Process for filleting of meat

Abstract: Process for filleting bone-containing meat material, where the bone knuckle is secured during the removal of meat from the bone with a knife assembly and where the meat is removed by its being drawn/pushed from the bone in an approximately linear movement by means of non-rotating scraping knives. A device for performing the process is also disclosed.

Description: The present invention concerns a process for filleting meat material containing bones, especially from live-stock, such as poultry and pigs, where the filleted meat is kept mainly intact. There are previously known mechanised methods for filleting of meat from bone-containing material. Such devices, however, suffer from several weaknesses both in construction and embodiments. The general problem with filleting of bone-containing meat material where the bone consists of a central bone which runs through the piece of meat, for instance a thigh-bone from chicken, lies in the shape of the bone. Generally, such a bone consist of a more or less straight bone pipe with an expansion (knuckle/club) on each end. These knuckles form an obstacle to mechanically pressing off the meat from the bone, both as they are physically working as a stopper for the meat during the pressing off and in addition because knives which are used by the mechanical filleting have a tendency to dull when they cut into the bone material. There is thus known in the art a machine from Protecon systems (Protecon Automatic Deboning systems for Poultry, P.A.D.) for automatic filleting of thigh bones and wings from poultry. This system comprises inter alia a transport band with upwards extending pins for introduction of the meat pieces in the filleting machine. However, such an embodiment of the transport band will, when used, cause the meat material to stick between the pins and the transport band and prevent further operation of the machine until it has been cleaned. This will lead to a stop in the operation and wasted working time. A further drawback of such a machine is that possible broken bones in the material are not considered. In industrially handled material, there may be as much as up to 30-40 % broken bones and this results in the finished filleted material from the filleting machine containing unacceptably large amounts of bone material. Also the forms of the transport band represent a drawback by the mentioned type of machine. These forms have no possibility for regulation, so that small meat pieces will have a poor fastening and may thus be led the wrong way into the machine, while large meat pieces will lead to the previously mentioned clogging of the pins on the transport band with the disadvantages this leads to. Another known type of filleting machine is sold by Barker/FoodCraft and uses, for the removal of the meat from the bone of meat material, knives rotating about the longitudinal axis of the bone. This machine does not consider bones broken before treatment of the piece of meat for filleting either, even though the distributor maintains that breaks caused by the use of the machine are reduced. One disadvantage of this type of machine is that the meat has a tendency to be ground into minced meat by the rotating knives, so that the production of whole fillets of meat is difficult to achieve. A third type of filleting machine is known from European Patent Application No. PCT/AU84/00246 with international publication No. WO 85/02320. This type of filleting device however, uses another principle than the present invention, since this known device uses water under high pressure to remove the meat from the bone of the treated meat pieces. Such an embodiment has, however, the disadvantages that the meat easily may become insipid and that the piece of bone must be secured very firmly since the piece of meat rotates at high speed during the filleting process to remove the loosened meat with the aid of the centrifugal force, and will thus comprise a cumbersome process for this type of filleting. It is an object of the present invention to provide a process for filleting meat from bone-containing meat material where the whole meat fillets are kept mainly without being destroyed, where the degree of utilization of the meat pieces is high and the process is simple to perform. The distinguishing feature of such a process is that one of the knuckles of the central piece of bone which passes through the meat material is removed before the meat is pressed off the bone by means of a knife device which will be described later. In order that the present invention may be more readily understood the following description is given of a device for carrying out the above process. Such a device will be described below with reference to the enclosed drawings, where: FIGURE 1 shows an embodiment of the device for carrying out the method of the invention; FIGURE 2 shows a partial view of the knife assembly in the device of Figure 1; FIGURE 3 shows an extreme position of the knife assembly of Figure 2; FIGURE 4 shows an embodiment of a holder in the device of Figure 1; and FIGURE 5 shows an other embodiment of a holder in the device of Figure 1, shaped as a knife assembly. When using the device shown in Figure 1, it is necessary to use pieces of meat where there is only one knuckle. Such pieces of meat may be produced either by previously removing one of the knuckles of the piece of meat or by dividing a piece of meat with bone into two, so that each part retains one knuckle. For removal of the meat from the bone in the treated piece of meat, the knuckle is placed in the slot (a) in the holder (1). The rest of the disclosed treatment steps are automatic and preferably pneumatically or hydraulically controlled. To secure the piece of meat, there is a securing device (Figures 1-3) shown as a piston (2) which is pneumatically or hydraulically controlled, to press the knuckle securely in the slot (a) in the exchangeable holder (1). After clamping of the knuckle of the piece of meat, the components of the apparatus are in the positions depicted in Figures 1 and 2. The clamping area is at the forward end of the enclosure of the apparatus, which includes the vertically (as oriented in the drawings) movable piston (2) which coacts with the holder (1) to restrain or clamp the knuckle of the meat piece to be processed. Within this area, there is located a knife assembly (3), which includes first and second pairs of knife members, designated (4, 4') and (5, 5'). These knife members are mounted on a pair of side arms (6) which form a frame movable without rotation from the position shown in Figure 2 to the position shown in Figure 3. The lower and upper knife members (4, 4', 5, 5'), respectively, are blade-shaped members oriented for actuation toward one another in a slightly overlapping relation. The arms (6) are pneumatically or hydraulically controlled, and, as will be described, move in two directions. In one movement, the arms (6) move towards one another under force of a piston (9), and in another movement, they move together in a generally horizontal direction, which direction coincides with the orientation of the central section of bone of the piece of meat to be processed as will be described. In the initial position, with the meat piece clamped by the knuckle of the bone, the arms (6) of the frame are retracted to the position shown in Figures 1 and 2. The four knives of the knife assembly (3) are initially out of engagement with the piece of meat. Each of the lowermost pair of knives (4, 4') is fixedly secured to the free end of one of the arms (6), while each of the uppermost pair of knives (5, 5') is pivotable relative to the lower knives (4, 4') and rotatably loaded by means of springs (7), so that the knives adapt themselves automatically to the shape and size of the bone which is to be filleted. In addition, the shape of the knives is such that in the operative pressed together condition (see Figure 3) they define between themselves an opening (10) which approximates to the cross-section of the central section of the bone. With the spring-loaded upper knives (5, 5') irregularities in the contour of the bone are accommodated during scraping or removal of the meat therefrom. The next step in the filleting process is to press together the two knife assemblies which are pneumatically or hydraulically controlled. During this movement, the spaced coacting pairs of knives (4, 4') and (5, 5') traverse a first line toward the piece of meat to cut the tendons, ligaments and meat in the area adjacent the secured knuckle, and to stop at the central bone section. The pressure of the arms (6) may be regulated, for instance by control of the piston (9) which is mounted between the two arms (6). Thereafter, under pneumatic or hydraulic control, the two arms (6) along with the two pairs of knife members (4, 4') and 5, 5'), are extended to move, as a unit, forwards relative to the holder (1) along a second line in a direction outwardly of the machine to the position shown in Figure 3. The meat will thereby be removed from the central bone section and the mainly intact fillets will fall down on a separating chute (8), while the meat-free knuckle will fall down on the other side of the separating chute (8) when the piston (2) again moves upwards to release the knuckle and to receive another piece of meat. In an alternative embodiment the holder (1) may itself comprise an approximately V-shaped knife. By placing the knuckle in such a holder a large part of the tendons and ligaments near the knuckle will be cut when the piston (2) presses the knuckle to secure it in the V-formed knife (see Figure 5). The holder (1) may in addition comprise grooves (b) for the correct positioning in the device according to the invention. The process according to the invention may also be used for meat which has been pre-treated to loosen the bone from the meat, for instance by ultra-sound treatment or by treatment with ligament-attacking enzymes etc. By using the above described process according to the present invention, the loss of meat material upon filleting will be reduced considerably, compared to previous techniques, and at the same time bone splinters will to a larger extent than previously be avoided in the filleted meat material. The present invention at the same time makes it possible to achieve better meat quality, because the meat fillets after treatment by the process according to the invention will be present mainly as undamaged meat. In addition, it will be of advantage to be able to use, to a greater extent than previously, meat pieces with fracture damage in the central bone, whereby such pieces of meat may according to the present invention be cut into two pieces in the fracture before the filleting process begins. Thus, fractured bones will be of no consequence, and at the same time the extent of use of the pieces of meat will be significantly improved.

Claims: A process for filleting meat material from a knuckle bone by securing one end knuckle of the knuckle bone in a holder in a meat filleting device and removing the meat material from the knuckle bone of such bone-containing meat material by means of a knife assembly, characterised by cutting the knuckle bone in said bone-containing material, thereby removing the other end knuckle, and scraping the meat material off the remainder of said knuckle bone by engaging the meat material with the knife assembly and moving said knife assembly linearly relative to and along the shaft of said remainder of said knuckle bone. A process according to claim 1, characterised in that removal of said other end knuckle is effected by cutting said knuckle bone at such a distance from said other end knuckle that the main part of the tendons and cartilage is removed with said other end knuckle. A process according to claim 1 or 2, characterised in that at least a part of the tendons on said one end knuckle is cut when the one end knuckle of the remainder of the bone is placed in said holder. A process according to claim 1 or 3, characterised in that, in the removal of said other end knuckle from the bone, the piece of meat and enclosed knuckle bone are initially cut in two, so that the central bone is cut into two pieces each having its end knuckle intact, whereupon both pieces are separately filleted by means of the set of knives.

Inventors: MIELNIK JAN, MIELNIK, JAN
Applicants: NORSK NAERINGSMIDDELFORSKNING, MATFORSK NORSK INSTITUTT FOR NAERINGSMIDDELFORSKNING
Application year: 1987
Main classification: A22C17
IPC codes: A22C17