FIELD OF THE INVENTION

The present invention relates to feeder system for conveying and discharging at least one food product into a receptacle, and to a multihead weighing system comprising a plurality of such feeder systems.

BACKGROUND OF THE INVENTION

In the foodstuffs industry there is a need for sorting products or articles at high speeds or throughputs according to various physical characteristics such as size, color or weight, alternatively by any combination of these. Industrially packed food products, such as pieces of poultry, are often packed in packages of approximately equal weight, independent of the number of pieces included in the package. Therefore, many packages of food products include more than one individual product, i.e. the packages normally include at least two products. Some product packages, such as packages of chicken breast, typically include three pieces in each package, however, the number may be greater such as four or five pieces within the same package, as long as the packages all have approximately the same weight.

In order to ensure that food products of varying weight may be combined in packages having approximately the same weight, a multihead weigher may be used. A multihead weigher, which in principal is known in the prior art, receives pieces of food products and distributes them among a large number of weighing systems, such as 5-50, preferably 8-20 weighing systems, which typically has the form of receptacles. A computer is then used to calculate the most favorable combination of receptacles to reach a target weight, and the chosen receptacles are subsequently emptied such that the food products contained in each chosen receptacle leave the receptacle and end up in a common package. It is thereby preferred to keep the weight of the products contained within each receptacle as close as possible to a predetermined level.

EP 2 484 593 discloses a weighing system where no more than one food product at a time, is received within each receptacle. This system describes a determination unit such as a radar determination unit, a photocell determination unit or a laser determination unit, that is placed at the outlet end of the weighing system. The determination unit controls which operational mode the feeder for conveying the food products from the inlet to the outlet end has to run in, and thereby ensures, that only one food product will leave the outlet end and into the receptacle. The problem with this reference is however the fact that the determination unit is placed at the outlet end of the weighing system which means that it gets dirty very fast. This does not only make it unreliable but can also halt the subsequent processing. Also, it is not only difficult to clean the determination unit but the cleaning process can easily damage the determination unit, which obviously increases the maintenance cost significantly. Further, all the different types of determination units require visible cables due to the location and the design of the feeding channels.

The inventor of the present invention has appreciated that there is thus a need for an improved feeding system that requires much less cleaning and thus reduces the maintenance cost significantly and has in consequence devised the present invention.

SUMMARY OF THE INVENTION

It would be advantageous to achieve such an improved feeder system that requires much less cleaning and is more reliable. In general, the invention preferably seeks to mitigate, alleviate or eliminate one or more of the above mentioned disadvantages singly or in any combination. In particular, it may be seen as an object of the present invention to provide a system that solves the above mentioned problems, or other problems, of the prior art.

To better address one or more of these concerns, in a first aspect of the invention a feeder system is provided for conveying and discharging at least one food product into a receptacle, comprising:

• an inlet-end for receiving food products,

• an outlet-end for discharging at least one of said food products into said receptacle

positioned below the outlet end,

• a feeder unit operated by a feeder-control unit for conveying the food products from said inlet-end towards said outlet-end, and

• a determination unit, wherein said determination unit comprises an optical device positioned such that a light beam emitted by the optical device crosses a fall path of the at least one of said food products when discharged from said outlet-end into said receptacle, where the optical device is operable connected to the determination unit that determines when food objects fall from said outlet- end towards said receptacle, and

wherein said optical device is positioned such that the direction of the light beam forms an angle in relation to a normal axis of an opposing plane of the receptacle. The fact that the optical device, which in one embodiment is a photocell, is positioned e.g. below the outlet-end means that the pureness of the optical device is present much longer than if the optical device would have been positioned at the outlet-end. The fact the light beam will form an angle in relation to the normal axis, i.e. the axis that is perpendicular to the opposing plane, it is ensured that reflection from the light beam will be minimized. The position of the optical device should preferably be such that a light beam emitted by the optical device crosses the fall path of food products being discharged from the outlet- end and fall into the receptacle positioned below the outlet end, so that the light beam is disturbed each time a food product falls into the receptacle.

The optical device may in an embodiment be a photocell, for example a photocell of the reflection type, where the photocell radiates a light beam and where it detects an item in front of it based on alterations of the light reflected from the item. Other types of photocells may be used as well.

The optical device may be positioned e.g. essentially between said receptacle and said outlet-end, essentially below said outlet-end, essentially adjacent to a fall path of the at least one of said food products and/or in other suitable manner such that a light beam emitted by the optical device crosses a fall path of the at least one of said food products when discharged from said outlet-end into said receptacle.

In one embodiment, said opposing plane of the receptacle is a substantially flat plane. Accordingly, the viewing angle of the beam may thus be increased compared to if the beam would be parallel to the normal axis. In that way, it is ensured that the food products that fall down into the receptacle will intersect with the beam which indicates that a food product is present in the receptacle. The surrounding is typically a number of metal/steel surfaces which reflect the light emitted from the photocell easily, but by selecting the optimum angle it is thus prevented that the photocell will be disturbed by its own reflection.

In one embodiment, based on monitoring whether a food object fall from said outlet- end towards said receptacle the determination unit determines whether the receptacle is empty or not. In one embodiment, in case said determination unit determines that the receptacle is empty the feeder-control unit starts the feeder unit, which may be a screw feeder, or increases the conveying speed. In another embodiment, in case said determination unit determines that the receptacle is not empty the feeder-control stops the feeder unit. In yet another

embodiment, in case said determination unit detects that said optical device is continuously activated, the feeder-control unit turns the screw feeder a predefined number of rotations. Accordingly, it is possible to operate the conveying of the food products by means of determining the status of the receptacle, where the operational mode of the feeder unit is adapted to the status of the receptacle.

According to a second aspect, the present invention relates to a multihead weighing system including a centrally located receiving section for receiving said food products, said multihead weighing system comprising a plurality of said feeder systems distributed around the said centrally located receiving section with the inlet-ends position below the periphery of said centrally located receiving section.

According to a third aspect, the present invention relates to method of conveying and discharging food products comprising

• receiving food products at an inlet-end,

• conveying the food products from said inlet-end towards an outlet-end in a controllable way to discharge at least one food product into a receptacle positioned below the outlet- end, and

• determining whether or not one or more food products have been discharged from said outlet-end, wherein said determining is performed by an optical device positioned such that the light beam emitted by the optical device crosses a fall path of the at least one of said food products when discharged from said outlet-end into said receptacle, where the optical device is operable connected to the determination unit that determines when a food object falls from said outlet-end towards said receptacle, and

wherein said optical device is positioned such that the direction of the light beam forms an angle in relation to a normal axis of an opposing plane of the receptacle.

The optical device may be positioned e.g. essentially between said receptacle and said outlet-end, essentially below said outlet-end, essentially adjacent to a fall path of the at least one of said food products and/or in other suitable manner such that a light beam emitted by the optical device crosses a fall path of the at least one of said food products when discharged from said outlet-end into said receptacle.

In one embodiment, said determining includes determining whether a food object falls from said outlet-end towards said receptacle and based thereon whether the receptacle is empty or not.

In one embodiment, in case the determining indicates that the receptacle is empty the conveying of the food products is started or increased. This may be referred to as a first operation mode. In another embodiment, in case the determining indicates that the receptacle is not empty the conveying of the food products is stopped. This may be referred to as a second operation mode. In yet another embodiment, in case said determining indicates that said light beam is continuously interrupted indicating that a food products is partly freely hanging from said outlet-end, the feeder-control unit turns the screw feeder a predefined number of rotations. This may be referred to as a third operational mode.

According to a third aspect, the present invention relates to a computer program comprising instructions for carrying out the steps of above mentioned method steps when said computer program is executed on a suitable computer device. In general the various aspects of the invention may be combined and coupled in any way possible within the scope of the invention. These and other aspects, features and/or advantages of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will be described, by way of example only, with reference to the drawings, in which

figures 1 and 2 depict a perspective view and a front view of a weighing system according to the present invention comprising a multihead weighing system, and

figure 3 shows a closer view of a feeder systems according to the present invention shown in figures 1 and 2.

DESCRIPTION OF EMBODIMENTS

Figures 1 and 2 show a perspective view and a front view of an embodiment of a multihead weighing system 100 according to the present invention comprising a centrally located receiving section 201, and a multiple of feeder systems 101 distributed around the centrally located receiving section with the inlet-ends 104 positioned below the periphery of said centrally located receiving section 201. It is appreciated that the general functioning of such a multihead weighing system 100, e.g. the general principle of how to generate portions of fixed target weight, is well known to a person skilled in the art, but an example of this functioning is e.g. disclosed in EP2484593, hereby incorporated by its entirety by reference.

In this embodiment, the multiple of feeder systems 101 shown in a more detailed way in figure 3 comprises an inlet-end 104 for receiving food products, an outlet-end 105 for discharging the food products into a receptacle 202 positioned below the outlet-end and a controllable screw feeder 103 operated by a controlling unit (not shown) for advancing the food product(s) from the inlet-end 104 towards the outlet-end 105. The feeder system 101 further comprises a determination unit 102 positioned below the outlet-end 105 for determining whether or not one or more food products are present in the receptacle 202, e.g. based on information as regards whether or not the receptacle has been emptied, as it will be apparent to a skilled person.

In an embodiment, the determination unit is an optical device that during operation emits a light beam as indicated by dotted line 203 that crosses the fall path of the at least one of said food products 204, but this optical device determines when a food object has fallen from the outlet-end 105 and into the receptacle 202 and based thereon determines whether the receptacle is empty or not. The determination unit 102 might however just as well comprise any other type of a sensor such as one of a type that serves a surveillance function to detect motion, an ultra sound sensor, a radar type sensor or the like.

In one embodiment, the determination unit may also be utilized to determine the number of food objects in the receptacle at all times. This may however be bound to certain criterion such as that the distance between adjacent food objects is above a certain threshold level, .e.g. more than 5cm. Such a counting might be based on that when the food product falls a signal is triggered indicating that a first object is present in the receptacle. Moreover, if two or more objects would fall down before the receptacle is emptied the determination unit counts the number of the subsequent food products in the receptacle. When food product(s) is released from the receptacle, the counting may be adjusted accordingly and set to zero. In one embodiment, no more than one food product is present in the receptacle at a time. If however the objects form a kind of a lump this lump would be considered as a single food product.

In one embodiment, the optical device 102, which preferably is a photocell, is positioned such that the direction of the light beam forms an angle in relation to a normal axis of an opposing plane of the receptacle 202, or at an angle in respect to the transport path of the food products when being moved from the inlet-end 104 towards the outlet-end 105. This angle is preferably selected such that reflection from the surroundings, i.e. the metal/steel components, is minimized, which would otherwise disturb the operation of the photocell.

In one embodiment, the functioning of the feeder system is based on three different operational modes:

The first operational mode for the feeder is used, when no food product has been detected passing below the outlet-end or is present below the outlet end (hanging over the edge and in front of the determination unit). The average velocity used in the feeding mechanism is high, since the time lost between two individual food products should be as short as possible.

When the determination unit detects a food product below the outlet end, the second operational mode is used. In the second operational mode, the feeder is temporarily stopped in order to avoid any second individual food product to enter the storage receptacle before the receptacle, which may be a weighing receptacle, is emptied. When the storage receptacle is emptied, the weighing receptacle below detects the weight of the food product.

If no food product is dropped into the weighing receptacle, due to the fact that e.g. the food product was only hanging on the edge of the outlet end and thereby being detected by the determination unit, a third operational mode is used. In the third operational mode the feeder turns a predefined number of steps followed by the storage receptacle emptying and letting food products fall into the weighing receptacle. This cycle continue until the weighing receptacle detects food product being dropped into it.

If food product is dropped into the weighing receptacle, the first operational mode is used, until the determination detects food products below the outlet end.

The feeder unit may be powered by a motor, which in turn is controlled by a control unit, transports the food products from inlet-end to an outlet-end, located opposite the inlet-end as shown here.

As already addressed, the receptacles 202 may be a weighing receptacle that are utilized in generating weight portions of fixed target weight, where the most appropriate combination of the weighing receptacles is selected so as to minimize the overweight of the portions. It is therefore of outmost importance to ensure that the tz ^' me where the (weighing) receptacles are empty is minimized.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.