Method and apparatus for filleting the body of slaughtered poultry

Abstract: In a method and an apparatus for automatic removal of at least an inner fillet (70) from slaughtered poultry or a part thereof before the connection between the inner fillets (70) and the carcass is broken, a separation is made in the opening bounded by the clavicle (8c; 80) and the breastbone (8b), whereupon the inner fillets (70) are at least partly scraped off from the carcass. In another method of filleting, the canalis triosseus (92) is cut open in the shoulder joint, whereupon at least the inner fillets (70) are pulled free from the carcass with the aid of the humerus (88). Previously, the connection between the membrane of the inner fillets and the breastbone (8b) in the region of the coracoideum (82) is broken. For placing a front half (132) of a slaughtered bird (126) on a carrier (138), a bird is hung by its legs on a suspension element (122), whereupon the front half (132) and the back half (134) are separated from one another except for a rear connection (136). The front half (132) is thereupon placed on the carrier (138) and the rear connection (136) is broken.

Description: The invention relates to a method and an apparatus for removing automatically at least the inner fillets from slaughtered poultry or a part thereof. The inner fillets, also called tenderloins or tenders, are a part of the bird particularly valued by consumers and therefore valuable, provided that they are of good quality. The inner fillets usually remain behind on the carcass when the outer fillets, also referred to simply as breast fillets, are removed from the carcass. In the prior art various methods and apparatuses are known for the removal of, in particular, the inner fillets from the carcass of a bird. US-A-5 314 374 discloses the removal of inner fillets from a poultry carcass conveyed on a carrier, by first cutting and plowing the inner fillets almost completely free from the carcass, and next gripping the inner fillets with a pair of jaws pulling the inner fillets free from the carcass transversely to the direction of conveyance. A difficulty in the methods and apparatuses of the prior art is that the mechanical scraping process indicated therein compresses the inner fillets to a greater or lesser extent in the longitudinal direction, whereby the flesh structure of the inner fillets is damaged. This has the consequence that the appearance of the inner fillets obtained in this manner is less attractive to the consumer and that they go off more quickly. Another difficulty in the prior art is that the membrane of the inner fillets is damaged or is left on the carcass, so that in the place where the membrane adheres to the inner fillets in the natural state a frayed meat surface structure is formed, which impairs the quality of the meat in the same way as is described above. With the usual methods, a small part of the meat of the inner fillets near the clavicle remains on the carcass after the removal of the inner fillets, because the latter must be cut free from the breastbone with due regard to a safe distance from the clavicle. If this distance is too short there is in fact a great risk that the clavicle will come into contact with a cutting or scraping element and that splinters of bone or particles of the clavicle will remain in the inner fillets. This cannot be tolerated from the point of view of product quality and liability for the product. The consequence of all this is that after the removal of the inner fillets not inconsiderable amounts of meat remain on the carcass. As an additional difficulty it should also be stated that in the methods of the prior art the inner fillets are frequently detached from the carcass in such a manner that considerable damage is done to the structure of the meat surface in the area where the separation is made. The object of the invention is to provide a method and an apparatus by means of which inner fillets can be removed mechanically and automatically from the carcass of a bird, while the greatest possible amount of meat is obtained and damage to the meat is prevented as much as possible. This object is attained according to the invention by a method wherein prior to scraping off the inner filet the membrana sternocoracoclavicularis is released by making a separation in the opening defined by the natural position of the clavicle and the breastbone. The making of a separation in this position has the consequence that absolutely no residues of meat remain behind on the carcass after the removal of the inner fillets. Before the inner fillet is scraped away from the body of the poultry the connection between the membrane of the inner fillet and the breastbone in the region of the coracoideum is preferably broken. With freshly slaughtered products this process can be carried out either before or after the breaking of the connection between the inner fillet and the clavicle in the manner described above. If the product is matured and therefore more vulnerable, it is preferred to carry out this process after the breaking of the connection between the inner fillet and the clavicle. In order to leave the membrane of the inner fillet as far as possible intact, the inner fillet is only partly scraped away from the body of the poultry, after which the part already scraped away is gripped and the inner fillet is pulled free from the body of the poultry substantially in front of the breast thereof. By leaving the membrane intact, the surface structure of the meat under it is kept intact, so that the inner fillet has an attractive appearance and will keep for a long time. According to the invention an apparatus for the automatic removal of at least an inner fillet from slaughtered poultry or a part thereof comprises a carrier for fixing thereon the poultry or a part thereof, at least comprising the breast with the inner fillets attached, separating elements for the inner fillets, which elements are adapted to be inserted, on opposite sides of the breastbone, into the openings defined by the natural position of the clavicle and the breastbone for the purpose of releasing the membrana sternocoracoclavicularis, and scraping means for scraping off the inner fillets from the body of the poultry. The carrier usually forms part of a conveyor. It may for example have the configuration described in EP-A-0 551 156. In such a case the scraping means and the separating elements may be arranged - if necessary movably - along the path of the conveyor. It is naturally also possible to install the carrier in a fixed position and to make the scraping means and separating elements movable. In a preferred embodiment the apparatus according to the invention comprises membrane separation means for breaking the connection between the membrane of the inner fillets and the breastbone in the region of the coracoideum. The membrane thus continues to cover the outer surface of the inner fillets even after they have been removed from the body of the poultry, which is advantageous for their appearance and for the keeping properties of the inner fillets. In another preferred embodiment the apparatus according to the invention comprises inner fillet removal means for gripping the inner fillet and pulling it free from the body of the poultry substantially in front of the breast thereof. The separating elements for a set of inner fillets expediently consist of two substantially parallel plates facing one another and having a free end, the plates being mounted resiliently in relation to one another and in relation to a holder, said holder being movable in a controlled manner relative to the carrier. The ends of the plates have dimensions such that they can without difficulty pass through the openings bounded by the clavicle (if present) and the breastbone. In order to be able to follow the contour of the breastbone as closely as possible, the distance between the plates is shorter than the maximum width of the breastbone. In addition, the resilient connections between the holder and the plates ensure that the plates can easily and accurately follow the contours of the breastbone. The edges of the free ends of the plates are blunt, optionally with the exception of the front side, which may be sharp, thus preventing splinters of bone from being cut off from the breastbone or the clavicle and passing into the inner fillets. In an advantageous embodiment the membrane separation means for a set of inner fillets comprise two rotatable discs extending generally in one and the same plane. By moving the discs along the rib cage of the bird, on the underside of the inner fillets, the inner fillets are propelled upwards and the connection between the membrane of the inner fillets and the breastbone in the region of the coracoideum can thus be broken. A good propelling action of the discs is obtained by providing their circumferential edge with a frustoconical shape. The circumferential edge of the discs is preferably provided with at least one radially projecting knife for an additional controlled separation of the inner fillet membrane from the breastbone. In a preferred embodiment the scraping means for a set of inner fillets consist of two scraper plates mounted resiliently at an angle to one another and to a holder, the holder being movable in a controllable manner relative to the carrier, while the scraper plates are adapted to be placed on opposite sides of the clavicle and then on the latter and to be moved along the breastbone away from the clavicle. The distance between the scraper plates is preferably shorter than the maximum width of the breastbone. By means of the abovedescribed measures a scraping action is obtained which extends over the entire surface over which the inner fillets cover the rib cage. In an expedient and simple embodiment the carriers form part of a conveyor along whose path the separating elements, the membrane separation means and the scraping means are installed. The invention is explained in more detail by reference to the drawings, in which; Fig. 1 is a front view of a shoulder joint of a bird, in which only one tendon is shown schematically; Fig. 2 shows a schematic side view of an embodiment of a filleting station according to the invention; Fig. 2a schematically shows a cross-section of the apparatus shown in Fig. 2, taken on the line IIa-IIa. Fig. 3 shows a schematic side view of an alternative embodiment of a station of the apparatus according to Fig. 2; Fig. 4a shows in perspective a schematic view of a component of the apparatus shown in Fig. 4; Fig. 4b is a schematic front view of a part of the carcass of a bird having inner fillets, to illustrate a first process; Fig. 5 is a schematic view in perspective of the carcass part shown in Fig. 4b, to illustrate a second process; and Fig. 6 shows a schematic view in perspective of the carcass part shown in Fig. 4b, to illustrate a third process carried out thereon. In the different drawings, like reference symbols designate like parts. Fig. 1 illustrates the bone connections in the shoulder joint and shows a part of the clavicle (wishbone) 80, the coracoideum (collar bone) 82 with the processus acrocoracoideus 84 at one end, the scapula (shoulder blade) 86 and the humerus (wing bone) 88 with the caput humeri 90. The tendon connection between an inner fillet and the humerus 88 is represented by a broken line 91 and passes through the canalis triosseus 92. A way to effect filleting is discussed below with reference to Figs. 2, 2a, 3, 4a, 4b, 5 and 6. Figs. 2 and 2a show two mirror-image conveyor rails 2a and 2b, between which are enclosed sliding elements 4 which can move in the longitudinal direction of the conveyor rails 2a, 2b, in the direction indicated by the arrow 5. The sliding elements 4 are mutually coupled by means of a chain 3 or the like, indicated by a dot-dash line. A mounting support 6 is fastened rotatably and tiltably on each of the sliding elements 4. Each mounting support 6, which is described in greater detail in EP-A-0 551 156, has a substantially frustoconical end on which a front half 8 of a bird can be placed and fastened. For the sake of clarity only the rib cage 8a, the breastbone 8b, the clavicle 8c and the coracoideum 8d of each front half 8 are shown schematically in Fig. 2; the inner fillets, which are situated in the transition region between the rib cage 8a and the breastbone 8b are not shown in the Figure in order to make it possible to show as clearly as possible the different components of the apparatus and the place where they act on the carcass. Three processing stations 10, 20 and 30 respectively are installed along the path of the mounting supports 6. For the sake of clarity of the drawing the processing stations 10, 20 and 30 are as far as possible shown without support elements which effect the fixing of the processing station in relation to a frame in which the conveyor rails 2a and 2b are also held. The processing station 10 is situated centrally above the conveyor rails 2a and 2b and comprises two guide strips 12, of which only one is visible in Fig. 2 and which between them leave open a slit of a width such that the upwardly projecting breast point of a front half 8 located on a mounting support 6 is guided therebetween. In the slit between the guide strips 12 is likewise situated an end of a pivotally mounted lever 14 which operates a switch 16 when the breast point of a front half 8 pushes the lever 14 out of the position shown in Fig. 2. The switch 16 thus gives a signal for the operation of the processing station 10, to which detailed reference will be made again further on. Above each guide strip 12 is situated a plate 19 provided with guide slots 18a and 18b. Between the plates 19 is enclosed a holder 21, which is shown in greater detail in Fig. 4a. The holder 21 is provided with pins 22a and 22b, which are guided in the slots 18a and 18b respectively. Outside the region of the plates 19, separating elements 24 are fastened resiliently on the holder 21. The separating elements 24 are each provided with two holes, which correspond with holes provided in the holder 21. Through the holes are pushed pins which are provided at each end of a plug 26 in order to enclose springs 28 between the plugs 26 and the separating elements 24, so that the latter can yield laterally. The edges of the separating elements 24 are usually made entirely blunt, but their front ends 24a may be provided with a cutting edge. The holder 21 is provided with a lip 32 or the like, to which an angle member 34 can be fastened. The end of the angle member 34 remote from the holder 21 is pivotally connected to the end of a piston rod 36 of a double-acting pneumatic cylinder and piston unit 38. At the end remote from the angle member 34 the cylinder and piston unit 38 is connected to the frame of the apparatus for pivoting about an axis 40. The processing station 20 comprises two discs 42, which are installed one on each side of the path of the mounting supports 6, only one being visible in Fig. 2, and which are located at a distance from each other such that the breastbone 8b of a front half 8 mounted on a mounting support 6 can pass therebetween in the direction of the arrow 5. The discs 42 are mounted on axes 44, each of which during operation is driven in such a manner that the circumferential region of the discs 42 moves, near a front half 8 passing between them, in the direction of the arrow 5. The side of the discs 42 is frustoconical and stands at an angle of about 10° to the longitudinal direction of the axes 44. At one place on the circumference a radially projecting cutting element 46 is arranged on the bottom edge of each disc. The rotation of the discs 42 is synchronized with the movement of the mounting support 6 in the direction of the arrow 5. The processing station 30 has guide strips 48 similarly to the processing station 10. Above the guide strips are installed guide walls 52 which are provided with guide slots 50a and 50b and between which, similarly to the processing station 10, a plate-shaped holder 56 provided with pins 54a and 54b is mounted so as to be slidable. Two scraping elements 58, of which the scraping front side is illustrated in greater detail in Fig. 6, are resiliently fastened to the holder 56. As shown in Fig. 6, the scrapers 58, which can be made of metal or plastics material, are installed at a short distance from each other and are provided on the front side with ends 58a bent sideways. The holder 52 is pivotally connected by means of an angle member 60 to the end of a piston rod 62 of a double-acting pneumatic cylinder and piston unit 64. At the end remote from the angle member 60 the cylinder and piston unit 64 is pivotally connected to the frame of the apparatus. The action of the apparatus will be explained with the aid of Figs. 2, 4a, 4b, 5 and 6. In the first place, as shown in Fig. 2, a front half 8 fixed on a mounting support 6 is passed through the first processing station 10. Through the operation of the lever 14 by the breastbone 8b, the switch 16 signals the presence of a front half 8 on the mounting support 6, and delivers a signal to the control system of the apparatus so that, taking into account the speed of movement of the mounting support 6 in the direction of the arrow 5, after a predetermined delay time, the cylinder and piston unit 38 is energized. This energization takes place when the upwardly projecting point of the breastbone 8b of the front half 8 has passed the front side 24a of the separating elements 24. The holder 21 of the separating elements 24 is moved in the direction of the arrow 5 and slightly tilted downwards by means of the guide slots 18a when the piston rod 36 is pushed out of the cylinder and piston unit 38, the end position reached being shown in dashed lines in Fig. 2. The resulting movement of the separating elements 24 takes place very much more quickly than the movement of the mounting supports 6. The front sides 24a of the separating elements 24 thus move downwards along the breastbone and forwards into the openings bounded by the breastbone 8b and the clavicle 8c, releasing the membrana sternocoracoclavicularis. This is elucidated in Fig. 4b, in which arrows 68 illustrate the direction of the movement of the front sides 24a of the separating elements 24. Inner fillets 70 are thus cut free from the breastbone under the clavicle 8c. The separating elements 24 are then pulled back into the starting position shown in Fig. 2. It is to be remarked here that the clavicle may have been removed earlier from the front half, in which case the term clavicle in the above is merely used to define the natural position of the clavicle. The front half, with the inner fillets 70 freed from the breastbone 8b under the clavicle 8c, then passes through the second processing station 20. The frustoconical side of the rotating discs 42 engages the sides of the inner fillets 70 and pushes them upwards, as illustrated by the arrows 72 in Fig. 5. In this action the cutting element 46 ensures that the membrane of the inner fillets 70 on the underside of the latter is cut free from the breastbone over some distance. The preprocessed front half then passes through the third processing station 30, in which the guide strips 48 bring downwards again the inner fillets 70 pushed upward in the second processing station 20. After the upwardly projecting point of the breastbone 8b of a front half 8 has passed the ends 58a of the scraping elements 58 in the third processing station 30, the cylinder and piston unit 64 is energized. The moving piston rod 62 drives the holder 56 and the scraping elements 58 connected thereto in a movement, determined by the guide slots 50a and 50b, in the direction of the arrow 5, while the holder and the scraping elements 58 tilt slightly downwards. The end position reached is shown in dashed lines in Fig. 2. The movement of the scraping elements 58 takes place very much more quickly than the movement of the mounting supports 6. In the operative position the ends 58a of the scraping elements 58 come to lie one on each side of the clavicle 8c, as illustrated in Fig. 6, so that a movement of the front half 8 on the mounting support 6 in the direction of the arrow 5 results in a scraping force, exerted substantially in the direction of the arrows 74, on the inner fillets 70 on each side of the breastbone 8b. Fig. 3 illustrates an alternative embodiment of a first processing station, in which a separation is made between the breastbone 8b and the inner fillets under the clavicle 8c. In a similar manner to that described with reference to Fig. 4a, separating means 24 are resiliently mounted on a lever 76 which is pivotable about a fulcrum 78. The end of the lever 76 remote from the separating elements 24 is pivotally connected to the end of the piston rod 36 of the cylinder and piston unit 38. When the piston rod 36 moves to the left in the drawing on the energization of the cylinder and piston unit 38, the lever 76 pivots in the counterclockwise direction and the front ends 24a of the separating elements 24 move along the breastbone 8b and under the clavicle 8c.

Claims: Method for automatic removal of at least an inner fillet (70) from slaughtered poultry or a part thereof by scraping off the inner fillet from the slaughtered poultry or part thereof, characterized in that prior to scraping off the inner fillet the membrana sternocoracoclavicularis is released by making a separation in the opening defined by the natural position of the clavicle (8c; 80) and the breastbone (8b). Method according to claim 1, characterized in that , before the inner fillet (70) is scraped off, the connection between the inner fillet membrane and the breastbone (8b) in the region of the coracoideum (8d; 82) is broken. Method according to claim 1 or 2, characterized in that the inner fillet (70) is only partly scraped off, whereupon the part already scraped off is gripped and the inner fillet (70) is pulled free from the poultry substantially in front of the breast thereof. Method according to any of claims 1-3, characterized in that the clavicle (8c; 80) is removed before the filleting. Apparatus for automatic removal of at least an inner fillet (70) from slaughtered poultry or a part (8) thereof, comprising a carrier (6) for fixing thereon the poultry or a part (8) thereof, at least comprising the breast with the inner fillets (70) attached; and scraping means (58) for scraping off the inner fillets (70) from the slaughtered poultry or part thereof, characterized in that the apparatus is provided with separating elements (24) for the inner fillets (70), which elements (24) are adapted to be inserted, on opposite sides of the breastbone (8b), into the openings defined by the natural position of the clavicle (8c; 80) and the breastbone (8b) for the purpose of releasing the membrana sternocoracoclavicularis; Apparatus according to claim 5, characterized by membrane separation means (42, 46) for breaking the connection between the membrane of the inner fillets (70) and the breastbone (8b) in the region of the coracoideum (8d; 82). Apparatus according to claim 5 or 6, characterized by inner fillet removal means for gripping the inner fillet (70) and pulling it free from the poultry substantially in front of the breast thereof. Apparatus according to any of claims 5-7, characterized in that the separating elements for the inner fillets (70) consist of two substantially parallel plates facing one another and having a free end (24a), the plates (24) being mounted resiliently in relation to one another and in relation to a holder (21), said holder (21) being controllably movable relative to the carrier (6). Apparatus according to claim 8, characterized in that the distance between the plates (24) is shorter than the maximum width of the breastbone (8b). Apparatus according to claim 8 or 9, characterized in that the free ends (24a) of the plates (24) are provided with blunt edges. Apparatus according to claim 6, characterized in that the membrane separation means for the inner fillets comprise two rotatable discs (42) extending generally in one and the same plane. Apparatus according to claim 11, characterized in that the circumferential edge of the discs (42) is frustoconical. Apparatus according to claim 11 or 12, characterized in that the circumferential edge of the discs (42) is provided with at least one radially projecting knife (46). Apparatus according to any of claims 5 - 13, characterized in that the scraping means for the inner fillets (70) consist of two scraper plates (58) mounted resiliently at an angle to one another and to a holder (56), the holder (56) being movable in a controllable manner relative to the carrier (6), while the scraper plates (58) are adapted to be placed on opposite sides of the clavicle (8c; 80) and then on the latter and to be moved along the breastbone (8b) away from the clavicle (8c; 80). Apparatus according to claim 14, characterized in that the distance between the scraper plates (58) is shorter than the maximum width of the breastbone (8b). Apparatus according to claim 6, characterized in that the carriers (6) form part of a conveyor (2a, 2b, 3, 4) along whose path the separating elements (24), the membrane separation means (42, 46) and the scraping means (58) are installed.

Inventors: JANSSEN PETRUS CHRISTIANUS HEN, VAN DEN NIEUWELAAR ADRIANUS JO, JANSSEN, PETRUS CHRISTIANUS HENDRIKUS, VAN DEN NIEUWELAAR, ADRIANUS JOSEPHES
Applicants: STORK PMT, STORK PMT B.V.
Application year: 1995
Main classification: A22C21
IPC codes: A22C21