Method and ergometer brake for force-dependent dynamic alteration of the braking force of an exercise apparatus

Abstract

The invention relates to a method for force-dependent dynamic alteration of the braking force of an exercise apparatus, in which method a brake system is made available consisting of a flywheel and of a plurality of permanent magnets able to move axially or radially with respect to the flywheel, wherein the permanent magnets are non-positively coupled to a force-transmitting device, and the magnetic field generated by the permanent magnets and acting on the flywheel is dependent on the force applied to the force-transmitting device, such that the magnetic field acting on the flywheel becomes greater as the force acting on the force-transmitting device increases. The invention further relates to an ergometer brake which permits a force-dependent dynamic alteration of the braking force of an exercise apparatus, in particular of a rowing ergometer. Finally, the invention relates to an exercise apparatus equipped with such an ergometer brake.

Description

[0001] Method and ergometer brake for force-dependent dynamic change of the braking force of a training device

[0002] Description:

[0003] Technical area:

[0004] The present invention relates to a method for force-dependent dynamic variation of the braking force of a training device. The invention further relates to an ergometer brake that enables force-dependent dynamic variation of the braking force of a training device, in particular a rowing ergometer. Finally, the invention relates to a training device equipped with such an ergometer brake.

[0005] State of the art:

[0006] Modern ergometers are equipped with braking systems to adjust the resistance, which must meet different requirements depending on the type of training device. The braking system ensures that the exerciser's training intensity can be adjusted. Increasing the training intensity is usually achieved by slowing down a flywheel using a braking system, usually a magnet, which makes it more difficult for the exerciser to move the flywheel. The user usually specifies the force required for the workout.

[0007] There are three main types of braking systems used in modern ergometers: magnetic brakes, induction brakes, and air resistance brakes. With a magnetic brake, a metal flywheel is braked by the magnetic force of a permanent magnet, the distance between which can be mechanically adjusted using an electronically controlled servomotor. By increasing the wattage or resistance values, the permanent magnet is moved by the motor towards the flywheel. This strengthens the effect of the magnetic field and brakes the flywheel. Magnetic braking systems ensure that there is no material wear, as the flywheel is not touched during braking. The flywheel is also moved in a controlled manner at a constant speed, thus preventing unwanted movement. The disadvantage, however, is that such braking systems only allow for consistent or static resistance, as the exerciser has to apply the force required for training, e.g.For example, the pedal resistance can be adjusted to suit your needs. Even training programs that offer a predefined intensity profile or performance-controlled programs are ultimately static, as the resistance only changes intermittently.

[0008] The induction brake, also known as an eddy-current brake, operates wear-free. The magnetic field is generated not by a moving permanent magnet, but by an electric coil and a current flow. With this braking system, the strength of the magnetic field is not regulated by the distance between the magnet and the flywheel, but by the strength of the coil's current flow. This allows for more precise load control. One advantage of the induction brake is that the braking force increases with increasing speed. The flywheel can therefore be decelerated more quickly at high speeds. This enables high-intensity interval training, as higher resistance values ​​can be achieved.

[0009] The aim of such training devices and the braking systems equipped with them is always to simulate the sport in question as naturally. Unfortunately, the systems mentioned above reach their limits here, as dynamically changing resistances or forces cannot be simulated, or only inadequately. For example, a key component in cycling is wind resistance, and on a mountain ride, the gradient of the route. Both components must be simulated by an ergometer brake, i.e. a variable basic resistance in relation to the gradient and a resistance that builds up over the riding speed in relation to the headwind. The induction brakes frequently used in ergometers are highly accurate, but unlike real cycling, they are accompanied by a time delay, which contributes to an unrealistic riding impression for the trainee.Sports that involve water resistance, such as swimming, rowing, or canoeing, also experience the specific properties of physical resistance. The fluidity of the water depends on the size, shape, and speed of the rower's blade or the swimmer's hand. While there are air resistance brakes that address this problem, they rely on an airflow induced by muscle power. A fan impeller is driven by the exerciser's muscle power, inducing an airflow that creates a braking dynamic pressure in the housing. The dynamic pressure increases the greater the difference in speed between the existing airflow and the airflow induced by the muscle power. Such a brake is used, for example, on rowing, swimming, canoeing, or cycling ergometers.Despite the relatively good imitation of fluid resistance, training systems equipped with such braking systems struggle with very high noise emissions, which are caused, in part, by the high sound pressure generated. Therefore, when several of these devices are used in one room, athletes often have to wear hearing protection to block out the noise from these ergometers. This is unsatisfactory. Various braking systems for ergometers are also part of the patent literature. WO 2016 / 009213 A1 describes a water brake for a rowing ergometer that is intended to provide an ideal resistance level for the user.

[0010] CH 712467 A2 describes a rowing simulation device which has a guided weight by means of a carriage and a guide on a swivel arm with an active cylinder, which is controlled by a controller.

[0011] DE 10 2008 028377 A1 describes an ergometer in which the braking force acting on the flywheel is switched with each revolution depending on the angular position of the pedals. The ergometer comprises a drive unit to which the two pedals are rigidly attached. Preferably, the angular position of the pedals is detected by a sensor system, and the switching of the braking force occurs purely electronically or electrically.

[0012] US Patent No. 4,798,378 A describes a rowing training device with a flywheel that is braked by an eddy-current brake. The power supply to the solenoid coil is closed or opened at the position corresponding to the rowing stroke, thus providing a typical rowing resistance behavior.

[0013] US Pat. No. 3,528,653 A utilizes the effect of frictional forces to create resistance. The training device, with its cantilevered design, is decelerated by the force exerted by the brake shoes on the shaft connected to the belt or sculls. The resistance must be adjusted individually for each belt or scull.

[0014] Description of the invention:

[0015] Against this background, it is the object of the present invention to provide an ergometer brake and a method with which a force-dependent dynamic change of the braking force of a training device is made possible that is as close to reality as possible, in order to imitate, for example, a fluidic resistance.

[0016] This object is achieved by a method having the features of claim 1, an ergometer brake having the features of claim 5 and a training device equipped with such an ergometer brake according to claim 14. Preferred embodiments can be found in the subclaims. The ergometer brake according to the invention has the task of operating as quietly as possible in order to prevent or at least significantly reduce the high noise emissions associated with air brakes. At the same time, the dynamic force changes that occur in reality are to be reflected in a training device by the braking system according to the invention. The ergometer brake according to the invention is therefore intended to be able to represent fluid-dynamic resistance as well as acceleration-dependent braking forces. At the same time, a basic force or starting force is intended to remain variably adjustable. Dynamic resistance requires a resistance that reacts to acceleration.The acceleration is proportional to the resistance force.

[0017] The ergometer brake according to the invention comprises a flywheel and a plurality of permanent magnets movable axially or radially relative to the flywheel. The permanent magnets are frictionally coupled to a force transmission device. A lever ensures that, for example, when a tensile force is applied, the permanent magnets and the magnetic field generated thereby are moved toward the flywheel. For this purpose, the lever is coupled to the permanent magnets at one end. The lever is returned to its initial state by at least one spring coupled to the other end of the lever. According to the invention, the magnetic field generated by the permanent magnets and acting on the flywheel is dependent on the force acting on the force transmission device, so that when the force acting on the force transmission device increases, the magnetic field acting on the flywheel increases.The position of the permanent magnets relative to the flywheel is thus directly dependent on the applied force, which leads to an adjustment of the lever. According to the invention, the lever is adjusted via a tension element, preferably a tension cable, a chain, or a belt. In a preferred variant, the tension element is guided over deflection pulleys. This enables improved power transmission while simultaneously achieving a more compact design. In a further preferred embodiment, the tension element is guided in an S-shape over the deflection pulleys.

[0018] According to the invention, "basic resistance" refers to the generation of a constant resistance. This resistance is preferably variably adjustable, as with other training devices.

[0019] According to the invention, "dynamic resistance" refers to a resistance that reacts to acceleration. The acceleration is proportional to the resistance force. According to the invention, "freewheel" refers to a resistance value of 0, i.e., the strength of the base resistance and the dynamic resistance have the value 0.

[0020] The braking system according to the invention enables the generation of dynamic resistance depending on the acceleration generated by the exerciser by increasing (or decreasing) their force input. During freewheeling, i.e., when the applied force decreases, the permanent magnets or the magnetic field are released from the flywheel, so that it experiences no braking, neither by the dynamic braking effect nor by the basic resistance. At the same time, the system is reset to its initial state. If the system is reset to its initial state, this is usually a partial function of the resistance-free state.

[0021] The ergometer brake according to the invention and the method underlying it represent a braking cycle. After the brake has returned to its original state, the system can be restarted.

[0022] The ergometer brake according to the invention and the method for simulating fluidic resistance are based on a combination of a lever effect, a connected spring force, and the braking effect on a spring disc triggered by a magnetic field. The depth or strength of the lever deflection is determined by the pulling force of the exerciser. The more intensively the lever acts on the disc, the greater the resulting resistance force. When the user-specific pulling force decreases, the lever is released from the flywheel due to the acting spring force, allowing the disc to rotate freely without resistance.The key to the dynamic braking force variation of the training device is that when the force acting on the power transmission device increases, the permanent magnets are moved toward the flywheel, while when the force acting on the power transmission device decreases, the permanent magnets are moved away from the flywheel. The design and layout of the lever of the power transmission device depends on the positioning of the pivot point in conjunction with the size of the flywheel and the arrangement of the pulleys.

[0023] Preferably, the two pulleys of the power transmission device are positioned at the same distance from the pivot point. The lever is coupled either directly or indirectly to at least one spring, preferably two springs. The spring force is preferably selectable or adjustable. The two ends of the lever essentially define two different functional areas, namely an immersion area and a stabilization area. The stabilization area serves to fix the cable pulleys or the lever to the device, while the immersion area ensures that the permanent magnets move either axially or radially toward the flywheel.

[0024] To ensure the return function of the tension element, an elastic tension element is preferably used, for example a rubber cord. Deflecting the tension element over several pulleys saves space without having to shorten the elastic tension element, which is dependent on extension. The force required for maximum extension of the elastic tension element is determined by measuring the return force of the tension element in training equipment with a fluid-dynamic resistance. The lever size of the power transmission device lever is selected according to requirements but depends on the immersion depth of the magnetic field in the flywheel. The magnetic field, in turn, depends, among other things, on the number, size and arrangement of the permanent magnets used. The part of the lever coupled to the permanent magnets preferably comprises a receiving element for attaching the permanent magnets.

[0025] The spring force required for the return function depends on the tensile force exerted by the tension element, the strength of the tension element's return force, and the spring travel. The spring travel is determined by the depth of penetration of the magnetic field or the lever equipped with the permanent magnet into the flywheel. Only the braking torque generated by the magnetic field counteracts the tensile torque. The braking torque depends on the number of permanent magnets used, the distance of the excitation magnet from the pivot point, and the braking force of each individual excitation magnet.

[0026] In a preferred variant, the flywheel is made of aluminum, as this material, in addition to providing the required stability, also exhibits excellent electrical conductivity properties. The use of aluminum enables high efficiency when the braking system is designed as an eddy-current brake.

[0027] The invention also relates to a training device equipped with an ergometer brake described here. Preferably, the training device is a rowing ergometer. However, the ergometer brake according to the invention can be used in swimming ergometers, canoe ergometers, and bicycle ergometers.

[0028] The ergometer brake according to the invention has the advantage that the braking force can be dynamically varied. In known systems, the relationship between the magnetic field and the flywheel is usually statically varied by a mechanism used to adjust the braking force. It is irrelevant whether the braking effect can be adjusted by a radial or axial change in the distance between the magnet and the flywheel, and whether this adjustment mechanism is carried out mechanically by the lever or by actuators, by pneumatic or hydraulic elements, or by an electric motor. The ergometer brake according to the invention is characterized by a flywheel set in rotation by the movement of the exerciser, which is braked by an axially or radially approximated magnetic field in relation to the applied muscle power and the resulting torque or tensile force.The pulling force generated by the user or the torque developed in the training device is mechanically transferred to the position of the permanent magnets and thus to the orientation and intensity of the magnetic field. This dynamically changes the position of the magnetic field in relation to the flywheel.

[0029] In a preferred embodiment, the tensile force or torque generated by the exerciser is detected by sensors. The magnetic field is preferably brought closer by an electric, hydraulic, or pneumatic actuator.

[0030] Thanks to the frictionless braking system, the ergometer brake according to the invention operates largely silently. Compared to rowing ergometers equipped with an air brake, the ergometer brake according to the invention was measured to be over 20 dB lower. This noise level can be further reduced by additional dampening measures in the housing or housing panels. The measurements were taken at a distance of one meter from the respective ergometer.

[0031] The invention is explained in more detail in the following drawings. These are exemplary embodiments intended to illustrate the inventive method for force-dependent dynamic variation of the braking force of a training device and an ergometer brake designed for this purpose. The invention is in no way intended to be limited to the described embodiments. The present invention also encompasses the combination of individual or multiple features of different embodiments. For example, it will be clear to those skilled in the art that induction-controlled magnets or a combination of a magnetic brake and an induction brake can be used instead of permanent magnets.

[0032] Short description of the drawings:

[0033] Fig. 1 shows the basic principle of the ergometer brake according to the invention; Fig. 2 shows a rowing ergometer equipped with an ergometer brake according to the invention;

[0034] Fig. 3 shows the tensile force curve of a training device which is equipped with an ergometer brake according to the invention.

[0035] Ways of implementing the invention and industrial applicability:

[0036] Fig. 1 shows the basic principle of the ergometer brake according to the invention. The basic components of the ergometer brake are a flywheel 22 and permanent magnets 20, which are arranged at the lower end of a lever 16. The upper end of the lever 16 is force-lockingly coupled to at least one spring 11. When a pulling force is applied, the flywheel 22 is set into a rotational movement via a pulling element 10 (e.g., rope, belt, or chain). The pulling element 10 is guided in an S-shape via deflection pulleys 12, 14. The upper deflection pulley 12 and the lower deflection pulley 14 are arranged at the same distance from a central pivot point 13. The lower part of the lever 16 with the permanent magnets 20 is moved towards the flywheel 22 when a user-specific pulling force is applied. The distance covered and thus the resulting magnetic field depend on the applied pulling force.If the pulling force decreases, as is the case, for example, when rowing, when the oar is to be simulated sliding out of the water, the lever is moved away from the flywheel 22, allowing the flywheel 22 to rotate freely. At this point, the system experiences no braking effect.

[0037] The two pulleys 12, 14 are located on the lever 16, which is connected to the spring 11 at its upper, shorter end. The lower, longer part of the lever 16 contains the braking element (permanent magnets) for braking the attached flywheel. The use of the permanent magnets 20 enables speed-dependent braking. Due to the resulting cable friction and bearing friction of the pulleys 12, 14, as well as the interplay of spring force and the return force of the pulling element 10, the described lower part of the lever 16 is guided towards the flywheel 22 when the pulling element 10 is pulled. The depth of immersion of the lever 16 is determined by the pulling force of the exerciser. The closer the lever 16 is guided to the flywheel 22, the greater the magnetic field and thus the resulting braking force.When the user-specific pulling force decreases, the lever 16 is released from the flywheel 22 due to the acting spring force, allowing the disc to rotate freely without resistance. Fig. 2 shows a rowing ergometer equipped with the ergometer brake according to the invention. The figure on the left shows the zero position, i.e. the position in which no pulling force is exerted on the pulling element 10. Depending on the applied pulling force, the spring 11 expands and pivots the magnetic field created by the permanent magnets 20 on the lever 16 to varying depths into the flywheel 22. This occurs either radially or axially, depending on the application. After the pull-dependent force maximum is reached, the resistance force decreases. The spring then returns to its original state, thereby withdrawing the magnetic field from the flywheel 22.This allows the flywheel 22 to continue rotating unhindered, which, for example, corresponds to the gliding of a rowing boat. In the illustrated design, the lever 16 dips into the flywheel to approximately half its width at a tensile force of 400 N. In the illustrated version, six permanent magnets are used as excitation magnets (type S-15-08-N; magnetic flux density 0.535 T). The resistance behavior is thus very similar to that of real rowing.

[0038] One advantage of the system according to the invention is that no additional energy source is required to generate the braking force. Compared to air brakes, the system according to the invention is considerably quieter, so the trainee does not need to take any soundproofing measures such as headphones, etc.

[0039] Fig. 3 shows the force curve of a training device equipped with an ergometer brake according to the invention compared to a conventional rowing ergometer. The measurement delivers results that correspond to the required behavior. The force value increases rapidly, reaches an individual maximum, and then drops to zero, as is typical for rowing. The data show that the deficiencies of conventional rowing ergometers can be eliminated by achieving a dynamically changing effective resistance of the brake. The braking system according to the invention operates quietly and requires no power, and its resistance behavior resembles a rower's stroke. The ergometer brake according to the invention is therefore suitable for implementing quiet, powerless, fluid-dynamic resistance.

[0040] In summary, the ergometer brake according to the invention enables the speed and the field of action of the magnetic force on the flywheel to be increased as the traction force increases, which triggers a higher braking torque.

Claims

Patent claims:

1. Method for force-dependent dynamic modification of the braking force of a training device, in which a braking system is provided, consisting of a flywheel and a plurality of permanent magnets movable axially or radially to the flywheel, wherein the permanent magnets are force-fit coupled to a force transmission device, characterized in that the magnetic field generated by the permanent magnets and acting on the flywheel is dependent on the force applied to the force transmission device, such that when the force acting on the force transmission device is increased, the magnetic field acting on the flywheel increases.

2. Method according to claim 1, characterized in that when the force acting on the power transmission device increases, the permanent magnets are moved towards the flywheel and when the force acting on the power transmission device decreases, the permanent magnets are moved away from the flywheel.

3. Method according to claim 1 or claim 2, characterized in that the power transmission device comprises a lever which is coupled at one end to at least one spring and at the other end to the permanent magnets, wherein the part of the lever coupled to the permanent magnets is moved towards the flywheel depending on a user-specific pulling force, while when the user-specific pulling force decreases, the lever is released from the flywheel due to the acting spring force and allows the flywheel to freewheel.

4. Method according to claim 3, characterized in that the force-dependent movement of the permanent magnets via the lever is effected by a pulling element which is guided in an S-shape over at least two deflection pulleys which are arranged at the same distance from the pivot point, wherein the pulling element is preferably a pull rope, a chain or a belt.

5. Ergometer brake for force-dependent dynamic change of the braking force of a training device, comprising a flywheel (22) and a plurality of permanent magnets (16) movable axially or radially to the flywheel (22), wherein the permanent magnets (16) are frictionally coupled to a force transmission device comprising a lever (16) which is connected at one end to at least one spring (11) is coupled and at the other end to the permanent magnets (20), wherein the magnetic field generated by the permanent magnets (20) and acting on the flywheel (22) depends on the force applied to the power transmission device, so that when the force acting on the power transmission device is increased, the magnetic field acting on the flywheel (22) increases.An ergometer brake according to claim 5, characterized in that the lever (16) of the force transmission device is coupled at one end to the at least one spring (11) and at the other end to the permanent magnets (20), wherein the part of the lever (16) coupled to the permanent magnets (20) is movable towards the flywheel (22) depending on a user-specific pulling force, while when the user-specific pulling force decreases, the lever (16) moves away from the flywheel (22) due to the acting spring force and allows the flywheel (22) to freewheel. An ergometer brake according to claim 6, characterized in that the force-dependent movement of the permanent magnets (20) via the lever (16) is effected by a pulling element (10) which is guided in an S-shape over at least two deflection pulleys (12, 14), wherein the at least two deflection pulleys (12, 14) are arranged at the same distance from a pivot point (13).Ergometer brake according to claim 7, characterized in that the pulling element (10) is a pull rope, a chain, or a belt. Ergometer brake according to claim 6, characterized in that the lever length of the lever (16) depends on the immersion depth of the magnetic field into the flywheel (22). Ergometer brake according to claim 6, characterized in that the part of the lever (16) coupled to the permanent magnets (20) comprises a receiving element for attaching the permanent magnets (20). Ergometer brake according to any one of claims 5 to 10, characterized in that the spring force of the at least one spring (11) is adjustable depending on the tensile force emanating from the pulling element (10), the strength of the return force of the pulling element (10), and the spring travel, wherein the spring travel is determined by the immersion depth of the magnetic field. Magnetic field in the flywheel (22). Ergometer brake according to one of claims 5 to 11, characterized in that a braking torque is generated which counteracts the pulling torque, wherein the braking torque depends on the number of permanent magnets (20) used, the distance of the excitation magnet to the pivot point (13) and the braking force of each individual excitation magnet. Ergometer brake according to one of claims 5 to 13, characterized in that the flywheel (22) is made of aluminum. Training device equipped with an ergometer brake according to one of claims 5 to 11.

13. Training device according to claim 14, characterized in that the training device is a rowing ergometer.

Images