Device for testing conductors

Abstract

Device (2) for testing conductors, comprising - a force transmission device (6) with a contact element (8) to be applied to a ladder (4) to be tested for transmitting a force directed in a test force direction (PR) to the ladder (4) and - a force sensor to determine the force, - a movable actuator (10) comprised by the force transmission device (6) and coupled to the contact element (8) for generating the force and - a control device comprising the force sensor and connected to the actuator (10), which is configured to control the actuator (10) in such a way that a defined test force can be automatically transmitted to the conductors (4) by means of the contact element (8), characterized in that the device frame (26) and rollers (32) mounted on the device frame (26) for moving the device (2) and the device (2) can be used in a mobile manner.

Description

The invention relates to a device for testing conductors. The device has a force transmission device which comprises an abutment element. The contact element is to be placed on a conductor to be tested. The contact element serves for transmitting a force directed in a test force direction to the conductors. In addition, the device has a force sensor for determining the force.A function and load test is to be carried out on conductors before their first intended use. This must also be repeated at least every 24 months. The basis of the test is in particular the standards DIN 14710 et seq., according to which the conductors are to be loaded, inter alia, with specific forces in specific directions and, for example, a load-dependent deflection is to be measured.From this a device for testing conductors is known, which has a cable winch connected to the contact element via a deflected cable, by means of which a tester must generate the force to be transmitted. The entire testing of a ladder with this device is complicated and subject to significant uncertainties. After each introduction of force, the tester has to check the force sensor spaced from the cable winch until the desired test force is transmitted. He then has to manually remeter the deflection produced thereby, for example using a limb scale. With the cable, the force transmission device has an element which yields permanently under tension and makes it difficult to maintain the test force. On the basis of the above points, with the known device, it is possible to determine test results only with a high expenditure on time and physical effort, which test results are subject to comparatively great uncertainties and are not reproducible without significant deviations.KR 10 1 942 936 B1 discloses a conductor test stand which has two support elements arranged on a base plate. Between the support elements, a measuring unit for measuring the deformation of a conductor to be tested is arranged. A conductor to be tested is placed on the support members so as to extend over the measurement unit. A force is applied to the conductors to be tested via a pressure die opposite the measuring unit. The applied force and the measured deformation can be recorded.The one apparatus for testing vertically oriented conductors.Furthermore, DE 10 2018 000 751 B3 and the further devices are known for carrying out bending tests in particular, which however do not serve specifically for testing conductors.The object of the invention is to improve the previously known devices in such a way that the test can be carried out with less effort.According to the invention, the device has an actuator, which is included by the force transmission device, for generating the force. The actuator is configured to be movable and coupled to the bearing element. The actuator can be operated hydraulically, pneumatically or electrically. Furthermore, the device has a control device comprising the force sensor and connected to the actuator. The control device is configured to actuate the actuator in such a way that a defined test force can be automatically transmitted to the conductors by means of the contact element.The device according to the invention is in particular a test bench. The device can be used in a mobile manner. The device has a device frame, in particular made of aluminum profiles, and rollers mounted on the device frame for moving the device. The bearing element is arranged in particular at a height of approximately 80 cm. The device is preferably designed such that the contact element protrudes above the device frame into a conductor receiving space in which a section of the conductors to be tested, which extends in particular on both sides over the device frame, is arranged for testing. For positioning the conductors to be tested, the device preferably has at least one stand element which is preferably movable relative to the device frame and in particular is to be stowed thereon. The device preferably has a cover, in particular a hinged cover, by means of which the contact element or a section of the conductors to be tested, on which the contact element acts, is to be covered during the test. The cover is preferably at least partially formed from a transparent material, in particular Plexiglass.Ladders are understood to be devices with rungs which allow ascending and descending. In particular, conductors are formed from lateral and parallel extending beams, between which the shoots extend. Conductors are usually formed from wood or from metal. Exemplary ladders are the hook, plug, folding and sliding ladders, which partially comprise a plurality of ladder elements movable relative to each other, which in particular already form a ladder independently. The contact element is designed for its arrangement on the conductor to be tested, in particular on a muntin thereof, in order to transmit the force directed in the test force direction to the conductors to be tested.The force sensor is arranged in particular on the force transmission device or a part thereof. The force sensor is preferably arranged between the actuator and the device frame or between the bearing element and the actuator. The force sensor measures either directly the force transmitted to the conductors or a force which, in particular on the basis of a known transmission ratio, indicates the force transmitted to the conductors or permits the calculation of the force transmitted to the conductors. The force transmission device is in particular a mechanical string of components which ends in the bearing element starting from the device frame. The force sensor, which may be spaced apart spatially from further components of the control device, generates a signal corresponding to the measured force for processing by the control device.The control device preferably comprises at least one processor for processing the signal of the force sensor. In particular, the control device comprises a programmable logic controller (PLC). The control device controls the actuator by a further signal which is dependent on the signal of the force sensor.The actuator is preferably an actuator, in particular an actuating cylinder. The actuator is movable in so far as at least a part of it is movable relative to the device frame and, if applicable, to any further part of the actuator. The actuator is designed to generate the force in that it produces or converts kinetic energy from a different energy form. The force generated by the actuator during operation either directly corresponds to the force transmitted to the conductors or causes the force transmitted to the conductors via a transmission.The control device preferably forms a control circuit for transmitting the test force. On the basis of the monitoring provided by the force sensor and the automatic actuation of the actuator dependent thereon, the test force can be set with the highest precision. In particular, the test force can be maintained for specific periods of time without the need for a separate exertion of force by the tester. The device according to the invention thus permits simpler and more precise force transmission to conductors and thus its simpler and more precise testing.The control device preferably has a travel sensor device. The travel sensor device serves to determine a travel covered by at least a part of the force transmission device in a travel measurement direction. The distance measuring direction is in particular equal to the test force direction. Alternatively or additionally, the travel sensor device serves to determine a travel covered by at least a part of the conductors to be tested in the travel measurement direction. The travel sensor device comprises, in particular, a travel sensor, preferably a position transmitter, or is formed thereby. The travel sensor device is in particular a separate unit, which is arranged on the force transmission device, or is comprised by the force transmission device, in particular the actuator. The same applies to the force sensor. The part of the force transmission device is preferably the contact element or the actuator. In addition to a precise setting of the test force, the travel sensor device also enables a precise determination of the travel distance covered without the tester having to use inaccurate measurement methods for this purpose. In particular, it is possible by the control device, in the presence of the travel sensor device, to automatically determine the distance travelled after the defined test force is applied, in particular for a specific period of time.The control device is preferably designed for automatic execution of a test sequence. The test sequence comprises that in a first step, the actuator is moved from an initial position, in which it transmits no force or only a force to be ignored to the conductors, until the contact element transmits a zero-position force to the conductors that is less than the test force in a first direction, which corresponds in particular to the test force direction. The test force is in particular many times greater than the zero position force, which serves only to establish contact between the contact element and the conductors and / or to fully extend the force transmission device apart from the actuator. In a second step, the travel sensor device determines a zero position of the part of the force transmission device, in particular while the contact element transmits the zero position force. In a third step, the actuator is moved in the first direction until the contact element transmits the defined test force to the conductors. In a fourth step, the travel sensor device determines a test position of the part of the force transmission device, in particular while the contact element transmits the test force. The travel sensor device preferably then determines the travel of the part covered for transmitting the test force on the basis of the zero position and the test position. The test sequence is in particular a test sequence which runs automatically after triggering by the tester. This further reduces the effort for the tester and increases the accuracy of the determination of the deflection or of the distance covered.The apparatus preferably has a storage unit comprised by the control device. The control device is configured such that the distance travelled is stored in the storage unit. This is a short-term storage (for example for the purposes of subsequent output) and / or long-term storage. With the distance travelled, in particular the defined test force, the test time and / or further data relevant for the test are stored. This results in easier use of the test results.The control device preferably comprises an output device. Furthermore, the control device is preferably configured such that different information is output by the output device depending on the distance travelled. The information output also depends in particular on a distance covered during a preceding test, for example in the front. The output device comprises in particular a display, preferably a touch screen display, and / or lamps. The information preferably relates at least to, among other things, the distance travelled and preferably to a signal for assessing whether or not the conductor under test passed the test.The control unit advantageously comprises an operator input device. Furthermore, the control device is preferably configured such that the actuation of the actuator by means of the operator input device is to be triggered by a user such as the tester. Furthermore, in particular, the test force by the operator is to be defined by means of the operator input device. In particular, the test procedure is to be triggered by the operator input device. Furthermore, different test sequences, for example for different conductor types, test forces and / or test force directions, are preferably to be selected by the operator input device.The operator input device is preferably formed by a mobile device relative to the force transmission device or the device frame. Particularly preferably, the operator input device is a portable terminal, tablet or smartphone. The operator input device is preferably connected wirelessly or by cable to the further parts of the control device. The mobile design increases the safety of the tester in that he can maintain a safety distance from the force transmission device to the conductor when the test sequence is triggered. In this case, in particular no cover is necessary. If, on the other hand, the operator input device is arranged stationary with respect to the device frame, the operator input device is preferably arranged on a side of the device frame on which hinges of the cover, by means of which it is pivotable about a horizontal axis, are arranged.The actuator is preferably formed by a hydraulically, pneumatically or electrically operable adjusting cylinder. In the case of the design as a hydraulic actuating cylinder, the device preferably has its own closed oil circuit with an oil pump to be driven electrically. Both in the case of the hydraulically operable control cylinder and in the case of the electrically operable control cylinder, the device preferably has a plug for connecting the device to the power supply system. In the case of the pneumatically operable adjusting cylinder, the device preferably has a compressed air hose for coupling to a local compressed air network. The prescribed designs of the actuator allow precise adjustment of the test force and the applicability of the device in different environments.The actuator is preferably designed such that it is translationally movable in a direction of travel. The direction of travel is in particular the same as the direction of testing force and / or the distance measuring direction. Instead of the preferred adjusting cylinder, the actuator can also be designed, for example, as a motor, preferably as a hydraulic motor. The translatory movement simplifies the mechanical system for transmitting force from the actuator to the conductors, in particular in the case where the directions mentioned are the same.The actuator is preferably designed such that it is movable at most over at least 75 mm, in particular over at least 200 mm. This means that the maximum travel path of the actuator in the travel direction has at least the indicated length. This ensures that even in the case of a direct coupling of the bearing element and the actuator, a critical deflection of the conductors, which according to DIN standard is 65 mm or 75 mm depending on the conductor material, can be established.The actuator is preferably designed to generate a force of at least 500 N and / or at most 3,000 N. In particular, the actuator is designed to generate a force of at least substantially 784.8 N and / or 2.452.5 N. "Substantially" means that the values are to be achieved irrespective of measurement inaccuracies, rounding errors and the like. As a result of this configuration of the actuator, the test forces required for the conductor test according to DIN standard can be transmitted to the conductors even if no transmission ratio is present between the bearing element and the actuator, which is advantageous for simplifying the device.Preferably, the actuator is arranged at least substantially between the contact element and a contact surface of the device. The footprint is an imaginary plane, which is adjoined by the device with feet or rollers to be placed on the ground during operation. The support surface preferably extends horizontally. The actuator is particularly preferably arranged in such a way that the direction of travel is oriented at right angles to the footprint. This means in particular that the actuator is mounted upright in the device frame. Thus, the force generated by the actuator can be used directly as a test force, wherein the conductors can be arranged conveniently horizontally depending on the test type.The bearing element is preferably arranged on a further part of the force transmission device by means of a coupling device. The coupling device is preferably designed such that the bearing element can be pivoted, for the further part, at least in an inoperative state, about a pivot axis, in particular parallel to the contact surface. The further part of the force transmission device is preferably the aforementioned part of the force transmission device, in particular the actuator. The pivotability of the contact element facilitates its arrangement on the conductor to be tested. In particular, the conductors to be tested can be placed above the device and the contact element can then be folded from the side over a step to be loaded.The coupling device preferably has a first coupling partner and a second coupling partner. The bearing element and the further part form one of the two coupling partners. The first coupling partner forms an elongated hole which is continuous in the direction of the pivot axis and extends longitudinally in an elongated hole direction extending transversely thereto. The second coupling partner extends through the elongated hole. The second coupling partner is pivotable relative to the first coupling partner and is displaceable relative thereto in the elongated hole direction. In detail, the bearing element preferably forms the first coupling partner and the further part forms the second coupling partner or the bearing element forms the second coupling partner and the further part forms the first coupling partner. Due to the above-described construction of the coupling partners, it is also possible without a movement of the actuator to lower the contact element thereon after pivoting via the muntin bar and thus fix it thereto, so that the subsequent force transmission is ensured.Preferably, the contact element forms a muntin receptacle space which is at least partially L- or U-shaped in a longitudinal section. This is to be understood such that the L- or U-shape corresponds at least substantially to the contour of the muntin accommodating space in longitudinal section. This makes it possible for one lateral or two lateral legs of the contact element to contact one or more sides of the rung during lowering and to prevent the contact element from slipping relative to the conductor to be tested. In particular, when the contact element is arranged on the ladder for testing, the muntin receiving space is open downward or towards the pivot axis and / or the muntin receiving space is formed in such a way that a muntin of the ladder is to be introduced into the muntin receiving space from the direction of the pivot axis. This means that the last part of the movement of the rung into the receiving space relative to the abutment element takes place away from the pivot axis without the entire movement having to take place exclusively in this direction.The control device preferably comprises at least one safety sensor. In this case, the control device is preferably designed in such a way that when the safety sensor is triggered, the automatic transmission of the test force is prevented, in particular even when the actuation of the actuator by a user is triggered simultaneously. The safety sensor is preferably a two-hand sensor which triggers as long as the user has not arranged both hands on a respective sensor part of the two-hand sensor. Alternatively or additionally, the safety sensor is a sensor which triggers if the cover is not closed. Alternatively or additionally, the safety sensor is an emergency stop switch, which triggers upon its actuation. This significantly increases the safety for the operator.The device preferably has at least one ballast space for receiving at least one ballast unit. In this case, the at least one safety sensor is preferably arranged on the ballast space in such a way that the safety sensor triggers in the event of a lack of ballast unit in the ballast space. The device preferably has a plurality of ballast spaces, in particular eight ballast spaces, to each of which a safety sensor is preferably assigned. A ballast unit is to be introduced into each ballast space, which weighs in particular 15 kg. In this case, the safety sensor serves to ensure that the device has a sufficient total weight to apply the test force. The triggering or relevance of the triggering of the safety sensor or at least one of the safety sensors is preferably dependent on the selected test procedure and the test force required for this purpose, in order on the one hand to ensure a sufficient total weight of the device and on the other hand to avoid unnecessary balancing of the device.The device preferably has at least one stand element which serves for depositing or fixing the conductors to be tested. The stator element serves in particular for fixing the conductors to be tested against movement in the test force direction. If the test force direction is oriented vertically, the device has in particular two stand elements which are to be positioned in such a way that the contact element is positioned centrally between the stand elements. The at least one stand element serves in particular for depositing the conductors to be tested at a height of approximately 80 cm. The at least one stand element is preferably arranged on the device frame by means of a flexurally slack connecting element. The flexurally slack connecting element has a length by which the stand element can be easily positioned at the necessary distance from the bearing element without the step of separate measurement.The device preferably has a deflection roller and a flexible tension element. The deflecting roller serves for deflecting the tension element, which connects the contact element to the actuator. The tension element is surrounded by the force transmission device. The stator element for fixing the conductors is in this case configured against a movement in a direction parallel to the contact surface. This embodiment also allows, in the case of a vertical displacement direction and a flat conductor, a testing procedure in which the conductors are to be loaded in their longitudinal direction. The deflected tension element makes it possible for the test force direction to differ from the displacement direction in a simple manner. In particular, the deflection roller and the tension element are optional equipment, by means of which the device is to be converted for different test sequences.Further details and advantages of the invention can be found in the schematically illustrated figures described below; it shows: FIG. 1 shows a schematically illustrated longitudinal section of a device according to the invention with the contact element in the zero position and a conductor, FIG. 2 shows the longitudinal section according to FIG. 1 with the contact element in the test position, FIG. 3 shows a schematically illustrated longitudinal section of a further device according to the invention and of a partly illustrated conductor, FIG. 4 is a schematic longitudinal section of an intermediate frame of the device according to FIG. 3 , FIG. 5 shows a schematic front view of the intermediate frame according to FIG. 4, FIG. 6 shows a schematically illustrated plan view of the intermediate frame according to FIGS. 4 and 5, FIG. 7 is a schematic longitudinal section of the contact element of the device according to FIG. 1 in the state in which it is applied to the conductors, FIG. 8 shows the longitudinal section according to FIG. 7 with the contact element in the state detached from the conductor.The features of the exemplary embodiments described below can also be the subject matter of the invention individually or in combinations other than those illustrated or described, but always at least in combination with the features of claim 1.FIGS. 1 and 2 show a first device 2 according to the invention for testing a conductor 4; the device 2 has a force transmission device 6, which has an abutment element 8 to be applied to the conductors 4 to be tested for transmitting a force directed in a testing force direction PR to the conductors 4 and an actuator 10 coupled to the abutment element 8 and movable for generating the force. In addition, the device 2 has a device frame 26 and rollers 32 with which it is placed on a support surface AF. The ends of the conductors 4 rest on stator elements 22 of the device 2. The apparatus 2 further has a control device, not shown, which comprises a force sensor. The control device is configured to actuate the actuator 10 in such a way that a defined test force can be automatically transmitted to the conductors 4 by means of the contact element 8.The actuator 10 is arranged upright relative to the contact surface AF and is displaceable in a vertical displacement direction VR, which is equal to both the test force direction PR and the distance measuring direction WR. The bearing element 8 is arranged on the actuator 10 by means of a coupling device 12. The coupling device 12 is illustrated in detail by FIGS. 7 and 8. The coupling device 12 has a first coupling partner 14 which is formed by the bearing element 8. Furthermore, the coupling device 12 has a second coupling partner 16 which is formed by the actuator 10. The coupling device 12 is designed such that, in an inoperative state, the bearing element 8 can be pivoted relative to the actuator 10 about a pivot axis SA parallel to the contact surface AF. In detail, the first coupling partner 14 has an elongated hole 18 which is continuous in the direction of the pivot axis SA and extends in an elongated hole direction LR extending transversely thereto. The second coupling partner 16 extends through the slot 18 in a pivotable manner and is displaceable relative to the first coupling partner 14 in the slot direction LR. It can thereby be achieved that the contact element 8, starting from its position according to FIG. 8, can be folded about the pivot axis SA over the illustrated muntin of the ladder 4 and then lowered at least slightly into the position according to FIG. 7 in order to reliably prevent a folding back. For this purpose, the contact element 8 also has a U-shaped mu-shaped muntin receiving space 20, into which the muntin is to be introduced only from the direction of the pivot axis SA.The control device has a travel sensor device with a travel sensor for determining a distance travelled. This is the distance W covered by at least a part of the force transmission device 6 in the distance measuring direction WR. Thus, the control device can determine how far the conductors 4 are deflected by the test force.In detail, the control device is designed for automatic execution of a test sequence. According to this test sequence, the actuator 10 is first moved in the direction of travel VR, i.e. in the direction of the contact surface AF, until the contact element 8 transmits a zero-position force to the conductors 4, i.e. bears against the conductor 4 (cf. FIG. 1 ). The travel sensor device then determines a zero position of the part of the force transmission device 6 while the contact element 8 transmits the zero position force. The actuator 10 is then moved in the travel direction VR until the contact element 8 transmits the defined test force to the conductors 4 (cf. FIG. 2 ). Then, the displacement sensor means detects a check position of the part of the power transmission device 6 while the abutting member 8 transmits the check force. Finally, the travel sensor device determines the distance W covered on the basis of the zero position and the test position.FIGS. 3 to 6 show a further device 2 according to the invention in whole or in part. This device 2 has a stand element 22, which is designed to fix the conductors 4 against movement in a direction parallel to the contact surface AF. In the case of application shown, the bearing element 8 is placed on a hook of the conductors 4 and connected to the actuator 10 via a tension element 24, which is deflected by a deflection roller 28. By this construction, a test procedure other than the prescribed one can be implemented.FIGS. 4 to 6 each show an intermediate frame 30 of the device 2 according to FIG. 3 and a part of the components described above.

Claims

Device (2) for testing conductors, comprising - a force transmission device (6) having an abutment element (8) to be applied to a conductor (4) to be tested for transmitting a force directed in a test force direction (PR) to the conductors (4) and - a force sensor for determining the force, - an actuator (10), which is comprised by the force transmission device (6) and is coupled to the abutment element (8) and can be operated hydraulically, pneumatically or electrically, for generating the force, and - a control device, which comprises the force sensor and is connected to the actuator (10) and is configured for controlling the actuator (10) in such a way that a defined test force can be automatically transmitted to the conductors (4) by means of the abutment element (8), characterized in that, the device frames (26) and rollers (32) mounted on the device frames (26) for moving the device (2), and the device (2) is mobile.Device (2) according to Claim 1, characterized bya travel sensor device, which is included by the control device, for determining a travel (W) covered by at least a part of the force transmission device (6) in a travel measurement direction (WR), which is in particular the same as the test force direction (PR).Device (2) according to Claim 2, characterized bya configuration of the control device for automatically executing a test sequence such that a) the actuator (10) is moved in a first direction (VR) until the bearing element (8) transmits a zero position force, which is less than the test force, to the conductors (4), b) the travel sensor device determines a zero position of the part of the force transmission device (6) while the bearing element (8) transmits the zero position force, c) the actuator (10) is then moved in the first direction (VR) until the bearing element (8) transmits the defined test force to the conductors (4), d) the travel sensor device transmits a test position of the part which during the test force, e) the travel sensor device then determines the distance (W) covered on the basis of the zero position and the test position.Apparatus (2) according to Claim 2 or 3, characterized bya storage unit comprised by the control device and a configuration of the control device such that the distance (W) covered is stored in the storage unit.Device (2) according to one of Claims 2 to 4, characterized bya dispensing device which is comprised by the control device and a configuration of the control device such that different information items are dispensed from the dispensing device depending on the distance (W) covered, in particular also depending on a distance (W) covered during a preceding test.Device (2) according to one of the preceding claims, characterized byan operator input device comprised by the control device and a configuration of the control device such that the actuation of the actuator (10) by means of the operator input device is to be triggered by a user and in particular the test force is to be defined by the operator by means of the operator input device.Device (2) according to claim 6, characterised in that the operator input device is formed by a device relative to the device and / or has a display.Device (2) according to one of the preceding claims, characterized in that the actuator (10) is translationally movable in a direction of travel (VR) which is in particular the same as the direction of testing force (PR) and / or the position measuring direction (WR).Device (2) according to one of the preceding claims, characterized in that the actuator (10) is designed such that it is movable at most over at least 75 mm, in particular over at least 200 mm.Device (2) according to one of the preceding claims, characterized in that the actuator (10) is designed to generate a force of at least 500 N and / or at most 3,000 N, in particular at least substantially 784.8 N or 2,452.5 N.Device (2) according to one of the preceding claims, characterized in that the actuator (10) is arranged at least substantially between the bearing element (8) and a standing surface (AF) in such a way that the direction of travel (VR) is oriented at right angles to the standing surface (AF).Device (2) according to one of the preceding claims, characterized in that the bearing element (8) is arranged on a further part of the actuator (10) by means of a coupling device (12), wherein the coupling device (12) is designed such that the bearing element (8) can be pivoted for the further part, at least in an inoperative state, about a pivot axis (SA), in particular parallel to a contact surface (AF).Device (2) according to claim 12, characterised in that the coupling device (12) comprises a first coupling partner (14) and a second coupling partner (16), wherein the bearing element (8) and the further part each form one of the two coupling partners (14, 16) and the first coupling partner (14) forms an elongate hole (18) which runs continuously in the direction of the pivot axis (SA) and extends elongate in an elongate hole direction (LR) extending transversely thereto and through which the second coupling partner (16) extends pivotably and displaceably relative to the first coupling partner (14) in the elongate hole direction (LR).Device (2) according to one of the preceding claims, characterized in that the bearing element (8) forms a mu- or U-shaped mu-shaped muntin receiving space (20) in a longitudinal section at least partially.Device (2) according to claim 14, characterised in that it is designed to insert a muntin of the ladder (4) into the muntin receiving space (20) from the direction of the pivot axis (SA).Device (2) according to one of the preceding claims, characterized in that the control device comprises at least one safety sensor and is designed in such a way that, when the safety sensor is triggered, the automatic transmission of the test force is prevented.Device (2) according to claim 16, characterised byat least one ballast space for receiving at least one ballast unit, wherein the at least one safety sensor is arranged on the ballast space in such a way that the safety sensor triggers in the event of a lack of ballast unit in the ballast space.Device (2) according to one of the preceding claims, characterized byat least one stand element (22) for depositing or fixing the conductors (4) to be tested, which stand element is preferably arranged on the device (2) by means of a connection element which is limp in bending.Device (2) according to claim 18, characterised bya deflection roller (28) for deflecting a tension element (24) which is surrounded by the force transmission device (6) and which is limp and connects the bearing element (8) to the actuator (10), wherein the stand element (22) is designed for fixing the conductors (4) against a movement in a direction (PR) parallel to a contact surface (AF).

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