Patent Application
20150064315
This application claims priority to European Patent Application No. 13183249.5 filed Sep. 5, 2013, the disclosure of which is hereby incorporated in its entirety by reference.
1. Field of the Invention
The present invention relates to an apparatus for weighing dough. More in particular, the invention relates to a device for conveying a plurality of endless dough pieces, extending essentially in parallel lanes on said conveyor in a direction of conveyance.
2. Description of Related Art
Such devices are known in the art, for example from the European Patent EP 2 116 821 in the name of the same applicant. The device disclosed therein has proved to be an improvement over the prior art, but a demand for further development has appeared.
In particular, when applied in circumstances wherein a plurality of continuous dough pieces is processed that appear not to have equal average weight distributions, it is considered disadvantageous that an average of multiple dough pieces is weighed, in order to determine a common cutting length for all pieces, based on a desired weight per piece.
One solution may be to split up the single conveyor into a plurality of small conveyors, one for each (endless) dough piece, but this has several disadvantages. The construction is complex, and since there is a space in between the separate conveyors, there is a higher risk of filthiness such as dough and flour residue occurring in between the conveyors, which leads to more maintenance and possible negative influence on the weighing performance.
Under some circumstances the use of one or more weighing rollers may be desired, positioned under the endless conveyor, for measuring the dough conveyed by the conveyor. However, such solution has the disadvantage that a weight-curve of a dough piece measured has a triangular deformation, and it has appeared to be very sensitive to imperfections in the conveyor belt.
It is a goal of the present invention, to provide a solution that does not have the above disadvantages, or at least to provide a useful alternative to the state of the art.
The invention thereto proposes a device for weighing dough, comprising an endless conveyor for conveying a plurality of endless or continuous dough pieces extending essentially in parallel lanes on said conveyor in a direction of conveyance, a weighing-unit, arranged under the endless conveyor, wherein the weighing unit comprises multiple weighing rows, spread over the width of the conveyor, each row comprising at least one rectangular weighing section, for independently of the other weighing sections weighing a different dough piece of said plurality of endless or continuous dough pieces.
With respect to the state of the art, the present invention takes away the disadvantage that a weight measurement has a trapezium- or V-shaped curve. Preferably, according to the present invention, the length of a rectangular weighing section is chosen such that it matches the length of a dough piece to be measured. A measurement is then performed to determine the weight of the piece of dough on the weighing device. The measured weight is compared to an expected and/or desired weight of the dough piece. If the weight is higher than the expected or desired weight of the measured length, a cutting operation may be performed earlier, that is, a shorter piece may be cut off the endless dough piece in order to obtain a desired weight, or the other way round, if the weight is lower than the expected or desired weight of the measured length, a cutting operation may be performed later, that is, a longer piece may be cut off the endless dough piece in order to obtain a desired length.
According to the present invention, a method for measuring the weight of a dough piece with U, D (unit, decimal) times the length of a weighing section of a device as described above, wherein each row comprises one rectangular weighing section, comprises the steps of:
F. Adding up the weights thus obtained.
However, it is not always possible to have the rectangular weighing section corresponding with the length of a dough piece to be cut off from the endless or continuous dough piece. Possibly because the length of the dough piece to be cut is too long, possibly because it changes during use. Furthermore, in some cases an alternative to the above method may be desired.
Therefor, in a further embodiment, at least one row comprises a plurality of weighing sections, arranged behind each other in the direction of conveyance. At least one of the weighing sections may have a different length than the other ones, or in particular, each of the weighing sections has a different length.
In particular, the weighing sections are arranged adjacently behind each other.
Such configuration may them be used in a method for measuring the weight of a dough piece, comprising the steps of:
When differences are used, it may even be necessary to subtract the weight measured by a weighing section.
For receiving weight information from the weighing sections and displacement information of the conveyor, and determining the weight per unit of length of the dough on each lane, the device may comprise a processor, which may further be configured to generate a control signal for a further processing device of each lane, like a cutter, for controlling the further processing device based on the determined weight, such as the cumulative weight per lane.
In yet another embodiment, the weighing unit comprises a weighing area, wherein weighing rows and weighing sections are configurable. With this solution, every desired shape of dough piece to be weighed can be weighed, with one and the same device, and a change in a desired shape just requires reconfiguration of the device. The weighing area may thereto for instance comprise a weighing matrix, with weighing cells, from which weighing sections can be defined. These cells may have a size equal or less than 3×3 cm, preferably equal or less than 2×2 cm, and even more preferably equal or less than 1×1 cm.
It is possible that an expected length of a dough piece on a lane is not an exact multiple of weighing cells of sections. In such case, a somewhat shorter or longer piece of dough can be measured, wherein the weight is determined by extrapolation or interpolation respectively. Preferably the measurement is performed on actual dough that is to form part of the piece to be cut, that is, a part of the dough piece is weighed twice, for which a correction is applied later on.
A method according to the invention for measuring a weight of a dough piece with the above described device comprises the steps of:
Since a general purpose of the device according to the present invention is to weigh an amount of dough that needs to be cut from the endless dough sheet, it may further comprise either one knife that can be displaced over the width of the conveyor, or a plurality of cutting units downstream the weighing units, for separately and independently cutting each of the parallel dough pieces, based on the determined weights by the weighing sections.
Thereto, the invention also relates to a method for controlling a cutting device for an endless dough piece, comprising:
After cutting a dough piece has been cut, the cutting line forms a new initiation point for a next dough piece, and weight measurement takes place from the new initiation point.
The invention will now be elucidated into more detail with reference to the following figures. Herein:
For ruling out, or at least avoiding influence of the tension of the conveyor on the measurement, the conveyor is arranged slackly in a width direction. Thereto, it may be provided with one or more transition parts, arranged slightly inward of the outer edges of the conveyor in the width direction, and wherein the transition parts are arranged to provide the middle part in between the transition part with a substantially flexible suspension in a direction perpendicular to a plane defined by the width direction and the direction of conveyance.
In the embodiment shown, the outer edges of the conveyor comprise a toothed belt, and wherein the device comprises gear drive for driving the conveyor. A drive configuration with a toothed belt is free of slip, and allows to determine and to keep track of the exact position of the belt. The conveyor may preferably be driven at both sides, and may further comprise a line, extending over the with of the conveyor perpendicular to the direction of conveyance, for verifying a correct placement of the conveyor with respect to the gear drive. Other belts may be used as well in combination with the features of the present embodiment.
The device further comprises a weighing-unit 12, arranged under the endless conveyor, comprising multiple weighing rows 13, 14, 15, 16, spread over the width of the conveyor, each row comprising two rectangular weighing sections (normally covered by the conveyor) 13a, 13b, 14a, 14b, 15a, 15b, 16a, 16b, for independently of the other weighing sections weighing a different dough piece of said plurality of endless or continuous dough pieces.
In the embodiments from
The device according to the invention may even have an exchangeable weighing section, that allows to quickly replace the weighing tables. In such case, the configurations from
The matrix may be formed by a touch-screen like device over which the endless conveyor moves, or a configurable array of sensitive piezo elements, or a foil with a printed circuit that contacts locally when a pressure is applied, or other solutions known in the art.
Not only can a weight be determined very precisely with this embodiment, but it is also possible to determine shapes of dough pieces conveyed over the conveyor.
| Number | Date | Country | Kind |
|---|---|---|---|
| 13183249.5 | Sep 2013 | EP | regional |
