Metal cutting machine with cut piece pickup and transport magnets

A metal cutting machine has a plurality of tool carrying cutting heads mounted for movement along a bridge which in turn is mounted on rails or the like for movement transverse to the direction of head movement. Controls are provided for selective movement of the heads and bridge. A bridge-mounted plurality of magnet assemblies are provided which, after one or more cut pieces have been formed from a plate-like workpiece by the heads, are actuated to engage the cut pieces and raise them from the remaining skeletal workpiece. The bridge on which the magnet assemblies are mounted is movable to a position remote from the workpiece so that the magnets can deposit the cut pieces at a receiving point. The assemblies may be mounted on the same bridge as the cutting heads and connected to the latter for selective horizontal positioning by the same controls used for cutting. Alternately, the assemblies may be mounted on a separate bridge disposed on the same rails.

U.S. PRIOR ART OF INTEREST 
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Inventor U.S. Pat. Nos. 
Issue Date 
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Clark 675,323 May 28, 1901 
Kohlhafer et al 
2,363,007 Nov. 21, 1944 
Birchall 2,729,344 Jan. 3, 1956 
Hill 2,856,157 Dec. 24, 1974 
Hooper 3,866,892 Feb. 18, 1975 
Hooper 4,012,027 March 15, 1977 
Itani et al 4,139,180 Feb. 13, 1979 
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BACKGROUND AND SUMMARY OF THE INVENTION 
This invention relates to a metal cutting machine with cut piece pickup and 
transport magnets. 
Metal cutting machines using flame cutting torches or the like have long 
been known for cutting a plurality of relatively small pieces from a large 
metal plate. See, for example, U.S. Pat. Nos. 3,866,892 and 4,012,027. 
Such machines may utilize the well-known numerical control, photoelectric 
tracers and the like for controlling the movement of the cutting heads. 
Subsequent to cutting, the cut pieces must be removed from the plate and 
transported to another location. 
The cut pieces are usually of very heavy steel and may range in weight from 
about 4-5 pounds to several hundred pounds each. The pieces are usually 
too heavy for an operator to manually handle. 
It is known to remove cut pieces one-at-a-time from the skeletal plate by 
use of an overhead crane from which an electromagnet is suspended. The 
U.S. Pat. No. 675,323 is illustrative of a crane type magnetic device. 
It is furthermore known to utilize an electromagnet in a metal cutting 
machine for holding a part of a workpiece in place while a torch cuts the 
piece out by moving around the periphery of the magnet, as in U.S. Pat. 
No. 2,363,007. 
Additionally, it is known to use electromagnets for picking up and 
transporting large metal objects in breaking up large ships and the like, 
as in U.S. Pat. No. 4,139,180. Furthermore, magnets are used for transport 
of stacks of cans, as in U.S. Pat. No. 2,729,344, and in other material 
handling devices such as in U.S. Pat. No. 3,856,157. 
It is a task of the present invention to provide a multiple-piece type 
metal cutting machine having thereon a simple, yet effective means for 
removing one or a plurality of previously cut pieces from the skeletal 
workpiece and for transporting the pieces to a suitable receiving station. 
It is a further task of the invention to provide selectivity as to which 
cut piece or pieces are to be handled at any given time in the overall 
process of removing all the cut pieces from the skeletal workpiece. 
The invention is contemplated for use in a metal cutting machine having a 
plurality of tool carrying cutting heads mounted for movement along a 
bridge which in turn is mounted on rails or the like for movement 
transverse to the direction of head movement. Controls are provided for 
selective movement of the heads and bridge. 
A bridge-mounted plurality of magnet assemblies are provided which, after 
one or more cut pieces have been formed from a plate-like workpiece by the 
heads, are actuated to engage the cut pieces and raise them from the 
remaining skeletal workpiece. The bridge on which the magnet assemblies 
are mounted is movable to a position remote from the workpiece so that the 
magnets can deposit the cut pieces at a receiving point. 
It is contemplated that the assemblies may be mounted on the same bridge as 
the cutting heads and connected to the latter for selective horizontal 
positioning by the same controls used for cutting. Alternately, the 
assemblies may be mounted on a separate bridge disposed on the same rails.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The preferred embodiment incorporating the concepts of the invention is 
illustrated in FIGS. 1-3 wherein a metal cutting machine 1 is adapted to 
be mounted on a pair of longitudinal support rails 2 and 3 which are 
secured to the floor. Support gantries 4 and 5 are mounted for movement 
along the respective rails, with the gantries supporting the ends of a 
transverse support or bridge 6 which normally extends over the cutting 
area. A plurality of carriages 7a, 7b and 7c are suitably mounted for 
movement along bridge 6. 
Bridge 6 is adapted to be driven along support rails 2, 3 by any suitable 
motive means such as motor 8 which is mounted in gantry 5 and which has a 
pinion 9 which meshes with a rack 10 disposed along rail 3. Support gantry 
4 contains similar motive means (not shown) to insure even and parallel 
movement of the gantries. 
Similarly, carriage 7a is adapted to be driven along bridge 6 by any 
suitable motive means such as a motor 11 on the carriage which has a 
pinion 12 which meshes with a rack 13 disposed on the bridge. Carriage 7a 
is designated the master carriage and is permanently secured to an endless 
movable band 14. Carriages 7b and 7c are designated as slave carriages and 
are selectively engaged with movable band 14 to vary the spacing between 
the carriages. 
An input control programming device is provided to control the operation of 
motors 8 and 11, the engagement of slave carriages 7b and 7c with band 14 
and other elements to be described. The device may be of any desired 
well-known type such as a photoelectric tracer, but in the present 
embodiment is shown as a numerical control system. As shown schematically 
in FIG. 1, an input control unit 15 is used to program and operate the 
numerical control equipment, which includes paper or magnetic tape 16 
which passes through the usual pickup head section 17 to create an output 
for driving the aforesaid motors through suitable lines at a speed and in 
the direction desired to create programmed paths for carriages 7. 
Each carriage 7 mounts a cutting head 18 on its front side and which in 
this embodiment includes a flame cutting torch 19 supplied with 
electricity and gas from the usual sources, not shown. Torches 19 are 
adapted to be selectively actuated from input control unit 15 in the usual 
manner. Torches 19 are adapted to cut a flat plate-like metal workpiece 20 
mounted on a supporting table 21. 
In the present instance, input control unit 15 is programmed to operate the 
machine so that torches 19 will cut a plurality of small individual pieces 
22 from workpiece 20. The pieces may all be identical, but FIG. 1 
illustrates them as in multiple transverse rows of different shape, namely 
triangles 22a, circles 22b and rectangles 22c. Since slave carriages 7b 
and 7c follow the same path as master carriage 7a, all the pieces in one 
row must be of the same shape. 
It is contemplated that machine 1 incorporates means for selectively 
removing the cut pieces 22 from workpiece 20 and transporting them to a 
receiving station remote from the workpiece. In the present embodiment, 
the receiving station 23 is disposed between rails 2 and 3 and adjacent 
one end of table 21. Station 23 may comprise the floor or otherwise 
holding means for cut pieces 22. In view of the multiple shapes involved 
with the present embodiment, the holding means is shown as comprising a 
plurality of bins 24a, 24b, 24c for respectively receiving the separate 
cut pieces 22a, 22b and 22c. 
The removing and transporting means comprises, in the present embodiment, a 
magnet assembly 25 mounted on the rear side of each carriage 7a-7c and 
thus connected to its respective cutting head 18 for movement therewith 
along bridge 6. Each magnet assembly 25 comprises, as best shown in FIGS. 
2 and 3, an electromagnet 26 connected via suitable wires 27 to a source 
of electricity, which can be selectively actuated by input control 15. 
Each magnet 26 is disposed for vertical movement relative to workpiece 20. 
For this purpose, the magnet is mounted to the piston rod 28 of a suitable 
motive means such as pneumatic or hydraulic cylinder 29 having lines 30 
connected to a valved pressure fluid source, not shown, which is adapted 
to be actuated by input control unit 15. 
Cylinder 29 is secured to the rear side of the respective carriage 7a-7c by 
suitable clamps 31. 
Referring particularly to FIGS. 2 and 4a, when the pieces 22 are being 
flame cut from workpiece 20, torch 19 is in the down position adjacent the 
workpiece, while electromagnets 26 on the side of brdige 6 remote from the 
torches are retracted and inoperative. Once the cut pieces have been 
formed as in FIG. 1, and referring particularly to FIG. 3, torches 19 are 
retracted. Then, and in accordance with the particular program of input 
control unit 15, at least one electromagnet 26 is lowered into engagement 
with a cut piece 22 and after the piece is magnetically clamped thereto by 
actuation of the magnet, the magnet is raised upwardly away from workpiece 
20. See also FIG. 4b. 
Although one individual cut piece 22 could be removed and transported from 
workpiece 20 at a time, it is expected that a multiplicity of pieces will 
be removed, in any sequence desired. The programmed control can cause 
transport of a plurality of cut pieces to a receiving station 23, all at 
one time, where they can be simultaneously released. However, in the 
showing of FIG. 1 and FIGS. 4a-4e it is contemplated that only square cut 
pieces 22c are to be handled during one cycle of operation, leaving the 
remaining pieces 22a and 22b for later. 
For this purpose, after pickup, motor 8 is actuated to move bridge 6 so 
that it is in the position shown in phantom in FIG. 1, that is, remote 
from table 21 and above station 23. The program also actuates motors 11 to 
bring the left bridge-mounted magnet assembly 25 over square piece bin 
24c, where its piece 22c is released to drop into the bin, as shown in 
FIG. 4c. The program then engages carriage 7b with moving band 14 so that 
center assembly 25 moves over bin 24c and drops its piece, as in FIG. 4d. 
And finally, the same thing occurs with carriage 7c and right assembly 25, 
as shown in FIG. 4e. 
Motors 8 and 11 are then actuated to return bridge 6 and assemblies 25 to 
over the now skeletal workpiece 19 for the next cycle of piece removal. 
The system is very flexible in operation. For example, if it is desired to 
deposit one of each shape of cut piece 22 at station 23 simultaneously, 
left magnet assembly 25 could pick up left triangle 22a, middle assembly 
25 could pickup middle circle 22b and right assembly 25 could pick up 
right rectangle 22c. Bridge 6 could then be moved over station 23 and all 
three cut pieces could be deposited at once into their respective bins 
24a,b,c. 
FIGS. 1-3 illustrate an embodiment wherein the bridge-mounted magnet 
assemblies 25 are disposed on the same bridge as cutting heads 18 so that 
they are fixedly connected together through their respective mounting 
carriages 7a-7c. Thus they can share a common positioning control. 
However, in some instances it may be desirable for assemblies 25 to be 
mounted on a similar secondary bridge 32 which is spaced from and parallel 
to the main torch carrying bridge 6. See FIG. 5. In this instance, 
additional controlling functions would be necessary. 
It may also be desirable to mount magnet assemblies 25 on bridge 6 or 32 in 
such a way that once adjusted for proper spacing they could be locked into 
position. Such would be the case when pieces of only one shape were being 
cut from workpiece 20, thus eliminating the need for horizontal movement 
of magnet assemblies 25 along the bridge. 
Furthermore, while the selective operation of the device is preferably of 
the programmed automatic type, at least part of the cycle (such as cut 
piece pickup, transfer and deposit) may be manually controlled, as by 
control switches 33 on the face of unit 15. 
The concepts of the invention provide a unique system of removing small 
pieces cut from a metal workpiece and transporting them to a desired 
location. By utilizing portions of the cutting machine itself, significant 
economies are obtained. 
Various modes of carrying out the invention are contemplated as being 
within the scope of the following claims particularly pointing out and 
distinctly claiming the subject matter which is regarded as the invention.