure 15. As shown in Figure 15, the light shield
23 is
movably mounted to linear guides 128, which allow the light shield 23 to be
moved up
or down (to a raised, or lowered, position) for the quick adjustment of, e.g.,
the focus of
the cutting beam, or the like. A pair of proximity sensors 130 are therefore
utilized to
determine if and when the light shield is in its lowered position, and only
allows
operation of the laser head 80 if the sensors 130 agree that the light shield
is in the
proper, protective (lowered) position.
[0058] As will be appreciated from a review drawing figures 1-15 and their
associated
discussion, the present invention has developed a laser cutting apparatus for
the
manipulation of workpieces, preferably metal workpieces. However, in contrast
to
known devices, the present invention utilizes a protective enclosure about the
laser
head only, thereby leaving the majority of the apparatus open to inspection
and
manipulation, as necessary. Moreover, the present invention utilizes a series
of
integrated safety switches, any of which can cause the operation of the laser
head to be
halted or prohibited, should any of these safety switches indicate an unsafe
situation.
These safety switches can of course be integrated with a machine-stop button,
preferably in series, so as to make the operation of the laser head 80 as safe
as possible.
[0059] Although this invention has been shown and described with respect to
the
detailed embodiments thereof, it will be understood by those of skill 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, modifications
may be
made to adapt a particular situation or material to the teachings of the
invention
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without departing from the essential scope thereof. Therefore, it is intended
that the
invention not be limited to the particular embodiments disclosed in the above
detailed
description, but that the invention will include all embodiments falling
within the scope
of this disclosure.
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