Processing device for processing food

Abstract

The present invention relates to a processing device for foodstuffs, in particular a derinching, defatting and degreasing machine, which can be operated manually by a single operator and which has a restricted area that should not be accessed. It comprises a safety device that can be worn by the operating personnel on a body part that may potentially enter the restricted area when operating the processing device and that includes at least one activation element that influences a local magnetic field, a sensor device for detecting at least one parameter of the local magnetic field in the restricted area, and a control device that is connected to the sensor device and that is designed and configured to output a control signal when the detected parameter deviates from a setpoint value beyond a predetermined threshold, with which a protective measure can be activated.

Description

[0001] The present invention relates to a processing device for food products that can be operated manually by a single operator. This means that the object to be processed, i.e., the food product, is directly engaged and handled by the operator at the processing device.

[0002] Some examples of such processing devices are derinching, defatting, or skinning machines. However, processing devices for skinning food or removing the rind from cheese wheels are also often operated manually.

[0003] Manual operation of such devices inherently poses a risk of injury to the operator, particularly when moving and / or sharp components are involved that can be reached by hands. In devices of the type mentioned above, for example, the portion of food to be removed is placed face down on a worktable and manually pushed forward until it reaches a pulley roller with a specially designed surface. The pulley roller's design grips the food, and its rotation directs it towards a blade that cuts off the portion to be removed.

[0004] It goes without saying that both the traction roller and the blade are potentially dangerous for the operating personnel. The area surrounding these components is therefore a restricted zone and should not be accessed.

[0005] Many manually operated devices incorporate a safety device that the operator wears on a part of their body that could potentially enter the restricted area while operating the device. A simple example of such a safety device is gloves designed to protect the operator's hands.

[0006] Conventional safety devices have the disadvantage that, while they offer some protection when they come into contact with the feed roller and / or the blade of the machining device, a residual risk remains that the safety device could damage the feed roller and / or the blade, or—far worse—that the operating personnel could be injured.

[0007] It is therefore an object of the present invention to create a machining device of the type described above with an improved safety system that, on the one hand, has a higher level of protection and, on the other hand, is easy to implement.

[0008] This problem is solved by a machining device having the features of claim 1.

[0009] According to the invention, the safety device, which is worn by the operator on a body part that could potentially enter the restricted area when operating the processing device, comprises at least one activation element that influences a local magnetic field. Furthermore, a sensor device is provided for detecting at least one parameter of the local magnetic field in the restricted area. The processing device includes a control unit that is connected to the sensor device – wirelessly or via cable – and which is configured and designed to output a control signal when the detected parameter deviates from a target value beyond a predetermined threshold, thereby activating a protective measure.

[0010] The present invention concept is contactless due to the use of at least one activation element that influences the local magnetic field and does not require any wiring of the safety device to other components of the control unit, as is the case, for example, with a safety system with an electrical operating principle, which requires electrical contact with an electrically contacted functional glove for triggering, for example, after damage to a worn non-conductive protective glove. Such wiring restricts the movements and range of action of the operating personnel and can therefore be perceived as disruptive. There is even a risk that the safety device will then not be worn by the operating personnel in practice.

[0011] The control unit detects intrusion into the restricted area in a timely manner by comparing the measured data (actual values) from the sensor device with data interpreted as characteristic of an undisturbed restricted area (target value), thus preventing unintended contact between the safety device and the potentially hazardous components of the machining device. The invention takes advantage of the fact that the properties of the magnetic field in the critical area of ​​the machining device are easily determined, and changes in the magnetic field can therefore be readily detected.

[0012] This local magnetic field is the sum of several components. It originates from a remanent magnetization of the device, which is often rather small but usually unavoidable, as well as from magnetization induced in the device's components, which are usually made of stainless steel, by an external magnetic field (e.g., the Earth's magnetic field). The sum of these two magnetizations generates a stray magnetic field that is superimposed on the external (Earth's) magnetic field. Stray field components generated by moving components of the machining device can cause the magnetic field occurring in the critical area to be non-static, for example, oscillating.

[0013] The magnetic field present in and around the blocking region during operation of the device, without any disturbance to the blocking region, may be complex, but it can be easily determined. If the sensor measures at least one parameter of the local magnetic field (e.g., the field strength) at at least one critical point inside or outside the blocking region, it will detect a specific measurement value or measurement pattern during normal operation of the device. When the activation element influencing the magnetic field approaches the blocking region, this measurement value or pattern is disturbed. The strength of the disturbance is a measure of how close the activation element has come to the blocking region. As soon as the disturbance becomes too large, i.e.,If a deviation – positive or negative – from a setpoint exceeds a predetermined threshold, the control device detects that the restricted area has been violated or is about to be violated and outputs a control signal that can be used to activate a protective measure. The setpoint need not be a static value, but can be a function of time to account for the fact that the local magnetic field can vary even in an undisturbed restricted area.

[0014] In particular, the control device is designed and configured in such a way that the protective measure is automatically activated by the control signal.

[0015] The protective measure can be a visual and / or audible warning signal. It can also be provided that the processing device switches to an emergency mode, in particular that an emergency stop occurs, the roller drive is decoupled, the direction of rotation of the feed roller is reversed, or the blade is retracted, and / or protective shutters are activated. Such shutters can, for example, be quickly moved in front of the blade or swung aside if the operator gets too close.

[0016] At least one parameter of the local magnetic field can be easily detected, particularly continuously. Furthermore, the concept according to the invention is very flexible. By changing the predetermined threshold and / or the setpoint, the blocking range can be modified and adapted to the specific situation. Ultimately, the sensitivity of the safety system can also be adjusted in this way.

[0017] Further embodiments of the invention are specified in the claims, the description and the accompanying drawings.

[0018] According to one embodiment, the restricted area is a danger zone where operating personnel could potentially injure themselves on a component of the processing device. However, it can also be intended that the restricted area is a particularly critical hygienic area or an area requiring special protection for other reasons, into which no access should be permitted.

[0019] The processing device may include a functional component, in particular a rotary component, that is driven to a movement when operating within the restricted area and is controllable by the control unit. The control unit may be configured and designed to decelerate or stop the functional component with the control signal as a protective measure. The processing device may also include a linear movement of a functional component that is controllable by the control unit. For example, a pulling cut of a blade or saw blade, such as in a band saw for cutting meat.

[0020] The sensor device can be positioned in any location. The only requirement is that it is arranged in such a way that a deviation of the measured parameter can be reliably detected. In particular, care should be taken to ensure that no component interfering with the measurement of the parameter is located between the exclusion zone and the sensor device. Furthermore, in many applications, it is advantageous for the sensor device to be located spatially adjacent to the exclusion zone. It is also conceivable that the sensor device is located in or on the functional component. This applies to both functional components that are movable or moving during operation of the machining device and to fixed functional components.

[0021] According to one embodiment, the sensor device is arranged in or below a support surface onto which the food is fed to the functional component. This surface is often made of stainless steel. Surprisingly, however, it has been found that it is nevertheless possible to detect the approach of the activation element to the exclusion zone "through this surface" using the sensor device.

[0022] The sensor system can comprise at least two sensors, each capable of determining at least one parameter of the local magnetic field. Suitable sensors include, for example, Hall effect sensors.

[0023] In this context, it should be mentioned that the parameter can be the magnitude of the magnetic field prevailing at the measurement location, a component of the magnetic field, or the vector of the magnetic field at the measurement location.

[0024] The sensor system can, for example, comprise a line arrangement of several sensors. For instance, the sensor system might be a sensor bar positioned upstream of the restricted area in the working direction. The working direction is, for example, the feed direction of the food during processing, whereby this working direction is essentially determined by the direction of action of the processing device, but also includes other movements and directions. For example, food is guided manually over a processing device multiple times and in varying orientations.

[0025] However, a two-dimensional and / or a three-dimensional arrangement of sensors is also conceivable.

[0026] In principle, it is also possible to provide more than one sensor device.

[0027] The distribution of the sensors can be adapted to the width of the restricted area, for example the width of a blade and / or a pull roller.

[0028] To simplify maintenance and provide protection, the sensor device can be housed in a waterproof enclosure, particularly a sheet metal enclosure, which is attached to a frame or outer casing of the processing device. This ensures not only mechanical protection but also easy cleaning and hygiene. If a detachable mounting, especially a screw connection, is used, the sensor device can be easily replaced. In certain cases, however, the sensor device can also be attached by welding.

[0029] According to another embodiment, the sensor device can be installed inside a hollow train roller. This has the advantage of a space-saving positioning that is also very close to the source of danger.

[0030] According to another embodiment, the safety device is a glove, in particular a pair of gloves. Preferably, the activation element is incorporated into the glove, for example, sewn in. It is also possible, in principle, for the activation element to be provided as a thread or strip that is incorporated (for example, woven) into the gloves. For hygienic purposes and to protect against corrosion, the activation element can be encapsulated in a waterproof manner. In particular, it is provided that at least each finger of the glove is assigned an activation element (e.g., in the area of ​​the fingertips) to ensure maximum safety.

[0031] To increase the sensitivity of the safety device, a magnetic field generation unit can be provided to create a well-defined local magnetic field within the restricted area. For example, one or more coils and / or one or more permanent magnets can be used to generate a specific magnetic field configuration. This field can be designed so that it is easily influenced by the activation element and / or its changes can be measured with exceptional reliability. The magnetic field generation unit allows the restricted area to be defined and adjusted as needed.

[0032] The activation element can include at least one permanent magnet. For example, it includes a neodymium magnet.

[0033] However, it is also possible for the activation element to have soft magnetic or paramagnetic properties. In this case, the activation element can be magnetized by an external field, in particular by the Earth's magnetic field and / or a magnetic field from the magnetic field generating device. The stray field of the magnetized activation element then leads to a disturbance of the "normal" stray field of the overall device during its operation, which can be detected by the sensor device.

[0034] It is also conceivable that the activation element has a locally shielding property against the magnetic field. In that case, the field would weaken in the danger zone as the safety device approaches it. A weakening of the detected magnetic field can also be a deviation that can trigger the output of the control signal.

[0035] To further enhance the safety of the machining device, a release device can be provided to activate the safety device and enable operation of the machining device at the start of operation. For example, the release device comprises at least one release sensor device, which is positioned at a distance from the sensor device and is designed to detect at least one parameter of the local magnetic field within a release zone. The release sensor device is connected to the control unit, which is configured and designed to output a release signal when the detected parameter deviates from a setpoint value below or above a threshold. This release signal enables the machining device to be enabled at the start of operation. The release signal can be generated, for example, by moving the safety device into an area monitored by the release sensor device.The control unit then "knows" that the sensor device is present. For example, the operator first puts on gloves that act as a safety device and are equipped with at least one activation element. The operator then places their hands within range of the release sensor device, which is located, for example, some distance from the restricted area.

[0036] Additional safety is achieved when the sensor device is integrated into the release mechanism. In this embodiment, the control unit can be configured and designed to output a release signal when the detected parameter deviates from a target value below or above a threshold, enabling the machining device to be released at the start of operation. This embodiment also allows for verification of the sensor device's functionality. The machining device is only released once its proper functioning has been confirmed. For this purpose, the operator can sweep the activation element (i.e., a glove) over the sensor device. Only when the control unit receives a signal from at least one sensor that falls within an expected range is the device released for operation.Optionally, the actual field of a glove could also be read in at one of the steps to compensate for differences in different glove sizes or production variations.

[0037] As an additional safety feature, a mechanically activated release device can be provided. For example, the release device can be equipped with a button that must be pressed to register the presence of a hand outside the restricted area.

[0038] A three-stage release mechanism for the machining device is preferred to ensure maximum operator safety. First, the operator puts on gloves, each equipped with at least one activation element. Next, the operator checks whether the sensor system is functioning correctly by passing one of the gloves over it. If all sensors deliver the expected signal, a first release signal is issued. The operator then places both hands within the range of a release device located away from the restricted area. This device registers the presence of both gloves and issues a second release signal. However, the machining device cannot yet be activated. The operator must first activate a mechanical release device. Only after this has been done can the device be put into operation.The mechanical release device can, for example, include at least one button and / or a pedal.

[0039] It may also be possible to specify time intervals at which at least one of the release steps must be repeated. This can serve to verify consistent application (i.e., wearing the gloves).

[0040] The present invention further relates to a method for operating a processing device, in particular according to at least one of the embodiments described above, wherein a protective measure is activated as soon as a change in the local magnetic field is generated by a safety device worn by an operator in a restricted area which is not to be interfered with, and which exceeds or falls below a predetermined threshold value.

[0041] The present invention is described below by way of example with reference to advantageous embodiments and the accompanying drawings. These show: Fig. 1 a schematic side view of an embodiment of the machining device according to the invention, Fig. 2 a safety device designed as a glove, Fig. 3 and Fig. 4 an embodiment of the machining device according to the invention in a top view, Fig. 5 a side view of an embodiment of the machining device according to the invention, and Fig. 6 an enlargement of an embodiment of a release device.

[0042] Fig. Figure 1 schematically shows a derinding machine 10 with a blade 12, which is used to separate a rind from a food product 14.

[0043] The food product 14 is manually fed via a worktable 16 in a feed direction V towards a counterclockwise rotating pull roller 18. As soon as the food product 14 comes into contact with the surface of the pull roller 18, the roller's surface design engages the product 14 and pulls it further to the left, so that the product 14 comes into contact with the blade 12. By pulling the food product 14 to the left, the blade 12 progressively cuts off a portion of the product 14.

[0044] Both the rotating pull roller 18 and the static blade 12 pose a danger to a person operating the machine 10 if they enter a danger zone G with their hands holding the product 14.

[0045] The derinding machine 10 described above is representative of a large number of processing machines in the food industry that have areas potentially hazardous to operating personnel. Many machines also have areas where, for hygienic or other reasons, certain parts must remain untouched by operating personnel.

[0046] To detect impending interference in area G and to take appropriate countermeasures in a timely manner, the machine 10 is equipped with a sensor device 20, which is designed as a type of sensor bar. The sensor bar 20 comprises a linear arrangement of multiple individual magnetic field sensors, for example, Hall sensors. The sensor bar 20 extends in a direction perpendicular to the feed direction V and, viewed from this perspective, is located in front of the feed roller 18. It is understood that the number of sensors used and their arrangement can be adapted to the specific requirements. Multiple sensor devices 20 can also be provided. The sensors can also be distributed over a surface or arranged in a three-dimensional configuration.

[0047] The sensors of the sensor device 20 measure data during operation of the machine 10 that are characteristic of a combination of the Earth's magnetic field prevailing at the location and the stray field generated by the machine 10. Since slight variations in the Earth's magnetic field and / or variations due to moving parts of the machine 10, in particular the traction roller 18, cause a certain oscillation of the local magnetic field detected by the sensors of the device 20, it may be provided that a learning process and / or a calibration process is first used to determine the range of measurement data that indicates a characteristic state of the machine during operation but without the presence of the food product or the operating personnel.

[0048] The person operating the machine 10 typically wears gloves 22 for hygienic reasons when feeding the food product 14, even with conventional machines. According to the invention, activation elements 24 are incorporated into these gloves 22 or into separate overgloves. In principle, it is possible to manufacture the gloves 22 section by section from materials that influence the magnetic field. For example, they can be made at least partially of hard and / or soft magnetic material. According to one embodiment, threads of such material can be incorporated into woven overgloves. However, it is also possible to provide small activation elements 24 (e.g., magnets) locally, particularly in the area of ​​the fingertips (see figure). Fig. 2) Due to the magnetic properties of the gloves 22, which are imparted to them by the activation elements 24, the magnetic field in their environment changes, whether due to permanent magnetic magnetization (especially in the case of a hard magnetic material) and / or due to a stray field generated by induced magnetization (especially in the case of a soft magnetic material).

[0049] During the feeding of the food product 14, the gloves 22 move closer and closer to the sensor device 20, causing a change in the local magnetic field. The measurement data acquired by the device 20 therefore detect a deviation from the normal state. As soon as the deviation of the measured magnetic field parameter exceeds a certain threshold, a control signal is issued, triggering acoustic and / or visual warning signals. Additionally or alternatively, the feed roller 18 can be braked or brought to a complete stop. Since such a reaction can occur very quickly, the operating personnel are effectively protected from injury. A further advantage is that the danger zone G can be set and adjusted as needed by selecting a suitable threshold. In many cases, the position of the device 20 does not even need to be changed to adjust the danger zone G.

[0050] A safety system of the type described above is very reliable, cost-effective, and virtually maintenance-free, as it requires no mechanically moving components. Existing systems can be easily retrofitted with this system.

[0051] It is also possible, when intervening in the danger zone G, to cover the potentially dangerous blade 12 (e.g. by suitable covers) or to swivel or withdraw it from the danger zone.

[0052] Due to the vector nature of magnetic fields, disturbances not only lead to a change in the local field strength but also to a change in the geometry of the field. Therefore, even small disturbances can lead to significant changes and deviations in the local field that are easily detectable. For example, a specific magnetization of the activation elements 24 may be provided, such that the gloves 22 generate a complex magnetic field. If the gloves approach the sensor device too closely, this field might produce increased readings for some sensors and decreased readings for others. A disturbance caused by the gloves 22 would thus have a characteristic "signature" that is recognizably different from magnetic field changes that are not critical for the operation of the machine 10.

[0053] An additional measure can be the provision of a magnetic field generation device that produces a well-defined magnetic field in the relevant area, the disturbance of which can be measured particularly easily. For example, a magnetic field can be provided that is oriented perpendicular to the measuring direction of the sensors. The sensors are therefore not normally affected by this field. However, if a magnetizable object, such as a glove with soft magnetic activation elements, enters the area of ​​the generated magnetic field, it becomes magnetized, and the stray field of this magnetization can be detected by the sensors.

[0054] Fig. Figure 3 shows a top view of an embodiment of the derinching machine 10 with several separate sensor devices 20, each of which can have one or more sensors. To begin operation of the machine 10, the functionality of the safety-relevant components must first be checked. For this purpose, the operator first runs a glove 22 over the sensor devices 20. If the control unit of the sensor devices 20 (not shown) detects that all sensor devices 20 are delivering a signal that is above a certain setpoint value, and thus recognizes that they are all functioning correctly, an initial enable signal is issued.

[0055] To ensure that the person removes their hands from the danger zone G, they must now bring both hands close to a release device 26. The release device 26 comprises two components located away from the danger zone G and on either side of the work surface of the worktable 14. Fig. Figure 4 merely shows that the operator's right hand is located there. As soon as the left hand is also in the area of ​​the left component of the release device 26, a second release signal is issued, because the control unit now "knows" that the operator's hands are no longer near the danger zone G.

[0056] Once the first and second release signals are received, machine 10 can begin operating. An additional, mechanically operated release device may be provided, allowing the operator to manually release the operation of the derinching machine 10.

[0057] Fig. Figure 5 shows a side view of the machine 10, so that it can be seen that the release device 26 has planar components to which or near which the respective hand must be brought in order to generate the second release signal.

[0058] Fig. Figure 6 shows an embodiment of the release device 26 in which individual sensor fields 28 are provided. To generate the second release signal, the operator must bring their fingertips with the activation elements 24 provided therein into close proximity to the sensor fields 28. This further increases the safety of the machine 10. Reference symbol list 10 Derinching machine 12 blades 14 Food product 16 Work table 18 Pulling roller 20 sensor units 22 Glove 24 Activation element 26 Release device 28 sensor fields V Feed direction Danger area

Claims

A processing device for processing foodstuffs, in particular a derinding, defleshing and degreasing machine, which can be operated manually by an operator and which has a restricted area (G) which should not be accessed, comprising a safety device (22) which can be worn by the operator on a part of the body that may potentially enter the restricted area (G) when operating the processing device and which comprises at least one activation element (24) which influences a local magnetic field, a sensor device (20) for detecting at least one parameter of the local magnetic field in the restricted area (G), and a control device which is connected to the sensor device (20) and which is configured and designed to output a control signal when the detected parameter deviates from a setpoint value beyond a predetermined threshold, with which a protective measure can be activated. Processing device according to claim 1, wherein the restricted area (G) is a danger zone in which the operating personnel may potentially injure themselves on a component of the processing device. Machining device according to claim 1 or 2, wherein the machining device comprises a functional component (18), in particular a rotating functional component (18), which is driven to a movement in the restricted area (G) during its operation and which is controllable by the control device, wherein the control device is configured and designed to decelerate or stop the functional component (18) with the control signal. Processing device according to at least one of the preceding claims, wherein the sensor device (20) is arranged in or on the functional component. Processing device according to at least one of the preceding claims, wherein the sensor device (20) comprises at least two sensors, with which at least one parameter of the local magnetic field can be determined. Machining device according to claim 5, wherein the sensor device (20) comprises a sensor bar which is positioned upstream of the blocking area (G) in the working direction. Machining device according to at least one of the preceding claims, wherein the sensor device (20) is arranged in a waterproof housing, in particular a sheet metal housing, which is attached to a frame or an outer housing of the machining device, in particular by means of a welded or screwed connection. Processing device according to at least one of the preceding claims, wherein the safety device (22) comprises a glove, in particular a pair of gloves. Machining device according to at least one of the preceding claims, wherein a magnetic field generation device is provided with which a well-defined local magnetic field can be generated in the restricted area (G). Machining device according to at least one of the preceding claims, wherein the activation element (24) comprises at least one permanent magnet. Machining device according to at least one of the preceding claims, wherein the activation element (24) has soft magnetic or paramagnetic properties. Processing device according to at least one of the preceding claims, wherein a release device (26) is provided which can be activated with which the safety device (22) can be activated to release the operation of the processing device at the start of operation. Machining device according to at least one of the preceding claims, wherein the release device (26) comprises at least one release sensor device which is arranged spaced apart from the sensor device (20) and which is provided for detecting at least one parameter of the local magnetic field in a release area, wherein the release sensor device is connected to the control device, and wherein the control device is configured and designed to output a release signal when the detected parameter deviates from a setpoint value beyond a threshold value, with which the machining device can be released at the start of operation. Machining device according to claim 13, wherein the sensor device (20) is part of the release device (26) and wherein the control device is configured and designed to output a release signal when the detected parameter deviates from a setpoint value below and / or above a threshold value, with which the machining device can be released at the start of operation. Machining device according to at least one of the preceding claims, wherein the release device (26) comprises at least one mechanically activatable release device (26). Method for operating a processing device for processing foodstuffs, in particular a derinding, defleshing and degreasing machine, in particular according to at least one of the preceding claims, wherein a protective measure is activated as soon as a change in the local magnetic field exceeding a predetermined threshold value is generated by a safety device (22) worn by an operating person in a restricted area (G) which is not to be interfered with.

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