U.S. patent number RE36,664 [Application Number 08/653,192] was granted by the patent office on 2000-04-18 for method and apparatus for automatically segmenting animal carcasses.
This patent grant is currently assigned to William H. O'Brien, Texas Beef Group. Invention is credited to James M. Malloy, William H. O'Brien.
United States Patent |
RE36,664 |
O'Brien , et al. |
April 18, 2000 |
Method and apparatus for automatically segmenting animal
carcasses
Abstract
Manually segmenting animal carcasses into primary cuts involves
an enormous amount of manual labor and attendant expense. However,
known automated systems for segmenting carcasses cannot match the
accuracy of expert butchers. The apparatus for segmenting animal
carcasses disclosed herein provides an imaging station having a
vision system that determines parameters of the interior and/or
exterior of the carcass. Using these parameters, a computer
determines a cutting path or a plurality of cutting paths for
segmenting the carcass. A mounting vehicle, which securely holds
the carcass, transports the carcass from the imaging station to a
cutting station. In the cutting station, electrically controlled
cutting implements, such as high-pressure water jets or lasers,
segment the carcass along the determined cutting path or paths.
Inventors: |
O'Brien; William H. (Amarillo,
TX), Malloy; James M. (Richmond, CA) |
Assignee: |
Texas Beef Group (Amarillo,
TX)
O'Brien; William H. (Amarillo, TX)
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Family
ID: |
27358200 |
Appl.
No.: |
08/653,192 |
Filed: |
May 24, 1996 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
888256 |
May 22, 1992 |
5205779 |
|
|
|
754527 |
Sep 4, 1991 |
|
|
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Reissue of: |
006831 |
Jan 21, 1993 |
05314375 |
May 24, 1994 |
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Current U.S.
Class: |
452/157;
452/149 |
Current CPC
Class: |
A22B
5/0005 (20130101); A22B 5/0029 (20130101); A22B
5/0041 (20130101); A22B 5/20 (20130101) |
Current International
Class: |
A22B
5/00 (20060101); A22B 5/20 (20060101); A22C
025/04 () |
Field of
Search: |
;452/157,149,156,158,134,171 ;83/360,368,858,915.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Little; Willis
Attorney, Agent or Firm: Fletcher, Yoder & Van
Someren
Parent Case Text
RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser.
No. 888,256, filed May 22, 1992, now U.S. Pat. No. 5,205,779, which
is a continuation of U.S. application Ser. No. 754,527, filed Sep.
4, 1991, now abandoned.
Claims
We claim:
1. An apparatus for segmenting an animal carcass, said apparatus
comprising:
an imaging station having a vision system, said vision system being
arranged to scan at least a portion of said carcass, said vision
system producing a signal corresponding to only an interior image
of said scanned portion of said carcass;
a computer coupled to said vision system, said computer receiving
said signal and processing said signal to determine a cutting path
for segmenting said carcass; and
a cutting station being coupled to said computer, said cutting
station having at least one cutting implement being controllably
moveable along said cutting path to segment said carcass.
2. The apparatus, as set forth in claim 1, wherein said vision
system further comprises:
a first x-ray tube and a first image intensifier associated
therewith and a second x-ray tube and a second image intensifier
associated therewith, said first x-ray tube and first image
intensifier being positioned on one side of said carcass and said
second x-ray tube and second image intensifier being positioned on
another side of said carcass, said first and second image
intensifiers producing first and second signals corresponding to an
interior portion of said carcass.
3. The apparatus, as set forth in claim 2, wherein said vision
system further comprises:
a signal processor coupled to said image intensifiers, said signal
processor receiving said first and second signals, and said signal
processor processing said first and second signals to produce said
signal corresponding to an interior image of said scanned portion
of said carcass.
4. The apparatus, as set forth in claim 1, wherein said computer
comprises:
an expert system operating in said computer, said expert system
receiving said signal corresponding to an interior image of said
scanned portion of said carcass, and said expert system locating
pertinent bones and contours from said interior image to determine
said cutting path.
5. The apparatus, as set forth in claim 1, wherein said cutting
station comprises:
a first control coupled to said computer, said first control
receiving said cutting path and converting said cutting path into
control signals, said first control further delivering said control
signals to said cutting implement so that said control signals
controllably move said cutting implement along said cutting
path.
6. The apparatus, as set forth in claim 1, wherein said cutting
implement comprises a laser.
7. The apparatus, as set forth in claim 1, wherein said cutting
implement comprises a water jet cutting head.
8. The apparatus, as set forth in claim 1, wherein said at least a
portion of said carcass comprises a primary cut.
9. An apparatus for segmenting an animal carcass, said apparatus
comprising:
a device being adapted for transporting said carcass;
an imaging station having a vision system adapted for producing a
signal correlative to a three-dimensional image of an interior
portion of said carcass in response to said mounting vehicle
delivering said carcass to said imaging station;
a computer being coupled to said vision system, said computer
receiving said signal and being programmed to process said signal
to determine a cutting path for segmenting said carcass;
a cutting station being coupled to said computer, said cutting
station having at least one cutting implement being controllably
moveable along said cutting path to segment said carcass in
response to said mounting vehicle delivering said carcass to said
cutting station.
10. The apparatus, as set forth in claim 9, wherein said vision
system comprises:
a first x-ray tube and a first image intensifier associated
therewith and a second x-ray tube and a second image intensifier
associated therewith, said first x-ray tube and first image
intensifier being positioned on one side or said carcass and said
second x-ray tube and second image intensifier being positioned on
another side of said carcass, said first and second image
intensifiers producing said signal.
11. The apparatus, as set forth in claim 9, wherein said computer
comprises:
a signal processor coupled to said image intensifiers, said signal
processor receiving said signal, and said signal processor
processing said signal to produce a three-dimensional interior
image of said scanned portion of said carcass.
12. The apparatus, as set forth in claim 9, wherein said computer
further comprises:
an expert system operating in said computer, said expert system
receiving said three-dimensional interior image, and said expert
system locating pertinent bones and contours from said interior
image to determine said cutting path.
13. The apparatus, as set forth in claim 9, wherein said cutting
implement comprises a laser.
14. The apparatus, as set forth in claim 9, wherein said cutting
implement comprises a water jet cutting head.
15. The apparatus, as set forth in claim 9, wherein said at least a
portion of said carcass comprises a primary cut.
16. The apparatus, as set forth in claim 9, wherein said device
comprises a mounting vehicle.
17. The apparatus, as set forth in claim 9, wherein said device
comprises a conveyor belt.
18. A method of segmenting an animal carcass, said method
comprising the steps of:
irradiating at least a portion of said carcass with radiation
outside of the visible spectrum and delivering a signal
representing an interior image of said carcass in response to said
irradiation;
receiving said signal and creating a cutting path in response to
said signal; and
controllably segmenting said carcass along said cutting path.
.Iadd.
19. The apparatus, as set forth in claim 1, wherein said vision
system comprises:
at least one ultrasonic scanner adapted to contact said carcass to
produce said signal corresponding to only an interior image of said
scanned portion of said carcass..Iaddend..Iadd.20. The apparatus,
as set forth in claim 1, wherein said vision system comprising:
a CAT-scan machine for producing said signal corresponding to only
an interior image of said scanned portion of said
carcass..Iaddend..Iadd.21. The apparatus, as set forth in claim 1,
wherein said vision system comprises:
a magnetic resonance imaging machine for producing said signal
corresponding to only an interior image of said scanned portion of
said carcass..Iaddend..Iadd.22. The apparatus, as set forth in
claim 9, wherein said vision system comprises:
at least one ultrasonic scanner adapted to contact said carcass to
produce said signal corresponding to a three-dimensional image of
an interior portion of said carcass..Iaddend..Iadd.23. The
apparatus, as set forth in claim 9, wherein said vision system
comprises:
a CAT-scan machine for producing said signal corresponding to a
three-dimensional image of an interior portion of said
carcass..Iaddend..Iadd.24. The apparatus, as set forth in claim 9,
wherein said vision system comprises:
a magnetic resonance imaging machine for producing said signal
corresponding to a three-dimensional image of an interior portion
of said
carcass..Iaddend..Iadd.25. An apparatus for imaging an animal
carcass, said apparatus comprising:
a vision system being arranged to scan at least a portion of said
carcass, said vision system producing at least one signal
corresponding to an internal image of said scanned portion of said
carcass; and
a signal processor being coupled to receive said at least one
signal, said signal processor processing said at least one signal
to predict the amount of meat said carcass will
yield..Iaddend..Iadd.26. The apparatus, as set forth in claim 25,
wherein said vision system comprises:
x-ray means for producing said at least one signal corresponding to
said internal image of said scanned portion of said
carcass..Iaddend..Iadd.27. The apparatus, as set forth in claim 26,
wherein said x-ray means comprises:
a first x-ray tube and first image intensifier associated therewith
and a second x-ray tube and second image intensifier associated
therewith, said first x-ray tube and said first image intensifier
being positioned on one side of said carcass and said second x-ray
tube and said second image intensifier being positioned on another
side of said carcass..Iaddend..Iadd.28. The apparatus, as set forth
in claim 25, wherein said vision system comprises:
at least one ultrasonic scanner adapted to contact said carcass to
produce said at least one signal corresponding to said internal
image of said scanned portion of said carcass..Iaddend..Iadd.29.
The apparatus, as set forth in claim 25, wherein said vision system
comprises:
a CAT-scan machine for producing said at least one signal
corresponding to said internal image of said scanned portion of
said carcass..Iaddend..Iadd.30. The apparatus, as set forth in
claim 25, wherein said vision system comprises:
a magnetic resonance imaging machine for producing said at least
one signal corresponding to said internal image of said scanned
portion of said carcass..Iaddend..Iadd.31. The apparatus, as set
forth in claim 25, wherein said signal processor comprises:
an expert system for receiving said at least one signal and
processing said at least one signal to predict the amount of meat
said carcass will yield..Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to meat processing and,
more particularly, to an improved method and apparatus for cutting
animal carcasses into smaller segments.
2. Description of the Related Art
It has been estimated that the beef processing industry suffers
from over 10 billion dollars a year in efficiencies, with 3-4
billion dollars of that waste arising in the slaughter houses and
packing plants. In a conventional packing house operation, animals
are slaughtered, their hides are removed, and the resultant dressed
carcass is hung in a storage cooler for subsequent cutting. During
the cutting operation, the carcass is manually segmented by skilled
workers into primary cuts. For instance, the primary cuts of beef
are the shank, the round, the rump, the sirloin, the loin, the
flank, the rib, the chuck, the plate, the brisket, and the
shoulder. These primary cuts are then further cut and trimmed for
sale to consumers. This primary cutting operation is time consuming
and labor intensive, requiring a number of highly skilled butchers
to manually segment each carcass.
On any particular day, the manner in which the primary cuts are
made will vary depending upon the selling price that day for each
primary cut. For example, the price of a loin or shoulder cut might
vary a few cents per pound per day. When the price of a loin cut is
high, the primary cut is positioned to maximize the weight of the
loin. However, when the price of a shoulder cut is high, the
primary cut is positioned to maximize the weight of the shoulder.
Although the cuts made by the butchers are not consistently
accurate to produce the most effective yield, because carcasses
vary in size and build, and because primal cuts are not defined by
any precise symmetry, no automated butchering system exhibits more
accuracy than butchers.
Although automated butchering systems do not segment carcasses as
accurately as their human counterparts, a packing house may,
nonetheless, use automated butchering systems to prevent backlog
and to streamline their operations. Different automated butchering
systems require varying amounts of human interaction. For instance,
several automated butchering systems have been developed wherein
knives and other cutting implements, mechanically controlled by an
operator, segment a carcass as it moves along a conveyor belt.
Although cutting systems of this type have, to some extent,
decreased the total man-hours required by skilled butchers, the
greater accuracy achieved by the manual cut has been sacrificed.
For example, an operator manually controlling an automated cutting
blade is, by necessity, positioned at some distance from the
carcass to be cut as the carcass moves between various cutting
stations. Since a difference or only 1.25 inches in the position of
a cut may have an appreciable effect upon the total value realized
from the various primary cuts, the packing houses have been faced
with balancing the profit lost due to inaccurate cuts against the
profit gained due to greater operator efficiency.
In an effort to reduce operator intervention and to provide greater
cutting accuracy, external vision systems, such as television
cameras and photo sensors, have been employed to optically scan
moving carcasses and to store in memory specific physical
characteristics derived from the optical scanning procedure. The
information stored in memory is used to control automated cutting
tools which make the primary cuts. For instance, in one automated
carcass cutting system, a carcass is hung on an overhead conveyor
and the primary cuts are marked by a skilled cut specialist. The
marks for the various cuts designate both the cut direction and the
angle of cut, and the markings are made in colors which radiate
particular frequencies when scanned with a light-sensitive scanner.
When a detector senses that the carcass is in the proper position,
it triggers a video scanning camera to rapidly scan the complete
carcass. The scanning camera is filtered by a red filter so that
the red meat, white fat, and bone appear the same color. However,
the markings on the carcass radiate different frequencies and,
therefore, are sensed by the camera. The data retrieved from the
video camera is stored in a memory and used to control motor driven
knifes when the carcass moves from the scanning station to the
cutting station.
While this system relieves butchers from the burden of manually
cutting carcasses, it still requires skilled cutting specialists to
mark each of the carcasses using a proper color code. Thus, the
accuracy of the cut is limited by the accuracy of the color-coded
markings on the surface of the carcass and by the limited
maneuverability of motor driven knives. Moreover, motor driven
knives require frequent replacement, especially when required to
cut through bone as well as chilled or frozen fresh.
The present invention is directed to overcoming, or at least
minimizing, one or more of the problems set forth above.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, there is
provided an apparatus for segmenting an animal carcass. The
apparatus includes an imaging station having a vision system
therein. The vision system is arranged to scan at least a portion
of the carcass and produces signals corresponding to only an
interior image of the scanned portion of the carcass. A computer,
coupled to the vision system, receives the signals and processes
the signals to determine a cutting path for segmenting the carcass.
A cutting station, coupled to the computer, has at least one
cutting implement which is controllably moveable along the cutting
path to segment the carcass.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other advantages of the invention will become
apparent upon reading the following detailed description and upon
reference to the drawings in which:
FIG. 1A is a perspective view of an apparatus for segmenting animal
carcasses in accordance with the present invention;
FIG. 1B is a top view of another embodiment of the apparatus
illustrated in FIG. 1A;
FIG. 2A is a perspective view of a mounting vehicle for holding and
transporting an animal carcass in the apparatus illustrated in
FIGS. 1A and 1B;
FIG. 2B is a cross-sectional view of a retractable hook that forms
a portion of the mounting vehicle illustrated in FIG. 2A;
FIG. 3A is a perspective view of another embodiment of a mounting
vehicle for holding and transporting an animal carcass in the
apparatus illustrated in FIGS. 1A and 1B;
FIG. 3B is a cross-sectional view of a drive mechanism that forms a
portion of the mounting vehicle illustrated in FIG. 3A;
FIG. 4A illustrates a multi-axis control arm and water/abrasive jet
assembly for use in the cutting station of the apparatus
illustrated in FIG. 1A;
FIG. 4B illustrates a single water or abrasive jet;
FIG. 5 illustrates an exploded view of a motorized joint of the
multi-axis control arm illustrated in FIG. 4A;
FIG. 6 illustrates an exploded view of another motorized joint of
the multi-axis control arm illustrated in FIG. 4A;
FIG. 7 is a cross-sectional view of an internal port in a portion
of an arm and joint illustrated in FIG. 4A;
FIG. 8 illustrates a cross-sectional view taken along line 8--8 in
FIG. 7; and
FIG. 9 illustrates a two-dimensional view showing interior and
exterior portions of the carcass;
FIG. 10 illustrates a three-dimensional view showing interior and
exterior portions of the carcass;
FIG. 10A illustrates a three-dimensional cutting path;
FIG. 11 is a bottom view of a cutting head having nozzles for water
jets, abrasive jets, and air jets;
FIG. 12 is an end view of the cutting head of FIG. 11; and
FIG. 13 is a side view of the cutting head of FIG. 11.
While the invention is adaptable to various modifications and
alternative forms, specific embodiments have been shown by way of
example in the drawings and will be described in detail herein.
However, it should be understood that the invention is not intended
to be limited to the particular forms disclosed. Rather, the
invention is to cover all modifications, equivalents and
alternatives falling within the spirit and scope of the invention
as defined by the appended claims.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to the drawings and referring initially to FIG. 1A, an
apparatus for automatically segmenting animal carcasses is
illustrated and generally designated by a reference numeral 10.
Although the following description of the operation of the
apparatus 10 will assume that the apparatus 10 is segmenting a
cattle carcass 11, the apparatus 10 is also useful for processing
other types of animals, such as pigs and lambs. Once an animal has
been killed, the animal is preferably hung on an overhead rail
conveyor, and its hide and entrails are removed. After the animal
has been stripped and eviscerated, the carcass is typically chilled
or frozen to minimize fluid loss during subsequent processing.
After chilling, the rail conveyor 12 delivers the carcass 11 of the
animal to a mounting station 14.
At the mounting station 14, a laborer removes the animal carcass
from the overhead conveyor 12 and places the animal carcass on a
mounting vehicle 16. The mounting vehicle 16, which forms a portion
of a carcass transport system, securely holds the carcass 11 and
transports the carcass 11 from one station to another in the
apparatus 10. The mounting vehicle 16 and the carcass transport
system are described in greater detail with reference to FIGS. 3A,
3B, 4A and 4B.
After the carcass 11 is loaded onto the mounting vehicle 16, the
mounting vehicle 16 transports the carcass 11 to an imaging station
20. In the imaging station 20, a first scanner scans exterior
portions of the carcass 11, and a second scanner scans interior
portions of the carcass 11. Preferably, the first scanner includes
two television cameras 22 and 24, and the second scanner includes
two X-ray tubes 26 and 28 with their respective image intensifiers
30 and 32. A computer 34 uses the information obtained from this
scanning to create cutting paths for segmenting the carcass 11. As
will be discussed subsequently, an expert system running on the
computer 34 preferably determines the optimum cutting paths based
not only on the information obtained from the scanning, but also
based on information stored in the expert system's database.
After the scanning, the mounting vehicle 16 transports the carcass
11 to a cutting station 40 where cutting implements 42 cut the
carcass 11 along the created cutting paths. Preferably, the cutting
paths are computed so that the cutting implements 42 cut the
carcass 11 into primary cuts, such as the shank, the round, the
rump, the sirloin, the loin, the flank, the rib, the chuck, the
plate, the brisket, and the shoulder. These primary cuts fall onto
a conveyor belt 44 that operates below the carcass 11. The conveyor
belt 44 delivers the primary cuts for further butchering or
transport to a wholesale outlet.
The additional butchering may be accomplished by butchers or by
using another image station and cutting station. The additional
image station and cutting station are similar to those illustrated,
except the primary cuts travel on a conveyor belt rather than on
the mounting vehicle 16. However, in some situations, it may be
possible to simplify the additional image station, the additional
cutting station, or both. For instance, if the initial imaging
station does not reveal any abnormalities in the carcass, the
additional imaging station may include only a simple external
scanner, such as a single television camera, that determines how
each primary cut is oriented on the conveyor belt. The cutting
station would cut each primary cut into smaller pieces based on
this orientation information and, possibly, stored information
regarding each type of primary cut. Similarly, a cutting station
having four implements arranged as illustrated may not be the best
way to further segment the primary cuts. The number and arrangement
of cutting elements should be chosen to maximize the efficiency of
segmenting the primary cuts on the conveyor belt. For instance, in
some situations, a single, linearly moveable cutting implement may
suffice, while, in other situations, two or more cutting implements
may be attached to multi-axis arms arranged above the conveyor
belt.
From the cutting station 40, the mounting vehicle 16 proceeds to a
cleaning station 50. At the cleaning station, workers remove any
fluids or portions of the carcass 11 that remain on the mounting
vehicle 16. Alternatively, the high pressure water jets (not
shown), which are positioned in relation to the mounting vehicle
16, may be used to clean the mounting vehicle 16. Once cleaned, the
mounting vehicle 16 returns to the mounting station 14 to receive
another carcass 11.
Although the apparatus 10 relieves butchers from the arduous task
of segmenting animal carcasses into large primary cuts, the main
benefit of the apparatus 10 lies in its efficient approach to
segmenting animal carcasses 11. Therefore, the number of stations
14, 20, 40 and 50 and of mounting vehicles 16 are advantageously
selected to maximize efficiency. For instance, assume that the
apparatus 10 illustrated in FIG. 1A can segment a carcass in the
same time that it takes to scan another carcass. This assumption is
fairly accurate since a complex cutting station 40 including four
cutting implements 42, as illustrated, can segment a carcass in
about one or two minutes. Thus, the apparatus should contain at
least four mounting vehicles 16, one imaging station 20 and one
cutting station 40. With four mounting vehicles 16, respective
carcasses can be loaded, scanned, and cut simultaneously.
However, if the cutting station 40 takes twice as long to segment a
carcass as the imaging station 20 takes to scan a carcass, then the
cutting station 40 decreases the efficiency of the entire
apparatus. To solve this problem, as shown in FIG. 1B, a second
cutting station 40B is positioned in parallel with the first
cutting station 40A to receive every other carcass 11 that leaves
the imaging station 20. Similarly, if the imaging station 20 takes
twice as long to scan a carcass 11 as the cutting station 40 takes
to segment a carcass, then an additional imaging station 20B is
incorporated into the apparatus 10 in parallel with the first
imaging station 20A. The single cutting station 40A then receives
each carcass 11 from the two imaging stations 20A and 20B. In each
of these situations, at least five mounting vehicles are used so
that each station is fully utilized.
In addition to customizing each apparatus 10 so that it works
efficiently, to optimize the overall butchering process, from
killing the animal to shipping packaged retail cuts, several
apparatuses 10 may be required or a single apparatus 10 may require
further customizing. For instance, if the laborers can prepare 100
carcasses per hour to be segmented by an apparatus 10, and the
apparatus 10 can only segment twenty carcasses per hour, then using
five different apparatuses 10 would optimize overall
efficiency.
Referring now to the remaining drawings, the components of the
apparatus 10 will be described in greater detail. FIGS. 2A, 2B, 3A
and 3B illustrate two embodiments of the mounting vehicle 16 in
greater detail. As illustrated FIGS. 2A and 3A, the mounting
vehicle 16 includes an upper saddle portion 52 and a lower base
portion 54. The saddle portion 52 is shaped somewhat like a pommel
horse in that it is rectangular or oblong in shape. In the mounting
station 14, the cavity of the eviscerated carcass 11 is placed over
the saddle portion 52, so that the mounting vehicle 16 transports
the carcass 11 in a fairly natural position with its spine roughly
parallel to the ground and its legs hanging downwardly.
To hold the carcass 11 in place during transport and during
subsequent cutting operations, a plurality of retractable hooks 56
reside within the saddle portion 52. After the carcass has been
placed on the saddle portion 52, the hooks 56 are actuated from
their retracted position to an extended position so that the hooks
56 grip or pierce into the cavity walls of the carcass 11.
Alternatively, the hooks 56 may be angled upwardly so that, when
extended, the hooks on one side of the mounting vehicle 16 converge
toward the hooks on the other side of the mounting vehicle 16. In
this configuration, the hooks 56 grip or surround the spine of the
carcass 11 to hold it on the mounting vehicle. The outer ends of
the hooks 56 may be flat, rounded, or pointed, depending on which
configuration best holds the carcass to be segmented.
A variety of mechanisms may be used to actuate the retractable
hooks 56. As illustrated in FIG. 2B, the hooks 56 are preferably
hydraulically or pneumatically actuated. Fluid enters and exits the
cylinder 58 through a coupling 60 to respectively extend and
retract the piston 62 which serves as the hook 56. Preferably, the
mounting vehicle 16 carries a hydraulic or pneumatic source 64 for
supplying fluid to the hooks 56.
Alternatively, adjacent hooks 56 can be connected to respective
racks which are moved back and forth by the rotation of a pinion
gear (not shown). The pinion gear can be rotated manually,
mechanically, or electrically. As another example, each retractable
hook 56 can be a piston of a solenoid. The piston is spring-biased
toward its extended position so that application of an electric
current to the stationary winding of the solenoid retracts the
piston.
Whatever form the hooks 56 take, they can be activated in any of a
variety of ways. Preferably, the hooks 56 are activated and
deactivated manually as the operator chooses. A lever 66 associated
with the circuit controlling the hooks 56 is provided at the rear
of the mounting vehicle 16. Moving the lever 66 in a first
direction retracts the hooks 56 and moving the lever 66 in a second
direction extends the hooks 56. Alternatively, by using a pressure
sensitive switch (not shown), the hooks 56 may be activated by the
pressure of the carcass 11 when placed on the saddle portion 52,
and deactivated when the pressure of the carcass 11 is removed
during the cutting operation. As another alternative, the hooks 56
may be automatically activated in response to the mounting vehicle
16 reaching a particular point in the apparatus 10 before entering
the image station 20, and automatically deactivated when reaching
another point in the apparatus 10 after exiting the cutting station
40.
The mounting vehicle 16 represents a significant advance over
overhead rail conveyors that hold a carcass during cutting
operations. The overhead rail conveyors tend to allow the carcass
to move or swing in response to the force of the cutting implement.
In contrast, the mounting vehicle 16 rigidly secures the main
portion of the carcass during the cutting operations, so that the
force of the cutting implements will not move the carcass by any
appreciable amount. Thus, cutting implements segment the carcass
more accurately when the carcass is held on the mounting vehicle
16.
The mounting vehicle 16 can transport a carcass 11 between the
various stations in any one of a variety of ways. Preferably, each
mounting vehicle 16 is self-propelled. As illustrated in FIG. 2A,
the base portion 54 of the mounting vehicle 16 houses a motor 70.
The motor 70 drives a rear axle 72 via a chain or belt 74. The
motor 70 also supplies power to the fluid supply 64 if required,
e.g., if the fluid supply 64 is a hydraulic pump. Preferably, the
mounting vehicle 16 follows a preselected path 76. For instance,
the path 76 may be a wire imbedded into the floor of the
slaughterhouse, the path 76 may be a slot in the floor of the
slaughterhouse, or, for a more complex self-propelled system, the
path 76 may be a programmed path. Regardless of which type of
self-propelled system is selected, the base portion 54 most likely
carries motor and/or guidance control circuitry 78. The circuitry
78 automatically controls the motor 70 in response to signals
delivered to the circuitry from sensors (not shown) in the path 76
or from a central computer control, such as the computer 34. In
addition, the base portion 54 preferably covers the drive and
control components of the mounting vehicle 16 to protect them from
the working environment in the apparatus 10.
The advantages of using self-propelled mounting vehicles 16 are
numerous. First, self-propelled vehicles, particularly those
utilizing self-guided or wire-guided systems, permit a flexible
layout or the stations of the apparatus 10. Second, the layout of
the stations can be changed or additional station can be added
easily. Third, each vehicle 16 may be independently controlled to
further enhance the efficiency of the apparatus 10.
Even though self-propelled mounting vehicles offer many advantages,
they are typically rather expensive. Therefore, other types of
propulsion systems may be used to move the mounting vehicles 16
between the various stations. One such system is illustrated in
FIGS. 3A and 3B. The base portion 54 of the mounting vehicle 16
rides atop a rail system 80 so that the mounting vehicle 16 may be
transported to the various work stations of the apparatus 10. As
illustrated by the cross-sectional view of FIG. 3B, the base
portion 54 includes two downwardly-extending legs 82 and 84 which
envelope opposing rails 86 and 88 of the rail system 80. A bottom
surface 90 of the base portion 54 rides atop the opposed rails 86
and 88, while the legs 82 and 84 tend to stabilize the mounting
vehicle 16 as it travels along the rails 86 and 88.
In order for the mounting vehicle 16 to move, it is connected to a
drive mechanism 92. As illustrated, the drive mechanism 92 is a
chain that moves longitudinally between the rails 86 and 88. A
extendable and retractable peg 94 is disposed in a slot 96 formed
in the bottom surface 90. The peg 94 may be, for example, the
piston 95 of a solenoid, a hydraulic cylinder, or a pneumatic
cylinder 97. When extended, the peg 94 slides through an aperture
in an upwardly extending flange 98 that is attached to the drive
mechanism 92. Once coupled to the drive mechanism 92, movement of
the drive mechanism 92 produces movement of the mounting vehicle
16. Preferably, either the mounting vehicle 16 or the rail system
80 includes position encoding devices (not shown) that provides
information regarding the location of the carcass 11 in relation to
the various stations of the apparatus 10.
It should be noted that the materials used to construct the
mounting vehicle 16 are advantageously selected to facilitate x-ray
imaging. The mounting vehicle 16 is preferably constructed from
plastic or composite material that permits x-ray radiation to pass
through, i.e., a material that is transparent or translucent to the
x-ray radiation, instead of from metal which blocks a large portion
of the radiation. If the mounting vehicle 16 was formed of metal or
some other material that is opaque to the x-ray radiation, then the
x-ray scanners could not produce an adequate interior image of the
carcass due to the interference from the mounting vehicle 16.
Conversely, if the mounting vehicle 16 is primarily formed of an
x-ray translucent or transparent material, then most of the
interior of the carcass 11 can be accurately imaged by the x-ray
scanners. A certain amount of metal in the mounting vehicle 16 may
not be objectionable. In fact, if metal solenoids or cylinders are
used as hooks 56, during subsequent image processing, the locations
of the hooks 56, or of other strategically-placed metal objects,
can be used as reference points during image processing.
Once the carcass 11 has been mounted on the mounting vehicle 16 in
the mounting station 14, the mounting vehicle 16 moves the carcass
11 to the imaging station 20. In the imaging station 20, internal
and external parameters of the carcass 11 are preferably
determined, and these parameters are later used to segment the
carcass 11. The external parameters may include: the dimensions of
the carcass, the position of the limbs, and contours of the
external musculature of the carcass. The interior parameters may
include: the position, density, and size of the bones; the width
and location of the fat seam; the location of certain joints;
contours of the internal musculature of the carcass; moisture
content; location of abscesses; and approximation of red meat cut
out or yield.
It should be emphasized at this point that the imaging station 20
may be used without any cutting stations. Many of the external and
interior parameters listed above can be used for inventory or other
business purposes, apart from providing valuable information for
segmenting purposes. For instance, interior data estimating the
quantity of meat, bone, and fat in a carcass can be used to
approximate the red meat cut out or yield. When the carcass is
butchered, whether by actual butchers or by an automated cutting
station, this approximation can be used for inventory or to insure
that the butchers or cutting station perform the segmenting task
adequately.
The preferred embodiment of the imaging station 20 is illustrated
in FIG. 1A. As previously mentioned, the two television cameras 22
and 24 image an exterior portion of the carcass when the carcass is
in the imaging station 40. Two-camera three-dimensional industrial
machine vision systems ae well known in the art, and any one of a
variety of these systems can be used in the imaging station 40.
Additionally, two x-ray tubes 26 and 28 having opposed image
intensifiers 30 and 32 are used to produce three-dimensional images
of an internal portion of the carcass. While not being generally
known or used in industry, dual x-ray tubes and intensifiers are
used in the medical sciences to produce three-dimensional images of
a patient's internal organs.
Since x-ray scanners are used during imaging, the imaging station
20 is preferably designed to prevent radiation from exiting the
imaging station 20. Lead preferably lines the walls 110 of the
imaging station 20, as well as an entrance door 112 and an exit
door 114. The doors 112 and 114 open to allow a mounting vehicle 16
to enter or exit, and the doors 112 and 114 close during imaging.
Preferably, each of the doors 112 and 114 includes a flexible door
member, a roller extending across the entire width of the door, and
an electric motor coupled to the roller and adapted to rotate the
roller and thereby wind the flexible door member onto or off of the
roller. The doors 112 and 114 may be open and closed at the
discretion of an operator or automatically in response to the
carcass 11 reaching the desired location within the imaging station
20.
Before imaging begins, the mounting vehicle 16 or the carcass
thereon is positioned in a known location within the imaging
station 20. For instance, a detector, such as a photodiode, is
positioned within the imaging station 20 to deliver a control
signal in response to the carcass 11 or the mounting vehicle 16
reaching a predetermined location. This control signal causes the
drive mechanism of the mounting vehicle 16 to stop the mounting
vehicle 16 in the predetermined location. As previously alluded to,
this control signal may also be used to trigger closure of the
doors 112 and 114. Alternatively, if the mounting vehicle 16 is
automatically guided by a computer, the coordinates of the
predetermined location can be programmed so that the mounting
vehicle 16 stops in the predetermined location.
Once in position, the interior and exterior portions of the carcass
are scanned. Since the signals delivered by the television cameras
22 and 24 and by the x-ray tubes 26 and 28 do not interfere with
one another, the interior and exterior of the carcass can be
scanned simultaneously. Typically, neither the television cameras
22 and 24 nor the x-ray tubes 26 and 28 will be capable of scanning
the entire carcass without some relative movement between the
carcass 11 and the respective scanners. Therefore, the carcass 11
can be moved by the mounting vehicle 16 at a controlled rate past
the scanners. In this instance, the television cameras 22 and 24
and the x-ray tubes 26 and 28 with their opposed image intensifiers
30 and 32 should be positioned to rapidly scan the complete carcass
11 as the carcass 11 moves past.
Alternatively, though not preferable due to the increased expense,
the mounting vehicle 16 can hold the carcass 11 stationary while
the television cameras 22 and 24 and the x-ray tubes 26 and 28 with
their associated image intensifiers 30 and 32 move along the length
of the carcass 11. In the medical practice, each x-ray tube and its
associated image intensifier are mounted onto a respective
positionable U-shaped member so that an operator can accurately
position each of the tubes and intensifiers about a patient. Having
moveable x-ray tubes and intensifiers is preferable in the medical
practice because moving a patient during a surgical procedure is
generally not recommended. However, the present application creates
no such concerns. Therefore, to avoid the expense and considerable
clutter associated with moving the scanners, it is preferable to
use stationary scanners and to move the carcass 11 past the
scanners.
Strategic placement of the x-ray tubes 26 and 28 and their
associated image intensifiers 30 and 32 facilitates their
production of the interior images. For instance, if the lower
portion of the mounting vehicle 16 contains a motor or other metal
parts that can interfere with the interior image, each x-ray tube
26 and 28 and its respective image intensifier 30 and 32 should be
arranged so that the motor does not intrude into the image field.
Therefore, the x-ray scanners are preferably placed in an x-shaped
configuration where each x-ray tube 26 and 28 is mounted on either
side of the carcass 11 as it passes through the mounting station
40. Depending upon the height of the mounting vehicle 16 and the
length of the legs of the carcass 11, the legs may hang on either
side of the drive mechanism of the mounting vehicle 16, and, thus,
preclude imaging the total carcass without interference. However,
since only the body of the carcass 11, not the lower portions of
the legs, is typically segmented, imaging of the entire carcass is
not necessary.
The image signals from the television and x-ray scanners are
delivered to the computer 34 for processing. Since the processing
of image signals from television and x-ray scanners is well known,
the processing performed by the computer 34 will not be described
in detail herein. Preferably, the WHIP software package available
from G. W. Hannaway and Associates of Boulder, Colo. is used to
process the image signals from the television scanners, and the
EXPERT and/or I.X.L. software packages available from Intelligence
Ware of Los Angeles, Calif. are used to process the internal image
signals from the x-ray scanners. Briefly, the images from the
television and x-ray scanners are digitized so that the computer 34
can process the digitized image signals. The computer 34 forms a
real time, three-dimensional volumetric image, as illustrated in
FIG. 10. The image has spatial and density data that completely
describes the carcass in the virtual memory of the computer 34.
Volumetric computer image software packages, such as those
available from Hannaway or from Dynamic Graphics of Alameda,
Calif., can be used to combine the external and internal image
signals to create the three-dimensional image.
To segment the carcass 11 as an experienced butcher would segment
the carcass, the computer 34 preferably utilizes an expert system.
In essence, by interpreting the stored image, the expert system
produces three-dimensional cutting paths through the carcass 11.
The cutting paths are converted into commands for the cutting
implements 42. This conversion may be accomplished by the computer
34 or by a control associated with the cutting implements 42.
Referring to FIGS. 9, 10 and 10A, to produce the cutting paths, the
x-ray scanners are preferably adjusted to produce discernable
images of certain bones in the carcass 11. Using these images, the
computer 34 determines the positions of these bones. The expert
system utilizes this information in conjunction with the exterior
images produced by the television scanners, to determine the
cutting paths for the various primal cuts.
For instance, to determine the cutting path 111 which segments the
rump 113 from the carcass 11, the expert system locates the joint
115 where the femur 117 of the carcass joins the hip 119. The
expert system also locates the position of the tailbone 121. Since
the stored image is three-dimensional and includes not only
interior images but also the exterior contours of the carcass 11,
the expert system selects locations on the surface of the carcass
11 that correspond to the rump cut. Once the expert system has
located the relevant bones and contours, it produces a
three-dimensional cutting path 111 through the carcass 11.
To facilitate better cutting path selection, the carcass 11 may be
scanned in a manner to obtain two internal images having different
resolutions. For instance, the carcass 11 can be scanned twice by
the x-ray scanners. During the first scan, the x-ray scanners are
set at a relatively high intensity to produce an image of the bones
of the carcass 11. During the second scan, the x-ray scanners are
set at a lower intensity to produce an image of the internal
musculature of the carcass 11. Alternatively, two sets of x-ray
scanners can be used at the same intensity to scan the carcass 11.
One scanner is provided with a filter, such as an aluminum filter,
so that it produces an image of the internal musculature, while the
unfiltered scanner produces an image of the bones of the carcass
11.
Using this information in conjunction with the exterior image
produced by the television scanners, the expert system can not only
locate the bones and the exterior contours of the carcass 11, but
it can also locate at least a portion of the interior contours of
the carcass 11. Thus, the cutting path 111 can be carefully
produced so that the cutting path 111 essentially follows the
internal and external musculature of the leg and rump. This image
may also define the fatty tissue of the carcass and its
relationship to the muscle tissue. If so, the cutting paths can
require the cutting implements to cut the fatty tissue from the
carcass during the cutting operation.
Alternatively, ultrasonic scanners or other probes may be used, in
combination with the internal vision system, the external vision
system, or both, to obtain information regarding the interior or
exterior of the carcass 11. For instance, an ultrasonic scanner can
be adapted to contact the carcass and deliver information regarding
the interior of the carcass, or it can be adapted to detect signals
reflected off of the carcass 11 and deliver information regarding
the exterior of the carcass. If put to this latter use, one or more
ultrasonic scanners could replace the television scanners as
external image detectors. An ultrasonic scanner is also
particularly useful to image the eye of round. This image is
processed to predict the amount of red meat in the carcass. As
another example, a moisture probe could be inserted into the
carcass 11 to approximate the density of red meat cut out from the
carcass. As yet another example, infra red imaging can also be used
to detect the location of any abscess in the carcass 11. The expert
system would evaluate this information and alter its cutting paths
accordingly to avoid cutting the abscess or to cut out the
abscess.
Although the previous discussion described the use of both an
external imaging system and an internal imaging system to provide
the three-dimensional image that is used to produce the cutting
paths, an internal imaging system may be used alone to produce a
satisfactory three-dimensional image of the carcass 11. As
previously stated, dual x-ray scanners are used in the medical
sciences to produce three-dimensional images of a patient's
internal organs. In a like manner, the dual x-ray scanners of the
imaging station 20 may be used alone to produce three-dimensional
images of the interior of the carcass 11. The software packages
mentioned previously may also be used to process the internal image
signals from the x-ray scanners into a three-dimensional volumetric
image. It should also be appreciated that a CAT-scan machine, a
magnetic resonance imaging machine, or other suitable internal
imaging device could be used in place of the x-ray scanners, or in
combination therewith, to produce a suitable three-dimensional
interior image of the carcass. While the use of the external
imaging system in combination with the internal imaging system
typically produces a more detailed three-dimensional image and,
thus, more precise cutting paths, the use of the internal imaging
system alone will produce satisfactory images and decrease the
overall expense of the apparatus 10.
After the carcass has been scanned in the imaging station 20, the
carcass 11 is transported to the cutting station 40 illustrated in
FIG. 1. A camera or detector 124 is positioned within the cutting
station 40 for determining the proper location of the carcass 11.
As the mounting vehicle 16 moves the carcass 11 into the cutting
station 40, the detector 124 determines the proper position of the
carcass 11 so that the cutting implements 42A-42D can segment the
carcass 11 along the predetermined cutting paths. Most preferably,
the detector 124 is a television camera that is positioned
similarly to the television camera 22 with respect to the carcass
11. So positioned, the image from the camera 22 can be compared to
the image from the camera 124 to determine the proper location for
the carcass 11.
As previously mentioned, the cutting station 40 includes a
plurality of multi-axis cutting implements 42. Preferably, two
cutting implements 42 are positioned on either side of the carcass
11, with one cutting implement 42 of each pair positioned near the
rear of the carcass and the other cutting implement 42 of each pair
being positioned near the front of the carcass. The two front
cutting implements 42A and 42B are mounted on a frame 116 that is
slidable along parallel rails 126 and 128 in the direction of the x
axis of the Cartesian coordinate system 120. The two rear cutting
implements 42C and 42D are similarly mounted on a frame 122 which
is also slidable along the rails 126 and 128 in the direction of
the x axis. Preferably, the frames 116 and 122 move independently
of one another so that all of the cutting implements 42A-42D can
cut along independent cutting paths simultaneously.
Referring now to FIGS. 4A, 4B, 5, 6, 7 and 8, the construction and
operation of the cutting implements 42 will be described. Since
each of the cutting implements 42 are similar to one another, FIG.
4A illustrates an exemplary cutting implement 42A. The frame 116
can move the cutting implement 42 along the rail 126 in the
direction of the double-headed arrow 130, i.e., along the x axis.
The cutting implement 42 is also mounted to a member 132 that is
adapted to move along the z axis in the direction of the
double-headed arrow 134. The cutting implement 42 includes a
cutting head 136 that is coupled to a multi-axis lever arm 138. The
multi-axis arm 138 is slidably coupled to the member 132 by a
fitting 140. The fitting 140 is adapted to move along the y axis in
the direction of the double-headed arrow 142.
The multi-axis arm 138 is preferably a robotic arm available from
ASI Robotics of Jeffersonville, Ind. However, FIG. 4A illustrates
an exemplary multi-axis arm with the understanding that a wide
variety of multi-axis arms can be used for facilitating the
segmenting of the carcass 11. The multi-axis arm 138 includes a
first arm 144, one end of which is pivotally attached to the
fitting 140 to produce angular movement in the direction of the
curved double-headed arrow 146. The other end of the first arm 144
is pivotally attached to one end of a second arm 148 to produce
angular motion in the direction of the curved double-headed arrow
150. The other end of the second arm 148 is pivotally attached to
one end of a third arm 152 to produce angular motion in the
direction of the double-headed arrow 154. The other end of the
third arm 152 is pivotally attached to the cutting head 136 to
produce angular movement in the direction of the curved
double-headed arrow 156.
It can be seen that the multi-axis arm 138 is angularly moveable
about five different axes, and its connection to the frame 116
facilitates linear movement along the x, y, and z axes of the
Cartesian coordinate system 120. In addition, as illustrated in
FIG. 4B, the cutting head 136 may also pivot about an axis 158 in
the angular direction of the curved double-headed arrow 160. If so
constructed, the arm 138 would allow angular movement of the arm
138 and cutting head 136 in six different axes. Thus, the cutting
implements 42 are more than capable of the complex movement
required to segment the carcass 11 along virtually any cutting path
determined by the expert system.
Preferably, the cutting implements 42 are driven by closed-loop DC
servo systems. As illustrated in FIG. 5, each pivotal joint 162 of
the multi-axis arm 138 is pivoted using a motor 164. Since each
joint of the arm 138 is substantially identical, the joint 162
illustrated in FIG. is exemplary. The motor 164 drives a toothed
gear 166. When the motor 164 is bolted in place on the end of the
arm 148, the toothed gear 166 extends through the aperture 170 in
the arm 148. The arm 152 has a bushing 172 at one end thereof which
is adapted to pivotally engage the apertures 170 and 174 of the arm
148. The bushing includes a toothed bore 176 that engages with the
toothed gear 166. Thus, rotation of the toothed gear 166 by the
motor 164 produces pivotal movement of the arm 152 with respect to
the arm 148. Preferably, the computer 34 delivers the cutting paths
to a control associated with cutting implements 42, and the control
converts the cutting paths into the appropriate control signals to
drive the respective motors associated with the cutting
implements.
As illustrated in FIGS. 4A and 5, the cutting head 136 preferably
includes at least two nozzles 180 and 182. The nozzle 180 directs a
high pressure water jet to cut muscle and connective tissue of the
carcass 11 along the preselected cutting path. The nozzle 182
directs a water jet carrying an abrasive medium to cut deeper
tissue and the bones of the carcass 11 along the preselected
cutting path. Preferably, each nozzle 180 and 182 directs its
respective jet at about 50,000 psi to segment the carcass 11. Hoses
183 and 185 are used to deliver cutting fluid to the respective
nozzles 180 and 182.
Although not currently preferred, lasers may be used as the cutting
head 136 to segment the carcass 11. Preferably, a "cold" laser,
such as a ND:YAG (neodimean yitrium aluminum garnet) laser, is used
to cut the meat to prevent or minimize searing. This type of laser
can be piped through a flexible pipe, such as the pipe 183, for
ease of manipulation on the multi-axis arm. If the cold laser is
capable of cutting through bone, it is preferably the only laser
used. However, if the cold laser has trouble cutting through bone,
a hot laser, such as a CO.sub.2 laser, may be used in combination
with the cold laser. Thus, as illustrated in FIGS. 4A and 5, the
laser cutting head 136 would include a cold laser 180 and a hot
laser 182. Eximer lasers in the 100 watt to 200 watt power range
may also be used, but their current cost is prohibitive for most
applications.
While a cutting head as simple as the one illustrated in FIGS. 4A
and 5 will suffice, FIGS. 11, 12, and 13 illustrate a preferred
cutting head 187 for use in segmenting the carcass 11. The
following description of the operation of the cutting head 187 will
be facilitated by understanding that the cutting head 187 is moving
generally in the direction of arrow 189 when segmenting the carcass
11. A first nozzle 191 directs a water jet to cut the first few
inches of muscle and connective tissue of the carcass 11 along the
preselected cutting path 111.
A pair of second nozzles 193 and 195 are positioned just behind the
first nozzle 191 for directing air jets against the carcass 11. The
air jets keep the flesh of the carcass 11 separated after the cut
is made by the water jet. The second nozzles 193 and 195 are
preferably angled away from one another and emit air jets about
50-70 psi to keep the flesh separated.
A sensor, such as a photodiode 197, is advantageously positioned
between the second nozzles 193 and 195. The electrical signal
emitted by the photodiode 197 changes state in response to the
photodiode 197 detecting a predetermined change in luminosity.
Specifically, if the water jet has cut the carcass 11 down to a
bone, the photodiode 197 will detect a high degree of luminosity
and deliver a corresponding electrical signal to the computer. This
signal, coupled with cutting path information that indicates that a
bone is indeed in the cutting path, activates an abrasive jet to
cut through the bone. A third nozzle 199, positioned behind the
photodiode 197, directs the abrasive jet to cut through the bone of
the carcass 11 along the predetermined cutting path 111.
While a variety of abrasive could be used in the abrasive jet,
preferably crushed eggshells or frozen CO.sub.2 pellets are used as
the abrasive. These materials will not contaminate the meat as
other abrasives, like sand, might. Moreover, the abrasive jet is
only used to cut tougher tissue or bone. The cutting path includes
information regarding the location of the bones. Thus, when the
water jet cuts down to a bone, the abrasive jet is activated to cut
through the bone.
Two fourth nozzles 201 and 203 are positioned just behind the third
nozzle 199 for directing air jets against the carcass 11. The air
jets keep the flesh of the carcass 11 separated after the cut is
made by the abrasive jet. Like the second nozzles 193 and 195, the
fourth nozzles 201 and 203 are preferably angled away from one
another and emit air jets at about 100-120 psi to keep the flesh
separated. A higher air pressure is typically required from the
fourth nozzles 201 and 203 than from the second nozzles 193 and 195
since the deeper cut produces more flesh to keep separated.
A sensor 205 is positioned just behind the fourth nozzles 201 and
203. The sensor 205 views the cutting path 111 to determined if
more cutting is necessary. The sensor 205 may be another photodiode
or a small ultrasonic transceiver. If the sensor 205 delivers an
electrical signal indicating that more cutting is necessary, the
computer determines whether the first two cuts should have
completed the cutting along the cutting path 111. If not, then a
fifth nozzle 207 is activated. The fifth nozzle 207 directs a
second water jet to cut through the remaining flesh of the carcass
11 along the predetermined cutting path 111.
Since the cutting head 187 preferably uses water jets and an
abrasive jet, water and abrasive must be delivered to the cutting
head 187 in some manner. In addition, air must be delivered to the
cutting head 187. Preferably, hoses 209, 211, and 213 are used to
carry water and abrasive to each of the respective nozzles 191,
199, and 207. Hoses 215 and 217 deliver air to the second nozzles
193 and 195 and to the fourth nozzles 201 and 203, respectively.
The hoses 209, 211, 213, 215, and 217 are advantageously formed
from coiled aluminum tubing which provides flexibility during
movement of the cutting head 187. The ends of the hoses 209, 211,
213, 215, and 217 are preferably coupled to the fluid source and
the cutting head using a metal-to-metal contact that effectively
produces a cold weld. Thus, the hoses do not contain any O-rings
that could be deteriorated by the high pressure fluid or abrasive,
yet the hoses can be easily replaced.
Alternatively, internal fluid passageways may be provided as
illustrated in FIGS. 6, 7 and 8. FIG. 6 illustrates a detailed
exploded view of the joint 162, and FIGS. 7 and 8 illustrate
detailed cross-sections of the assembled joint 162. Since each
joint of the arm 138 is similar, only one joint is illustrated and
described.
The joint 162 includes an outer sleeve 190 that is coupled to the
arm 148. Two fluid passageways 192 and 194 extend from the joint
(not shown) at the other end of the arm 148 to the sleeve 190. A
substantially solid, complimentary inner sleeve 196 is coupled to
the end of the arm 152 that attaches to the arm 148. Preferably, a
pair of set screws 214 and 216 are screwed into respective slots
218 and 220 which are formed in the inner sleeve 196 when the joint
162 is assembled.
The inner sleeve 196 has two bores 198 and 200 therethrough that
fluidically communicate with the fluid passageways 192 and 194,
respectively. Two fluid passageways 202 and 204 are coupled to the
bores 198 and 200, respectively, to carry the respective fluids to
the other end of the arm 152. The opening 206 in the outer sleeve
190 limits the pivotal movement of the arm 152 because the fluid
passageways 202 and 204 would contact the edge of the outer sleeve
190.
To ensure that the fluid passageways 192 and 194 remain in fluidic
contact with the fluid passageways 202 and 204, respectively, as
the arms 148 and 152 are pivoted relative to one another, a pair of
elongated slots 206 and 208 are formed in the inner sleeve 196. Set
screw and slot arrangement allows pivotal motion of the arm 148
relative to the arm 152, but does not permit axial movement between
the joints which would tend to misalign the fluid passageways 192
and 194 from their respective slots 206 and 208. The slots 206 and
208 are positioned to receive fluid from the fluid passageways 192
and 194 as the arm 152 is pivoted relative to the arm 148. A
respective O-ring 210 and 212 encompasses each slot 206 and 208 to
prevent fluid from the passageways from leaking out through the
joint.
* * * * *