PROCESS AND APPARATUS FOR CUTTING SLAUGHTERED CHICKENS INTO PARTS
The invention relates to an apparatus for cutting slaughtered chickens into parts, in which the animals are suspended by the legs from a conveyor system and moved along an endless line formed by a drive unit, reversing sheaves and treating stations.
In the known apparatus for dissecting slaughtered animals, the cutting or splitting at the several treating stations is carried out by butchers who cut off parts of the animals by hand. As this known process is largely conducted by hand and therefore is an expensive one, it has been tried to find ways of operating the process at least in part with the aid of machines. To this end, devices have been proposed in which parts of the animals are cut off by means of motor-driven knives.
As the known process results in bony parts being damaged during the cutting, bone splinters are left in the meat, which is undesirable. In addition, the known process has the drawback that it permits only a limited rate of processing of the animals.
It is the object of the present invention to eliminate these drawbacks by removing parts of the slaughtered animals, which are suspended while moving along, by means of cutting devices. In principle this means that cutting devices go through a certain pattern of motion relative to the bone and in doing so keep up with the movement of the conveyor. In addition, the cutting requires exposure of the animal to a reactive force, which implies that the animal is maintained in a certain fixed position during the cutting. These requirements lead to a rather complex, bulky apparatus with separate drive units.
The present invention provides a less complex apparatus of the sort mentioned in the introduction. This is accomplished because
(a) the means of cutting and of fixing the animal rotate with the reversing sheaves and can move along a fixed path relative to the axle of the relevant reversing sheave;
(b) the means of suspension have been attached to the endless conveyor system at such a distance and location and the reversing
sheave can move in such a fashion that slaughtered animals hanging from them will invariably be positioned in the track of the fixing means;
(c) one or more fixed guiding means for rollers are provided round about the axle;
(d) the cutting and the fixing means are connected to rollers which can follow the path of the fixed guiding means during the rotation of the sheave;
(e) the movement and the track of the cutting and the fixing means are governed by the shape of the path permitted by the fixed guiding means during operation.
Preferably the sheaves turn the conveyor track through an angle of 180°. The cutting and the fixing means may be present round the circumference of 360° in a plurality, that is to say in a number that is an integer dividing 360°, within the limits of structural freedom. The requirement that the conveyor delivers the slaughtered chickens at the right distance and location must invariably be complied with. The examples of this patent application start from two sets of means, but in actual practice there is no such limitation.
The movement which the cutting and the fixing means make is brought about by the fixed guiding means and the associated rollers, whilst the drive is provided by the reversing sheave which is itself actuated by the conveyor and associated drive unit. Optionally, an appropriate reversing sheave may also serve as drive unit.
The animals are preferably graded by weight in categories of about 400 grams before the operation. This means they are differentiated according to size. As animals of different sizes are processed, the distance of the conveyor relative to the fixing means should therefore be adjustable.
The invention will new be elucidated by reference to two embodiments, without being restricted thereto, and the accompanying drawings in which
Figure 1 presents a lateral view of an apparatus for splitting a slaughtered chicken across the breast (a breast splitter);
Figure 2 presents a lateral view of a breast-meat cutter; and Figure 3 presents a lateral view of a so-called back stripper.
Figure 1 shows a reversing sheave 1 acting as guide to the conveyor system which also drives the said sheave and from which slaughtered chickens are suspended on hooks. The arrangement is such that during operation a chicken to be dissected arrives in front of a fixing bracket 2. During further rotation, the fixing bracket 2 moves outwards round a spindle 3, the movement being brought about by co-operation between a guide 4 and a roller 5 which is connected to the fixing bracket 3 through a shaft.
After a rotation through 90°, a knife 6 moves downwards along a guide 7. This movement comes about through the force of a roller 8 which co-operates with a fixed guide 9. Thus, the chicken's carcass is cut through from the inside. Obviously, the fixing bracket 3 must contain a split in order to let the knife 6 through. ultimately, the position is as outlined on the left-hand side in Figure 1 with corresponding reference numerals (a). As the second cutting device is disposed at an angle of 180° opposite the first one, this ultimate position again conforms to the initial position.
Starting from the general characteristics indicated hereinbefore, the breast splitter can in fact be described briefly as follows: The sheave 1 turns the conveyor track through an angle of up to 180° and is connected to a number of co-revolving vertical guides 7 for vertically movable knives 6, whose cutting edges face the axis of rotation.
During each rotation through an angle of 180° one knife 6 is moved down and up again as the rollers which can bring about the vertical displacement are guided according to a track 9 which proceeds at a constant distance from the axis of rotation and has a roughly sinusoidal course over 180° and a horizontal course (not shown) over a further 180°. The fixing means 2 are split into two halves in such a fashion that the knives 6 can move in between and they are, during rotation, moved towards the axis, because the guide 4 for the associated rollers 5 is disposed in a horizontally eccentric position
relative to the axis of rotation, such that the movement towards the axis takes place during the up and down movement of the corresponding knife 6.
The knives 6 preferably have a knurled cutting edge. The embodiment according to Figure 2 comprises a breast-meat cutter whose mode of operation includes cutting of the ribs. The figure shows a reversing sheave 11 acting as guide to the conveyor system which also drives the said sheave and from which slaughtered chickens are suspended on hooks. The arrangement is such that during operation a chicken arrives in front of a fixing bracket 12. The sheave 11 is connected to the actual rotating cutting device through a telescopic cardan shaft 11'. During rotation of the sheave 11 the fixing bracket 12 moves inwards round a spindle 13, the movement being brought about by co-operation between a stationary guide 14 and a roller 15 which is connected to the arm of the fixing bracket 12 through a shaft. The bracket 12 acts in conjunction with a backrest 12' so as to hold the chicken fixedly in place.
During the rotation and after the clamping, a knife 16 (for instance, a universal triitming knife) is moved down with its cutting edge following a certain path. This movement is brought about by the force exerted by a roller 18 which acts in conjunction with a stationary guide 19. The downward movement of the knife 16, which is in essence curved, is corrected to a more rectilinear movement by displacing the co-revolving fulcrum 17 of the roller spindle and the knife's arm away from the axis of rotation by means of a rigidly mounted eccentric 20 (hence also a guide). The ultimate position so obtained is shown in Figure 2 on the left-hand side with the corresponding reference numerals (a). As the second cutting device is disposed at an angle of 180° opposite the first one, the ultimate position again conforms to the initial position.
Starting from the general characteristics indicated hereinbefore, the breast-meat cutter can in fact be described briefly as follows. The sheave reverses the conveyor track through an angle of up to 180° and is movably connected to a number of co-revolving knives and associated fixing brackets. During rotation, every knife is moved down with its
cutting edge by a co-operation between a roller and a stationary guide, this movement being corrected by a second guide (eccentric) which displaces the fulcrum of the roller spindle and the knife's arm away from the axis of rotation. During the rotation on an axis, a fixing bracket has been moved inwards through the joint action of a stationary guide and a roller whose spindle is connected through a fulcrum to the fixing bracket which acts in conjunction with a backrest. The guides are designed such that fixing takes place before the knife cuts.
As a matter of course, the distance between conveyor system and fixing bracket is adjustable according to the size of the slaughtered animals also in this apparatus.
The embodiment according to Figure 3 comprises a so-called back stripper, that is to say, an apparatus of the type according to the invention which is capable of removing the back meat. Again, the figure shows a reversing sheave 21 acting as a guide to the conveyor system which also drives the said sheave and from which slaughtered chickens are suspended on hooks. The component parts are arranged in known fashion such that during operation the chickens to be processed arrive each in their turn with their breast facing the axis of rotation in front of a fixing bracket 22, 22', with leg spreader 22' ', 22'''.
The sheave 21 is connected through a shaft 23 to a co-revolving drum 24 to which a number of co-revolving vertical guiding means 25, 26 are attached in order to permit vertical displacement of both the fixing bracket (s) 22 and one end of the arms 27, 27' on whose other end a stripping knife 28, 28' is rigidly mounted.
A guide 29 for the rollers 30, 30' is capable, upon rotation of the drum 24, of moving the fixing bracket (s) 22, 22' connected to the rollers upwards along the guide rods 25, 26 against a spring pressure.
Also, upon rotation of the drum 24, the joint action of a second guide 31 and the rollers 32, 32' which are mounted on the end of the arms 27, 27' opposite the knife end causes these arms to move along the
guide rods 25, 26, in such a fashion that upon rotation through 90° the guiding means are moved down with the fixing brackets 22, 22' maintained in their lowest position, whereupon when the fixing bracket has been brought to its topmost position, it will retain this position through 180° Upon rotation through the subsequent 90° the initial position will be reached again.
The line generated by the stripping knives 28, 28' is, in addition, determined by the joint action of the rollers 32, 32' and a stationary guide 33, whilst the rollers 32, 32' are rigidly mounted on the end of the arms 27, 27' facing the knives.
The working point of the arms is not moved forcibly, but springs 34, 34' provide the requisite flexibility between the roller guides 30, 31, 31' and the ends of the arms 27, 27'. The springs 35, 35' which act in conjunction with the fixing brackets 22, 22' also promote flexibility.
Starting from the characteristics described hereinbefore, the back stripper can in fact be specified briefly as follows. The sheave 21 reverses the conveyor track through an angle of up to 180° and is connected to co-revolving vertical guide rods 25, 26, which guide the movement of the fixing brackets 22 with leg spreaders 22 as well as one end of the arms 27 on whose other ends stripping knives 28 have been mounted.
The fixing brackets 22 and the ends of arms 27 are each displaced through the joint action of rollers 30 or 32 and guiding means 29 or 31 which remain at a constant distance from the axis of rotation, and they move simultaneously up and down the vertical guide rods 25, 26. This movement is constituted such that during rotation through the first 90° the fixing brackets 22 are in their lowest position and the arm is moved down, during rotation through the following 180° the fixing brackets are maintained in their topmost position and the ends of the arms 27, 27' remain in bottom position, whilst during rotation through the subsequent 90° the initial position is resumed.