Patent Description:
In the practice, it is known that, for example in the production of sausage-shaped products, filling material is fed by a filling device through a filling tube of a clipping device into a tubular casing, which is stored on the filling tube and which is closed at its front end by closure means, like a closing clip. The tubular casing is pulled-off from the filling tube while being filled. After a predetermined volume of filling material is filled into said tubular casing, a displacement device with a first and a second pair of displacement elements forms a plait-like portion of the tubular casing and the clipping device places and closes at least one further closure means at the plait-like portion forming the back end of the sausage-shaped product by respective closing tools, which are reversibly movable towards the plait-like portion.

A clipping device and a method for controlling a clipping device for producing sausage-shaped products and a method for detecting casing material bursts is already known from <CIT>. The clipping device fills material into a tubular casing already closed at its front end by a clip, and places one further clip on the back end of the tubular casing. A control unit controls the clipping device, a sensor measures the pull-off length of the tubular casing pulled off from the filling tube and a second sensor measures the movement of the filling material while being fed to the tubular casing. The control unit compares the ratio of the captured values of the pull-off length of the tubular casing and the movement of the filling material to predetermined comparison ratios to detect casing material bursts.

A filling device for filling viscous filling material in a tubular casing with a sensor for monitoring the drawn length of the casing from the supply of the casing is already known from <CIT>. The filling device comprises a closing valve, a filling tube arranged in filling flow direction of the filling material behind the closing valve, a clip setting and clip closing device arranged in filling flow direction of the filling material behind the filling tube, a supply of tubular casing at least partially arranged on the filling tube and a continuously measuring sensor for direct or indirect detection of a length of the casing material drawn from the supply. The output signal of the sensor is able to control at least the closing operation of the closing valve through which the pressurized filling material can be supplied to the filling tube.

Further, <CIT> discloses a sealing device comprising a forming shoulder and a sealing tool, which is configured to seal opposing longitudinal edges of a foil to form a tubular casing of a sausage-shaped product.

From <CIT>, an apparatus for the production of film tube, which can be filled with liquid, viscous or granular filling material, from a film strip is known. In said apparatus, a film strip provided on a supply roll, is guided over a number of direction-changing rollers towards a forming shoulder, where the film strip is formed into a film tube and sealed by a sealing device, and forms a supply of film tube. A writing unit applies markings on the film strip in predefined spacings. Based on the markings, a first reader registers the length of the film strip drawn off from the supply roll. A second reader detects the length of sealed film tube pulled off from the film tube supply. The sealing operation is controlled based on the signals of the reader, such that a predetermined supply amount of film tube is maintained.

Document <CIT> further discloses an additional system for manufacturing sausage-shaped products having a tubular casing provided with at least one imprint.

The above-mentioned disclosures provide means for monitoring the filling process of sausage-shaped products to either detect incidents during filling or provide continuous manufacturing. However, the prior art is silent about the improvement of accuracy in the production process, as there can be measurement uncertainties during production, e.g. among filling speed, density differences in the flowable filling material, uncertainties in the measured length of the casing. These measurement uncertainties can in combination lead to a greater variance of the produced products. As a result, the overall appearance of the produced goods can vary in shape and weight.

Furthermore, consumers expect an attractive form of sausage-shaped products on which the respective imprints, including various information regarding the sausage-shaped product, are always placed in the same position.

The following description contains specific information pertaining to implementations in the present disclosure. The present application discloses systems and methods for manufacturing sausage-shaped products having a tubular casing using at least one imprint on the tubular casing for controlling the application of a further imprint or rather further imprints, in particular to ensure that the imprint is consistently at the same position relative to the sausage-shaped product.

The objective is achieved by a system for manufacturing sausage-shaped products having a tubular casing provided with at least one imprint according to the present invention as defined in independent claim <NUM> as well as by a method therefor as defined in independent claim <NUM>. Further developments of the present invention are defined in the dependent claims.

According to a first aspect, the system for manufacturing sausage-shaped products having a tubular casing provided with at least one imprint, the system comprising at least one printer, a sealing device, a filling device, a clipping device, a control unit and at least one sensor being operatively connected with the control unit, wherein the at least one printer is configured to apply at least one imprint on a foil being provided for forming the tubular casing, wherein the sealing device is configured to seal the foil at opposing ends in longitudinal direction to form the tubular casing, wherein the filling device is configured to fill the tubular casing with a filling material, wherein the clipping device is configured to set at least one closure means, wherein the at least one sensor is configured to detect the position of an imprint on the tubular casing and at least one further characteristic of the tubular casing or the sausage-shaped product, wherein the control unit is configured to monitor the distance between the imprint and the at least one characteristic detected by the at least one sensor, and wherein a feedback control is implemented in the control unit to adjust the distance between an imprint to be applied on the foil bring provided for forming a tubular casing for a subsequent sausage-shaped product and the at least one further characteristic. According to this, it is ensured that the imprints are positioned at the same location on each sausage-shaped product. Therefore, it helps in producing sausage-shaped products with equal length and similar appearance.

In some embodiments, the at least one further characteristic is a subsequent imprint on the tubular casing of a sausage-shaped product, a closure means, or a rapid decrease/increase in the caliber of the sausage-shaped product. Therefore, different applications of this concept are possible.

In some embodiments, the control unit is configured to control the at least one printer based on the monitored distance between the imprint and the at least one further characteristic detected by the at least one sensor. By doing this, a feedback loop is employed and acts as an integrated automated quality management.

In some embodiments, the sealing device comprises an endless belt, which is guided around two horizontally and perpendicularly to the axis of a filling tube arranged guiding rollers, and which can be heated by means of a heating device. By adding this device, the system can further integrate the production of tubular casings.

In some embodiments, the system further comprises a further printer, which is configured to apply additional information on the foil of the tubular casing. The second printer enables the system to print imprints, additional to the first imprint. This helps in adding additional information on the sausage-shaped product.

In some embodiments, the at least one printer is a thermo-transfer printer. By choosing this kind of printer, the imprint is added in a fast and convenient manner.

In some embodiments, the imprint and the at least one further characteristic are positioned at predefined intervals on the tubular casing, preferably in regular intervals. By doing this, the deviation in the length of the sausage-shaped products is minimized.

In some embodiments, at least one sensor is positioned in flow direction of the tubular casing upstream of the clipping device. With this choice, the sensor can be positioned in the system, therefore being in an integrated position. This can help in fixing the absolute position of the sensor.

In some embodiments, at least one sensor is positioned in flow direction of the tubular casing downstream of the clipping device. With this choice, the sensor can also sense the previously set closing means.

In some embodiments, the at least one sensor is a CCD sensor or an imaging sensor. By doing this, the system is able to further distinguish between different characteristics, such as different imprints.

According to a further aspect, a method for manufacturing sausage-shaped products having a tubular casing provided with at least one imprint, the method comprises the steps of: providing a foil; applying at least one imprint on the foil; sealing the foil at opposing ends in longitudinal direction to form a tubular casing; filling the tubular casing with a filling material; and sealing the filled tubular casing in a clipping device with at least one closure means to form sausage-shaped products; wherein at least one sensor is configured to detect the position of an imprint on the tubular casing and at least one further characteristic of the tubular casing or the sausage-shaped product, wherein a control unit is configured to monitor the distance between the imprint and the at least one characteristic detected by the at least one sensor, and wherein a feedback control is implemented in the control unit to adjust the distance between an imprint to be applied on the foil being provided for forming the tubular casing and at last one characteristic.

In some methods, the at least one further characteristic is a subsequent imprint, the closure means, or a rapid decrease/increase in the caliber of the sausage-shaped product.

According to a further method, when the distance between the imprint and the at least one further characteristic just determined by the control unit deviates from the distance determined between an imprint and a characteristic at the beginning of the process for producing sausage-shaped products by a predetermined value, the position of imprints to be applied on the foil for subsequent sausage-shaped products are adjusted respectively.

In some methods, the predetermined value is in a range of +/- <NUM>% of the value determined by the distance between the imprint and the characteristic at the beginning of the process for producing sausage-shaped products. This allows a control deviation in which the control unit does not intervene.

In some embodiments, the method for manufacturing sausage-shaped products is shut down, when the distance between the imprint and the at least further characteristic just determined by the control unit deviates from the predetermined value by a predetermined over-value. According to this, destruction of components can be avoided in case of malfunctions.

Moreover, in some embodiments, the system can comprise one or several printers. The printer can be of any type capable of applying imprints on a foil. In particular, the printer can be any type of a thermal printer, such as a thermo-transfer printer. The printer can also be an inkjet printer. The printer may be capable of printing colours, black and white prints or imprints that are not visible to the human eye. For example, the printer can print imprints only visible by the usage of UV light.

The system contains a sealing device, which is configured to seal a foil at opposing ends to form a tubular casing and to deliver a tubular casing to the filling device. The sealing device comprises a forming shoulder which can be tubular shaped. The forming shoulder can have a certain outer diameter and an inner bore. The tubular casing is resting on the outer surface of the forming shoulder. The sealing device can be flush connected to the filling device. Additionally, the sealing device can comprise a retention device at one end of the sealing device. The retention device is used for slowing down the pull speed of the tubular casing from the sealing device during filling. In some embodiments, the retention device is a coaxial brake ring mounted on one end of the sealing device. The tubular casing is wrapped around the retention device and stretched in radial direction, since the inner diameter of the tubular casing is in general smaller than the outer diameter of the retention device. This creates friction between the tubular casing and the retention device, effectively slowing down the pull speed during filling.

The filling material can be any type of filling material. In particular, the filling material can be a flowing filling material. The flowable filling material can include crumbs. The filling material can be sausage meat. The filling device fills the filling material into the tubular casing. The filling device comprises a filling pipe having the tubular casing positioned on its outer surface. The filling device can have any form of cross-section, in particular rectangular or circular. In some embodiments, the filling device is tubular shaped. The filling material can be introduced into the filling device at various filling speeds, preferably continuously.

The sausage-shaped products are closed on each end with at least one closure means. The closure means can be any mean capable of closing sausage-shaped products in a plait-like manner. For example, the closure means can be clips applied by a clipping device. The closure means close the open ends of the tubular casing. A displacer unit in the clipping device constricts the free end of the foil and applies at least one clip.

The system also comprises a control unit. The control unit can comprise a processor, an Analog-to-Digital converter (ADC) and a memory. The software for detecting characteristics is stored on the memory. The control unit is connected to the sensor and can also be connected to the printer. The control unit can also be connected to other parts of the system, such as the filling device, the sealing device or the clipping device, via connection means. The control unit processes the measured signals from the sensor. In particular, the control unit can determine the distance between imprints or between characteristics or between characteristics and imprints. This is achieved by taking into account the filling speed, which is considered a known constant and the measured time between imprints or characteristics detected by the sensor. The filling speed can be stored in the memory. The filling speed corresponds to the speed of the beginning of the sausage-shaped product during the filling step. The filling speed is usually measured in kg/s. With the density of the filling material and the cross-sectional area, the movement speed of the sausage-shaped product in production can be determined. With the movement speed and the measured time between two characteristics, the control unit is able to determine a distance. The control unit is then able to adjust the printing of the imprints on the foil, if necessary, by controlling the at least one printer. The process of measuring the distances between characteristics, imprints or combinations thereof and adjusting the imprints printed by the printer results in a self-regulating feedback loop. In particular, the control unit can comprise a feedback control to monitor and/or control the distance between the imprint and the characteristic of the sausage-shaped product. As a result, the system produces sausage-shaped products with smaller deviations in the position of the imprints. Also, the distances measured can be used to regulate the length of the sausage-shaped products.

The sensor can be any type of a sensor. For example, the sensor can be a photoelectric barrier, a CCD sensor, or an imaging sensor. The sensor is capable of measuring differences in the signal induced from sausage-shaped products or sausage-shaped products during the filling step. The sensor can be positioned next to the clipping device or between the clipping device and the filling device. Additionally, the sensor can comprise a light source. The light source is positioned next to the sensor to illuminate the sausage-shaped products. The reflected light from the sausage-shaped products favours the detection of the imprints or the characteristics by the sensor and the control unit.

The sealing device can be a thermal sealing device, which seals opposite edges of a foil together so that the foil forms a tubular casing. The sealing device can also be a sealing device which uses adhesive to glue the opposite edges together. The sealing device can also be a combination of both.

In particular, the control unit and the sensor are configured to detect characteristics of the sausage-shaped product. A characteristic can be an imprint, at least one closure mean or a rapid decrease or a rapid increase in the caliber of the sausage-shaped product. The control unit and the sensor are able to identify these characteristics and determine a length difference between characteristics.

For the production of the first sausage-shaped product, reference distances may be determined. The first reference distance may be the distance between one end of the sausage-shaped product and the imprint. A second reference distance can be the distance between two imprints or between the imprint and the second end of the sausage-shaped product. The reference distances are then used to regulate the distance intervals between the imprints on the foil. By applying imprints on the foil forming the tubular casing, the system is able to determine the length difference between imprints or between characteristics or between characteristics and imprints.

The printer is applying imprints on the foil. The imprints can be of any type, size and colour. For example, the imprints can be logos. Also, the imprints can be dates indicating the minimum shelf life of the product or the date of production. Also, the imprints can be non-visible for the human eye. The imprints can be positioned on any area of the foil. The imprints are positioned at predefined intervals on the foil, preferably in regular intervals.

Further advantages and preferred embodiments of the present invention will be described in the following together with the drawings listed below. The expressions "left", "right", "below" and "above" used in the following description, are referred to the drawings in an alignment such that the reference numbers and the notation of the Figs. used can be read in normal orientation.

<FIG> depicts an isometric side view of a system <NUM> for manufacturing sausage-shaped products <NUM>, like sausages, according to the invention. In the illustrated embodiment, system <NUM> comprises as main components a printing device <NUM>, a sealing device <NUM>, a filling device <NUM>, a clipping device <NUM>, a control unit <NUM> and a sensor <NUM>.

Filling device <NUM> comprises at least one cylindrical filling tube <NUM> for feeding along feeding direction FD filling material <NUM> from a filler (not shown) into a tubular casing <NUM>, located on filling tube <NUM>, as will be explained below. Filling tube <NUM> made of stainless steel extends horizontally from its right end, where it is connected to the not shown filler, and terminates in an open end just in front of clipping device <NUM>.

Clipping device <NUM> comprises two pairs of displacer means not shown, each pair consisting of an upper and a lower displacer element which can be reversibly moved relative to each other in a vertical plane, extending perpendicular to feeding direction FD, for creating a plait-like portion being at least substantially free of filling material <NUM>. The pair of displacer means being arranged downstream to the other pair of displacer means, referred to feeding direction FD, can be reversibly moved at least substantially parallel to the feeding direction FD.

Clipping device <NUM> comprises further a pair of closure tools, also not shown. The pair of closure tools consists of a punch and a die that can be reversibly moved relative to each other in a vertical plane, extending perpendicular to feeding direction FD, between the two pairs of displacer means to close at least one closure means <NUM>, such as a closure clip, on the plait-like portion after the two pairs of displacer means have created the plait-like portion. Above clipping device <NUM> are arranged two supplies <NUM> for closure means <NUM>, e.g. in the form of clip reels, from each of which a clip row or strand can be drawn off and fed to the closure tools.

During operation, a foil supply <NUM> provides a foil <NUM> (not shown) which is fed into printer <NUM> section. Printing device <NUM> consists of two printers <NUM> which can apply imprints <NUM> on foil <NUM>. Foil <NUM> is then forwarded to sealing device <NUM>. Sealing device <NUM> further comprises a shaping device <NUM> in form of a shaping shoulder being arranged around filling tube <NUM>. Further, a supply roll <NUM> is arranged in front of sealing device <NUM> to direct foil <NUM> in the direction of sealing device <NUM>. Downstream of shaping device <NUM>, with respect to filling direction FD, a sealing tool <NUM> is provided. Sealing tool <NUM> consists of an endless belt, which is guided around two horizontally and perpendicularly to the axis of the filling tube <NUM> arranged guiding rollers, and which can be heated by means of a heating device. The lower run of endless belt can be brought into contact with the outer edges of film material superimposed by shaping device <NUM>, and the heat thus transferred welds or seals these outer edges together to form tubular casing <NUM>. Tubular casing <NUM> is then closed on its downstream side with closure means <NUM>. Following that, tubular casing <NUM> is being filled with filling material <NUM> by filling device <NUM>. The intersection between the filled part and the unfilled part is then emptied by a displacer unit (not shown) and then closure means <NUM>, i.e. a clip, is applied and closed. The steps are then repeated to continuously form foil <NUM> into tubular casing <NUM>, first close them at their downstream end, fill them and then close them at their upstream end to form sausage-shaped product <NUM>.

A sensor <NUM> for monitoring imprints <NUM> on foil <NUM> and/or a further characteristic <NUM>, <NUM> of a sausage-shaped product under production is located between clipping device <NUM> and filling device <NUM>. Sensor <NUM> can also be positioned in downstream direction after clipping device <NUM>. In such a case the sensor <NUM> can detect an imprint <NUM> or a further characteristic of the just finished sausage-shaped product <NUM> or the sausage-shaped product <NUM> under production. In the former case, further characteristic <NUM>, <NUM> can be a further imprint <NUM> on tubular casing <NUM> of this sausage-shaped product <NUM>, a closure means <NUM> at the front end or rear end of this product and/or the front or rear end of this product itself. In the latter case, further characteristic <NUM>, <NUM> can be a further imprint <NUM> on tubular casing <NUM> of this sausage-shaped product <NUM>, a closure means <NUM> at the front end of this product and/or the front end of this product itself. Sensor <NUM> is sending information to a control unit <NUM>, which then determines the interval length between imprint <NUM> and another characteristic <NUM>, <NUM>. It then regulates printers <NUM> to adjust imprint <NUM> on foil <NUM> according to the interval. Additionally shown in the illustration is a control interface for adjusting parameters of system <NUM>.

<FIG> depicts an enlarged view of printer <NUM> section of <FIG>. The illustration depicts a foil supply roll <NUM> delivering foil <NUM> to a double printer <NUM> assembly. Foil <NUM> is fed into double printer <NUM> assembly and imprints <NUM> can be applied. Shown printer <NUM> assembly comprises two thermo-transfer printers <NUM>. Foil <NUM> is fed through printer <NUM> section via pulleys <NUM>. Afterwards, foil <NUM> is then fed to sealing device <NUM>.

<FIG> is a schematic view of the interval between imprints <NUM> on sausage-shaped products <NUM>. In this illustration, three sausage-shaped products <NUM> with imprints <NUM> are shown. A distance d1 is the distance between two imprints <NUM> on two sausage-shaped products <NUM>. Sausage shaped products <NUM> comprise tubular casing <NUM> and filling material <NUM>.

<FIG> is a schematic view of the interval between an imprint <NUM> on a sausage-shaped product <NUM> and a characteristic <NUM>, <NUM>. In this illustration, three sausage-shaped products <NUM> with imprints <NUM> are shown. A distance d2 is the distance between imprint <NUM> on sausage-shaped product <NUM> and a plait-like end of sausage-shaped product <NUM>. In this illustration, distance d2 is the distance between the beginning of sausage-shaped product <NUM>, which is a characteristic <NUM>, and imprint <NUM>. However, distance d2 can also be the distance between imprint <NUM> and the end of sausage-shaped product <NUM>.

<FIG> is a schematic illustration depicting control unit <NUM>, sensor <NUM> and clipping device <NUM>. Sensor <NUM> and clipping device <NUM> are connected to control unit <NUM>. Sensor <NUM> controls clipping device <NUM> based on the information of sensor <NUM>. However, clipping device <NUM> can also control the at least one printer <NUM> in system <NUM>. Furthermore, control unit <NUM> can be connected to other parts of the system such as the filling device or the sealing device by connection means <NUM>.

According to a further embodiment, a method for manufacturing sausage-shaped products <NUM> having a tubular casing <NUM> provided with at least one imprint <NUM>, the method comprising the steps of: providing a foil <NUM>, applying at least one imprint <NUM> on the foil <NUM>, sealing the foil <NUM> at opposing ends in longitudinal direction to form a tubular casing <NUM>, filling the tubular casing <NUM> with a filling material <NUM>, and sealing the filled tubular casing <NUM> in a clipping device <NUM> with at least one closure means <NUM> to form sausage-shaped products <NUM>. Further, at least one sensor <NUM> detects the position of an imprint <NUM> on the tubular casing <NUM> and at least one further characteristic <NUM>, <NUM> of the tubular casing <NUM> or the sausage-shaped product <NUM>. The control unit <NUM> monitors the distance d1, d2 between the imprint <NUM> and the at least one characteristic <NUM>, <NUM> detected by the at least one sensor <NUM>. Moreover, a feedback control is implemented in the control unit <NUM> to adjust the distance d1, d2 between an imprint <NUM> to be applied on the foil being provided for forming the tubular casing <NUM> and at least one characteristic <NUM>, <NUM>.

When the distance between the imprint <NUM> and the at least one further characteristic <NUM>, <NUM> just determined by the control unit <NUM> deviates from the distance determined between an imprint <NUM> and a characteristic <NUM>, <NUM> at the beginning of the process for producing sausage-shaped products <NUM> by a predetermined value, the position of imprints <NUM> to be applied on the foil <NUM> for subsequent sausage-shaped products are adjusted respectively. Advantageously, the predetermined value is in a range of +/- <NUM>%, preferably in the range of +/- <NUM>,<NUM>%, further preferably in the range of +/- <NUM>%, more preferably in the range +/-<NUM>,<NUM>% and further more preferably in the range of +/- <NUM>% of the value determined by the distance between the imprint <NUM> and the characteristic <NUM>, <NUM> at the beginning of the process for producing sausage-shaped products <NUM>.

Claim 1:
A system (<NUM>) for manufacturing sausage-shaped products (<NUM>) having a tubular casing (<NUM>) provided with at least one imprint (<NUM>), the system (<NUM>) comprising:
at least one printer (<NUM>), a sealing device (<NUM>), a filling device (<NUM>), a clipping device (<NUM>), a control unit (<NUM>) and at least one sensor (<NUM>) being operatively connected with the control unit (<NUM>);
wherein the at least one printer (<NUM>) is configured to apply at least one imprint (<NUM>) on a foil (<NUM>) being provided for forming the tubular casing (<NUM>);
wherein the sealing device (<NUM>) is configured to seal the foil (<NUM>) at opposing ends in longitudinal direction to form the tubular casing (<NUM>);
wherein the filling device (<NUM>) is configured to fill the tubular casing (<NUM>) with a filling material (<NUM>);
wherein the clipping device (<NUM>) is configured to set at least one closure means (<NUM>);
characterized in that the at least one sensor (<NUM>) is configured to detect the position of an imprint (<NUM>) on the tubular casing (<NUM>) and at least one further characteristic (<NUM>, <NUM>) of the tubular casing (<NUM>) or the sausage-shaped product (<NUM>);
wherein the control unit (<NUM>) is configured to monitor the distance (d1, d2) between the imprint (<NUM>) and the at least one characteristic (<NUM>, <NUM>) detected by the at least one sensor (<NUM>); and
wherein a feedback control is implemented in the control unit (<NUM>) to adjust the distance (d1, d2) between an imprint (<NUM>) to be applied on the foil (<NUM>) being provided for forming a tubular casing (<NUM>) for a subsequent sausage-shaped product (<NUM>) and the at least one further characteristic (<NUM>, <NUM>).