Abstract:
The invention relates to an animal body measuring apparatus, designed to individually detect features of slaughtered animal bodies that are conveyable in a row at a distance from each other and along a path, in particular poultry bodies, which measuring apparatus comprises at least one sensor, a measurement passage space for conveying the animal bodies through along a measurement passage path, on which at least one said sensor is arranged, and a holding means. The holding means comprises a movement means, by means of which said sensor, by moving the sensor back and forth, is displaceable between the measurement position lying within the measurement passage space and an outer position permitting free passage of the animal bodies, which outer position as such lies completely outside the measurement passage space. A processing apparatus for removing the meat of slaughtered animal bodies, in particular gutted bodies of poultry whose extremities have been detached, comprises at least one measuring apparatus of the stated design.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to PCT/EP2012/073450, having a filing date of Nov. 23, 2012 which claims priority to European Patent Application 11191797.7 having a filing date of Dec. 2, 2011, the entire contents of each of which are hereby incorporated by reference. 
     
    
     FIELD OF TECHNOLOGY 
       [0002]    The following relates to an animal body measuring apparatus designed to individually detect features of slaughtered animal bodies that are conveyable in a row at a distance from each other and along a path, in particular poultry bodies to be filleted, said measuring apparatus comprising at least one sensor designed to measure at least one feature of the animal body, a measurement passage space for conveying the animal bodies through along the measurement passage path, on which at least one said sensor is arranged for measurement during conveyance, and a holding means, which holds said sensor in a position lying within the measurement passage space. The invention also refers to a processing apparatus which is equipped with at least one said measuring apparatus. 
       BACKGROUND 
       [0003]    Said measuring apparatus is usually part of a processing apparatus for processing slaughtered animal bodies, with animal bodies understood to include animal body parts as well. The processing apparatus is particularly designed for processing poultry, particularly filleting breast caps or front halves. The apparatus, particularly for removing the meat from gutted bodies of slaughtered poultry without extremities, comprises processing tools arranged in a processing line, a driven conveyor with holding apparatuses arranged on it in a row along the processing line to transport animal bodies that are supported there, particularly saddled poultry bodies and, to let these pass the processing tools, at least one measuring apparatus emitting measurement signals for recording individual body features of the animal bodies, and a control device, which receives the measurement signals, for controlling the operation of the processing tools. 
         [0004]    A generic processing apparatus with measuring apparatuses is known, for example, from DE 198 48 498 A1 and described there. The holding apparatuses are arranged along the processing line on the conveyor, which is usually rotatingly equipped with an upper and lower run. In most cases, the holding apparatus is provided as a saddle-like support body, as known and described, for example, in DE 39 18 345 A1. The measuring apparatus constitutes a measurement station in the processing apparatus. The sensor records specific data which concern individual features of the animal body to be processed. For example, size, geometry and/or position in space are determined. The body joints of a poultry body, specifically the two articulation points of the shoulder, are particularly suited as measurement points which are oriented toward the front in the conveyor&#39;s direction of transport and are detected by dedicated sensors, which are formed by measuring elements which are deflectable, particularly when subject to restoring force, such as measuring tags. In particular, a measuring apparatus is also envisaged which measures the thickness, i.e. a cross dimension of the animal body to be processed, and works with measuring elements under restoring force, for example in the form of a pair of flap-like pivot elements. 
         [0005]    The known measuring apparatuses, which are equipped with the pivoting sensors, can only record poultry bodies conveyed in a row which are sufficiently spaced during transport and/or the conveyance. The throughput is limited due to minimum distances to be maintained. The pivot-mounted sensors disengage from the holding apparatus and/or the animal body supported thereon only after its passage through the measuring apparatus, and they require time and space between the holding apparatuses to assume a defined initial position, specifically a standard position, for the start of the following measurement. 
       SUMMARY 
       [0006]    Thus, the invention is based on the objects to create a measuring apparatus which is operable significantly faster for individual measurement of animal bodies conveyed in a row. The measurement operation is also to be improved where necessary with respect to protection of the sensor and/or the sensor improved for measurement. 
         [0007]    The objects are achieved in conjunction with the features of the measuring apparatus mentioned hereinbefore by the holding apparatuses comprising a movement means with which said sensor is adjustable by movement back and forth between the measurement position lying within the measurement passage space and an outer position permitting free passage of the animal bodies, the outer position as such lying completely outside the measurement passage space. In the outer position, a cross-sectional overlap of the sensor cannot occur with the animal body to be measured in the measurement passage space. A processing apparatus mentioned hereinbefore has at least one said measuring apparatus according to the invention. This particularly increases throughput, and measures and possibilities for increasing throughput are improved. 
         [0008]    The invention selectively effects the measurement position on the one hand and the outer position of the sensor on the other. In the measurement position, the sensor is located within the measurement passage and/or the associated passage path, namely in a passage cross-section which is passed by animal bodies to measure. In the measurement position, measurement of the animal body takes place in such a way that using the sensor at a particular position or even in a particular area of the animal body a particular position, dimension or even a measurement recording a representative condition is attained. The sensor can be constituted by any suitable measuring apparatus which works with tactile contact or with non-tactile contact, particularly which is optical or otherwise effected with measurement shafts and/or beams. According to the invention, the sensor is located in its outer position, which is raised compared with the measurement position triggered, completely outside the measurement passage space. Thus in the raised/outer position, it comes to lie with the animal body to measure, completely free of cross-sectional overlap, i.e. outside the cross-section in which the animal body to be measured passes the passage space. The outer position enables the sensor to be set in a position, in particular in an initial or normal position, without influence from the animal body passing through the measurement passage, said position defining or preparing the start of measurement for the next measurement. This start of measurement can consequently be planned and set nearly independently, i.e. without limitation from the time interval of conveyance of animal bodies to measure one after the other. Moreover, one possibly achieves improved use of calculation time for a control/evaluation unit processing the measurement result. Is also achieved that the sensor is not constantly in one correspondence position corresponding to the measurement position while the animal body passes, but is instead held in the outer position at least for the most part at time without measurement. These measures also result in protection of the animal body to be measured during passage through the measurement passage of the measuring apparatus. In a processing apparatus according to the invention in which at least one measuring apparatus according to the invention is situated, the throughput can be increased considerably, largely independent of the processes for measurement. 
         [0009]    According to the invention, the holding means of the sensor comprises a movement means which moves the sensor back and forth in such a way that it alternately assumes the measurement position or the outer position. Many designs are possible for such a movement means. The displacement of movement means can advantageously be achieved by a pivot mechanism in which the sensor is pivotable back and forth on a pivot axis extending particularly in the direction of the measurement passage path. Advantageously, the sensor can be pivotably hinged via a lever-like or arm-like element, for example like a piston or crank-like element, which is operated with a controlled drive, advantageously a pneumatic one. 
         [0010]    It has been proven to be particularly advantageous to connect a sensor able to pivot on a pivot axis to move out and a holding element stationary in the apparatus with a control element, the length of which can be changed by control, to effect the pivoting movement of the sensor for moving out or moving in according to the measure of the change in length. The length-adjustable control element is advantageously a controllable pneumatic cylinder. A preferred embodiment is constituted where the length-adjustable control element and the stationary holding element are pivot-mounted on a shared axis, specifically on a measurement pivot axis, to perform a measuring pivot movement for measurement on the animal body. 
         [0011]    The movement means can also comprise a cam for controlling the displacement of the sensor between a measurement position and an outer position. The cam can be a sliding block guide for a control path, for example. The drive can be implemented by active elements, such as by a pneumatic system or passive means, particularly by levers or rod guides, which are preferably connected to drive, conveyance and/or control elements of a processing apparatus and thus are operable and/or controllable with these. 
         [0012]    An optical sensor can be provided, for example, which works without contact, and which, in its measurement position, records a measurement value at an assigned point and is designed to record the quantity to measure without contact with the animal body. 
         [0013]    A particularly advantageous design is constituted where the movement means comprises a control means which effects a time sequence, said control means being designed such that it controls movement of the sensor first in its measurement position and after completion of the measurement in its outer position still during the passage of the measured animal body. The control means can comprise a computer-controlled and/or mechanical control. 
         [0014]    A normal position which defines the start of each measurement advantageously belongs to the outer position. Depending on the time required, such an initial position can be established particularly in the time directly after performing the measurement and in any case at the time when the animal body to be measured has not yet completely passed the sensor in the measurement passage, in particular only to a small extent as well. This is particularly important for designs in which the sensor is arranged and configured on the measurement passage path so that it touches the animal body to be measured and is to be moved out of this position again. 
         [0015]    Preferably at least one said sensor is designed in an in principle known manner such that it is pivotable in its measurement position, particularly against restoring force, coming to rest on each animal body to be measured, wherein it produces a measurement result in proportion to the measurement pivot deflection from a normal position and in the outer position achieves the normal position by action of a restoring force. In such a case, the outer position comprises a defined normal position between two sequential measurements. However, a normal position defining the start of measurement can also be set in other cases in the sensor&#39;s outer position, i.e. generally in cases in which the sensor with its position set in the outer position, maintaining it in this respect, is brought to the measurement position to perform the measurement by starting in the latter position. 
         [0016]    A sensor which, particularly against restoring force, comes to rest by pivoting in its measurement position on each animal body to measure is advantageous as a measurement tag, known in itself, or designed as another rigid pivot element which, upon contacting a point of the poultry body to measure, deflects by rotation to generate a measurement. 
         [0017]    Advantageously, a measuring apparatus is designed and arranged with a deflectable sensor for recording the position of at least one pre-aligned body point of conveyed animal bodies in the processing line of a processing apparatus. In this case and generally in processing apparatus according to the invention the measurement signal acquired during the conveyance is available to a control device of the processing apparatus to control the operation of processing tools, particularly separation tools. In particular, sensors, formed by measuring tags or the like, are usually arranged in pairs to identify and/or record the shoulder body joints of poultry bodies to be measured and/or processed. Such sensors are installed offset, corresponding to the interval of the body joints. 
         [0018]    A measuring apparatus according to the invention is also configurable to record a lateral dimension, in particular the maximum thickness of each animal body. Such a measuring apparatus comprises in an in principle known manner, for example, two sensors or measuring elements arranged in a plane and forming, in the manner of a two-leaf swinging door, a measurement passage or a passage capable of opening, particularly against restoring force, for body measurement. Such a measuring apparatus also supplies control signals for the control device of the processing apparatus to control one or more processing/separation apparatuses or other parts or units along the processing line. 
         [0019]    A particular advantage of a processing apparatus according to the invention is that the movement means of the measuring apparatus can comprise a means of control or setting by which the time in which the sensor is in its outer position is set according to the requirement of a desired time interval between two sequential holding apparatuses during conveyance. The sequence and/or speed of the change of the sensor&#39;s displacement between its measurement position and its outer position can be set depending on the desired time interval between two sequential holding apparatuses. This setting is not impaired or hindered by the conveying distance of the holding apparatuses, which are the same in most cases and also equally spaced, i.e. in particular not by time required for measurement, for example by running a computer control program of the measuring apparatus and/or a control device of the processing apparatus for measurement processing and/or evaluation. 
         [0020]    A particular advantage of the processing apparatus according to the invention is that the throughput can still be increased even with relatively low conveying speed or conveying speed limited by design and/or operating parameters of the processing apparatus. Thus the control means of the measuring apparatus can be configured and set such that the short time for measurement between two sequential holding apparatuses can be matched. At constant conveying speed, these can be arranged with the same spatial distance and thus in a correspondingly reduced time interval by reducing the spatial distance, with the time between two initial/normal positions able to be selected according to the invention on the scale of the timed spacing of the holding apparatuses or less. The (equal) interval of the holding apparatuses can be reduced to a generally small size which determines and thus significantly increases the throughput of the processing apparatus and/or the system operated with it. 
         [0021]    Dependent claims are based on the embodiments of the invention described and on other practical and advantageous embodiments. Only particularly practical and advantageous forms and options are further detailed based on the following description of the exemplary embodiments shown in the schematic drawing. Each individual or detailed design described in an exemplary embodiment is to be understood as an independent detail example for other implementations or designs in the scope of the invention which are not described or are described only in part. 
     
    
     
       BRIEF DESCRIPTION 
         [0022]    The drawings show in 
           [0023]      FIG. 1  a top view of a section of the lower run of a processing apparatus according to the invention equipped with a measuring apparatus according to the invention, 
           [0024]      FIGS. 2A and 2B  a side view and top view of parts of a measuring apparatus according to the invention which is arranged on a conveyor section conveying animal bodies by means of holding apparatuses, 
           [0025]      FIGS. 3A and 3B  a frontal view and side view of the measuring apparatus of  FIG. 2  in a raised condition, and 
           [0026]      FIGS. 4A and 4B  a frontal view and side view of the measuring apparatus of  FIG. 2  in a moved-in condition. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]      FIG. 1  shows a section of a known processing apparatus  7 . The example is a poultry handling and processing apparatus for separating the fillets of gutted bodies of poultry whose extremities have been detached. Such a processing apparatus comprises a plurality of stations which are arranged along a conveyor section which has an upper and lower run and belongs to a processing line  70 . Parts, specifically and in particular processing tools of the stations, are operated using a computerised control device  8 , which produces the control signals B 1 , . . . , Bn supplied to the stations in particular according to the requirements of measurement/control signals M 1  . . . Mn. 
         [0028]      FIG. 1  shows only two processing stations  73 ,  74  arranged on the lower run, namely a first scraping apparatus  731  and a second scraping apparatus  741 , which is arranged after the first one in the direction of conveyance F, with associated processing tools. 
         [0029]    The lower run section shown is also equipped with two measuring apparatuses  1 ;  11 ,  12  which are arranged upstream of the processing stations  73 ,  74  in the processing line  70 . As will be described in more detail, the measuring apparatuses  1  are designed according to the invention. In the processing apparatus  7  according to the invention according to the exemplary embodiment of  FIG. 1 , the measuring apparatus  11  is assigned to the processing station  73 , while the measuring apparatus  12  is assigned to the processing station  74 . The measuring apparatus  12  is arranged between the measuring apparatus  11  and the processing station  73 . 
         [0030]    The processing apparatus  7  comprises a frame or housing  71  on which the processing tools of the individual stations are arranged and attached. A conveyor device which is not shown has a continuously rotating conveyor which constitutes the upper and lower run. Known holding apparatuses  77  are attached on the conveyor at equal distances. Parts of the holding apparatus  77  are seen in  FIG. 2B to 4B . It comprises a support body  772  forming a saddle and a base plate bearing the support body, attached to the conveyor, and a clamping device which is not shown. The holding apparatus  77  is located on the lower run in position with the support body  772  pointing downward. 
         [0031]    Parts of the poultry body  90  are the sternum plate  91 , the sternum  92 , the coracoids  93  and the wishbone  94 . Body joints  96 , on which shoulder blades  95  are also seated, connect the wishbone  94  with the coracoids  93 . 
         [0032]    The poultry body  90  rests on the holding apparatus  77 , with the sternum plate  91  coming to lie on the saddle support surface of the support body  772 , and is secured by means of the clamping device, which comprises a clamping lever working against the sternum plate  91  and/or the support surface of the support body  772 . A suitable clamping/control mechanism, which is not shown and which comprises a trigger element  774  projecting on the base plate  771 , opens and closes the clamping device for loading and unloading. Associated constructions and mechanisms, which can be quite varied, are common and known. 
         [0033]    The measuring apparatus  11  is described in more detail below based on  FIG. 2A to 4B . 
         [0034]    The measuring apparatus  11  is designed to detect body joints  96  of a passing animal body  9 , specifically a poultry body  90 . The measurement takes place in particular to record the positions of the body joints  96  for each individual poultry body  90 . Information on the body dimensions can also be obtained. 
         [0035]    As can be seen in  FIG. 2A to 4B , according to the exemplary embodiment, the measuring apparatus  11  comprises two sensors  2 , specifically a first pivot element  21  for measurement and a second pivot element  22  for measurement. A part of the measuring apparatus  11  forming the holding means  4  bears the two pivot elements  21 ,  22  for measurement. The holding means  4  comprises a plurality of parts, specifically a console or a bearing body  41 , holding elements  42  supported thereon, specifically holding arms  421 , a bearing element  43  attached on an associated holding element  421  in each case, specifically a bearing plate  431  and, between the pivot element  21 ,  22  for measurement and the bearing element  43  in each case, a movement means  5 . The bearing body  41  can be a console or holding base, for example, which is constituted in particular by a frame, a housing and a bearing part  410  of the measuring apparatus  11 . For example, a part of a housing wall of the processing apparatus  7  can form the bearing body  41 , as seen in  FIG. 1 . 
         [0036]    As shown in  FIG. 3A to 4B  with dash-dotted lines, the measuring apparatus  11  comprises a passage space  3  and a passage path  31 . The passage path  31  is the path which the measurement object, specifically the animal body  9  or the poultry body  90 , must travel to pass the at least one sensor  2  or the pivot elements  21 ,  22  for measurement which are arranged on the passage path  31 . Accordingly, the passage space  3  is the space in which the at least one sensor  2  and/or the pivot elements  21 ,  22  for measurement is enclosed spatially and physically for measurement and which is envisaged and designed for crossing the animal body  9  and/or the poultry body  90 . 
         [0037]    In the exemplary embodiment, the pivot elements  21 ,  22  for measurement are arranged at a distance  20  transverse to the measurement passage path  31 , which corresponds to the spacing of the body joints  96  of the poultry body  90 . The transverse distance  20  is configured so that the body joints  96  of all poultry bodies  90  to be measured are recorded by touching for measurement. As is generally known, for this purpose the pivot elements  21 ,  22  for measurement are constituted by rigid measuring tags which have a sufficient width transverse to the measurement passage path  31  so that they protrude into the path of each body joint  96  for measurement. This arrangement is shown in  FIGS. 4A and 4B . Each pivot element  21 ,  22  for measurement is attached and rotationally fixed on the associated holding element  42 , which is supported on the bearing body  41  and can pivot on a pivot axis  40  for measurement. Each pivot element  21 ,  22  for measurement is dimensioned with length such that its free end is in the path of the body joints  96 . The pivot elements  21 ,  22  for measurement are arranged offset in the moving direction of conveyance F of the measurement object or along the measurement path  31 . They can also lie next to each other at the same path position. 
         [0038]    The measurement arrangement and function of the pivot elements  21 ,  22  for measurement are known per se. In  FIG. 4B , the right body joint  96  is directly before measurement contact with the pivot element  21  for measurement, which pivots by a measurement angle W of approximately 25°, for example, to measure the body joint  96 , doing so by turning adjustment of the holding element  42  on the measurement pivot axis  40 . This measurement angle W, which can also be significantly less than 25°, is recorded with a measurement means  32  and converted to a corresponding measurement signal M 1 . To produce a measurement signal M 2  in the same way, the other body joint  96  on the left is measured with the second pivot element  22  for measurement, which is located at a distance after the first pivot element  21  for measurement along the passage path  31 . The resulting combined measurement signal can also be constituted from M 1  and M 2 . 
         [0039]    The positions of the pivot elements  21 ,  22  for measurement shown in  FIGS. 1 ,  2 A,  2 B,  4 A and  4 B belong to measurement positions I of the pivot elements  21 ,  22  for measurement. The measurement position I is generally defined as a position in which the sensor  2  spatially overlaps with parts of the animal body  9  to be measured in the measurement passage space  3  and/or in the measurement passage path  31  before its measuring contact and during its measuring contact with the animal body point to measure. 
         [0040]    In  FIGS. 3A and 3B , the measuring apparatus  1  is shown with positions of the pivot elements  21 ,  22  for measurement which ensure free passage of the poultry bodies  90 . The positions shown for the pivot elements  21 ,  22  for measurement are outer positions II. The sensor  2  is located completely outside the measurement passage space  3  in each outer position. 
         [0041]    In the exemplary embodiment, the movement means  5  in each case with an associated bearing element  43  and connected to the pivot elements  21  or  22  for measurement is a length-adjustable control element  52 , namely a pneumatic cylinder  521 , which constitutes part of a pivot mechanism  51  and controls the pivot element  21 ,  22  for measurement with pivoting movement on a pivot axis  50  for moving out. The pivot axis  50  extends in the direction of the measurement passage  31 . As is particularly clear when comparing  FIG. 3A ,  3 B and  FIG. 4A ,  4 B, the movement means  5  enables back-and-forth motion of the associated pivot element  21  or  22  for measurement between the measurement position I and the outer position II. 
         [0042]    The frequency and/or the sequence of the back-and-forth motion of the at least one sensor  2  or in the exemplary embodiment of the pivot elements  21 ,  22  for measurement can be configured in many ways as required. Thus the movement means  5  can be provided with a motion drive, in the example with a controlled pneumatic drive, which controls the motion in time intervals which can be defined or set in a fixed manner. It is particularly practical and advantageous to control or arrange the movement between measurement position I and the outer position II as required or depending on the passage speed of the animal body  9  through the measurement passage space  3  and/or depending on the spatial interval with which the animal bodies  9  to measure follow one another. 
         [0043]    In the exemplary embodiment of  FIG. 1 , the measuring apparatus  11  comprises a control means  6 , which in each case controls movement of the pivot elements  21 ,  22  for measurement in measurement position I and after completion of the measurement in the outer position (II) during the passage of the measured poultry body ( 90 ). Such a control can be implemented with any conventional pneumatic control, for example as shown in  FIG. 2B  with the reference number  522  and associated lines  523 . Instead of a pneumatic control, any other suitable motion control can be used for the drive and movement sequence. In particular a cam control, which is not shown, can be connected with elements of the conveyor of the processing apparatus  7  to effect movement drive. 
         [0044]    The control means  6  can also be constituted by a control part of the control device  8 , as shown in  FIG. 1  with control connection S. 
         [0045]    In the exemplary embodiment according to  FIG. 1 , it is particularly advantageous that the measurements can be performed on poultry bodies  90  which follow one another with even very small spacing. This succeeds by the pivot elements  21 ,  22  for measurement being able to execute a sudden controlled movement out of the measurement passage space into the V-shaped position shown in  FIG. 3A  in each case after conclusion of the measuring procedure, for example after a measurement and possible subsequent deflection of about 25°. Moving up to the outer position II achieves an initial or normal position III for measurement at the same time. This position is defined by at least one sensor  2  and/or the pivot elements  21 ,  22  for measurement not only reaching the outer position in which the measurement passage is cleared for the animal body  9  measured or to be measured but also a defined position for starting the next measurement. This position is assumed in  FIG. 3A  and  FIG. 4B . In this respect it is independent of the pivot position of the pivot elements  21 ,  22  for measurement about the pivot axes  50  to move out as long as the pivot elements  21 ,  22  for measurement do not touch or are not in active measuring contact with the animal body  9 . In the exemplary embodiment, it is important that the measurement deflection on the pivot axis  40  for measurement is restored in each case. Restoring the pivot deflection can be done by a restoring device  33  producing a restoring force, for example, which produces a restoring force during deflection or at a point of deflection, which returns the pivot element  21 ,  22  for measurement to the normal or zero position. 
         [0046]    An example of an arrangement with a restoring device  33  is shown in  FIGS. 2A and 2B . In each case, the holding element is connected in a rotationally fixed manner with an axial element  34 , which in turn is connected in a rotationally fixed manner with an arm element  333 . A tension spring  331  holds the arm element  333  in the outer and normal position II, III against a stationary, fixed stop  332 . For example, the measurement deflection W can be converted to a signal supplied to the measurement means  32  via the axial element  34  using a converter such as an angle encoder. 
         [0047]    The relatively small space described between two sequential animal bodies  9  is achieved in the exemplary embodiment of the processing apparatus  7  by the holding apparatuses  77  on the conveyor being arranged with corresponding small, equal spacing. This achieves a significant increase of the throughput. With particularly constant conveying speed, the timing of the control means  6  can then be set or configured as required by the chosen small space between the holding apparatuses  77 . 
         [0048]    The first measuring apparatus  11 , which detects the body joints  96 , controls the scraping tools of the scraping device  731  using the control device  8 , for example to space it as required by the individual distances of the body joints  96 . 
         [0049]    As shown in  FIG. 1 , the second measuring apparatus  12  comprises two sensors  2 , specifically pivot elements  23 ,  24  for measurement, which are constituted in symmetrical arrangement by flaps of a door-like measurement passage. Pivot axes  40  for measurement are oriented at least essentially perpendicular to a measurement passage plane  30 , which corresponds to a plane of conveyance which lies parallel to the base plates  771  of the support body  772 . For measurement, i.e. during the passage of the animal body  9 , the flaps are swung up on the pivot axes  40  for measurement to record in particular a maximum lateral dimension of each animal body  9 . To bring the flaps into their initial or normal position for measurement after performing such a thickness measurement, doing so selectively and particularly before the complete passage of the animal body  9 , a holding means  4 , which supports the pair of flaps for pivoting movement, comprises a movement means not shown in  FIG. 1 , specifically a pivot mechanism with which the flaps can be pivoted completely out of the measurement passage space and/or conveyance passage space in each case by pivoting on a pivot axis  50  to move out, specifically to an outer position as previously defined in conjunction with the description of the measuring apparatus  11 . It can be seen that the sensors  2  of the measuring apparatus  12  are pivoted up or down as well with respect to the passage plane  30  and/or the plane of conveyance, while in contrast the pivot elements  21 ,  22  for measurement of the measuring apparatus  11  are arranged to swivel to the side of the measurement passage path  31 . The pivot axes  50  to move out of the measuring apparatus  12  are arranged parallel to the measurement passage plane  30  and perpendicular to the flap surfaces, for example. The measurement apparatus  12  is equipped with a control means  6  the same as measurement apparatus  11 .