Doctor units for cleaning or coating purposes

p0001The invention relates to a doctoring apparatus comprising a doctor blade for cooperation with a movable surface, a holding device for the scraper blade, a means for generating a contact pressure for pressing the doctor blade to the movable surface and means for at least indirect detection of the pressing force and / or the pressure on at least a portion of the extent of the scraper blade at least indirectly characteristic. The invention further relates to a squeegee device.

p0002Scraper devices for cleaning movable surfaces or doctor devices for equalization of application media of movable surfaces are previously known in a variety of styles from the prior art. The appointment of the blades in the opposite direction of movement of the movable surface scraper devices is performed while in doctor devices, in particular scraping devices, the job in the movement direction and distance is carried to the surface. When used in machines for the production of fibrous webs, which are generally characterized by a very large machine width, the problem is often that to ensure safe operation across the width of a predefined necessary contact pressure and / or a required contact pressure distribution and / or a uniform to obtain distance between blade and surface. The due large blade lengths deflection plays an essential role. Further, the contact pressure and / or the contact pressure during operation may vary due to other influences. To measure the contact force and / or the contact pressure and its distribution profile devices are therefore already known for at least indirectly detecting the pressing force and / or the pressure at least indirectly characterizing. The measurement is carried out either directly or indirectly.

p0003The publication <patcit id="pcit0001" dnum="EP1259377B1"><text>EP 259 377 B1 1</text></patcit> is previously known an embodiment in which a scraper device on the doctor blade at least a strain gauge sensor is arranged, with which the aim of the scraper on the roller contact pressure of which is measurable. The measurement of the contact pressure can take place also during the normal operation, since the scraper does not need to be lifted off the roller. The measurement of the contact pressure by means of expansion measuring strip sensor is based on the principle of deflection of the doctor blade in function of the contact pressure, wherein the strain gauge is stretched or compressed by the bending of the scraper and thus changes its resistance. This can be measured and converted into the corresponding pressure. The arrangement of a plurality of strain gage sensors on the width of the movable surface is distributed to the scraper blade. Since the strain gauges react to a geometric change with a change in electrical conductivity, whereby the applied pressure can be determined by means of calibration, however, a power source is imperative that continuously conduct current to the sensors.

p0004A further embodiment of a to be used in a machine for producing fibrous webs scraper device with a support beam arranged thereon a blade holder, in which a scraper blade for scraping off the roll or a corresponding moving surface, is known from <patcit id="pcit0002" dnum="EP1244850B1"><text>EP 244 850 B1 1</text></patcit> previously known. The doctor blade or the blade holder in this case have one or more sensors, which are arranged inside or outside and are provided to measure the wear of and / or stress in the blade holder and / or the doctor blade, whereby in the one or more as a sensor serving optical fibers the interior of the blade holder and / or the doctor blade are arranged. This version is designed for the specific sensor design. The optical fibers are integrated in the assembly, which must be considered in the structural design.

p0005The publication <patcit id="pcit0003" dnum="EP1584745B1"><text>EP 584 745 B1 1</text></patcit> is previously known a calibration device by means of which the contact pressure of an applied in a paper machine at the periphery of a roller or a cylinder blade of a doctor apparatus can be controlled. This device is characterized in that in a holding blade a sensor holder is provided, which is provided with a pressure sensor, wherein the holding blade, the sensor holder and the pressure sensor are so positioned that the position of the pressure sensor on the circumference of the roll or cylinder to the place of investment of key blade. This device is used for calibrating, in particular for determining the contact pressure, wherein the blade is changed after the calibration by the actual doctor blade, with the contact pressure of the blade edge can be produced reproducibly. The single pressure sensor may be designed in various ways. Preferably, this is formed as a tactile pressure sensor, in particular a piezoelectric sensor. The solution is characterized in that although can be done calibration of the contact pressure in the run, but will not continue to be monitored in the application of pressure and there is also no adjustment to changing conditions due to lack of monitoring.

p0006The invention therefore addresses the problem of further developing a scraper device of the type mentioned in such a way that on the one hand, the contact pressure and the distribution profile across the width of the movable surface can be determined as needed, the device for detecting the contact pressure operate autonomously and also the means for detection is used for any scraper lengths. The inventive solution is thereby distinguished by a low structural and control complexity.

p0007The inventive solution is characterized by the features of claim 1. Advantageous embodiments are given in the subclaims. A doctor blade device according to the invention is described in claim 28th

p0008A doctoring apparatus comprising a doctor blade for cooperation with a movable surface, a holding device for the scraper blade, a means for generating a contact pressure for pressing the doctor blade to the movable surface and means for at least indirect detection of the pressing force and / or the contact pressure at least indirectly, descriptive size over at least a portion of the extension of the doctor blade is, according to the invention characterized in that the means for at least indirect detection of the pressing force and / or the pressure at least indirectly characterizing over at least a portion of the extension of the doctor blade comprises at least one piezoelectric sensor.

p0009Piezoelectric sensors are active sensors which preferably move to fast and timely recording dynamically changing metrics used. The operation of piezoelectric sensors is based on the induction of stresses under the influence of elastic stress states in the support area of ​​the piezoelectric sensors. An external power supply is not necessary, which means considerable constructive and energetic advantage harbors. The pressure can be determined in real time. The sensors build very small and compact so that they can be arranged free of hinder the operation of the doctor blade on or against this. Furthermore, piezoelectric sensors are very robust and can deliver reproducible values ​​over longer periods. The sensors enable a reliable detection during operation of the scraper device. This information may be on blades of different materials and with different surface finishes.

p0010When the scraper device is a device for cleaning of movable surfaces. The appointing of the blade takes place aligned opposite to the direction of movement of the movable surface.

p0011Since the piezoelectric sensor detects the voltage states in its support area, are for determining pressure profiles along the length of the doctor blade, which corresponds to the extension of the doctor blade viewed in the width direction of the movable surface and / or preferably is provided over the length of scraper blade portions, a plurality of piezoelectric sensors.

p0012In an advantageous further development of the doctor blade comprises at least two doctor blades parts which considered over the length of the doctor blade are arranged adjacent to each other, wherein at least one of the scraper blade portions having piezoelectric sensors. The scraper blade portion, the piezoelectric sensors having forms a measuring bar. By subdividing the scraper blade into several sections scraper blades of varying lengths can be formed by single standardized prefabricated doctor blade sections, which are then used universally. By prefabrication of this measuring beam can be integrated maintained as standardized functional units and viewed at any point in a scraper blade structure along the length of the doctor blade. The measurement locations can be arranged in any order with respect to their location. The measuring bar form a functional unit for cleaning the surface and for the simultaneous detection of Anpresszustandes the blade.

p0013According to an advantageous embodiment, the over the length of the doctor blade and / or the individual measuring beam arranged piezoelectric sensors are arranged at the same distance from the operative to the movable surface blade end of the blade to simplify the evaluation of the measured variables.

p0014Preferably, the evaluation of the measured variables, and any mountability the form of a measuring beam scraper blade parts are arranged each considered a constant distance from each other in length direction of the doctor blade along the length of the doctor blade and / or a doctor blade member disposed piezoelectric sensors for simplicity. This allows meaningful distribution profiles for the pressure over the length of the doctor blade with support from a large number of measuring points are created.

p0015To avoid jeopardizing their operation, the piezoelectric sensors can be located on the the investment field forming on the surface doctor blade side facing away blade base, but it is also possible to arrange the sensors on the blade top or on both sides of the blade, if advantageous or necessary by the installation situation is. According to a particularly advantageous embodiment for the direct detection of the measured values, the piezoelectric sensors are arranged within the extent of the bearing region on the movable surface. When placed on the blade base, no special modifications are required for this. The piezoelectric sensors can be arranged in a simple manner on the blade surface, for example by means of an adhesive compound.

p0016In an alternative embodiment, the piezoelectric sensors can be arranged in arranged on the blade surface depressions. Thereby, an arrangement in the contact region of the scraper blade at the scraper blade front is possible.

p0017According to a preferred embodiment, the piezoelectric sensors may have a round shape whose extension is equal in two mutually perpendicular in-plane directions substantially. This form is easy to manufacture.

p0018According to an alternative embodiment, the piezoelectric sensors may also have an elongated shape, the extension of which varies in size in two mutually perpendicular in-plane directions. This embodiment allows a targeted adaptation of the orientation of the sensors relative to each other and relative to an extending direction of the doctor blade with the corresponding possibility of modeling the evaluable signal.

p0019Particularly preferably, the elongated piezoelectric sensors are arranged relative to each other in parallel in terms of their greater extension. Characterized a homogenization of the sensor signal over the entire width is possible.

p0020The elongated piezoelectric sensors can be arranged inclined at an angle to the length direction of the doctor blade. The angle should be greater than 0 °, preferably greater than 45 °, particularly preferably approximately 90 °. The greater the angle between the extension direction of the sensor and the extending direction of the doctor blade, the more accurately the force acting on the sensor can be measured.

p0021In a particularly advantageous embodiment of the individual, the piezoelectric sensor supporting beam section is decoupled to the doctor blade and / or the individual scraper blade portion of the other support areas or piezoelectric sensors free areas to actually only the stress conditions in the assembly area of ​​piezoelectric sensors free from influence by deformation states to capture the adjacent area. The scraper blade and / or the individual doctor blades have part to the simplest case, both sides of a piezoelectric sensor open-edge recesses or notches on.

p0022The piezoelectric sensor actual values ​​detected as a donor of measured values, which can be evaluated and / or can be used as input variables for controls / regulations. The piezoelectric sensors of a doctor blade and / or a doctor blade portion are to individually or in groups or together with a data receiving and / or evaluation device coupled. The coupling may be as an electrical coupling or performed wirelessly. In the first case includes this line connections, which find single lines or a serial interface using. The wiring and the sensors provided with portions of the doctor blade can be completely or partially protected by a suitable cover or enclosure. The wireless connection can be made via infrared or radio. Given by corresponding transmitting and / or receiving devices are required, which are coupled to the sensor and / or the data acquisition and / or evaluation device or form a structural unit.

p0023The data acquisition and / or evaluation device is preferably formed for further processing and adjustment of pressure by a control and / or regulating device and / or a personal computer.

p0024The inventive solution to the use of piezoelectric sensors is also applicable for doctor devices. These include a blade, however, for equalizing of a medium on a movable surface, a holding device for the blade, a means for generating a pressure for the purpose of positioning of the blade relative to the movable surface and means for at least indirect detection of the pressing force and / or the pressure on at least a portion of the extension of the blade at least indirectly characteristic. The means for at least indirect detection of the pressing force and / or the pressure at least indirectly characterizing comprises at least one piezoelectric sensor, preferably a plurality of on the extension of the blade in length direction arranged piezoelectric sensors. Regarding the arrangement of the length, with respect to the blade end and the surfaces and the coupling with data processing devices, the same statements as for the doctor apparatus are already running.

p0025The inventive solution is explained with reference to figures. This feature is shown in detail:<dl id="dl0001"><dt>FIGS. 1a and 1b</dt><dd>illustrate an inventively constructed scraper device in two views;</dd><dt>FIG. 2</dt><dd>illustrates a further development of a scraper inventive apparatus <figref idrefs="f0001">figure 1</figref> with a doctor blade from a plurality of scraper blades parts;</dd><dt>FIGS. 3a and 3b</dt><dd>illustrate a development of a scraper device according to <figref idrefs="f0001">figure 1</figref> with a doctor blade from a plurality of scraper blades parts;</dd><dt>Fig. 4</dt><dd>illustrates a particularly advantageous embodiment of an inventively embodied measuring beam;</dd><dt>Fig. 5</dt><dd>illustrates an embodiment with an alternative arrangement of piezoelectric sensors <figref idrefs="f0001">figure 1b</figref>;</dd><dt>FIGS. 6a and 6b</dt><dd>illustrate two embodiments of inventive devices having different data transmission options.</dd></dl>

p0026The <figref idrefs="f0001">Figures 1a and 1b</figref> illustrate in schematically greatly simplified representation the basic structure of an inventive scraper device 1 in two views. The<figref idrefs="f0001">figure 1a</figref> illustrates a view of law, <figref idrefs="f0001">Figure 1 b</figref> a view A in accordance with <figref idrefs="f0001">figure 1a</figref>, For clarity the individual directions of a coordinate system is applied to the scraper device first This corresponds to the use in machines for producing material webs which usually applied to this coordinate system. The X-direction describes the machine direction, ie the direction of passage of the material web, the Y direction, the width direction and the Z-direction, the height direction.

p0027The scraper device 1 comprises at least one scraper blade 2, which is mounted in a blade holder 3 to a supporting device 4th The scraper blade 2 is flying, ie unilaterally mounted in the region of an end portion 7 in the blade holder. 3 The remaining part of the doctor blade 2 extends cantilevered away from the blade holder. 3 Regarding the embodiment of the blade holder 3 pass a variety of ways, to which, as already known, is not discussed in detail. The blade holder 3 is, however, preferably formed of several parts.

p0028Further, the doctor blade 2 is at least one means 5 for generating a contact pressure for pressing against a movable surface 6, associated in particular in the form of a rotatable curved surface. The rotatable surface is formed here generally for use in machines for producing material webs, in particular fibrous webs in the form of paper, cardboard or tissue webs of the circumferential surface of a cylindrical body in the form of a roll or a cylinder. The scraper blade 2 cleans the movable surface 6 and, particularly in the case of a material web break, the avoidance of a wrapping of the movable surface forming roller with the material web. For this, the doctor blade 2 with their free projecting end 13 acts at least indirectly with the movable surface 6 tribological together. The doctor blade 2 is made opposite to the direction of movement of the rotatable surface 6th The Anstellbereich the doctor blade 2 is denoted by 12th

p0029The scraper device 1 further comprises at least one means 8 for at least indirectly detecting the contact force and / or the contact pressure of the doctor blade 2 to the movable surface 6 at least indirectly characterizing. "At least indirectly" it includes both a direct detection of the pressure as well as the detection of the contact pressure on functional relationships or in a ratio to each other sizes.

p0030The device 8 comprises according to the invention at least one, preferably a plurality of arranged on the scraper blade 2 or in this integrated piezoelectric sensors 9. In this case, considered over the extent of the doctor blade 2 in the width direction or Y-direction of the movable surface 6, the length I 2 corresponds to the doctor blade, preferably at least two, most preferably provided a plurality of such piezoelectric sensors 9.1 to 9.n, which may be arranged depending on the embodiment in various ways spaced apart. Such piezoelectric sensors 9.1 to 9.n. produce under elastic stresses a current by forming electric charges. This can be detected and used to determine the contact pressure and the contact force. A great advantage of the piezoelectric sensors 9.1 to 9.n is that they need no power source.

p0031In that in <figref idrefs="f0001">Figure 1 b</figref> illustrated embodiment is a view A of a doctor blade 2 from above in accordance with <figref idrefs="f0001">figure 1a</figref> reproduced, which was omitted on the presentation of the blade holder 3 in detail. It is apparent that the doctor blade has 2 piezoelectric sensors 9.1 to 9.n.. The assembly is done in the case shown at a Klingenrück- or -oberseite 10 of the scraper blade, that is of the turbulent surface 6 facing away surface of the doctor blade 2. This is a the Anstellbereich 12 forming Klingenvorder- top or bottom 11 against. considered the arrangement on the blade top 10 when in use has the advantage that the individual piezoelectric sensors are 9.1 to 9.n., arranged as in the direct area of ​​influence of the doctor blade 2 on the movable surface 6, which corresponds to the angle of attack or bearing region 12 of the doctor blade 2 can. Thereby, the deformations of the doctor blade 2 can be determined optimally in actual deformation area or area of ​​influence and the pressure will be very accurately detected in this area.

p0032The arrangement on the blade base 11, which is directed in use position to the movable surface 6 is also possible, here, however, a shift from the effective range out or an arrangement in recesses on the blade front side 11 to avoid interfering effects would be required. Even a two-sided arrangement of sensors 9.1 to 9.n. is possible if the installation situation or the operating parameters so require or make it appear to be advantageous. The arrangement may also be carried out between the blade holder 3 and the Klingenendbereich 13 so that the pressure over the propagating in the doctor blade 2 voltages in the range of the blade holder 3 or between this and the Klingenendbereich 13 can be determined.

p0033The <figref idrefs="f0001">figure 1b</figref> illustrates an embodiment of a substantially across the width b₆ the movable surface 6 extending scraper blade 2. The extent corresponding to the length I of the scraper blade. The arrangement of piezoelectric sensors 9.1 to 9.n. is characterized in that it viewed with uniform distance a from each other in the width direction of the movable surface 6, respectively are arranged in longitudinal direction of the doctor blade. 2 The arrangement is made further to the blade base 10 of the scraper blade 2 on a theoretical axis which is arranged parallel to the bearing axis of the movable surface 6, in particular of the rotating roller or the cylinder. This arrangement also corresponds to the arrangement with the same distance from the blade holder 3 or equal distance c viewed from the blade end 13 from.

p0034The <figref idrefs="f0001">figure 1b</figref> illustrates a fundamental way. Advantageous further developments are in the<figref idrefs="f0002 f0003 f0004">Figures 2 to 6</figref> reproduced.

p0035According to <figref idrefs="f0002">figure 2</figref> is subdivided into individual scraper blade parts 2.1 to 2.n the scraper blade. The scraper device 1 is in this case over the width b₆ the movable surface of each scraper blade parts 2.1 to 2.n, here 2.1 to 2.3, together. Each of these individual doctor blades parts 2.1 to 2.3 is in this case fixed to the support means 4 in the blade holder. 3 In this case, 2.1 to 2.3, respectively be 5.1 to 5.3 assigned for pressing its own means a scraper blade portion, or a device 5 is all scraper blades parts 2.1 to 2.n associated together. This embodiment is exemplified in the<figref idrefs="f0002">figure 2</figref> clarified. The individual doctor blades parts 2.1 to 2.3, according to the embodiment in<figref idrefs="f0002">figure 2</figref> preferably be configured identically. These are the same length I₂ characterized. The arrangement is preferably carried out side by side or adjacent to each other on the extension of the doctor blade 2 in the width direction of the movable surface. 6

p0036The device 8 for at least indirect detection of the pressing force and / or the pressure at least indirectly characterizing here comprises a plurality of component devices 8.1 to 8.3, which are respectively arranged at each doctor blade parts 2.1 to 2.3. This means that each doctor blade parts 2.1 to 2.3 in each case at least one or a plurality of piezoelectric sensors to 9:11 9.nn, here 11/9 to 1/9 n, 9:21 to 9:31 and 9.2n to 9.3n, exhibit. By dividing into several scraper blades parts 2.1 to 2.n, so-called measuring beam 14, are here formed 14.1 to 14.3, so that the measurement locations across the width of the movable surface 6 randomly distributed can be arranged. Furthermore, the individual measuring beam can be 14.1 held to 14.3 as a prefabricated standard modules for doctor blades 2 that get in the formation of a doctor blade 2 is used, and thus are 6 used for different widths of the movable surface by the measuring beam 14.1 to 14.n in the desired and optimally be combined with each other or with free of piezoelectric sensors blade parts.

p0037The <figref idrefs="f0002">figure 2</figref> a illustrates an embodiment with preferably uniformly executed and uniformly across the width of the movable surface 6 arranged distributed measuring beam 14.1 to 14.n. In contrast, illustrates the<figref idrefs="f0002">3a</figref> an embodiment of a doctor blade 2 with differently sized metering bar 1.14 to 5.14 to simulate the required length of the doctor blade 2. Because of the possibility of the arrangement and subdivision of the doctor blade 2 in single scraper blade parts 2.1 to 2.5, which may be of different sizes, it is possible to vary long doctor blades 2 to simulate. The individual lengths of the scraper blade parts 2.1 to 2.5 are here with I_2.1 until I_2.5 designated. The individual measuring beam 14.1 to 14.n are here exemplified respectively by a different number of piezoelectric sensors 9.11 9:21 to 9:22, 9:31 to 9.3n, 9:41 to 9:42 and 9.5 characterizes. Furthermore, can be measured with this version different roll widths. In the illustrated case, the individual sensors of a measuring beam 14.2, 14.3 and 14.4 are also arranged in each case at a constant distance a from one another.

p0038Depending on the desired accuracy and number of measuring points along the width b₆ the movable surface 6, in particular of the cylinder or roll, it is also conceivable to use a smaller number of scraper blades parts 2.1, 2.3 and 2.5 forming measuring beam 14.1 to 14.3 to use, for example, one on the drive side, one on the tender side and one in the middle the roller, the balance of scraper blade parts are 2.2 and 2.4 free of such facilities 8 for at least indirectly detecting the pressing force and / or the pressure at least indirectly characterizing such as in <figref idrefs="f0003">3b</figref> shown.

p0039To keep just at thus formed measuring beam 14.1 to 14.n with greater length the individual adjacently arranged sensors 9.1 to 9.n. free of the deformation in the adjacent areas, such as in <figref idrefs="f0003">figure 4</figref> incorporated in a view of the doctor blade 2 on both sides next to each of the piezoelectric sensors 9.1 to 9.n. cuts, particularly in the form of open-edged recesses 15:11 to 15.nn the blade material, so that the individual piezoelectric sensor 9.1 to 9.n. only at its carrier range 16.1 to 16.n existing load measures. The incisions or recesses 15:11 to 15.nn which are referred to herein, for example, the piezoelectric sensor 9.1 with 15.11 15:12, for the sensor 9.2 with 15:21, 15:22 and for the illustrated sensor 9.3 with 15:31 and 15:32 are, the mechanical, the related deformation decoupling of the individual piezoelectric sensors 9.1 to 9.3 from the respective adjacent scraper blade portions. The regions between the individual piezoelectric sensors 9.1 to 9.3 are each free of such sensors and here designated 17.1 and 17.2, with the deformation in the areas 17.1 and 17.2 due to this decoupling, in particular the mechanical decoupling of the carrier ranges 1.16 to 3.16 adjacent the , no effect of piezoelectric sensors free areas on the measurement.

p0040The <figref idrefs="f0003">figure 5</figref> illustrated for illustrative purposes, another embodiment with a measuring beam 14.1 at different distances a₁, a₂, a₃ each other in the length direction of the doctor blade 2 seen arranged piezoelectric sensors 9.1 to 9.n. The individual piezoelectric sensors 9.1 to 9.n. are further arranged at different distances relative to the blade end. 13 This spacing is here with c₁ and c₂ designated.

p0041The reading of the data and the processing can be done in various ways. According to a first embodiment in<figref idrefs="f0004">6a</figref> is provided an electrical coupling 18th This generally takes place via line connections by the data from the individual sensor 9.1 to 9.n to a corresponding read-out unit 19 and / or data collection and / or evaluation device 20 are passed, which performs the function of data processing. The data acquisition and / or evaluation device 20 may be formed by a control and / or regulating device 21, an evaluation 22, for example in the form of a PC.

p0042The <figref idrefs="f0004">figure 6b</figref> illustrates an embodiment in contrast with wireless data transmission. Thereby, the number of dangling and disturbing lines are avoided. For this purpose, the individual piezoelectric sensors 9.1 to 9.1n or 9.21 to 9.2n a measuring beam 14.1, 14.2 at least one transmission device 23.1, assigned to 23.2, over which the data from the piezoelectric sensors 9.1 to 9.n of a measuring beam 14.1, 14.2 to a receiving means 24 are directed or sent. The receiving device 24 may be implemented multiform. This may be a separate receiver, a deal with an evaluation, a control and / or regulating device, a PC can be coupled receiving device 24 or can be integrated into this receiving device, for example, integrated interface 25th

p0043According to a particularly advantageous embodiment, each of the individual piezoelectric sensors is 9.1 to 9.n. assigned its own transmitter. This enables accurate assignment of data specifically related to the specific arrangement and location of a single piezoelectric sensor and the acting in this area contact pressure and / or pressure.

p0044In the <figref idrefs="f0001 f0002 f0003 f0004">Figures 1-6</figref> the piezoelectric sensors 9.1 to 9.n are each as essentially carried round structures whose dimensioning thus lying in two in a plane (XY plane) perpendicular directions are dimensioned substantially equal. However, it is specifically possible to use the sensors 9.1 to 9.n form as elongated shapes, which are thus dimensioned differently in their two orthogonal directions of extension. Such trained sensors 9.1 to 9.n. may be present as elongated rounded or oval shapes as well as elongated right-or polygonal shapes.

p0045If the sensors 9.1 to 9.n. elongated shape, they may have different or the same orientations relative to each other and occupy relative to the direction of extension of the scraper blade. 2 Since a maximum signal can be obtained when the direction of extension of the sensors 9.1 to 9.n. is substantially parallel to the X-direction and machine-direction and perpendicular to the direction of the doctor blade 2, an array of sensors 9.1 to 9.n. is recommended under a non-zero angle α between the longitudinal extent of the sensors 9.1 to 9.n and the longitudinal extension of the doctor blade 2. the angle α should thereby be as large as possible, preferably more than 45 °, are approximately 90 ° in the best case, when the sensors 9.1 to 9.n. or coupling lines or other technical limitations, eg in terms of the space allow.

p0046Preferably, the sensors are 9.1 to 9.n thereby parallel to each other, since the signal outputted from a sensor 9 varies due to its alignment with non-round shape. A parallel arrangement is thus preferred, as each sensor 9.1 to 9.n then provides a comparable signal; however, it is also possible for the sensors 9.1 to 9.n rearranging and reconcile the different signals by a suitable calibration or software in the evaluating 22nd

p0047Incidentally, the embodiments described above, which portions 17, scraper blade parts 2.1 to 2.n or recesses 15 different spacings of the sensors 9.1 to 9.n remain include and among each other and relative to one to the blade extension etc., from the shape of the sensors 9.1 to ninth n unaffected. In particular, the individual features of the exemplary embodiments can be combined to measure any according to the requirements.

p0048The individual measuring beams can be arranged in the arrangement in a scraper device 1 spaced apart. In a doctor device an over the length of one piece running blade is preferably used to ensure a uniform space between the blade and the surface over the width of the movable surface. This corresponds to the embodiment of<figref idrefs="f0001">figure 1b</figref>, The arrangement of piezoelectric sensors 9.1 to 9.n. preferably takes another at a constant distance. Also conceivable, however are variable distances in length direction of the blade.

p0049Since the environment in which the doctor blade and doctor devices described are used, are charged high mechanical and chemical, may in particular relate to the data acquisition and evaluation device 20 and to the control and regulating device 21 leading line connections and provided with sensor areas for scraper or doctor blade to be fully or partially protected by a suitable cover or enclosure.

<u>LIST OF REFERENCE NUMBERS</u>

p0050<dl id="dl0002" compact="compact"><dt>1</dt><dd>scraper device</dd><dt>2</dt><dd>scraper blade</dd><dt>2.1 - 2.n, 2.1-2.5</dt><dd>Scraper blade parts</dd><dt>3</dt><dd>blade holder</dd><dt>4</dt><dd>support means</dd><dt>5</dt><dd>Means for pressing</dd><dt>6</dt><dd>A movable surface</dd><dt>7</dt><dd>end</dd><dt>8th</dt><dd>Means for at least indirect detection of the pressing force and / or the pressure at least indirectly characteristic</dd><dt>8.1 - 8.n</dt><dd>splitter</dd><dt>9, 9.1 - 9.n.</dt><dd>piezoelectric sensors</dd><dt>9:11, 9:21, 9:22, 9.31-9-3n, 9:41, 9:42, 9.5</dt><dd>piezoelectric sensors</dd><dt>10</dt><dd>Blades top</dd><dt>11</dt><dd>Blade base</dd><dt>12</dt><dd>Anstellbereich</dd><dt>13</dt><dd>blade end</dd><dt>14.1 - 14.n</dt><dd>measuring beam</dd><dt>15:11 to 15:32</dt><dd>recess</dd><dt>16.1 - 16.3</dt><dd>carrying region</dd><dt>17.1, 17.2</dt><dd>Area</dd><dt>18</dt><dd>electrical coupling</dd><dt>19</dt><dd>readout unit</dd><dt>20</dt><dd>Data acquisition and / or evaluation</dd><dt>21</dt><dd>Control and / or regulating device</dd><dt>22</dt><dd>evaluation</dd><dt>23.1, 23.2</dt><dd>transmitting device </dd><dt>24</dt><dd>receiver</dd><dt>25</dt><dd>interface</dd><dt>a</dt><dd>distance</dd><dt>a₁</dt><dd>distance</dd><dt>a₂</dt><dd>distance</dd><dt>b₆</dt><dd>Width of the movable surface</dd><dt>c</dt><dd>distance</dd><dt>c₁</dt><dd>distance</dd><dt>c₂</dt><dd>distance</dd><dt>I, I₂</dt><dd>length</dd><dt>I_2.1 I_2.2, I_2.3 I_2.4 I_2.5</dt><dd>length</dd><dt>I_13.1, I_13.2</dt><dd>length</dd></dl>