Footrest device, vehicle seat and motor vehicle

Abstract

The invention relates to a footrest device (10) for a vehicle seat (12) of a motor vehicle (14) with a support body (16) that is rotatable by an actuator (18) between a non-use position and a use position about an axis (20) and that this axis is mounted on a fastening element (22), wherein the support body (16) is held on the axis (20) and / or the axis (20) is held on the fastening element (22) by means of an overload clutch (24) which is designed to decouple when a predetermined force acting on the support body (16) in the use position is exceeded, in order to allow actuator-free rotation of the support body (16) about the axis (20). The invention further relates to a vehicle seat (12) and a motor vehicle (14).

Description

The invention relates to a footrest device for a vehicle seat of a motor vehicle according to claim 1. Furthermore, the invention relates to a vehicle seat of a motor vehicle and a corresponding motor vehicle according to claims 6 and 8. Motor vehicles can be equipped with footrests, attached to a front seat, to provide extra comfort for rear passengers. Depending on their position on the seat and in relation to a passenger's foot, these footrests primarily support the sole and / or heel of the foot, promoting a comfortable sitting or reclining position. Modern footrests typically feature a single-axis pivot mechanism, as this is simple to implement. DE 10 2018 204 987 A1 discloses an adjustment device with an adjustable footrest for a vehicle seat, wherein a drive unit is provided for generating an adjustment force for adjusting the footrest. DE 10 2025 101 732 B3 discloses a footrest for a vehicle seat, comprising a foot pad which is movable from a non-use position to a use position, wherein the foot pad is movable during the movement from the non-use position to the use position, wherein an electric motor is provided for driving the foot pad, wherein the foot pad has the electric motor centrally located on an underside, the electric motor is to radially drive a transmission rod and the foot pad is held on the underside by means of a receptacle, wherein the transmission rod passes through the receptacle without force, wherein the transmission rod engages at its end in a transmission mechanism, wherein the transmission mechanism is statically connected on one side to a vehicle seat connection and dynamically connected on the other side to an overload protection device, wherein the transmission rod passes through the overload protection device without force.wherein the overload protection is force-transmittingly connected to the mounting of the footrest, wherein in an overload case the force-transmitting connection of the overload protection is decoupled from the gearbox to the mounting. DE 102 09 184 B4 discloses a vehicle seat, preferably a vehicle rest seat, with a seat cushion and a lower leg support pivotably attached to the seat cushion, which is infinitely movable between a storage position and a use position and can be fixed in a freely selectable position, characterized in that the inclination of the lower leg support is automatically adjustable and the lower leg support has an overload protection which releases the fixation of the lower leg support in the event of an overload on both sides, so that it gives way in the event of an overload. DE 10 2023 120 222 A1 discloses a calf support for a vehicle seat, consisting of a lower leg support and a seat surface connection, wherein the lower leg support is pivotably attached to the seat surface connection, wherein the lower leg support is extendable, an overload protection device is provided, wherein the lower leg support can be decoupled from the seat surface connection by means of the overload protection device, and wherein a transmission tube is arranged in a rotationally fixed position by means of the overload protection device and is rotatable in an overload position. DE 10 2018 204 987 A1 discloses an adjustment device for a vehicle seat, comprising an adjustable footrest, a drive unit with an adjustable drive element for generating an adjustment force for moving the footrest between a retracted position and at least one extended position, and a transmission device for translating an adjustment movement of the drive element into an adjustment movement of the footrest. The drive element includes a rotatable drive pinion, and the transmission device includes a linkage mechanism interacting with the drive pinion. One problem that can occur with single-axis pivot mechanisms is that when the support is moved from a non-use position to the use position, especially if it is jerked into position, a passenger or user may unintentionally push the support downwards with their full weight while, for example, stretching their body. This results in a particularly high torque in the single-axis pivot mechanism and its associated components, and can lead to damage, including permanent deformation of the vehicle seat frame. One solution would be to reinforce the seat frame, for example with a metal structure, but this would add weight, depending on the design, of up to 1.5 kilograms per vehicle seat in a passenger car. The object of the present invention is therefore to provide a footrest device, a vehicle seat and a motor vehicle which, in a particularly advantageous manner, prevents damage to the motor vehicle in the event of an overload of a footrest by a weight force, and in which a particularly weight-saving design can be achieved. This problem is solved according to the invention by the subject matter of the independent claims. Advantageous embodiments and further developments of the invention are specified in the dependent claims, as well as in the description and in the drawings. A first aspect of the invention relates to a footrest device for a vehicle seat of a motor vehicle. The footrest device comprises a support body which, particularly in its operating position, serves to support the feet, specifically the soles and / or heels of a user or passenger of the motor vehicle, depending on the position. The vehicle seat can, in particular, be a front seat of the motor vehicle, to which the footrest device is attached in the mounted state. The support body of the footrest device according to the invention is rotatable or displaceable between a non-use position and, in particular, at least one, use position about an axis, the support axis, by means of an actuator. The axis is mounted on a fastening element, which can, for example, be mounted on the vehicle seat. According to the invention, the support body is held on the axis and / or the axis is held on the fastening element by means of an overload clutch, which is designed to decouple or release when a predetermined force, in particular a weight force, acting on the support body in the use position is exceeded, in order to allow actuator-free rotation or pivoting of the support body about the axis. In other words, a spring-loaded coupling is implemented on the support axle, whereby the coupling can decouple, or is decoupled, under a certain load to prevent damage, while still providing sufficient force to support the resting feet, especially the heels of the user or passenger. Actuator-free means that the support body or support plate can be rotated around the axis without using the actuator, and furthermore, that the actuator can be completely decoupled from the support or rotation axis, i.e., the axis, in order to avoid, for example, damage to the actuator. This offers the advantage that an incorrect load, for example, when rotating the support body from its non-use position to its use position, caused by an inattentive user, would result in the support body being rotatable around its axis towards the non-use position due to the overload clutch. This allows decoupling from the actuator and / or the axis, enabling easy oscillation. Furthermore, the design of the overload clutch between the support body and the axis, or between the axis and the mounting element, offers the advantage of a particularly space-saving installation area, allowing, for example, a very narrow housing for the components of the footrest system to be implemented, such as in a vehicle seatback.Furthermore, the advantage arises that the weight increase, which would otherwise occur with the reinforcement of a frame structure, can be avoided with the foot support device according to the invention. According to the invention, the overload clutch is designed as a spring-loaded clutch and / or on the axle. In other words, the disconnection or decoupling of the overload clutch is achieved via a spring element, in particular a spring and the spring force contained within it. For example, tension in the spring can prevent decoupling, whereas if a force acting on the spring exceeds its spring force, the spring can be compressed to decouple the overload clutch. Additionally or alternatively, the overload clutch is designed on the axle. In other words, the support axle or pivot axis thus acts as a bearing or a fixing point to which the clutch is attached. Both the spring-loaded clutch and its possible design on the axle offer the advantage of enabling the design of a particularly lightweight overload clutch and thus a footrest device. According to the invention, a spring element is mounted on the axle and held between two sleeves movable along the axle or in the axial direction. In the operating position, the spring pushes the sleeves apart to hold the support body or to achieve its operating position. In other words, the coupling has a spring mounted on an axle, which is preferably profiled, and held between two sleeves, so that the spring fixes the sleeves in such a way that the operating position can be achieved. This offers the advantage that the mechanism underlying the overload coupling can be designed to be particularly simple. In a further advantageous embodiment of the invention, the axle is profiled with a cross-sectional profile, which in particular deviates from a circular shape, and the sleeves are coupled to the axle via this profile to enable the transmission of an adjusting torque. In other words, an inner shape or the inner recess of the sleeve is adapted to an outer shape of the axle so that the sleeves can move along with the axle when it is rotated, in order to transmit the adjusting torque required for a corresponding movement of the support body when adjusting between the non-use position and the use position. This results in the advantage of a particularly simple and / or weight-saving design of the footrest device. In an advantageous embodiment of the invention, the support body is held on the axis by means of two retaining elements, which are freely rotatable on the axis and which can be coupled to one of the sleeves by means of a toothed contour or toothing, or, in the case of a non-decoupled overload coupling, are interlocked with each other. In other words, a corresponding retaining element, in particular designed as a lever, is provided for each sleeve, which holds the support body or the support plate. Due to the toothing between the retaining element and the sleeve, one can move the other and vice versa, whereby overload protection is simultaneously achieved by the spring element pressing the teeth of the toothing of the retaining element and the sleeve against each other.When the support body, and thus the respective holding element, is subjected to a load, the teeth are subjected to force and, upon reaching a force greater than the spring force, can move against each other, thereby decoupling the overload clutch. This results in the advantage that the overload clutch can be designed to be particularly robust and, at the same time, significantly lighter. In a further advantageous embodiment of the invention, a pin is provided perpendicular to the axial direction, which secures the respective retaining element against movement along the axis or in the axial direction. The retaining element can, in particular, have a recess in which the pin can be guided. In other words, the levers can rotate freely on the axis, with the pins preventing lateral movement, thus allowing the spring element to lock the teeth. This offers the advantage that the retaining elements can be easily fixed along the axial direction and designed to be rotatable relative to the axis. In a further advantageous embodiment of the invention, the actuator comprises a spindle motor that is coupled to the axis by means of a pivot lever and / or the spindle motor is held on the mounting element. The spindle motor can form a spindle drive together with a spindle. The combination of the spindle drive with the axis or pivot axis thus enables a simple translational adjustment of a spindle of the spindle drive into a pivoting motion, for rotating the support body around the axis. The spindle can, in particular, be connected to or act upon the pivot lever. In other words, the spindle motor adjusts the lever attached to the axis, which results in a rotation of the support plate.Depending on the desired angle for the operating position and the position of the mounting element relative to the vehicle seat, the desired angle for the support elements can be easily adjusted. This offers the advantage of making the footrest particularly comfortable to operate and / or use by a single user. A second aspect of the invention relates to a vehicle seat of a motor vehicle with a footrest device according to the first aspect of the invention, wherein the fastening element of the footrest device is held on a base body, in particular a seat surface element, and / or a backrest of the vehicle seat, in particular an adjustable backrest. The vehicle seat in question is specifically a front seat for a motor vehicle, with the footrest attached to its rear for a rear passenger. Both the seat base and the backrest can each include a frame to which, for example, cushions for the seat surface and / or backrest are attached. The footrest's mounting device can be arranged and, in particular, held on this frame. With an adjustable backrest, the angle of use can be varied depending on how far it is pivoted forward in the vehicle's longitudinal direction in its intended position, allowing the footrest to also be used as a heel rest. Advantageous embodiments and further developments, as well as advantages of the first aspect of the invention, are to be regarded as advantageous embodiments and further developments, as well as advantages of the second aspect of the invention, and vice versa. In an advantageous embodiment of the invention, the backrest is movable and, depending on the position it assumes, the support elements are positioned as a footrest and / or heel support in the operating position. In other words, the rotation angle around the axis of the support element can be varied from the non-operating position to the operating position, for example, to adapt it to an angle at which the backrest is pivoted in the longitudinal direction of the vehicle. Furthermore, if the fastening element is mounted on the backrest itself, the support elements can be moved or varied by rotating the backrest, particularly in the operating position, thus providing different options for supporting the user's foot.This offers the advantage that the vehicle seat can be used particularly advantageously by a rear passenger to support their feet. A third aspect of the invention relates to a motor vehicle comprising a footrest device according to the first aspect of the invention and / or a vehicle seat according to the second aspect of the invention. Advantageous embodiments and further developments, as well as advantages of the first and second aspects of the invention, are to be regarded as advantageous embodiments and further developments, as well as advantages of the third aspect of the invention, and vice versa. Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention. It shows: Fig. 1 perspective detail view of a vehicle seat for a motor vehicle with a footrest device arranged on the vehicle seat in its mounting position on the backrest of the vehicle seat; Fig. 2 schematic side view of the vehicle seat with the footrest device, the support body of which is in a non-use position; Fig. 3 schematic side view of the vehicle seat according to Fig. 1 and Fig. 2, wherein the support body is in a use position; Fig. 4 schematic side view of the vehicle seat with footrest device, wherein the use position of the support body has varied due to a change in the backrest position of a vehicle seat backrest; Fig. 5 schematic perspective view of an axle of the footrest device on which an overload clutch is mounted, in the non-use position of the support body; Fig. 6 schematic perspective view of the axle according to Fig.5 in the operating position of the support body; and Fig. 7 schematic perspective view of the axis and the overload coupling, which is decoupled due to an overload. In the figures, identical or functionally equivalent elements are provided with the same reference symbols. Fig. 1 shows in a schematic perspective view a footrest device 10 which is mounted on a vehicle seat 12 and an associated motor vehicle 14, which is represented in the figures by the vehicle seat 12 and the footrest device 10. The motor vehicle 14 can be, in particular, a passenger car and / or a truck. The vehicle seat 12 is, in particular, a front seat. The footrest device 10 is therefore for a passenger or user of the motor vehicle 14 sitting in the rear and has a support body 16 for resting the feet. The foot support device 10 comprises the support body 16 which can be displaced, in particular rotated, about an axis 20 by an actuator 18 between a non-use position, which is shown in Fig. 1, and a use position, the possible variations of which are shown, for example, in Fig. 3 and Fig. 4. The axis 20 is mounted on a fastening element 22, which in the exemplary embodiment, for example, comprises the two angled components or angle elements shown in Fig. 1, which are attached to a backrest 26 of the vehicle seat 12. The support body 16 is held on the axis 20 and / or the axis 20 is held on the fastening element 22 by means of an overload clutch 24, which is designed to decouple the overload clutch 24 when a predetermined force 48 acting on the support body 16 is exceeded, and which is in particular a weight force accidentally induced by a user, in order to allow the support body 16 to pivot or rotate about the axis 20 without the need for an actuator. The overload coupling 24 is designed, in particular, as a spring-loaded coupling and, in the exemplary embodiment, is additionally mounted on the shaft 20. A spring element 28 is thus provided for the spring-loaded coupling, which is mounted on the shaft 20 and held between two sleeves 30 movable along the shaft 20. Conversely, in the operating position, but especially also in the non-operating position shown, the sleeves 30 are fixed along the shaft 20 relative to retaining elements 40 by the spring force of the spring element 28. Figures 2, 3 and 4 show the vehicle seat 12 with the footrest 10, each opposite a rear seat 32, with a leg or foot 34 of a passenger indicated. The foot 34 is shown specifically as a dummy foot. Fig. 2 shows a schematic side view of the motor vehicle 14 represented by the two seats, the vehicle seat 12, which is thus designed as the front seat, and the rear seat 32. Fig. 2 also shows the support body 16 of the footrest device 10 in its non-use position. Fig. 3 shows the support body 16 of the footrest device 10 unfolded or rotated about the axis 20 into the operating position by means of the actuator 18. The operating position assumed by the support body 16 in Fig. 3 due to the position of the backrest 26 is particularly advantageously designed to support a sole or toe of the foot 34. In contrast, Fig. 4 shows the support body 16, which moves with the backrest 26 due to a rotation of the backrest 26, in its operating position, in which the support body 16 serves in particular as a heel support, and it can also be seen that for a particularly comfortable quasi-reclining position the back seat 32 can have a corresponding thigh support in order to enable a particularly comfortable lying position for the user. The actuator 18 is almost a spindle drive or spindle motor, which is shown in Fig. 1, which is coupled to the axis 20 via a spindle by means of a pivot lever 38, wherein the spindle motor is held on the or an angle element of the fastening element 22. Fig. 5, Fig. 6 and Fig. 7 each show in a schematic perspective view the axis 20 and in particular the overload coupling 24 located on it, wherein the figures each describe a different state of the overload coupling 24, thereby illustrating its operation. Fig. 5 shows the axis 20 and thus the overload coupling 24 as it appears when the support body 16 is pivoted downwards in the non-use position, as can be seen in Fig. 5. As can be seen in Fig. 5, Fig. 6 and Fig. 7, the axis 20 has a cross-sectional profile or is profiled, wherein the two shells or sleeves 30 are coupled to the axis 20 via the cross-sectional profile and can thus rotate with it in order to enable the transmission of an adjusting torque or a force required for adjusting between the non-use position and the closed position. In Fig. 5, Fig. 6 and Fig. 7, a section through the right sleeve 30 and a section through the right retaining element 40 are shown in the upper right of each figure. The support body 16 is held on the axis 20 by means of two retaining elements 40, each designed as a lever, wherein the retaining elements 40 are freely rotatable with respect to the axis 20 and each can be coupled to one of the sleeves 30 by means of a toothed contour or a toothing 42, so that they interlock due to the force exerted on them by the spring element 28. In order to guide the support body 16 or the support plate advantageously, in addition to the retaining elements 40, two external guide elements 44 which are also freely rotatable about the axis 20 can be arranged. Fig. 6 shows the overload coupling 24, while the support body 16 (indicated by the position of the retaining elements 40 and the guide elements 44) is in the operating position, whereby the spring element 28, tensioned by the spring force, can ensure the meshing of the teeth 42 in the operating position. To prevent displacement of the retaining elements 40, as is possible for the sleeves 30 along the axial direction, pins 46 are advantageously provided which secure the respective retaining element 40 against movement along the axis 20, in particular by their respective arrangement in a recess of the respective retaining element 40. Fig. 7 shows the overload clutch 24 decoupled, whereby, due to a force of the user's weight, force 48, the teeth of the respective toothings 42 are displaced against each other, so that the spring force of the spring element 28 is no longer sufficient to hold the teeth together, thus compressing the spring element 28, so that the retaining elements 40 are no longer fixed relative to the axis 20 due to the guidance of the sleeves 30, but are rotatable, so that an actuator-free downward folding of the support body 16 is possible. In summary, the footrest device 10, the corresponding vehicle seat 12, and the motor vehicle 14 shown solve the problem of preventing damage to these items, which can occur when a large force 48 is suddenly and unexpectedly applied to the support body 16. This is achieved by the overload clutch 24 shown, which, together with the actuator 18, can be placed within a very narrow housing 50 on the backrest 26. The overload coupling 24, designed as a spring-loaded coupling, is implemented on the support axis, or axis 20, and can decouple under a certain load in order to prevent corresponding damage, while still providing enough force to support, for example, a stationary foot 34. The actuator 18 makes operating the footrest 10 particularly convenient. Furthermore, depending on the folded position of the backrest 26 and thus the front seat backrest of the vehicle seat 12, a desired angle can be adjusted to suit the needs of a rear passenger, as shown in Figures 3 and 4. As soon as the passenger unintentionally steps onto the support points or the support body 16 with their full weight, the latter rotates downwards. This only occurs under a defined load to prevent damage to, for example, the fastening element 22. The coupling has the spring element 28, which is mounted on the profiled axle 20 and held between two sleeves 30. The sleeves 30 can move laterally but are coupled to the cross-sectional profile of the axle 20 to allow the transmission of the adjusting torque. The two sleeves 30 are coupled by the toothed contour to two levers, the retaining elements 40, which form the crucial part of the support plate. The levers can rotate freely on the axle 20 and should not move laterally; they are therefore secured by the pins 46. In the event of overload, the force 48, which originates particularly from one or more feet 34, will push the levers downwards accordingly. As soon as a predetermined force 48 is reached, this leads to a lateral movement of the sleeves 30, which compresses the spring element 28. This releases the teeth, thereby decoupling the support plate from the axis 20 and causing it to rotate downwards. The support plate or support body 16 can be returned to its previous position by lifting it, for example by hand, until the overload clutch 24 or its toothing 42 engages automatically, and then it can be used normally again. Thus, a particularly advantageous footrest with overload protection is shown here in a particularly advantageous way.

Claims

Footrest device (10) for a vehicle seat (12) of a motor vehicle (14) with a support body (16) which is rotatable by an actuator (18) between a non-use position and a use position about an axis (20) and which is mounted on a fastening element (22), wherein the support body (16) is held on the axis (20) and / or the axis (20) is held on the fastening element (22) by means of an overload coupling (24) which is designed to decouple when a predetermined force acting on the support body (16) in the use position is exceeded in order to release actuator-free rotation of the support body (16) about the axis (20), wherein the overload coupling (24) is designed as a spring-loaded coupling and / or on the axis (20), characterized in that a spring element (28) is applied to the axis (20) and between two sleeves movable along the axis (20). (30) is heldwhich are pushed apart in the operating position by the spring element (28 spring). Foot support device (10) according to claim 1, characterized in that the axis (20) is profiled with a cross-sectional profile and the sleeves (30) are coupled to the axis (20) via this to enable the transmission of an adjusting torque. Foot support device (10) according to claim 2, characterized in that the support body (16) is held on the axis (20) by means of two retaining elements (40) which are freely rotatable on it and which can be coupled to one of the sleeves (30) via a toothing (42). Foot support device (10) according to claim 3, characterized in that a respective pin (46) perpendicular to the axis direction secures the respective retaining element (40) against movement along the axis (20). Foot support device (10) according to one of the preceding claims, characterized in that the actuator (18) comprises a spindle motor which is coupled to the axis (20) by means of a pivot lever (38) and / or the spindle motor is held on the fastening element (22). Vehicle seat (12) of a motor vehicle (14) with a footrest device (10) according to one of the preceding claims, the fastening element (22) of which is held on a base body and / or a backrest (26) of the vehicle seat (12). Vehicle seat (12) according to claim 6, characterized in that the backrest (26) is movable and, depending on a position assumed by it, the support body (16) is positioned in the operating position as a footrest. Motor vehicle (14) comprising a footrest device (10) according to one of claims 1 to 5 and / or a vehicle seat (12) according to claim 6 or 7.

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