Apparatus for severing the vent of slaughtered poultry

Abstract: An apparatus for severing the vent of slaughtered poultry, comprising positioning and stretching means for the poultry, a centring pin (11) to be inserted into the vent, a clamping sleeve (13) concentrically surrounding the centring pin, and a rotary cutter (14) concentrically surrounding the centring pin and clamping sleeve. A stretching sleeve (7) is provided for engaging around the vent of the poultry, whereas the centring pin and the clamping sleeve have a fixed rotational position.

Description: The invention relates to an apparatus for severing the vent of slaughtered poultry, comprising positioning and stretching means for the poultry, a centring pin having a thickened end portion to be inserted into the vent and being movable in relation to the positioning and stretching means, a clamping sleeve concentrically surrounding and being movable in relation to the centring pin for clamping the orbicular muscle surrounding the vent between same clamping sleeve and the centring pin, and a shell-shaped rotary cutter concentrically surrounding the centring pin and clamping sleeve for severing the vent. With the known apparatuses of this kind (which are usually but not solely equipped to process poultry while the same is suspended from an overhead conveyor) the positioning and stretching means consist substantially of one of a number of stretching brackets that engage the lower body of the poultry between or near the legs. After the poultry has been fixed with the aid of said positioning and stretching means, the centring pin with its thickened end portion is inserted into the vent. With the aid of the rotary cutter the skin is then cut around the vent after which by a relative displacement of the centring pin in relation to the clamping sleeve, the cut vent and the orbicular muscle are clamped between the clamping sleeve and the head of the centring pin, in this manner allowing the vent and the intestines connected thereto to be drawn at least partially from the poultry. Although with this prior art apparatus there is a relative longitudinal displacement of the centring pin in relation to the clamping sleeve and the cutter, these parts of the prior art apparatus nevertheless have a fixed rotational position in relation to one another. This means that the centring pin and the clamping sleeve rotate together with the shell-shaped rotary cutter. Such an apparatus is known from EP-0722666-A. An apparatus in which a centering pin and the cutter more independently from each other is known from DE- 8625835.4-U. This known apparatus has several disadvantages. Practice has shown that the positioning and stretching means used can not always optimally guarantee that the skin surrounding the vent is pulled sufficiently tight. Consequently, it is not always possible to obtain an optimal cut (i.e. a small round hole around the orbicular muscle). In some cases it is therefore necessary for the cutter to be inserted deeper into the slaughtered poultry, involving the risk of undesirable intestinal damage (whereby the intestinal contents render the meat unsuitable for consumption due to contamination). Similarly it may be necessary, if the cut made by the cutter is not complete to partially tear the vent from the remaining part of the poultry, involving the risk of the intestines tearing. Another disadvantage of the apparatus known from EP-722666-A arises from the fact that the centring pin and clamping sleeve rotate together with the cutter. This causes the intestine to become twisted with the possibility of the intestine tearing. It is the object of the invention to provide an apparatus of the present type with which the above - mentioned disadvantages are eliminated in a simple yet effective manner. To this end the apparatus according to the invention is characterized in that the positioning and stretching means comprise a stretching sleeve that engages around the vent of the poultry and that is positioned such that the centring pin, the clamping sleeve and the cutter can move concentrically through the same, and that the centring pin and the clamping sleeve have a fixed rotational position. It has been shown that with the aid of such a stretching sleeve the skin surrounding the vent can be stretched optimally while at the same time preventing the skin from rotating with the cutter. In this way the shell-shaped cutter can make a perfect cut without the cut having to be inserted deeply into the poultry. This effectively prevents damage to the intestines. The fact that the centring pin and the clamping sleeve no longer rotate with the shell-shaped cutter but remain in a fixed position, also plays a role. Only the mutual longitudinal movement between the centring pin on the one hand and the clamping sleeve and the shell-shaped cutter on the other hand is possible. By choosing a suitable shape for the stretching sleeve, it is possible to ensure that the same will make optimal contact with poultry having a very slack abdominal skin. Practice has shown, that this makes the apparatus suitable for the best possible manner of processing poultry whose live weight comes within a greater range, for example, when the apparatus is set at 1500 to 2500 grams as opposed to 1800 to 2200 grams in the case of the known apparatus of this type. In a preferred embodiment of the apparatus according to the invention the cutter has a smooth cutting edge and a high rotational speed. In the prior art apparatus the cutter has a low rotational speed (for example, 150 revolutions per minute) and the cutting edge is serrated. The combination of a low rotational speed and a serrated cutting-edge results in tearing the vent, ensuing in an irregular cut and possible intestinal damage. However, providing the cutter with a smooth edge and rotating it at high speed, results in a smooth cutting edge and minimizes the risk of intestinal damage. The prior art apparatus was not capable of a high rotational speed because the centring pin and the clamping sleeve rotated together with the shell-shaped cutter, and because a high rotational speed would result in unacceptable twisting of the intestine. However, as in accordance with the invention the centring pin and the clamping sleeve do not rotate, the cutter may have a high rotational speed without thereby causing the intestine to become twisted. Within this framework it is preferred for the cutter to make at least 1000 revolutions per minute. As already briefly mentioned in the above, the shape of the stretching sleeve is designed such as to allow optimal operation. For example, in a special variant of the apparatus according to the invention, the stretching sleeve is at the side that during use faces the tailbones of the poultry, preferably provided with a bevel. This ensures that this side also is properly in contact with the poultry. The invention will now be elucidated with reference to the drawings in which: Figure 1, shows partly in a side view and partly in cross section a portion of an embodiment of the apparatus according to the invention; Figure 2, shows in a side view the lower portion of the apparatus depicted in Figure 1; Figure 3, shows a top view of the portion shown in Figure 2; Figure 4, shows substantially in cross section the upper portion of the apparatus depicted in Figure 1; Figure 5 shows the apparatus in six successive operational phases; and Figures 6 to 11, show on a larger scale the phases depicted in Figure 5. Figure 1, shows a portion of the embodiment of the apparatus according to the invention in a side view and partially in cross section. In this case the apparatus interacts with a conventional overhead conveyor with carrying hooks 1 from which the slaughtered poultry is suspended by the legs. Such an overhead conveyor is known in itself and does not require any further explanation. As is usual with apparatuses for the processing of slaughtered poultry, this concerns a turret-like apparatus with, distributed over its circumference, a number of processing stations, only one of which is represented in Figure 1. Such a turret-like apparatus comprises curved tracks 2 able to interact with tracking runners 3 to effect various movements of parts of the apparatus. For this purpose search parts may be slidable along guides 4 or the like. The interaction between such curved tracks 2 and tracking runners 3 is known with turret-like apparatuses of this kind, and does not require any further explanation. A lower portion of the apparatus for the removal of the vent of slaughtered poultry is provided with positioning and stretching means for the poultry. This includes brackets 5 engaging the legs and a U-shaped bracket 6 engaging the lower body of the poultry. The dimensions and geometry of said brackets 5 and 6 are adapted to the body geometry of the poultry to be processed. The suspended position in which the poultry is supplied by the carrier hook 1, is also taken into consideration. As will be seen later, the U-shaped bracket 6 occupies a permanent position, whereas the brackets 5 move up and down along the lower guide 4 as a result of the interaction between the respective tracking runner 3 and curved track 2. The positioning and stretching means further include a stretching sleeve 7 that can be clearly seen in Figure 2 and Figure 3. This stretching sleeve is attached to the U-shaped bracket 6 in such a manner that in an operational position, the same will engage the lower body of the poultry around the vent. The skin surrounding the vent will thus become stretched tight. The stretching sleeve 7 possesses a through-opening 8, through which parts of the apparatus can extend, as will be described later. A side of the stretching sleeve 7 that during operation of the apparatus faces toward the tail bone of the poultry to be processed, is provided with a bevel 9. In this way the stretching sleeve 7 is optimally adjusted to the local body geometry of the poultry to be processed. The positioning and stretching means may further include a support plate 10, which serves to support the back of the poultry to be processed. With reference to Figure 1, but in particular also to the enlarged representation in accordance to Figure 4, the apparatus is also provided with an upper portion comprising, among other things, a centring pin 11 having a thickened end portion 12 that can be moved up and down in the vertical direction, a clamping sleeve 13 concentrically surrounding the centring pin, as well as a shell-shaped cutter 14 concentrically surrounding both the centring pin 11 and the clamping sleeve 13. The movements effected by the interaction between the tracking runners 3 and curved tracks 2 are such that the centring pin 11 with the thickened end 12 can move longitudinally in relation to the clamping sleeve 13 and the shell-shaped cutter 14. In the same longitudinal direction, the clamping sleeve 13 and the shell-shaped cutter 14 are in a fixed position in relation to one another. According to common usage, the shell-shaped cutter 14 is rotatingly driven by means that are not explained in detail. As will be explained later, this makes it possible for the shell-shaped cutter to sever the vent of the slaughtered poultry. In the apparatus according to the invention the sequence is chosen such that the centring pin 11 and the clamping sleeve 13 do not rotate, thus have a fixed rotational position. When the apparatus is in use, only the shell-shaped cutter 14 will rotate. The external diameter of the shell-shaped cutter 14 is such as to allow it to project through the opening 8 of the stretching sleeve 7 of the lower portion of the apparatus. The working of the apparatus will now be explained in more detail with reference to the Figures 5 to 11. It should be noted, that Figure 5a corresponds with Figure 6, Figure 5b with Figure 7, Figure 5c with Figure 8, Figure 5d with Figure 9, Figure 5e with Figure 10, and Figure 5f with Figure 11. The poultry is not shown in Figure 5. Figure 5a (and Figure 6) shows the position in which the poultry 15 is not yet stretched by the brackets 5 and 6. The centring pin 11, the thickened end portion 12, clamping sleeve 13 and shell-shaped cutter 14 are still at some distance above the stretching sleeve 7. Figure 5b (and Figure 7) shows the position in which the poultry 15 to be processed and that is suspended by its legs 16 in the carrier hooks 1 of the overhead conveyor, is positioned with its lower body against the U-shaped bracket 6. For this purpose the brackets 5 are moved upwards. The stretching sleeve 7 is positioned around the vent 17 such that the skin surrounding said vent 17 is stretched tight and the vent is lifted upward. The bevel 9 of the stretching sleeve 7 matches the natural geometry of the poultry, namely the tailbones 18. The brackets 5 engage the legs 16. The centring pin 11 having a thickened end portion 12, the clamping sleeve 13, and the shell-shaped cutter 14, are still positioned at some distance above the stretching sleeve 7. Figure 5c (and Figure 8) shows the operational condition of the apparatus, in which the centring pin 11, with the thickened end portion 12, is inserted into the vent of the poultry. The shell-shaped cutter 14 is about to engage the skin surrounding the vent. The orbicular muscle 18 of the vent is clearly visible. In this situation the shell-shaped cutter 14, and the centring pin 11 (and to a lesser extent the clamping sleeve 13) extend through the opening 8 of the clamping sleeve 7. Under the influence of the previously-mentioned interaction between the various tracking runners 3 and curved tracks 2, the rotatingly driven shell-shaped cutter 14 then moves (in a manner not shown) further downward, severing the vent around the orbicular muscle 18. As mentioned earlier, the shell-shaped cutter 14 and the clamping sleeve 13 occupy a mutual permanent longitudinal position. This means, that when moving the shell-shaped cutter 14 downward, the clamping sleeve 13 is moved downward also. By simultaneously making an upward movement with the centring pin 11 and its thickened end portion 12, the situation shown in Figure 9 (and Figure 5d) is reached, wherein the circumference of the thickened end portion 12 of the centring pin 11 cooperates with the internal circumference of the clamping sleeve 13 to thereby enclose the orbicular muscle 18. While severing the vent, the shell-shaped cutter 14 rotates at high speed, for example, 2000 rotations per minute. However, the centring pin 11 and the clamping sleeve 13 do not rotate. This prevents the vent from rotating and the intestines 19 connected to the vent from twisting and possibly tearing. After the vent has been severed in the manner shown in Figure 9 (and thus also in Figure 5d) and the orbicular muscle 18 has been enclosed, the assembly comprising centring pin 11, clamping sleeve 13, and shell-shaped cutter 14, is moved upwards out of the clamping sleeve 7 into the position shown in Figure 5e and Figure 10. The orbicular muscle 18 remains enclosed between the thickened end portion 12 of the centring pin 11 and the clamping sleeve 13. The intestine 19 is thereby partially extracted from the abdominal cavity of the poultry. As is apparent also, the bracket 5 may already be moved downward during this phase. Basically, the removal of the vent of the poultry is now completed. Optionally, as shown in Figure 5f and Figure 11, the centring pin 11 may be partially moved downwards again (or the clamping sleeve 13 may be moved upwards), releasing the orbicular muscle 18, and allowing it to slide down over the thickened end portion 12 of the centring pin 11. In this way the intestine is placed over the back of the poultry. In the embodiment shown, the shell-shaped cutter 14 used in the apparatus according to the present invention has a smooth cutting edge. It is possible to use such a smooth cutting edge because the shell-shaped cutter 14 is capable of a high rotational speed. Since the centring pin 11 and the clamping sleeve 13 do not rotate, there is no fear of the intestine 19 becoming twisted (with the risk of tearing) due to the rotation of the shell-shaped cutter 14. In the conventional apparatus the centring pin and the clamping sleeve rotate together with the shell-shaped cutter, making it necessary to operate at a low rotational speed in order to reduce the twisting effect. This generally means that the cutter has to be serrated in order for it to be able to cut adequately. However, this serration entails the risk of undesirable intestinal damage. With the aid of the stretching sleeve 7, the skin surrounding the vent is stretched, always allowing the performance of an optimal cut. This means that the shell-shaped cutter 14 does not need to be inserted into the abdominal cavity of the poultry deeper than necessary, which further reduces the risk of intestinal damage. Also, this method permits the best possible processing of poultry with slack abdominal skin. The invention is not limited to the above embodiment which, within the framework of the invention specified by the appended claims, may be varied in numerous ways.

Claims: An apparatus for severing the vent of slaughtered poultry, comprising positioning and stretching means for the poultry (5, 6, 7, 10), a centring pin (11) having a thickened end portion (12) to be inserted into the vent and being movable in relation to the positioning and stretching means, a clamping sleeve (13) concentrically surrounding and being movable in relation to the centring pin (11) for clamping the orbicular muscle surrounding the vent between same clamping sleeve (13) and the centring pin (11), and a shell-shaped rotary cutter (14) concentrically surrounding the centring pin (11) and clamping sleeve (13), for severing the vent, characterized in that the positioning and stretching means comprise a stretching sleeve (7) engageable around the vent of the poultry and that is positioned such that the centring pin (11), the clamping sleeve (13) and the cutter (14) can move concentrically, through the same, and in that the centring pin (11) and the clamping sleeve (13) have a fixed rotational position. An apparatus according to claim 1, characterized in that the cutter (14) has a smooth cutting edge and a high rotational speed. An apparatus according to claim 2, characterized in that the cutter (14) makes at least 1000 revolutions per minute. An apparatus according to one of the preceeding claims characterized in that at the side that during use faces the tailbones of the poultry, the stretching sleeve (7) is provided with a bevel.

Inventors: DE HEER CEES, JANSEN TOM CORNELIS, DE HEER, CEES, JANSEN, TOM CORNELIS
Applicants: MEYN FOOD PROC TECHNOLOGY BV, MEYN FOOD PROCESSING TECHNOLOGY B.V.
Application year: 2000
Main classification: A22C21
IPC codes: A22C21