AUXILIARY DRIVE FOR A TRAINING EQUIPMENT

Description

[0001] The invention relates to an auxiliary drive for a training device, which comprises at least a first force measuring device, a control device and a drive unit, and to a system which comprises the training device and the auxiliary drive for the training device.

[0002] Using the auxiliary drive for the training device according to the invention, both an existing training device, in particular a strength training device, can be retrofitted relatively easily, and a new training device can be equipped accordingly during assembly. The auxiliary drive according to the invention can also be dismantled non-destructively, so that it can subsequently be used, for example, in another training device. The quasi-modular design of a system comprising the auxiliary drive and the strength training device also offers manufacturers increased flexibility in production. Furthermore, the auxiliary drive can, of course, be manufactured and offered completely separately.

[0003] Document US2010279821A1 discloses an auxiliary drive for a training device according to the preamble of claim 1.

[0004] As an example, strength training equipment is described in which the total movable mass can essentially be formed by several mass plates arranged vertically one above the other. These mass plates are connected via a connecting rod and a pin, which are then moved accordingly and define the total movable mass accordingly.

[0005] Therefore, assuming a specific / known acceleration, the maximum training resistance is defined by setting the total movable mass, for which the pin is attached accordingly. As a rule, when the exerciser applies a force, this acceleration of the total movable mass is directed opposite to the acceleration due to gravity.

[0006] Conventional strength training machines, which are purely mechanical in design, have the disadvantage that the training resistance can only be adjusted at discrete intervals, namely according to the mass of the individual weight plate (for example, 5 kg each). Each such adjustment must be made actively, usually by switching the pin, making it virtually impossible to apply a different load during the concentric and eccentric phases. Likewise, continuous adaptation to the user's cardiovascular values ​​is hardly possible.Active training equipment (fully electric strength training equipment) that can generate dynamic resistance purely electrically also offers the training options mentioned above, but they are significantly more expensive both to purchase and to maintain and require complex safety measures to prevent overloading of the user in the event of a malfunction. The power consumption of such active training equipment is also significantly higher than that of the auxiliary drive according to the invention.

[0007] The object of the invention is therefore to provide an auxiliary drive for a training device and a system comprising the training device and the auxiliary drive for the training device in order to enable safe and optimized loading.

[0008] As described above, assuming a certain / known acceleration, the maximum training resistance is well defined by determining the total movable mass. When the trainee intentionally applies a force, the resulting acceleration of the total movable mass is directed opposite to the acceleration due to gravity.

[0009] This serves a twofold safety purpose. Firstly, a secure mechanical connection between the mass plates and the rest of the movable mechanism of the training device can be established relatively easily. Secondly, the total movable mass is well-defined, namely essentially by the mass plates connected to each other by means of the pin. The maximum training resistance defined by setting the total movable mass – which requires a specific / known acceleration – cannot therefore be inadvertently or unexpectedly exceeded, since due to the total movable mass, the trainee must always apply a maximum force equal to the product of the total movable mass and the desired acceleration against the acceleration due to gravity.The auxiliary drive according to the invention for the training device can therefore only apparently reduce the total movable mass and the resulting load from the perspective of and with effect for the training person, but never actually increase it.

[0010] The auxiliary drive for training equipment according to the invention retains precisely these two essential safety features, in particular the maximum possible (intended) training resistance, which is well defined by the total movable mass. Due to its design, the auxiliary drive for training equipment according to the invention offers the particular advantage that the maximum possible training resistance, which is well defined by the total movable mass, can be reached but never inadvertently exceeded. To this end, the auxiliary drive according to the invention always acts on the total movable mass in such a way that at least one component of the resulting force acts counter to the acceleration due to gravity, i.e., counter to the acceleration due to gravity or gravity due to fall.

[0011] This is also one of the main advantages of the present invention over active training equipment (fully electric strength training equipment), which can generate dynamic resistance purely electrically. Such equipment also requires a very high level of safety to prevent excessive strain or even potential injury in the event of a fault. In general, the costs of both purchasing and maintaining active training equipment (fully electric strength training equipment) are very high.

[0012] Using the auxiliary drive for the training device according to the invention, the actual force to be applied, and thus the load, can be continuously adjusted during the exercise, while ensuring safe maintenance of the set maximum training resistance. In the simplest case, a maximum load can be set with any finely graduated values, which can correspond at most to the maximum training resistance specified by the total movable mass. Such a maximum load can also be adjusted during the execution of an exercise. A purely temporal adjustment or an adjustment based on a predetermined cycle, which can also take into account the cardiovascular values ​​of the exerciser, is conceivable.

[0013] Another very important advantage of the auxiliary drive according to the invention is its ability to generate a so-called "eccentric overload." Eccentric overload occurs during a movement phase when the muscle is stretched (eccentric contraction) and experiences a greater load than it was previously exposed to in the concentric movement phase, which shortens the muscle (active muscle shortening; concentric contraction), or than it would be exposed to during a sustained lengthening against resistance (isometric contraction). In a standard weight-stacked strength training device, the eccentric contraction and the concentric contraction would ideally be equal, but due to frictional losses, the force in the concentric phase is always slightly higher than in the eccentric phase.However, since the muscles could be subjected to up to 30% higher loads, especially during eccentric contraction, the corresponding training stimulus for the muscles is lost, which in turn only triggers reduced muscle growth.

[0014] The fluid load control during a movement enabled by the auxiliary drive according to the invention also allows the force curves to be optimally adjusted to the leverage ratios of an exercise and the trainee. It is also possible to recognize when a trainee should adjust their load. This also enables, for example, automated training load adjustments.

[0015] The auxiliary drive according to the invention can be designed as a conversion kit in such a way that only additional elements are mounted, but no mechanical changes need to be made to the existing mechanism or to a cover or any power-transmitting part of the existing strength training device. Furthermore, no pull ropes or weight plates need to be dismantled, and no specialist personnel trained in electrical or electronic systems are required to commission the device and monitor it during normal operation. Due to the type of attachment and the basic functioning of the auxiliary drive according to the invention, as described above, the user cannot be subjected to any mechanical stress greater than the adjustable maximum training resistance, the range of which is already predetermined by the manufacturer through the weight plate configuration.This also helps avoid problems with product liability or existing warranty claims.

[0016] It is also advantageous that the mechanics of the auxiliary drive according to the invention can be formed from a series of common machine elements, which can reduce the costs for, among other things, acquisition, operation, maintenance, upkeep and replacement.

[0017] To achieve the object, an auxiliary drive for a training device is proposed which has the features mentioned in claim 1.

[0018] Such an auxiliary drive for the training device can comprise at least a first force measuring device, at least one control device, and at least one drive unit. The control device can determine a target force, FS,max , which should correspond to the maximum load of the trainee. This target force, FS,max , can be variable both over time and with regard to additionally determined variables; such a change can be continuous, almost discrete, and / or cyclical. The target force, FS,max , can be determined, for example, as a function of a direction of movement, a speed of movement, a change in the speed of movement, a value of the trainee's cardiovascular system, or a combination thereof; a variety of physiological values ​​are conceivable that can be included in the calculation of the target force, FS,max .The first force measuring device can determine an actual force, FS , which can be applied to a main traction device of the training device, on which the trainee acts, and which can essentially be caused by an acceleration of a movable mass connected to the main traction device. Such a main traction device can be, for example, a rope or a belt, i.e. a machine element suitable for transmitting a tensile force. This acceleration of the movable mass can be either the constantly acting acceleration due to gravity or acceleration due to gravity – i.e. the essentially constant acceleration due to gravity – or an additional dynamic acceleration caused by the trainee. The actual force, FS , determined at the main traction device can be transmitted from the first force measuring device to the control device.The control device can then compare the transmitted actual force, FS , with the desired force, FS,max , and - if the actual force, FS , exceeds the desired force, FS,max , - the control device can control the drive unit in such a way that, by connecting the drive unit to the movable mass, an auxiliary force, FZ , can act on the movable mass, which auxiliary force has a component counter to the acceleration due to gravity.

[0019] Since the control device only activates the drive unit when the actual force, FS , measured on the main traction device exceeds the target force, FS,max , the load for the trainee can never be greater than the load resulting from the movable mass and the total acceleration acting on it. If the trainee does not apply a load that leads to an actual acceleration of the movable mass against the acceleration due to gravity, the maximum acceleration of the movable mass is the acceleration due to gravity. Therefore, if at least one component of the auxiliary force, FZ , acts against the acceleration due to gravity, it is guaranteed that the trainee can never unexpectedly experience a potentially dangerously high load. This protection can also be further increased by intentionally limiting the auxiliary force absolutely or relative to the movable mass; for example, to a maximum of 150 N or 20% of the movable mass.Since the auxiliary force (FZ) can be limited with a fully functioning auxiliary drive for the training device, even assuming a complete system failure, the additional load cannot exceed the lost limited auxiliary force (FZ) and thus, for example, can only amount to a maximum of 20% of the movable mass. In addition to increased safety, this also prevents increased power consumption.

[0020] Furthermore, such an auxiliary drive for the training device can provide an emergency braking function for the drive unit. In the event of a power failure or other malfunction, a hardware-implemented safety emergency stop function can be integrated, which can then short-circuit the windings of an electric motor in the drive unit. This allows the moving mass to be braked with the maximum torque of the electric motor in the event of a fault or in the event of disproportionately deviating measured values, for example, exceeding a limit value.

[0021] The dependent claims relate to advantageous embodiments and further developments of the invention.

[0022] In the auxiliary drive, the control device can compare the transmitted actual force, FS , with the target force, FS,max , and, if the actual force, FS , exceeds the target force, FS,max , the control device can actuate the drive unit in such a way that, by connecting the drive unit to the movable mass, the auxiliary force, FZ , reduces the determined actual force, FS , applied to the main traction device. This can verifiably ensure that the actual force, FS , applied to the main traction device has actually been reduced by the auxiliary force, FZ , thereby increasing safety.

[0023] With the auxiliary drive, the control device can compare the transmitted actual force, FS , with the target force, FS,max , and, if the actual force, FS , exceeds the target force, FS,max , the control device can control the drive unit in such a way that, by connecting the drive unit to the movable mass, the auxiliary force, FZ , reduces the determined actual force, FS , applied to the main traction device essentially to the target force, FS,max . This can verifiably ensure that the force to be applied by the trainee now essentially corresponds to the target force, FS,max , for example apart from existing friction losses. If the target force, FS,max , changes, the actual force, FS , also changes accordingly due to the control, since the auxiliary force, FZ , is constantly adjusted.While maintaining all the positive safety features described above, a load for the trainee that can be adjusted and optimized almost as desired can be created.

[0024] The auxiliary drive can additionally comprise a motion sensor, which can be configured to determine a direction of movement of the movable mass and transmit it to the control device. The control device can further be configured to determine the target force, FS,max , additionally depending on the direction of movement of the movable mass. This can, for example, generate the "eccentric overload" described above, which can lead to improved muscle development, since the load to be applied by the exerciser can be positively adapted to the current direction of movement.

[0025] The motion sensor of the auxiliary drive can further be configured to determine an absolute or relative position of the movable mass and / or its first and / or second temporal derivative, or a correspondingly proportional variable thereto, and to transmit it to the control device. The control device can further be configured to determine the target force, FS,max , additionally as a function of the position of the movable mass and / or its first and / or second temporal derivative. This enables an even finer adjustment of the target force, FS,max , to relevant parameters, so that the training effect can be increased due to the improved and, in particular, refined progressions.

[0026] Advantageously, the motion sensor can be integrated into the drive unit, ensuring both a particularly space-saving design and exceptional protection against potential external damage. Furthermore, the integrity of the measurement can be increased if the motion sensor performs the measurement directly in the drive unit, thus eliminating the involvement of other machine elements that could distort the measurement.

[0027] Furthermore, the first force measuring device of the auxiliary drive can be configured to determine the actual force, FS, by measuring a tension of the main traction mechanism. In principle, with a known tension, the actual force, FS, can be determined very precisely, which also increases the precision of the control resulting from the comparison with the target force, FS,max.

[0028] Advantageously, the first force measuring device can be configured to determine the tension of the main traction element using a deflection. This represents a particularly reliable method for determining the tension and thus the actual force applied, FS, which in turn increases the reliability of the control resulting from the comparison with the target force, FS,max.

[0029] Furthermore, the first force measuring device can be configured to determine the actual force, FS, by detecting an extension of the main tension member. The actual force, FS, can also be determined very precisely from an extension.

[0030] Since in the linear-elastic range (proportional range, "Hooke's line") the strain is proportional to the stress and thus Hooke's law applies, both methods of determining the actual force, FS, can be performed either alternatively or in parallel. If two measured values ​​of the actual force, FS, are available, determined in different ways, they can be compared appropriately, which can further increase the integrity of the measurement. An assessment of the suitability of the measurement method with regard to the rate of change of the measured values ​​or the dynamics in general is also conceivable.

[0031] Advantageously, the first force measuring device can be a strain gauge and / or a magnetostrictive sensor that operates according to the principle of magnetostriction. Both strain gauges and magnetostrictive sensors are available from common suppliers in a wide variety of designs, thus well-adapted to specific needs, which can also reduce costs. In addition, strain gauges, in particular, are very space-saving and can be easily installed even in hard-to-reach places.

[0032] Furthermore, the first force measuring device can be configured to determine the actual force, FS , by comprising a weighing device that can be configured to determine the mass of the movable mass and by further comprising an acceleration sensor that can be configured to determine a second temporal change in a position of the movable mass. With knowledge of the accelerated mass and knowledge of the corresponding acceleration, the actual force, FS , can be determined directly from Newton's second law by simple multiplication. For this purpose, the weighing device must, for example, measure a difference between a weight force in the case where the movable mass is only resting under the influence of gravitational acceleration and in the case where the movable mass is not resting, at a location at which it can be detected that the movable mass is in contact.As already described above, several ways of determining the actual force, FS , can be carried out both alternatively to one another and in parallel. If two or more measured values ​​of the actual force, FS , determined in different ways are available, these can be compared with one another in a suitable manner, whereby the integrity of the measurement can be further increased. In general, the present invention considers it extremely advantageous if - quite generally - determined quantities are determined in different ways and / or multiple times; sensor data fusion can also be used for this purpose. As mentioned above, the dynamics of the underlying movement can be important in the sensor data fusion, as can the dynamics of the determined values ​​themselves.

[0033] Advantageously, the acceleration sensor can be a motion sensor that can be configured to determine the absolute or relative position of the movable mass and its first and second temporal derivatives, or a correspondingly proportional value. It is conceivable that the motion sensor described above is used in the configuration described here, or that an additional motion sensor is used, whose data can then be used in addition to that of the existing motion sensor and from which additional measured values ​​can also be determined, particularly after sensor data fusion.

[0034] Furthermore, in the auxiliary drive, the connection of the drive unit to the movable mass can act at a first point on the main traction means, which is closer to the movable mass than a second point on the main traction means, at which the first force measuring device determines the actual force, FS . This ensures that the actual force, FS , determined by the first force measuring device, which is applied to the main traction means of the training device and is essentially applied by the user, cannot be distorted in the force flow within the main traction means. If the drive unit acts at the first point on the main traction means according to the invention, a particularly compact design of the auxiliary drive can be achieved.

[0035] Furthermore, the drive unit can include a generator, which, especially in the case of eccentric movement, makes it possible not only to avoid energy consumption but even to recover energy, since the generator, for example, provides the required braking torque to generate the corresponding auxiliary force, FZ. Since energy consumption can be reduced in this way, any existing batteries / accumulators can also be smaller and less expensive.

[0036] Advantageously, the auxiliary drive can additionally comprise a second force measuring device configured to determine the auxiliary force, FZ, acting on the movable mass and / or to determine the work effectively performed by the drive unit. This makes it possible to check the control of the drive unit, increase the precision of the control, and improve error detection. Vibrations can also be more easily avoided in areas where the control could unintentionally cause vibration. The second force measuring device can also be integrated into the drive unit, enabling a compact, protected design, increasing the integrity of the measurement, and enabling comparatively simple force-displacement determination. Similar to the first force measuring device, the second force measuring device can also comprise a magnetostrictive sensor.

[0037] Furthermore, the auxiliary drive can additionally comprise an operating unit which can be configured to transmit data to the control device from which the control device can additionally determine the target force, FS,max . A variety of embodiments are conceivable here. In principle, the operating unit can be configured to specify the target force, FS,max , and in particular also its curve or its change. For example, a number of different training programs can be selected from which the respectively valid target force, FS,max , is then determined. A comparatively simple control device can also be used here which, in addition to the curves of the target force, FS,max , received from the operating unit, performs no or only a limited amount of further calculations in order to determine the target force, FS,max .

[0038] In addition, the control device can be further configured to transmit data to the control unit and / or to an IT infrastructure and to receive data from the IT infrastructure. The control unit can also be configured to receive data from an external measuring unit and / or data from the IT infrastructure and / or to transmit it to the IT infrastructure. This makes it possible, for example, to show the trainee how best to follow target courses. Furthermore, results can be transmitted to the control unit to ensure that a selected goal can be verified. Furthermore, the data can also be transmitted to the IT infrastructure, such as a computer or a cloud, for analysis and evaluation. In particular, the temporal development of a trainee can be clearly displayed and verified, and any necessary adjustments can be made.Advantageously, statically or dynamically determined parameters of the trainee can also be recorded via the control unit, either by input or by data forwarding to the control device, or the corresponding calculations can be performed in the control unit itself. In addition to the trainee's height and weight, for example, cardiovascular values ​​are also conceivable, which are suitable for determining an appropriate training plan. The specifications for the ultimately generated target force curves, FS,max , can also come from a (possibly second) IT infrastructure, such as a computer or a cloud. However, they can also be generated in the control unit itself or in the control device.The adjustment of the target force, FS,max , can also occur continuously: For example, the IT infrastructure can receive the determined cardiovascular values ​​from the control unit, along with the data transmitted by the control device to the control unit. The IT infrastructure can then, in turn, make a corresponding adjustment of the target force, FS,max , and transmit this data to the control unit via the control unit. Therefore, restrictions to a single specific structure are not necessary.

[0039] The fundamental redundancy for determining the target force, FS,max , can be considered particularly advantageous, since different units can be particularly suitable depending on the (current) data availability and computing power.

[0040] Advantageously, the auxiliary drive can further comprise an auxiliary traction cable, which is directly or indirectly connected to both the drive unit and the movable mass, thus establishing the connection between the drive unit and the movable mass. This direct connection can be considered particularly simple and therefore less prone to failure. The auxiliary traction cable, along with a belt, can be particularly suitable for establishing a space-saving and secure connection between the drive unit and the movable mass. A wide variety of cables are designed and available as standard for a wide range of requirements, thus keeping costs within limits. A hydraulic connection would also be conceivable, as would other mechanical connections – for example, using a gearbox.

[0041] In addition, the drive unit can be designed as a cable drum, allowing the auxiliary traction cable to be wound up in a particularly space-saving and secure manner. This protects against potential damage and also prevents unwanted contact with other elements, such as the main traction device—especially when a relatively long section of the auxiliary traction cable has been wound up.

[0042] Particularly advantageously, the drive unit can also be configured to always provide sufficient torque to wind up the auxiliary pull rope, whereby safety can be further increased because, due to the tension prevailing in the auxiliary pull rope, the probability of contact with other elements can be minimized and, furthermore, the response behavior can be further improved, in particular due to the lack of play.

[0043] The invention also relates to a system that can comprise a training device and an auxiliary drive for the training device with the features described above. The movable mass can comprise one or more weight plates that can be connected by means of a connecting bar and a pin and can be movable in two substantially parallel guide rods. The movable mass can be connected to the main traction device via the connecting bar. This allows the total movable mass to be defined particularly simply and reliably, and also ensures its safe guidance.

[0044] Advantageously, the auxiliary drive of the system can additionally comprise two outer deflection pulleys and two rear deflection pulleys, which can be connected to the movable mass by a first and a second connecting device, furthermore a first upper clamping device, which can be frictionally attached to one of the two parallel guide rods, and a second upper clamping device, which can be frictionally attached to the other of the two parallel guide rods, wherein the first upper clamping device can receive a first end of the auxiliary traction cable, the auxiliary traction cable can be guided through the two outer deflection pulleys and through the two rear deflection pulleys, and the drive unit can receive a second end of the auxiliary traction cable.As a result, the drive unit can act on the movable mass in such a way that it can be guided parallel to the two parallel guide rods without generating a resulting and therefore braking moment. This reduces friction and therefore resistance and also wear and tear, and therefore enables increased precision in the controlled load on the trainee. According to the invention, the drive unit then only has to apply half the total auxiliary force, FZ, acting on the movable mass, which is why it can also be more compact. Of course, the correspondingly determined sizes must be adapted. In addition to the drive unit, which can accommodate the second end of the auxiliary pull cable, the auxiliary drive can further comprise a second drive unit (not shown) which can accommodate the first end of the auxiliary pull cable instead of the first upper clamping device.For example, depending on the design, it may be possible to use the control device to control one of the two drive units very quickly and the other very precisely, allowing both to be combined to advantage.

[0045] Furthermore, the drive unit can be connected to the movable mass in such a way that the movable mass is directly connected to a first end of the auxiliary traction cable, and the drive unit accommodates a second end of the auxiliary traction cable. This particularly compact design minimizes susceptibility to errors and maintenance effort.

[0046] The invention is explained in more detail below using schematic drawings. It shows: Figure 1 : a first view of the auxiliary drive, Figure 2 : a first detailed view of the auxiliary drive, Figure 3 : a second view of the auxiliary drive, Figure 4 : a first sectional view of the auxiliary drive, Figure 5 : a third view of the auxiliary drive, Figure 6 : a second detailed view of the auxiliary drive, Figure 7 : a fourth view of the auxiliary drive, Figure 8 : a fifth view of the auxiliary drive, Figure 9 : a third detailed view of the auxiliary drive and Figure 10 : a sixth view of the auxiliary drive.

[0047] Figure 1shows a first view of the auxiliary drive for the training device and a corresponding training device. The auxiliary drive for the training device comprises at least one first force-measuring device 1, at least one control device (not shown), and at least one drive unit 3. The control device determines a target force, FS,max , which should correspond to the maximum load of the trainee. This target force, FS,max , can be variable both over time and with regard to additionally determined variables; such a change can be continuous, essentially discrete, and in particular cyclical.The target force, FS,max , can be determined, for example, as a function of a direction of movement, a speed of movement, a change in the speed of movement, a biometric value of the trainee or a value of the trainee's cardiovascular system, or a combination thereof; a variety of physiological or biometric values ​​are conceivable that can be included in the calculation of the target force, FS,max . The first force measuring device 1 determines an actual force, FS , which is applied to a main traction means 11 of the training device, upon which the trainee acts, and which is essentially caused by an acceleration of a movable mass 5 connected to the main traction means. Such a main traction means 11 can, for example, be a rope or a belt, i.e. a machine element that is particularly suitable for transmitting a tensile force.This acceleration of the movable mass 5 includes both the constantly acting acceleration due to gravity or acceleration due to fall - that is to say the essentially constant acceleration due to gravity - and an additional dynamic acceleration brought about by the person training. The actual force, FS , determined on the main traction means 11 is transmitted from the first force measuring device 1 to the control device. The control device then compares the transmitted actual force, FS , with the target force, FS,max , and, if the actual force, FS , exceeds the target force, FS,max , the control device controls the drive unit 3 such that, by connecting the drive unit 3 to the movable mass 5, an auxiliary force, FZ , acts on the movable mass 5 which has a component counter to the acceleration due to gravity. In . Figure 2, a first detailed view of the auxiliary drive, the connection of the drive unit 3 with the movable mass 5 is shown as an example as a simple pulley, which is why the auxiliary force, FZ , is divided into two equal halves.

[0048] Since the control device only activates the drive unit 3 when the actual force, FS, measured on the main traction device 11, exceeds the target force, FS,max, the load on the trainee can never be greater than the load resulting from the movable mass 5 and the total acceleration acting on it. If the trainee does not apply a load that leads to an actual acceleration of the movable mass 5 against the acceleration due to gravity, the maximum acceleration of the movable mass 5 is the acceleration due to gravity. Therefore, if at least one component of the auxiliary force, FZ, acts against the acceleration due to gravity, it is ensured that the trainee can never unexpectedly experience a dangerously high load. This protection can also be further increased by intentionally limiting the auxiliary force absolutely or relative to the movable mass 5; for example, to a maximum of 150 N or 20% of the movable mass 5.Since the auxiliary force, FZ , can be limited in a fully functioning auxiliary drive for the training device, even assuming a complete system failure, the additional load cannot exceed the lost limited auxiliary force, FZ , and thus, for example, only amount to a maximum of 20% of the movable mass 5. In addition to increased safety, this also avoids increased power consumption. Since the person training can generally only apply a force that has a component counter to the acceleration due to gravity to the movable mass 5 via the main traction device 11, the auxiliary force, FZ , can only relieve the load on the person training, but never place an additional load on them. Only the unexpected absence of the auxiliary force, FZ , would result in a correspondingly unexpected load, which in turn would be caused solely by the well-defined movable mass 5 under the influence of the acceleration due to gravity.

[0049] The auxiliary drive for training equipment according to the invention thus has, as an essential safety feature, that, in particular, the maximum possible training resistance is well defined by the total movable mass 5. The design of the auxiliary drive for training equipment according to the invention offers the particular advantage that the maximum possible training resistance, well defined by the total movable mass 5, can be reached but never exceeded. To this end, the auxiliary drive according to the invention always acts on the total movable mass 5 only in such a way that the auxiliary force, FZ, acting on the movable mass 5 has at least one component counteracting the acceleration due to gravity, i.e., counteracting the acceleration due to gravity or the acceleration due to gravity.This ensures that the auxiliary force, FZ, can only reduce, but never increase, the force exerted by the trainee compared to the force acting solely on the movable mass 5 due to the acceleration of gravity. The auxiliary force, FZ, itself can be controlled with virtually any degree of fineness, which is why the trainee does not have to accept any discrete mass differences, for example, between individual weight plates.

[0050] Safely maintaining the maximum possible training resistance is also one of the main advantages of the present invention compared to active training equipment (fully electric strength training equipment), which can generate dynamic resistance purely electrically. Such equipment also requires a very high level of safety to prevent excessive strain or even potential injury in the event of a malfunction. In general, the costs of both purchasing and maintaining active training equipment (fully electric strength training equipment) are very high.

[0051] By means of the auxiliary drive according to the invention for the training device, the actual force to be exerted, and thus the load on the trainee, can be continuously adjusted during the execution of the exercise, while ensuring safe maintenance of the set maximum training resistance corresponding to the total movable mass 5. In the simplest case, a maximum load can be set with any finely graduated values, which can correspond at most to the mechanically predetermined maximum training resistance. Such a maximum load can also be adjusted during the execution of an exercise. A purely temporal adjustment or an adjustment based on a predetermined cycle, which can also take into account the trainee's cardiovascular values ​​or biometric values, is conceivable here.

[0052] As exemplified in Figure 1As shown, the auxiliary drive according to the invention can be designed as a conversion kit so that only additional elements are mounted on an existing strength training device, but no changes are required to the existing mechanics or covers or power-transmitting parts of the existing strength training device. Furthermore, no pull ropes or weight plates need to be dismantled, and no specialist personnel trained in electrical or electronic systems are required to commission the device and monitor it during normal operation.Due to the type of attachment and the basic functionality of the auxiliary drive according to the invention, as described above, the user cannot be subjected to mechanical stress greater than the adjustable maximum training resistance, the range of which is already predetermined by the manufacturer's weight plate configuration, with the acceleration due to gravity being considered essentially constant. This also avoids any product liability issues or remaining warranty claims.

[0053] Furthermore, such an auxiliary drive for the training device can advantageously provide an emergency braking function for the drive unit 3. In the event of a power failure or other malfunction, a hardware-implemented safety emergency stop function can be integrated, which then short-circuits the windings of an electric motor of the drive unit 3. This allows the movable mass 5 to be braked with the maximum torque of the electric motor in the event of a fault or disproportionately deviating measured values, for example, which exceed a limit value.

[0054] If, in the auxiliary drive, the control device compares the actual force, FS , transmitted to it with the target force, FS,max , and determines that the actual force, FS , exceeds the target force, FS,max , the control device advantageously controls the drive unit 3 in such a way that, by connecting the drive unit 3 to the movable mass 5, the auxiliary force, FZ , reduces the determined actual force, FS , applied to the main traction means 11. This makes it possible to verify, namely by the first force measuring device 1, that the actual force, FS , applied to the main traction means 11 has actually been reduced by the auxiliary force, FZ , thereby increasing safety.The auxiliary drive can therefore check whether the auxiliary force, FZ , actually reduces the actual force, FS , applied to the main traction means 11 or whether the applied auxiliary force, FZ , noticeably reduces the actual force, FS , applied to the main traction means 11.

[0055] If, in the case of the auxiliary drive, the control device compares the actual force, FS , transmitted to it with the target force, FS,max , and determines that the actual force, FS , exceeds the target force, FS,max , the control device advantageously controls the drive unit 3 in such a way that, by connecting the drive unit 3 to the movable mass 5, the auxiliary force, FZ , reduces the actual force, FS , applied and determined on the main traction means 11 essentially to the target force, FS,max . This can be verifiably guaranteed that the force to be applied by the trainee now essentially corresponds to the target force, FS,max , for example apart from existing friction losses or measurement inaccuracies. If the target force, FS,max , changes, the actual force, FS , also changes accordingly due to the control, since the auxiliary force, FZ , is constantly adjusted.While maintaining all the positive safety features described above, this allows for a nearly infinitely adjustable and optimizable workload for the trainee. It is also possible to capture system-inherent losses, such as friction losses, and adjust the control accordingly.

[0056] The auxiliary drive can advantageously additionally comprise a motion sensor 8 (not shown), which is configured to determine a direction of movement of the movable mass 5 and transmit it to the control device. The control device 2 can further be configured to determine the target force, FS,max , additionally as a function of the direction of movement of the movable mass 5. This can be used, for example, to generate an "eccentric overload," which can result in improved muscle development, since the load to be applied by the exerciser can be positively adapted to the current direction of movement.The muscles of the trainee can be loaded up to 30% higher in the eccentric contraction than in the concentric contraction, whereby the desired training stimulus on the muscles is achieved by means of a correspondingly adjusted target force, FS,max , and a correspondingly changed auxiliary force, FZ , and a correspondingly increased muscle growth is triggered.

[0057] Advantageously, the motion sensor 8 can be integrated directly into the drive unit, ensuring both a particularly space-saving design and special protection against possible external damage. Furthermore, the integrity of the measurement can be increased if the motion sensor 8 performs the measurement directly in the drive unit 3, thus eliminating the involvement of other machine elements that could distort the measurement, for example, because they are susceptible to vibration or have play.

[0058] Furthermore, the first force measuring device 1 of the auxiliary drive can be configured to determine a tension of the main traction device 11 in order to determine the actual force, FS . In principle, with a known tension, the applied actual force, FS , can be deduced very precisely, which also increases the precision of the control resulting from the comparison with the target force, FS,max . As described above, the control of the drive unit 3 by the control device is fundamentally based on the comparison of the actual force, FS , transmitted by the first force measuring device 1 with the target force, FS,max . Consequently, increased precision in determining the actual force, FS , also results in the possibility of more precise control of the drive unit 3.

[0059] Advantageously, the first force measuring device 1 can be configured so that the tension of the main traction means 11 is determined by means of a deflection; see also Figure 1This represents a particularly reliable method of determining the voltage and thus the actual force, FS , which in turn increases the reliability of the control of the drive unit 3 by the control device resulting from the comparison with the target force, FS,max . As exemplified in Figure 1 As shown, the first force-measuring device 1 can have a spring mechanism whose deflection increases the greater the tension present in the main tension member 11. Consequently, the actual force, FS, can be determined from the deflection of the spring mechanism.

[0060] Furthermore, the first force measuring device 1 can also be configured to determine the actual force, FS, by detecting an elongation of the main traction element 11. The actual force, FS, can also be very precisely deduced from an elongation.

[0061] Since in the linear-elastic range (proportional range, "Hooke's line") the strain is proportional to the stress and thus Hooke's law applies, both methods of determining the actual force, FS , can be carried out either alternatively or in parallel. If two measured values ​​of the actual force, FS , determined in different ways are available, they can be compared appropriately, thereby further increasing the integrity of the measurement. An assessment of the suitability of the measurement method with regard to the rate of change of the measured values ​​or the dynamics in general is also conceivable. The comparison of the values ​​of the actual force, FS , determined via stress and strain can therefore directly consider the respective values, but a weighting can also be applied (additionally) based on a change in the underlying values.

[0062] Advantageously, the first force-measuring device 1 can be a strain gauge (DMS) and / or comprise a magnetostrictive sensor operating according to the principle of magnetostriction. Both strain gauges and magnetostrictive sensors are available from common suppliers in a wide variety of designs, thus well-adapted to specific needs, which can also reduce costs. The measured values ​​can be compared directly or by taking their respective changes into account. In addition, strain gauges, in particular, are very space-saving and can be easily installed even in hard-to-reach locations.

[0063] Furthermore, the first force measuring device 1 can be configured to determine the actual force, FS , by comprising a weighing device (not shown) that can be configured to determine the mass of the movable mass 5 and by further comprising an acceleration sensor (not shown) that is configured to determine a second temporal change in a position of the movable mass 5. With knowledge of the accelerated mass, more precisely the accelerated movable mass 5, and knowledge of the corresponding acceleration, the actual force, FS , can be determined directly from Newton's second law by simply multiplying the two determined values.To do this, the weighing device must measure a difference between a weight force in the case where the movable mass 5 is resting only under the influence of gravitational acceleration and in the case where the movable mass is not resting, at a point where it can be detected that it is in contact. The advantage here is that the weighing device only has to determine the difference described above, and it is therefore irrelevant whether other masses are weighed at the same time. For example, it is also possible to attach the weighing device under a stack of mass plates comprising several mass plates, from which only, for example, the top two mass plates are then lifted. As already described above, several types of determination of the actual force, FS , can be carried out both alternatively to one another or in parallel.If two or more measured values ​​of the actual force, FS, are available, determined in different ways, they can be compared with each other, further increasing the integrity of the measurement. In general, the present invention considers it extremely advantageous if—very generally—determined variables are determined in different ways and / or multiple times; sensor data fusion can also be used for this purpose. As mentioned above, the dynamics of the underlying movement can be important in sensor data fusion, as can the dynamics of the change in the determined values.

[0064] Advantageously, the acceleration sensor can be a motion sensor configured to determine the absolute or relative position of the movable mass 5 and its first and second temporal derivatives, or a correspondingly proportional value thereto. It is conceivable that the motion sensor 8 described above is used in the configuration described here, or that an additional motion sensor is used, the data of which can then be used in addition to that of the existing motion sensor 8 and from which additional measured values ​​can also be determined, particularly after sensor data fusion.If the motion sensor 8 described above can determine the acceleration of the moving mass 5, it is sufficient for the first force measuring device 1 to include the weighing device described above in order to then determine the actual force, FS, applied to the main traction device 11 from the values ​​determined by the motion sensor 8 and the weighing device. Alternatively, the acceleration determined by the additional motion sensor can be compared with the acceleration determined by the motion sensor 8, thus improving the integrity of the measurement, for example.

[0065] Furthermore, in the auxiliary drive, the connection of the drive unit 3 to the movable mass 5 can act at a first point on the main traction means 11, which is closer to the movable mass 5 than a second point on the main traction means 11, at which the first force measuring device 1 determines the actual force, FS . This ensures that the actual force, FS , determined by the first force measuring device 1, which is applied to the main traction means 11 of the training device and is essentially applied by the user, cannot be distorted in the force flow within the main traction means 11. If the drive unit 3 acts at the first point on the main traction means 11 according to the invention, a particularly compact design of the auxiliary drive can also be achieved.

[0066] In addition, the drive unit 3 can comprise a generator (not shown), which makes it possible, particularly in the case of eccentric movement, not only to consume no energy, but even to recover energy, since the generator, for example, provides the required braking torque to generate the corresponding auxiliary force, FZ. Since the energy consumption of the drive unit 3 is reduced and additional energy is generated by the generator, any batteries / accumulators that may be present can be smaller and cheaper or can be used for longer. If no batteries / accumulators are present, the generator will in any case reduce power consumption and thus also costs; environmental protection is also promoted.

[0067] Advantageously, the auxiliary drive can additionally comprise a second force measuring device (not shown) configured to determine the auxiliary force, FZ, acting on the movable mass 5 and / or to determine the work effectively performed by the drive unit 3. This makes it possible to check the control of the drive unit 3, increase the precision of the control, and improve error detection. Vibration can also be better avoided in areas where the control could unintentionally cause vibration. Again, the second force measuring device can be integrated into the drive unit 3, which enables a compact, protected design, increases the integrity of the measurement, and furthermore enables comparatively simple force-displacement determination in order to determine the work effectively performed.The second force measuring device can also include a magnetostrictive sensor, similar to the first force measuring device. In addition to the effective work performed, the actual power generated by the drive unit 3 can also be determined. In principle, the corresponding quantities can also be determined additionally or alternatively by including a measured torque.

[0068] Furthermore, the auxiliary drive can additionally comprise an operating unit (not shown) which is configured to transmit data to the control device from which the control device can additionally determine the target force, FS,max . A variety of embodiments are conceivable here. In principle, the operating unit 4 can be configured to specify the target force, FS,max , and in particular also its profile or, as a rule, its change over time. For example, a number of different training programs can be selected from which the respectively valid target force, FS,max , is then determined. A comparatively simple control device can also be used here which, in addition to the profiles of the target force, FS,max , received from the operating unit, performs no or only a limited amount of further calculations to determine the target force, FS,max .A fundamentally modular design is therefore also conceivable, which can explicitly provide for redundancies, meaning different units can perform the same or similar calculations. This further increases the flexibility and range of applications of the auxiliary drive.

[0069] Furthermore, the control device can be additionally configured to transmit data to the control unit and / or to an IT infrastructure (not shown) and to receive data from the IT infrastructure. The control unit can further be configured to receive data from an external measuring unit (not shown) and / or data from the IT infrastructure and / or to transmit it to the IT infrastructure. This makes it possible, for example, to show the trainee how they can best follow or have followed target courses. Furthermore, results, for example the number of cycles or the work exerted by the trainee or current variables such as the current power output, can be transmitted to the control unit 4 in order to provide information and ensure verification of a selected goal.Furthermore, the data can also be transferred to the IT infrastructure, such as a computer or cloud, for analysis and evaluation. In particular, the trainee's development over time can be clearly displayed and monitored, and any necessary adjustments can be made. Advantageously, statically or dynamically determined parameters of the trainee can also be transmitted to the control unit via the control unit, either by input or by data forwarding, or the corresponding calculations can be performed in the control unit itself. In addition to the trainee's height, weight, age, and gender, other biometric values ​​or (current) cardiovascular values ​​that are suitable for determining an appropriate training plan are conceivable.The specifications for the ultimately generated target force curves, FS,max , can also originate from a (possibly second) IT infrastructure, such as a second computer or a second cloud. They can also be generated in the operating unit 4 itself or in the control device 2. The adjustment of the target force, FS,max , can also be continuous: for example, the IT infrastructure can receive the determined cardiovascular values ​​from the operating unit, together with the data that the control device transmits to the operating unit 4. The IT infrastructure can then, in turn, make a corresponding adjustment to the target force, FS,max , and transmit it to the control device via the operating unit. Restrictions to a single specific structure are therefore unnecessary.The fundamental redundancy for determining and specifying the target force, FS,max , can be considered particularly advantageous, since different units can be particularly suitable depending on the (current) data availability and computing power. A (wireless) network connection also makes it possible, in particular, for data and curves to be transmitted and analyzed without the need for an operator to be physically present at the auxiliary drive. It is also possible for a specific trainee to virtually automatically find a specifically tailored training program on various auxiliary drives according to the invention, and for their training results to be centrally recorded and evaluated.

[0070] Advantageously, the auxiliary drive may further comprise an auxiliary traction cable 12, which is connected both to the drive unit 3 and to the movable mass 5 indirectly, as in Figure 1 shown, or directly, as in Figure 10shown, and thus establishes the connection of the drive unit 3 with the movable mass 5. The Figure 10 The direct connection shown can be considered particularly simple and thus prone to failure. The auxiliary traction cable 12, along with a belt, may be particularly suitable for establishing a space-saving and secure connection between the drive unit 3 and the movable mass 5. A variety of customizable cables are designed and available as standard for a wide variety of requirements, thereby keeping their costs within limits. Furthermore, a hydraulic connection between the drive unit 3 and the movable mass 5 would also be conceivable, as would other mechanical connections—for example, by means of a gear, which may also include a slip clutch.

[0071] In addition, the drive unit 3 can be used as a cable drum, see Figure 1, which allows the auxiliary pull rope 12 to be wound up in a particularly space-saving and secure manner. This protects against potential damage and also prevents unwanted contact with other elements, such as the main traction device 11 – especially when a relatively long section of the auxiliary pull rope 12 has been wound up. This also minimizes the potential risk of injury to the trainee or other persons. Furthermore, the cable drum can be equipped with an anti-pinch device (not shown).

[0072] Particularly advantageously, the drive unit 3 can also be configured to always provide sufficient torque to wind up the auxiliary traction cable 12, whereby safety can be further increased since, due to the tension prevailing in the auxiliary traction cable 12, the probability of contact with other elements can be minimized and, furthermore, the response behavior can be further improved, in particular due to the lack of play.

[0073] The invention also relates to a system that can comprise the training device and the auxiliary drive for the training device with the features described above, wherein the movable mass 5 comprises one or more weight plates connected by means of a drive bar 6a and a pin 6b and movable in two substantially parallel guide rods 7a and 7b, wherein the connection of the movable mass 5 to the main traction means 12 is established via the drive bar 6a. This allows the total movable mass 5 to be defined particularly easily and reliably, and also ensures its safe guidance.Since the driving blade 6a generally rests on the uppermost mass plate with a wider area than the diameter of a cross-section of the driving blade 6a guided in the mass plate, the driving blade 6a together with the plug pin 6b ensures that the movable mass 5 is held together, even if it comprises several weight plates or mass plates.

[0074] Figure 3 shows a second view of the auxiliary drive. Advantageously, see Figures 1 to 3, the auxiliary drive of the system can additionally comprise two outer deflection pulleys 19a and 19b and two rear deflection pulleys 20a and 20b, which are connected to the movable mass 5 by a first and a second connecting device 13a and 13b, furthermore a first upper clamping device 10a, which is frictionally attached to one of the two parallel guide rods 7a and a second upper clamping device 10b, which is frictionally attached to the other of the two parallel guide rods 7b, wherein the first upper clamping device 10a can receive a first end of the auxiliary traction cable 12, the auxiliary traction cable 12 can be guided through the two outer deflection pulleys 19a and 19b and through the two rear deflection pulleys 20a and 20b, and the drive unit 3 can receive a second end of the auxiliary traction cable 12.As a result, the system can be designed such that the drive unit 3, by means of the auxiliary force, FZ, acts on the movable mass 5 in such a way that the latter is guided parallel to the two parallel guide rods 7a and 7b, without generating a resulting and thus braking moment. This reduces friction, thus the resistance and also the wear, and thus enables increased precision in the controlled load on the trainee. This is shown in . Figure 4 a first sectional view of the auxiliary drive along the line KK of the Figure 3 . As in Figure 4As shown, in order to prevent the undesirable moment, essentially vertical sections of the main traction means 11, the auxiliary traction cable 12 and both center axes of the two parallel guide rods 7a and 7b lie essentially in one plane. According to the invention, in the case of the simple pulley block shown, the drive unit 3 only has to apply half of the total auxiliary force, FZ, acting on the movable mass 5, which is why it can also be more compact. Of course, the correspondingly determined or predetermined sizes must be adapted. In addition to the drive unit 3 described above, which receives the second end of the auxiliary traction cable 12, the auxiliary drive can further comprise a second drive unit (not shown) which receives the first end of the auxiliary traction cable 12 instead of the first upper clamping device 10a.For example, depending on the design, it may be possible to use the control device to control one of the two drive units very quickly and the other very precisely, allowing both to be combined to advantage.

[0075] As in Figure 2As shown, the second connecting device 13b can be designed as a second lower clamping device with a second sliding bushing 14b, which in turn is firmly connected to the movable mass 5; in the area of ​​the first guide rod 7a, the auxiliary drive accordingly comprises a first connecting device 13a, which can be designed as a first lower clamping device with a first sliding bushing 14a, which in turn is firmly connected to the movable mass 5. One or more screw connections can be provided for fastening the two lower clamping devices as well as the two upper clamping devices 10a and 10b. The clamping devices can be designed in one or more parts. A two-part embodiment with two screw connections each allows for particularly simple assembly on both the sliding bushings 14a and 14b (see Figure 4) as well as on the two parallel guide rods 7a and 7b. The (partial) loosening of one of the screw connections is generally suitable for setting both a rotational and a translational degree of freedom. Thus, fine adjustment can be performed very quickly. The two outer deflection pulleys 19a and 19b and the two rear deflection pulleys 20a and 20b each deflect the auxiliary traction cable 12 essentially by 90°.

[0076] In Figure 5 and Figure 6It is shown that the first and second connecting devices 13a and 13b can also be connected to one another via a third connecting device 13c each. The connection of all of the aforementioned connecting devices to the movable mass 5 is in turn effected by means of a securing bolt 6c in each of the two third connecting devices 13c. Because the two lower clamping devices can be dispensed with here, no negative influence can be exerted on the sliding bushings 14a and 14b, which could potentially result in increased friction between the sliding bushings 14a and 14b and the two parallel guide rods 7a and 7b.

[0077] In Figure 7 to Figure 9It is shown that, alternatively, the first and second connecting devices 13a and 13b can also be connected directly to the uppermost mass plate and thus to the movable mass 5 by means of a first and a second fastening strap 9a and 9b. Particularly advantageously, a center line of the respective fastening strap 9a or 9b and the corresponding vertical section of the auxiliary traction cable 12 are each located essentially in one plane. This prevents a torque acting on the first or second connecting devices 13a and 13b from being generated via the two outer deflection pulleys 19a and 19b. Advantageously, the first and second fastening straps 9a and 9b can each be tensioned via a first and a second tensioning device 15a and 15b. This enables rapid, tool-free assembly of the first and second connecting devices 13a and 13b to the uppermost mass plate.

[0078] As in Figure 10 Furthermore, as shown, the connection of the drive unit 3 to the movable mass 5 can be made such that the movable mass 5 is directly connected to a first end of the auxiliary traction cable 12 and the drive unit 3 accommodates a second end of the auxiliary traction cable 12. This particularly compact design minimizes the susceptibility to errors and maintenance effort. Furthermore, the cable length of the auxiliary traction cable 12 can be approximately halved if the lifting height of the movable mass 5 is assumed to be the same, since the simple pulley block is omitted. If a lower torque of the drive unit 3 is desired or required, a multiple pulley block (not shown) can of course also be used to establish the connection between the drive unit 3 and the movable mass 5.

[0079] The individual features of the invention are of course not limited to the described combinations of features within the scope of the presented embodiments and can also be used in other combinations depending on predetermined parameters. 1: first force measuring device 3: drive unit 5: movable mass 6a: driving blade 6b: plug-in pin 6c: securing bolt 7a, 7b: guide rod 8: motion sensor 9a, 9b: fastening belt 10a, 10b: upper clamping device 11: main traction device 12: auxiliary traction cable 13a, 13b, 13c: connecting device 14a, 14b: sliding bushing 15a, 15b: tensioning device 19a, 19b: outer deflection pulley 20a, 20b: rear deflection pulley

Claims

1. Auxiliary drive for a training machine, which comprises a first force measuring device (1), a control device (2) and a drive unit (3), characterized in that the control device (2) is configured to determine a setpoint force (FS,max), the first force measuring device (1) is configured to determine an actual force (FS) which is applied to a main traction means (11) and which is substantially caused by an acceleration of a movable mass (5) which is connected to the main traction means (11), and wherein the first force measuring device (1) is further configured to transmit the determined actual force (FS) to the control device (2), the control device (2) is further configured to compare the actual force (FS) with the setpoint force (FS,max) and to control the drive unit (3) in such a way that, if the actual force (FS) exceeds the setpoint force (FS,max), an auxiliary force (FZ) which has a component counter to an acceleration due to gravity acts on the movable mass (5) as a result of a connection of the drive unit (3) to the movable mass (5).

2. Auxiliary drive according to Claim 1, wherein the control device (2) is further configured to control the drive unit (3) in such a way that, if the actual force (FS) exceeds the setpoint force (FS,max), the auxiliary force (FZ) reduces the actual force (FS) which is applied to the main traction means (11) and is determined, and preferably reduces the actual force (FS) which is applied to the main traction means (11) and is determined substantially to the setpoint force (FS,max).

3. Auxiliary drive according to at least one of Claims 1 and 2, wherein the auxiliary drive additionally comprises a movement sensor (8) which is configured to determine a movement direction of the movable mass (5) and to transmit it to the control device (2), and the control device (2) is further configured to determine the setpoint force (FS,max) additionally as a function of the movement direction of the movable mass (5), and wherein preferably the movement sensor (8) is configured to determine an absolute or relative position of the movable mass (5) and / or the first and / or second time derivative thereof, or in each case a variable which is correspondingly proportional thereto, and to transmit it to the control device (2), and the control device (2) is further configured to determine the setpoint force (FS,max) additionally as a function of the position of the movable mass (5) and / or the first and / or second time derivative thereof, and wherein particularly preferably the movement sensor (8) is integrated into the drive unit (3).

4. Auxiliary drive according to at least one of Claims 1 to 3, wherein the first force measuring device (1) is configured to determine a tension of the main traction means (11) in order to determine the actual force (FS), and preferably the first force measuring device (1) is configured to determine the tension of the main traction means (11) by means of a deflection, and / or preferably wherein the first force measuring device (1) is configured to determine an elongation of the main traction means (11) in order to determine the actual force (FS), and particularly preferably the first force measuring device (1) is a strain gauge and / or comprises a magnetostrictive sensor.

5. Auxiliary drive according to at least one of Claims 1 to 4, wherein the first force measuring device (1) is configured to determine the actual force (FS) in that it comprises a weighing apparatus which is configured to determine the mass of the movable mass (5) and in that it further comprises an acceleration sensor which is configured to determine a second change in time of a position of the movable mass (5), and wherein preferably the acceleration sensor is a movement sensor (8) which is configured to determine the absolute or relative position of the movable mass (5) and the first and second time derivative thereof or in each case a variable which is correspondingly proportional thereto.

6. Auxiliary drive according to at least one of Claims 1 to 5, wherein the connection of the drive unit (3) to the movable mass (5) acts at a first point of the main traction means (11) which is located closer to the movable mass (5) than a second point of the main traction means (11) at which the first force measuring device (1) determines the actual force (FS).

7. Auxiliary drive according to at least one of Claims 1 to 6, wherein the drive unit (3) comprises a generator.

8. Auxiliary drive according to at least one of Claims 1 to 7, wherein the auxiliary drive additionally comprises a second force measuring device which is configured to determine the auxiliary force (FZ) which acts on the movable mass (5).

9. Auxiliary drive according to at least one of Claims 1 to 8, wherein the auxiliary drive additionally comprises an operator control unit (4), and the operator control unit (4) is configured to transmit data to the control device (2), from which data the control device (2) additionally determines the setpoint force (FS,max), and wherein preferably the control device (2) is further configured to transmit data to the operator control unit (4) and / or to an IT infrastructure and to receive data from the IT infrastructure, and the operator control unit (4) is further configured to receive data from an external measuring unit and / or from the IT infrastructure and / or to transmit it to the IT infrastructure.

10. Auxiliary drive according to at least one of Claims 1 to 9, wherein the auxiliary drive additionally comprises an auxiliary traction cable (12) which is connected to the drive unit (3) and the movable mass (5) and thus establishes the connection of the drive unit (3) to the movable mass (5).

11. Auxiliary drive according to Claim 10, wherein the drive unit (3) is designed as a cable drum.

12. Auxiliary drive according to Claim 11, wherein the drive unit (3) is configured to always provide a sufficient torque to wind up the auxiliary traction cable (12).

13. System, comprising the training machine and the auxiliary drive for the training machine according to at least one of Claims 10 to 12, wherein the movable mass (5) comprises one or more weight plates which are connected by means of a carrying blade (6a) and a plug-in pin (6b) and are movable in two parallel guide rods (7a, 7b), and the connection of the movable mass (5) to the main traction means (11) takes place via the carrying blade (6a).

14. System according to Claim 13, wherein the auxiliary drive additionally comprises two outer deflection rollers (19a, 19b) and two rear deflection rollers (20a, 20b) which are connected to the movable mass (5) by a first and a second connecting device (13a, 13b), a first upper clamping device (10a) which is attached in a force-fitting manner to one of the two parallel guide rods (7a, 7b) and a second upper clamping device (10b) which is attached in a force-fitting manner to the other of the two parallel guide rods (7a, 7b), wherein, the first upper clamping device (10a) receives a first end of the auxiliary traction cable (12), the auxiliary traction cable (12) is guided by the two outer deflection rollers (19a, 19b) and by the two rear deflection rollers (20a, 20b), and the drive unit (3) receives a second end of the auxiliary traction cable (12).

15. System according to Claim 13, wherein the connection of the drive unit (3) to the movable mass (5) takes place by the movable mass (5) being connected to a first end of the auxiliary traction cable (12) and the drive unit (3) receiving a second end of the auxiliary traction cable (12).