WO1992006597A1

WO1992006597A1 - Vent cutter

Info

Publication number: WO1992006597A1
Application number: PCT/NL1991/000204
Authority: WO
Inventors: Cornelis Dirk Harskamp; Petrus Christianus Marius Janssen; Adrianus Josephes Van Den Nieuwelaar
Original assignee: Stork Pmt B.V.
Priority date: 1990-10-16
Filing date: 1991-10-15
Publication date: 1992-04-30
Also published as: AU8859891A; NL9002712A

Abstract

A device for cutting out the vent of a slaughtered animal comprises: a centring element (2, 4); a rotary cutter (16) which can be moved coaxially relative to the centring element; and retaining means for fixing the vent. The retaining means are movable coaxially relative to the cutter and comprise a number of axially directed projections (12) of which ends can project into or through the vent for fixing of the vent. Stripping means (6) are provided for exerting a stripping force on a vent impaled on the projections of the retaining means, in the direction of the ends of the projections for stripping of the vent from them. The stripping means may be fitted in an axially fixed position relative to the centring element, and generally comprise a radial collar of which the shape of at least one external or internal edge is at least partially complementary to that of the cross-section of the projections of the retaining means.

Description

Vent cutter.

The invention relates to a device for cutting out the vent of a slaughtered animal, in particular a bird, comprising: a centring element; a rotary cylindrical surface shaped cutter which can be moved coaxially relative to the centring element, and the inside diameter of which is greater than the outside diameter of the centring element; and retaining means for fixing the vent.

Such a device for cutting out the vent of a bird is known, for example, from the Netherlands Patent Specification No. 156,025. In the use of this device, which can be included in an automated slaughter line, a centring pin is inserted into the vent of a bird, following which the vent is clamped between an end face of a retaining means in the form of a sleeve and a rear face of a thickened centring pin end. The clamping parts are then withdrawn over a short distance, for tensioning the skin around the vent to some extent, in order to facilitate making an incision therein. The cylindrical surface shaped cutter is then moved rotating over the centring pin end, thereby producing a circular incision centred around the vent. The cutter is subsequently withdrawn, followed by pulling of the centring pin and the sleeve with the vent clamped between them out of the bird. The object of this is to remove the rectum in a controlled manner from the bird, so that the risk of bacteriological contamination of the meat of the bird through residues of faeces is minimal.

A disadvantage of the known device is the unreliability of the clamping of the vent between the end face of the sleeve and the rear face of the thickened centring pin end. The two clamping faces of the device are worked smooth in order to permit easy removal of clinging dirt, which, indeed, does improve the hygienic conditions during the cutting of the vent, but provides little grip on the vent. Another factor is that the vent itself is smooth and moist as a result of earlier operations which have been carried out on the bird. These two effects together mean that the vent can slip unintentionally out of the clamping, even if there is a considerable clamping force between the sleeve and the centring pin end. If this occurs during cutting with the cutter, the vent can be carried along by the cutter, so that the chance of damage to the rectum is great and faeces can end up on the bird. This leads to a bacteriological contamination of the meat, which is very undesirable. If the clamping is lost at the moment when the centring pin is pulled out of the bird, the rectum is not pulled far enough or is not pulled at all out of the carcass, which gives rise to problems during further processing of the bird.

The object of the invention is to provide a device for cutting out the vent of a slaughtered bird, in which the vent is fixed securely by retaining means during and after the cutting out. This object is achieved according to the invention by a vent cutter which is characterised in that the retaining means are movable coaxially relative to the cutter and comprise a number of axially directed projections whose ends can project into or through the vent for fixing of the vent, while provision is also made for stripping means for exerting a stripping force on a vent impaled on the projections of the retaining means, in the direction of the ends of the projections for stripping of the vent from them. The use of projections which are inserted in or through the vent (or, more accurately, in or through the skin around the vent or the orbicular muscle in that area) produces a very reliable fixing of the vent, without clamping of the vent being necessary. The vent is in this way secured against rotation along with the cutter, while tensioning of the skin prior to the incision is not necessary. In order to prevent the vent impaled on the projections from sticking on the projections after the cutting-out operation, provision is made for stripping means. This partial feature also greatly benefits the operating reliability of the device.

The stripping means are preferably fitted in an axially fixed position relative to the centring element, for example by fixing the stripping means on the centring element.

In a preferred embodiment the stripping means are designed for the production of a fluid (liquid and/or gas) flow to be directed along the projections in the direction of the ends thereof or at an acute angle with the projections. This means that not only can the envisaged stripping force be exerted, but a cleansing of the projections of the retaining means is also achieved.

The stripping means preferably comprise a radial collar of which the shape of at least one external or internal edge is at least partially complementary to that of the cross-section of the projections of the retaining means, which ensures a good stripping effect in a simple manner.

An essentially disc-shaped or annular design of the stripping means is particularly simple and advantageous.

In another embodiment the stripping means comprise a number of radial projections of which the radius of the circumscribed circle is at least as great as the radius of the inscribed circle of the axial projections of the retaining means.

In an advantageous embodiment of the vent cutter according to the invention, the cutter is provided along the inner periphery thereof behind the cutting edge with an essentially annular thickened part which can interact with the centring element for supporting the vent during a movement of the centring element away from the slaughtered animal with the cut-out vent fixed thereon by means of the retaining means. Providing the cutter with the above-mentioned thickened part ensures that the pierced vent can be sup¬ ported all around during the pulling out of the rectum, which prevents tearing of the vent around the projections. This is achieved in particular through the fact that the difference between the inner radius of the thickened part and the largest outer radius of the centring element is smaller than the thickness of the orbicular muscle. This makes it impossible for the vent to fall off due to tearing around the projections of the centring pin end, because the orbicular muscle cannot pass the opening between the thickened part and the centring element.

For optimum piercing of the vent the point of the projections is situated on the radial outside of the retaining means. This can be achieved, for example, by grinding the point along a plane running at an acute angle to the axial direction of the projection in question. Piercing too close to the vent opening and the consequent tearing of the vent are avoided in this way. An excellent fixing of the vent is achieved if the ends of the projections of the retaining means while projecting into or through the vent can interact with the centring element for fixing of the vent. In a preferred embodiment of this device the rear face of a widened end of the centring element to be inserted into the vent is provided with one or more recesses for the accommodation of the projections provided with a pointed end, as a result of which the projections can project with certainty into or through the vent in all circumstances.

The rear face of the widened centring element end is preferably provided with holes and fixed in a tangen¬ tial direction relative to the projections. Fixing the projections in a tangential direction relative to the holes ensures the projections being in line with the holes.

The idea of the invention includes the advan¬ tageous design possibility that the retaining means are formed by a widened end of the centring element to be inserted into the vent, on the rear face of which element the projections provided with a pointed end are fitted.

The invention and further advantages thereof are explained with reference to the drawing, in which: Fig. 1 shows a partial cross-section of an embodiment of a vent cutter according to the invention and a vent;

Figs. 2 - 6 show successive stages of a vent cutting operation with the vent cutter of Fig. 1; Figs. 7 - 9 show successive stages, corresponding to those shown in Figs. 3 - 5, of a vent cutting operation with the vent cutter according to Fig. 1, which is provided with a cutter in a different embodiment;

Fig. 10 shows a top view of the cross-section X of a part of the vent cutter according to Fig. 1;

Figs. 11 - 13 show variants of the stripping means according to Fig. 10;

Fig. 14 shows a partial cross-section of a variant of the vent cutter according to Fig. 1, provided with different stripping means; Fig. 15 shows a bottom view of the cross-section XV of a part of the vent cutter according to Fig. 14;

Fig. 16 shows a variant of the stripping means according to Fig. 15; Fig. 17 shows a variant of the vent cutter according to Fig. 1, with a slidable stripping collar;

Fig. 18 shows a variant of the vent cutter according to Fig. 1, with stripping means containing a gas or liquid flow; Figs. 19 and 20 show successive stages, cor¬ responding to those which are shown in Figs. 2 and 3, of a vent cutting operation with a vent cutter according to the invention in another embodiment; and

Figs. 21 and 22 show successive stages, cor- responding to those which are shown in Figs. 2 and 3, of a vent cutting operation with a vent cutter according to the invention in a modified embodiment.

Fig. 1 shows a cylindrical centring pin 2 which is provided with an essentially conical thickened centring pin end 4 with a rear face 5. A collar 6 is fixed round the centring pin 2 at a distance from the centring pin end 4. Both the centring pin end 4 and the collar 6 are provided with a number of - in this case four - holes 8 and 10, respectively distributed at regular intervals along the periphery in the direction of the axis of the centring pin 2, the holes 8 in the centring pin end lying in line with the collar holes 10. The holes 8 and 10 are intended to allow through an equal amount of pins 12 which are mounted in a collar end of a round sleeve 14 which is movable only in the axial direction about the centring pin 2. The pins 12 are provided with a pointed end, the point being situated on the radial outside of the retaining element 14, in order to prevent tearing of ^"the vent at the pins 12. Fitted coaxially with the centring pin 2 and the sleeve 14 is a cylindrical surface shaped cutter 16, whose cutting edge 18 is directed towards the centring pin end 4. The cutter 16 is both rotatable and movable in the axial direction relative to the centring pin 2 and the sleeve 14. The combination of centring pin 2, sleeve 14 and cutter 16 can be moved by means of electrical, pneumatic or similar drive means which are not shown in any further detail but are known per se, under the control of suitable control devices which are known per se, and which are not shown in any further detail either. The elements shown in Fig. 1 can form part of a vent cutting device which is included in an automated slaughter line.

In Fig. 1 a cross-section of the vent of a slaughtered animal, e.g. a bird, is shown schematically below the centring pin end 4. Under the skin 20 is the end of the rectum 22, which ends with an orbicular muscle 24 which shuts off the vent opening.

The vent cutting operation is described further with reference to Figs. 1 - 6. Fig. 1 shows the starting position of the vent cutter: the pins 12 are behind the collar 6, as is the cutting edge 18 of the cutter 16. The centring pin 2 and the sleeve 14 are then moved together in the direction of and into the vent, following which a position shown in Fig. 2 is reached. The orbicular muscle is stretched in the process, so that it passes round the centring pin end 4. The sleeve 14 is then moved in the direction of the collar 6, as a result of which the pins 12 successively move through the holes 10, pierce the vent at the orbicular muscle 24 and project into the holes 8 in the rear face 5 of the centring pin end 4. The collar 6 can serve as a stop here for the collar end of the sleeve 14. The position reached is shown in Fig. 3. The next step is to cut out the vent by moving the cutting edge 18 of the cylindrical cutter 16 so far in the direction of the centring pin end 4 that the skin around the vent is cut into far enough, as is shown in Fig. 4. For this purpose, the cutter 16 is set in rotation, as symbolised by the double arrow 17. The cutter 16, the sleeve 14 and the centring pin 2 are then all moved away from the slaughtered animal, while the collar end of the sleeve 14 remains resting on the collar 6 and the vent thus remains fixed around the centring pin end 4. The rectum 22 is consequently drawn a predetermined distance out of the slaughtered animal. This stage, which is shown in Fig. 5, is finally followed by moving the sleeve 14 away from the collar 6. The pins 12 with the vent impaled thereon consequently move in the direction of the collar 6. The complementary shape of the pins 12 and the holes 10 as regards cross-section ensures that the pins 12 can pass the collar 6, but that the vent is stripped off the pins 12 against the collar 6. The vent then comes to rest around the centring pin end 4, following which a relatively small pulling force in the rectum, such as that which occurs, for example, during removal of the the slaughtered animal from the vent cutter, is sufficient to make the rectum pulled out of the slaughtered animal slide off the centring pin end. This situation is shown in Fig. 6, the vent cutting operation then being at an end. Figs. 7 , 8 and 9 again show the respective stages of Figs. 3, 4 and 5 with another advantageous embodiment of the cutter 16. An annular thickened part 30 is provided on the inside of the cutter 16 behind the cutting edge 18. Fig. 7 shows the situation in which the vent is fixed by means of the pins 12 on the centring pin end 4. After this, the cutter 16 is moved rotating to the vent for cutting out the vent. In the stage shown in Fig. 8 the rotation of the cutter 16 is then stopped and the relative axial positions of the centring pin 2, the retaining element 14 and the cutter 16 are fixed. These fixed relative positions are maintained during the withdrawal of the three above-mentioned elements. The withdrawn position is shown in Fig. 9. It can be seen here that the thickened part 30 supports the vent in the radial direction, as a result of which tearing of the vent at the pins 12 as a result of the pulling forces in the rectum is prevented. The annular opening between the thickened part 30 and the thickened centring pin end 4 is so narrow that the orbicular muscle 24 cannot pass said opening.

Fig. 10 shows the collar 6 which is fixed on the centring pin 2 and which is provided along the edge with four holes 10 for allowing through four pins 12. In the variant shown in Fig. 11 the holes 10 of Fig. 10 have been replaced by recesses 10a in the outside edge of a collar 6a which has a diameter which is smaller than the diameter of the circumscribed circle of the pins 12. The diameter of the collar may, if desired, be reduced even further until it is smaller than the diameter of the inscribed circle of the pins 12. This embodiment is shown in Fig. 12, in which no recesses for the pins 12 are necessary any more on the outside edge of the collar 6b. In a next variant of the stripping means according to the invention they comprise radially directed projections 6c fixed on the centring pin, as is shown in Fig. 13.

Figs. 14 and 15 show the vent cutter of Fig. 1, but provided with modified stripping means. These stripping means comprise a sleeve 32 which is connected to the centring pin 2 in a manner not shown in further detail, which sleeve has a collar-shaped end 33 which can move along the radial outside of the pins 12 for stripping off them a vent impaled on the pins 12. In a variant of this last embodiment according to

Fig. 16 the inside edge of the collar-shaped end 33a has a diameter which is smaller than the diameter of the circumscribed circle of the pins 12, recesses 10b being provided in the inside edge.

The embodiments of the stripping elements according to Figs. 12 and 15 have the special advantage that they need not be fixed in the tangential direction relative to the pins 12, which permits a simplified design of the vent cutter.

Fig. 17 shows a collar 6d which is slidable along the centring pin 2 in the axial direction and which is resiliently connected by means of a tension spring 34 to the centring pin end 4. When a vent impaled on the pins 12 is being stripped from them, the pulling force produced in the tension spring 34 in the process provides the necessary stripping force.

Fig. 18 shows a vent cutter in which the centring pin 2 is provided with a channel 36, through which a gas and/or a liquid under pressure can be supplied to nozzles 38 fitted at an acute angle to the axis of the centring pin 2. When the pins 12, from the position in which they are piercing a vent and the ends of the pins are in the holes 8, are moved along the nozzles 38, while gas and/or liquid under pressure flows out therefrom, the vent is stripped from the pins by the stripping force developed by the gas and/or the liquid.

Fig. 19 shows a centring pin 2 of which the thickened end 4 is inserted into the vent of a slaugh- tered animal. The rear face 5 of the centring pin end 4 is provided with pointed axial projections 40. Fitted in a coaxially movable manner relative to the centring pin 2 is a sleeve 42, of which the end is provided with a stripping collar 44 with a number of axial holes 46, which number corresponds to the number of projections 40. The sleeve 42 is situated in such an axial position that the pointed ends of the projections 40 are situated in the holes 46. The centring pin end 4, together with the stripping collar 44, can thus be inserted unimpeded in the vent of the slaughtered animal. This situation is shown in Fig. 19. If the centring pin 2 is then moved upwards so far that the rear face 5 thereof abuts against the bottom side of the stripping collar 44, then the pointed ends of the projections 40 project from the holes 46 and penetrate into the vent near the orbicular muscle 24. This is shown in Fig. 20. The vent is thereby fixed, and the centring pin end acts as a retaining element. The vent can now be cut out in the manner already explained by means of cutter 16 and, after the rectum 22 is pulled out of the slaughtered bird, is stripped from the projections 40 by moving the centring pin 2 and the sleeve 42 apart.

Fig. 21 shows a thickened centring pin end 4a, at the top side of which an annular recess 48 is fitted, which recess is partially covered by a stripping collar 44a firmly connected to the centring pin end 4a. On the bottom of the recess 48 rests a collar-shaped end 50 of a sleeve 52, which sleeve 52 can be moved in the axial direction over a distance determined by the bottom of the recess 48 and the bottom side of the stripping collar 44a. During such a movement, pointed projections 54 fitted on the end 50 move through the same number of holes 56 in the stripping collar 44a. The projections 54 can thus be inserted into a vent passed round the centring pin end 4a.

Fig. 21 shows the situation in which the centring pin end 4a with projections 54 sunk therein is inserted into the vent of a slaughtered animal; Fig. 22 shows the following stage, in which the sleeve is displaced in the axial direction and forced into the vent near the orbicular muscle 24 thereof. The vent is thereby fixed, and an incision can be made around the vent by means of the cutter 16. The vent fixed on the projections 54 can then be moved from the slaughtered animal, so that the rectum 22 is pulled out of the slaughtered animal.

Finally, the vent can be detached from the centring pin end 4a by moving the sleeve 52 to the bottom of the recess 48, as a result of which the pointed ends disappear in the openings 56 and the vent is stripped from the projections 54.

It will be clear that the vent cutter according to the invention is not limited to the examples of embodiments shown in the drawing. In particular, combinations of features of the various embodiments are possible.

Claims

1. Device for cutting out the vent of a slaughtered animal, in particular a bird, comprising: - a centring element (2, 4; 2, 4a);

- a rotary cylindrical surface shaped cutter (16) which can be moved coaxially relative to the centring element, and the inside diameter of which is greater than the outside diameter of the centring element; and - retaining means (12; 30; 40; 54) for fixing the vent, characterised in that the retaining means (12; 30; 40; 54) are movable coaxially relative to the cutter (16) and comprise a number of axially directed projections (12; 40; 54) whose ends can project into or through the vent for fixing of the vent, while provision is also made for stripping means (6; 6a; 6b; 6c; 33; 33a; 6d; 38; 44; 44a) for exerting a stripping force on a vent impaled on the projections of the retaining means, in the direction of the ends of the projections for stripping of the vent from them.

2. Device according to claim 1, characterised in that the stripping means (6; 6a; 6b; 6c; 38; 44a) are fitted in an axially fixed position relative to the centring element (2, 4; 2, 4a).

3. Device according to claims 1 - 2, characterised in that the stripping means (38) are designed for the production of a fluid flow to be directed along the projections (12) in the direction of the ends thereof or at an acute angle with the projections.

4. Device according to claims 1 - 3, characterised in that the stripping means (6; 6a; 33a; 6d; 44; 44a) comprise a radial collar of which the shape of at least one external or internal edge is at least partially com¬ plementary to that of the cross-section of the projec- tions (12; 40; 54) of the retaining means.

5. Device according to claims 1 - 3, characterised in that the stripping means (6; 6a; 6b; 33; 33a; 6d; 44; 44a ) are essentially disc-shaped or annular.

6. Device according to claims 1 - 3, characterised in that the stripping means (6c) have a number of radial projections of which the radius of the circumscribed circle is at least as great as the radius of the inscribed circle of the axial projections (12) of the retaining means.

7. Device according to claims 1 - 6, characterised in that the cutter (16) is provided along the inner periphery thereof behind the cutting edge (18) with an essentially annular thickened part (30) which can interact with the centring element (4) for supporting the vent during a movement of the centring element (2, 4) away from the slaughtered animal, with the cut-out vent fixed thereon by means of the retaining means (12) .

8. Device according to claim 7, characterised in that the difference between the inner radius of the thickened part (30) and the largest outer radius of the centring element (4) is smaller than the thickness of the orbicular muscle (24) of the vent.

9. Device according to claims 1 - 8, characterised in that the point of the projections (12; 40; 54) is situated on the radial outside of the retaining means.

10. Device according to claims 1 - 9, characterised in that the ends of the projections (12; 40; 54) of the retaining means, while projecting into or through the vent, can interact with the centring element (4) for fixing of the vent.

11. Device according to claim 10, characterised in that the rear face (5) of a widened end of the centring element (4; 4a) to be inserted into the vent is provided with one or more recesses (8; 48) for the accommodation of the projections (12) provided with a pointed end.

12. Device according to claim 11, characterised in that the rear face (5) of the widened end of the centring element (4; 4a) is provided with holes (8; 56) and fixed in a tangential direction relative to the projections (12).

13. Device according to claims 1 - 9, characterised in that the retaining means are formed by a widened end (4) of the centring element (2) to be inserted into the vent, on the rear face (5) of which element the projections (40) provided with a pointed end are fitted.