Method and Apparatus for Mechanically Obtaining Meat From Poultry Bodies

1. Field of the Invention

The invention relates to a method for mechanically obtaining meat from the bodies of slaughtered poultry, which bodies are moved past a number of tools, as well as to an apparatus for performing this method with continuously moved conveyors having receptacles for holding the poultry bodies to be processed, as well as tools arranged along the conveyor path for detaching the meat from the skeleton.

2. Prior Art

EP-Al-168 865 discloses an apparatus, which although directed at removing the top part of the wishbone (clavicula), said processing step, however, preceding a filleting process, which results in a double fillet comprising the breast meat in the form of the outer fillets and the inner fillets. In this apparatus the poultry bodies in the form of front halves are saddled onto the saddles of a conveyor driven in rotary manner, so that a horn of the saddle projects into the neck opening and the breast part is directed upwards. The filleting of the poultry body conveyed with the neck opening leading takes place in the lower run of the apparatus and starts with the retaining of the breast meat and thus the stripping thereof from the wish-hone up to the breast-bone (sternum) and is continued by a scraping tool, which is adapted to the poultry body shape and which brings about the separation of the meat up to the breast-bone comb (crista sterni) by penetrating between the skeleton and the meat. Following scraping fingers bring about the detachment from the sides of the breast-bone in its transition region to the breast-bone plate (corpus sterni) and finally the complete separation of the double fillet by means of paring belts driven in rotary manner.

According to a further embodiment of this prior art document a first filleting tool is constituted by a pair of milling or cutting rollers, which raise from the skeleton the fillet meat located in the vicinity of the ribs. This tool is followed by a scraping tool of the type described hereinbefore and which brings about the separation of the meat up to the breast-hone comb. A tool comprising paring belts driven in rotary manner finally carries out the complete separation of the double fillet.

EP-Al-207 553 discloses a further apparatus for obtaining meat from poultry bodies in the form of double fillets. Here again the starting product is the front half of a poultry body, which is inverted or pushed onto the saddle horn of a saddle forming part of a revolving conveyor. During the saddling the wing joints and therefore the attachment points of the wish-bone are kept inwardly displaced and the poultry body is delivered in this way to the filleting tools arranged along the bottom strand of the conveyor and the fillet meat is essentially obtained by sliding off.

The products resulting from these known methods do not meet the requirements regarding their optical impression, which results both from the contour and from the manner in which the separation surface is produced

3. Objects of the Invention

The main object of the invention resides in improving such methods and devices for obtaining fillets from poultry bodies with regard to the above requirements and criteria.

In such improvement, it is a particular object to obtain an optically attractive product.

It is a further essential object to achieve this with maximum fillet meat yield.

These objects are achieved by a method in which the bodies are present in a form freed from their extremities and the skeleton essentially comprises the breast-bone (sternum) constituted by the comb or crest (crista sterni) and the breast-bone plate (corpus sterni), and the wing joints carried by the coracoid bones (coracoidae) with the wish-bone (clavicula), as well as possibly at least parts of the ribs, which bodies are conveyed with the wing joints leading and in their longitudinal direction with an orientation of the part of the breast-bone plate (corpus sterni) facing the body cavity substantially parallel to the conveying direction, by the method steps of

(a) releasing the outer fillets from the coracoid bones and from any ribs, as well as the connections between the outer fillets and the inner fillets, essentially up to the crest (crista sterni) of the breast-bone,

(b) severing the connection between the outer fillets and the wing joints while detaching the outer fillets from the wish-bone,

(c) tearing off the two outer fillets from the crest of the breast-bone in one piece,

(d) tearing the skin surrounding the inner fillets, and

(e) stripping the inner fillets from the skeleton

The product resulting from this method comprises the outer fillets as double fillets and the inner fillets separated therefrom.

If, however, the meat is to be obtained in one piece, i.e. in the form of the outer fillets as a double fillet surrounding the inner fillets adhering thereto, these above objects are achieved by a modified method comprising a modified method step (a), in which the detachment of the meat is related to the outer fillets and the inner fillets; detaching the meat from the sides of the crest of the breast-bone prior to performing method step (b); and then carrying out method step (c), in which the inner fillets are also included.

To achieve the objects set out above, there is also an apparatus comprising a continuously moving conveyor with receptacles for holding the poultry bodies to be processed, as well as tools for releasing the meat from the skeleton arranged along the conveyor path, which apparatus comprises a sequence of severing tools for performing the single method steps subsequently, at least part of which tools is arranged along the lower run of the conveyor. The tools are arranged such that in an early tool station the outer and inner fillets may either be scraped off the skeleton separate from each other to obtain an outer double fillet and two inner fillet pieces or be detached from the skeleton together to result in a one piece double fillet in which the two outer and inner fillets adhere to each other.

The advantages resulting from the invention lie essentially in minimum stressing of the meat, because the individual tools are so constricted in their working area, that they can be readily adapted to the anatomical conditions. This results in reliable, careful working, an attractive product, and high productivity and yield.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which by way of illustration schematically show preferred embodiments of the present invention and the principles thereof and what now are considered to be the best modes contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the scope of the appended claims. In the drawings

FIG. 1 shows a simplified overall view of the apparatus according to the invention in axonometric form;

FIG. 2 represents an apparatus according to FIG. 1 for obtaining a double fillet including the inner fillets;

FIG. 3 is an axonometric view of the skeleton of part of the poultry body termed as the breast cap;

FIGS. 4 to 8 each show axonometric representations of the individual working stages after carrying out method steps (a) to (e) shown in each case as being performed on only one side.

The apparatus according to the invention is installed on a machine frame, of Which, in order not to overburden the drawing, FIG. 1 only shows the part covering the working area. In this area there is a pair of guide profiles 1 sloping towards one another in roof-like manner and having a gap 2 in the vicinity of the ridge line. The profiles 1 extend symmetrically to either side of the path of a conveyor 3. The latter comprises a chain 4 only indicated in its upper strand or run and which is driven continuously in rotary manner in a vertical plane of rotation. The chain 4 is provided with receptacles 5 for holding the poultry bodies 58 (see FIG. 3) to be processed. Each of the receptacles 5 comprises a saddle part 6, which forms with a clamping part 7 a gripper controllable by means of not shown. frame-fixed cam or curved rails. The gripper is brought into a Closed position prior to the entry of the receptacles 5 into the area of the tools by raising the clamping part 7. These tools are arranged in pairs and symmetrically on either side of the path of the conveyor 3.

In this construction, a first tool 8 comprises on either side of the path of the conveyor 3 a lever 10 pivotable about a vertical axis 9 and which at its free end has a scraping tool 11 comprising a scraper 12 in the form of a scraping finger. This finger, in an appropriate, not shown way is mounted so that it can give way upwards against spring tension. A drive provided in the form of a pneumatically driven pivot or swivel cylinder 13 and bringing about the rotation of axis 9 engages the latter. The cylinder 13 is able to elastically pivot the scraper 12 between a position alongside the path of the poultry body 58 and a position crossing the same.

The tool 8 is followed by a second tool 14, which has a guide element 15 on either side of the path of the conveyor 3. The guide elements 15 extend in such a way as to leave a gap 16 narrowing in the conveying direction, rise in closely juxtaposed manner and comprise round bars 17. Each one of the ends 18 thereof directed against the conveying direction is spread outwards, so that each guide element 15 starts above the roof surface of the respective associated guide profile 1. The round bars are designed to extend outwards to form guide surfaces 19 in the vicinity of the gap 16. The guide elements 15 are mounted in such a way that their outward displacement counter to the tension of springs 20 is possible. In the zone of the apparatus comprising the guide elements 15 is also provided a cutting tool 21 with a pair of paring knives 22. Each of the latter is fitted to the free end of a lever 24 and comprises a blade, whose paring edge 23 is oriented substantially perpendicular to the conveying direction and extends in a horizontal plane. Each paring knife 22 is mounted in a vertical axis 25 and can be pivoted in the driving direction of the conveyor 3 against the tension of a spring 26. The other end of the lever 24 is fixed to a vertical axis 27, on which engages a drive in the form of a pneumatically operated pivot or swivel cylinder 28 bringing about the rotation thereof and which is able to elastically pivot the paring knife 22 from a position alongside the path of the poultry body 58 into a position crossing the same. In the pivoted-in position, the paring knives 22 are located directly below the guide surfaces 19 of the guide elements 15.

The tool 14 is followed by a third tool 29 in the form of a retaining device 30 having a pair of clamping elements 31. Each of these is fitted to the free end of a lever 32, whose other end is fitted to a vertical axis 33, on which engages a drive bringing about the rotation thereof and in the form of a pneumatically operated swivel or pivot Cylinder 34. This cylinder is able to pivot the clamping elements 31 from a basic position crossing the path of the poultry bodies 58 to a position alongside said path. The clamping elements 31 have clamping edges 35 which are oriented so as to rise with respect to the path of the poultry bodies 58 and in the conveying direction thereof and form, in the basic position, a clamping gap 36 tapering in V shaped manner in the conveying direction

The retaining device 30 is followed by a fourth tool 37, which comprises a pair of skid- or ski-shaped friction elements 39, which can be moved in controlled manner from above into the path of the poultry bodies 58 by a pneumating drive 38.

Finally, a last and fifth tool 40 comprises a pair of scrapers 41, Whose scraping edges 42 are adapted to the cross-sectional contour of the skeleton of the poultry body 58 in the region of the crest 60 of the breast-bone 59 and the breast-bone 61. These scrapers 41 are mounted to be pivoted in scissor-like manner about axes 43 arranged above the path of the poultry bodies 58 and can be moved into the path of said poultry bodies 58 in a controlled manner with the aid of a pneumatic drive 44. Driving is transferred to the scrapers 41 by means of guide rods 45, which form the connection between a drive yoke 46 and control levers 47 arranged on the scrapers 41.

The described apparatus may be modified in accordance with FIG. 2 for obtaining the outer fillets 66 as a double fillet together with the inner fillets. In this case, the third tool 29 forms the end of the tool series and between it and the second tool 14 is inserted a scraping tool 48, which has a pair of scraping fingers 49, each of which is arranged on the free end of a lever 50 and gives way upwards against a not shown spring. The scraping fingers 49 have ends 51 projecting upwardly in hook-like manner, which ends are secured in inclined manner in the conveying direction. The other end of the lever 50 is fixed to a vertical axis 52, on which engages a drive bringing about the rotation thereof and being designed as a pneumatically operated swivel or pivot cylinder 53, which is able to elastically pivot the scraping fingers 49 between a position alongside the path of the poultry body and a position crossing the same.

The apparatuses operate as follows:

A poultry body 58 prepared in accordance with FIG. 3 and 4, i.e. which has been freed from its extremities and commercially known as a breast cap, immediately upon passing of a receptacle 5 within the loading area of the apparatus according to FIG. 1 is placed on the guide profile 1 with the breast-bone 59 upwards and with the wing joints 63 pointing forwards, so that the outer parts of the inside of the breast-bone plate 61 rest on the roof-shaped support surfaces of the guide profile 1. The breast cap 58 is then moved against the continuously moving receptacle 5, so that the saddle part 6 thereof with its horn-like extension runs between the branches of the wish-bone 64 and onto the part of the breast-bone plate 61 positioned upstream of the crest 60 of the breast-bone 59 whilst engaging over the same. In the meantime the receptacle 5 has approached the working area of the tools for cutting the meat from the skeleton, so that the clamping part 7 of receptacle 5 has been raised by running onto a not shown, frame-fixed curved or cam rail and consequently the breast cap 58 is secured. The breast cap 58 securely held in this way now passes into the area of the first tool 8, whose function is to detach the outer fillets 66 from the coracoid bones 62 and any ribs 65 which may be present, as well as the connection between the outer fillets 66 and the inner fillets 67. This is brought about by controlled movement of the scrapers 12 kept pivoted out of the path of the poultry body 58 by corresponding activation of the pivot cylinders 13, so that the scrapers 12 are introduced into the meat directly behind the wing joints 63 and between the wish-bone 64 and the coracoid bones 62. This process is indicated by the illustration of FIG. 5. The correct time for the controlled movement of the scrapers 12 can be determined by adjusting a not shown switching element, whose operation takes place by the passage of the receptacle 5. The control of the following tools can take place in the same Way. Processed in this way the breast cap 58 passes into the region of the second tool 14, Which initially penetrates with the guide elements 15 or their ends 18 into the joint surface formed and at the same time lifts the outer fillets 66 according to FIG. 6. As a result of the inclination of the guide elements 15 and their oppositely effective elasticity, the outer fillets 66 are drawn upwards under a certain tension, so that their outer faces undergo reciprocal engagement. In this tensioned state the aCtion field of the severing tool 21 is reached, whose paring knives 22 with their sharpened paring edges 23 initially cut through the connection between the outer fillets 66 and the wing joints 63. This separating cut passes into a paring process, in which the outer fillets 66 are stripped from the wish-bone 64 which, during this process and as a result of its inherent tension, is urged against the underside of the baring edges 23. At the instant when the paring knives 22 reach the crest 60 of the breast-bone 59, they are moved under control out of engagement by a corresponding activation of the pivot cylinders 28, so that the outer fillets 66 are now only connected to the skeleton at the sides of the crest 60 of the breast-bone 59. This connection is severed by means of the following retaining device 30, whose clamping elements 31 penetrate into the previously produced severing surface and hold both outer fillets 66 in the wedge-shaped clamping gap 36, so that, whilst exerting a certain scraping effect as conveying advances, they are detached from the sides of the comb 60 of the breast-bone 59 by tearing-off (cf. FIG. 7). As a result there is obtained a double fillet embracing the two outer fillets 66 and which is released prior to the arrival of the next receptacle 5 by briefly opening the retaining device 30 through a corresponding activation of the pivot cylinder 34. The now largely exposed skeleton, which only carries the inner fillets 67, subsequently passes into the action area of the tool 37, whose friction elements 39 engage under slight pressure on the inner fillets 67, as a result of the activation of drive 38. As a result of the relative movement between the friction element 39 and the inner fillet 67, which movement is produced by the conveying, the skin surrounding the fillet is destroyed. so that the subsequent stripping of the inner fillets 67 is facilitated. Stripping takes place with the aid of the tool 40, whose scrapers 41 are moved in controlled manner into the path of the skeleton directly after the passage of the wing joints 63 as a result of a corresponding activation of the drive 44. As shown in FIG. 8, the inner fillets 67 are scraped from the crest 60 and the breast-bone plate 61 by said scrapers 41.

It is possible to obtain the outer fillets 66 and the inner fillets 67 in one piece by converting the apparatus into that of FIG. 2. The scrapers 12 of the first tool 8 are set somewhat lower and the scraping tool 48 is installed following the same. Controlled movement takes place directly after the passage of the wing joints 63, whereby the scraping fingers 49 penetrate the separation surface created by the scrapers 12 of the first tool 8 and detach the inner fillets 67 and also the outer fillets 66 from the flanks of the crest 60 of the breast-bone 59. The tool 14 follows in unchanged arrangement, and following the operation thereof the poultry meat is released in the form of a double outer fillet embracing the inner fillets 67 by means of the also unchanged retaining device 30.

As a result of the arrangement of the processing tools in association with the lower strand of the conveyor 3 the possibility arises of an overhead processing of the poultry bodies which with the cooperation of gravity, can lead to a better collection or lifting of the meat parts detached and the guidance thereof, as well as a simplification of the corresponding elements.