Method and apparatus for cutting wings from the body of slaughtered poultry, particularly broilers
The present invention relates to a method for cutting wings from the body of slaughtered poultry, particularly broi- lers, and of the type described in the introductory part of claim 1.
For a long time it has been common that slaughtered poul¬ try, for instance broilers, are marketed as oven-ready, and within the latest years it has also become common to market cut-up broilers. Hereby a wish from the consumers primarily is satisfied; but also by a factory cutting up of poultry a better exploitation of slaughtered poultry is obtained, be¬ cause it hereby has become possible also to sell poultry with minor defects, or poultry having got minor damages by the mechanical slaughtering proces.
There exists a great difference in price of the varoious cut-ups and for instance therefore, it is of great impor- tance that the cut-up is done in an anatomic correct way, so that the most expensive pieces of meat, for example the breast meat of the broilers, remain intact, that is having the highest possible weight. And seen from a veterinary authority requirement it is also of great importance, that the cut-up is done anatomically correct, so that a minimum cut of bones will occur, as eventual sanitary pernicious growth of bacteria has the greatest tendency to occur where the bone marrow is exposed.
The invention has for its purpose to provide an improved method for cutting of wings from the body of slaughtered poultry, and which by simple provisions makes possible an anatomic correct cut of wings from slaughtered poultry.
SUBSTITUTE SHEET
The method according to the invention is distinctive in that the body is conveyed towards said position with the back side first and is raised backwards/upwards by means of central guiding means, that the wings are caught and spring loaded are lead outwards/downwards proportional to the body, that the body is conveyed between preferably sta¬ tionary knife means being adapted to cut through the skin near the basis joint of the wings, to expose the big ten¬ dons between the body and the wings and to press the breast meat inwards against the body, that said tendons are cut through by means of preferably rotating knife blades, so that the joint bones of the wings momentarily are pulled free from the basis joints, and that the wings finally are cut totally from the body by passage of said knife bla- des.
Hereby it can in a simple way be secured, that the wings are cut in an anatomically correct way at the basis joints without damaging the joint bones of the wings. By pressing the breast meat towards the body it is furthermore obtained that any breast meat is cut off together with the wings. It is especially important, that the lower, big tendons be¬ tween the wings and the body are streghtened in proportion to the body by means of the behind/downwards turned pull, so that the joint bones of the wings by cutting of the strenghtened tendons monemtarily are jerked from the basis joints, so that the rotating knife blades unhindered get plenty of room to totally to cut free the wings.
In order to further optimize the method according to the invention it may be advantageous that the wings are braked in proportion to the body, so that said outwards/downwards directed pulls in the wings furthermore get a rearward di¬ rected force component, so that said tendons between the wings and the body are further streched.
The invention also relates to an apparatus for carrying out the method according to the invention, which is adapted to co-operate with a conveyor, in which the slaughtered poul¬ try, for instance broilers hanging in the legs successively are conveyed with the back first towards the apparatus, which comprise cutting means being adapted to cut the wings from the body, said apparatus is distinctive in comprising central guiding means being adapted to support the back of the broiler body mainly in lying position, guiding means at each side of the central guiding means adapted to guide the wings in preferably movable wing holding means, which near the entrance ends are pivotally arranged on mainly vertical swing axis, and which in a distance therefrom are connected with spring means being adapted to influence the wing hol- ding means to be swung away from each other, that is in the moving direction to increase the mutual distance between the wing holding means, stationary knife means being adap¬ ted to cut through the skin near the basis joint of the wings, to expose tendons between the wings and the body and to press the breast meat inwards against the body, and pre¬ ferably rotating knife blades being adapted to first cut the said tendons, so that the wing bones momentarily are pulled from the basis joint, and afterwards to cut the wings totally from the body.
By means of simple provisions an apparatus is hereby obtai¬ ned suitable for practise of the method according to the invention, so that it becomes possible to cut the wings from the body in an anatomic correct way, that is without the wing bones being damaged. From an economical point of view it is furthermore important that the breast meat by means of stationary knife organs from both sides are pres¬ sed inwards towards the body and are kept free by the rota¬ ting knife blades, so that an increase in weight of the breast meat is obtained, which as earlier mentioned makes up the most demanded and expensive part of the broiler.
The said central steering organs of the apparatus according to the invention may expediently consist of a level adjust¬ able mainly horizontal arranged rail, which from a lower positioned entrance end streching in a bow upwards to the horizontal run, and which has V-shaped cross section which is open upwards.
And preferably the apparatus is such provided that the en¬ trance guiding means consist of from above in a bow down- wards leading end parts of level adjustable mainly horizon¬ tal, stationary guiding rails being adapted to fix "elbow joints" of the wings against the preferably movable wing holding means, as said guiding rails are stretching along the top side of the wing holding means.
In a preferred embodiment for the apparatus according to the invention the wing holding means consist of endless chains, of which upper runs of the chains is lead in guid¬ ing recesses in upper edges of vertical guding plates in such a manner that the upper runs of the chains are strech¬ ing parallel with said guiding rails close along these, so that fthe "elbow joints" of the wings may be fixed between the guiding rails and the single chain link, that the ver¬ tical guiding plates near the entrance end are pivotally arranged on vertical swing axis, and that the guiding pla¬ tes in a distance therefrom are link-connected with said spring means in such a manner that the guiding plates and the wing holding means are affected to be swung out in a preferably symmetrical manner from each other on said swing axis, so that the mutual distance between the wing holding means is increased in the moving direction for successively tightening out of the wings in relation to the body.
In a simple manner the apparatus may be such provided that the endless chains of the wing holding means are drive con¬ nected with the belonging superior conveyor via separate
axle connections and angle gears, which at the same time consist reduction gears, as the working speed of the chains is lower than the working speed of said conveyor, in which the broilers are conveyed, and that said swing axis for the guiding plates of the chains are placed aligned with the axis of said drive axle connection.
Expediently the stationary knife means consist of fixed, adjustable knife blades, which at opposite sides of the bo- dy are placed at the top side of inner end parts of the wings, that inwardly directed cutting edges of the knife blades at the passage of the body are able to cut through the skin in front of the basis joint of the wings and to expose the large lowermost tendons between the wings and the body and that the knife blades themselves are able to press the breast meat inwards against the body.
In order to obtain a further optimized guidance of the body during the passage of the apparatus the central guiding means also comprise secondary guiding means which at both sides of said rail consist of thin guiding rods being adap¬ ted to support the body immediate within the basis joint of the wings in front of said stationary knife menas and in front of said knife blades.
And in a particular simple manner the preferably rotating knife blades are adapted to from stationary, inclined posi¬ tions at opposite side of the body inside said secundary guiding rods preferably at the same time first to cut the tightened out tendons between the wings and the body, so that the wing bones momentarily are pulled from the basis joints and afterwards to cut the wings totally from the bo¬ dy.
In the following the invention is described in more details with reference to the drawing, in which:
Fig. 1 shows a very simplified principle sketch for illu¬ stration of method and apparatus according to the inven¬ tion,
Fig. 2 shows also a principle sketch for illustration of method and apparatus according to the invention.
Fig. 3 shows a side view - partly in section - of a left part of a preferred embodiment for the apparatus according the invention,
Fig. 4 shows a view - seen from above - of the apparatus part shown in Fig. 3 according to the invention, while
Fig. 5 shows a detail view of a part of the apparatus shown in Fig. 3 and 4 according to the invention.
A slaughtered broiler 2 hanging in the legs 4 in a conveyor is conveyed - as shown in Fig. 1 - with the backside of the body turned forwards in the moving direction (upwards in Fig. 1) towards a wing cutting apparatus 8, where the broi¬ ler 2 in an approximate lying position supported by a cen¬ tral V-shaped rail 10 is guided into an apparatus 8, which at both side of the V-rail 10 comprises wing holders 12. They both consist of horisontal guiding rails 14 placed above upper runs 16 of endless chains 18 and being secured in an adjustable manner at opposite exterior sides of ver¬ tical guiding plates 20, which along upper horizontal ed¬ ges have longitudinal guiding recesses 22 for the endless chains 18. The guiding plates 20 are near an entrance end 24 pivotally arranged on vertical swing axis 26, so that the guiding plates 20 in order to stretch out the wings of the broiler in relation to the body 6.
In Fig. 1 the wings 28 are fixed in the wing holders 12, as the wings inside "the elbow joint" are fixed between the
guiding rails 14 and single chain links of the chains 18, which as mentioned are guided in the horizontal guiding recesses 22 along the upper sides of the guiding plates 20. These are - as shown in Fig. 2 - in a distance from the entrance end 24 link-connected with a common, central spring mechanism 30, being adapted to in a preferably sym¬ metrical manner to influence the guiding plates 20 with outwards-directed forces, so that the guiding plates are swung outwardly on the swing axis 26, and so that the wings 28 fixed in the wing holders 12 successively are strenghte- ned out in relation to the body 6.
The spring mechanism 30, which comprises a cylindrical guiding rod 32 for a screw pressure-spring 34, a tightening nut 36 and at the guiding rod 32 a displaceable arranged slide member 38. The latter being connected with both guid¬ ing plates 20 by means of link rods 40 which at opposite ens are pivotally connected with the slide member 38 and the guiding plates 20. The spring mechanism 30 is also seen in Figs. 3 and 4 showing for clearness only the left part (in the working direction) of a preferred embodiment for a wing cutting apparatus according to the invention.
The endless chain 18 lead around the guiding plates 20 is drived by means of a chain wheel 42 which at the entrance end 24 of the guiding plates 20 is pivotally arranged be¬ tween bearing plates 44, and which is drive-connected with a drive axle 46 via an angle gear 48 which at the same time consists a reduction gear, as the wing holding chains 18 as mentioned in the introductory part in order to also perform a rearwards directed in the wings 28 are moved with reduced speed. The swing axis 26 for the guiding plates 20 are i- dentical with the drive axle 46 which is pivotally arranged in a support bearing 49, which again is supported on hori- zontal carrying rods 50, also supporting the other not shown part of the apparatus 8. Furthermore the guiding pla-
tes 20 are supported via the link rods 40 by the spring mechanism 30, which is secured projected from an upstanding bracket 52 of a lower frame member 54 also supported by ho¬ rizontal carrying rods 56, which at each side of the guid- ing plates 20 also comprises holding members 58 for verti¬ cal posts (not shown) for motor-driven, rotating knive bla¬ des 60 (Fig. 2) .
The horizontal, central V-shaped rail 10 is secured in an adjustable manner to the rearside of the bracket 52, to which also secondary guiding rods 62 with curved front end parts 64 are secured. And as also shown in Fig. 3 the cen¬ tral V-rail 10 is provided with a curved front end part 66, so that the body 6 of the broilers easier may be guided on- to the V-rail 10. Finally is also the front end part of the steering rails 14 provided with a arched end part 68, so that the wings 28 at the entrance end easier may be guided in between the chains 18 and the guiding rails 14.
Both cutting operations, mentioned in the introductory part, namely the precutting by means of the stationary kni¬ fe blades 70 (Fig. 2) , the cut of the large wing tendons with the rotating knive blades 60 and the final cut of the wings 28 are made in front of the secundary guiding rails 62, that is in front of the rearmost end of the guiding plates.
The stationary knife blades 70 are as shown in Fig. 2 pla¬ ced in an angle of about 15° in relation to the center plan of the apparatus in the moving direction, and in an angle of about 6.5° in relation to horizontal, and in an angle of about 78° in relation to vertical - as seen from the narrow side of the knife blades. Hereby the stationary knife bla¬ des 70 are able to serve more functions at the same time, namely to cut through the skine in front of the basis joint between the body 6 and the wings 28, to expose the large.
lower wing tendons and to press the breast meat inwards a- gainst the body 9 , so that the f inal cut by means of the rotating knife blades 60 may be done unhindered, that is without the wing joints at basis being damaged.
Also the rotating knive blades 60 may be angle-adjusted in a specif ic manner , which however is measured from the rotation axis of the knife blades - as follows : About 35° in relation to vertical (posts) and about 55° in relation to a vertical center plan through the apparatus .
It should be mentioned, that the apparatus according to the invention without noticeable adjustment is able to cut wings from the body of broilers or chickens of various si- ze . The spring mechanism 30 shall preferably be adjusted so that the guiding plates 20 and therewith the wing holding means 12 are able to strenghten out the wings optimum of broilers with a difference in weight of about 800 g; how¬ ever the apparatus may be adjusted to handle broilers with a weight from about 800 g and up to about 2 , 500 g.