The present patent application relates, in accordance with a first aspect, to an apparatus for the application of adhesive onto the surface of a substrate or workpiece.

It is desired, for example, in the field of the automotive industry to provide predetermined workpieces, such as motor vehicle interior compartment trim parts, with adhesive tracks, with the result that a covering, such as a decorative material, can be adhesively bonded on the workpiece or carrier subsequently with the aid of said adhesive tracks.

Here, it is well known from the prior art that carrier parts or workpieces are guided along below stationary non-tiltable adhesive dispensing apparatuses. This is also not a problem, in particular, in the case of homogeneous, substantially flat, horizontally arranged workpieces .

As soon as workpieces of this type, such as carriers, have certain 3D profiles, however, an adhesive application of this type proves to be less suitable, since, for example, regions of the carrier with a noticeable slope receive the same quantity of adhesive as an equally wide (as viewed from above) but horizontally oriented region. It can be easily comprehended on the basis of geometric considerations that the first-mentioned region subsequently has a lower adhesive application density than the second region.

Since this is fundamentally undesired, efforts are known from the prior art, furthermore, to arrange adhesive dispensing heads in a movable manner, for example on robot arms, it then being possible for the adhesive dispensing head to move over the carrier element or workpiece along tracks. In regions which are oriented obliquely or are provided with a slope, the adhesive dispensing head can be tilted, in order to assume a substantially orthogonal orientation with respect to the workpiece section to be treated, and therefore to apply the adhesive onto the workpiece such that it strikes it in a substantially orthogonal manner, even in the non horizontal regions. The last-mentioned procedure opposes the fundamental aim, however, for simple tracks or paths of the adhesive head, which preferably should ideally have no real tilting movement of the head, also in order to save time. It is therefore an object of the present invention, proceeding from the described prior art, to provide an apparatus for the advantageous application of the adhesive, precisely in the case of profiled workpieces or substrates.

The invention achieves said object in accordance with a first aspect having the features of patent claim 1, in particular having those of the characterizing part, and is accordingly distinguished by a sensor device for the determination of a profile of a region (of the surface) of the workpiece or substrate, in particular a region which is assigned to the dispensing nozzle.

In other words, the concept of the invention therefore consists in providing an apparatus with means which can detect the topography (of the surface) of the substrate or workpiece, in particular in order for it to be possible for said data to then be taken into consideration during the dispensing of the adhesive, for example with the aid of a controller.

In this context, for example, the quantity or the volumetric flow of the adhesive can be adapted to the detected topography or the detected profile: a flat or horizontally oriented region of the surface of the substrate or workpiece is thus fundamentally to be wetted with less adhesive than a (dispensing) region which has a certain profile and at any rate a profile which differs from a horizontal orientation. This simply has to do with the fact that the second-mentioned region has a greater substrate or workpiece surface area which should be assigned more adhesive for a homogeneous application pattern .

The result of the measurement of a profile can also be taken into consideration in some other way, however, than with regard to the adhesive quantity to be dispensed or the volumetric flow: very generally, an application parameter can thus namely be ( re- ) calculated which does not have to have anything directly to do with the adhesive. The application parameter can also relate, for example, to another fluid, for example the spray air (and its volumetric flow) or the like. Other properties of the adhesive instead of the volumetric flow or the quantity can also fundamentally be capable of being manipulated on the basis of the measurement according to the invention (for example, the temperature) .

The profile can be determined or detected by way of a sensor device. Here, the term "profile" does not necessarily relate to an absolutely identical mapping or determination of the actual topography of the surface, but rather said term also includes merely an approximation: in a simplest case, the sensor device can thus determine, for example, two edge points of a profile, in order to perform a simple linear approximation in the region which is arranged between said two edge points. In other words, an average slope can be measured in said region in this depicted exemplary case, and therefore the actual surface of the substrate or workpiece in the region can be approximated. Here, the value which is determined in this way is naturally not absolutely accurate, but is more accurate than the assumption which is made without utilization of the sensor device (namely that this is a horizontally oriented surface) .

It goes without saying, however, that the sensor device can also determine a very much more accurate profile, for example by way of the detection of the plurality of points along a profile or even by way of a stepless detection of (all) points along the profile. Here, depending on the sensor type, different methods for the determination of the profile can be used which are all included in the present invention.

Here, the sensor device has at least one sensor, preferably at least two. Here, the sensor or sensors can advantageously measure the spacing between the sensor and one or more points in the region of the substrate or workpiece. Since the precise arrangement of the sensor or the sensors on an apparatus is known, conclusions can be made in this way about the profile in said region.

The measured region of the substrate or workpiece can be, in particular, linear or else, depending on the definition, three-dimensional. Here, the region is typically understood to mean the region between two edge profile points of a linear profile.

The detection of the entire three-dimensional topography also belongs to the determination of a profile in the context of the present invention, however.

In particular, a case can also be subsumed under the designation of "region" of the substrate or workpiece, in which case the region comprises the entire substrate or the entire workpiece. The term "region" is advantageously to be understood, however, in the sense of "part" of the substrate or workpiece. In particular, the width of a region is understood to mean the width in plan view or from above.

The sensor device is preferably arranged captively or fixedly on (the body of) the apparatus, in particular on an application head of the apparatus. In particular, the sensor device is mounted fixedly on the body. It can certainly be adjustable, however, for example rotatable or pivotable. In this context, the sensor device or the sensor or the sensors is/are fastened to (the body of) the apparatus captively, movably or immovably.

Here, the sensor device advantageously moves together with the application head of the apparatus, in particular for the case where the application head is arranged on a robot arm.

In the last-mentioned case, for example, the apparatus or its application head can be guided along over the surface of the substrate or workpiece, preferably along tracks which are predefined or are to be predefined. As an alternative, however, it is also conceivable that the apparatus, in particular the application head, is mounted in a stationary manner, and the substrate or workpiece is guided along past the apparatus or below the latter.

Here, the substrate or workpiece and the apparatus are typically oriented with respect to one another in such a way that the at least one dispensing nozzle of the apparatus points (preferably orthogonally) toward the substrate or workpiece, and the substrate or workpiece is consequently arranged in the dispensing direction of the dispensing nozzle. The adhesive can then be dispensed onto the substrate or workpiece by the apparatus. Here, this can be, in particular, a spray process, the adhesive being applied onto the substrate or workpiece, for example, with the aid of spray air. Here, the adhesive can be dispensed in an oscillating manner (preferably in one plane) .

The sensor device is (or its sensors are) preferably oriented substantially in the same way as the dispensing nozzle or the dispensing nozzles. They therefore point, in particular, in the direction of the substrate or workpiece .

The adhesive dispensing apparatus is preferably a spray dispensing system which does not make contact, such as an adhesive spraying apparatus. Adhesive of this type is typically discharged from a corresponding adhesive dispensing nozzle or adhesive dispensing opening (preferably with the aid of forming air) , in order for it to be able to be oscillated, for example, in one plane in the manner of a filament.

The material which is to be applied or is to be sprayed is adhesive, in particular a highly viscous medium. What are known as hot melts or hot melt adhesives are typically sprayed, which are heated beforehand in a heating device which is assigned to the apparatus. Said hot melt adhesives are considered to be particularly reliable, such as PUR adhesives or POR adhesives.

A typical melt adhesive can be based, for example, on polyurethanes and, during the use or application, can react with atmospheric humidity to form a cross-linked polyurethane with a high molar mass.

Reactive melt adhesives of this type solidify upon cooling and in the process permit rapid production and adhesive bonding processes, in particular without preceding drying of the adhesive. Said adhesive can optionally also be reactivated again with the aid of IR radiation . An apparatus which can apply hot melt adhesive in a spraying manner can also be called a melt blowing apparatus, and a corresponding method can be called melt blowing .

Each adhesive outlet opening or each nozzle of the apparatus is typically assigned a valve which can be capable of being closed and opened, for example, by a needle. It goes without saying that a nozzle (with a valve) can be assigned a plurality of adhesive outlet openings .

It is also to be noted that an adhesive dispensing system according to the invention or an apparatus according to the invention can be achieved in a particularly elegant manner by way of retrofitting of existing adhesive dispensing apparatuses: thus, for example, an existing adhesive dispensing apparatus of the prior art can be improved simply by way of the subsequent installation of a corresponding sensor device. To this end, new installation points can be provided on the apparatus, or a completely new system can be provided, in the case of which there are installation points for optionally available sensor devices (the same applies to electric connectors and/or data connectors) .

A relative movement of the nozzle and the substrate or workpiece typically takes place during the application process. The workpieces can be, for example, (plastic) shaped parts and/or can also be smooth and/or convex surfaces (typically without cavities, but certainly with recesses ) .

The substrates or workpieces can be, for example (but not exhaustively) , workpieces from the automotive field or the car industry, in particular interior compartment trim parts or the like which, for example, have to be provided with decorative elements or decorative surfaces. The hot melt adhesive is particularly suitable for this purpose.

For example, 3D carriers from the automotive field are included, such as carriers in the case of door trim panels, trunk trim panels, consoles, dashboards and the like. They can certainly have relevant relief differences. The adhesive is therefore also applied in tracks, and the substrate or workpiece typically experiences a relative movement with respect to the apparatus or with respect to the (spray) nozzles or adhesive outlets.

The apparatus is typically an application apparatus which can comprise, for example, one or more application heads, an application head typically being assigned a plurality of nozzles. The application head can also comprise a pumping station for the adhesive, heating elements and the like. The entire apparatus can be arranged, for example, on a robot arm or can have a corresponding robot arm. In this context, the main claim requires that there is at least one dispensing nozzle (there can of course also be precisely one, however) .

The apparatus can also comprise a supply of adhesive or can be connected to a supply of this type.

That "region" of the substrate or workpiece which is cited in the main claim is, in particular, a region which is assigned to the dispensing nozzle. Therefore, substantially a region which can be reached by the dispensing nozzle in at least one place or position and/or can be wetted or loaded with adhesive is meant. In particular, "region" can in each case mean a region of equal width with regard to the orientation of the dispensing nozzle and/or sensor device, it then being possible for the substrate or workpiece in said region to have a different surface size and/or length on account of a different profile or a different topography.

In accordance with one advantageous refinement of the invention, the sensor device has a distance sensor. A sensor of this type is capable of measuring a distance, in particular the distance between the sensor device and/or the apparatus or the dispensing nozzle and the substrate or workpiece (or the surface thereof) . This is preferably an optical distance sensor. It can also be any other type of sensor, however, which is capable of measuring a distance. It can be, in particular, a laser sensor, that is to say a sensor which emits one or more laser beams and detects their reflection, in particular in accordance with a triangulation method.

In accordance with a further advantageous refinement of the invention, the sensor device has a plurality of distance sensors. As a result, the sensor device can determine, for example, a plurality of points, for example edge points, of a linear profile. The distance sensors can be, in particular, the abovementioned laser sensors. Each of the laser distance sensors can then, for example, emit and detect a laser beam.

There are advantageously at least two distance sensors, for example in order to measure the edge points of a profile. It goes without saying, however, that there can also be more than two distance sensors, for example in order to measure a plurality of profiles at the same time or else in order to measure more points on one profile.

In accordance with one particularly advantageous refinement of the invention, the sensor device has a laser scanner. The latter can be used for the determination of the profile, for example by said laser scanner projecting a laser line onto the surface to be measured of the substrate or the workpiece. In particular, a sensor matrix can then be included, on which the diffusely reflected light of the laser line is mapped. A laser scanner of this type is also called a profile sensor or a laser line triangulator . In particular, the triangulation principle can accordingly be used for the two-dimensional profile detection on a very wide variety of object surfaces. Here, for example, a laser beam is widened to form a static laser line via a special optical system, and is projected onto the measuring surface. The receiving optical system of the laser scanner can then map the diffusely reflected light of said laser line onto said sensor matrix. The laser scanner can already integrate a controller or a control device or can cooperate with the existing controller of the system.

A laser scanner of this type additionally has the advantage that even 3D measured values can be detected (in particular, continuously) in the case of a relative movement between said laser scanner and the substrate or workpiece .

The apparatus according to the invention advantageously has a controller which adapts an application parameter under consideration of the determined profile of the region. Here, the controller can receive data from the sensor device and, proceeding from the data which are received in this way, can adapt and/or recalculate an application parameter and then forward it, for example to the application head or to a body of the apparatus which, in particular, can also comprise a volumetric pump .

An application parameter which is adapted in this way can be, for example, a volumetric flow of the adhesive to be dispensed or the spray air to be dispensed or the like. In particular, a homogeneous application of adhesive on the substrate or workpiece can therefore be achieved on the substrate or workpiece, depending on the determined profile, via the adaptation of the application parameter by way of the controller. If there is namely a profile with an overall greater surface area on the measured region of the substrate or workpiece, more adhesive has to be dispensed into the region than into a region with a homogeneous profile.

In particular, the application parameter relates to the adhesive to be dispensed. Therefore, in particular, the quantity per unit time of adhesive to be dispensed can be adapted or else, for example, the temperature of the adhesive can be manipulated or the like.

In accordance with one particularly advantageous refinement of the invention, the apparatus has a delivery pump for the adhesive, which delivery pump can be switched in a manner which is dependent on the measured results of the sensor device. Said switching can be carried out or initiated by the abovementioned controller. The delivery pump is, in particular, what is known as a volumetric delivery pump, in particular a gear pump or the like.

A delivery pump can be integrated into the apparatus, in particular into the application head. A connecting channel, in particular a rigid channel (that is to say, not in the manner of a hose or the like) , advantageously exists from the delivery pump to the dispensing nozzle. This has the advantage that the delivery pump can supply the dispensing nozzle with adhesive without considerable time and/or inertia losses (as in the case of a hose, for example) .

It is to be noted at this point that it goes without saying that the apparatus can also have more than one delivery pump, for example two or three or even more delivery pumps. In this context, a delivery pump can be assigned to a plurality of dispensing nozzles or a group of dispensing nozzles and can supply them with adhesive. As an alternative, however, each dispensing nozzle can also be assigned precisely one delivery pump in one particularly preferred embodiment case. For the case, in particular, where more than only the edge points are known in the profile, the delivery pumps can also in this way be actuated in accordance with measured topography sections .

It is advantageously provided according to the invention that the sensor device is arranged captively on the apparatus. This means that the sensor device can therefore be arranged substantially fixedly on the apparatus, in particular in an immovable manner. A fastened, movable arrangement can also be selected, however, with the result that the sensor device can still, for example, be adjusted manually, in particular pivoted, or the like, even in an assembled position. Here, the sensor device is preferably arranged on the application head. This has the advantage that the sensor device is moved together with the application head, on which the nozzles are typically also arranged.

In accordance with a further advantageous refinement of the invention, the sensor device is arranged in a leading manner with regard to the dispensing nozzle. This means, for example, that the sensor device is arranged upstream of the dispensing nozzle or nozzles in the track direction in the case of a movement along a track over the substrate or the workpiece. There is therefore an offset .

If, in contrast, the substrate or workpiece is guided along below a (stationary) sensor device (along a conveying direction) , although the sensor device is arranged downstream of the dispensing nozzle in the conveying direction, it is arranged in a leading manner with regard to the latter, since a region of the substrate or workpiece which is to be provided with adhesive is first of all guided along below the sensor device and only subsequently reaches the dispensing nozzle. In this context, it is important that the region of the substrate or workpiece which is to be provided with adhesive first of all experiences an allocation to the sensor device before it experiences an allocation to the dispensing nozzle, in particular in order that an on-the-fly measurement and adaptation of an application parameter becomes possible.

In accordance with a last advantageous aspect of the invention, the sensor device configures a projection device for the simulation of the adhesive dispensing behavior of the adhesive dispensing apparatus with the aid of a light structure which can be projected onto the substrate or workpiece by the projection device. This configuration affords the advantage that, in particular, an optical sensor can likewise be used as a projection device. In other words, the actual application of adhesive for a calibration can be replaced by a light structure for the purpose of optical testing. In this way, wastage of material, in particular of set-up parts and adhesive which is dispensed during the calibration, can be reduced or completely avoided. Therefore, during the calibration or configuration or set-up of the corresponding application track or tracks on the substrate or workpiece, the user can detect on the basis of the light structure where adhesive will subsequently (while the corresponding tracks are being moved along) be applied onto the substrate or workpiece.

It can advantageously be provided here that the light structure is emitted from approximately the same position at which the actual adhesive is dispensed later, during the actual application operation. To this end, in particular, a system can be provided, in the case of which the nozzle or nozzles is/are replaced by one or more sensor devices. For this purpose, the nozzles and the sensor devices can provide, for example, identical or the same installation means. In particular, the sensor device can therefore be capable of being installed on the apparatus instead of a nozzle. Other exemplary embodiments are fundamentally also possible, however, in the case of which a sensor device configures a projection device and can be installed in the apparatus in addition to the nozzles.

In accordance with a second aspect of the invention, the object which is set is achieved by way of a method as claimed in claim 10, and is distinguished, in particular, by the following steps:

• determination of the profile of a region of the substrate or workpiece, in particular by way of a sensor device,

• determination of an application parameter, in particular an (adhesive) volumetric flow which is to be dispensed onto the region, with consideration of the determined profile of the region,

• dispensing of adhesive into the region of the surface with consideration of the application parameter .

In particular, the above-described apparatus according to the invention can be used to carry out a method of this type.

With regard to the method as claimed in patent claim 10, it is noted that embodiments and advantages which are described in conjunction with the preceding device claims 1 to 9 and in the description of the figures are also to be considered to be disclosed in an identical manner in conjunction with said method. Therefore, the repetition of all the abovementioned exemplary embodiments and advantages and those which will be mentioned later is to be dispensed with at this point merely for reasons of clarity of the application.

For example, the method according to the invention is also to include methods of the type, in the case of which (optical) distance sensors, in particular laser sensors, or else laser scanners are used, in the case of which the apparatus has at least one, in particular volumetric, delivery pump for the adhesive, which delivery pump is switched in a manner which is dependent on the measured results of the sensor device, namely preferably by a controller which is connected to the delivery pump and the sensor device, in the case of which sensors or scanners the sensor device is arranged in a leading manner with respect to the dispensing nozzle and therefore measures a region before the dispensing nozzle dispenses adhesive onto said region, or in the case of which sensors and scanners the sensor device configures a projection device and, in particular, can be swapped for a nozzle.

Laser light or else any other (visible or invisible) light can advantageously be used for the method according to the invention, but also for the apparatus according to the invention.

The method typically proceeds temporally in such a way that first of all the sensor device measures or determines a profile of a region or substrate or workpiece, subsequently forwards the measured information to a controller, and said controller can subsequently determine or adapt an application parameter. The controller then forwards the application parameter (preferably in the form of control signals) to other parts of the apparatus, for example to a (volumetric) delivery pump or the like. Further advantages and refinements of the invention result using the subclaims which have not been cited and using the description of the figures which now follows and in which: fig . 1 shows a greatly diagrammatic front view of a first exemplary embodiment of an apparatus according to the invention having four adhesive dispensing nozzles, relating to a body section of the apparatus, which body section is shown on its own for improved clarity, but also without corresponding connectors, etc., having two exemplary laser distance sensors which scan two edge profile points of a curved workpiece, fig. 2a shows a view approximately in accordance with a view arrow Ila in fig. 1 of the apparatus according to fig. 1 in a purely diagrammatic side view, in particular in order to clarify the triangulation method which is carried out by the laser distance sensors, fig. 2b shows the apparatus according to fig. 1 and fig. 2a in a diagrammatic oblique view, fig. 3 shows an enlarged, truncated illustration of the region labeled by the designation III in fig. 1 with an additional illustration of an approximated linear profile, fig . 4 shows a greatly diagrammatic oblique view of a second exemplary embodiment of the invention, comprising a laser scanner which scans the workpiece which is known from the first exemplary embodiment in a linear manner, fig. 5 shows the same apparatus in a view according to fig. 4 during the scanning of an alternative workpiece, fig . 6 shows a purely diagrammatic front view

(approximately in accordance with view arrow VI in fig. 5) of the second exemplary embodiment in order to clarify the surface conditions in a workpiece region which corresponds approximately (but not precisely) to that according to fig. 5, with a purely diagrammatic illustration of the four nozzles, and fig. 7 shows two highly diagrammatic oblique views of a third exemplary embodiment of the present invention, in the case of which the four dispensing nozzles can be dismantled according to fig. 7a and can be replaced by one or more sensor devices according to fig. 7b.

It is to be noted before the following description of the figures that identical or comparable parts are possibly provided with identical designations, partially with the addition of small letters or apostrophes. In the patent claims which follow the description of the figures, the designations which are used in the figures and the description of the figures are possibly used (partially) without apostrophes or small letters for the sake of simplicity, at any rate in so far as the corresponding subjects are comparable.

In the figures, fig. 1 first of all shows an apparatus 10 according to the invention or a part thereof, the apparatus 10 being configured as an adhesive dispensing apparatus, more precisely as an adhesive spraying apparatus . According to fig. 1, the apparatus 10 is assigned to the surface 11 of a workpiece 12 (shown merely in sections or in a broken-away manner) . It can load the workpiece with adhesive 13, which adhesive is shown in fig. 1 merely by way of example as an adhesive element 13 (the vertical is shown merely for the purpose of reference) .

In fig. 1, said adhesive filament 13 is depicted in an oscillating or swaying manner in one plane, which plane is defined by an application direction A and a transverse direction Q.

Here, the adhesive filament 13 can receive its oscillating shape, for example, from spray air which is dispensed by way of the apparatus 10.

Here, both said spray air and the adhesive 13 can exit from a nozzle 14, for example the nozzle 14a which is shown .

In the exemplary embodiment which is shown in fig. 1, the application head 15 of the apparatus 10 is assigned four nozzles 14a, 14b, 14c, 14d by way of example here. Said nozzles 14 are typically mounted fixedly on the application head 15.

It is noted merely for the sake of completeness that it goes without saying that each of the adhesive dispensing nozzles 14a, 14b, 14c, 14d can dispense adhesive filament 13. For the sake of clarity, fig. 1 shows this merely for one of the nozzles, namely the nozzle 14a.

On the front side 16 (shown in a front view in fig. 1) of the application head 15, in each case one switching valve 17 and one corresponding directional valve 18 for each nozzle 14 are also arranged in addition to the nozzles 14. According to the invention, in accordance with fig. 1, the application head 15 is additionally assigned a sensor device 19, comprising two laser distance sensors 19a and 19b.

In accordance with fig. 1, the application head 15 can be arranged on a base part 20 of the apparatus 10, in such a way that the application head 15 can be, in particular, height-adjustable or movable, for example as a result of the arrangement on a holding part 21 of the apparatus 10. The holding part 21 can then be arranged on further elements (not shown) of the apparatus 10, such as a robot arm or a gantry or the like.

It is also to be noted that the apparatus 10 can also have a controller 22 (shown in a merely completely abstract manner in fig. 1) which can communicate via connecting means (not shown) , such as cables or else a wireless connection, to the application head 15, in particular to the sensor device 19.

A volumetric delivery pump which is arranged in the interior of the apparatus 10, in particular in the interior of the base part 20, is also not shown in the figures (in particular, fig. 1), which delivery pump can regulate or deliver that volumetric flow of the adhesive which exits from the nozzles 14a, 14b, 14c, 14d. A delivery pump of this type can also be linked or connected to the controller 22. Here, each nozzle 14a, 14b, 14c, 14d can be assigned a dedicated volumetric delivery pump. As an alternative, a plurality of nozzles 14a, 14b, 14c, 14d can also be supplied by one volumetric delivery pump.

Fig. 1 has already illustrated that the sensor device 19, or each laser distance sensor 19a, 19b, can direct a laser beam 23a, 23b onto the surface 11 of the workpiece 12. The side view according to fig. 2a which corresponds approximately to a view along the view arrow Ila in fig. 1 then clarifies that said laser beam 23 can naturally be reflected by the surface 11 of the workpiece 12 and can be detected by a receiver (not shown) in the interior of the corresponding sensor 19a, 19b (fig. 2a shows merely the laser distance sensor 19b for reasons of geometry) . The sensor device 19 and the laser distance sensors 19a, 19b therefore operate in accordance with the well known laser triangulation method. This makes it possible to determine the distance between the corresponding laser distance sensors 19a, 19b and in each case one point P on the surface 11 (which the laser strikes ) .

In addition, the further construction of the application head 15 can be gathered from fig. 2a: the application head 15 thus has, in particular, a lower gas block 24 and an upper adhesive block 25 in the rear region, that is to say the region which faces away from the end side 16, which blocks together represent the main body of the application head 15. Here, both the gas block 24 and the adhesive block 25 are in each case assigned electric connectors 26 and 26', respectively.

In addition to the electric connector 26, a switching connector 27 and an adhesive connector 28 are also arranged, for example, on the application head 15 in the rear region which faces away from the end side 16, which switching connector 27 and adhesive connector 25 can supply the application head 15 with compressed air and adhesive, respectively. All of the connectors in the figures which are shown are not provided with corresponding mating connectors or supply connectors merely for reasons of clarity. In particular, the illustration of the adhesive filament according to fig. 12 is therefore to be understood to be merely diagrammatic . Fig. 2b then mixes the perspectives according to fig. 1 and fig. 2a for reasons of improved clarity to form an isometric oblique view.

The method of operation of the apparatus 10 in accordance with the first exemplary embodiment is now to be described using fig. 3 which discloses an enlarged illustration, in particular, of the application head 15 (approximately in a region which is shown in a box in fig. 1 and is provided with the designation III) :

The distance sensors 19a and 19b can thus in each case determine a spacing from the surface 11 of the workpiece 12 either during running operation (that is to say, during adhesive dispensing) or, as an alternative, in a calibration method step (that is to say, for example, during the fixing of a track to be traveled, but still without adhesive dispensing) .

The respective spacing of the respective sensor 19a, 19b from the surface 11 is denoted by hi and h ₂ , respectively, in fig. 3. In other words, the sensor 19a can measure spacing hi from a first profile edge point Pi on the surface, and the second sensor 19b can measure a spacing h ₂ from a second profile edge point P ₂ on the surface 11. Here, said two points Pi and P ₂ delimit a region B of the body 12, for which region a profile is to be determined, in particular is to be approximated.

The example can be gathered from fig. 3 where the spacing of the sensor 19a from the point Pi is smaller than the spacing between the sensor 19b and the point P ₂ (in other words, hi is smaller than h ₂₎ .

This difference can also be called h and essentially represents the height difference in the region B of the workpiece 12. The mean slope in the region B can then be determined, for example, from said value h and the known width b of the region B, or an approximated profile in the manner of a straight line G (which represents the hypotenuse in the right-angled triangle G, h, b) .

It can be seen clearly from fig. 3 on account of geometric considerations that the approximated linear profile G is longer than the width b of the region B, with the result that, in particular, the adhesive volumetric flow which is to be dispensed by the apparatus 10 (or the head 15) can be adapted or increased, in order that more adhesive can be applied onto the actual surface 11 of the workpiece 12 in the region B. This promotes the homogeneous application of adhesive, since merely only the non- adapted base volumetric flow of adhesive then actually needs to be dispensed on horizontal regions of the workpiece 12. With regard to fig. 3, a base application of adhesive would therefore be based on the quantity for a horizontal region of the width b.

In view of fig. 3, it can be readily comprehended that the approximation by way of the straight line G is actually an improved adaptation to the actual topography in the region B, and that, in the case of knowledge of the actual, non-straight but rather curved surface 11, a certain additional application would still be necessary, however, in order to also take into consideration the actual curvature of the topography in the region B (a curve generates a greater surface area than a straight section) .

Finally, it is to be noted with regard to fig. 3 that the method which is shown is the approximation of the topography using a linear profile. Said measurement can take place continuously or at any rate cyclically, however, in or opposite to the conveying direction F (or track direction) , with the result that a plurality of approximated profiles can be produced and a more or less continuous adaptation can take place in the case of a relative movement between the workpiece 12 and the apparatus 10.

It is to be noted merely for the sake of completeness, in particular in relation to fig. 2a, that the conveying direction F is typically understood to mean that direction, in which the substrate or the workpiece 12 would be guided along below the apparatus 10, whereas the track direction B is understood to be that direction which is, in particular, opposite to the former and along which the apparatus 10 would have to be guided in a track over the (in particular, stationary) workpiece.

Fig. 4 shows a second exemplary embodiment of an apparatus 10' according to the invention. Here, essential elements of the apparatus 10' correspond to those of the apparatus 10 according to figures 1 to 3, and said apparatus 10' is assigned, in particular, to the same workpiece 12 with the same surface 11 according to fig. 4.

The essential difference between the apparatuses 10 and 10' according to fig. 4 relates to the sensor device 19' which, contrary to the first exemplary embodiment, no longer consists of two separate distance sensors, but rather is configured as an integrated laser scanner 19' .

A laser scanner 19' of this type is also called an LLT or a laser line triangulator and has, in particular, a line optical system in its interior for emitting a fan like laser beam. In the rear receiving region, the laser scanner 19' then typically has a receiving optical system and a corresponding sensor matrix. The latter make the mapping or the recording or determining of what is known as a linear profile by way of the recording of the (mapped) laser line 29 possible. Therefore, the height or the topography is also determined here (in particular, in accordance with the triangulation method) but, in contrast to the first exemplary embodiment, not of merely two separate points, but rather more or less of the entire region B. In other words, a continuous profile is detected (even if merely a limited number of points are likewise mapped here on account of the digital mapping on the matrix; this allows a very much higher resolution, however, than the merely two points of the first exemplary embodiment) .

In contrast to the first exemplary embodiment, a profile in accordance with a laser line 29 in fig. 4 can therefore be gathered from this exemplary embodiment, which laser line 29, in a deviation from the straight line G in accordance with the first exemplary embodiment, then maps a realistically curved surface topography which can also be evaluated or utilized by a corresponding controller 22.

As a result of the more accurate mapping of the actual topography, the apparatus 10' can therefore determine a more improved measurement of the deviation of the length of the profile from the actual width b of the region B. In other words, the apparatus 10' then determines that even more adhesive actually has to be applied to the region B than the evaluation by way of the apparatus 10 in accordance with the first exemplary embodiment indicated. This is due to the fact that the approximation is then much more precise than the linear approximation in accordance with the first exemplary embodiment.

A further important special feature of the second exemplary embodiment 10' can likewise be seen in fig. 4: the sensor device 19' is thus arranged considerably upstream of the dispensing nozzles 14 in the track direction B. This offset is labeled by V in figure 4 and makes, in particular, what is known as an "on-the-fly measurement" possible, in the case of which the apparatus 10' can at the same time carry out the determination of the profile during the traveling along a track for the application of adhesive, since a certain computing time and also mechanical inertia (for example, in order to adapt the pump speed) is to be taken into consideration for the determination of the profile and, in particular, for the subsequent adaptation of the application parameter (for example, the volumetric flow of the adhesive which is to be dispensed) .

In other words, the sensor device 19' can already move over a region B and determine (or approximate) its profile while the nozzle 14 is still dispensing adhesive to a second region, for which the apparatus 10' has already previously determined or approximated a profile.

Fig. 5 shows the apparatus 10' in accordance with the second exemplary embodiment in a view according to fig. 4 for another workpiece 12' (or, as an alternative, another region of the workpiece 12) with a surface 11' . Here, said workpiece 12' is merely to clarify that it can be determined for a region B' by way of the measurement by way of the sensor device 19' that said region B' (which also has the width b) actually requires even more adhesive, although the edge profile points Pi and P _å are the same as in the case of the region B of the workpiece 12 according to fig. 4.

Here, the surface 11' to be loaded is simply even greater, since the surface 11 bends not only in one direction, but rather has a plurality of inflection points in the sectional profile.

It would be even less possible to approximate a topography of this type by way of the apparatus in accordance with the first exemplary embodiment (according to figures 1 to 3) than the topography of the workpiece 12 according to fig. 4. This is clarified, for example, by the very abstract illustration according to fig. 6 which first of all depicts how the approximated linear profile G' would have looked by way of an apparatus in accordance with the first exemplary embodiment. Here, said first approximation G' already has a certain extra length 1 which would require additional adhesive in comparison with an application onto a purely horizontal surface of width b. Here, fig. 6 clarifies, furthermore, that, in addition to the extra length 1, there is a second extra length 1' which is explained by the deviation of the actual topographical form from the straight line G' . It can therefore be observed that it can be determined by way of the apparatus 10' in accordance with the second exemplary embodiment that a predefined region of a region width b actually requires considerably more adhesive, based on an extra length 1 + 1', than if the region had no profile (or were horizontal) .

The apparatus 10' in accordance with the second exemplary embodiment is therefore considerably more suitable for a challenging topography, even if it has to be noted that the apparatus 10 in accordance with a first exemplary embodiment is easier to maintain, to calibrate and to assemble and, moreover, as a rule requires less computing time. Accordingly, recourse can be made to one of the two systems depending on the application case.

Finally, fig. 7 shows a third exemplary embodiment 10'' of an apparatus according to the invention, in each case only the already known application head 15 being shown in the two illustrations 7a and 7b for the sake of clarity. Said application head does not differ substantially from the application heads 15 in accordance with the other exemplary embodiments with the exception of the arrangement of the sensor device.

Fig. 7a first of all clarifies that the nozzles 14 can be removed or disassembled from the end side 16 of the application head 15. To this end, for example with the aid of a tool (not shown) , an installation means, such as in each case one screw which is indicated in fig. 7a, can be released for the purpose of dismantling. Adjusting holes which are also indicated in fig. 7a in the region of the removed nozzles 14 belong with the screws to the installation means, with the aid of which the nozzles 14 can be dismantled and installed.

Although the nozzles 14 can be removed, they of course belong fundamentally to the apparatus 10' ' , in the same way as sensor devices 19'' a to 19' 'd which are shown in fig. 7b.

Said sensor devices 19' ' can be installed in each case with the aid of the same installation means or with the aid of identical installation means on the application head 15 instead of the removed nozzles 14, in particular at the same location.

In other words, the apparatus 10' ' relates to a modular system, in the case of which nozzles 14 can be swapped for sensor devices 19.

Here, the sensor devices 19' ' can function, for example, in exactly the same way as in one of the other exemplary embodiments, that is to say, for example, can be configured in each case as a laser distance sensor or as a laser scanner.

If the sensor devices 19' ' are comparable in each case with one of the laser distance sensors from the first exemplary embodiment, the received profile would then be approximated, for example, not only using two edge profile points, but rather using a plurality of points, namely using four determined profile points in this example. This clarifies a first aspect of the third exemplary embodiment which shows that, instead of merely two or instead of a high number of highly resolved profile points, an in-between number of profile points can be capable of being detected (four in this exemplary embodiment, in particular, for example, between two and twenty profile points) .

A second, fully independent aspect relates to the abovementioned modular character which relates to the described exchangeability of nozzles 14 and sensor device/devices 19' ' . An exchangeability of this type can be provided, in particular, for the case where the respective profile is not measured on-the-fly, but rather, for example, during the fixing of the track, in the case of what is known as a teach-in operation or a track calibration of the apparatus 10' ' (that is to say, without simultaneous dispensing of adhesive) .

A further aspect which is completely independent of the two abovementioned aspects (but which is disclosed or combined together with the two other aspects in the exemplary embodiment according to fig. 7, but is to be considered as disclosed independently thereof) relates to the property of the sensor device/devices 19' ' for the simulation of the adhesive dispensing behavior of the adhesive dispensing apparatus 10' ' with the aid of a light structure which can be projected onto the substrate or workpiece by the sensor device 19' ' .

In other words, the sensor device 19' ' is likewise configured as a projection device. This is appropriate, in particular, for the case where the sensor device 19' ' has an optical (distance) sensor. In this case, said optical sensor can therefore serve not only for the determination of the profile, but rather at the same time can use the light structure which is emitted in any case (for example, in the form of a laser beam) to facilitate what is known as the teach-in operation: in the case of the calibration or configuration or set-up of the corresponding application track/tracks on the substrate or workpiece, the user can detect on the basis of the light structure where adhesive will be applied onto the substrate or workpiece later, in the case of the corresponding track/tracks being moved along (and at the same time can detect/approximate profiles) .

To this end, the light structure is advantageously emitted from approximately the same position as the actual adhesive (later) during the actual application operation. Precisely a configuration of this type is shown in the exemplary embodiment according to fig. 7b.

However, the sensor devices 19 in accordance with the first or the second exemplary embodiment can of course also fundamentally serve as projection device/devices in the above-described sense.

As has already been described, this facilitates a teach- in operation, in the case of which users have in practice up to now held metal pins or the like up to the dispensing nozzle, in order to predict the dispensing behavior of the latter.

The light structure which can be projected can be, for example, laser light, or else any other light which is preferably optically visible and which the sensor device uses for the distance measurement.