Patent Publication Number: US-2021170537-A1

Title: Extraction device for a core drill

Description:
The present invention relates to an extraction device for a core drill. 
     BACKGROUND 
     In practice, there are known extraction devices that circumferentially enclose a core drill during a machining operation, so that drilling water that occurs when a core drilling operation is being carried out can be removed by way of the extraction device and contamination of the surroundings is prevented. 
     Since such an extraction device has a circumference that is in each case greater than the diameter of the core drilling tool, this has the effect for example of restricting whether core-drilled boreholes can be made in the region of corners of a space, and a minimum distance, dependent on the extraction device, from such hindrances is required. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an extraction device with which there is great freedom in the positioning of a core-drilled borehole, while as much drilling water as possible can be reliably removed by the extraction device from a core-drilled borehole under various spatial constraints. 
     An extraction device for a core drill is provided, comprising a housing which has at least one cavity, a cover and a wall connected to the cover around the periphery, wherein an extraction nozzle connected to the housing is provided, designed for attaching the extraction device to a suction device or a dust collector. It is proposed that the wall has at least one inlet opening, by way of which the cavity is connected to the surroundings, wherein a sealing device, which can be moved between an inoperative position, lying substantially against the wall of the housing, and an operative position, pivoted with respect to the inoperative position about a pivot axis, is connected to the housing on a side of the wall that is facing away from the cavity. 
     The extraction device is designed for being arranged completely radially outside the core drill, so that there is great freedom in the positioning of a core-drilled borehole and it is possible for core-drilled boreholes to be made even in a region near extremities, for example in the region of corners of a space, or near hindrances. Consequently, positioning of the core drill is not restricted by the extraction device. In the operating state of the extraction device, in which the extraction device is coupled to a suction device or a dust collector, the extraction device is sucked against the wall or on the floor by the negative pressure generated in the cavity by the suction device, in particular in a region near the core-drilled borehole to be made, and preferably stays in place without any further force being applied. In order to achieve this in an easy way, a side of the wall that is facing away from the cover preferably lies substantially in one plane completely around its periphery. 
     The drilling water that occurs during the core drilling is introduced into the cavity of the extraction device through the at least one inlet opening and is removed from it by the suction device by way of the extraction nozzle. Providing the at least one sealing device, designed in particular as a sealing panel or sealing strip, makes it possible in a structurally easy way to increase the size of a capturing region for the drilling water, so that a large proportion of the drilling water can be fed to the cavity of the suction device through the at least one inlet opening. 
     The fact that the sealing device can be moved between an inoperative position, lying substantially against the wall of the housing, and an operative position, pivoted with respect to the inoperative position about a pivot axis, means that, depending on the positioning with respect to a core drill and depending on the size of the core drilling diameter used, the sealing device can be easily set in each case in such a way that in the respective application as much of the drilling water as possible can be captured and fed to the at least one inlet opening. With the proposed extraction device, consequently, as much drilling water as possible can be reliably removed from a core-drilled borehole under various spatial constraints. By means of the sealing device, for example, a width of the extraction device that is effective for capturing drilling water can be increased in comparison with a design without a sealing device or with the sealing device in the inoperative position. If a core-drilled borehole is made for example in the region of a wall, sealing with respect to a lateral wall is possible for example by means of the sealing device, and drilling water can be prevented from running down on the lateral wall and not being collected by the extraction device. 
     The sealing device preferably has a substantially rectangular cross section, wherein in particular a longitudinal extent of the sealing device may vary depending on the application. 
     The sealing device is preferably pivotable between the inoperative position and the operative position about an angle of approximately 180°. As a result, the extraction device can be easily used for core drills with different core drilling diameters under various spatial constraints. 
     In order to easily prevent drilling water from passing through between the sealing device and the wall or the floor on which the extraction device is arranged in the operating state, the sealing device is preferably made from a flexible and/or elastic material, for example rubber, in particular nitrile rubber or ethylene-propylene-diene rubber, preferably with a Shore hardness of greater than 70. It may also be provided that the sealing device has a plastic part, which is in particular surrounded or encapsulated by a soft component, preferably of rubber. 
     The sealing device may be connected to the housing both fixedly, i.e. undetachably, and detachably, wherein the detachable arrangement has the advantage that the sealing device is easily exchangeable or can be easily replaced by a sealing device designed with different geometrical dimensions. 
     For easy attachment of the sealing device, it may be provided that the housing has a cylindrical fitting and the sealing device has a cylindrical recess corresponding to it, wherein an inside diameter of the recess is preferably smaller than an outside diameter of the fitting. The provision of an undersized connection makes it easily possible to ensure a secure hold of the sealing device in the respectively chosen position for use, for example by a tension that is provided in the rubber. The cylindrical fitting is preferably arranged in a lateral peripheral region of the housing, so that with the sealing device a region for capturing drilling water can be easily increased in size. 
     If a side of the sealing device that is facing a wall or a floor in the operative position of the extraction device is angled away from the fitting, as much surface pressure as desired of the sealing device with respect to the base material, i.e. the floor or the wall, can be achieved in a structurally easy way, so that good sealing with respect to the base material can be achieved. In this way, an advantageously large proportion of the drilling water can be captured. 
     In order to provide a capturing region for the drilling water that is as large as possible, the sealing device may be attached to the housing in a lateral peripheral region of the extraction device with respect to a transverse extent of the extraction device. 
     Preferably, two sealing devices are provided, attached to the housing in lateral peripheral regions of the extraction device facing away from one another. In this way, a capturing region for drilling water can be set particularly accurately by the sealing devices, and the great capturing width of the extraction device can be achieved. 
     In an advantageous design, it is provided that the wall has a first substantially planar wall region and a second substantially planar wall region, wherein a surface of the first wall region that is facing away from the cavity forms an obtuse angle with a surface of the second wall region that is facing away from the cavity The drilling water that occurs during the core drilling is introduced into the cavity of the extraction device through the at least one inlet opening and is removed from it by the suction device by way of the extraction nozzle. Providing the obtuse angle, which for example lies between 120° and 160° and is in particular approximately 140°, makes it possible to arrange the extraction device very near the core-drilled borehole to be made and to at least partially enclose the drill bit. In this way it is possible to extract a large proportion of the drilling water that occurs when making the core-drilled borehole. The extraction device is positioned on the wall during use in particular in such a way that the first wall region and the second wall region each run from a mutually facing region in an opposite direction in relation thereto upwardly with respect to a horizontal, so that gravitational force causes the drilling water to collect in a mutually facing region of the first wall region and the second wall region. 
     It has been found to be advantageous if the first wall region and the second wall region are connected to one another by means of a preferably planar third wall region. 
     The extraction device has a form that is conducive to removing a large amount of drilling water from the cavity if the wall has a fourth, in particular crescent-shaped or U-shaped, wall region, which is connected to the first wall region and to the second wall region. 
     In order to achieve favorable extraction of the drilling water introduced into the cavity, an extraction region that is in particular cylindrical and by which the extraction nozzle is in connection with the cavity may be arranged in the cavity. The extraction region is in particular arranged centrally in the housing, which is preferably designed mirror-symmetrically in relation to the extraction region. The extraction region preferably has a wall which extends from the cover into a plane that lies against the wall or the floor during the operation of the suction-attachment device. 
     In order to achieve as far as possible complete extraction of drilling water from the cavity in the event that the drilling water is not carried into a region near the extraction region by gravitational force during operation, at least one extraction channel may be provided, formed by the fourth wall region and a fifth wall region arranged substantially parallel to the fourth wall region, wherein the fifth wall region extends from the extraction region in particular up to a lateral peripheral region of the wall that is facing away from the extraction region. The fifth wall region is preferably connected to the cover and extends in particular up to a plane that lies against the wall or the floor during the operation of the suction-attachment device. As a result, the extraction channel by means of which drilling water is reliably transported out of a region remote from the extraction region in the direction of the extraction region by the flow effects achieved is formed by the fifth wall region and the fourth wall region. In order to be able to achieve favorable extraction of drilling water from the cavity, the extraction channel is preferably connected directly to the extraction region. 
     Extraction of drilling water from the cavity is particularly good if any spurious air streams during operation are as few as possible and as small as possible. This can be achieved by a contour that is as closed as possible of a wall of the extraction region that lies in particular on the base material during the operation of the extraction device. 
     In order to achieve an air flow of a speed of a desired level, required for good extraction of drilling water from the cavity, the extraction channel may have at least one element narrowing the flow cross section of the extraction channel. 
     It has been found that removal of drilling water from the cavity as well as desired is achieved if the extraction channel has a minimal cross section that is as small as possible, since as a result an air flow of a high speed can be achieved in the extraction channel when a suction device is connected to the extraction nozzle. This air flow of a high speed has the consequence that drilling water present in the cavity is entrained because of the Venturi effect and, given an appropriate design, can also be entrained against gravitational force. The minimal cross section of the extraction channel lies for example between 30 mm 2  and 45 mm 2 , preferably at approximately 37.5 mm 2 . 
     Preferably, the housing has three inlet openings, by way of which drilling water can be fed to the cavity from the surroundings, wherein one inlet opening is arranged in a connecting region of the first wall region to the fourth wall region, one inlet opening is arranged in a connecting region of the second wall region to the fourth wall region and one inlet opening is arranged in the wall in the region of the extraction region. 
     In order to achieve advantageous suction attachment of the suction-attachment device on a wall or the floor in a structurally easy way, a sealing element or a number of sealing elements may be provided, connected to the wall on a side facing away from the cover, in particular around the periphery. The sealing element or the sealing elements are preferably designed in such a way that, in a position of the suction-attachment device sucked against a wall or a floor, they seal the extraction channel with respect to the wall or the floor. 
     In order to achieve favorable handling of the extraction device, the housing may have a connecting device for the attachment of a holding device for the extraction device. By means of the holding device, for example a handle, the extraction device can be manually moved, for example for receiving drilling water. 
     Further advantages will become apparent from the following description of the figures. An exemplary embodiment of the present invention is depicted in the figures. The figures, the description and the claims contain numerous features in combination. A person skilled in the art will expediently also consider the features individually and combine them to form useful further combinations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the figures, components that are the same and components of the same type are designated by the same reference signs. 
       In the figures: 
         FIG. 1  shows a three-dimensional view of an extraction device, wherein sealing elements that are provided for interacting with a base material can be seen in the form of details; 
         FIG. 2  shows a plan view of the extraction device according to  FIG. 1 , wherein sealing devices are arranged in an operative position that is partially pivoted with respect to an inoperative position; 
         FIG. 3  shows a plan view of the extraction device according to  FIG. 1 , wherein sealing devices are arranged in an operative position that is completely pivoted with respect to the inoperative position; 
         FIG. 4  shows a three-dimensional view of the extraction device according to  FIG. 1  from below, wherein the sealing devices are arranged in the inoperative position; 
         FIG. 5  shows a view corresponding to  FIG. 4  of the extraction device according to  FIG. 1 , wherein the sealing devices are arranged in a partially pivoted operative position; 
         FIG. 6  shows a view corresponding to  FIG. 4  of the extraction device according to  FIG. 1 , wherein the sealing devices are arranged in the completely pivoted operative position; 
         FIG. 7  shows a view of the extraction device according to  FIG. 1  from below, with sealing devices arranged in the inoperative position; 
         FIG. 8  shows a view corresponding to  FIG. 7  of the extraction device according to  FIG. 1 , wherein the sealing elements are not shown; 
         FIG. 9  shows a three-dimensional view of the extraction device according to  FIG. 1  from below, wherein the sealing devices are not shown; 
         FIG. 10  shows a sectional view of the extraction device according to  FIG. 1  with the sealing elements, wherein an extraction channel can be seen more specifically; 
         FIG. 11  shows a three-dimensional view of a detail of the extraction device according to  FIG. 1  without the sealing elements, wherein an inlet opening that is arranged in a wall of the housing can be seen more specifically; 
         FIG. 12  shows a view corresponding to  FIG. 11  of the extraction device according to  FIG. 1  with the sealing elements; 
         FIG. 13  shows a three-dimensional view of a detail of the extraction device according to  FIG. 1  without the sealing elements, wherein a further inlet opening that is arranged in the wall of the housing can be seen more specifically; and 
         FIG. 14  shows a view corresponding to  FIG. 13  of the suction device according to  FIG. 1  with the sealing elements. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  to  FIG. 14  show an extraction device  1 , which is intended for interacting with a core drill. The extraction device  1  has a housing  4 , which is designed with a cover  2  and a wall  3  and altogether has the shape of a V. The extraction device  1  is designed in the present case as substantially symmetrical in relation to a longitudinal center plane  6  (see, e.g.,  FIG. 3 ), wherein an extraction nozzle  5  is connected to the cover  2  in a central region. The connection nozzle is provided for connecting the extraction device  1  to a suction device or a dust collector, by means of which a negative pressure can be generated in a cavity  7  of the extraction device  1  that can be seen for example in  FIG. 4 . 
     As can be seen more specifically for example in  FIG. 8 , the wall  3  is in the present case arranged substantially perpendicularly to the cover  2  and connected to the cover  2  around the periphery. The wall  3  has in this case a first wall region  10 , a second wall region  11 , a third wall region  12  and a fourth wall region  13 . The first wall region  10 , the second wall region  11  and the third wall region  12  are in the present case substantially planar, wherein the first wall region  10  is connected to the third wall region  12  and the second wall region  11  is connected to the third wall region  12  in a peripheral region of the third wall region  12  that is facing away from the region of attachment of the first wall region  10  to the third wall region  12 . A surface  14  of the first wall region  10  that is facing away from the cavity  7  forms an obtuse angle  16 , which in the present case is approximately 140°, with a surface  15  of the second wall region  11  that is facing away from the cavity  7 . 
     The fourth wall region  13  is U-shaped or crescent-shaped, wherein the fourth wall region  13  has substantially planar portions  17 ,  18 ,  19  respectively running substantially parallel to the first wall region  10 , the second wall region  11  and the third wall region  12 . The fourth wall region  13  is connected in a peripheral region to a peripheral region of the first wall region  10  that is facing away from the third wall region  12  and is connected in a further peripheral region to a peripheral region of the second wall region  11  that is facing away from the third wall region  12 . 
     As can be seen for example in  FIG. 7  and  FIG. 8 , arranged in a peripheral region of the wall  3  that is facing away from the cover  2  in the present case are three sealing elements  20 ,  21 ,  22 , which are connected to the wall  3  almost completely around the periphery and can be fitted on the respective region  10 ,  11 ,  12  or  13  of the wall  3 . The first sealing element  20  is in this case connected to the first wall region  10  and has substantially a longitudinal extent comparable to the first wall region  10 . The second sealing element  21  is connected to the second wall region  11  and has substantially a longitudinal extent comparable to the second wall region  11 . By contrast, the third sealing element  22  is connected to the fourth wall element  13  and has substantially a longitudinal extent comparable to the third wall region  13 . 
     In the cavity  7  there is also arranged an extraction region  25 , which is formed here with a wall  26  that is cylindrical in certain regions, wherein the wall  26  is connected to the cover  2 . The wall  26  has an extent in terms of height such that, in an operating state in which the extraction device  1  is held on the base material, the wall  26  is preferably directly in contact with the base material. Consequently, in particular in the operating state of the extraction device  1 , on a side facing the base material, all of the sealing elements  20 ,  21 ,  22  and the wall  26  of the extraction region  25  lie substantially in one plane. In the operating state of the extraction device  1 , the extraction device  1  is held against the base material, for example a floor or a wall, by a negative pressure generated in the cavity  7  by the suction device, preferably without any further holding device. 
     Also provided in the present case are two extraction channels  30 ,  31 , which are formed by the fourth wall region  13  and respectively a fifth wall region  32 , running substantially parallel to the fourth wall region  13 , and a sixth wall region  33 , running substantially parallel to the fourth wall region  13 . A distance between the fourth wall region  13  and the fifth wall region  32  and a distance between the fourth wall region  13  and the sixth wall region  33  is constant, in particular over almost the entire extent of the extraction channels  30 ,  31 , and in the present case is approximately 6 mm. The fifth wall region  32  and the sixth wall region  33  are in this case designed in the form of panels and are respectively connected to the cover  2 . These wall regions  32  and  33  have an extent in terms of height such that, in the operating state of the extraction device  1 , they come into contact with the sealing element  22 , so that the respective extraction channel  30  or  32  is sealed by the sealing element  22  on a side facing away from the cover  2 . 
     As can be seen for example in  FIG. 8 , the fifth wall region  32  and the sixth wall region  33  are respectively connected to the wall  26  of the extraction region  25 , which has a clearance  35  in the region of the longitudinal center plane  6 , so that the respective extraction channel  30 ,  31  is directly in contact with the extraction region  25 . The fifth wall region  32  extends from the extraction region  25  substantially parallel to the fourth wall region  13  into a first peripheral region  37  of the housing  4  that is facing away from the longitudinal center plane  6 . Similarly, the sixth wall region  33  extends from the extraction region  25  substantially parallel to the fourth wall region  13  into a second peripheral region  38  of the housing that is opposite from the first peripheral region  37  with respect to the longitudinal center plane  6 . 
     Both in the first extraction channel  30  and in the second extraction channel  31 , an element  40  or  41  that narrows or reduces the size of the flow cross section of the respective extraction channel  30  or  31  in the region of the element  40  or  41  is arranged in the present case in a region of the respective extraction channel  30  or  31  that is facing the first peripheral region  37  or the second peripheral region  38 , respectively. In the region of the element  40  or  41 , the extraction channel  30  or  31  has a width of preferably 2 mm to 3 mm, in particular approximately 2.5 mm, and a height of preferably 10 mm to 20 mm, in particular approximately 15 mm, so that the extraction channel  30  or  31  has in this region a cross section of 20 mm 2  to 60 mm 2 , in particular of approximately 37.5 mm 2 . In the operative position of the extraction device  1 , a cross section of the extraction channel  30  or  31  through which a flow can pass is laterally bounded in the region of the respective element  40  or  41  by the fifth wall element  32  or the sixth wall element  33 , respectively, and the third sealing element  22  (see, e.g.,  FIG. 7 ). On the other hand, the cross section of the extraction channel  30  or  31  through which a flow can pass is bounded perpendicularly thereto, in the vertical direction, on the one hand by the respective element  40  or  41  and on the other hand by the third sealing element  3 , which seals the extraction channel  30  or  31  in the operative position of the extraction device  1  on an opposite side. It can be easily ensured by an appropriate cross-sectional design of the extraction channel  30  or  31  that for example drilling water located in the cavity  7  is removed from the cavity  7 , in particular completely, by way of the extraction channel  30  or  31  and the extraction region  25 . 
     As can be seen more specifically in  FIG. 11  and  FIG. 12 , an inlet opening  44 , by way of which drilling water can be fed from the surroundings U (see, e.g.,  FIG. 4 ) to the cavity  7  in the operative position of the extraction device  1 , is formed in an abutting region of the fourth wall region  13  adjacent to the first wall region  10  by a clearance  43  in the first wall region  10 . In  FIG. 12  it can be seen that the inlet opening  44  is arranged substantially underneath the first sealing element  20 . Comparable to the inlet opening  44 , an inlet opening formed by a clearance in the second wall region  11  is provided in the opposite peripheral region of the housing  4 . 
     Shown in  FIG. 13  and  FIG. 14  is a further inlet opening  45 , which is formed by two substantially parallel wall regions  47  and  48  of the wall  26  of the extraction region  25  at a distance between the first sealing element  20  and the second sealing element  21 . Through the further inlet opening  45 , drilling water that is fed in for example from the surroundings U (see, e.g.,  FIG. 4 ) can be passed directly into the extraction region  25 . 
     In the operative position of the extraction device  1 , both the inlet openings  44  and the further inlet opening  45  are in particular directly adjacent to the base material, so that drilling water can be easily introduced into the cavity  7  through the inlet openings  44 ,  45 . 
     As shown more specifically for example in  FIG. 2  to  FIG. 6 , the extraction device  1  has in the present case two sealing devices  50 ,  51 , which are mounted on the housing  4  in each case pivotably about a pivot axis  57  or  58 , respectively. The sealing devices  50 ,  51 , designed for example as sealing strips, are in the present case in the form of panels and are made from an elastic and flexible material, for example rubber, and are respectively mounted on a side of the first wall region  10  or the second wall region  11  that is facing away from the cavity  7 . For this purpose, a cylindrical fitting  54  or  55  is respectively arranged on the housing  4  in the form of a holding pin, on which the respective sealing device  50 ,  51  is fitted by a corresponding cylindrical recess  56  or  57 . An inside diameter of the recess  56  or  57  is in this case preferably smaller than an outside diameter of the fitting  54  or  55 , so that the sealing device  50  or  51  is securely held in the position applicable at the time in each case. 
     The respective sealing device  50  or  51  can be adjusted between the inoperative position, which is shown for example in  FIG. 4  and in which the sealing device  50  or  51  is arranged substantially parallel to the wall region  10  or  11 , and various operative positions according to  FIG. 2  and  FIG. 3 . The sealing devices  50  or  51  can in this case be pivoted independently of one another in the present case with respect to the inoperative position, by an angle of approximately 180° about the pivot axis  57  or  58 . In the inoperative position, the extraction device  1  takes up an advantageously small installation space. 
     On a side  52  that is facing a base material in the operative position of the extraction device  1 , the sealing devices  50  or  51  are angled, wherein a peripheral region  60  that is facing away from the respective fitting  53  or  54  has in an inoperative position of the extraction device  1  a greater extent in the direction of a direction interacting with a base material in the operative position than a region that is facing the fitting  53  or  54 . As a result, a sealing contact of the sealing device  50  or  51  against the base material is ensured in the operative position of the extraction device by a large achievable surface pressure. Furthermore, such a design of the sealing devices  50  or  51  allows unevennesses of a base material and tolerance variations to be compensated. 
     The extraction device  1  is intended for interacting with a core drill, for example a diamond drill, wherein the extraction device  1  may be designed as a holding aid for the extraction device  1 . The V-shaped design of the first wall region  10  with respect to the second wall region  11  has the effect that the extraction device  1  can preferably be arranged underneath a drill bit of the core drill, in particular directly adjacent to the drill bit, so that drilling water spun off during core drilling can be received by the extraction device  1 , in particular completely. An appropriate setting of the sealing devices  50  or  51  makes it easily achievable that a particularly large proportion of the drilling water spun off from the drill is fed to the extraction device  1 . An effective width of the extraction device  1  can be easily increased by the sealing devices  50  or  51  in the operative position. Furthermore, sealing can be obtained by means of the sealing devices  50  or  51  in the operative position, preferably with respect to a side wall arranged perpendicularly in relation to the wall to be machined. 
     If the extraction device  1  is connected by means of the extraction nozzle  5  to a suction device or a dust collector, a negative pressure is produced in the cavity  7  when the extraction device  1  is arranged on a base material, in particular a wall, by which the extraction device  1  is held firmly and securely against the base material. The negative pressure in the cavity  7  and the gravitational force have the effect that the drilling water is sucked into the cavity  7  through the inlet openings  44  or the further inlet opening  45  and is removed from the cavity  7  by way of the extraction region  25  and the extraction nozzle  5 . 
     The shallow V shape of the housing  4  of the extraction device  1  has the effect that an angular range of the extraction device  1  in an arrangement of the extraction device  1  on a wall, in which the third wall region is arranged at a lower level than the first wall region  10  and the second wall region  11 , is relatively small. In this case, the drilling water is fed directly to the extraction region  25  through the further inlet opening  44  or is passed through the portions  17  and  18  of the fourth wall region  13 , which are designed to be substantially parallel to the first wall region  10  and the second wall region  11 , by gravitational force in the direction of the extraction region  25 . 
     In the operative position of the extraction device  1 , it may be provided that the extraction device is arranged skewed in such a way that the first wall region  10  or the second wall region  11  is arranged with a region that is facing the peripheral region  37  or  38  of the housing  4  lower than a region that is facing the longitudinal center plane  6 . In this case, drilling water would collect in a lateral peripheral region of the cavity  7  under the effect of gravitational force alone. The provision of the extraction channels  30 ,  31  ensures that even in this case drilling water is removed from the cavity  7 , in particular almost completely. As a result, contamination of the wall after removal of the extraction device  1  from the wall can be prevented. 
     LIST OF REFERENCE SIGNS 
     
         
           1  Extraction device 
           2  Cover 
           3  Wall 
           4  Housing 
           5  Extraction nozzle 
           6  Longitudinal center plane 
           7  Cavity 
           10  First wall region 
           11  Second wall region 
           12  Third wall region 
           13  Fourth wall region 
           14  Surface of the first wall region 
           15  Surface of the second wall region 
           16  Angle 
           17  Portion of the fourth wall region 
           18  Portion of the fourth wall region 
           19  Portion of the fourth wall region 
           20  First sealing element 
           21  Second sealing element 
           22  Third sealing element 
           25  Extraction region 
           26  Wall 
           30  First extraction channel 
           31  Second extraction channel 
           32  Fifth wall region 
           33  Sixth wall region 
           35  Clearance 
           37  First peripheral region of the housing 
           38  Second peripheral region of the housing 
           40  Element 
           41  Element 
           43  Clearance 
           44  Inlet opening 
           45  Further inlet opening 
           47  Wall region 
           48  Wall region 
           50  First sealing device 
           51  Second sealing device 
           52  Side 
           53  Fitting 
           54  Fitting 
           55  Recess 
           56  Recess 
           57  Pivot axis 
           58  Pivot axis 
           60  Peripheral region 
         U Surroundings