TESTING DEVICE AND METHOD FOR TESTING A SURFACE OF A TEST SUBJECT

Description

[0001] The invention relates to a testing device for inspecting the surface of a test specimen. It further relates to a method for inspecting the surface of a test specimen using the testing device.

[0002] Human-caused soft chemomechanical finger or hand abrasion of a surface 202 (see Fig. 1A The action (in which reference numeral 301 denotes a finger acting on the surface 202 in the manner indicated by the arrow) can be simulated and realistically reproduced using testing equipment. Test devices known from the prior art are based on the standard DIN EN ISO 60068-2-70:1996-07. Fig. 1B Figure 1 shows a schematic representation of a test device 101, which, according to the prior art, can be used for abrasion testing of a test specimen 201 having a surface 202 to be tested. The surface 202 of the test specimen 201 to be tested is also referred to below as the test surface 202.

[0003] The abrasion test using the test device 101 is usually performed with the test specimen 201 or its test surface 202 in a vertical position. The test specimen 201 or the test surface 202 is clamped vertically, with the actual loading and abrasion process taking place in a vertical direction against gravity. The test device 101 has a load body 102 which impacts the test specimen 201 or the test surface 202 at an angle of, for example, 45° or 60°, moving in a grinding motion, exclusively against gravity, over a defined path, which may be adjustable and is referred to as the friction path. When the load body 102 is withdrawn from the test specimen 201 or the test surface 202, the load body 102 may partially or completely lift off the surface.

[0004] The load body 102 itself can have different geometries and material properties. For example, in the test devices 101 listed above, the load body 102 is usually a silicone stamp enclosed in a rigid sleeve, such as a metal or plastic part, which is connected to the drive unit 103. A portion of the load body 102 protrudes from the sleeve and has a defined radius of curvature. The drive unit 103 has a rotatably mounted cylinder 108, which has a non-rotating, unidirectionally movable piston 109 (double arrow P1) and is pivotable about an axis P (double arrow P2). The drive unit 103 enables relative movement of the load body 102 (arrows F1 and F2). The radius of curvature in existing testing equipment is usually in the range of 10 to 50 mm, although other radii of curvature are also used.The material of the load body 102 is usually silicone rubber to replicate the elasticity of the human fingertip and human tissue. The test specimen 201 itself can have a wide variety of properties. Smooth or rough, curved or flat, and even movable samples such as electrical switches can be tested. Load bodies 102 exist with different surface roughnesses, surface structures, surface geometries, and surface radii of curvature. The load bodies can be made of different materials.

[0005] The actual contact with the test surface 202 is achieved by a tape, a woven textile, a sponge-like friction medium, or another interwoven structure. The tape, woven textile, sponge-like friction medium, or other interwoven structure is collectively referred to below as the abrasive tape. The abrasive tape 104 hangs vertically between the test surface 202 and the load body 102, with the lower end of the abrasive tape hanging loosely. The front and back sides of the abrasive tape can have different material and / or surface properties. Abrasive tapes are known that are abrasive only on one side or that are impregnated with an active medium or with active particles.

[0006] The abrasive strip 104 serves as an abrasion medium and can be used either dry or impregnated with an active medium 105. The active medium can be applied mechanically or manually, for example, using a pipette or a spatula. It should be noted that a small weight (107) is attached to the lower end of the abrasive strip 104, so that the strip is pulled downwards when no further forces are applied to the load body after the end of its load-bearing capacity. The active medium 105 can be a substance such as artificial sweat, sunscreen, toothpaste, or other substances with which the test surface may come into contact during the intended use of the test specimen 201. The active medium 105 can be supplied to the abrasive strip 104 via a supply line 106. The active medium is sometimes also referred to as the active liquid.

[0007] The test procedure proceeds as follows: The load body 102 moves towards the abrasive strip 104, which hangs loosely in front of the test specimen. It tactilely follows the strip in its direction of movement, strikes the test surface 202 with the abrasive strip 104, and performs the previously described grinding motion against gravity on the test surface 202. After reaching the end of the predetermined friction path, the load body 102 lifts off and detaches from the abrasive strip 104. The abrasive strip 104 is pulled downwards and taut by the weight attached to its lower end, which is referred to as the strip weight.

[0008] After a predetermined number of test load cycles, the abrasive belt 104 is moved downwards by a defined distance, so that the friction contact surface – that is, the section of the abrasive belt that contacts the test surface – once again has a pristine abrasive surface, which now forms the friction contact area. This is necessary because, in a tribological test, both friction surfaces, i.e., the test surface and the friction contact surface, are always worn. The fabric feed for the abrasive belt 104 can be achieved horizontally via a fabric roller or via a 90° deflection, e.g., by a deflection roller, either by a motor or by a sliding mechanism.

[0009] To ensure the reproducibility of a test, it is necessary to make sure that: (i) The abrasive belt feed always occurs in the same number of abrasion cycles. (ii) The abrasive belt 104 does not adhere to the test surface 202. (iii) The coefficient of friction between the load body 102 and the abrasive belt 104 is always greater than the coefficient of friction between the abrasive belt 104 and the test specimen 201, so that the abrasive belt 104 adheres to the load body 102 instead of the test specimen 201.

[0010] If the load-bearing element were to slide or rub against the abrasive belt, the surface roughness, geometry, and the resulting effective contact area would be continuously altered by the abrasive belt and transferred to the test specimen. This would render the load-bearing element unusable and the test would no longer be reproducible.

[0011] Particularly when liquid aqueous, oily, or greasy substances containing solid particles are used as supplementary active media 105, the abrasive strip 104 may adhere more readily to the test surface 202. This process is also unpredictable, necessitating strict and costly monitoring of the entire test, including all its test cycles, to prevent erroneous measurements. It is especially important to ensure that the weight attached to the bottom of the abrasive strip 104 is pulled upwards during the load case – i.e., when the abrasive strip 104 is loaded with the load body 102 – and falls back downwards after traversing the friction path.

[0012] Another problem arises from the limited length of the abrasive belt available for a single test run. After a number n of retraction cycles of the abrasive belt 104, the belt's weight strikes, for example, the surface of the laboratory table on which the entire testing device 101 rests, thus losing its function of keeping the abrasive belt 104 taut. Some users have therefore cut a hole in the laboratory tabletop so that the abrasive belt 104, along with its weight, can move all the way to the floor. However, a disadvantage of this solution is that the downward pulling force, due to the weight of the weight and the abrasive belt's own weight, increases continuously and is therefore not constant. Furthermore, the abrasive belt is stretched in the process, so that the abrasion and load-bearing properties of its surface continuously change. Additionally, the pendulum length of the abrasive belt increases.

[0013] DE 102 05 435 C1 discloses a device for determining the wear resistance of a surface. For this purpose, an abrasive belt is guided from a unwinder to a winder. The abrasive belt is pressed against the surface by a load body during its travel. US 2014 / 0090445 A1 discloses a device for measuring the wear of an object's surface, in which an abrasive belt is guided from a unwinder to a winder. The belt is pressed against the surface by means of a finger probe. The belt moves during the test.

[0014] The object of the invention is to eliminate the disadvantages of the prior art. In particular, a testing device for testing the surface of a test specimen is to be provided, which on the one hand prevents the abrasive belt from adhering to the surface of the test specimen and on the other hand reduces the risk of a change in the weight of the belt.

[0015] This problem is solved by the features of claims 1 and 14. Advantageous embodiments of the inventions result from the features of the dependent claims.

[0016] According to the invention, a test device for testing a surface of a test specimen using an abrasive strip and a load body is provided, wherein the abrasive strip is guided section by section from a supply device, passing through a test area in which the abrasive strip can be brought into contact with the surface of the test specimen under the influence of the load body on the abrasive strip, to a winder, characterized in that the winder has a drive for moving the abrasive strip by means of the winder.

[0017] The test device according to the invention enables the used abrasive belt to be wound up using the winder. This prevents the abrasive belt from adhering to the surface of the test specimen. Furthermore, it reduces the risk of changes in the belt weight and the abrasive belt from oscillating. The winder can ensure that the abrasive belt is tightened on the test specimen, for example, after friction and / or impact stress. The test device according to the invention can include an adjustment device for setting the tightening force exerted by the winder on the abrasive fabric. This adjustment can be made manually or by an electric motor. The adjustment device for setting the tightening force exerted by the winder on the abrasive belt can be a spring-loaded adjustment device or a weight-loaded adjustment device.The spring adjustment device allows the tightening force to be adjusted using a spring. The spring adjustment device can be either manual or electric. The weight adjustment device allows the tightening force to be adjusted using a weight. The weight adjustment device can also be manual or electric. The tightening force can be adjusted depending on the fabric type of the abrasion band and / or the active ingredient used.

[0018] The abrasive strip is fed section by section from the supply unit to the rewinder, passing through a test area where the abrasive strip can be brought into contact with the surface of the test specimen by means of the load body. The abrasive strip only comes into contact with the surface of the test specimen when its transport from the supply unit to the rewinder is interrupted. When the abrasive strip is being transported from the supply unit to the rewinder, it is not in contact with the surface of the test specimen. The abrasive strip is therefore transported discontinuously.

[0019] The abrasive strip can be a previously known abrasive strip. It can serve as an abrasive medium and can be either dry or impregnated with an active agent. The active agent can be applied mechanically or manually, for example, using a pipette or spatula. The abrasive strip can also be used to soil the surface of the test specimen and can therefore also be called a soiling strip. It can also be used to clean the surface of the test specimen and can therefore also be called a cleaning strip.

[0020] The drive mechanism of the test device according to the invention can be a motor for rotating the winder while winding or unwinding the abrasive strip. The motor is hereinafter also referred to as a winding motor. The test device according to the invention can include an unwinder from which the abrasive strip is unwound. The unwinder can have a drive mechanism. The unwinder can thus be actively driven. Alternatively, the unwinder can have a slip clutch. The abrasive strip can be guided from the unwinder to the winder as it passes through the test area. For this purpose, the test device according to the invention can have one or more guide rollers. The abrasive strip can be provided as a coil.

[0021] The test device according to the invention can include a dancer that is movable between an upper and a lower position. The dancer can deflect the abrasion belt to the winder. The dancer can tighten the abrasion belt on the test specimen, for example, after friction and / or impact stress. The dancer can thus replace the weight, either alone or together with the winder. The test device according to the invention can include an adjustment device for setting the tightening force exerted by the dancer on the abrasion fabric. The adjustment device can preset a tightening force intended to hold the dancer in its lower position. The adjustment device for setting the tightening force exerted by the dancer on the abrasion belt can be a spring-loaded adjustment device or a weight-loaded adjustment device.The spring adjustment device allows the tightening force to be adjusted using a spring. The spring adjustment device can be either manual or electric. The weight adjustment device allows the tightening force to be adjusted using a weight. The spring adjustment device can also be manual or electric. The tightening force can be adjusted depending on the fabric type of the abrasion band and / or the active ingredient used.

[0022] The dancer can be a dancer roller. The dancer roller can be rotatably mounted on a dancer roller bracket about a pivot axis (T1). The dancer roller bracket can be rotatably mounted about a pivot axis (T2) that is parallel to and spaced apart from the pivot axis (T1) of the dancer roller. The pivot axis (T1) of the dancer roller can be located in a first vertical plane in its lower position and in a second vertical plane, spaced apart from the first vertical plane, in its upper position. If the dancer roller does not reach the lower position for any reason, the test of the test specimen can be stopped, as otherwise a false test would occur and / or the end of the abrasion belt would be reached.

[0023] The test device according to the invention can include a detection device for recording the dancer's position. The detection device for recording the dancer's position can be, for example, a position measuring system, a position sensor, or a position switch. The position measuring system can, for example, be an optical position measuring system. The dancer's position can be recorded by means of the detection device and transmitted to a control device. In particular, the dancer's position can be recorded electrically. The electrically recorded position can be transmitted as a signal to the control device.

[0024] The control device can be a central control unit for controlling the test apparatus according to the invention. Alternatively, a local control unit can be provided for controlling one or more components, for example, the winder and / or the dancer. A control device can be an electronic data processing device, for example, a computer.

[0025] The testing device according to the invention can include a load body corresponding to load bodies used in previously known testing devices. The load body brings the section of the abrasive strip located within the test area into contact with the surface of the test specimen. Before the load body acts on the abrasive strip, the guide of the abrasive strip from the supply device to the unwinder is interrupted; that is, the section of the abrasive strip located within the test area remains within the test area while the load body acts on the abrasive strip, for example, for a predetermined number of abrasion cycles. This number is understood to be the number of cycles in which the load body is to act on the section of the abrasive strip located within the test area.Only after the specified number of abrasion cycles has been completed is the section of the abrasion belt currently in use within the test area replaced by a new, unused section.

[0026] The test device according to the invention can include a bearing for the load body and a drive unit for moving the load body. The drive unit can have a rotatably mounted cylinder with a non-rotating, unidirectionally movable piston, enabling relative movement of the load body. In a first position, the load body is spaced apart from the abrasive strip, i.e., it does not contact the abrasive strip and does not press the abrasive strip against the surface of the test specimen. In a second position, the load body is in contact with the surface of the abrasive strip facing it, pressing the other surface of the abrasive strip against the surface of the test specimen. The drive element allows the load body to be moved from a first position to the second position and from the second to the first position.While the load body is in the second position, the abrasive strip is not moved by the unwinder. The load body can be positioned in the test device such that it is wholly or partially located within the test area. Preferably, the load body has a contact surface that comes into contact with the surface of the abrasive strip facing it when the load body is moved into its second position. This contact surface can be located within the test area when the load body is in its second position. It can also be provided that this contact surface is located within the test area when the load body is in its first position. The load body is not in contact with the test specimen. It can be provided that, in its second position, the contact surface of the load body faces the surface of the test specimen.It can be aligned parallel to the surface of the test specimen.

[0027] The abrasive strip used can be a known abrasive strip, such as those used in previously known testing devices. Using the testing device according to the invention, the abrasive strip is guided into the testing area such that one of its flat surfaces faces the surface of the test specimen to be tested. In the testing area, the test specimen is preferably arranged such that its surface to be tested is essentially vertical. To hold the test specimen in the testing area, the testing device according to the invention can have a holding device, for example, a holding device in which the test specimen is clamped. The holding device keeps the test specimen immobile. The test specimen is not moved during the test.

[0028] The detection device ensures that the abrasive strip can only be cleaned when it is not in contact with the surface of the test specimen. If the abrasive strip is not in contact with the surface of the test specimen, a gap is formed between the abrasive strip and the surface. The abrasive strip can be cleaned, for example, by blowing it off, preferably by automated blowing.

[0029] The test device according to the invention can have one or more guide rollers for guiding the abrasion strip. It can be provided that one or more guide rollers are arranged between the test area and the winder, i.e., the abrasion strip can be guided to the winder after the test area by means of one or more guide rollers. One or more guide rollers can be arranged between the dancer and the winder, i.e., the abrasion strip can be guided to the winder after the dancer by means of one or more guide rollers. At least one of the guide rollers can be a deflection roller. The test device according to the invention can thus have one or more deflection rollers for guiding the abrasion strip. For example, one or more deflection rollers can be arranged between the dancer and the winder.

[0030] The abrasive strip is fed discontinuously from the supply unit to the winder. The abrasive strip is wound onto the winder section by section. With each section wound onto the winder, a section of the abrasive strip previously located within the test area is replaced by a new section. The length of the wound section is referred to as the shear length. The length of the section exiting the test area is essentially the shear length. Similarly, the length of the section entering the test area is essentially the shear length. The term "essentially" is used to avoid discrepancies between the shear length and the actual length of the section exiting or entering the test area.The section of the abrasive belt that is fed into the test area is characterized by changes resulting, for example, from the tension setting of the abrasive belt or the tensioning force exerted on the abrasive belt by the winder. The section of the abrasive belt that is led out of the test area is hereinafter also referred to as the "used section," and the section of the abrasive belt that is fed into the test area is hereinafter also referred to as the "unused section."

[0031] The testing device according to the invention can include a device for determining the shear length of the abrasive strip. It can be provided that the shear length of the abrasive strip is determined by this device during the retraction process. The term "retraction" here refers to replacing a section of the abrasive strip already used to test the surface of the test specimen with a previously unused section. For this purpose, the used section of the abrasive strip is pulled out of the testing area by the rewinder and replaced by the unused section. The retraction can be combined with a rotation of at least one roller, for example, the guide roller or the dancer roller, the rotation of which is determined by the device for determining the shear length of the abrasive strip.For example, the device for determining the shear length of the abrasive strip can obtain measurement pulses that are forwarded to the central control unit of the test device according to the invention and / or processed in local electronics of the device for determining the shear length of the abrasive strip. The device for determining the shear length of the abrasive strip can also determine the total length of the wound-up abrasive strip. From the total length of the wound-up abrasive strip and the total length of the abrasive strip, the remaining length of the abrasive strip available for testing can be determined. If this length falls below a predetermined value, a warning signal can be issued via a warning device. The warning device can, for example, be a visual and / or audible warning device.The optical warning device can, for example, be a display on which the warning message is shown. The testing device according to the invention can therefore include a display for showing such a warning message.

[0032] It may be provided that one of the guide rollers or the dancer has a device for determining the push length of the abrasive belt. The device for determining the push length of the abrasive belt may, for example, be a position switch or position sensor that determines the position of the guide roller or dancer. In this way, for example, the number of rotations of the guide roller or dancer can be determined. In one embodiment, the device for determining the push length of the abrasive belt is a tachometer disc. The tachometer disc may be attached to the guide roller or the dancer.

[0033] It may be provided that at least one of the guide rollers has guide elements that prevent axial movement of the abrasive belt relative to the axis of rotation of the guide roller. Alternatively or additionally, it may be provided that the dancer roller has guide elements that prevent axial movement of the abrasive belt relative to the axis of rotation of the dancer roller. The guide elements may be circumferential webs extending radially from the surface of the guide roller or dancer roller. These guide elements are also referred to as lateral guide elements because the longitudinal edges of the abrasive belt face the guide elements. The abrasive belt rests against the surface of the guide roller or dancer roller with one of its flat surfaces when it is guided to the winder. The surface is the surface of the shaft of the respective guide roller or the surface of the dancer roller.The longitudinal axis of the shaft is the axis of rotation of the guide roller or the dancer.

[0034] According to the prior art, the abrasive belt was guided only in the area above the test area. This very often resulted in lateral pendulum movements of the abrasive belt, the amplitude of which was also increased by the ballast weight. Lateral pendulum movement of the abrasive belt can be prevented by means of the guide rollers, which are arranged between the test area and the winder, and / or the dancer. For this purpose, it can be advantageous if at least one of the guide rollers and / or the dancer has guiding elements. Preventing lateral pendulum movement allows the use of an abrasive belt with a narrower width compared to the prior art, which results in material and cost savings.

[0035] If the test device according to the invention includes guide rollers with guide elements, the distance between the guide elements of these guide rollers is preferably adjustable. The term "distance" refers to the axis of rotation of the guide roller. If the test device according to the invention includes a dancer with guide elements, the distance between the guide elements of the dancer is preferably adjustable. The term "distance" refers to the axis of rotation of the dancer. The test device according to the invention can be adapted to abrasion strips of different widths by adjusting the distance between the guide elements of a guide roller and / or the dancer.For example, if an abrasion belt of a first width is to be replaced by an abrasion belt of a second width that is larger or smaller than the first width, the distance between the guide elements will be adjusted on all guide rollers that have guide elements and, if present, on the dancer roller if it has guide elements.

[0036] To change the distance between the two guide elements of a guide roller or dancer, at least one of the two guide elements can be adjustably attached to the guide roller or dancer. For example, a guide element or dancer can have a fixing element for releasably fixing the guide element to the guide roller or dancer. After releasing the fixing element, the fixing element can be moved axially, relative to the axis of rotation of the guide roller or dancer, to a predetermined position and fixed in this position by means of the fixing element. The fixing element can, for example, be a screw with which the guide element is fixed to the surface of the guide roller or dancer. Preferably, both guide elements can be adjustable. The surface is the surface of the shaft of the respective guide roller or the surface of the dancer.The guide element can be fixed to the outer shell using the fixing element, for example the screw.

[0037] Alternatively, to change the distance between the two guide elements of a guide roller or dancer, the guide roller or dancer can be provided with a shaft whose length is adjustable. A locking element allows the predetermined length of the shaft to be releasably fixed. An example of a length-adjustable shaft is a telescopic shaft. The two guide elements can be arranged on the ends of the length-adjustable shaft. Changing the length of the length-adjustable shaft is linked to a change in the distance between the two guide elements. In one embodiment, the length-adjustable shaft is a hollow shaft that can be divided in the middle into two tube halves, whereby the two tube halves can be slid into one another and locked in any desired position.

[0038] The rewinder can be a winding roller. The winding roller can also be called a receiving roller. If the rewinder is a winding roller, the winding roller can have guide elements that prevent axial movement of the abrasive belt relative to the winding roller's axis of rotation. These guide elements can be circumferential webs extending radially from the outer surface of the winding roller. The outer surface is the surface of the winding roller's shaft. The longitudinal axis of the shaft is the winding roller's axis of rotation. Preferably, the distance between the guide elements of the winding roller is adjustable. For this purpose, the guide elements can be adjustable, as already described in connection with guide rollers, or the winding roller's shaft can be extendable, also as already described in connection with guide rollers.

[0039] If the test device according to the invention includes an unwinder, the unwinder can be an unwind roller. The unwind roller can also be referred to as a guide roller. If the unwinder is an unwind roller, the unwind roller can have guide elements that prevent movement of the abrasion belt in the axial direction, relative to the axis of rotation of the unwind roller. The guide elements can be circumferential webs that extend radially from the surface of the unwind roller. The surface is the surface of the shaft of the unwind roller. The longitudinal axis of the shaft is the axis of rotation of the unwind roller. Preferably, the distance between the guide elements of the unwind roller is adjustable. For this purpose, the guide elements can be adjustable, as already described in connection with guide rollers, or the shaft of the unwind roller can be extendable, as also already described in connection with guide rollers.

[0040] If the testing device according to the invention has a trough feed instead of an unwinder, the trough can be adjusted to the width of the abrasion belt. For example, the trough width can be adjustable. Alternatively or additionally, one or more spacer elements, also referred to as spacing elements, can be provided. The spacer element(s) can be inserted into the trough in such a way that they abut an inner wall of the trough, thereby reducing the width of the interior of the trough. By removing one or more spacer elements from the trough, the width of the interior can be increased again. The side wall(s) of the support against which the spacer elements abut can be the side walls facing a longitudinal edge of the abrasion belt. By means of the spacer element(s), the trough width can thus be adjusted laterally to the required width.

[0041] To enable the retrofitting of existing test equipment, the winding mechanism for the used abrasive fabric can be provided as a module. This module can be installed on an existing test equipment. The module includes the winder. It can also include one or more guide rollers and / or the dancer element. Furthermore, it can include a device for determining the shear length of the abrasive belt. Providing the winding mechanism for the used abrasive fabric as a module allows for the integration of existing test equipment that uses a roller or trough feed for the abrasive belt, thus supplementing known guide systems for the abrasive belt. The abrasive belt winding mechanism can be integrated either directly into the central control unit of the test equipment or via a local control unit. The module can have a frame to which the winder and, if present, the other elements of the module are attached.In one embodiment of the invention, the module includes both the winder and the unwinder. The module can thus also be configured as an unwinding and winding unit. The unwinding and winding unit can include one or more guide rollers and / or the dancer. It can also include a device for determining the push length of the abrasive belt.

[0042] Apart from the guiding of the abrasion belt by means of the winder and, if provided, one or more guide rollers and / or the dancer, the test device according to the invention can correspond to test devices known from the prior art. In particular, the test device according to the invention can have one or more components that are part of the test devices known from the prior art. However, the test device according to the invention does not have a weight at the end of the abrasion belt. The test device according to the invention can, for example, have a drive unit for moving the load body, which corresponds to the drive unit known from the prior art. It can also have another drive unit for moving the load body that is known per se from the prior art. Furthermore, it can have a supply line for an active medium, which corresponds to the supply line known from the prior art.

[0043] A counter roller can be used to determine the length of the abrasive belt that has been wound onto the winder. The counter roller can be the dancer. Alternatively or additionally, at least one of the guide rollers can be a counter roller.

[0044] According to the invention, a method for testing the surface of a test object using the test device according to the invention is provided, wherein an abrasive strip is guided section by section from a supply device, passing through a test area in which the abrasive strip is brought into contact with the surface of the test object under the influence of a load body, to a winder, wherein the abrasive strip is movable by means of a drive that drives the winder.

[0045] It may be provided that the tension of the abrasive strip is changed by rotating the winder. By rotating the winder in one direction, the abrasive strip can be wound onto it. Winding the abrasive strip allows the section of the strip that is in the test area and has usually already been used for testing to be removed and replaced with a new, unused section. However, the tension of the abrasive strip can also be adjusted by rotating the winder in the first direction or in the opposite direction.

[0046] The supply unit can be, for example, the unwinder or, in the case of a trough feed, a trough.

[0047] The inventive method and device enable the guiding of an abrasive belt, with adjustable tension, from the supply unit to the unwinder. This eliminates the need for a weight attached to the end of the abrasive belt. Further details of the inventive method have already been described in connection with the inventive device. Reference is made to these details.

[0048] The inventive method and apparatus ensure reproducibility in the surface testing of a test specimen. In particular, it ensures that the abrasive belt feed always occurs in the same number of abrasion cycles and that the abrasive belt does not adhere to or stick to the surface of the test specimen. This can be achieved by changing the tension of the abrasive belt in the test area to create a gap between the abrasive belt and the surface of the test specimen.

[0049] After the surface of the test specimen has been brought into contact with the abrasion belt for the specified number of abrasion cycles, the surface of the test specimen can be assessed using methods known per se. For example, the roughness of the surface can be assessed, e.g., using a roughness measuring probe or by optical methods.

[0050] The invention is explained in more detail below with reference to exemplary embodiments, which are not intended to limit the invention, and with reference to the drawings. Fig. 1A A schematic representation of a surface to be touched by a finger; Fig. 1A Schematic representation of an exemplary testing device according to the prior art; Fig. 2A A schematic representation of a first embodiment of a testing device according to the invention; Fig. 2B Schematic representation of a movement sequence of a load body during testing; Fig. 3 A schematic representation of a second embodiment of a testing device according to the invention; Fig. 4 A schematic representation of a third embodiment of a testing device according to the invention; Fig. 5A A top view of a roller; Fig. 5B Sectional view of the Fig. 5A shown roll, cut along cutting line A--A of Fig. 5A ; and Fig. 6 a perspective view of a module for winding the abrasion belt.

[0051] The in Fig. 2A The first embodiment of a test device 1 according to the invention, as shown, has a disentanglement roller 2 and a winding roller 3. An abrasion strip 4 is unwound from the disentanglement roller 2 and guided through the test area 5 to the winding roller 3, onto which the abrasion strip 4 is wound. In the test area 5, the test specimen 201 is arranged such that its surface 202 to be tested is in a vertical position. The section of the abrasion strip 4 located in the test area 5 is oriented such that—as long as the load body 6 does not act on the abrasion strip 4—the flat surfaces of the abrasion strip 4 run parallel to the surface 202 of the test specimen 201 in vertical planes and are spaced apart from it by a gap 7.

[0052] The unwinding roller 2 has a rotational axis D. The winding roller 3 has a rotational axis E. The rotational axes D and E are horizontal and parallel to each other. The rotational axis E is spaced apart from the rotational axis D and is located lower than the rotational axis D. The unwinding roller 2 and the winding roller 3 can each be rotatably mounted on a common frame. The unwinding roller 2 and the winding roller 3 can be arranged such that the abrasion strip 4 is in a vertical position in the test area 5.

[0053] The abrasive strip 4 is unwound section by section from the unwinding roller 2 for testing the surface 202 of the test specimen 201 (arrow A). The winding roller 3 is equipped with a motor (not shown) for this purpose. By rotating the winding roller 3 in a first direction (arrow B), the abrasive strip 4 is wound onto the winding roller 3 section by section. The section of the abrasive strip 4 located in the test area 5, preferably after its use in testing the surface 202, is then moved out of the test area 5. Simultaneously, a new, unused section of the abrasive strip 4 enters the test area 5. As soon as the new, unused section of the abrasive strip 4 has entered the test area 5, the winding of the abrasive strip onto the winding roller 3 is stopped. If necessary, however, the tension of the abrasive strip can be adjusted.To do this, the winding roller 3 is rotated around its axis of rotation (E) in the first direction (arrow B) or in the opposite direction (arrow C) until the abrasive belt 4 has the specified tension. To adjust the tension, the winding roller 3 can be rotated several times in the first direction or in the second direction, or alternately in one direction and then the other.

[0054] If the new, unused section of the abrasive strip 4 is located in the test area 5 and the abrasive strip 4 exhibits the specified tension, the testing of the surface 202 of the test specimen 201 can begin. It may be stipulated that the abrasive strip 4 is not moved by the winding roller 3 during the test.

[0055] The test can be carried out in a manner known from the prior art. For this purpose, the load body 6 acts on the flat side of the abrasive strip 4 that faces away from the surface 202 of the test specimen 201. The load body 6 can be moved by means of the drive unit 8 such that it is moved at an angle α towards the surface 202, thereby pressing the abrasive strip 4 against the surface 202. The drive unit 8 has a rotatably mounted cylinder 21, which has a non-rotating, unidirectionally movable piston 22 (double arrow P1) and is pivotable about a horizontal axis P (double arrow P2). The drive unit enables a relative movement of the load body 6 (arrows F1 and F2). The load body 6 can perform a grinding motion, exclusively against the force of gravity. It can be moved along a defined path, which may be adjustable and is called the friction path.The load body 6 can then be moved away from the abrasion belt 4, thereby detaching the abrasion belt 4 from the surface 202. An example of the movement of the load body 6 is shown in Figure 1. Fig. 2B The trajectory is shown. The described forward movement of the load body towards the surface 202 at angle α, the grinding movement of the load body while pressing the abrasive strip 4 against the surface 202, and the subsequent return movement of the load body, which releases the abrasive strip 4 from the surface 202, can form a cycle. This cycle can be repeated multiple times. The angle α can be, for example, 45° or 60°.

[0056] The surface 202 is subjected to a predetermined number of cycles. During this process, the section of the abrasive strip 4 located in test area 5 is not changed. After the predetermined number of cycles has been completed, the currently used section of the abrasive strip 4 is replaced by a new, unused section by winding a section of the abrasive strip onto the winder 3. This wound section has a predetermined length, referred to as the shear length. The shear length corresponds to the length of the abrasive strip 4 that must be wound up so that the new, unused section reaches test area 5 and occupies it in such a way that the surface 202 can now be tested with this new, unused section. A position sensor (not shown) can be provided to determine the shear length by determining the position of the winder.In this way, position data can be obtained and transmitted to a central or local control unit (not shown). The control unit can cause the winding roller 3 (arrow B) to rotate via the motor. To adjust the tension of the abrasive belt 4, the control unit can also cause the winding roller 3 to rotate in the direction of arrow B or C.

[0057] The abrasive strip 4 can be used either dry or impregnated with an active medium 24. The active medium 24 can be applied mechanically or manually, for example, using a pipette or a spatula. The active medium 24 can be a substance such as artificial sweat, sunscreen, toothpaste, or other substances with which the test surface may come into contact during the intended use of the test specimen 201. The active medium 24 can be supplied to the abrasive strip 4 via a supply line 23.

[0058] The in Fig. 3 The second embodiment of a test device 1 according to the invention shown corresponds to the one shown in Fig. 2A The first embodiment shown differs from the first, except that two additional guide rollers 9, 10 are provided for guiding the abrasion strip 4. The two guide rollers 9, 10 serve to guide the abrasion strip 4 exiting the test area 5 to the winding roller 3. The two guide rollers have horizontal axes of rotation that run parallel to the axes of rotation D, E of the unwinding roller 2 and the winding roller 3. The two guide rollers 9, 10 can also be rotatably mounted about their axes of rotation on the frame on which the unwinding roller 2 and the winding roller 3 are already rotatably mounted.

[0059] The first guide roller 9 is a deflection roller and is arranged such that the abrasion belt 4 is guided vertically through the test area 5. This can be achieved by a corresponding arrangement of the guide roller 9 relative to the unwind roller 2. In contrast to the first embodiment, the vertical position of the abrasion belt 4 in the test area 5 is not achieved by aligning the winding roller 3 with the unwind roller 2. The first guide roller 9 is located in the Fig. 3 In the third embodiment shown, the winding roller 3 is arranged lower.

[0060] The abrasive strip 4 passes from the unwind roller 2 through the test section 5 to the first guide roller 9. From the first guide roller 9, the abrasive strip 4 is guided to the second guide roller 10, whose axis of rotation lies in the same horizontal plane as the axis of rotation of the first guide roller 9. The second guide roller 10 serves as a counter roller. It can be used to determine the feed length of the abrasive strip. The length of the abrasive strip wound onto the rewinder can be determined using the counter roller. The length determined by the counter roller can be transmitted to a central or local control unit (not shown). The control unit can cause the rewind roller 3 (arrow B) to rotate via the motor. To adjust the tension of the abrasive strip 4, the control unit can also cause the rewind roller 3 to rotate in the direction of arrow B or C.The abrasion belt 4 lies with its flat side, which faces the surface 202 of the test specimen 201, against both the first guide roller 9 and the second guide roller 10.

[0061] The in Fig. 4 The third embodiment of a test device 1 according to the invention shown corresponds to the one shown in Fig. 3 The second embodiment shown differs, except that a dancer roller 11 is additionally provided for guiding the abrasive belt 4, and the abrasive belt 4 is guided through a gap formed between the two guide rollers 9 and 10. The dancer roller 11 is rotatably mounted on a dancer roller bracket 12. The dancer roller bracket 12 is rotatably mounted about an axis of rotation (T 2) that is parallel to and spaced apart from the axis of rotation (T 1) of the dancer roller. For this purpose, the dancer roller bracket 12 can be rotatably attached to the common frame. The axis of rotation (T 1) and the axis of rotation (T 2) are horizontal and run parallel to the axes of rotation of the unwinder 2, the guide rollers 9 and 10, and the rewinder 3.

[0062] The dancer roller 11 is arranged such that the abrasion belt 4 is guided vertically through the test area 5 when the dancer roller 11 is in its lower position. This can be achieved by a corresponding arrangement of the dancer roller 11 relative to the unwinding roller 2. In contrast to the second embodiment, the vertical position of the abrasion belt 4 in the test area 5 is not achieved by the alignment of the first guide roller 9. In the Fig. 4 In the embodiment shown, the dancer roller 11 is arranged above the first guide roller 9.

[0063] The abrasion strip 4 passes from the unwinding roller 2 through the test area 5 to the dancer roller 11 and from there to the first guide roller 9, passes the second guide roller 10, which serves as a counting roller, and from which it is guided to the winder 3. The abrasion strip 4 rests with its flat side facing away from the surface 202 of the test specimen 201 against the first guide roller 9 and with its flat side facing the surface 202 of the test specimen 201 against the second guide roller 10.

[0064] The dancer's roll 11 can be moved between a lower position and an upper position. The upper position is in Fig. 4 The diagram is shown by dashed lines. To move the dancer roller 11 from the lower to the upper position or vice versa, the dancer roller 11 is pivoted about its axis of rotation T2 by means of the dancer roller bracket 12. In the lower position, the axis of rotation T1 of the dancer roller 11 lies in a first horizontal plane and a first vertical plane. In the upper position, the axis of rotation T1 of the dancer roller 11 lies in a second horizontal plane, which is spaced apart from and above the first horizontal plane, and in a second vertical plane, which is spaced apart from the first vertical plane. The distance between the axis of rotation T1 of the dancer roller 11 and the axis of rotation T2 of the dancer roller bracket 12 remains unchanged during the pivoting motion.

[0065] The test device 1 may include an adjustment device (not shown) for adjusting the tensioning force exerted by the dancer 11 on the abrasive belt 4. The adjustment device presets a tensioning force intended to hold the dancer in its lowered position. This tensioning force is applied to the dancer roller holder 12 by means of the adjustment device.

[0066] The test device according to the invention includes a detection device (not shown) for detecting the position of the dancer roller 11. If the detection device determines that the dancer roller 11 has not reached the lower position for any reason, the inspection of the surface 202 of the test specimen 01 can be stopped, as otherwise a false test would occur and / or no further abrasive strip 4 could be unwound from the unwinding roller 2, thus reaching the end of the abrasive strip 4. The detection device is a position sensor that detects the position of the dancer roller 11 and transmits it to a control device.

[0067] In the Figuren 5A und 5B A roller 13 is shown, which can be a guide roller, an unwind roller, a winding roller, or a dancer roller. The roller 13 has a shaft 14 with a rotation axis Y and a surface 15. The roller 13 also has two guide elements 20, which are spaced apart from each other by a distance z relative to the rotation axis Y. The distance z is adapted to the width of the abrasive belt 4, so that axial movement of the abrasive belt relative to the rotation axis Y of the shaft is prevented. The distance z between the two guide elements 20 can be varied, for example, by moving one or both guide elements 20 on the shaft 14 or by changing the length of the shaft 14.

[0068] Fig. 6 Figure 16 shows a module in which the winder 3, the first guide roller 9, and the second guide roller are attached to a frame 17. The winder 3, the first guide roller 9, and the second guide roller correspond to the one shown in Figure 16. Fig. 3 The second embodiment of the test device 1 shown is required for winding up the abrasion belt 4 after it leaves the test area 5. Module 16 can further comprise the motor for rotating the winding roller 3 and at least one device for measuring the push length of the abrasion belt 4, which are arranged in a housing 19 attached to the frame 17. The housing 19 is also a component of module 16.

[0069] Module 16 can be used to retrofit existing test equipment. For power supply and data exchange between electronic components of Module 16 and a control unit, Module 16 has a connection 18. Reference symbol list

[0070] 1 Test device 2 Unwind roller 3 Rewind roller 4 Abrasion belt 5 Test area 6 Load body 7 Gap 8 Drive unit 9 First guide roller 10 Second guide roller 11 Dancer 12 Dancer roller bracket 13 Roller 14 Shaft 15 Sheath 16 Module 17 Frame 18 Connection 19 Housing 20 Guide element 21 Cylinder 22 Piston 23 Supply line 24 Working medium 101 Testing device 102 Load body 103 Drive unit 104 Abrasion belt 105 Active medium 106 Supply line 107 Weight 201Test subject 202Test surface 301Finger

Claims

1. A testing device (1) for testing a surface (202) of a specimen (201) using an abrasion ribbon (4) and a load body (6), wherein the testing device has the abrasion ribbon (4), the load body (6), a provision apparatus (2), a testing area (5), a winder (3), and a control apparatus for controlling the testing device (1), characterized in that the abrasion ribbon (4) is guided in sections from the provision apparatus (2) through the testing area (5), where the abrasion ribbon (4) can be brought into contact with the surface (202) of the specimen (201) under the action of the load body (6) on the abrasion ribbon (4), to the winder (3), wherein the winder (3) has a drive for moving the abrasion ribbon (4) by means of the winder (3) and the control apparatus causes rotation of the winder (3) via the drive, wherein the abrasion ribbon (4) is only brought into contact with the surface (202) of the specimen (201) when the transportation of the abrasion ribbon (4) from the provision apparatus (2) to the winder (3) is interrupted, and wherein the abrasion ribbon (4) is not in contact with the surface (202) of the specimen (201) when the abrasion ribbon (4) is transported from the provision apparatus (2) to the winder (3).

2. The testing device according to claim 1, characterized in that the drive is a winding motor for rotating the winder (3) to wind or unwind the abrasion ribbon (4).

3. The testing device according to any of the preceding claims, characterized in that it is an apparatus for determining the feed length of the abrasion ribbon (4).

4. The testing device according to any of the preceding claims, characterized in that it further has one or more guide rolls (9, 10) that are arranged between the testing area (5) and the winder (3).

5. The testing device according to any of the preceding claims, characterized in that it further has a dancing bar (11) which can be moved between an upper position and a lower position.

6. The testing device according to claim 5, characterized in that it has an adjusting apparatus for adjusting the tensioning force exerted by the dancing bar (11) on the abrasion ribbon, wherein a tensioning force is pre-set by means of the adjusting apparatus that is to hold the dancing bar (11) in its lower position.

7. The testing device according to claim 5 or claim 6, characterized in that it has a detecting apparatus for detecting the position of the dancing bar (11).

8. The testing device according to claim 7, characterized in that the detecting apparatus is a sensor or a switch.

9. The testing device according to any of claims 5 to 8, characterized in that the dancing bar (11) is a dancing bar roll that is rotatably mounted about a rotational axis (T1) on a dancing bar roll holder (12).

10. The testing device according to claim 9, characterized in that the dancing bar roll holder is rotatably mounted about a rotational axis (T2) that is in parallel to the rotational axis (T1) of the dancing bar roll (11) and spaced apart from it.

11. A testing device according to any of claims 5 to 10, characterized in that the dancing bar (11) in its lower position is located in a first vertical plane and in its upper position in a second vertical plane that is spaced apart from the first vertical plane.

12. The testing device according to any of claims 5 to 11, characterized in that the dancing bar (11) is a counting roll (10), or according to claim 4, characterized in that at least one of the guide rolls (9, 10) is a counting roll.

13. The testing device according to any of claims 5 to 12, characterized in that the dancing bar (11) has lateral guiding elements (20) which prevent movement of the abrasion ribbon (4) in an axial direction with respect to the rotational axis of the dancing bar (11).

14. A method for testing a surface (202) of a specimen (201) using a testing device (1) according to any of claims 1 to 13, characterized in that an abrasion ribbon (4) is guided in sections from the provision apparatus (2) through the testing area (5), where the abrasion ribbon (4) is brought into contact with the surface (202) of the specimen (201) under the action of the load body (6) on the abrasion ribbon (4), to a winder (3), wherein the abrasion ribbon (4) can be moved by means of a drive driving the winder (3).

15. The method according to claim 14, characterized in that the tension of the abrasion ribbon (4) is changed by rotating the winder (3).