METHOD OF AND MEANS FOR STRIPPING MEAT FROM BONES

Abstract: A method of stripping meat from bones including directing a high pressure fluid jet at a meat/bone interface to sever the bond therebetween and peel the severed meat from the bone. Suitably the fluid jet is a liquid jet which is directed at an oblique angle to the interface. The bone or bones may be mounted from rotation such that after application of the fluid jet the severed meat may be peeled away from the interface by centrifugal force to a position remote therefrom. The fluid jet is suitably adapted for reciprocation in a direction substantially parallel to the longitudinal axis of the bone or bones. The invention also includes apparatus for carrying out the above-mentioned method including mounting means which is suitably rotatable for mounting of a bone or bones, and a fluid jet which is suitably supported by a traversing assembly. Preferably the jet is mounted at an oblique angle with respect to a mounting shaft which can carry a traversing sleeve which is a preferred form of traversing assembly.

Description: METHOD OF AND MEANS FOR STRIPPING MEAT FROM BONES THIS INVENTION relates to a method of and means for stripping meat from bones. At present, the boning of dressed carcasses is largely a manual operation. Operators firstly remove the large cuts of meat, leaving the carcass with a significant quantity of meat thereon. This meat is removed in a secondary deboning operation in which operators with sharp manual and electric knives carefully cut the small pieces of meat away from the bones. The efficiency of this operation is largely dependent on the skill of the boners. Highly skilled operators can maintain a high meat removal rate. Less skilled operators frequently cut the bone which blunts the cutting blade and results in time being lost for frequent sharpening operations. Of course the efficiency of meat removal during deboning operations in part relates to the accessibility of the portion of abeast being treated. The neck of a carcass is a difficult portion to process so the labour content must be small for such yields to be viable. Typically, after removing as much meat from a sheep neck as is economically viable using existing manual deboning methods, a further quantity of up to 0.3 kg of meat pieces can be recovered using this secondary process. Attempts have been made in the past to recover saleable products from processed bones. For example extrusion machines are used to recover meat, fat, connective tissue and marrow from bones. The material obtained is not identifiable meat, but is pastelike and as such it has a low market value and the economy of such operations is reduced as such machines are expensive to purchase and install. Alternatively the bones may be rendered for meat/bone meal and tallow. This provides only a very small economic return. The present invention aims to alleviate the dis¬ advantages associated with the above methods of treating processed bones and to provide deboning apparatus and a method of deboning which will be reliable and efficient in use. -__ - The invention in one aspect resides broadly in a method of stripping meat from bones including directing a high pressure fluid jet to a meat-bone interface to sever the bond therebetween and peel the severed meat from the bone. The fluid jet is preferably a water jet but it may include solids, such as, ice in water or it may be a water, ice on solids in air type jet and it is preferred that the jet is directed obliquely to the interface. Preferably the bone (or bones) is mounted for rotation such that meat pieces will be peeled from the bone by centrifugal or centripetal force. It is also preferred that the peeling is performed such that the meat pieces are moved away from the* bone, to a position remote from the bone to minimise contamination with the fluid jet. . The present invention may be applied advantageously with respect to removing meat from carcass necks, particularly necks such as sheep or mutton necks having a substantially circular cross section and a substantially centrally located spinal canal. Accordingly in one embodiment of the invention there is provided a method of stripping meat from necks comprising- (i) mounting a bone or bones to a rotatable mount; (ii) rotating the mount; (iii) directing a liquid jet obliquely at the bone or bones at a meat bone interface; (iv) moving the fluid jet in a reciprocating manner relative to said rotatable mount during applicati of the liquid jet to thereby progressively strip meat from the bone or bones whereby the bond between the meat and the bone(s) is severed at said interface and the severed meat is peeled awa therefrom. It is also preferred that the fluid jet be mounted on a traversing assembly whereby it may travel along the neck as th latter is rotated on the mounting, removing meat progressively from one or each end towards the opposite end. The mount may may be a spindle adapted to pass through the spinal canal of th neck to a support frame. The invention also provides apparatus for stripping meat from bones including: mounting means for mounting of a bone or bones; a fluid jet; and support means carrying said fluid yet whereby in use said fluid jet is directed at a meat-bone interface to sever the meat therefrom and peel severed meat away from the bone{s) . The mounting means is suitably rotatable comprising a rotatable drum or carousel as hereinaf er described or alternatively the aforementioned spindle. The support means is suitably the abovementioned traversing assembly which preferably includes a transversing sleeve carrying the fluid jet mounted to a mounting shaft. The necks of larger carcasses are split into two halves during normal dressing operations. These necks require a different method of mounting to provide suitable rotation in contrast to. a mounting spindle which is suitable for a complete neck bone as described above. Typically a number of these necks could be mounted around the periphery * of a rotating drum, such that the fluid jet(s) is directed towards the bone/meat interface and traversed parallel to the axis across the rotating necks, thus achieving a similar situation as the rotating unsplit necks. As stated above preferably the fluid jet extends obliquely with respect to its direction of traverse. Of course, if desired, the fluid jet could be supported at a fixed station, arranged to oscillate if desired, and the bone mounting could carry the bone to be processed past the fluid jet. In order that this invention may be more readily understood and put into practical effect, reference will now be made to * the accompanying drawings which illustrate preferred embodiments of the invention herein: FIG 1 is a diagrammatic view of one form of deboning apparatus suitable for use with sheep or mutton necks; FIG 2 illustrates diagrammatically the operation of a water jet cutter, stand-off distance (y) and length of effective cutting jet (L); FIG 3 is a diagrammatic view of an alternate form of mounting suitable for use with split necks, eg. beef and th like; FIG 4 is a diagrammatic view of a method to increase production rates over the single spindle units shown in Figures 1 and 2; and FIG 5 is a diagrammatic view of another form of deboning apparatus for use in the present invention. Referring to FIG 1, it will be seen that the deboning apparatus 10 includes an enclosure 11 in which is supported a vertically extending spindle 12 which extends upwardly from a fixed lower bearing assembly 13. (Note: The shaft may be set at any suitable angle other than the vertical mentione provided the jet is traversed parallel to the axis of the spindle). As the neck 14 is not perfectly concentric with the spinal cavity 15, through which the spindle passes, a removable top bearing 16 is provided to stabilize the shaft. A supporting base 17 is fixed to the spindle 12 to impart rotation to the neck 14. The spindle is adapted to be rotated at about 1500 RPM but of course this could be varied as desired. Preferably the speed of rotation is not reduced to below the rate necessary to fling the meat pieces out from the bone and preferably to the enclosure walls 11. In this embodiment the cutting means is a water jet assembly 18 mounted on traversing means 19 adapted to carry the jet assembly 18 from a cutting position at the top of the neck in an axial direction towards the bottom of the neck. The cutting jet is arranged at an angle Q with respect to the neck 14 such that the j t strikes the meat/ bone interfaces from above thus providing clear access to the interface 20 as the meat is flung away. It also prevents the jet from cutting into the meat to be removed which would reduce the size of the meat pieces removed. Preferably the jet angle θ is in the range between 20° and 35° hut this range may be increased to 10° to 50° while still maintaining reasonable meat pieces size. If smaller meat pieces are required this range can be varied as desired. Traversing means 19 is vertically reciprocable on a mounting shaft 19A. There is also shown jet housing 19B and interior chamber 19C which converges as shown to form a jet orifice 19D of restricted dimensions. The traversing speed is adjustable for use with different articles, however it is suitably set to a maximum that allows the water jet to cut effectively and provide complete removal of the meat from the bones. For mutton necks for example, a traversing speed in the range of 10 to 100 mm/sec could be used with a spindle rotation speed in the range of 500 to 2000 RPM. Of course the water jet configuration must be optimized. The water jet pressure and the flow rate will be dependent upon jet orifice size. The combination of pressure and flow rate must be sufficient to sever the meat from the bone but preverably not so low as to cause flooding and washing of the meat. The combination of pressure and flow rate must not be so high that the water jet will cut the bone, since this would result in the production of a lower quality material. The jet water flow rate should be minimized to reduce power and water consumption. Preferably the jet orifice is in the range of .025mm to .127mm diameter. For such jets, typically a water pressure in the range of 7000 to 70,000 Kpa and above may be used together with a flow rate of between 3 litres to 10 litres/min. In order to provide efficient cutting by the water jet, it is also necessary that the jet stand-off £ distance be maintained within predetermined limits. Referring to FIG 2 it will be seen that the jet has an effective cutting length "L" extending from a position 21 spaced from the jet orifice 22 to a position 23 prior to the water jet dispersing. This effective cutting length can be increased by adding long chain polymers to the water. However they would have to be chosen for applications in which such additives would not be considered as undesirabl food additive or chemically react with the product and or equipment. In a typical sheep deboning installation the above ranges may be used in apparatus for deboning necks including a mounting spindle rotatable at 1500 RPM together with a jet traversing speed of approximately 60 mm/sec. This should result in a cycle time of approximately 8 seconds per neck. FIG 4 shows the option of a carousel unit for higher production rates. Preferably as a first step the sheep or mutton neck is manually deboned as part of the carcass to remove easily accessible meat therefrom. The partially deboned neck is then severed from the carcass frame, placed in the above deboning installation and approximately a further 0.3 Kg of large meat pieces can be recovered together with approximately .05 Kg of smalle meat pieces. This would result in a daily production of up to 1,000 Kg of additional meat product for a typical works that processes up to 4,000 sheep per day. Furthermore the additional product has a sale value much greater than if sold in the form of complete sheep or mutton necks for rendering as bone-meal or as paste recovered from an extrusion type machine. The meat removed from the neck is preferably conveyed away from the enclosure as quickly as possible in order to minimize water contamination, and suitable drain means are provided to ensure quick draining of the water. The meat may be removed from-fixed enclosure walls by the use of automatic wall scraping means or of course the enclosure walls could be constituted by conveyor portions adapted to convey the meat to a collection station. The drum type mounting assembly 25 illustrated in FIG 3, is adapted for use with cattle necks 26 and the like which are non-circular in section and which are split prior to being located in spaced relationship about the drum assembly 25. Retaining bars 27 extend about the drum 25 to prevent the necks being flung therefrom as the drum is rotated. Of course multiple water jets could be used if desired and different jets and water flow conditions may be required to compensate for the varying stand-off distance between the nozzles and the various parts of the split necks. The necks 26 are manually loaded onto mounting assembly 25 and retained in place thereon by re¬ taining bars 27 with the necks 26 abutting the external surface 28 of mounting assembly 25. There is also shown drive spindle 29 for the drum 25 and this is a high speed spindle attached to an appropriate drive means (not shown). The necks 26 may be unloaded from drum 25 when required. Suitably the necks 26 are half necks. There is also shown water jets 30 which are inclined to a vertical axis as shown for the reasons described previously and there may be two or three of jets 30 arranged about the periphery of drum 25 when required. Jets 30 as described previously, act as cutting jets which strike the meat/bone interface and achieve clean separation between meat and bone. The meat may be collected in a suitable receptacle (not shown). In FIG 4 there is shown a carousel or drum 31 mounted on spindle 32 which may be oriented in a vertical or horizontal orientation when required. There are also shown four work stations 33, 34, 35 and 36 which are separated by partitions 37 as shown. In this context it is important to realise that spindle 32 is an indexing spindle and is actuated by appropriate means (not shown) to only rotate a quarter of a ___ turn or circle, when required. There is also shown jet 38 oriented at an angle to a vertical axes as shown and which functions as previously described. Work station 33 is a station for removal of meat or neck 39 from mounting spindle 40. There is also provided an opportunity to clean work station 33. Work station 34 is a loading station where neck 39 may be loaded onto their respective mounting spindles 40. Work station 35 is for application of jet 38 and in this station spindle 40 is rotated at high speed which is typically 1500 r.p.m. by suitable drive means (not shown). At work station 36, spindle 40 may be retracted through lower plate 41 of carousel 31 as shown, allowing neck 39 to be ejected from carousel 31 by appropriate means (not shown). When spindle 32 is oriented in a horizontal axis there is no need for a specific ejection means as is the case when spindle 32 occupies a vertical axis as in the former situation the neck 39 may fall away by gravity to be collected in a suitable receptacle (not shown) . Spindle 39 has a pointed or skewered end 42 and is mounted in bearing 43 as shown. It also has a base disc 44 which abuts the underside of plate 41 in work stations 33, 34 and 35. It also may have a top bearing assembly as shown in-FIG 1, which has not been shown for reasons of clarity. In FIG 5, there is shown an arrangement for the stripping of meat from necks 26, which are split before being mounted on a disc assembly 45 as shown. Water jet 46 is also shown and it will be appreciated that two or more jets may be utilized for high production rates if necessary. Disc 45 has central boss 47 and peripheral lip 48 for releasably retaining the half necks 26 as shown. Disc 45 is mounted on central drive spindle 49 and there is also shown bearing assembly 50. Necks 26 may be loaded or unloaded from disc assembly 45 when required. It will also be appreciated that the invention also includes within its scope multiple assemblies of the unit assemblies shown in FIGS 1-5 for obtaining of higher production rates when required.

Claims: The claims defining the invention are as follows: 1. A method of stripping meat from bones including directing a high pressure fluid jet at a meat-bone interface to sever the bond therebetween and peel the severed meat from the bone. 2. A method of stripping meat from bones as claimed in claim 1 wherein the fluid jet is a liquid jet which is directed at an oblique angle to said interface. 3. A method as claimed in claim 1 or 2 wherein a bone or bones is mounted for rotation so that after application of the fluid jet the severed meat may be peeled away from the bone(s) by centrifugal or centripetal force to a position remote therefrom. 4. A method as claimed in any preceding claim wherein the bone or bones is a sheep or mutton neck having a substantially circular cross-section and a substantially centrally located spinal canal. 5. A method as claimed in any preceding claim wherein the fluid jet moves in a reciprocating manner relative to the bone or bones during application of the high pressure fluid jet. 6. A method as claimed in claim 5 wherein the fluid jet reciprocates in a direction substantially parallel with a longitudinal axis of the bone or bones. 7. A method as claimed in claim 5 wherein the fluid jet reciprocates in a direction substantially at right angles to a longitudinal axis of the bone or bones. 8. A method of stripping meat from bones including the steps of: (i) mounting a bone or bones to a rotatable mount; (ii) rotating the mount; (iii) directing a liquid jet obliquely at the bone or bones at a meat bone interface; OMPI -_• (iv) moving the fluid jet in a reciprocating manner relative to said rotatable mount during applic¬ ation of the liquid jet to thereby progressively strip meat from the bone or bones whereby the bond between the meat and the bone(s) is severed at said interface and the severed meat is peeled away therefrom. 9. Apparatus for stripping meat from bones including: mounting means for mounting of a bone or bones; a fluid jet; and support means carrying said fluid jet whereby in use said fluid jet is directed at a meat-bone interface to sever the meat therefrom and peel severed meat away from the bone(s) . 10. Apparatus as claimed in claim 9 wherein the mounting means is rotatable. 11. Apparatus as claimed in claim 9 or 10 wherein the support means is a traversing assembly whereby the fluid jet is adapted for traversing or reciprocatable movement relative to the mounting means. 12. Apparatus as claimed in any one of claims 9 to 11 wherein the fluid jet is attached to the support means so that it is directed obliquely to a longitudinal axis of the mounting means. 13. Apparatus as claimed in any preceding claim wherein the mounting means is an elongate spindle associated with upper and lower bearing means at each end thereof. 14. Apparatus as claimed in any one of claims 11 to 13 wherein the traversing assembly includes a traversing sleeve carrying the fluid jet mounted to a mounting shaft. 15. Apparatus as claimed in claim 14 wherein the fluid jet is oriented at an angle of between 10 and 50° to the axis of said mounting shaft. "&URE OMPI • " WIPO ___ 16. Apparatus as claimed in claim 15 wherein the fluid jet is oriented at an angle of between 20° and 30° to the axis of said mounting shaft. 17. Apparatus as claimed in any one of claims 13 to 16 further including an enclosure for supporting the upper and lower bearing means. 18. Apparatus as claimed in claim 10 wherein the mounting means is a rotatable drum adapted for mounting of a plurality of neck bones to an external surface thereof and there are provided one or more fluid jets arranged about the periphery of the drum. 19. Apparatus as claimed in claim 10 wherein the mounting means is a rotatable carousel having a plurality of open compartments or work stations separated by partitions for mounting of a respective neck bone. 20. Apparatus as claimed in claim 19 wherein said carousel is mounted on a rotatable spindle adapted to function as an indexing spindle and thereby rotate through portion of 360° corresponding to the circumferential length of a respective compartment. . 21. Apparatus as claimed in claim 20 wherein a first compartment functions as a loading station, a second compartment functions as a stripping station and a third compartment functions as a meat removal station. 22. Apparatus as claimed in any one of claims 19 to 21 wherein there are provided mounting spindles for neck bones in each compartment which are releasable therefrom. 23. Apparatus as claimed in. claim 10 wherein the mounting means is a rotatable disc mounted on a central drive spindle and adapted for mounting thereon of a plurality of bones which are attached to the disc in a radially oriented fashion. OMPI

Inventors: WESCOMBE GRAEME LESLIE JAMES, WESCOMBE, GRAEME, LESLIE, JAMES
Applicants: COMMW SCIENT IND RES ORG, COMMONWEALTH SCIENTIFIC AND INDUSTRIAL RESEARCH OR
Application year: 1984
Main classification: A22C17
IPC codes: A22C17