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.

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.