Note: Descriptions are shown in the official language in which they were submitted.
CA 02411633 2002-11-12
LASER CUTTING PLATE CONVEYOR
FIELD OF THE INVENTION
The present invention relates to a storage and retrieval system capable of
horizontal and vertical movement components to operably engage relatively
large
planar sheets of material from a plurality of vertically spaced storage
locations for
delivery to one or more workstations, such as a laser cutting workstation.
BACKGROUND OF THE INVENTION
Laser cutting workstations come in a variety of styles, sizes, and shapes from
a
wide variety of commercial manufacturers. Each laser machining cell is
typically
supplied with a stream of workpieces to be processed by a conveyor system.
Typical
conveyor systems for laser machining workstations can be seen in U.S. Patent
No.
5,192,848; U.S. Patent No. 5,310,396; LT.S. Patent No. 5,121,539; U.S. Patent
No.
4,735,539; and commercially available units are manufactured by Trumpf GmbH &
Co, Ditzingen, of the Federal Republic of Germany.
Most of these configurations require complicated shuttle systems to move parts
from vertical spaced storage locations to a ready position to be engaged by
the
conveyor system, since the conveyor system is incapable of operably engaging
and
removing the workpieces from the vertical storage locations directly.
SUMMARY OF THE INVENTION
It would be desirable in the present invention to provide a workpiece conveyor
system capable of operably directly engaging relatively large planar
workpieces
within vertically extending spaced storage locations or racks, and for moving
the
workpieces or plates from the storage location to a workstation with a single
conveyor system. It would be desirable in the present invention to eliminate
the need
for any intermediate shuttle or auxiliary movable elements to bring the
workpieces
into a ready position for attachment by the conveyor system. In other words,
it would
be desirable in the present invention to have the workpieces stored in a
vertically
extending spaced rack system where the storage location of each workpiece is a
ready
position that can be accessed directly by the conveyor system for operably
engaging
and moving the workpiece from the particular storage location to the
workstation for
processing.
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A superstructure includes columns supporting an overhead runway system
similar to a conventional bridge crane structure. The shelving is constructed
in a
manner that accommodates the carriage. The carriage arms are equally spaced to
go
in between the shelf supports. Once the carriage has been positioned into the
shelf
unit the carriage is then lowered down to the material. The suction cups that
are
attached to the carnage are then activated by a vacuum pump and attach
themselves
to the process sheets. The material being processed is raised, and then
transferred to
the laser bed. The trolley travels left or right to position the material over
the laser
bed. The sheet steel is then lowered onto the laser bed. A column on the
trolley
serves as a guide to raise and lower the carriage. The column stabilizes the
carnage
load; the column and carnage are offset from the trolley to evenly distribute
the
carried load. The carriage is raised and lowered by nylon and/or polyester
straps that
are rolled onto a drum. The carnage travels vertically to allow the hoist to
access
multiple shelves. Since the equipment travels on a runway system that is
expandable,
it is capable of supplying one or more lasers (or other processing machines).
The vacuum carriage goes into the shelves to retrieve sheets with other
systems, sheets are transferred from the rack out to the carriage versus the
carriage
retrieving the sheets while in the rack. The carriage can access multiple
shelves. The
fixed shelves are spaced to accommodate the vacuum carnage. The carriage is
raised
and lowered via nylon, and/or polyester straps which are rolled onto a drum.
Six (6)
directions of travel, forward, backward, left, right, up and down are provided
by the
combination of the shuttle/trolley and carnage. A series of vacuum cups are
used to
hold the product (sheets) as it travels from the shelves to the laser bed. A
remote
control station controls the apparatus.
The runway is the superstructure that supports the bridge similar to a
conventional overhead bridge crane superstructure. The bride is the structure
that
travels along the runway, and also supports the trolley. The trolley is the
structure
that travels horizontally along the bridge and supports the carriage. The
carriage is
the structure that travels vertically on the column of the trolley, which
supports a
series of vacuum cups. The vacuum cups are rubber type suction cups that
adhere to
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any flat surface such as sheets of steel, glass, plastic, etc. The shelves are
a series of
sheet storage shelves where the raw material (sheets) are stored for
processing.
Other applications of the present invention will become apparent to those
skilled in the art when the following description of the best mode
contemplated for
practicing the invention is read in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The description herein makes reference to the accompanying drawings wherein
like reference numerals refer to like parts throughout the several views, and
wherein:
Fig. 1 is a perspective view of a conveyor according to the present invention;
Fig. 2 is a perspective view of a photograph of a conveyor according to the
present invention with the workpiece support members positioned within the
vertically spaced storage system for retrieving a workpiece to be transported;
and
Fig. 3 is a close-up perspective view of the conveyor according to the present
invention illustrated in Fig. 2 prior to attachment to the workpiece for
transport.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Figs. 1-3, a laser cutter plate conveyor 10 according to the
present
invention includes a frame structure 12. The frame structure 12 can include at
least
one, and preferably two spaced apart, horizontally extending frame members or
rails
14. A trolley or shuttle 16 is supported on the frame members or rails 14 for
movement along a fixed path of travel defined by the frame members or rails
14.
Drive means 18 is provided operably connected to the shuttle 16 for moving the
shuttle 16 between first and second end limits of travel along the
horizontally
extending frame member or rail 14. By way of example and limitation, the drive
means 18 can include a reversible electric motor 20 for driving the shuttle 16
between the first and second end limits of travel along the fixed path defined
by the
horizontally extending frame member or rail 14. Control means 22 can be
provided
operably connected to the drive means 18 of the shuttle 16 for controlling
movement
of the shuttle 16 along the fixed path of travel defined by the horizontally
extending
frame member or rail 14. Appropriate signal generators, such as switches or
sensors,
can be provided as required along the fixed path of travel for indicating the
location
of the shuttle 16 as the shuttle 16 moves along the fixed path allowing the
control
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means 22 to control the speed and the position of the shuttle 16 along the
fixed path
of travel for stopping at either the first or second end limit of travel, or
any
workstation defined in between the end limits of travel.
The shuttle 16 includes at least one vertically extending support member 24.
A carriage 26 is supported for movement along the vertically extending support
member 24. Lift means 28 is provided for moving the carnage 26 vertically
along
the vertically extending support member 24 between a lowest position and a
highest
position. The lift means 28 can include one or more nylon or polyester straps
or belts
extendable and retractable with respect to a drum or spool with a reversible
drive
motor controlled by the control means 22. Appropriate signal generators, such
as
sensors or switches, can be provided for identifying various vertical
positions along
the vertically extending support member 24 allowing the control means 22 to
control
the speed and position of the carriage 26 as the carriage 26 moves along the
vertical
path defined by the vertically extending support member 24. The carnage 26 can
include a plurality of horizontally extending support members 30. A plurality
of
workpiece engaging members 32 are connected to the horizontally extending
support
members 30. The workpiece engaging members 32 can be of any known
configuration suitable for lifting relatively large, heavy, metal plates. By
way of
example and not limitation, the workpiece engaging members 32 can include
magnetic and/or vacuum suction cup forms of engagement members. The magnetic
and/or vacuum actuation can be controlled in response to appropriate signals
from
the control means 22 in order to engage and lift a workpiece from the
vertically
extending storage rack 34 for movement along the fixed path of travel to the
workpiece bed or support nest 36 of the laser cutting apparatus.
In the illustrated embodiment, the vertically extending storage rack 34 can be
connected to and form part of the frame structure 12. The storage rack 34 can
include a plurality of vertically spaced shelves 38. Each shelf 38 can support
a
vertical stack of workpieces to be processed as best seen in Fig. 3. Each
shelf 38 is
defined by a plurality of horizontally spaced shelf members 40. The
horizontally
shelf members 40 define openings in between one another at the ends facing the
side
of approach by the carriage and associated plurality of horizontally extending
support
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members 30. The spacing defined by the horizontal shelf members 40 is
complementary allowing entry of the horizontally extending support members 30
of
the carriage 26 permitting direct engagement with the upper-most workpiece in
the
stack supported on that particular shelf as best seen in Fig. 3. This
complementary
configuration eliminates the need for additional shuttle units to move each
individual
plate from the storage location to a position accessible by the overhead
conveyor
system. In operation, the vertically extending storage rack 34 is loaded with
workpieces to be processed. The shelves can support a stack of identical
workpieces
on each shelf, or each shelf can be allocated a workpiece of a particular
material or
thickness to be processed. The particular location of the workpiece to be
processed
can be programmed into the control means 22. When the laser cutting apparatus
calls
for a new workpiece to be processed, the control means 22 determines the shelf
location of the appropriate workpiece to be retrieved, and moves the carriage
26 to
the appropriate elevation for entry above the shelf unit containing the
workpiece to be
retrieved. After the appropriate elevation of the carriage 26 has been set, or
simultaneously while moving the carriage 26, the shuttle 16 can be activated
to move
from the present or current position toward the vertical storage rack 34. If
necessary,
the shuttle 16 can be stopped prior to entering into the vertical storage rack
34 if the
carriage 26 has not reached the appropriate elevation for entry into the shelf
holding
the workpiece to be retrieved. When the carriage 26 is in the appropriate
elevation to
enter the shelf supporting the workpiece to be retrieved, the shuttle 16
continues
toward the storage rack 34 inserting the horizontally extending support
members 30
within the complementary open spaces of the horizontally spaced shelf members
40.
When fully inserted, the carriage 26 is lowered into engagement with the upper-
most
workpiece supported on the shelf in response to appropriate signals by the
control
means 22. The control means 22, then activates the engaging members 32 to
attach
to the workpiece to be transferred. The carnage 26 is then raised slightly to
lift the
engaged workpiece from the stack supported by the shelf and the shuttle 16 is
then
sequentially, or simultaneously, moved along the fixed path of travel defined
by the
horizontally extending frame members or rails 14 of the frame structure 12.
After
reaching the laser cutter workstation position, the shuttle unit 16 is stopped
in
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response to appropriate signals from the control means 22. The carnage 26 is
then
actuated to lower the engaged workpiece to the workpiece bed or support nest
36 of
the laser cutter apparatus. After the workpiece is engaged with the workpiece
bed or
support nest 36, the control means 22 sends the appropriate signal to
disengage the
engaging members 32, ending the transport cycle. The carnage is then moved
vertically away from the workpiece that has been transported, and sequentially
or
simultaneously, the shuttle 16 is operated to remove the conveyor away from
the
laser cutter workstation allowing the processing to begin.
While the invention has been described in connection with what is presently
considered to be the most practical and preferred embodiment, it is to be
understood
that the invention is not to be limited to the disclosed embodiments but, on
the
contrary, is intended to cover various modifications and equivalent
arrangements
included within the spirit and scope of the appended claims, which scope is to
be
accorded the broadest interpretation so as to encompass all such modifications
and
equivalent structures as is permitted under the law.
