A cable exercise device with a torque sensor and a computer-implemented method of its operation

Abstract

This disclosure presents a cable exercise device (10) comprising a stationary part (20), a rotary part (30) and a cable (50). The rotary part (30) comprises magnets (30m) and the stationary part (20) comprises coils (20c) arranged to cooperate with the magnets (30m) to generate a torque between the stationary part (20) and the rotary part (30) and thereby generate a cable load of the cable (50). The stationary part (20) comprises a load bearing portion (22) that is adapted to deflect during operation of the cable exercise device (10) and a strain gauge (24) arranged on the load bearing portion (22) such that the strain gauge (24) is affected by the deflection of the load bearing portion (22). The cable exercise device (10) is configured to determine the torque between the stationary part (20) and the rotary part (30) based on the strain gauge (24). A computer-implemented method (100) is also presented.

Description

[0001] A CABLE EXERCISE DEVICE WITH A TORQUE SENSOR AND

[0002] A COMPUTER-IMPLEMENTED METHOD OF ITS OPERATION

[0003] TECHNICAL FIELD

[0004] The present disclosure generally pertains to motorized training equipment or apparatuses comprising a cable. More particularly, the disclosure relates to a cable exercise device and to a computer-implemented method of operating the device.

[0005] BACKGROUND

[0006] Motorized training involves many benefits for training both in sports and rehabilitation. Motorized training may generally be defined as the utilization of an electric machine to provide controllable resistance or assistance.

[0007] Motorized training equipment comprising a cable for proving a controlled resistance or assistance allows coaches, trainers, and rehab professionals to apply and control resistance across a broad range of foundational exercises and functional movements via the cable.

[0008] Even though there exist apparatuses and equipment that fulfil their intended purposes, there is still room for improvement as regards for example control.

[0009] SUMMARY

[0010] One object of the present disclosure is to provide an improved cable exercise device. For example, typically, prior art devices may not be adapted for precise control of the resistance or assistance, i.e. the cable load. Some prior art devices may not provide for precise control, while others may suffer from slow or unresponsive cable load control.

[0011] According to one aspect of the present disclosure, there is provided a cable exercise device in the form of a sprint exercise device comprising a cable for connection to a person, or in the form of a cable control exercise device for a weight lifting machine. The cable exercise device comprises a stationary part, a rotary part and a cable that is wound in relation to the rotary part such that a rotation of the rotary part results in the cable being fed out or wound in. The rotary part comprises magnets and the stationary part comprises coils arranged to cooperate with the magnets to generate a torque between the stationary part and the rotary part and thereby generate a cable load of the cable. The stationary part further comprises a load bearing portion that is adapted to deflect during operation of the cable exercise device, and a strain gauge arranged on the load bearing portion such that the strain gauge is affected by the deflection of the load bearing portion. The cable exercise device is configured to determine the torque between the stationary part and the rotary part based on the strain gauge. The strain gauge may be referred to as a torque gauge or a torque sensor.

[0012] The present cable exercise device allows for precise and quick determination or measurement of the torque and thus of the cable load. The determined torque may in an advantageous manner be used for controlling the cable exercise device. For example, the determined torque may be used in a feedback control loop to quickly ensure an accurate torque and thus cable load.

[0013] According to a further aspect of the present disclosure, there is provided a computer- implemented method of operating the cable exercise device, the method comprising controlling an electric supply to the coils to generate a desired torque between the stationary part and the rotary part, determining an actual torque between the stationary part and the rotary part based on the strain gauge, comparing the desired torque to the actual torque, and adjusting the electric supply to the coils based on the comparison of the desired torque to the actual torque. In other words, the determined torque may be used in a feedback control loop to quickly ensure an accurate torque and thus cable load.

[0014] There may in addition be provided a computer program product comprising program code for performing, when executed by a processor device, the computer-implemented method. There may in addition be provided a non-transitory computer-readable storage medium comprising instructions, which when executed by the processor device, cause the processing circuitry to perform the computer-implemented method.

[0015] Further features and advantages of the aspects are disclosed in the appended claims and drawings, and in the following description.

[0016] BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The embodiments disclosed herein are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings. Like reference numerals refer to corresponding parts throughout the drawings, in which

[0018] Figure 1 illustrates a stationary part, a rotary part and a cable of a cable exercise device,

[0019] Figure 2 shows the stationary part and the cable of the cable exercise device of figure 1,

[0020] Figure 3 is an enlarged view of the stationary part of figure 2, Figure 4 is a wireframe view corresponding to figure 3,

[0021] Figure 5 shows the stationary part of figure 2,

[0022] Figure 6 shows the stationary part of figure 5 from another angle,

[0023] Figure 7 shows the stationary part partially filled with a vibration damping material,

[0024] Figure 8 shows the stationary part partially filled with vibration damping material to a higher level as compared to figure 7,

[0025] Figure 9 is an exploded view of the stationary part and the rotary part of figure 1,

[0026] Figure 10 corresponds to figure 1 but also shows winded coils of the stationary part,

[0027] Figure 11 shows a sprint exercise device comprising a cable for connection to a person, the sprint exercise device comprising the cable exercise device of the previous figures, and

[0028] Figure 12 illustrates a computer-implemented method of operating the cable exercise device or the sprint exercise device of the previous figures.

[0029] DETAILED DESCRIPTION

[0030] Embodiments of the present disclosure will now be described more fully hereinafter. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those persons skilled in the art.

[0031] Figure 11 shows a sprint exercise device comprising a cable 50 for connection to a person. The sprint exercise device comprises a cable exercise device 10 that is only partly visible in figure 11. The sprint exercise device is portable. The cable exercise device 10 may alternatively be arranged in an undepicted cable control exercise device for a weight lifting machine, the cable exercise device 10 replacing or complementing a weight stack.

[0032] The cable exercise device 10 is illustrated in figures 1 to 10, where not all figures show all components of the cable exercise device 10. Figure 1 illustrates a cable exercise device 10, or at least most of its components that are necessary for an understanding of the present disclosure, comprising a stationary part 20, a rotary part 30 and a cable 50. The latter being wound in relation to the rotary part 30 such that a rotation of the rotary part 30 results in the cable 50 being fed out or wound in. In the present examples, the cable 50 is wound around the rotary part 30, more precisely wound directly around an outer circumferential surface of the rotary part 30.

[0033] The rotary part 30 comprises magnets 30m and the stationary part 20 comprises coils 20c arranged to cooperate with the magnets 30m to generate a torque between the stationary part 20 and the rotary part 30 and thereby generate a cable load of the cable 50. The cable exercise device 10 may function as a three phase alternating current electric machine, or a three phase alternating current electric motor.

[0034] The stationary part 20 comprises a load bearing portion 22 that is adapted to deflect during operation of the cable exercise device 10, and a strain gauge 24 arranged on the load bearing portion 22 such that the strain gauge 24 is affected by the deflection of the load bearing portion 22. The cable exercise device 10 is configured to determine the torque between the stationary part 20 and the rotary part 30 based on the strain gauge 24.

[0035] Referring to figures 7 and 8, the cable exercise device 10 may comprise a vibration damping material 40 arranged in contact with the load bearing portion 22. The vibration damping material 40 may greatly improve the measurement or determination of the torque. In particular, the vibration damping material 40 may reduce the time needed to accurately determine the torque.

[0036] As is illustrated, the load bearing portion 22 may be at least partly embedded in the vibration damping material 40. In the example of figure 8, the load bearing portion 22 is completely embedded in the vibration damping material 40. As may be apprehended from figures 7 and 8, the vibration damping material 40 may be moulded around the load bearing portion 22. The vibration damping material 40 may be casting resin. If the vibration damping material 40 is moulded around the load bearing portion 22, the vibration damping material 40 may be well adhered to the load bearing portion 22 and ensure adequate vibration dampening. Typically, during manufacture of the cable exercise device 10, the stationary part 20 may be oriented such that the vibration damping material 40 may be poured into the stationary part 20 and thereafter left to solidify in the stationary part 20.

[0037] Advantageously, the vibration damping material 40 may have a Shore D value of 25 to 45, measured using ISO 868. A particularly preferred range being 30 to 40.

[0038] The vibration damping material 40 may be a thermosetting polymer material. Such a material may bring advantages in manufacture, as compared to a thermoplastic polymer material. A thermosetting polymer material may also have beneficial vibration damping properties. For one, the thermosetting polymer material may provide for a wide temperature of use, such as from -40 to +135 degrees Celsius.

[0039] In order to provide for use of the cable exercise device 10 outdoors in colder climates, the vibration damping material 40 preferably has a glass transition temperature below 0 degrees Celsius, such as -10 degrees Celsius or -20 degrees Celsius. The vibration damping material 40 may comprise a modulus of elasticity of 10-45 N / mm2(ISO 527-2).

[0040] The vibration damping material 40 may comprise rubber, which may be particularly suitable for damping vibrations. For example, the vibration damping material 40 may comprise natural rubber, ethylene propylene diene monomer, neoprene or polyurethane.

[0041] Tests have shown that a particularly suitable vibration damping material 40 may comprise polyurethane, such as a casting resin polyurethane. The vibration damping material 40 may be a two-component encapsulating resin based on polyurethane. Test have shown that a casting resin polyurethane having a Shore D value of 30-40 (ISO 868), a glass transition temperature of below -20 degrees Celsius is particularly suitable. Such a casting resin polyurethane may have a modulus of elasticity below 45 N / mm2, such 10 to 45 N / mm2. Successful tests have been carried out using WEVOPUR 9251 FL as a vibration damping material 40.

[0042] Referring in particular to figures 2 to 9, the stationary part 20 may comprise a hub portion 20h and a rim portion 20r and at least two load bearing portions 22 functioning as spokes that connect the hub portion 20h and the rim portion 20r. Thus, the load bearing portions 22 may alternatively be referred to as spoke portions, or spokes.

[0043] A circumferential force is generated between the coils of the stationary part 20 and the magnets 30m of the rotary part 30. The coils are typically wound on T-shaped slots, see figure 1. The circumferential force generates a torque between the rotary part 30 and the stationary part 20. The torque is then transferred via the slots to the rim portion 20r, and further via the load bearing portions 22 to the hub portion 20h. Thus, the torque between the rotary part 30 and the stationary part 20 results in a deflection of the load bearing portions 22.

[0044] As is shown in figures 7 and 8, the vibration damping material 40 may be arranged in contact with the hub portion 20h and the rim portion 20r, more precisely, the vibration damping material 40 may be moulded between the hub portion 20h and the rim portion 20r. In addition, as described and shown, the load bearing portions or spokes 22 may be at least partly embedded in the vibration damping material 40. During moulding, the stationary part 20 may be oriented with the rotational axis A (denoted in figure 9) aligned with the vertical direction, see figures 7 or 8, and the vibration damping material 40 may be poured to at least partially fill the space between the hub portion 20h and the rim portion 20r. A cover portion or temporal lid may be arranged at the bottom of the stationary part 20 to contain the vibration damping material 40 before curing thereof.

[0045] As is illustrated, the rim portion 20r may comprise at least one rim shape irregularity 20rs (denoted in figures 5 and 7) that is adapted to engage the vibration damping material 40 in a form-fit. The rim shape irregularity 20rs may for example be a protrusion or a depression in the rim portion 20r. Referring to figure 5, the hub portion 20h may alternatively, or in addition, comprise at least one hub shape irregularity 20hs that is adapted to engage the vibration damping material 40 in a form-fit. Tests have shown that such shape irregularities may improve the vibration damping. Such shape irregularities 20rs, 20hs may connect the rim portion 20r and the hub portion 20h in a form-fit via the vibration damping material 40.

[0046] In the present examples, there is a generally annular cavity between the rim portion 20r and the hub portion 20h, and the generally annular cavity is at least partly filled with the vibration damping material 40.

[0047] Referring in particular to figures 2 to 6, the load bearing portion 22 may comprise a deformation instruction 26 where the strain gauge 24 is arranged. The load bearing portion 22 may, by means of the deformation instruction 26, be adapted such that the deflection of the load bearing portion 22 mainly occurs where the strain gauge 24 is arranged. Thereby, the accuracy of the torque determination may be ensured. Herein, an example of a deformation instruction 26 design is shown, it is to be apprehended that other designs of the deformation instruction and of the load bearing portion 22 are plausible.

[0048] In the present examples, the deformation instruction 26 is a cavity. The cavity is made in the load bearing portion 22. As is shown, the cavity may essentially have the form of a rectangular block, see in particular figure 4. The present load bearing portion 22 essentially has a rectangular cross-section. Further, the radial length of the present load bearing portion 22 is approximately 1.5 to 3 times its width (in the circumferential direction). The cavity may occupy approximately 40 to 60 percent of the radial length of the load bearing portion 22. The, in radial cross-section, essentially rectangular load bearing portion 22, with the rectangular block cavity, leaves a load bearing portion wall 20w of reduced thickness where the strain gauge 24 may advantageously be arranged. The cavity may be referred to as a blind hole.

[0049] The load bearing portion 22 is weakened by the deformation instruction 26, such that a deflection of the load bearing portion 22 mainly occurs where the cavity is positioned. The deflection of the load bearing portion 22 may alternatively be referred to as a deformation of the load bearing portion 22. Typically, the deflection of the load bearing portion 22 is a bending thereof. The load bearing wall 20w formed by the deformation instruction 26 is a section of the load bearing portion that has been weakened by the deformation instruction 26. In other words, the load bearing wall formed by the deformation instruction 26 is a section of the load bearing portion that comprises a smaller cross-section as a result of the cavity. During the deflection, the section of the load bearing portion where the strain gauge 24 is arranged may e.g. change shape from a square to a rhombus, or from a rectangle to a parallelogram.

[0050] Referring to figure 7, the deformation instruction 26, or cavity, may be partly filled with a vibration damping material 40. Referring to figure 8, the deformation instruction 26, or cavity, may be completely filled with a vibration damping material 40.

[0051] In the present examples, the strain gauge 24 is a shear strain gauge. Such a strain gauge 24 may be particularly beneficial for accurate torque determination. Referring to figures 1, 3, 4 and 9, the strain gauge 24 may be arranged on a surface of the load bearing portion 22 that is aligned with a plane P (illustrated in figure 9) that is normal to a rotational axis A illustrated in figure 9) of the rotary part 30. Such an arrangement may be beneficial for using a shear strain gauge. During the deformation or deflection of the load bearing portion 22, the surface of the load bearing portion where the strain gauge 24 is arranged may change shape from a square to a rhombus, or from a rectangle to a parallelogram. Said change of shape may be measured or monitored by the shear strain gauge.

[0052] Typically, the thickness t of the load bearing portion 22 where the strain gauge 24 is arranged is 5 to 20 percent of the nominal thickness T of the load bearing portion 22. In the present example, the thickness t may be 0.7 to 1.0 millimeters.

[0053] As shown in figure 1 (even though two out the fours spokes are partially obscured), the stationary part 20 comprises four load bearing portions 22 functioning as spokes, and strain gauges 24 arranged on two opposite load bearing portions 22. An even better accuracy could be achieved by arranging strain gauges 24 of each one of the four load bearing portions 22, but strain gauges 24 on two opposite load bearing portions 22 are more cost-effective and still provide high accuracy. The present disclosure does not exclude there being other numbers of load bearing portions 22, but for accuracy it is believed beneficial to arrange strain gauges 24 on two radially opposite load bearing portions 22.

[0054] The present spokes or load bearing portions 22 are of a rectangular cross-section and have a larger extension in a circumferential direction than in an axial direction. Such a design may be light-weight and may provide for a shear deformation where the shear strain gauge is arranged. Load bearing portions 22 of square or rectangular cross-section are believed most suitable for use together with shear strain gauges, arranged as illustrated e.g. in figure 3 (in plane P shown in figure 9).

[0055] In one preferred example, the cable exercise device 10 comprises a stationary part 20, a rotary part 30 and a cable 50. The cable 50 is wound in relation to the rotary part 30 such that a rotation of the rotary part 30 results in the cable 50 being fed out or wound in. The rotary part 30 comprises magnets 30m and the stationary part 20 comprises coils 20c arranged to cooperate with the magnets 30m to generate a torque between the stationary part 20 and the rotary part 30 and thereby generate a cable load of the cable 50. The stationary part 20 comprises a load bearing portion 22 that is adapted to deflect during operation of the cable exercise device 10 and strain gauge 24 arranged on the load bearing portion 22 such that the strain gauge 24 is affected by the deflection of the load bearing portion 22, wherein the cable exercise device 10 is configured to determine the torque between the stationary part 20 and the rotary part 30 based on the strain gauge 24. The cable exercise device 10 comprises a vibration damping material 40 arranged in contact with the load bearing portion 22, wherein the load bearing portion 22 is completely embedded in the vibration damping material 40. The vibration damping material 40 is moulded around the load bearing portion 22, has a Shore D value of 25 to 45 and a glass transition temperature below -10 degrees Celsius. The strain gauge 24 is arranged on a surface of the load bearing portion 22 that is aligned with a plane P that is normal to a rotational axis A of the rotary part 30.

[0056] Referring to figure 12, a computer-implemented method 100 of operating the cable exercise device 10 will next be described. The method 100 comprises controlling 110 an electric supply to the coils 20c to generate a desired torque between the stationary part 20 and the rotary part 30. As mentioned, the cable exercise device 10 may function as a three phase alternating current electric machine known per se to persons skilled in the art of cable exercise devices. Therefore, no detailed description on the electric supply is provided herein. In brief, the cable exercise device 10 may comprise a battery and a controller for supplying electricity to the the coils 20c.

[0057] The method 100 further comprises determining 120 an actual torque between the stationary part 20 and the rotary part 30 based on the strain gauge 24. Strain gauges, such as shear strain gauges, and their operation are well known to persons skilled in the art of cable exercise devices and therefore no detailed description on the strain gauge is provided herein. In brief, the strain gauge may comprise a metal element having a deformation dependent electrical resistance. The deformation dependent electrical resistance is utilised to determine the deformation of the strain gauge and thereby of an element (the load bearing portion) on which the strain gauge is arranged.

[0058] The method 100 further comprises comparing 130 the desired torque to the actual torque. For various reasons, it may typically be that case that the actual torque, obtained by means of the strain gauge 24, differs from the desired torque that was aimed at by the controller.

[0059] Next, the method 100 comprises comparing adjusting 140 the electric supply to the coils 20c based on the comparison of the desired torque to the actual torque. Thereby, the desired torque may be obtained. The method 100 may run as a feedback control loop essentially continuously ensuring that the actual torque equals, or at least substantially equals, the desired torque.

[0060] Especially when the cable exercise device 10 comprises the vibration damping material 40, tests have shown that the method 100 may quickly ensure a highly accurate torque.

[0061] As is illustrated, the stationary part 20 may be a one-piece component. Typically, the stationary part 20 may be made of aluminium (aluminum in North American English), magnesium or polymer material. As is to be apprehended, by aluminium is typically not meant pure aluminum but an aluminum alloy. The stationary part 20 of the present examples is manufactured from a single block of aluminium.

[0062] As mentioned, the cable exercise device 10 may function as a three phase alternating current electric machine. The rotary part 30 of the cable exercise device 10 may be referred to as a rotor. The stationary part 20 of the cable exercise device 10 may be referred to as a stator.

[0063] Modifications and other variants of the described embodiments will come to mind to ones skilled in the art having benefit of the teachings presented in the foregoing description and associated drawings. Therefore, it is to be understood that the embodiments are not limited to the specific example embodiments described in this disclosure and that modifications and other variants are intended to be included within the scope of this disclosure. Still, figure 11 shows one possible actual implementation of the sprint exercise device, and figures 1 to 10 show possible actual implementations of the cable exercise device.

[0064] Furthermore, although specific terms may be employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. Therefore, persons skilled in the art would recognize numerous variations to the described embodiments that would still fall within the scope of the appended claims. As used herein, the terms “comprise / comprises” or “include / includes” do not exclude the presence of other elements or steps. Furthermore, although individual features may be included in different claims (or embodiments), these may possibly advantageously be combined, and the inclusion of different claims (or embodiments) does not imply that a certain combination of features is not feasible and / or advantageous. In addition, singular references do not exclude a plurality. Finally, reference numerals in the claims are provided merely as a clarifying example and should not be construed as limiting the scope of the claims in any way.

Claims

CLAIMS1. A cable exercise device (10), the cable exercise device (10) being a sprint exercise device comprising a cable for connection to a person, or a cable control exercise device for a weight lifting machine, the cable exercise device (10) comprising a stationary part (20), a rotary part (30), and a cable (50) that is wound in relation to the rotary part (30) such that a rotation of the rotary part (30) results in the cable (50) being fed out or wound in, the rotary part (30) comprising magnets (30m) and the stationary part (20) comprising- coils (20c) arranged to cooperate with the magnets (30m) to generate a torque between the stationary part (20) and the rotary part (30) and thereby generate a cable load of the cable (50),- a load bearing portion (22) that is adapted to deflect during operation of the cable exercise device (10), and- a strain gauge (24) arranged on the load bearing portion (22) such that the strain gauge (24) is affected by the deflection of the load bearing portion (22), wherein the cable exercise device (10) is configured to determine the torque between the stationary part (20) and the rotary part (30) based on the strain gauge (24).

2. The cable exercise device (10) of claim 1, comprising a vibration damping material (40) arranged in contact with the load bearing portion (22).

3. The cable exercise device (10) of claim 2, wherein the load bearing portion (22) is at least party embedded in the vibration damping material (40).

4. The cable exercise device (10) of claim 2, wherein the load bearing portion (22) is completely embedded in the vibration damping material (40).

5. The cable exercise device (10) according to any one of claims 2 to 4, wherein the vibration damping material (40) is moulded around the load bearing portion (22).

6. The cable exercise device (10) according to any of claims 2 to 5, wherein the vibration damping material (40) has a Shore D value of 25 to 45.

7. The cable exercise device (10) according to any of claims 2 to 6, wherein the vibration damping material (40) is a thermosetting polymer material.

8. The cable exercise device (10) according to any of claims 2 to 7, wherein the vibration damping material (40) has a glass transition temperature below 0 degrees Celsius.

9. The cable exercise device (10) according to any of claims 2 to 8, wherein the vibration damping material (40) comprises rubber.

10. The cable exercise device (10) according to any of claims 2 to 9, wherein the vibration damping material (40) comprises natural rubber, ethylene propylene diene monomer, neoprene or polyurethane.

11. The cable exercise device (10) according to any of claims 2 to 10, wherein the vibration damping material (40) comprises polyurethane.

12. The cable exercise device (10) of any preceding claim, wherein the stationary part (20) comprises a hub portion (20h) and a rim portion (20r) and at least two load bearing portions (22) functioning as spokes that connect the hub portion (20h) and the rim portion (20r).

13. The cable exercise device (10) of claim 12, comprising a vibration damping material (40) arranged in contact with the hub portion (20h) and the rim portion (20r).

14. The cable exercise device (10) of claim 12 or 13, comprising a vibration damping material (40) that is moulded between the hub portion (20h) and the rim portion (20r).

15. The cable exercise device (10) of claim 13 or 14, wherein the rim portion (20r) comprises at least one rim shape irregularity (20rs) that is adapted to engage the vibration damping material (40) in a form-fit.

16. The cable exercise device (10) according to any of claims 13 to 15, wherein the hub portion (20h) comprises at least one hub shape irregularity (20hs) that is adapted to engage the vibration damping material (40) in a form-fit.

17. The cable exercise device (10) of any preceding claim, wherein the load bearing portion (22) comprises a deformation instruction (26) where the strain gauge (24) is arranged.

18. The cable exercise device (10) of claim 17, wherein the deformation instruction (26) is a cavity.

19. The cable exercise device (10) of claim 18, wherein the cavity is substantially filled with a vibration damping material (40).

20. The cable exercise device (10) of any preceding claim, wherein the strain gauge (24) is a shear strain gauge.

21. The cable exercise device (10) of claim 20, wherein the strain gauge (24) is arranged on a surface of the load bearing portion (22) that is aligned with a plane (P) that is normal to a rotational axis (A) of the rotary part (30).

22. The cable exercise device (10) of claim 21, wherein the thickness (t) of the load bearing portion (22) where the strain gauge (24) is arranged is 5 to 20 percent of the nominal thickness (T) of the load bearing portion (22).

23. The cable exercise device (10) of any preceding claim, wherein the stationary part (20) comprises a hub portion (20h) and a rim portion (20r) and four load bearing portions (22) functioning as spokes that connect the hub portion (20h) and the rim portion (20r), and strain gauges (24) arranged on two opposite load bearing portions (22).

24. The cable exercise device (10) of any preceding claim, wherein the load bearing portions (22) are of a rectangular cross-section and have a larger extension in a circumferential direction than in an axial direction.

25. The cable exercise device (10) of claims 4, 5, 6 and 21, wherein the glass transition temperature of the vibration damping material (40) is below -10 degrees Celsius.

26. A computer-implemented method (100) of operating the cable exercise device (10) of any preceding claim, the method (100) comprising controlling (110) an electric supply to the coils (20c) to generate a desired torque between the stationary part (20) and the rotary part (30), determining (120) an actual torque between the stationary part (20) and the rotary part (30) based on the strain gauge (24), comparing (130) the desired torque to the actual torque, andadjusting (140) the electric supply to the coils (20c) based on the comparison of the desired torque to the actual torque.

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