Hybrid resistance generation system for fitness equipment

Abstract

The present application relates to a hybrid resistance generation system for fitness equipment, the system comprising a set of counterweights providing a first source of resistance and an electromechanical resistance module providing a second source of resistance, the two sources of resistance being connected in series by a counterweight lever such that the resultant total resistance acts on a first cable operably connected to a user interface, the electromechanical resistance module includes an electric motor with a winch for winding and unwinding a second cable that is removably connected to the counterweight lever by a tool-free adapter.

Description

TECHNICAL FIELD

[0001] The present application relates to a hybrid resistance generation system for a fitness machine. The hybrid resistance generation system comprises a stack of weights having a plurality of weights connectable with a weight bar providing a first resistance source, and an electromechanical resistance module providing a second resistance source. The first resistance source and the second resistance source are connected in series, such that a resultant resistance source acts on a first cable connected with the weight bar. BACKGROUND

[0002] Generally, a fitness machine is a mechanical device designed to support and optimize physical exercise. These machines are commonly used in gyms, rehabilitation centers, and also in private homes to train various muscle groups, improve physical fitness, and achieve specific health goals. Fitness machines come in different types, such as aerobic machines to enhance cardiovascular health, strength machines to increase muscle strength and muscle mass, and flexibility and stretching machines to improve body flexibility and range of motion. Multi-functional machines combine multiple functions to provide comprehensive training.

[0003] Fitness strength machines with a stack of weights, also known as selectorized machines, are a common type of fitness machine. These machines typically have a stack of weights ranging from 45 kg to 200 kg, which is usually divided into increments of 5 kg or 10 lbs. The weights, often referred to as "iron weights," are connected with a cable and pulley system to provide the necessary resistance for various cable-based exercises. These machines are industry standards in commercial gyms and home fitness environments.

[0004] Fitness machines can be configured as, for example, a deep squat rack, a cable cross-training machine, a multi-functional trainer, a Smith machine, or a combination of a strength and Smith machine.

[0005] Examples of exercises that can be performed on a selectorized machine include high pulldowns, chest flys, seated row, shoulder press, and leg curls. A user can adjust the weight resistance by moving a pin between different weights, connecting the selected weights with the weight bar, thus being able to customize the exercise intensity.

[0006] However, this adjustment process can be inconvenient, as each adjustment requires the user to interrupt the exercise and leave the training position to change the weight by moving the pin. Furthermore, conventional machines are not equipped with sensors focused on analyzing and recording the combined weight moved by the first resistance source and the second resistance source.

[0007] There are fitness machine solutions on the market that use electric motors, flywheels, or magnetic braking systems to provide resistance instead of physical iron weights. These solutions rely on one (non-iron weight) resistance source to provide variable resistance to the user.

[0008] However, one disadvantage of these electromechanical resistance systems is that the user loses the tactile feedback experienced when using traditional physical weight blocks, as the iron counterweights are completely eliminated. When moving physical weight blocks, the user experiences the inertia, mass and gravity of the weight blocks, which enhances neuromuscular coordination when they control the weight blocks throughout the entire exercise. Furthermore, the visual perception of the movement of physical weight blocks also has a psychological and motivational effect. Experience shows that moving real weight blocks has a more positive effect on the motivation of the athlete.

[0009] Prior art

[0010] US20200254309 A1 and US 7163488 B2 both relate to a fitness machine comprising a barbell connected to two cables. These two cables are connected to an electromechanical resistance system that can be adjusted to assist or resist the lifting of the barbell. Therefore, these fitness machines comprise a hybrid resistance generation system.

[0011] Although the two machines disclosed in the above documents combine physical weight blocks with an electromechanical resistance system, they are specifically designed to work in conjunction with a free weight barbell. Therefore, the range of exercises that can be performed with this combination of resistance is limited.

[0012] US2014 / 228174 A1 relates to a strength training machine with automatic control of gravitational load. The user moves a weight block set through a cable and pulley system that is connected to a torsion spring located between two shafts. One shaft is connected to the cable system and the other shaft is connected to an electric motor. Sensors detect the rotational angle of both shafts and a processing unit controls the electric motor based on the angle difference to adjust the spring tension during use.

[0013] However, when the user pulls the weight block set through the user interface, the machine does not allow the electric motor to actively increase the resistance; the effective training load remains limited to the manually selected weight blocks and is not increased by the electric motor during the lifting.

[0014] US 5 476 428 A discloses an accessory for a weight block set fitness machine that provides more resistance during the centrifugal (downward) phase than the centripetal (upward) phase. The accessory comprises an electric motor, sensors and a controller that adjusts the torque based on the direction of movement and user input to increase the force when lowering the weight blocks through a cable or belt system.

[0015] Nevertheless, during the lifting phase, the electric motor does not essentially generate torque; it can only tighten the slack part without having an effect on the resistance. Therefore, the effective training load during the lifting remains limited to the weight plates manually inserted into the sockets and any centripetal overload or dynamic weight adjustment during the repetition cannot be achieved.

[0016] US 11 883 717 B2 describes a weight lifting apparatus with electrically assisted and resistive systems that can be dynamically adjusted during exercise. The apparatus includes weight plates connected to a user grip component through a cable and pulley system, proximity sensors for detecting the number of weight plates lifted, and position sensors for measuring speed and distance of motion. A system controller evaluates sensor data in real time and selectively activates an electric motor to assist or resist the user’s actions depending on the exercise situation.

[0017] However, this design has certain drawbacks. It has a complex and bulky structure that makes it impractical in many environments. Furthermore, force application to the cable is difficult to control precisely, resulting in limited responsiveness. The cable also suffers from greater mechanical wear due to continuous loading and motion, leading to higher maintenance requirements and potential reliability issues over time.

[0018] WO 2009 / 107904 A1 relates to a training device and system that uses electrically controlled rotating components, such as synchronous electric motors, to provide multiple exercise modes. The system includes a controller that adjusts the torque and rotational speed of the electric motor based on user input and sensor data. It supports multiple training modes, including isokinetic, isotonic, isometric, range of motion (ROM), and programming modes. Sensors measure torque, position, and speed to dynamically adjust the training load.

[0019] However, this system relies almost entirely on electric motor-generated resistance, which presents several drawbacks. In the event of a power outage or control failure, the resistance faced by the user is minimal or zero. Furthermore, since there is no set of physical weight plates, the familiar tactile experience associated with inertia-based resistance is lost, reducing the neuromuscular engagement and psychological commitment that are typically emphasized in traditional strength training.

[0020] Object of the invention

[0021] It is therefore the object of the present invention to eliminate the drawbacks of the prior art and to provide a hybrid resistance generation system for fitness equipment that can provide multiple exercise modalities without being limited to barbell-based training, enable easy weight adjustment for different training regimes, and provide a realistic tactile feedback. Summary of the invention

[0022] The object of the present invention is solved by the features of the independent claims. Advantageous embodiments of the invention are described in the dependent claims.

[0023] In a first aspect, the present application relates to a hybrid resistance generation system for an exercise machine, comprising a housing, a sensor system, a weight stack having a plurality of weight plates, and an electromechanical resistance module, wherein the plurality of weight plates are connectable with a weight bar providing a first resistance source, and the electromechanical resistance module provides a second resistance source. The first resistance source and the second resistance source are connected in series, such that a resultant resistance source acts on a first cable, which is preferably connected with the weight bar.

[0024] Integrating a weight stack having a plurality of weight plates and an electromechanical resistance module into a single resistance generation system of an exercise machine can provide a versatile workout experience, allowing the user to benefit from the tactile feedback of traditional weight plates, as well as the dynamic, software-adjustable and precisely controlled characteristics of electronic resistance. Physical weight plates, in particular the weight plates of a weight stack, can provide strong tactile feedback, allowing the user to feel the inertia, mass, and to visually see the movement of the weight plates, which can help to improve neuromuscular coordination and motivation. In contrast, all-electric systems can lack this advantage. The present application preserves the tactile and visual feedback of physical weight plates, while incorporating the advantages of electronic or electromechanical resistance.

[0025] A preferred resistance generation system for an exercise machine can achieve a non-linear force profile throughout a set, without the need to adjust the weight stack. While the user is using traditional iron weight plates, the electromechanical resistance module can dynamically increase or decrease resistance within a set, or even within a single repetition. This can create a dynamic muscle tension curve, which scientists generally agree is optimal for enhancing muscle strength.

[0026] Furthermore, a preferred hybrid resistance generation system for an exercise machine can be used for any exercise that is typically performed with traditional weight plates. This includes, but is not limited to, bench press, deep squat, and pull-up (the three main powerlifting exercises), as well as incline bench press, shoulder press, row, and high pull-down. A preferred hybrid resistance generation system is also suitable for exercise machines that can be adapted to a variety of forms and shapes of strength equipment. The main difference lies in the location of the hybrid resistance generation system within the exercise machine and the cable path. However, the main principle of combining physical weight plates and an electromechanical resistance module into a hybrid system remains consistent across different machines.

[0027] The proposed hybrid resistance generation system can also be implemented in a version that does not comprise a housing and / or a sensor system. These features are not essential.

[0028] For example, one advantageous embodiment can be configured as follows: A hybrid resistance generation system for a fitness machine includes a weight stack having a plurality of weight plates connectable to a weight bar providing a first resistance source. The system also includes an electromechanical resistance module providing a second resistance source, the electromechanical resistance module including a motor with a capstan onto which a second cable can be wound and unwound. The first resistance source and the second resistance source are connected in series, and the second cable interconnects the electromechanical resistance module and the weight bar such that a resultant resistance source acts on a first cable connected to the weight bar. The second cable is connected to a first end of the weight bar, and the first cable is connected to a second end of the weight bar, the first end and the second end being on opposite sides of the weight bar. Two pulleys direct the second cable from the electromechanical resistance module to the second end of the weight bar of the weight stack.

[0029] In another example, a hybrid resistance generation system for a fitness machine can include a weight stack having a plurality of weight plates connectable to a weight bar providing a first resistance source. An electromechanical resistance module provides a second resistance source, the electromechanical resistance module including a motor with a capstan onto which a second cable can be wound and unwound. The first resistance source and the second resistance source are connected in series, and the second cable interconnects the electromechanical resistance module and the weight bar such that a resultant resistance source acts on a first cable connected to the weight bar. The motor is designed as a brushless external rotor motor.

[0030] It is clear that the present application is not limited to the examples described above.

[0031] Generally, the weight stack is preferably a series of rectangular weight plates, typically made of metal, stacked together for (group) use by inserting a pin into the desired weight level. The user can adjust the number of weight plates by moving the pin to different weight plates, connecting the selected weight plates to the weight bar. Each weight plate has a through hole through which the pin can pass to engage the weight bar. The selected weight plates (or weight stack) are preferably guided up and down by a pair of vertical rods and a weight bar connected to the cable and located between the vertical rods.

[0032] In addition, the weight bar can include a shaft with axially spaced openings and a plate with a through hole that guides the vertical rods of the fitness machine. The design of the weight bar has a shaft with axially spaced openings to facilitate weight selection adjustment. The axially spaced openings are designed to accommodate a pin that connects the selected weight plates of the weight stack to the weight bar. The plate with a through hole of the weight bar guides the rod tube, ensuring smooth operation because the weight bar is always properly aligned to effectively engage the weight stack, resulting in a stable and safe lift.

[0033] Furthermore, in the present application, cables refer to strong, flexible wires or ropes used to transfer force and provide resistance during exercise. These cables are typically made of durable materials such as steel or high-strength synthetic fibers. They are designed to withstand high tension while connecting the various components of a fitness device or hybrid resistance generation system to enable smooth and controllable movement.

[0034] Since the hybrid resistance generation system comprises both a physical resistance source and an electromechanical resistance source, it is referred to as a hybrid system. Furthermore, since the hybrid resistance generation system can comprise a housing with at least two chambers, it can also be referred to as a chamber system. A particular feature of this chamber system is that it enables the connection of resistance sources (physical and electromechanical resistance sources) in series and the placement of the individual components in separate chambers.

[0035] Since the resistance sources are connected in series, a (total) resulting resistance source is created, which is obtained by the sum of the two resistances. Each resistance can be adjusted individually.

[0036] By placing the individual components of the hybrid resistance generation system in separate chambers, physical separation of the components is achieved. Depending on the components, this prevents electromagnetic interference or thermal cross-talk, or interaction between these components, thereby improving the overall performance of the system. Housing each component in a separate chamber also facilitates targeted maintenance or replacement of individual components without disturbing the other components, thereby improving maintainability; or for safety reasons, mechanically limiting user access to the chamber with the electric motor. The chamber design can be customized to the specific needs of each component, for example, to optimize cooling airflow for the electromechanical resistance module, ensuring that each component operates in its ideal environmental conditions.

[0037] In general, a housing can refer to a structural assembly or enclosure that surrounds, protects, and supports the internal components of a mechanical, electrical, or electronic system. It is typically used to shield sensitive components from environmental factors such as dust, moisture, vibration, or mechanical impact. In addition to providing protection, the housing also provides structural support and serves as a mounting base for internal elements. The housing can contain features that allow for mechanical connections, airflow circulation, cable routing, or maintenance access points. Furthermore, the housing can ensure user safety by preventing accidental contact with moving parts or live components.

[0038] The housing of the hybrid resistance generation system can comprise at least two chambers. These chambers can be individually customized for the components of the hybrid resistance generation system as described above. For example, the chambers can have different sizes and shapes. However, the housing does not necessarily consist only of chambers; it can also contain solid parts, for example, to ensure that the housing has sufficient weight and remains stable. The housing is preferably made of metal (such as steel, stainless steel, or aluminum), fiber-reinforced plastic, or plastic.

[0039] Furthermore, the housing can have openings, for example to make components enclosed by the housing visible. For example, the set of weights can be visible through the openings, so that the user can observe the movement of the individual weights. Some openings can also be closed by doors, so that components can be replaced, serviced or repaired without having to remove the entire housing.

[0040] Preferably, the chambers are designed to be separated from other chambers by a partition or wall, which can be integrated into the structure of the housing or added as a separate component. The partition ensures that each chamber forms a completely enclosed space, protecting the internal components from external influences. Depending on the specific requirements of the components housed, the chambers can differ in terms of temperature, air pressure or protective measures.

[0041] Furthermore, the shape of the chambers can vary depending on the specific requirements of the components, and they can be equipped with seals to prevent the ingress of foreign objects.

[0042] In a preferred embodiment, a second cable interconnects the electromechanical resistance module with the weight bar. This configuration connects the electromechanical resistance module as a second resistance source in series with the set of weights as a first resistance source.

[0043] In this case, the set of weights, in particular the weight bar, is connected to a first cable, which, when pulled, generates resistance through the weight of the set of weights. The resistance can be increased by adding more weight plates to the weight bar. When a pulling force is applied to the first cable, it exerts a pulling force on a second cable connected to the weight bar. The second cable in turn exerts a force against the electromechanical resistance module. Thus, when a user pulls the first cable through the set of weights, he also pulls the second cable connected to the electromechanical resistance module, effectively joining the two resistance sources in series.

[0044] The second cable can be connected to a first end of the weight bar, while the first cable can be connected to a second end of the weight bar, which are located on opposite sides of the weight bar with respect to its longitudinal axis. The first end of the weight bar can be oriented towards the electromechanical resistance module and can be used to receive and transmit the resistance generated by the electric motor through the second cable. The second end of the weight bar can be oriented towards the user side or the exercise handle and can serve as an output interface for applying the combined resistance to the user through the first cable. The arrangement of the first and second ends on opposite sides of the weight bar ensures that the resistance from the mechanical and electromechanical resistance sources can act in series on the weight bar in a balanced and controllable manner.

[0045] In particular, the term "end" can refer to the respective axial end of the weight bar. For example, this can correspond to the uppermost or lowermost 0 mm to 100 mm of the shaft length, depending on the total length and the specific configuration of the mechanical interface. By way of example, in a weight bar with a total shaft length of 600 mm, the "ends" can be defined as the terminal 50 mm of either end, which are typically used to accommodate mechanical connectors, interface elements or cable connections.

[0046] A plate can be arranged at the upper end (second end) of the shaft, allowing the first cable to be connected directly to the plate. For example, the longitudinal axis of the weight bar can extend over a length of about 300 to 800 mm, with a shaft diameter of between 20 and 50 mm, depending on the required strength and stiffness. The first end can comprise a mechanical interface (such as a threaded hole, a clevis connector, a flange mount or an adapter connection) configured to receive the pulling force transmitted by the second cable from the electromechanical resistance module. The upper end (second end) can carry a rectangular or circular plate element, for example with dimensions of 60 mm x 40 mm and a thickness of 5 mm, made of stainless steel or aluminum, to which the first cable can be connected.

[0047] In certain exemplary embodiments, the weight bar comprises no more than two cable junctions, such that it is connected to only two separate cable ends, and not to more than two cables, nor to both ends of a single cable.

[0048] By having the second cable continuously connected to the weight bar, the electromechanical resistance module remains in an "always on" mode. This means that the electromechanical resistance module is preferably always powered on and continuously activated to retract the second cable after it has been lengthened, even when the electromechanical resistance module does not exert any resistance during the exercise. The hybrid resistance generation system is preferably specifically designed so that the user can always pull both cables in series. If the user chooses the mode of pulling only the physical weight blocks (i.e. the weight blocks of the weight block set), the electromechanical resistance module provides almost zero resistance, just enough to pull in the second cable.

[0049] In this regard, the user does not need to manually switch between resistance sources. The user can start the exercise with the physical weight blocks (i.e. the weight block set) and switch to a hybrid resistance exercise by a simple voice command or by pressing a control element (preferably with only one finger, such as a button or a rotary adjustment ring on the user interface). The electromechanical resistance module is preferably always connected to the grid power supply for on-demand power supply and can be connected to the user's smartphone via Bluetooth or Wi-Fi.

[0050] To ensure continuous operation, a power supply is provided to power the electromechanical resistance module. This can be achieved in various ways. The proposed hybrid generation system or electromechanical resistance module can comprise a battery and / or a solar panel, or can have a connection that allows it to be plugged into the grid.

[0051] The inclusion of the second cable as a connection between the weight block set (as the first resistance source) and the electromechanical resistance module (as the second resistance source) forms a stable connection that enables direct and immediate force transmission. The system also has flexibility, allowing the weight block set and the electromechanical resistance module to be positioned relative to each other as needed, and guiding the cables within the housing using pulleys.

[0052] Preferably, the hybrid resistance generation system comprises at least one pulley guiding the second cable to the weight bar of the weight stack. This design enables a smooth connection between the weight bar and the electromechanical resistance module. Furthermore, the pulley helps to manage the load on the second cable, which is beneficial to improve the durability and prolong the service life of the system. Preferably, the pulley is attached to the housing or the frame of the housing.

[0053] A pulley is preferably a wheel mounted on an axle designed to facilitate the movement of a cable, rope, or belt and change its direction. It preferably has a groove or channel to hold the cable securely in place. Typically, it comprises bearings to ensure smooth operation and is made of durable materials such as metal or high-strength plastic. The pulley is usually mounted on a sturdy bracket attached to the system or machine. Some pulleys have adjustment mechanisms to change the height or angle and contain safety features such as guards to prevent the cable from slipping and protect the user. The wheel and groove have a smooth surface to minimize wear on the cable, and the entire assembly is preferably rated for a specific load capacity to ensure safe and efficient operation.

[0054] In some embodiments, two pulleys guide the second cable from the electromechanical resistance module to the second end of the weight bar of the weight stack. In this regard, the two pulleys can be arranged such that the pulleys and / or the second cable are always located below the second end of the weight bar relative to the ground, regardless of whether the weight bar is moving upwards, downwards, or is in a stationary position.

[0055] The two pulleys can each be rotatably mounted on a respective axle or support arm, which in turn is fixed to the frame of the fitness machine or a guide structure associated with the housing of the weight stack or the hybrid resistance generation system. The pulleys can be arranged such that the cable path between the electromechanical resistance module and the weight bar maintains a section oriented downwards, regardless of the current vertical position of the weight bar.

[0056] The term "below the second end of the weight bar" is preferably to be understood in a spatial sense, referring to the relative positioning of the pulleys and the cable path relative to the direction of gravity. Specifically, the pulleys remain in a position directly below the cable connection point at the second end of the weight bar, even when the weight bar is in a lowered or raised position. This ensures that the section of the cable between the last pulley and the weight bar always extends upwards from the pulley to the cable connection point and does not sag, flip, or cross over the weight bar.

[0057] This arrangement yields several technical advantages. First, it minimizes the risk of cable misalignment, entanglement or contact with other moving parts such as weight plates, guide rods or frame elements. Second, by maintaining a consistent directional geometry of the cable, force transmission from the electromechanical resistance module to the weight bar remains stable, predictable and free of angular bias, which contributes to improved mechanical efficiency and precise resistance control. Furthermore, the defined pulley layout enables compact integration into the vertical structure of the machine and supports modular assembly.

[0058] In another preferred embodiment, the weight stack is located in a first chamber and the electromechanical resistance module is located in a second chamber. Placing the weight stack and the electromechanical resistance module in separate chambers can reduce interference between the two components. For example, the chamber housing the weight stack can be designed to effectively absorb vibrations, preventing any impact on the electromechanical resistance module and its sensitive electronic components.

[0059] Furthermore, the division of the chambers can be tailored to meet the specific requirements of the weight stack or the electromechanical resistance module, yielding overall structural advantages. For example, the chamber containing the electromechanical resistance module can be independently cooled. This means that only a relatively small chamber needs to be cooled, rather than the entire housing, thereby reducing the cooling power and energy required by the system.

[0060] It is apparent that the weight bar can also be housed in the same chamber as the weight stack and can be considered part of the weight stack. It is possible for a part of the weight stack and the weight bar to remain in the initial position within the chamber. However, when the weight bar is pulled out, it can exit the chamber together with the weight plates of the weight stack that are connected to the weight bar.

[0061] Preferably, the electromechanical resistance module refers to a device that provides adjustable resistance during exercise using electrical and mechanical components. This module can precisely control the resistance level electronically, providing a dynamic and customizable exercise experience. Examples include electric systems or flywheels that use electromagnetic brakes to adjust resistance.

[0062] The electromechanical resistance module can contain an electric motor with a capstan on which the second cable can be wound and unwound. Combining an electric motor with a capstan for winding and unwinding the second cable improves the accuracy and reliability of resistance adjustment, enabling smooth transitions and stable resistance levels during operation. The advantage of using an electric motor is that the resistance level can be automatically controlled, which can be adjusted through programming to suit various exercise programs, thereby providing a customized exercise experience for the user. The capstan mechanism enables compact storage of the second cable when not in use. The electric motor is preferably a servo motor, a DC motor and / or a brushless DC motor, ensuring high-precision control of cable movement, enabling precise adjustment and maintaining stable tension throughout the exercise.

[0063] In an electromechanical resistance module, a capstan can refer to a rotatable spool or reel specifically configured to wind and unwind the second cable in a controlled manner. The capstan typically operates between two defined states: a winding state and an unwinding state. The winding state refers to a configuration in which the second cable is wound in at least one full loop or turn on the spool. In contrast, the unwinding state corresponds to the cable being released from the spool, reducing the number of winding turns and lengthening the cable length available to exert resistance.

[0064] The capstan can secure or anchor a first end of the second cable to the capstan or spool or reel of the capstan (referred to as the anchor end), while the other end of the cable (referred to as the free end) extends outward from the capstan and is configured to transmit force during operation. The anchor end ensures reliable torque transmission from the capstan to the cable, while the free end allows for controlled interaction with other system components, such as the weight bar or user interface, depending on the direction and extent of cable movement.

[0065] It is particularly preferred that the electromechanical resistance module employs a brushless external rotor motor. Such a motor has the advantage of operating without a gearbox, simplifying the design of the electromechanical resistance module, and is particularly efficient. In this configuration, the electric motor can be directly connected to the capstan.

[0066] Alternatively, other implementations can also be employed in which a gearbox can be provided between the electric motor and the capstan to provide additional mechanical advantage and control cable movement.

[0067] Furthermore, the electromechanical resistance module may, for example, contain electric servo motors, each with a power range of between 500 W and 1000 W, as well as a servo driver, a controller board, a ground cable, and a Bluetooth communication chip. Other configurations can also be employed in which electric servo motors with a power range of 50 W to 4000 W or 250 W to 1200 W are used. The servo motors are not limited to these ranges.

[0068] In another preferred implementation, the weight block group is located in a first chamber, the electric motor is located in a second chamber, and the capstan is located in a third chamber. This facilitates maintenance and repair, as each component can be individually accessed without interfering with the other components.

[0069] The second chamber and / or the third chamber can be located below the first chamber. In this way, the weight bar can be located above the capstan, enabling the second cable to extend from below to the lower end of the weight bar, thereby enabling a simple and direct connection between the capstan and the weight bar. It will be appreciated by those skilled in the art that an opening can be provided at the bottom of the first chamber, through which the second cable and / or the weight bar can reach the third chamber below.

[0070] Furthermore, the electromechanical resistance module can comprise a control unit having a data processing unit for controlling the second resistance source and a communication unit for data communication. The inclusion of a control unit with a data processing unit, especially in combination with sensors for measuring the moved traditional iron weight blocks and the provided electrical resistance, enables the hybrid resistance generation system to provide dynamic resistance adjustments based on real-time feedback. This can improve the effectiveness of the workout by automatically adjusting the resistance according to the user’s performance. The communication unit allows for data exchange with external devices or networks, making remote monitoring, software updates, and integration with fitness tracking systems possible. The ability of the control unit to manage the second resistance source, especially the electromechanical resistance module, ensures a seamless and user-friendly experience as it can automatically calibrate the resistance levels in response to programmed workout programs or user preferences.

[0071] In another preferred embodiment, the hybrid resistance generation system can comprise a sensor system configured to acquire the resistance of the first resistance source and / or the second resistance source and / or the resulting resistance source, and / or the movement of the weight block set and / or the weight bar, and / or the movement of the first cable.

[0072] Preferably, the sensor system comprises at least one sensor, a battery, and a communication unit. Furthermore, the sensor system can comprise a data processing unit, a memory, and / or a housing accommodating all components.

[0073] The sensor system provides real-time feedback and higher precision, ensuring resistance stability for effective workouts. It enables customization of personalized workout plans according to individual needs and goals, while preventing injuries by monitoring force and movement, thereby improving safety. Users can track their progress and performance, and the control unit of the electromechanical resistance module can automatically adjust to provide an optimized workout experience. The system enhances engagement and motivation through real-time data, making workouts more efficient, and enables seamless integration with fitness applications for comprehensive tracking and goal setting.

[0074] For example, the signals or acquired data from the sensor system can be combined, analyzed, cloud-stored, and displayed to the user through a software application running on an external device such as a smartphone or tablet. The software application can also be configured to control the main settings of the electromechanical resistance module, including setting the resistance, switching between kilogram / pound units, and providing predefined workout programs for the user.

[0075] Preferably, the user interface of the electromechanical resistance module and / or the sensor system and / or the fitness machine can be in data communication with an external device having a data processing unit and a communication unit. The sensor system can comprise means for providing the acquired data to the external device. The user interface can comprise means for providing input signals to the external device.

[0076] In another preferred embodiment, the sensor system can comprise a laser device. The laser device can be located below the lowermost weight plate of the weight stack or above the plate of the weight bar and be directed towards the pin of the weight stack. Preferably, the laser device is configured to emit a laser beam towards the pin and to calculate the distance of movement of the weight stack and the number of repetitions completed by analyzing the reflection of the laser beam. This information can be important for the functioning of the hybrid weight system as it can automatically and dynamically adjust the motor resistance based on the weight of the physical weight selected by the user and the performance information of the user in a particular exercise.

[0077] Preferably, the laser device is a distance, range or proximity measuring device. When the laser device is directed towards the pin, it specifically measures the distance between the laser emission point on the laser device and the pin of the weight stack. The pin preferably has a highly reflective surface ensuring that the reflected light returns to the laser device without interference. The laser device is preferably equipped with a sensor, such as a photodiode, to effectively analyze the reflected light beam.

[0078] The laser device can be aligned so that it is located a certain distance below or above the pin. The pin preferably comprises a shaft and a plug. The laser beam is specifically directed towards the plug, while the pin shaft is inserted into the weight stack and connects the individual weight plates or weights to the weight bar. The laser beam is preferably emitted or directed in a generally perpendicular direction from below or above the plug. Each weight plate of the weight stack has a predetermined distance from the laser device, which enables the laser device to detect which weight plates are connected to the weight bar and the weight the user is lifting. Furthermore, the laser device can detect the progress and completion of a repetition by monitoring the continuous change in distance.

[0079] It will be appreciated by the skilled person that the laser device can have its own control unit equipped with a data processing unit, a memory and / or a communication unit, which can be in data communication with the control unit of the electromechanical resistance module or an external device.

[0080] In an alternative embodiment, the sensor system comprises a load cell, a three-axis accelerometer, a battery, a communication unit and / or a data processing unit, wherein the load cell interconnects the first cable connected to the user interface of the fitness machine and the weight bar of the weight stack. In particular, the load cell can be connected to one end of the first cable and be fixed directly to the weight bar.

[0081] In some example embodiments, the winch can be connected with a rotary encoder configured to detect the angular position or rotational speed of the spool. The control unit can be configured to monitor the encoder signal to determine the cable tension or displacement during operation.

[0082] In this regard, the load cell converts the force into an electrical signal by measuring the deformation or strain of the material when the load is applied. It is preferably connected to the top of the weight bar. A tri-axial accelerometer, which can be attached to the back of the load cell, is used to measure acceleration and the distance of movement of the weight bar along three perpendicular axes (X, Y, and Z axes). Such tri-axial accelerometers are commonly used in smartphones, for example, to detect motion and orientation. A rechargeable battery can also be located on the back of the load cell and powers the sensor system.

[0083] Furthermore, the external device can be configured to process the data provided by the sensor system and / or the input data provided by the user interface, and / or to transmit control instructions to the electromechanical resistance module. The integration of the electromechanical resistance module and the sensor system in data communication with the external device enhances the interactivity and personalization of the exercise experience, as it enables real-time tracking and adjustment of the exercise parameters based on the user’s performance. The ability of the external device to process the sensor data and the user input and transmit control instructions to the electromechanical resistance module enables the implementation of advanced training programs and protocols that dynamically adapt to the user’s needs and progress.

[0084] The external device can be a smartphone, a tablet, a smartwatch, a computer, or any other device with data processing and communication capabilities (but not limited to these options).

[0085] The design of the system facilitates seamless integration with existing technological ecosystems, such as smartphones or computers, allowing the user to leverage their devices for additional functionalities, such as exercise logging, social sharing, or access to a wider range of digital fitness services.

[0086] In another preferred embodiment, the hybrid resistance generation system can include at least one display capable of displaying data processed by the control unit of the electromechanical resistance module and / or the control unit of the sensor system. The display can be designed as an LCD display and located on the side wall or front face of the housing of the hybrid resistance generation system, so that the user can see the LCD display during the exercise. The display can display data processed by the control unit of the sensor system, the external device, or the electromechanical resistance module, such as weight measurements in kilograms (KG) or pounds (LBS), providing the user with real-time feedback and interaction with the hybrid resistance generation system. The display can also be a smartphone that is magnetically attached to the housing and wirelessly charged via a wireless charger stand.

[0087] The hybrid resistance generation system can further include an adapter that allows the second cable to be detachably connected to the weight bar without the use of tools.

[0088] For example, in a simple implementation, the adapter can comprise a hook, a clevis, a snap pin, a bayonet joint, or other positive locking mechanism that enables a secure yet reversible engagement with minimal manual manipulation. The connection can be achieved through axial insertion and rotation, snap-locked engagement, or a spring-loaded latching mechanism, allowing the user or technician to connect or disconnect the cable without the use of manual tools such as wrenches or screwdrivers.

[0089] In another general example, the second cable can terminate in a connector such as a ball end, a loop, or a ring that can be introduced into a receiving profile of the adapter. Upon insertion, the adapter automatically locks the cable end in place, ensuring that the pulling force during exercise is reliably transmitted to the weight bar. To disconnect, the adapter can have an actuation element such as a button, a sliding ring, or a tab that releases the lock and allows the cable end to be removed.

[0090] The tool-free detachable interface has several advantages. It enables quick reconfiguration of the hybrid resistance system, for example, when switching between different exercise modules, replacing components, choosing to train without the hybrid system and using traditional weight plates only, or adjusting the setup for different users. It also simplifies maintenance and / or transportation, as the electromechanical resistance module can be disconnected from the weight bar within seconds without the need to disassemble larger parts of the machine. Furthermore, the tool-free connection reduces the risk of user error and improves safety, as there is no risk of improperly tightened bolts or missing hardware components affecting the cable connection. Overall, the integration of a tool-free adapter for detachably connecting a second cable to a weight bar improves the modularity, ease of use, and system flexibility of the hybrid resistance generation system.

[0091] The adapter can be configured to detachably connect the second cable to the weight bar through a positive and / or force-locked connection. Configuring the adapter to detachably connect the second cable to the weight bar through a positive and / or force-locked connection provides a safe and tool-free mechanism for assembling or disassembling the electromechanical resistance module. It also facilitates maintenance and transportation operations while ensuring reliable force transmission during exercise without the risk of accidental disconnection.

[0092] In this application, a positive-locked connection can refer to a mechanical connection that secures the second cable to the weight bar through a geometrically matching interface. Such a connection typically relies on interlocking shapes, such as a bayonet mount, snap features, or groove-pin structures.

[0093] A force-locked connection (also known as an interference fit or a friction fit) can refer to a connection that relies on friction generated by pressing or clamping two components together. Examples include a clamping sleeve, a captive screw, or a spring-loaded locking mechanism that holds the cable under tension.

[0094] The adapter can be divided into sections with different functions, wherein a first section can be configured to receive the second cable and can secure this cable by means of a clamping connection. A second section of the adapter can be configured to establish a detachable connection between the adapter and the weight bar.

[0095] The term "first section" can refer to a structural section of the adapter which is configured to receive and secure the second cable. It is preferably formed as a sleeve or hollow cylinder with an axial through-hole into which the second cable can be inserted. The main function of the first section is to establish a force-transmitting connection between the second cable and the adapter, thereby enabling a reliable load transfer during operation of the hybrid resistance system.

[0096] To achieve this, the first section can be designed to secure the second cable by means of a clamping connection. For example, this can be achieved by means of a threaded hole provided on the sleeve side wall into which a set screw is inserted. Upon tightening, the set screw radially presses against the cable, forming a secure frictional fixation. Alternatively, the clamping connection can be formed by means of a collet structure, a press-fit interface or an integrated conical insert which wedges the cable in place. In all cases, the clamping mechanism ensures that the cable is securely fixed when subjected to tensile loads, but can be released or reinserted without the need for special tools.

[0097] In another example, the clamping connection is established by means of three screws which are screwed into corresponding threaded holes on the sleeve side wall, thereby pressing and securing the second cable within the sleeve.

[0098] The first section can further comprise features which reduce mechanical wear of the cable, such as an internal guide sleeve or a low-friction bushing. Its size and shape can also be designed to prevent rotational displacement of the cable relative to the adapter body, thereby ensuring correct alignment of forces. The geometry of the first section can be adapted to the cable diameter and can comprise an external gripping surface or reinforcement for ease of handling. The material of the first section is preferably selected from metals such as aluminum or stainless steel, or high-strength polymers or fiber-reinforced composites, to ensure durability and lightweight construction.

[0099] In the present invention, the term "sleeve" can refer to a generally tubular or cylindrical component which defines a longitudinal opening along its central axis. The sleeve is configured to receive an elongated element, in particular the second cable, and to guide, support or secure this element within the adapter body. The sleeve can constitute a part of the first section of the adapter and serve as the primary interface for engaging the cable by means of a clamping or locking mechanism.

[0100] The sleeve can be integrally formed with the adapter or provided as a separate component secured therein. It can include internal structural features such as guide bushings, friction pads or conical seats to enhance alignment, reduce wear and improve reliability of force transmission between the cable and the adapter. The sleeve can also include external geometric features such as flats, knurling or grooves that facilitate manual operation or integration into adjacent components.

[0101] According to embodiments, the sleeve can be open-ended or closed on one side and dimensioned to receive the cable in a press-fit, slide-fit or loose-fit manner. In configurations involving a pinch connection, the sleeve preferably includes at least one threaded hole into which a set screw or equivalent fastener can be inserted to apply radial pressure to the cable. The sleeve is preferably made of a rigid, durable material such as aluminum, stainless steel or high-performance polymer selected to ensure structural stability under cyclic tensile loading.

[0102] In other words, the sleeve of the first portion can include an axial opening for receiving the second cable, and the opening includes an integrated cable guide or bushing configured to reduce friction and wear during movement of the second cable.

[0103] The term "second portion" can refer to a portion of the adapter configured to establish a detachable mechanical connection between the adapter and the weight bar. While the first portion secures the second cable, the second portion interfaces with the weight bar in a manner that allows for quick assembly and disassembly, preferably without the need for tools. The design of the second portion is optimized to ensure both robust force transmission and ease of operation during setup, adjustment or maintenance.

[0104] The connection established by the second portion can be based on a positive locking principle, a force locking principle or a combination of both.

[0105] In one embodiment, the second portion can be configured as a quick-release coupling that includes an automatic locking mechanism and a manually actuated release element. For example, the second portion can include an outer sleeve that is axially movable relative to a fixed core, with a locking element such as a ball detent that engages a corresponding groove on the weight bar. Retraction of the outer sleeve disengages the lock, enabling tool-free separation. This design ensures that tensile forces acting on the second cable do not inadvertently release the connection.

[0106] The outer sleeve can be biased into the locked position by a spring element disposed between the outer sleeve and the fixed core. In this configuration, the spring ensures that the outer sleeve is automatically maintained in its forward (locked) position, in which the positioning ball is radially inwardly constrained and securely engaged with the groove of the weight bar. To release the connection, the outer sleeve can be manually pushed rearward against the spring force to the unlocked position, in which the positioning ball is free to move radially outwardly and thus disengage from the groove. This construction provides both a secure hold during use and reliable tool-free disconnection when desired.

[0107] The groove on the weight bar can be provided by a separate protrusion inserted into an axial bore at the first end of the weight bar, which is secured in the bore by a press fit, adhesive bond, or threaded connection.

[0108] Alternatively, the second portion can comprise a rotatable locking nut mounted on the fixed adapter body, which is threadably connected to a mating external thread provided on the weight bar. This configuration allows the user to secure or release the connection by rotating the nut while the rest of the adapter remains rotationally fixed relative to the cable. Other variants can employ a bayonet coupling, pin-and-slot mechanism, or snap features with tactile locking indicators.

[0109] The second portion can also comprise alignment features, locators, or stop elements that aid in precise positioning and prevent misorientation during connection. The material used for the second portion can be selected to withstand high tensile loads and repeated connection cycles, and can include high-strength metals such as stainless steel or aluminum alloys, as well as fiber-reinforced plastics. Additionally, the outer surface can be knurled or textured to provide a secure grip when manually operated.

[0110] In another exemplary embodiment, the adapter can be configured to detachably connect with the weight bar through a bayonet coupling or pin connection.

[0111] In the case of a bayonet coupling, the adapter can be inserted over a mating protrusion of the weight bar and then rotated into a locked position. In contrast, for a pin connection, a locking pin can be inserted into aligned openings in the adapter and weight bar to secure the connection. Both configurations are designed to enable tool-free connection and disconnection, and to withstand tensile forces acting on the second cable without accidental release.

[0112] As used herein, the term "mating protrusion" can refer to a protruding structural element provided on the weight bar, which is configured to engage with a correspondingly shaped groove or connection feature of the adapter. The correspondingly shaped groove or connection feature of the adapter can be located at the second portion of the adapter. The mating protrusion is useful for guiding and supporting the adapter during assembly, and enables a secure mechanical connection between the adapter and the weight bar. The mating protrusion can be integrally formed with the weight bar, or can be configured as a separate component that is fastened to the weight bar by means of screws or welding, among others.

[0113] In one exemplary embodiment, the mating protrusion can include a generally cylindrical or slightly tapered shaft portion extending from the lower end of the weight bar. The protrusion can include one or more axially oriented slots or bayonet tracks configured to receive corresponding lugs or pins of the adapter. Upon axial insertion of the adapter into the mating protrusion, relative rotational movement of the adapter causes the lugs to engage behind locking surfaces of the protrusion, thereby forming a bayonet connection. The mating protrusion can further include a stop surface and / or a detent feature to limit rotational movement and ensure that tactile or audible feedback is provided upon reaching the locked position.

[0114] The term "alignment openings in the adapter and weight bar" can refer to a pair of corresponding through-holes or openings formed in the adapter and weight bar, respectively. The openings are positioned such that, when the adapter is installed in the intended connection location on the weight bar, the openings are axially or laterally aligned with each other, thereby allowing a locking element (such as a pin, bolt, or spring-loaded latch) to be inserted through both components to secure the connection.

[0115] In one exemplary embodiment, the adapter can include a transverse hole extending through its connection portion (second portion), while the weight bar includes a corresponding hole or recess at a matching height. Upon assembly, the holes are aligned, and a locking pin can be inserted to provide a positive (force-fit) connection that resists axial displacement. The pin can be secured by a spring clip, ball-and-socket detent mechanism, or threaded head to prevent accidental release.

[0116] Preferably, the alignment openings and locking pin are sized and toleranced to enable tool-free insertion while ensuring adequate retention. The locking pin can also include a grip portion or pull ring for quick removal. This configuration is particularly suitable for applications where rotational locking (as used in a bayonet coupling) is impractical or undesirable, and enables simple, robust, and repeatable assembly of the adapter and weight bar.

[0117] It will be appreciated that the holes required for alignment with the weight bar are provided in the second portion of the adapter. In a simple embodiment, the second portion can be designed as a sleeve that is inserted into a corresponding protrusion or mating protrusion of the weight bar, both components having respective alignment holes. Alternatively, the weight bar can include a sleeve into which a protrusion or mating protrusion of the second portion of the adapter is inserted, again with both components including matching holes to accommodate the locking pin.

[0118] In other words, in the case of a pin connection, the mating protrusion can instead be provided with a transverse through-hole or hole aligned with a corresponding opening in the adapter, allowing a locking pin to be inserted to secure the connection. In either configuration, the mating protrusion is sized and arranged to transmit the tensile forces acting on the second cable and prevent accidental disengagement of the adapter from the weight bar during operation.

[0119] The hybrid resistance generation system can further comprise a holding device configured to hold the adapter in a defined position relative to the winch when the adapter is detached from the weight bar to prevent the adapter from falling to the ground.

[0120] In this regard, for example, the housing or frame of the hybrid resistance generation system can comprise a holding plate which is generally aligned with the weight plates of the weight stack and arranged below the lowermost weight plate. The holding plate can comprise a through hole through which the second cable passes and the adapter is dimensioned such that it cannot pass through the through hole, thereby forming a mechanical stop which holds the adapter when it is detached from the weight bar.

[0121] The phrase "generally aligned with the weight plates" can refer to the holding plate of the hybrid resistance generation system extending in a plane which is parallel to the horizontal plane defined by the main surfaces of the weight plates. This means that the holding plate has the same orientation as the weight plates with an angular deviation of preferably less than 5°, more preferably less than 2°. The holding plate can be located below the lowermost weight plate with a vertical distance of preferably 5 mm to 500 mm, more preferably 10 mm to 100 mm.

[0122] The adapter is dimensioned such that its outer geometry, in particular the outer diameter of its connecting portion or holding flange, exceeds the diameter of the through hole in the holding plate. In particular, the maximum lateral dimension of the adapter can be at least 2 mm to 20 mm larger than the diameter of the through hole, thereby ensuring that the adapter can be mechanically blocked by the holding plate when it is suspended by the second cable. This dimensional relationship provides a reliable form-fit stop which does not rely on friction or active locking elements and ensures that the adapter cannot accidentally fall out of the opening of the plate even under dynamic or vibrational load conditions.

[0123] The mechanical stop formed by the holding plate and the through hole serves as a passive holding element which supports the adapter from below when it is no longer connected with the weight bar. Upon detachment, the adapter is lowered until its enlarged portion, such as a connecting flange or a housing shoulder, comes into contact with the upper surface of the holding plate. This contact prevents further downward movement and thereby mechanically holds the adapter in a defined vertical position. The stop does not rely on additional fasteners, clamps or user intervention, so that the adapter can be placed in a tool-free and fail-safe parking position when not in use. This arrangement also protects the adapter and surrounding components from impact damage and facilitates efficient reconnection.

[0124] The adapter can be made of a material selected from the group consisting of aluminum, stainless steel, reinforced polymers and fiber-reinforced composites.

[0125] Furthermore, the adapter can comprise a locking indication element, such as a colored marking, a positioning notch or a mechanical stop, which is configured to provide a visual or tactile indication of the correct locking position of the adapter relative to the weight bar.

[0126] Locking indicator elements are used to help the user confirm whether the adapter has reached the intended locking position relative to the weight bar. For example, only when the adapter is fully inserted and rotated into the correct position, a colored marking on the adapter surface will visibly align with a corresponding reference line on the weight bar. Alternatively, a positioning notch or groove can engage with a spring-loaded element, such as a ball or pin, creating a tactile or audible feedback (“click”) upon correct locking. In some embodiments, the locking indicator can be integrated into a mechanical stop that limits further rotation beyond the intended position, thereby ensuring a defined connection geometry. These features contribute to an intuitive, repeatable and error-resistant assembly, even in low-light or highly distracted environments, such as gym environments.

[0127] The adapter can be rotationally symmetric about the central axis and can include knurled or textured gripping surfaces on its outer circumference, configured to facilitate manual connection and disassembly without the use of tools.

[0128] To disassemble the adapter from the weight bar, a method can be provided that enables quick and tool-free separation of the components. The method can include manually releasing the locking element of the adapter without the use of tools, for example by actuating a spring-loaded latch, rotating a locking collar or disengaging a bayonet-style mechanism. Once the locking element is released, the method can further include disengaging the adapter from the shaft portion or connection structure of the weight bar, for example by pulling the adapter in the axial direction or rotating the adapter in the opposite direction to the locking direction. Finally, the method can include separating the second cable from the adapter, thereby decoupling the electromechanical resistance module from the weight bar and placing the system in a separated state suitable for weight-only operation or maintenance. This sequence of steps ensures a safe, intuitive and reversible disassembly of the hybrid resistance system.

[0129] In another aspect, the present application relates to a fitness machine. The fitness machine comprises a main body, a hybrid resistance generation system according to any of the above embodiments, and at least one pulley attached to the main body guiding the first cable to a user interface for exerting force against the resulting resistance source, wherein the user interface is attached to the first cable.

[0130] In a preferred embodiment, the fitness machine is designed as a squat rack accessory, a standalone tower, a squat rack, a half rack, a squat rack or a power and smith combination machine. The design of this fitness machine facilitates easy integration in home gyms and professional fitness centers, improving space utilization and investment value by enabling multiple uses and supporting a wide range of exercise modalities.

[0131] A deep squat rack is preferably a large cage-like structure with four vertical columns and horizontal bars at the top and bottom. It typically includes adjustable j-hooks and safety bars that can be moved to different heights. The equipment is versatile and can perform a variety of exercises in addition to deep squats, such as bench press, overhead press, and deadlifts. Deep squat racks come in a variety of sizes and variations, including half racks, wall racks, and folding racks, each preferably having four or more columns.

[0132] A deep squat rack is preferably a simple form of a deep squat rack. It includes two vertical columns or separate connecting units for supporting a barbell at a fixed or adjustable height. A high pulldown device or a smith machine can also be attached to the deep squat rack.

[0133] A strength machine is preferably a piece of exercise equipment designed to assist users in performing resistance training. These machines typically use weight stack sets, hydraulic resistance, or other mechanisms to provide adjustable resistance. Strength machines guide the user's movements along a fixed path, which helps ensure proper form and reduces the risk of injury. They are commonly used in gyms, fitness centers, and home exercise facilities.

[0134] A smith machine is preferably a weight training device integrated into a strength machine or deep squat rack, consisting of a barbell fixed within steel rails that allows the barbell to move vertically along a guided path. It is preferably designed for performing exercises such as deep squats, bench presses, and shoulder presses. The barbell can be locked at different heights using safety catches.

[0135] A multi-functional training rack is preferably a piece of exercise equipment used for bodyweight exercises targeting the upper body and core. It typically includes training stations for pull-ups, negative pull-ups, dip exercises, push-ups, and vertical leg raises. The structure of the multi-functional training rack is preferably composed of a freestanding frame with padded grips and back support to facilitate these exercises.

[0136] Typically, the user interface of a piece of exercise equipment allows the user to exert force against resistance to exercise muscles. The user interface can take various forms, including (but not limited to) a single handle, a long bar handle, a high pulldown handle, a cable, and others.

[0137] Furthermore, embodiments can also employ a user interface comprising means for providing input signals to the control unit of the electromechanical resistance module. The user interface provides the functionality of inputting signals to the control unit, allowing the user to easily customize their own workout experience by selecting the desired resistance level, exercise duration and other parameters, thereby increasing user satisfaction and the degree of exercise personalization. The means for providing input signals can include various user-friendly options such as buttons, rotary adjustment rings, touchscreens or microphones for voice commands, which can improve operability. By enabling the user to directly interact with the control unit of the electromechanical resistance module, the user interface facilitates immediate adjustments to the workout, allowing the user to quickly react according to their comfort level and performance, which contributes to a more effective and enjoyable workout process. The user interface preferably comprises a communication unit and a rechargeable battery, which allows the transmission of input signals to the electromechanical resistance module. It can also comprise a memory or a data processing unit.

[0138] Preferably, the user interface is designed as a handle with a rotary adjustment ring and tactile buttons, allowing the user to increase, decrease or stop the electromechanical resistance. This technique can be considered as single-thumb control, which can be operated with only one finger. The handle is preferably provided in different sizes and shapes according to the exercise.

[0139] The user can start training with only the physical weight and activate the electromechanical resistance from the electromechanical resistance module by simply rotating the thumb on the handle. The handle can be battery-powered, which can be charged by plugging a USB-C cable directly into the electromechanical resistance module. The signals from the handle can be transmitted wirelessly to the electromechanical resistance module.

[0140] In another aspect, the present application relates to a method for adjusting the force a user has to apply to a fitness machine according to the above-mentioned embodiments.

[0141] The method can comprise the steps of applying the force by the user interface against the synthetic resistance source and / or acquiring the movement, in particular the speed and / or acceleration of the movement, of the weight of the set of weights by the sensor system and / or providing the data acquired by the sensor system to the control unit of the electromechanical resistance module and / or detecting a decrease in speed and / or acceleration with respect to the data previously acquired by the sensor system by the control unit and adjusting the second resistance source by the control unit of the electromechanical resistance module.

[0142] The method can automatically respond to the user's state with the captured sensor data and adjust the resistance of the electromechanical resistance module accordingly. For example, when the sensor system detects that the user is tiring (indicated by slowing down the repetitive movements), it will decrease the electromechanical resistance. This enables the user to continue the exercise without having to stop due to excessive weight or fatigue, a feature that cannot be achieved with traditional fitness machines that include iron weights.

[0143] Alternatively, the method can comprise the steps of exerting a force through the user interface against the synthetic resistance source, or providing an input signal to the control unit through the user interface, and adjusting the second resistance source by the control unit of the electromechanical resistance module. The resistance can be adjusted by the user input during the exercise only by moving one thumb, which provides a high degree of flexibility in the exercise program, allowing the user to quickly switch between different training modes, such as warm-up, endurance or strength mode, without interrupting the user's exercise flow.

[0144] In another alternative, the method can comprise the steps of providing an input signal to the control unit of the electromechanical resistance module, which sets the control unit to an automatic training mode, exerting a force through the user interface against the synthetic resistance source, causing the weight stack of the weight stack set to be lifted, reducing the force against the synthetic resistance source, causing the weight stack of the weight stack set to be lowered, and adjusting the second resistance source by the control unit.

[0145] The automatic training mode simplifies the user experience, allowing the fitness machine to autonomously adjust the resistance level based on a predetermined algorithm, optimizing the efficiency and effectiveness of the exercise without the need for continuous user intervention. The input signal can be provided by the user interface or an external device.

[0146] In another alternative, the user can use the electromechanical resistance module to fine-tune the physical weight, such as traditional iron weight stacks. For example, the user can select a 40 kg iron weight stack as the training weight and add an electrical resistance equivalent to 2 kg, resulting in a total weight of 42 kg, where the haptic feedback is mainly provided by the iron weight stack, while the electrical resistance is almost imperceptible. This fine-tuning to 42 kg is not possible on traditional strength machines, as iron weight stacks are usually incremented in 5 kg or 10 lb steps. This fine-tuning is particularly important to break through so-called plateaus, where the user needs a progressive small weight increase of 1 kg to 2 kg to reach a new performance level.

[0147] The person skilled in the art will recognize that the advantages, technical effects and preferred embodiments discussed in connection with the hybrid resistance generation system and the fitness machine equally apply to the method of adjusting a force that a user has to exert on the fitness machine. Likewise, all advantages, technical effects and preferred embodiments described in connection with the method also apply to the hybrid resistance generation system and the fitness machine.

[0148] Further examples of embodiments will be explained in greater detail below with reference to the accompanying drawings. The present application is not intended to be limited to only these listed examples of embodiments. They serve only to explain the present application in greater detail. The present application is intended to encompass all objects that will be obvious to a person skilled in the art now or in the future for implementing the present application. BRIEF DESCRIPTION OF DRAWINGS

[0149] Figure 1A perspective view of a preferred embodiment of a hybrid resistance generation system is shown.

[0150] Figure 2 A cross-section of a preferred embodiment of a hybrid resistance generation system with two chambers is shown.

[0151] Figure 3 A cross-section of a preferred embodiment of a hybrid resistance generation system with four chambers is shown.

[0152] Figure 4 A schematic of a preferred embodiment of a hybrid resistance generation system using a laser device as a sensor system is shown.

[0153] Figure 5 A flowchart of a method for adjusting the force applied by a user to a preferred exercise machine is shown.

[0154] Figure 6 A flowchart of another method for adjusting the force applied by a user to a preferred exercise machine is shown.

[0155] Figure 7 A flowchart of another method for adjusting the force applied by a user to a preferred exercise machine is shown.

[0156] Figure 8 A perspective view of a preferred embodiment of an exercise machine is shown.

[0157] Figure 9 A partial view of a preferred embodiment of an exercise machine, in particular two hybrid resistance generation systems, is shown.

[0158] Figure 10 A partial view of a preferred embodiment of an exercise machine, in particular two hybrid resistance generation systems, is shown.

[0159] Figure 11 A perspective view of a preferred embodiment of a weight bar in connection with a second cable via an adapter is shown.

[0160] Figure 12 A front view of a preferred embodiment of a weight bar in connection with a second cable via an adapter is shown, as well as a detailed view focusing on the adapter area.

[0161] Figure 13 A side view of a preferred embodiment of a hybrid resistance generation system is shown, wherein a weight bar is connected with a second cable via an adapter, and further comprising a detailed view highlighting the adapter area.

[0162] Figure 14 A perspective view of a preferred embodiment of an exercise machine is shown. Figure 13A side view of a similar hybrid resistance generation system is configured, but with the housing in the closed position, and no cutaway portion to show internal components.

[0163] Figure 15 A hybrid resistance generation system is shown in perspective view from below, with at least half of the housing removed to fully expose the internal structure. All internal components and chambers of the system are visible in this view.

[0164] Figure 16 A front view is shown corresponding to an embodiment of Figure 11 , with the second cable no longer connected to the counterweight bar since the adapter has been detached.

[0165] Figure 17 A front view is shown corresponding to an embodiment of Figure 12 , with the second cable no longer connected to the counterweight bar since the adapter has been removed.

[0166] Figure 18 A side view is shown corresponding to an embodiment of Figure 13 , with the second cable disconnected from the counterweight bar, and the adapter no longer engaged.

[0167] Figure 19 A perspective view is shown corresponding to an embodiment of Figure 15 , with half of the housing removed to expose internal components, and the second cable no longer connected to the counterweight bar.

[0168] Figure 20 An external view is shown of the adapter in a connected state with the counterweight bar Figure 20 a) and the corresponding cross-sectional view Figure 20 b).

[0169] Figure 21 An enlarged detail of the cross-sectional area shown in Figure 20 b is shown, highlighting the connection mechanism between the adapter and the counterweight bar in the connected state.

[0170] Figure 22 An external view is shown of the adapter in a disconnected state, with the second cable and the adapter disconnected from the counterweight bar.

[0171] Figure 23 An external view is shown of the adapter in a disconnected state, with the second cable and the adapter disconnected from the counterweight bar. DETAILED DESCRIPTION

[0172] Certain portions of the embodiments have similar or identical components. Similar or identical components can have the same name and / or reference number. Where appropriate, a description of one component can apply by reference to another similar component, reducing text duplication without limiting the disclosure. DETAILED DESCRIPTION

[0172] Certain portions of the embodiments have similar or identical components. Similar or identical components can have the same name and / or reference number. Where appropriate, a description of one component can apply by reference to another similar component, reducing text duplication without limiting the disclosure.

[0173] Figure 1 A preferred embodiment of the hybrid resistance generation system 63 is shown in perspective view. The hybrid resistance generation system 63 is preferably intended for use in the fitness machine 1.

[0174] The hybrid resistance generation system 63 comprises the sensor system 35, the weight stack 5 and the electromechanical resistance module 7. All components of the hybrid resistance generation system 63 are encapsulated in a housing 64.

[0175] The hybrid resistance generation system 63 is preferably integrated into the fitness machine 1 in such a way that the weight stack 5 is located between the two bar tubes 53 of the fitness machine 1 so that it can be guided vertically when the individual weight plates of the weight stack 5 are pulled up by the first cable 13. A user interface can be connected to the first cable 13 so that the user can exert a force on the first cable 13. The upper side of the housing 64 has openings through which the two bar tubes 53 of the fitness machine 1 are inserted into the housing 64 so that the bar tubes 53 of the fitness machine 1 can interact with the weight stack 5.

[0176] The housing 64 has openings 70, for example, for observing the movement of the individual components, such as the weight plates of the weight stack 5, during the exercise. In addition, the openings 70 can be used to provide an air inlet for cooling the electromechanical resistance module 7.

[0177] In addition, the hybrid resistance generation system 63 can also comprise a display 67. This display can be an LCD display, which is preferably located on a side wall or on the front of the housing 64 so that the user can see it during the exercise. The display 67 can display data processed by the control unit of the sensor system 35, an external device or the electromechanical resistance module 7, such as the weight measurement of the weight stack 5 in kilograms or pounds, the resistance measurement of the electromechanical resistance module 7 or the number of repetitions completed by the user in one exercise.

[0178] Figure 2 A cross-section of a preferred embodiment of the hybrid resistance generation system 63 with two chambers 65 is shown. In this figure, the front side of the housing 64 has been virtually removed so that the interior of the housing 64 can be seen.

[0179] The weight stack 5 comprises a plurality of weight blocks that can be connected to the weight bar 43. The weight stack 5 provides a first resistance source, while the electromechanical resistance module 7 provides a second resistance source. The two resistance sources are connected in series so that the resulting resistance source acts on the first cable 13.

[0180] The first cable 13 is connected to the weight bar 43, in particular to the plate 50 of the weight bar 43. The plate 50 of the weight bar 43 as well as all weight plates of the weight stack 5 have through-holes 56 to guide the bar tubes 53 of the fitness machine 1.

[0181] Furthermore, the weight bar 43 has an axially spaced-apart opening with a shaft 55, which is connected at its end to the second cable 14. The shaft 55 is used, among other things, to connect the weight of the weight stack 5 to the weight bar 43 by means of the pin 18 (not shown in Figure 1 、 Figure 2 or Figure 3 the second cable 14.

[0182] The second cable 14 is used to connect the electromechanical resistance module 7 and the weight bar 43, so that the resistance generated by the weight stack 5 is connected in series with the resistance generated by the electromechanical resistance module 7.

[0183] In this regard, the weight stack 5 is located in a first chamber 65, and the electromechanical resistance module 7 is located in a second chamber 65, wherein the second chamber 65 is located below the first chamber 65. Two pulleys 66 guide the second cable 14 to the weight bar 43 of the weight stack 5.

[0184] The electromechanical resistance module 7 comprises an electric motor 31 with a capstan 33, on which the second cable 14 can be wound and unwound.

[0185] Furthermore, the sensor system 35 comprises a load cell 41. The load cell 41 is mounted directly on the plate 50 of the weight bar 43. The load cell 41 is connected to the end of the cable 13, which can be connected to a user interface, such as a handle, of the fitness machine 1. The load cell 41 can be screwed to the plate 50 of the weight bar 43, so that the load cell 41 is firmly fixed in the plate 50 and can measure the force acting between the cable 13 and the plate 50.

[0186] Figure 3 A cross section of a preferred embodiment of the hybrid resistance generation system 63 with four chambers is shown. Like Figure 2 the front of the housing 64 is (virtually) removed.

[0187] In this embodiment, the housing 64 is divided into four chambers 65. In this regard, the weight stack 5 is located in a first chamber 65. The components of the electromechanical resistance module 7 are divided into two further chambers 65. Thus, the electric motor 31 of the electromechanical resistance module 7 is located in a second chamber 65, and the capstan 33 of the electromechanical resistance module 7 is located in a third chamber 65.

[0188] In a fourth chamber 65 located in the upper left corner of the housing 64, a stand for a device such as a smartphone is provided. The housing 64 can have an opening 70 in the front at the location of the fourth chamber 65, through which the user can see the smartphone from the outside when it is inserted into the fourth chamber 65.

[0189] Figure 4Another preferred embodiment of the hybrid resistance generation system 63 is shown. This embodiment is depicted in a schematic cross-sectional view, showing the hybrid resistance generation system 63 from a side perspective.

[0190] The hybrid resistance generation system 63 comprises a laser device 68, wherein the laser device 68 is located below the lowermost weight plate of the weight stack 5 and is directed towards the pegs 18 of the weight stack 5. For example, the laser device 68 can be located in a cavity 65 below the cavity 65 of the weight stack 5.

[0191] The laser device 68 is configured to emit a laser beam 69 towards the pegs 18 and to analyze the reflection of the laser beam 69 on the pegs 18. The pegs 18 comprise a shaft and a plug. The laser beam 69 is directed specifically towards the plug, while the peg shaft is inserted into the weight stack 5 and connects the individual weight plates or weights with the weight bar 43.

[0192] In the initial position (a), each weight plate of the weight stack 5 has a predetermined distance to the laser device 68. A control unit, which controls the laser device 68, can assign a specific weight to these predetermined distances. This enables to determine how many weight plates are lifted.

[0193] For example, the third weight plate from the top in the weight stack 5 is at a distance x from the laser device 68 in the initial position (a). The laser device 68 knows from stored data that the peg 18 is inserted into the third weight plate of the weight stack 5 at a distance x. When it is lifted to the second position (b), the third weight plate is lifted to a distance y. Since each weight plate weighs 5 kg and the weight bar 43 weighs 2 kg, the control unit can determine that the user is lifting a real weight of 17 kg.

[0194] When the lifted weight plate is returned from position (b) to position (a) or approaches position (a), the laser device can determine that one repetition has been completed based on the distance x. In this way, it can count the number of repetitions.

[0195] It is also disclosed here that the laser device 68 can be used independently for a conventional weight stack 5 without the other components of the hybrid resistance generation system 63.

[0196] Figure 5is a flow chart illustrating a preferred method 1000 for adjusting the force a user has to exert on the fitness machine 1. At 1002, the method 1000 comprises exerting a force through the user interface against the combined resistance source. At 1004, it involves acquiring the motion of the weight plates of the weight stack 5, in particular the speed and / or acceleration of the motion, by the sensor system 35. At 1006, the method comprises providing the acquired data from the sensor system 35 to the control unit 34 of the electromechanical resistance module 7. At 1008, the control unit 34 detects a decrease in speed and / or acceleration relative to previous acquired data from the sensor system 35. At 1010, the control unit 34 adjusts the second resistance source.

[0197] Handling a large number of weight plates of the weight stack 5 can be risky. By distributing the load between the weight plates of the weight stack 5 and the electromechanical resistance module 7, digital safety measures can be implemented in order to gradually reduce or completely shut down the electromechanical resistance module 7 in case of a dangerous situation.

[0198] When the hybrid resistance generation system 63 detects that the user is tiring, the sensor system 35 and / or the control unit 34 of the electromechanical resistance module 7 can notice that the repetitive motion is slowing down and that the rest time between tiring is getting longer by measuring a slowing down of the motion to the three-axis accelerometer and will reduce the electromechanical resistance.

[0199] For example, a user can select a 40 kg weight stack 5 and an electromechanical resistance equivalent to 20 kg. If the user is tiring during the exercise, the sensor system 35 and / or the control unit 34 can detect this by noting that the speed at which the weight plates of the weight stack 5 are pushed / pulled is slowing down (typically at the end of a set of movements). The electromechanical resistance module 7 will then reduce the electromechanical resistance by 5 kg and subsequently by 1 kg in each subsequent repetition. This allows the user to continue the exercise without having to stop because of the weight being too heavy or tiring, which is not possible with traditional fitness machines comprising iron weight plates.

[0200] Figure 6 is a flow chart illustrating another preferred method 1000 for adjusting the force a user exerts on the preferred fitness machine 1. At 1002, the method 1000 comprises exerting a force through the user interface against the combined resistance source. At 1003, it involves providing an input signal to the control unit 34 through the user interface. At 1010, the method 1000 comprises adjusting the second resistance source by the control unit 34. This method 1000 allows the user to manually adjust and / or stop the resistance of the electromechanical resistance module 7 through the user interface. To this end, the user interface can comprise input means such as a rotary adjustment ring or a button.

[0201] Figure 7is a flowchart showing another method 1000 for adjusting the force applied by a user to the preferred exercise machine 1. At 1001, an input signal is provided to the control unit 34 of the electromechanical resistance module 7, setting the control unit 34 to an automatic training mode. At 1002, the user applies force through the user interface to counter the synthetic resistance source, causing the weight plates of the weight plate set 5 to be lifted. At 1005, the user reduces the force against the synthetic resistance source, causing the weight plates of the weight plate set 5 to be lowered. At 1010, the control unit 34 adjusts the second resistance source.

[0202] Comparing the described method 1000 to conventional training, the advantages of the preferred exercise machine 1 can be realized.

[0203] For high pulldown training on a conventional multi-functional rack without an electromechanical resistance module 7, the user can first select a warm-up weight, for example between 20 kg and 40 kg, depending on the strength and experience of the user. After the warm-up, the user can complete three sets of 12-15 repetitions with a physical weight of 60 kg.

[0204] During the exercise, the user has to get up from the seat each time the weight needs to be changed. This includes moving the thighs away from the thigh pads, getting off the bench, adjusting the weight with the weight pin. Then the user gets back on the bench and re-attaches the thighs to the pads. In the last repetitions of a set, as the fatigue increases, the user can have difficulty completing the set. If the weight could be reduced to 55 kg or 50 kg in the last repetitions of a set, they can have done 2-5 more repetitions, reaching maximum muscle tension. But with a conventional weight system, it is not possible to do this without interrupting the training for at least 10 seconds, including the time to reposition and manually change the weight.

[0205] As a result, the muscles do not reach their optimal performance state and the duration of tension is shorter than if the weight could be gradually reduced. In addition, it is not realistic to change the weight every 2-3 repetitions, it is too inefficient.

[0206] A preferred exercise machine 1, designed as a high pulldown machine on a multi-functional rack with an electromechanical resistance module 7, can start similarly to a conventional machine, with the user selecting a warm-up weight between 20 kg and 40 kg. The user can then select the desired training program on the electromechanical resistance module 7, here as a decreasing set, either by voice control or manually on the software application of an external device.

[0207] With the electromechanical resistance module 7, there is no need to change the weight of the weight stack 5 between training sets. For example, the electromechanical resistance module 7 can increase the electromechanical resistance to 70 kg equivalent at the beginning of the training, and then gradually decrease the weight in 1 kg increments as the user's fatigue is detected, ensuring the longest time for the muscle to be under tension. The user can sit on the seat throughout the training without interrupting the training to change the weight.

[0208] Most importantly, these electromechanical resistance adjustments can be made every 2-3 repetitions, while maintaining a 40 kg base of physical weight, ensuring perfect visual, auditory, and inertial feedback from the weight stack 5. In addition, if the user wishes to use a different weight setting than the module automatically adjusts, they can simply turn the rotary adjuster on the user interface with a single finger to manually adjust the electromechanical resistance at any time.

[0209] Another example of the method 1000 described above is as follows: the user can set the weight stack 5 to 40 kg for a high pull-down training. Depending on the program they have chosen (automatic training mode) (e.g. "normal mode" or "decreasing set mode"), the electromechanical resistance module 7 will increase the resistance equivalent to 1 kg each time the user pulls. This way, the resistance can gradually increase each time the user pulls, for example, starting at 40 kg and increasing in 1 kg increments to 55 kg, without the need to change the physical weight stack 5.

[0210] The electromechanical resistance module 7 can operate like a pyramid, gradually increasing and decreasing resistance within a set of movements.

[0211] The maximum tension mode aims to maximize muscle tension and engagement within a set of movements. The user selects an initial large physical weight 5, for example 50 kg. The electromechanical resistance module 7 can initially be set to zero. When the user starts a set of movements, the electromechanical resistance module 7 gradually increases the resistance equivalent to 2 kg (pyramid increase) each time the movement is repeated. This increase continues until the total weight reaches the user's one-rep maximum (the maximum weight that can be lifted in one repetition), which in this example is 90 kg. The electromechanical resistance module 7 can store the peak one-rep maximum, so it can remember past peak one-rep maximums and continue to build a pyramid of resistance changes until a new maximum is reached.

[0212] At the peak weight (90 kg), the user will experience maximum resistance for a short period of time, fully engaging the muscle. After reaching the peak, the electromechanical resistance module 7 will decrease the weight by 2 kg in each subsequent repetition. This decrease continues until the electromechanical resistance is zero, leaving only the 50 kg physical weight 5. This gradual increase and decrease of weight targets different muscle fibers, helping to promote muscle development in a comprehensive way.

[0213] Another example covered by the method 1000 is as follows: in a variable resistance mode equipped with the electromechanical resistance module 7, the resistance varies non-linearly within a single repetition. Unlike a progressive or linear variation where the resistance is incremented or decremented at a constant rate, this mode makes unpredictable dynamic adjustments to the resistance at different stages of the movement.

[0214] At the beginning of the repetition, the user sets the weight of the weight stack 5 at a comfortable level, for example 50 kg. As the single movement / repetition progresses, the electromechanical resistance module 7 detects the level of muscle engagement and adjusts the resistance accordingly. At the middle of the repetition, the resistance can increase or decrease sharply. The intensity and duration of these changes can be programmed to create a challenging environment for the muscle. Towards the end of the repetition, the resistance can gradually decrease or suddenly increase according to the pre-set program. This unpredictability ensures that the muscle is constantly adapting to changing resistance. The non-linear variation of resistance forces the muscle to react to different loads, increasing the degree of muscle activation. The unpredictability of resistance variation helps to avoid plateaus in training. The muscle must constantly adapt to new challenges, promoting continuous progress and growth. By varying the load throughout the repetition, the stress on joints and tendons can be minimized, reducing the risk of overuse injuries common in constant or linear resistance training.

[0215] A repetition refers to the number of times a user performs a specific exercise movement in a set, while a set refers to performing a specific number of exercise movements in succession without rest.

[0216] Figure 8 A preferred embodiment of the fitness machine 1 is shown in perspective view. The fitness machine 1 is designed as a squat rack, the main body 3 of which is composed of frame elements, among others. The fitness machine 1 comprises two hybrid resistance generation systems 63. These systems 63 are each located at the bottom of the main body 3, between two bar tubes 53 of the fitness machine 1, which serve to guide the weight stack 5 of the hybrid resistance generation system 63. Each hybrid resistance generation system 63 is connected to the first cable 13.

[0217] In addition, the fitness machine 1 has pulleys 19 attached to the main body 3, which guide the first cable 13 to a user interface, at which the user can exert force against the resulting resistance. The user interface attached to the first cable 13 is not shown in the figures.

[0218] Figure 9 and Figure 10 Partial views of the preferred embodiment of the fitness machine 1 are shown, in particular of the two hybrid resistance generation systems 63. Both figures are detailed parts of Figure 8 , so more background information can be found in the description of Figure 8 .

[0219] In particular, Figure 10 A view is shown in which the housing 64 of one of the hybrid resistance systems 63 is removed. Thereby the weight stack 5 and the electromechanical resistance module 7 are visible, both separated by an intermediate layer or wall.

[0220] Figure 11 A perspective view is shown of a preferred embodiment in which the weight bar 43 is in connection with the second cable 14 via an adapter 74. The weight bar 43 is designed as an elongated shaft 55 with axially spaced openings configured to selectively engage with the weights of the weight stack 5 (not shown in Figure 11 For this purpose, a locking pin 18 (also not shown in Figure 11 ) can be passed through the openings of the weights of the weight stack 5 while inserted into one of the axial openings of the weight bar 43, thereby mechanically connecting the selected weights with the weight bar.

[0221] The second cable 14 is connected to a first end 71 of the weight bar 43, while the first cable 13 (not visible in Figure 11 ) is connected to a second end 73 of the weight bar. The first end 71 and the second end 73 are located on opposite sides with respect to the longitudinal axis of the weight bar 43. The first cable 13 is preferably guided through a pulley 75 mounted at the upper end 73 of the weight bar 43 in order to be able to exert a pulling force on the weight bar 43 during the exercise.

[0222] At the second end 73, the weight bar 43 can further comprise a plate 50 comprising two through-holes 56 configured to guide the bar tube 53 (not shown) of the fitness machine 1. The adapter 74 is used to detachably connect the second cable 14 to the weight bar 43 without the use of tools. In particular, the adapter 74 is configured to establish a detachable connection by means of a form- and / or force- locking connection mechanism.

[0223] In this regard, the adapter 74 is divided into parts with different functions. For example, a first part 77 is configured as a sleeve to receive the second cable 14 and to secure the cable by means of a clamping connection. A second part 79 of the adapter is configured to establish a detachable mechanical connection with the shaft portion 55 of the weight bar 43. This modular configuration allows for quick installation and disassembly of the electromechanical resistance module according to the desired training mode.

[0224] Figure 12 A front view is shown of a preferred embodiment in which the weight bar 43 is in connection with the second cable 14 via an adapter 74, as well as a detailed view focusing on the area of the adapter 74. In order to avoid repetition, reference is made to the Figure 11 described in Figure 11 .

[0225] The adapter 74 comprises two functional parts 77 and 79. The first part 77 is configured to receive the second cable 14 and to secure the cable's sleeve by a clamping connection. The second part 79 is configured to establish a detachable connection between the adapter 74 and the shaft 55 of the weight bar 43.

[0226] The clamping connection in the first part 77 is realized by three screws 81, each of which is screwed into a threaded hole in the sleeve's side wall. When tightened, the screws radially press the second cable 14, thereby securing it in the sleeve in a force-locking manner.

[0227] Figure 13 A side view of the preferred embodiment of the hybrid resistance generation system 63 is shown, wherein the weight bar 43 is connected to the second cable 14 by means of the adapter 74, and further comprises a detailed view highlighting the area of the adapter 74.

[0228] The hybrid resistance generation system 63 comprises a weight stack 5, which includes a plurality of individual weight plates that are selectively connectable to the weight bar 43, thereby forming a first resistance source. In addition, the hybrid resistance generation system 63 comprises an electromechanical resistance module 7 as a second resistance source. The electromechanical resistance module 7 comprises an electric motor 31 that is operably connected to a capstan 33, on which the second cable 14 can be wound and unwound.

[0229] The first and second resistance sources are arranged in series, wherein the second cable 14 interconnects the electromechanical resistance module 7 with the weight bar 43, such that the resulting combined resistance is transmitted to the first cable 13 (not shown in the middle) that is connected to the upper end 73 of the weight bar 43. The first cable interacts with a pulley 75 that is mounted at the upper end 73 and is capable of exerting a pulling force to the weight bar during operation. Figure 13

[0230] The system 63 further comprises a housing 64 with an internal compartment or chamber 65. In the shown view, the housing 64 is partially cut away to reveal the internal structure of the hybrid resistance generation system 63. Two pulleys 66 are provided below the lowermost weight plate of the weight stack 5, guiding the second cable 14 from the capstan 33 to the weight bar 43.

[0231] In this case, a retaining device is provided that is configured to retain the adapter 74 in a defined position relative to the capstan 33 when the adapter 74 is detached from the weight bar 43, to prevent the adapter 74 from falling to the ground. To this end, the housing 64 or frame of the hybrid resistance generation system 63 comprises a retaining plate 83 that is approximately parallel to the weight plates of the weight stack 5 and is arranged below the lowermost weight plate. The retaining plate 83 comprises a through-hole through which the second cable 14 passes. The adapter 74 is dimensioned such that it cannot pass through the through-hole, thereby forming a mechanical stop that retains the adapter when it is disconnected from the weight bar 43. ​

[0232] Figure 14 A side view of a similar hybrid resistance generation system 63 is shown, but the housing 64 is in the closed state and there is no cutaway to show the internal components. Figure 13

[0233] Figure 15 A hybrid resistance generation system 63 is shown in perspective view from below, with at least half of the housing 64 removed to fully expose the internal structure. In this view, all internal components and chambers 65 of the system 63 are visible.

[0234] Figures 16 to 19 Corresponding to Figure 11 , Figure 12 , Figure 13 and Figure 15 respectively in form and perspective. The difference is that in Figures 16 to 19 , the second cable 14 is no longer connected to the weight bar 43, since the adapter 74 has been detached.

[0235] Figures 20 to 23 The adapter 74 is shown in detail. Figure 20 a shows an external view of the adapter 74, Figure 20 b provides a corresponding cross-sectional view. Figure 21 An enlarged detail of the cross-sectional area shown in Figure 20 b is presented.

[0236] Figure 20 a, Figure 20 b and Figure 21 show the connected state, in which the adapter 74 is connected to the weight bar 43. In contrast, Figure 22 and Figure 23 depict the detached state, in which the adapter 74 is detached from the weight bar 43 together with the second cable. Since the adapter has already been described in the previous figures, reference can be made to the corresponding earlier descriptions.

[0237] The second part 79 of the adapter 74 is configured as a quick-release coupling, which contains an automatic locking mechanism that engages when the adapter 74 is pushed onto the corresponding connection structure of the weight bar 43. In addition, the quick-release coupling includes a manually actuated release element that allows tool-free disconnection of the adapter 74 only when intentionally actuated and prevents accidental release due to pulling forces acting on the second cable 14.

[0238] ​The quick release coupling comprises an adapter core 85 connected to the sleeve 87 of the first part 77, and an outer sleeve 89 surrounding the core 85 and axially movable against the spring force. Locking balls 91 are fixed in place by the outer sleeve 89 and automatically engage the circumferential groove on the weight bar 43 upon connection. To release the connection, the outer sleeve 89 can be manually retracted against the spring force. This construction ensures that pulling on the second cable 14 does not result in an unintentional uncoupling of the coupling.

[0239] The circumferential groove on the weight bar 43 can be implemented in different ways. In one variant, the shaft 55 of the weight bar 43 comprises a central axial bore at its first end 71 into which a groove-bearing protrusion 93 is inserted and fixed, for example by a press fit or a threaded connection. Alternatively, the groove or the entire protrusion 93 can be machined directly into the shaft 55, forming an integral part of the weight bar 43.

[0240] In other words, the quick release coupling can also be described as follows: The adapter 74 mechanism works like a quick coupling for pressurized air hoses, but is specifically adapted to solid mechanical load transfer. On the weight bar 43 side, the protrusion 93 comprises a metal pin with a threaded end and a mushroom head. This head is inserted into the spring-loaded quick release coupling of the adapter 74, which comprises a set of small locking balls 91 fixed in place by a sliding outer ring 89 (or sleeve 89).

[0241] When the ring 89 is pulled back, the spring is compressed and the balls 91 are released, allowing the mushroom head to enter the socket. Then, when the release ring 78 is released, the spring pushes it forward again, causing the balls 91 to lock into the groove behind the mushroom head. This mechanism reliably prevents unintentional uncoupling under load.

[0242] The above-described embodiments in this application can also be described using the following sub-lists.

[0243] The items of the first sub-list can be combined with one or more items of all other sub-lists herein and one or more features of the claims.

[0244] First sub-list:

[0245] 1. A hybrid resistance generation system 63 for a fitness machine, comprising:

[0246] - a housing 64, preferably comprising at least two chambers 65;

[0247] - a sensor system 35;

[0248] - a weight stack 5 with a plurality of weight plates connectable with a weight bar 43, providing a first resistance source;

[0249] - an electromechanical resistance module 7, providing a second resistance source;

[0250] wherein the first and the second resistance source are connected in series, such that the resulting resistance source acts on the first cable

[0251] 13. The first cable is preferably connected to the weight bar 43.

[0252] 2. The hybrid resistance generation system 63 according to item 1, characterized in that a second cable 14 interconnects the electromechanical resistance module 7 and the weight bar 43.

[0253] 3. The hybrid resistance generation system 63 according to item 1 or item 2, characterized in that the weight block set 5 is located in a first chamber 65 and the electromechanical resistance module 7 is located in a second chamber 65.

[0254] 4. The hybrid resistance generation system 63 according to any of the preceding items, characterized in that the hybrid resistance generation system 63 further comprises at least one pulley 66 guiding the second cable 14 to the weight bar 43 of the weight block set 5.

[0255] 5. The hybrid resistance generation system 63 according to any of the preceding items, characterized in that the electromechanical resistance module 7

[0256] comprises an electric motor 31 with a winch 33 on which the second cable 14 can be wound and unwound.

[0257] 6. The hybrid resistance generation system 63 according to item 5, characterized in that the electric motor 31 is designed as a brushless external rotor motor.

[0258] 7. The hybrid resistance generation system 63 according to item 5 or item 6, characterized in that the weight block set 5 is located in a first chamber 65 and the electric motor 31 is located in a second chamber 65 and the winch 33 is located in a third chamber 65.

[0259] 8. The hybrid resistance generation system 63 according to any of items 5 to 7, characterized in that the second chamber 65 and / or the third chamber 65 are located below the first chamber 65.

[0260] 9. The hybrid resistance generation system 63 according to any of the preceding items, characterized in that the electromechanical resistance module 7

[0261] comprises a control unit 34 having a data processing unit for controlling the second resistance source and a communication unit for data communication.

[0262] 10. The hybrid resistance generation system 63 according to any of the preceding items, characterized in that the sensor system 35 is configured to acquire the following:

[0263] - the resistance of the first resistance source and / or the resistance of the second resistance source and / or the resistance of the resulting resistance source and / or

[0264] or the movement of the weight stack 5 and / or the movement of the weight bar 43 and / or the movement of the first cable 13.

[0265] 11. The hybrid resistance generation system 63 according to any of the preceding items, characterized in that the sensor system 35 comprises a laser device 68, which is either located below the lowermost weight plate of the weight stack 5 or above the plate 50 of the weight bar 43 and is directed towards the peg 18 of the weight stack 5, the laser device 68 being configured to emit a laser beam 69 towards the peg 18 and to analyze the reflection of the laser beam 69 on the peg 18.

[0266] 12. The hybrid resistance generation system 63 according to any of the preceding items, characterized in that the hybrid resistance generation system 63 comprises at least one display 67, which can display data processed by the control unit 34 of the electromechanical resistance module and / or the control unit of the sensor system 35.

[0267]

[0268] 13. A fitness machine 1 comprising:

[0269] a. a main body 3;

[0270] b. a hybrid resistance generation system 63 according to any of the preceding items;

[0271] c. at least one pulley 19 attached to the main body 3, guiding the first cable 13 to a user interface for resisting the force applied by the synthetic resistance source, wherein the user interface is attached to the first cable 13.

[0272] 14. The fitness machine 1 according to item 13, characterized in that the electromechanical resistance module 7 and the sensor system 35 are in data communication with an external device having a data processing unit and a communication unit,

[0273] - wherein the sensor system 35 comprises means for providing the acquired data to the external device 45; and

[0274] / or

[0275] - wherein the user interface 11 comprises means for providing input signals to the external device 45; and

[0276] or

[0277] - wherein the external device 45 is configured to process the data provided by the sensor system 35 and / or the input data provided by the user interface and / or to transmit control commands to the electromechanical resistance module 7.

[0278] ​15. A method 1000 for adjusting the force a user has to exert on an exercise machine according to item 14, characterized in that the method comprises the steps of:

[0279] i. exerting a force against the synthetic resistance source by means of the user interface 11;

[0280] ii. acquiring the movement of the weight blocks of the weight block set 5, in particular the speed and / or acceleration of the movement, by means of the sensor system 35;

[0281] iii. providing the data acquired by the sensor system 35 to the control unit 34 of the electromechanical resistance module 7;

[0282] iv. detecting a decrease in speed and / or acceleration by means of the control unit 34 in relation to the data previously acquired by the sensor system 35;

[0283] v. adjusting the second resistance source by means of the control unit 34.

[0284] vi. and / or

[0285] vii. and / or

[0286] i. exerting a force against the synthetic resistance source by means of the user interface 11;

[0287] ii. providing an input signal to the control unit 34 by means of the user interface 11;

[0288] iii. adjusting the second resistance source by means of the control unit 34.

[0289] iv. and / or

[0290] i. providing an input signal to the control unit 34 of the electromechanical resistance module 7, which sets the control unit 34 to an automatic training mode;

[0291] ii. exerting a force against the synthetic resistance source by means of the user interface 11, so that the weight blocks of the weight block set 5 are lifted;

[0292] iii. reducing the force against the synthetic resistance source, so that the weight blocks of the weight block set 5 are lowered;

[0293] iv. adjusting the second resistance source by means of the control unit 34.

[0294] Second sub-list:

[0295] 1. A hybrid resistance generation system 63 for an exercise machine, comprising:

[0296] - a weight block set 5 with a plurality of weight blocks connectable with a weight bar 43, providing a first resistance source;

[0297] - an electromechanical resistance module 7 with a second resistance source;

[0298] - an electromechanical resistance module 7 providing a second resistance source, the electromechanical resistance module 7 comprising an electric motor 31 with a winch 33 on which the second cable 14 can be wound and unwound;

[0299] - wherein the first resistance source and the second resistance source are connected in series, the second cable 14 interconnecting the electromechanical resistance module 7 with the counterweight bar 43 such that the combined resistance source acts on the first cable 13 connected to the counterweight bar 43;

[0300] - wherein the second cable 14 is connected to a first end of the counterweight bar 43 and the first cable is connected to a second end of the counterweight bar 43, the first end and the second end being located on opposite sides of the counterweight bar 43;

[0301] characterized in that

[0302] - two pulleys 66 guide the second cable 14 from the electromechanical resistance module 7 to the second end of the counterweight bar 43 of the counterweight block group 5.

[0303] 2. Hybrid resistance generation system 63 according to item 1, wherein the two pulleys 66 are arranged in such a way that, regardless of whether the counterweight bar 43 is moving upwards, downwards or is in a stationary position, the pulleys 66 and / or the second cable 14 are always located below the second end of the counterweight bar 43 relative to the ground.

[0304] 3. Hybrid resistance generation system 63 according to item 1, wherein the hybrid resistance generation system 63 comprises a housing 64.

[0305] 4. Hybrid resistance generation system 63 according to item 3, wherein the housing 64 comprises at least two chambers 65.

[0306] 5. Hybrid resistance generation system 63 according to item 4, wherein the counterweight block group 5 is located in a first chamber 65 and the electromechanical resistance module 7 is located in a second chamber 65, the second chamber 65 being located below the first chamber 65.

[0307] 6. Hybrid resistance generation system 63 according to item 4, wherein the counterweight block group 5 is located in a first chamber 65, the electric motor 31 is located in a second chamber 65 and the winch 33 is located in a third chamber 65.

[0308] 7. Hybrid resistance generation system 63 according to any of the preceding items, wherein the electric motor 31 is designed as a brushless external rotor motor.

[0309] 8. Hybrid resistance generation system 63 according to any of the preceding items, wherein the electromechanical resistance module 7 comprises a control unit 34 having a data processing unit for controlling the second resistance source and a communication unit for data communication.

[0310] 9. Hybrid resistance generation system 63 according to any of the preceding items, wherein the hybrid resistance generation system 63 comprises a sensor system 35 configured to acquire:

[0311] - the resistance of the first resistance source and / or the resistance of the second resistance source and / or the resistance of the composite resistance source and / or

[0312] or the movement of the weight stack 5 and / or the movement of the weight rod 43 and / or the movement of the first cable 13.

[0313] 10. Hybrid resistance generation system 63 according to item 9, wherein the sensor system 35 comprises a laser device 68 either positioned below the lowermost weight plate of the weight stack 5 or above the plate 50 of the weight rod 43 and directed towards the peg 18 of the weight stack 5, the laser device 68 being configured to emit a laser beam 69 towards the peg 18 and to analyze the reflection of the laser beam 69 on the peg 18.

[0314] 11. Hybrid resistance generation system 63 according to any of the preceding items, wherein the hybrid resistance generation system 63 comprises at least one display 67 which can display data processed by the control unit 34 of the electromechanical resistance module and / or

[0315] or the control unit of the sensor system 35.

[0316] 12. Hybrid resistance generation system 63 according to any of the preceding items, wherein the hybrid resistance generation system 63 comprises an adapter 74 allowing the detachable connection of the second cable 14 to the weight rod 43 without the use of tools.

[0317] 13. Fitness machine 1 comprising:

[0318] a. a main body 3;

[0319] b. a hybrid resistance generation system 63 according to any of the preceding items;

[0320] c. at least one pulley 19 attached to the main body 13 guiding the first cable 13 to a user interface 11 for exerting force against the composite resistance source, wherein the user interface is attached to the first cable 13.

[0321] 14. Fitness machine 1 according to item 13, wherein the electromechanical resistance module 7 and the sensor system 35 are in data communication with an external device having a data processing unit and a communication unit,

[0322] - wherein the sensor system 35 comprises means for providing the acquired data to the external device 45; and

[0323] or

[0324] - wherein the user interface 11 comprises means for providing input signals to the external device 45; and

[0325] or

[0326] - wherein the external device 45 is configured to process data provided by the sensor system 35 and / or input data provided by the user interface and / or to transmit control commands to the electromechanical resistance module 7.

[0327] 15. A method 1000 for adjusting the force a user has to apply to the fitness machine according to item 14, the method 1000 comprising the steps of:

[0328] i. applying a force by means of the user interface 11 against the synthetic resistance source;

[0329] ii. acquiring the movement of the weight stack of the weight stack group 5, in particular the speed and / or acceleration of the movement, by means of the sensor system 35;

[0330] iii. providing the data acquired by the sensor system 35 to the control unit 34 of the electromechanical resistance module 7;

[0331] iv. detecting a decrease in speed and / or acceleration by means of the control unit 34 in relation to the data previously acquired by the sensor system 35;

[0332] v. adjusting the second resistance source by means of the control unit 34.

[0333] vi. providing the data acquired by the sensor system 35 to the control unit 34 of the electromechanical resistance module 7.

[0334] 16. A method 1000 for adjusting the force a user has to apply to the fitness machine according to item 14, the method 1000 comprising the steps of:

[0335] i. applying a force by means of the user interface 11 against the synthetic resistance source;

[0336] ii. providing input signals to the control unit 34 by means of the user interface 11;

[0337] iii. adjusting the second resistance source by means of the control unit 34.

[0338] 17. A method 1000 for adjusting the force a user has to apply to the fitness machine according to item 14, the method comprising the steps of:

[0339] i. providing input signals to the control unit 34 of the electromechanical resistance module 7, the input signals setting the control unit 34 to an automatic training mode;

[0340] ii. adjusting the second resistance source by means of the control unit 34.

[0341] ii. exert a force through the user interface 11 against the synthetic resistance source, causing the weight blocks of the weight block set 5 to be lifted;

[0342] iii. reduce the force against the synthetic resistance source, causing the weight blocks of the weight block set 5 to be lowered;

[0343] iv. adjust the second resistance source by the control unit 34.

[0344] List of reference signs

[0345] 1 exercise machine

[0346] 3 main body

[0347] 5 physical weight block | weight block set

[0348] 7 electromechanical resistance module

[0349] 13 first cable

[0350] 14 second cable

[0351] 18 peg

[0352] 19 pulley

[0353] 31 electric motor

[0354] 33 capstan

[0355] 34 control unit

[0356] 35 sensor system

[0357] 41 load cell

[0358] 42 triaxial accelerometer

[0359] 43 weight bar

[0360] 44 battery

[0361] 50 plate

[0362] 53 rod tube of the exercise machine

[0363] 55 shaft with axially spaced openings

[0364] 56 through hole for guiding the rod tube of the exercise machine

[0365] 63 hybrid resistance generation system

[0366] 64 housing of the hybrid resistance generation system

[0367] 65 chamber within the housing

[0368] 66 pulley of the chamber system

[0369] 67 display

[0370] 68 laser device

[0371] 69 laser beam

[0372] 70 opening in the housing

[0373] 71 first end of the counterweight rod

[0374] 73 second end of the counterweight rod

[0375] 74 adapter

[0376] 75 pulley

[0377] 77 first part of the adapter

[0378] 79 second part of the adapter

[0379] 81 screw

[0380] 83 retaining plate

[0381] 85 adapter core

[0382] 87 sleeve in the first part of the adapter

[0383] 89 outer sleeve

[0384] 91 locking ball

[0385] 93 protrusion

Claims

1. Hybrid resistance generation system (63) for a fitness machine, comprising: - a weight stack (5) having a plurality of weight plates connectable to a weight bar (43) providing a first resistance source; - an electromechanical resistance module (7) providing a second resistance source, the electromechanical resistance module (7) comprising an electric motor (31) with a capstan (33) on which a second cable (14) can be wound and unwound; - wherein the first and second resistance sources are connected in series, the second cable (14) interconnecting the electromechanical resistance module (7) with the weight bar (43) such that a resultant resistance source acts on a first cable (13) connected to the weight bar (43); characterized in that - the hybrid resistance generation system (63) comprises a tool-free adapter (74) allowing the second cable (14) to be detachably connected to the weight bar (43).

2. The hybrid resistance generation system (63) of claim 1, wherein, The second cable (14) is connected to a first end (71) of the weight bar (43), and the first cable (13) is connected to a second end (73) of the weight bar (43), the first and second ends (71, 73) being located on opposite sides with respect to a longitudinal axis of the weight bar (43).

3. The hybrid resistance generation system (63) according to claim 1 or 2, wherein The adapter (74) is configured to detachably connect the second cable to the weight bar (43) by means of a form- and / or force-locking connection.

4. The hybrid resistance generation system (63) according to any one of the preceding claims, wherein, The adapter (74) is divided into parts (77, 79) with different functions, wherein a first part (77) is configured to receive the second cable (14) and to secure the cable by means of a clamping connection in a sleeve, and a second part (79) of the adapter is configured to establish a detachable connection between the adapter (74) and the weight bar (43).

5. The hybrid resistance generation system (63) of claim 4, wherein, The clamping connection is realized by means of at least one screw (81) which is screwed into a corresponding threaded hole in a side wall of the sleeve, thereby pressing and securing the second cable (14) inside the sleeve.

6. The hybrid resistance generation system (63) according to any one of claims 4 to 5, wherein, The second part (79) of the adapter (74) is configured as a quick-release coupling which comprises an automatic locking mechanism which engages when the adapter (74) is pushed onto a corresponding connection structure of the weight bar (43), and also comprises a manually actuated release element which only allows a tool-free disconnection of the adapter (74) when intentionally actuated.

7. The hybrid resistance generation system (63) of claim 6, wherein, The quick-release coupling comprises an adapter core which is connected to the sleeve of the first part (77), and an outer sleeve which surrounds the core and can be moved axially against the force of a spring, wherein a locking ball is fixed in place by the outer sleeve and automatically engages a groove on the weight bar (43) when connected, and the release of the connection requires the outer sleeve to be manually retracted, so that pulling on the second cable (14) does not result in an unintentional disconnection.

8. The hybrid resistance generation system (63) of claim 7, wherein, The groove on the weight bar (43) is provided by a separate protrusion (93) which is inserted into an axial hole in the first end (71) of the weight bar (43) and is fixed in the hole by means of a press fit, adhesive bonding or a threaded connection.

9. The hybrid resistance generation system (63) according to any one of claims 1 to 6, wherein, The adapter (74) comprises a rotatable locking nut which is mounted on a fixed adapter body and is threadedly connected to a mating thread on the weight bar (43), so that the second cable (14) can be secured to the weight bar (43) by simply rotating the locking nut, while the adapter body remains non-rotatable with respect to the cable.

10. The hybrid resistance generation system (63) according to any one of claims 1 to 6, wherein, The adapter (74) is configured to be detachably connected to the weight bar (43) by one of the following: (i) by a bayonet connection, wherein the adapter (74) is inserted onto a mating protrusion of the weight bar (43) and then rotated into a locked position; or (ii) by a pin connection, wherein a locking pin is inserted into aligned openings in the adapter (74) and the weight bar (43) to secure the connection.

11. The hybrid resistance generation system (63) according to any of the preceding claims, further comprising a holding device configured to hold the adapter (74) in a defined position relative to the winch (33) when the adapter (74) is detached from the weight bar (43) to prevent the adapter (74) from falling to the ground.

12. The hybrid resistance generation system (63) according to any one of the preceding claims, wherein, The housing or frame of the hybrid resistance generation system (63) comprises a holding plate (83) which is generally aligned with the weight plates of the weight stack (5) such that the holding plate (83) extends in a plane which is substantially parallel to a plane defined by the weight plates of the weight stack (5) and is arranged below the lowermost weight plate, the holding plate (83) comprising a through hole through which the second cable (14) passes and the adapter (74) is dimensioned such that it cannot pass through the through hole, thereby forming a mechanical stop which holds the adapter (74) when it is separated from the weight bar (43).

13. The hybrid resistance generation system (63) according to any one of the preceding claims, wherein, The adapter (74) is made of a material selected from the group consisting of aluminum, stainless steel, reinforced polymers and fiber-reinforced composites.

14. The hybrid resistance generation system (63) according to any one of the preceding claims, wherein, The adapter (74) comprises a locking indication element, such as a colored marking, a positioning notch or a mechanical stop, which is configured to provide a visual or tactile indication of the correct locked position of the adapter (74) relative to the weight bar (43).

15. A method of separating the adapter (74) from the weight bar (43) in the hybrid resistance generation system (63) according to any of the preceding claims, the method comprising: - manually releasing the locking element of the adapter (74) without the use of tools; - disengaging the adapter (74) from the shaft portion or connection structure of the weight bar (43); - separating the second cable (14) from the adapter (74), thereby separating the electromechanical resistance module (7) from the weight bar (43).

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