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 extension 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 high 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.

Description

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. embodiment apparatus embodiments 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 bony 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 bony 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 bony 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 bony 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 bony material in such chamber portion 24a that tends to compensate for variations in percentage of boney bony 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 with 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 proportion of the relatively soft fleshy components from the harder boney bony 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 three-eighths 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 bony 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.

Claims

1. A de-boning machine for meat or fish materials from which boney 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.

2. A de-boning machine according to claim 1, wherein the valve means comprises ring is 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 1, 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 1, 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 bony 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.

15. A de-boning machine according to claim 1, in which said ring has an interior taper confronting said screw flights and said valleys.

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.