APPARATUS AND METHOD FOR PLACING ADVANCE FOOD PRODUCTS
DESCRIPTION OF THE INVENTION The present invention relates to a positioning element for placing advance food products according to the preamble of claim 1. The invention also relates to an apparatus for placing food products, comprising the positioning element. The invention finally also relates to a method for placing food products, according to the preamble of claim 13. The advancement of food products in a conveyor has hitherto usually taken place by guiding elements which are arranged in a fixed position adjacent to and above the conveyor. Advance foodstuffs, for example (semi-products of) sausages in particular, which are located in a location where they are forced against the products placed in a fixed position, will thus be pushed to the side by the guide element arranged in a position fixed. Such a solution can be manufactured in a very advantageous and consistent manner, and also requires little maintenance and is not susceptible to malfunction. A drawback of this ting method of placing food products that advance on a conveyor is that some of the products to be placed are deformed under the influence of the guide arranged in a fixed position (the sausages can be bent, for example). Another drawback is that some of the food products can only move temporarily; as soon as the product is no longer in contact, in a number of cases it can return, to a greater or lesser degree, to the starting position before it is coupled by the guide element arranged in a fixed position. Japanese Patent JP 60-102316 describes a device for collecting and arranging transferred objects in a single line. The objects are moved by a haulage carrier and will be contacted due to forward movement with the right and left guide members swinging in the broad direction of the hauler. The right and left guide members move through a mechanism of power to arrange the objects gradually in a smaller number of lines. Finally all the objects are arranged in a line in the final output and sent in a passage. Due to this construction the objects that are transported in plural lines can be arranged in a simple line. However, this construction is only applicable for products to be aligned in a single row and also has the disadvantage that it requires substantial space. The object of the invention is therefore to provide means and a method for placing advance food products in plural lines, so that the disadvantages of the prior art described in the above can be alleviated or avoided. The present invention provides for this purpose a positioning element for placing advance food products, according to claim 1. The positioning element can thus be used to arrange between two rows of advancing food products and to exert a placement effect on two directions (ie in relation to two attached rows of food products). In addition to the double effect of the positioning element according to the invention, this double effect, the placement of two rows of food products, is realized without a substantial increase in the costs for the action on two sides of the positioning element on one of the positioning elements that act sideways according to the previous technique. The invention further provides the option of placing, including separating, rows with a small space or even partial overlap of the elongated food products. Further explanation is provided in the following with respect to the separation effect of the positioning element according to the invention. Furthermore, the positioning element has the advantage that the coupling member can be pressed for a relatively short time against the products to be placed and then released there again. A food product, as for example a sausage can be forced in a desired direction with one or multiple successive strokes (alternating, pushing) without the product resting on or against a guide element for an excessive time. The positioning element according to the invention enables placing (aligning) food products that conserve less their shape without this having to result in the deformation of the food products. The opportunity for products to return to the initial position after placement may also be reduced with that placement element. US Patent 3,067,558 discloses a sausage packing machine comprising a substantially horizontal continuous chain conveyor having a superior range for receiving individual sausages and for transporting sausages. On opposite sides of the chain conveyor a pair of converging continuous guide belts (C) is located to align the sausages on the chain conveyor. This document also does not provide a solution for aligning plural rows of food products. U.S. Patent 6,454,257 discloses an article advancing apparatus for lateral straightening of sheet material located on a conveyor including a pair of vertically opposed timing belts. A belt is adjustable by the product width as well as the flow neck, the other belt oscillates between a reference position and a pull position to realign those items of the flow that are out of alignment. Again, this document does not provide a solution for aligning plural rows of products. In a preferred embodiment the coupling member is provided with a substantially flat engagement side. With the flat coupling side the damage / deformation opportunity of the products is minimal and it is also easy to clean the coupling member. In an advantageous variant, the coupling member can rotate rotatably around a fixed rotation arrow. This rotary arrow can, for example, run parallel to a substantially flat coupling side, or can even be placed in the plane opposite the coupling side. The arrow can also advantageously be located on a front side of the positioning element, wherein the displacement means can be inversely coupled in the coupling member at a distance from the rotation arrow. This construction can also be given to a simple and reliable way. On the other hand, as an alternative, it is also possible to give the rotation arrow a transferable shape, or to make it adjustable in such a way that the angle encompassed by the rotation arrow and the active surface of the conveyor is adjustable. Depending on the circumstances, the positioning action of the coupling member can thus be adjusted. However in order to bring the products to a correct position for positioning which lies very far outside the alignment limits to be realized, it is advantageous if the coupling member is provided with a height that is gradually increased in the direction of transportation of products for placement. The positioning element is provided with a contact edge with a height that increases in the direction of transport on which the food products can slide upwards as they advance. Under normal conditions the intermittent movement of the coupling member will however ensure that, during each reciprocal hit of the contact member, the food products will alternate some distance in the direction in which the products should eventually be placed. It can also be made possible, for example, to completely separate one from the other (align with a fixed spacing) two rows that lie adjacent to one another with overlap. The displacement means can be formed by a rotatable cam roller which is associated with the coupling member by at least one rod. The means of travel are easy to manufacture and maintain, although other various displacement means may also be applied, such as for example pneumatic or hydraulic cylinders. The invention also provides an apparatus for placing advance food products, according to claim 6. The movement in the present can be parallel to the part of the conveyor that supports the food products. For the advantages of the apparatus reference is made to the advantages stipulated in the above with respect to the positioning element according to the invention; These include being simple, consistent, little susceptible to malfunction, without deformation of products, easy to clean and so on. The positioning element can also be associated with the conveyor for steering purposes, for example, in that a roller is coupled to the conveyor in such a way that the latter is directed accordingly, which roller then carries out a displacement of the coupling member, optionally by means of transmission. Such a direction makes a separate power source to perform intermittent movement of the coupling member unnecessarily, and it is also very simple to synchronize the movements of the conveyor and the coupling member. If the positioning element moves relative to the conveyor in such a way that in the direction of transport the final position of the coupling member is reached also in the situation in which the food products are alternating, it becomes possible to drive the food products to the desired position in successive stages. This results in a controlled placement process with predictable results. When the conveyor is adapted to displace at least two rows of food products, between whose rows of food products the displaceable coupling member of the positioning element is movable, a single positioning element can provide the separation of the rows. This results in a good use of space and available means. In the case where the apparatus is provided with at least two positioning elements arranged on opposite sides of a row of products for placement as part of the double row of products as described, it becomes possible to completely control the position of these products in one direction (perpendicular to the transport direction). It becomes possible to move the products without taking into account the direction in which they have an undesirable starting position. In order to keep the products in the direction of movement, it is desirable to provide the protractor with protruding elements that engage the food products. The force exerted on a food product with a positioning element can thus also be controlled; after all there is less possibility, or not, that the food product moves in an undesired direction. In order to prevent the positioning element from jamming or damaging the conveyor, it is desirable that the coupling member be intermittently movable at a distance from the side of the conveyor supporting the food products. Moreover, the invention provides a method for placing advance food products, according to claim 12. Due to this method the products will be displaced to a minimum distance and a double placement effect can be obtained with a single coupling member. At least some of the positioning products can be carried upwards on the coupling member and then released through the coupling member by the intermittent movement of the coupling member. This also makes it possible to place products that are partially on the opposite side (the wrong or undesirable side for the product in question). It is also possible for a row of food products placed successively as part of the double row of products to be placed by the double positioning of the coupling member to engage on opposite sides by intermittently reciprocating coupling members. The position of the food product in the direction perpendicular to the transport direction (and parallel to the conveyor) is now completely controllable; a product can be selectively coupled by one of the two coupling members and driven in the desired position. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will also be illustrative based on the non-limiting exemplary embodiments shown in the following figures. In the present: Figure 1 shows a perspective view of a positioning element according to the invention, Figure 2 shows a perspective view of a positioning apparatus according to the invention with a double row of sausages for alignment, and Figure 3 is a top view of a part of the positioning apparatus for alignment showing only a single row of sausages. Figure 1 shows a positioning element 1 with a coupling member 2 which is provided with a contact side 3 for coupling into products for placement, which are not shown in this figure. The positioning element 1 is provided with a rotation arrow 4 which can be supported mounted in the fixed world. On the side of the coupling member 2, remote from the rotation arrow 4, a coupling rod 6 is rotatably connected thereto by a coupling part 5. By means of a second coupling part 7 the side of the coupling rod 6, remote from the positioning element 1, is rotatably coupled to a cam 8 of a disc 10 directed by an electric motor 9. Through the rotation of the disk 10, the coupling member 2 will begin to make a reciprocal swing movement around the rotation arrow 4. Figure 2 shows a perspective view of the positioning apparatus 1 according to Figure 1 in combination with a conveyor 20 with its two rows 21, 22 of sausages 23 for alignment, moves in the transport direction Pl. The conveyor 20 is provided with right portions 24 between which the sausages 23 are placed. The sausages 23 therefore have only one degree of freedom, parallel to the right portions 24. In the initial feed the sausages 23 are not yet properly aligned in two rows; it then has a more or less random orientation in the direction parallel to the right parts 24. This random orientation of the sausages 23 even goes so far that two adjacent sausages 23 may be in contact with each other or may even be partially overlapped. The separation of the pairs of sausages located successively on the conveyor 20 can be in a different location in each case, which makes it difficult to separate the two rows 21, 22 of sausages 23 for alignment. When the sausages 23 reach the coupling member 2 of the positioning element 1, some of the sausages 23 will rise on an upper edge 25 of the coupling member 2 while other sausages 23 are not initially touched by the coupling member 2. Due to the rotation of the disk directed by the electric motor 9, the coupling member 2 will reciprocally reciprocate in the intermittent manner by the association bar 6. The rolling of the coupling member 2 will become increasingly larger as seen in the direction of one of transport Pl, such that the sausages (depending on the transport speed relative to the frequency of intermittent rolling motion and the position of start of a specific sausage 23) are placed in a number of stages in the desired position (aligned) by the coupling member 2. The sausages 23 will slide upwardly on the edge 25 above the first contact with the coupling member 2 will be removed from the upper edge 25 in one or more stages by the intermittent swinging movement of the coupling member 2. It is also possible to separate fragile sausages 23 (or other delicate foodstuffs) that are oriented in overlap and / or other complex manner. Figure 3 shows a top view of a partial view in the positioning apparatus 1, the coupling member 2 of which engages in only a single row of sausages 30 shown for alignment on one side, the second row of sausages 30 not It is shown in this figure.