U.S. patent number RE31,631 [Application Number 06/277,675] was granted by the patent office on 1984-07-17 for apparatus for producing de-boned meat products.
This patent grant is currently assigned to Beehive Machinery, Inc.. Invention is credited to Archie R. McFarland.
United States Patent |
RE31,631 |
McFarland |
July 17, 1984 |
Apparatus for producing de-boned meat products
Abstract
Material obtained from animals, poultry, or fish and containing
edible flesh along with normally inedible relatively hard or tough
components, such as bone, gristle, tendons, etc., is fed in ground
condition into one end of a perforated conduit that has a conveyor
srew therein which progressively decreases in conveying capacity
from the feed end of the conduit to an imperforate discharge end
thereof. Such inedible components are compacted within the
imperforate discharge end of the conduit by an extension of the
conveyor screw prior to discharge following build-up and conveyance
along the interior surface of the perforate portion of the conduit
as a filter mat through which edible flesh is forced toward and
through the perforations of the conduit to provide a substantially
bone-free edible product. The discharge passage surrounding the
.[.exeension.]. .Iadd.extension .Iaddend.of the conveyor screw can
be varied in size, preferably by a tapered ring that is movable
back and forth axially of the conveyor screw extension, and
preferably the spacing between conveyor screw and conduit is
variable. The forward faces of the conveyor screw flights are
preferably concave to provide a forwardly projecting
circumferential overhang that tends to keep particles of bone near
the axis of the screw, and the conduit wall thickness is unusually
thick so as to withstand high pressures. Unusually high production
rates can be obtained by feeding finely ground material into the
conduit by means of a .[.hgh.]. .Iadd.high .Iaddend.pressure pump.
The discharged and normally inedible components can be slurried in
a digestant liquid and the digested material recovered as a food
product by the application of centrifugal force. In instances where
some minute particles of bone are discharged with the fleshy
components, they can be homogenized by subjecting such flesh
components to an attrition operation. .Iadd.
Inventors: |
McFarland; Archie R. (Salt Lake
County, UT) |
Assignee: |
Beehive Machinery, Inc. (Salt
Lake City, UT)
|
Family
ID: |
26958643 |
Appl.
No.: |
06/277,675 |
Filed: |
June 29, 1981 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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129394 |
Mar 11, 1980 |
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593532 |
Nov 10, 1966 |
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Reissue of: |
881686 |
Dec 3, 1969 |
03739994 |
Jun 19, 1973 |
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Current U.S.
Class: |
241/74; 100/117;
100/148; 241/82.3; 99/513 |
Current CPC
Class: |
A22C
17/04 (20130101) |
Current International
Class: |
A22C
17/04 (20060101); A22C 17/00 (20060101); B02B
007/04 () |
Field of
Search: |
;17/46,1G
;241/24,74,82.1,82.3,260.1 ;100/117,145,148 ;99/508,513 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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185053 |
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Jul 1955 |
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AU |
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592399 |
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Feb 1934 |
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DE2 |
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857671 |
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Dec 1952 |
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DE |
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99455 |
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Sep 1932 |
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JP |
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Other References
Meat Industry, USSR 1961, No. 2, pp. 8-9..
|
Primary Examiner: Abercrombie; Willie G.
Attorney, Agent or Firm: Burmeister, York, Palmatier, Hamby
& Jones
Parent Case Text
This application is a continuation reissue application of Ser. No.
Re. 6,129,394, filed Mar. 11, 1980, now abandoned, which was a
reissue application of U.S. Pat. No. 3,739,994, Ser. No. 881,686,
filed Dec. 3, 1969, which was a continuation-in-part of application
Ser. No. 593,532; filed Nov. 10, 1966, abandoned. .Iaddend.
RELATED APPLICATIONS
The present application is a continuation-in-part of my similarly
entitled allowed application, Ser. No. 593,532 filed Nov. 10, 1966,
which is being abandoned in favor of this application that embodies
recent improvements. The process disclosed herein in conjunction
with the apparatus is being claimed in a copending divisional
application.
Claims
I claim:
1. A de-boning machine for meat or fish materials from which
.[.boney.]. .Iadd.bony .Iaddend.components have not been removed,
comprising a perforated conduit having a feed end, a discharge end,
and a perforate intermediate portion; a compression type of
conveyor screw rotatably mounted in said conduit and progressively
decreasing in conveying capacity from feed end to discharge end
thereof, a tapered extension of said conveyor screw extending
beyond the perforate intermediate portion of said conduit; means
for rotating said conveyor screw and screw extension; means for
feeding a ground mixture of the specified meat or fish material
into the feed end of said conduit; and annular valve means
surrounding said screw extension for controlling the pressure
applied by the compression screw to said material within the
perforate intermediate portion of said conduit.Iadd.; said annular
valve means including an axially movable ring that defines, with
said screw extension, a portion of a size-adjustable, elongate,
annular discharge passage; said screw extension having a smooth
tapered outer face and channels extending longitudinally therein to
form screw flights and valleys therebetween.Iaddend..
2. A de-boning machine according to claim 1, wherein the .[.valve
means comprises.]. .Iadd.ring is .Iaddend.a tapered, imperforate
ring telescoped into the discharge end of the conduit to surround
the extension of the conveyor screw, said ring being movable back
and forth along said screw extension for varying the size of the
discharge opening at said discharge end of the conduit.
3. A de-boning machine according to claim 2, wherein the tapered,
imperforate ring is threaded into the discharge end of the conduit,
and wherein ratchet means are provided for turning said ring into
and out of said conduit. .[.4. A de-bonding machine according to
claim 1, wherein the screw extension has a smooth outer face and
channels extending longitudinally to form screw flights and valleys
therebetween..]. .[.5. A de-boning machine according to claim 4,
wherein the annular valve means includes an axially movable ring
that defines, with the screw extension, a
portion of a size-adjustable, elongate, annular discharge
passage..]. 6. A de-boning machine according to claim .[.4.].
.Iadd.1.Iaddend., wherein the discharge passage has an initial
chamber portion that feeds into the portion defined by the
discharge ring by way of an abrupt annular
shoulder. 7. A de-boning machine according to claim .[.4.].
.Iadd.1.Iaddend., wherein the screw extension has a journal
extension thereof; and wherein there are additionally provided
bearing means and axially adjustable support means for said bearing
means that enable adjustment of spacing between the flights of the
conveyor screw and the
inner surface of the conduit into which it is fitted. 8. A
de-boning machine according to claim 1, wherein the conveyor screw
and the perforated conduit are correspondingly tapered, and
adjustable means are provided for moving said screw axially to
enable it and said conduit to be
selectively spaced apart. 9. A de-boning machine according to claim
8, wherein the adjustable means comprises a stub shaft extension of
the discharge end of the conveyor screw; stationary means
journaling said shaft extension; and means carried by and
adjustable in position axially
of said shaft extension adapted to abut said stationary means. 10.
A de-boning machine according to claim 1, wherein the annular valve
means adjustable to vary the size of the discharge opening
therethrough; and wherein correlated, graduated scales are
respectively provided circularly of and along the axis of the
annular valve means for controlling valve
adjustment. 11. A de-boning machine according to claim 1, wherein
at least one elongate knife having a blade with back and cutting
edge is inset freely into the periphery of the compression screw,
extending axially and having its cutting edge disposed in shearing
relationship with
perforations thereof. 12. A de-boning machine according to claim
11, wherein the periphery of the compression screw is provided with
notches for receiving the knife, each of said notches having a back
against which the back of the knife abuts and an upwardly sloping
bottom against which
the blade of the knife rests freely. 13. A de-boning machine
according to claim 1, wherein the rearward faces of the flights of
the conveyor screw are concave to provide undercut, rearwardly
facing, outer peripheral members for the respective flights which
tend to direct fragments of .[.boney.]. .Iadd.bony
.Iaddend.material toward the axis of the screw.
A de-boning machine according to claim 1, wherein the means for
feeding a ground mixture of the meat or fish material into the feed
end of the conduit includes a pump. .Iadd. 15. A de-boning machine
according to claim 1, in which said ring has an interior taper
confronting said screw flights and said valleys. .Iaddend..Iadd.
16. A de-boning machine for meat or fish materials from which bony
components have not been removed, comprising a perforated conduit
having a feed end, a discharge end, and a perforate intermediate
portion; a compression type of conveyor screw rotatably mounted in
said conduit and progressively decreasing in conveying capacity
from feed end to discharge end thereof, a tapered extension of said
conveyor screw extending beyond the perforate intermediate portion
of said conduit; means for rotating said conveyor screw and screw
extension; means for feeding a ground mixture of the specified meat
or fish material into the feed end of said conduit; and annular
valve means surrounding said screw extension for controlling the
pressure applied by the compression screw to said material within
the perforate intermediate portion of said conduit; said annular
valve means including an axially movable ring that defines, with
said screw extension, a portion of a size-adjustable, elongate,
annular discharge passage; said screw extension having a smooth
tapered outer face and channels extending longitudinally therein to
form screw flights and valleys therebetween; said discharge passage
having a narrowest portion, said screw flights and said valleys
extending along said narrowest portion for conveying material to,
through and from said narrowest portion. .Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field
This invention relates to de-boning procedures and equipment that
involve preliminary grinding of meat materials from which normally
inedible .[.boney.]. .Iadd.bony .Iaddend.materials, herein defined
as bones, gristle, connective tissue, and the like, have not been
removed.
2. State of the Art
There are various parts of the bodies of fowl, animals, and fish,
used for food, that contain excessive amounts of bone or other
.[.boney.]. .Iadd.bony .Iaddend.material--for example, the necks
and backs of poultry--and yet contain sufficient meat, i.e.
relatively soft, fleshy matter, to .[.consitute.]. .Iadd.constitute
.Iaddend.a potential source of food if the .[.boney.]. .Iadd.bony
.Iaddend.matter could be economically eliminated. Moreover, there
is a large commercial market for meat proteins in slurry form as
supplements for ground hamburger meat, sausage meat, etc. The
poultry industry, particularly, is in need of an effective way to
de-bone whole turkey and chicken carcasses, as well as inferior
parts thereof, such as the necks and backs, in order to receive
maximum returns from flocks raised for the domestic market. Various
ways of separating .[.boney.]. .Iadd.bony .Iaddend.components from
the fleshy meat components of ground meat materials have been tried
with indifferent success. Generally speaking, the processes
employed have not been sufficiently positive in removing particles
of bone to produce a dependable and commercially acceptable
product, even though grinding the bones with the meat has posed an
attractive way of quickly and easily handling the bone along with
the meat and has opened up an added source of food in the form of
recoverable bone marrow.
BRIEF SUMMARY OF THE INVENTION
In accordance with this invention, substantially complete
elimination of .[.boney.]. .Iadd.bony .Iaddend.components of meat
materials is possible, with a high degree of meat recovery. A
somewhat higher degree of edible protein recovery is also possible
at the sacrifice of substantially complete elimination of
.[.boney.]. .Iadd.bony .Iaddend.materials during the de-boning
stage of the overall process, but without destroying utility of a
final commercial meat product obtainable by such overall process of
the invention.
An outstanding feature of the invention is the forming of a filter
mat of the relatively hard or tough .[.boney.]. .Iadd.bony
.Iaddend.components of ground carcasses or parts thereof of
animals, poultry, and fish and the squeezing of the relatively
soft, fleshy, edible parts, e.g. flesh, fat, skin, etc., through
such mat. Beyond a .[.cetain.]. .Iadd.certain .Iaddend.point, which
varies from one material to another and from particular batch to
particular batch, the more pressure applied to the ground material
during the squeezing process, the more of the gristle and
connective tissue components, e.g. tendons and ligaments, that pass
through the mat, and, as higher pressures are reached, appreciable
amounts of bone particles may even escape. For some of the final
meat products obtainable by the overall process of this invention,
it is practical to approach such higher pressures to obtain maximum
edible protein recovery, and to further process the resulting
substantially boneless product to render harmless those relatively
few bone particles that do come through.
The best form of apparatus presently developed for performing the
de-boning phase of the overall process is an extrusion machine that
comprises a perforated conduit of sufficient strength to withstand
the pressures involved, and a coacting, compression type of
conveyor screw for applying the required pressure while
transporting the ground carcass material through the conduit.
An annular valve at the discharge end of the conduit enables the
pressure exerted on the material to be varied as may be required to
produce a given de-boned product. The conveyor screw should fit
snugly but not tightly in the conduit, so as to convey
material--including the filter mat--in a continuous spiral flow,
without forcing particles of bone and other .[.boney.]. .Iadd.bony
.Iaddend.components through the perforations, except when higher
pressures are being purposely employed to increase edible protein
yield.
In smaller versions of the apparatus, a meat grinder is built into
the extrusion machine, such grinder comprising a hopper, a feed
screw arranged as an advance extension of the compression screw, so
as to discharge material into the feed end of the perforated
conduit through a rotary-knife-and-extrusion-plate type of cutter
unit that is interposed between feed and compression screws, and
power means for operating the feed screws, the rotary knife, and
the compression screw as a unit. It has been found that other
versions can advantageously employ a pump, usually high pressure,
for feeding finely ground materials into the conduit.
In the operation of the extrusion machine, a spiral, fibrous mat of
.[.boney.]. .Iadd.bony .Iaddend.components immediately commences to
build up against the inner wall of the perforated conduit by reason
of the pressure that tends to force the material outwardly toward
such wall, and such pressure causes the soft edible constituents of
the ground carcass material to filter through the mat and out
through the perforations which it covers. The filter mat becomes
thicker and thicker along the length of the compression screw until
it is carried out the discharge end of the conduit by such
screw.
It should be noted that a snug rather than tight fit (about four
.[.one-thousandth.]. .Iadd.one-thousandths .Iaddend.of an inch
clearance) of the compression screw in the perforated conduit is
advantageous to permit a thin, fibrous coating to build up and
remain over inner wall portions of the conduit that are wiped by
the flights of such screw.
In instances where higher pressures are utilized to the extent that
analysis of the product for undigestible matter (on the basis of
human digestion) shows from about 0.5 percent to about 5.0 percent
.[.boney.]. .Iadd.bony .Iaddend.material content, the deboned
product should be treated by attrition homogenization, for example,
in a colloid mill, to break down the .[.boney.]. .Iadd.bony
.Iaddend.material and render it not only harmless but nutritious as
well. The product obtained from the de-boning stage of the overall
process is peculiarly susceptible to attrition homogenization in a
colloid mill and produces a uniquely stable emulsion that can
withstand extremes of temperature without chemical breakdown.
A further recovery of edible matter can be obtained from the
.[.boney.]. .Iadd.bony .Iaddend.waste material extruded through the
discharge valve of the machine by slurrying such .[.boney.].
.Iadd.bony .Iaddend.waste material with an aqueous solution of a
.[.protolytic.]. .Iadd.proteolytic .Iaddend.enzyme, an edible acid
solution, or some other type of protein digestant solution and by
thereafter passing the slurry through a centrifugal extractor.
Although I have found that the de-boning .[.extrusin.].
.Iadd.extrusion .Iaddend.machine of this invention has some
features in common with a certain type of juice extractor for
fruits and vegetables, such as is shown by U.S. Pat. Nos.
2,119,972, 2,345,683, and 2,513,974, there are significant
differences that adapt such features to the purposes of the present
de-boning process.
THE DRAWINGS
There are shown in the accompanying drawings specific embodiments
of machines representing what is presently regarded as the best
mode of carrying out the de-boning phase of the overall process of
the invention, along with a flow sheet representing what is
presently regarded as the best mode of carrying out such overall
process. From the detailed description of these, other more
specific objects and features of the invention will become
apparent.
In the drawings:
FIG. 1 represents a top plan view of a relatively small capacity
machine of the invention incorporating a meat grinder with the
de-boning extrusion machine;
FIG. 2, a longitudinal axial section taken on the line 2--2 of FIG.
1;
FIG. 3, a transverse vertical section taken on the line 3--3 of
FIG. 1;
FIGS. 4, 5, 6, and 7, similar sections taken on the lines 4--4,
5--5, 6--6, and 7--7, respectively, of FIG. 1;
FIG. 8, a fragmentary portion of FIG. 1 drawn to a larger scale and
showing an alternative arrangement;
FIG. 9, a transverse section taken on the line 9--9 of FIG. 8;
FIG. 10, a flow sheet showing a typical series of steps in the
overall process of the invention;
FIG. 11, a view corresponding to that of FIG. 1, but illustrating a
machine that includes a pump for feeding finely ground meat
materials to the de-boning portions of the machine and various
other structural modifications;
FIG. 12, a view corresponding to that of FIG. 2, but illustrating
the machine of FIG. 11 and showing a somewhat different
construction for the screw flights in fragmentary, longitudinal,
vertical section;
FIG. 13, a transverse vertical section taken along the lines 13--13
of FIG. 11 and FIG. 12, respectively; and
FIG. 14, the left hand portion of FIG. 11 enlarged to show
correlated scales marked on the adjustable discharge valve and
longitudinally extending, and adjacent, stationary structure,
respectively.
DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS
In the small machine illustrated in FIGS. 1-7, a meat grinder 10 of
generally conventional type is combined with the de-boning
extrusion machine of the invention. It comprises a tube 11 having a
conveying screw 12 therein for receiving from hopper 13 the carcass
material to be de-boned and feeding it, through grinding mechanism,
to the de-boning mechanism.
One end of the screw 12 is formed as a shaft 12a, and extends
through a bearing 14 to connection with suitable drive means, such
as a gear box 15 powered by an electric motor (not shown). The
other or discharge end of the screw 12 connects in mated,
separable, drive relationship with a stub shaft 16a, FIG. 4, at the
feed end of a second conveyor screw 16 of compression type. Such
stub shaft 16a extends through and is journaled by a peforated
cutter plate 17 that forms part of the grinding mechanism. Beyond
this, such stub shaft is square in cross-section, see FIG. 3, for
mating with the discharge end of screw 12. Fitted on such square
portion of the stub shaft 16a, immediately in advance of the cutter
plate 17 and bearing against the forward face thereof in shearing
relationship therewith, is a multi-bladed knife 18 that rotates
with the screws 12 and 16 and serves to cut or grind material
passing from the discharge end of feed screw 12 into the receiving
end of compression screw 16.
Compression screw 16 is preferably snugly but not tightly fitted
into the separation chamber defined by and within a perforated
conduit 19 of circular cross-section. Such conduit has a receiving
end 19a that is preferably demountably connected, as by means of a
threaded coupling 20, with the discharge end of feed tube 11, and
has an imperforate discharge end 19b that is telescopically
connected, as by the screw threads shown, with the receiving end
21a of an imperforate, open-ended, tapered, discharge ring 21 that
forms part of a discharge valve arrangement.
Conduit 19 is preferably perforated about its complete
circumference and longitudinally a distance covering several
convolutions of the screw 16. Its wall is heavy enough to withstand
the considerable pressure employed during the de-boning operation.
For a conduit made from AD150 grade stainless steel, specially
hardened by heat treatment to withstand severe abrasive forces, and
having a perforated area three inches in length (5000 uniformly
spaced holes each 40/1000 of an inch in diameter) and tapering from
an inside diameter of three and one-half inches at the feed end to
three and five sixteenths inches at the discharge end, a wall
thickness of one-quarter of an inch has been found satisfactory
under all conditions of use. Generally speaking, a wall thickness
less than one-eighth of an inch is too light, while more than
one-quarter of an inch is uneconomical for any of the .[.embodiment
apparatus.]. .Iadd.embodiments .Iaddend.of the invention.
Circumferential flanges 19c ae preferably provided at opposite
ends, respectively, of the perforated area as guides for the
extruded meat product.
Both conduit 19 and its coacting compression screw 16 are
preferably tapered from feed end to discharge end, as just
indicated, to provide for positioned adjustment of such screw in
the conduit 10 to compensate for wear and to provide variations in
spacing from conduit wall surface as may be desired. The taper may
be slight, e.g. from 5 to 10 percent, or may be great so that the
configuration is more conical that it is cylindrical. In any event,
the spiral valleys 16b between flights 16c of such screw 16 become
progressively more shallow, so the screw progressively decreases in
conveying capacity and acts with increasing force to press the
conveyed material outwardly against the perforate wall of conduit
19.
As soon as the feed material from grinder 10 enters the smaller
diameter de-boning conduit 19 in ground condition, it is pressed
outwardly under moderate pressure. Such pressure progressively
increases as the material travels along the length of screw 16. The
pressure causes fibrous .[.boney.]. .Iadd.bony .Iaddend.material to
mat, albeit thinly, at the inner wall of conduit 19 and across
perforations 22 before any significant quantity of the relatively
soft meat material can escape, and thereby immediately commences to
filter .[.boney.]. .Iadd.bony .Iaddend.material from such soft meat
material as the latter is squeezed from the valleys 16b through the
mat and thence through the perforations 22. The mat progressively
increases in thickness along the length of the screw and is carried
along by the screw to the discharge end of the separation chamber,
where it is forced into and through the previously mentioned
discharged valve arrangement 23.
Such valve arrangement comprises a tapered discharge extension 16d
of compression screw 16 that projects beyond perforated conduit 19
and extends along the passage formed by the imperforate discharge
end 19b of perforate conduit 19 and by the telescoped discharge
ring 21. Between such elements 19b and 21 and the tapered discharge
extension 16d of compression screw 16 is formed a restricted,
annular, discharge passage 24, through which the final mat of
.[.boney.]. .Iadd.bony .Iaddend.material passes in discharging from
the machine.
Discharge ring 21 has an interior taper that is slightly greater
than the taper of discharge extension 16d of screw 16, so that, as
the end 21a of the ring is screwed farther into the imperforate
discharge end 19b of conduit 19, the size of the annular discharge
passage 24 of valve 23 is decreased. This passage thus provides a
variable restriction to flow of the mat of .[.boney.]. .Iadd.bony
.Iaddend.material. The pressure in the separating chamber will be
dependent upon the size of this discharge passage 24 as determined
by the position of discharge ring 21. Thus, it is apparent that
both the edible meat components and the normally inedible boney
material components are separately extruded from the machine under
the control of ring 21 serving as an adjustable discharge valve
element.
Extension 16d, as illustrated, FIG. 2, advantageously has a smooth
outer face and channels 23a extending longitudinally to form screw
flights and valleys therebetween for the elongate, annular,
discharge passage 24 of the valve. Such passage 24, as indicated,
preferably has an initial chamber portion 24a that feeds into the
portion defined by the discharge ring 21 by way of an abrupt
annular shoulder 21b, thereby establishing an elastic ring or choke
of .[.boney.]. .Iadd.bony .Iaddend.material in such chamber portion
24a that tends to compensate for variations in percentage of
.[.boney.]. .Iadd.bony .Iaddend.components in the material being
deboned.
A reversible ratchet is advantageously employed to screw discharge
ring 21 farther into or farther out of conduit 19. For this
purpose, such ring 21 is formed as a ratchet wheel .[.which.].
.Iadd.with .Iaddend.notches 25 about its exterior periphery. An
operating ring 26 fits around discharge ring 21 and is rotatable
relative thereto by means of a handle 26a. Resiliently biased in
conventional manner within a knob member 26b of such operating ring
26 is a pawl 27. To reverse the pawl so that discharge ring 21 can
be screwed in a reverse direction, it is only necessary to turn
knob member 26b, as is customary in ratchet construction of this
type, there being no need to go into further detail in view of the
well known nature of this mechanism.
For both journaling the discharge end of compression screw 16 and
enabling its position within conduit 19 to be adjusted to
compensate for wear or to increase or decrease the spacing between
conveyor screw and conduit, a plate 28 equipped with a central
bearing 29 is rigidly supported in fixed spaced relationship with
discharge ring 21 by means of pins 30 extending longitudinally from
fixed securement in flange 19c of conduit 19. The discharge end of
extension 16d of compression screw 16 is reduced in diameter and
provided with a stub shaft extension 31, FIG. 2, having a journal
portion flanked by threaded portions on which are respective
adjusting nuts 32 and 33. These nuts are normally cinched tightly
against bearing 29 to prevent axial movement of compression screw
16, but when wear of the flights 16c has increased the desirable
tolerance between screw and conduit it is only necessary to loosen
nut 33 and tighten nut 32 to effect the adjustment. This
arrangement also permits such tolerance to be increased or
decreased as may be desired.
Often fleshy muscle material passing through perforations 22 of
conduit 19 is fibrous and exerts a strong drag on the material
being transported axially of compression screw 16 toward discharge
passage 24. In order to eliminate or significantly ease this drag
and so increase throughput capacity of the machine, it is sometimes
advantageous to position one or more knife blades across the
flights of the screw, so as to extend axially of the screw at the
outer periphery of such flights. Thus, as shown in FIGS. 8 and 9,
knives 34 and 35 are freely inset into receiving notches 36 in the
flights 16c of the compression screw 16 of this alternative
embodiment of the deboning machine with the back of each knife
abutting the back 36a of its notch, the blade resting on the
upwardly sloping bottom .[.36b.]. of the notch, and the sharp edge
bearing lightly against the inner wall of the conduit 19 in
shearing relationship with the edges of perforation 22. The
shearing angle should be small to prevent or minimize scoring of
such inner wall of conduit 19.
In operation, the knives 34 will cut the fibers that create drag,
but will not destroy the filter mat that covers the perforations
exposed to the valleys 16b between flights.
In this combination, attention is called to the double meat grinder
of Ardrey U.S. Pat. No. 2,841,197, which has a somewhat similar
construction, but is not intended nor adapted for the de-boning of
meat that is ground together with boney components.
In accordance with the process of the invention as depicted
diagrammatically in the flow sheet of FIG. 10, raw carcass material
is ground before being fed into the de-boning machine, which
separates a high .[.proportin.]. .Iadd.proportion .Iaddend.of the
relatively soft fleshy components from the harder .[.boney.].
.Iadd.bony .Iaddend.components. The former constitute a finished
meat product; the latter, in matted form, can be used for both
stock or animal feed or can be processed further, as indicated by
broken lines, by digestion of protein constituents through the
addition of a protein digestant and by passage through a centrifuge
to eliminate undigested boney components.
In instances where higher de-boning pressures are used, by setting
of the discharge valve of the de-boning machine to narrow the
discharge passage 24, so that more bone particles pass through the
filter mat than can be tolerated in a commercial meat product, the
resulting inferior meat product is passed through a colloid mill or
other apparatus for effecting homogenization by attrition to
produce a stabilized colloidal meat emulsion in which the bone
particles have been so disintegrated as to be harmless.
It has been found that enormously increased throughput, without
significant decrease in de-boning effectiveness, can be achieved by
forced feed or finely ground meat or fish materials into the
de-boning conduit under pressure, usually accomplished by means of
a pump, and that other features to be described improve the
effectiveness of the machine.
In the embodiment of FIGS. 11-14 a slurry of meat or fish material
ground in standard equipment, e.g. a high pressure extrusion type
grinder whose extrusion passages are each five-sixteenths or
.[.three-eighth.]. .Iadd.three-eighths .Iaddend.of an inch in
diameter, is run into a hopper 40 equipped with double mixing
screws 41 and 41a to keep the solids in suspension. The lower screw
41a feeds the slurry into the intake end of any suitable pump 42,
for example a rotary vane, stainless steel, pet food pump as
marketed by Autio Equipment Company, Astoria, Oregon, having its
working parts specially hardened against bone abrasiveness. A
conduit 42a conducts pump discharge into the feed end of de-boning
conduit 43, see especially FIG. 13, under pressure that may vary
between about 5 to 250 lbs/sq. in., depending upon volume and
character of feed and speed of rotation of the conveyor compression
screw.
The conveyor compression screw 44 is similar to the corresponding
screw 16 in the previous embodiments, but its stub shaft portion
44a is journaled in an imperforate entry section 45 of the
perforated de-boning conduit 43 and connects with drive means 46
housed below hopper 40; also, the rearward faces of its flights are
made concave, as at 44b, to provide respective overhanging,
rearwardly facing, peripheral members 44c that tend to force
fragments of .[.boney.]. .Iadd.bony .Iaddend.material toward the
axis of the screw. Perforated conduit 43 corresponds to conduit 19
of the previous embodiments, as do other components of the
de-boning mechanism, including the discharge ring 47 and ratchet
ring and handle 48 of the discharge valve. However, the
compression-screw- journaling plate 49, and longitudinally
extending supporting members 50, and imperforate discharge end 51
of conduit 43 are preferably made as a single casting, as shown,
rather than separately as in the previous embodiments and are
secured to the end of conduit 43 as by means of screw 52. Moreover,
the attenuate pins of the previous embodiments have been replaced
by the relatively wide members 50 to provide increased
strength.
In order to enable precise adjustment of the discharge valve
opening of conduit 43, a scale 53 is marked circumferentially
around a rearwardly extending rim 47a of a discharge ring 47 and a
correlated scale 54 is marked longitudinally along one of the
stationary supporting members 50.
The several new features noted for the embodiment of FIGS. 11-14
can be incorporated in the embodiments of FIGS. 1-13 if
desired.
Whereas this invention is here described and illustrated with
respect to certain preferred forms thereof, it is to be understood
that many variations are possible without departing from the
inventive concepts particularly pointed out in the claims.
* * * * *