Method and apparatus for filleting the breast piece of slaughtered poultry

Abstract: The invention relates to a method for filleting the breast piece of slaughtered poultry comprising at least the sternum (4) and the wishbone (5) defined by both clavicles, wherein the breast piece is supported and the breast flesh is cut loose from the sternum and the wishbone by means of cutting means. According to the invention previously to cutting loose the breast flesh, the wishbone is pressed inwardly as seen relatively to the breast piece. Further the invention relates to an apparatus for carrying out the method according to the invention, comprising a pressure means (12) movable to and fro which in an operative position can engage the wishbone (5) in order to press it inwardly relative to the breast piece (8).

Description: The invention relates to an apparatus for filleting the breast piece of slaughtered poultry comprising at least the sternum and the wishbone defined by both clavicles, with supporting means for supporting and transferring the breast piece in a first direction, means for loosening the breast flesh from the sternum and the wishbone, and pressure means for pressing the wishbone inwardly as seen relatively to the breast piece previously to loosening the breast flesh. Such an apparatus is known from EP-A-0 591 741 and includes a quite complicated construction in order to effect pressing the wishbone inwardly with respect to the breast piece prior to loosening the breast flesh from the sternum and the wishbone. The wishbone is pressed inwardly in orderto prevent that bone remainders will be present in the breast flesh obtained. There are many reasons for the presence of such bone remainders. The poultry from which the breast piece originates principally are young chickens which are not yet fully grown. As a result bone fractures may occur during several stages from little chicken until finished end product. Already during capturing chickens fractures may occur in the not yet fully grown wishbone because the chickens wildly flap their wings. Also during stunning, previously to slaughtering, jerky muscle tensions sometimes result in undesired bone fractures. The successive plucking of slaughtered chickens with mechanical plucking fingers is another source of bone fractures. Finally bone fractures may result from the automatic ready-to-cook machines with which the slaughtered chicken is made ready to cook. Eviscerators also belong to this category of machines. As a result isolated fragments of the wishbone may remain in the breast flesh, which, of course, is undesired. It is the object of the invention to provide an alternative apparatus with which it is possible to obtain the breast flesh which is substantially free from bone remainders originating from the wishbone. The apparatus according to the invention is characterized in that the pressure means are movable to and fro relative to the supporting means in a down-respectively upward direction perpendicular with respectto the first direction, wherein in an operative position the pressure means can engage the wishbone in order to press it downwardly relative to the breast piece. According to a preferred embodiment of the apparatus according to the invention the pressure means is provided with a cutting edge at its side meant for engaging the wishbone. The advantage of such a cutting edge is that the pressure means can directly engage the wishbone without any breast flesh being present therebetween. For, the cutting edge enables the pressure means to cut with its respective side through the breast flesh until engaging the wishbone and pressing it away. Further it is preferred that the pressure means is shaped as a loop-like brace attached to the end of an operating rod movable in the down-respectively upward direction. The shape of the loop-like brace may be such that the tip of the wishbone, where the two clavicles meet each other, is engaged. In practice it appears that often this part of the wishbone remains as a bone fragment in the breast flesh. Due to the special shape of the loop-like brace it is guaranteed now that this section of the wishbone is pressed inwardly also and will not be present in the breast flesh cut loose. However it is possible too, that the loop-like brace has such dimensions that it can pass around the wishbone and at its side facing away from the cutting edge comprises a plate section, whereas the cutting edge is interrupted at that part of the loop-like brace which crosses the wishbone. Together with the plate section the loop-like brace in a way defines a reversed cup receiving the wishbone and the flesh in the immediate vicinity thereof. Due to the interruption in the cutting edge at that part of the loop-like brace which crosses the wishbone, the wishbone remains connected with the carcas and is only pushed out of reach of the filleting means when the brace is engaged. With this embodiment it is prevented in an optimised way that the bone remainders are present in the breast flesh cut loose. However with this embodimentthe yield of flesh is smaller. An additional advantage of this embodiment is that by means of the tip of the loop-like brace a tendon extending between the tip of the wishbone and the sternum can be cut through. The operating rod may be movable to and fro in several ways, for example by means of a follower roll attached thereto which cooperates with a curved track. However, other driving mechanisms are conceivable to. In correspondence with a different embodiment the apparatus according to the invention is characterized by securing means which are movable between a first position in which they can engage the wing joints and a second position in which they disengage the wing joints. These securing means take care of a well defined positioning of the wing joints such as to further improve the operation of the apparatus. Finally a special embodiment of the apparatus according to the invention is mentioned wherein the pressure means is carried by the supporting means. In such an embodiment the pressure means basically moves synchronously with the supporting means which in turn in a way known per se, may be part of an endless round going conveyor. Hereinafter the invention will be elucidated referring to the drawing, in which an embodiment of the apparatus according to the invention is illustrated. Fig. 1 shows schematically a side elevational view of a part of an embodiment of the apparatus according to the invention, with breast piece attached thereto, in a first position; fig. 2 shows the apparatus of fig. 1 in a second position; fig. 3 shows the apparatus of fig. 1 in a top plan view; fig. 4 shows in a top plan view according to fig. 3 an amended embodiment of the apparatus, and fig. 5 shows on an enlarged scale according to V-V in fig. 4 a cross-section of the loop-like brace. Fig. 1 shows in a side elevational view a section of an apparatus for carrying out the method according to the invention with a supporting means for a breast. piece of slaughtered poultry shaped as a carriage 1. This carriage 1 can be part of an endless conveyor which in the present case has been indicated schematically by chains 2, and using which a large amount of carriages 1 follow an endless round going track. A breast piece 3 schematically indicated in the figures, supported onto the carriage 1 comprises at least the sternum 4 and the wishbone 5 formed by both clavicles. In the situation shown also the coracoids 6 and part of the ribs 7 are shown. The respective breast piece is completed by the breast flesh 8. The shape of the carriage 1 is adapted to the expected shape and dimensions of the breast piece. Depending upon the destination of the breast piece and the products obtained therefrom the breast piece can be larger or smaller than represented. In the carriage an operating rod 9 is provided which is movable to and fro relative to the carriage 1. Although this movement to and fro of the operating rod 9 may be realised in many ways, in fig. 1 and fig. 2 a constructive embodiment is represented according to which a follower roll 10 is attached to the lower most end of the operating rod 9, said roll being adapted to co-operate with a stationary curved track 11 indicated in dotted lines. In the non-operative position of the operating rod illustrated in fig. 1 a pressure means 12 attached to the upper end thereof is positioned just above the breast piece. In this position a breast piece 3 can be positioned onto the carriage 1 easily. When the conveyor, represented by chain 2, moves on the carriage 1 the operating rod 9 will be moved downwardly to an operative position due to a co-operation between the follower roll 10 and the curved track 11, such that the pressure means 12 will engage the breast piece. As a result the breast piece 3 will firstly be clamped onto the carriage 1. A continued downward movement of the operating rod 9 relative to the carriage 1 will result in pressing the wishbone 5 downwardly relative to the breast piece 3. Like this the situation is obtained as indicated schematically in fig. 2. One can see that the follower roll 10 is at a section of the curved track 11 positioned at a lower level than the section of the curved track 11 at which the follower roll 10 is according to fig. 1. In the position shown in fig. 2 the breast flesh of the breast piece 3 can be cut loose by appropriate cutting means without the risk that the breast flesh cut loose comprises bone fragments which originate from the wishbone. As appears clearly from fig. 3 the pressure means 12 is shaped as a loop-like brace not only engaging the clavicles defining the wishbone 5 but also the connecting piece between both clavicles (i.e. the tip of the wishbone). As a result also this tip of the wishbone which is often present in the breast piece as an isolated bone fragment, will be pushed out of reach of the cutting means effectively. Preferably the pressure means 12 comprises a cutting edge 13 at its side meant for engagement with the wishbone 5. Like this the wishbone 5 can be pressed downwardly without simultaneously pressing downward part of the breast flesh. Resulting from this the yield during cutting loose the breast flesh is increased. The cutting means applied for cutting loose the breast flesh 8 from the breast piece 3 are not illustrated in the drawing because these are of a type known per se, however such that now the shape thereof may be chosen in such a way that a larger part of the breast flesh is cut loose from the breast piece because there is no risk anymore of bone fragments being present in the breast flesh cut loose. In the amended embodiment according to fig. 4 the pressure means is shaped as a loop-like brace 15, however it is bigger than the loop-like brace 12 according to fig. 3. The loop-like brace 15 has such dimensions that it can pass around the wishbone 5. At that part 16 where the brace crosses the wishbone 5 the cutting edge 19 (see fig. 5) of the brace 15 is interrupted (not shown) such that the wishbone is not cut loose from the remainder of the carcas. As appears clearly from fig. 5 the brace 15 comprises a plate section 18 at its side facing away from the cutting edge 19, such that in a way a reversed closed cup is defined into which the wishbone 5 is largely housed. Simultaneously with moving downward the wishbone 5 using the brace 15 also a part of the breast flesh is moved out of reach of the filleting means to be applied later. Furtherthe tip of the brace 15 cuts through a tendon extending between the tip of the wishbone 5 and the sternum. Due to the mentioned interruptions in the cutting edge 19 the wishbone 5 remains attached to the carcas. Further in fig. 4 schematically securing means 17 are indicated which in correspondence with the double arrows are movable to and fro between a first position (indicated in fig. 4) in which they engage the wing joints of the breast piece and a second position in which they disengage the wing joints. These securing means 17 in the first position secure the position of the breast piece in a defined way such that the operations to be carried out are reproducable. The invention is not limited to the embodiments described before which can be varied widely within the scope of the claims. As mentioned before a solution in respect of the to and fro movement of the pressure means 12 and operating rod 9, respectively, other than the application of an assembly comprising follower roll and curved track may be provided. Driving means housed in the carriage 1, such as a cylinder-piston assembly or alike, are possible too. Further it is not absolutely necessary that the pressure means is attached to the carriage 1. It is also possible that the pressure means belongs to an external driving mechanism by means of which the pressure means moves synchronously with the carriage 1 and the breast piece provided thereon for a limited time while carrying out its operation. Further it is noted that basically it is conceivable to provide a stationary supporting means for the breast piece instead of carriage moved on by the conveyor, in which case the cutting means move along the stationary supporting means which have breast pieces provided thereon. Finally the shape of the pressure means may differ from the loop-like brace described before.

Claims: Apparatus for filleting the breast piece (3) of slaughtered poultry comprising at least the sternum (4) and the wishbone (5) defined by both clavicles, with supporting means (1) for supporting and transferring the breast piece in a first direction, means for cutting loose the breast flesh (8) from the sternum (4) and the wishbone (5), and pressure means (12, 15) for pressing the wishbone (5) inwardly as seen relatively to the breast piece (3) previously to loosening the breast flesh, characterized in that the pressure means (12, 15) are movable to and fro relative to the supporting means (1) in a down- respectively upward direction perpendicular with respect to the first direction, wherein in an operative position the pressure means (12, 15) can engage the wishbone (5) in order to press it downwardly relative to the breast piece (3). Apparatus according to claim 1, characterized in that the pressure means (12, 15) is provided with a cutting edge (13, 19) at its side meant for engaging the wishbone (5). Apparatus according to claim 2, characterized in that the pressure means is shaped as a loop-like brace (12, 15) attached to the end of an operating rod (9) movable in the down-resp. upward direction. Apparatus according to claim 3, characterized in that the loop-like brace (15) has such dimensions that it can pass around the wishbone (5) and at its side facing away from the cutting edge (19) comprises a plate section (18), whereas the cutting edge (19) is interrupted at that part of the loop-like brace which crosses the wishbone (5). Apparatus according to one of the claims 1-4, characterized in that the pressure means (12, 15) is carried by the supporting means (1). Apparatus according to one of the claims 1-5, characterized by securing means (17) which are movable between a first position in which they can engage the wing joints and a second position in which they disengage the wing joints.

Inventors: LINNENBANK LEONARDUS MATTHEUS, LINNENBANK, LEONARDUS MATTHEUS PETRUS
Applicants: MACHF MEYN B V, MACHINEFABRIEK MEYN B.V.
Application year: 1995
Main classification: A22C21
IPC codes: A22C21