Extendable calf support with pneumatic element for vehicle seat

Abstract

The invention relates to a vehicle seat with a calf support (3) rotatably mounted about a front edge of a seat cushion (1), wherein the calf support (3) has an extendable base structure (5) for reversible extension of the calf support (3) and an inflatable volume element (7), wherein the volume element (7) serves to be inflated when the calf support (3) is extended, and is designed to increase its volume while being guided by the base structure (5) during inflation, and in the inflated state, together with the base structure (5), to absorb a mechanical load generated by a person on the vehicle seat.

Description

[0001] The invention relates to a vehicle seat with a calf support rotatably mounted about a front edge of a seat cushion, and to a vehicle with such a vehicle seat.

[0002] A calf support on a vehicle seat, which is permanently or in one of several possible positions positioned between the front edge of the seat cushion and the vehicle floor, is limited in length, at least in that position, by the distance between the front edge of the seat cushion and the floor. Length-adjustable calf supports are known in the prior art, as is the attachment of a fold-out footplate to a lower leg support whose length can be adjusted by extension.

[0003] DE 102 09 186 A1 relates to a vehicle seat with a seat cushion and a lower leg support pivotably attached to the seat cushion, which is preferably automatically driven to move between a storage position and a use position, wherein the lower leg support has a footrest at its lower end, wherein the footrest has a footplate which is foldable about a pivot axis arranged transversely to the lower leg support and is arranged approximately parallel to the lower leg support in the storage position and approximately perpendicular to it in the use position, and wherein the footplate is connected to a power storage device and charges it when unfolded from the storage position to the use position.

[0004] DE 10 2018 106 404 A1 further relates to a seat assembly comprising: a backrest; and a seat functionally coupled to the backrest, comprising: a calf support rotatably coupled to the seat; a first bellows assembly arranged behind the calf support and configured to rotate the calf support approximately 90 degrees outwards from a design position to an operating position; an extension rotatably coupled to the calf support; and a second bellows assembly arranged between the calf support and the extension, configured to rotate the extension from a storage position to a support position.

[0005] However, under certain circumstances, the footrest on the lower leg support, as described in DE 102 09 186 A1, may lead to a reduction in comfort; should these prior art solutions also necessitate an excessive limitation of the length of the calf support, this will likewise lead to a reduction in comfort for an occupant in the vehicle seat.

[0006] The object of the invention is therefore to constructively improve a calf support of a vehicle seat and to design it for greater comfort.

[0007] The invention is defined by the features of the independent claims. Advantageous further developments and embodiments are the subject of the dependent claims.

[0008] A first aspect of the invention relates to a vehicle seat with a calf support rotatably mounted about a front edge of a seat cushion, wherein the calf support has an extendable base structure for reversible extension of the calf support and an inflatable volume element, wherein the volume element serves to be inflated when the calf support is extended, and is designed to increase its volume when inflated by being guided on the base structure, and in the inflated state, together with the base structure, to absorb a mechanical load generated by a person on the vehicle seat.

[0009] The vehicle seat is designed for a vehicle that must meet certain comfort requirements, for example, a passenger car with relatively high comfort features. This vehicle seat has a seat cushion and a seat back. The calf support is rotatably mounted at the front edge of the seat cushion, so that when the calf support is rotated from a stowed position to a horizontal plane, it comfortably supports the calves or lower legs of a passenger sitting in the vehicle, particularly below the front edge of the seat cushion.

[0010] The weight of the calves and lower legs, including the feet, as well as dynamic forces, are absorbed by the extendable base structure together with the inflatable volume element. This advantageously relieves the base structure, as the inflatable volume element, even in its inflated state, can not only distribute such loads across the base structure but can also bear loads itself.

[0011] Advantageously, the inflatable volume element incorporates an air-permeable spacer fabric within its interior, allowing it to be filled and pressurized with any gas, preferably air. Accordingly, it is essential to ensure the volume element is airtight to the outside so that it maintains a specific internal pressure for the expected duration of use of the calf support. This internal pressure can be adjusted by a pressure control unit, ensuring a constant target pressure within the volume element relative to the ambient pressure. Maintaining the target pressure within certain limits is crucial to ensure sufficient mechanical properties, particularly regarding the stiffness of the volume element, while simultaneously preventing excessive internal pressure that could lead to bursting or other damage.Preferably, the volume element extends in its width over the width of the basic structure, and in its length, when inflated, over the entire length of the basic structure in its extended state.

[0012] While various gases are suitable in principle for inflating the volume element, ambient air is preferably used, so that a pump for inflating the volume element can draw out the surrounding air without having to be connected to a dedicated gas tank. The pump is preferably located at the vehicle seat.

[0013] Although cushioning elements like this calf support typically use foam padding, the padding can be achieved, at least to a significant extent, by the inflatable volume element. Unlike foam, the volume element can be rolled flat or otherwise stored in a space-saving manner when deflated. The basic structure can also be collapsed, allowing the shortened calf support to fit into a small space. In its collapsed state, the calf support is shortened so that the limited distance between the front edge of the seat cushion and the floor does not hinder storage when the calf support is not in use. This advantageously results in a compact, telescopic calf support.

[0014] According to an advantageous embodiment, the inflatable volume element has a spacer fabric which is coated with an airtight film.

[0015] The spacer fabric can be designed as a spacer knit. The airtight film is preferably made of polyester and / or (thermoplastic) polyurethane and / or silicone. Furthermore, an opening is advantageously provided through at least one film coating the spacer fabric to allow a gas supply, in particular an air supply, to be directed into the interior of the volume element enclosed by the spacer fabric. This opening can alternatively also penetrate a weld seam that, for example, joins an upper film and a lower film around the spacer fabric. In addition, it is advantageous to provide an outlet, analogous to the opening, to allow the gas absorbed in the volume element to escape when the calf support is shortened, whereby the opening and the outlet can also be two functions in one and the same device.

[0016] According to a further advantageous embodiment, the base structure is coupled to an actuator, the actuator being configured to extend the base structure in response to a first control signal from a control unit and to retract the base structure in response to a second control signal. The respective control signal is transmitted, in particular, by an operating unit, so that the actuator can be activated at the command of the person seated in the vehicle to move the base structure and simultaneously and automatically adjust the filling state of the volume element for extending or shortening the calf support.

[0017] According to a further advantageous embodiment, the actuator is an electric actuator designed to extend or retract the base structure by means of its movement, and is coupled to a pump for inflating the volume element in such a way that, while the base structure is being extended by the actuator, gas is simultaneously and synchronously supplied by the pump to inflate the volume element. This advantageously achieves the synchronized extension of the base structure and the increase in volume within the volume element. This also ensures that the mechanical loads that can be applied by a person are distributed between the base structure and the volume element.

[0018] According to a further advantageous embodiment, the electric actuator is connected to a spindle drive and structural elements of the base structure moved by the spindle drive are mounted on guide rails.

[0019] According to a further advantageous embodiment, the spindle drive is connected to a scissor lift drive, wherein the scissor lift drive is connected to at least one of the structural elements in order to selectively extend or retract the basic structure.

[0020] The ratio of input distance to output distance is very good with a scissor lift drive in relation to the required installation space; other drive types can be used advantageously depending on the design conditions.

[0021] According to a further advantageous embodiment, the actuator is a pump designed to inflate the inflatable volume element in response to the first control signal and to extract or release gas from the inflated volume element in response to the second control signal, wherein the volume element is coupled to the base structure in such a way that a change in the volume of the volume element by inflating or removing gas causes a movement of the base structure, thus lengthening or shortening the calf support.

[0022] According to a further advantageous embodiment, the calf support has a retraction device designed to retract the volume element towards the vehicle seat while gas is continuously released from it after inflation.

[0023] According to a further advantageous embodiment, the retraction device comprises an actuator-driven cable pull unit. The cable pull unit serves to wind a cable connected to the volume element, particularly onto a pulley, by applying tension to the cable. This allows the volume element to be stowed during retraction of the base structure and stored compactly in the area of ​​the vehicle seat. Preferably, the cable pull unit comprises a motor coupled to a gearbox, which in turn drives the pulley at its output. By rotating the motor, the cable is wound onto the pulley, and the volume element is retracted with the wound cable while gas, particularly air, is released from the volume element. Preferably, the cable pull unit generates a tensile force of at least 200 N.

[0024] According to a further advantageous embodiment, the rotation of the calf support about an axis along the front edge of the seat cushion of the vehicle seat is mechanically and / or actuator-synchronized with the extension of the calf support.

[0025] This ensures that the required minimum angle is achieved by rotating the calf support away from the ground towards a horizontal position while extending the calf support, thus allowing for a certain degree of extension. Alternatively, both degrees of freedom can be adjusted independently of a person on the vehicle set; that is, they can change the angle to the horizontal and adjust the length of the calf support independently, in particular extending or shortening the calf support horizontally as desired.

[0026] According to another advantageous embodiment, the rotation of the calf support about an axis along the front edge of the seat cushion of the vehicle seat is driven by an actuator and is variable independently of the extension of the calf support.

[0027] Another aspect of the invention relates to a vehicle with a vehicle seat as described above and below.

[0028] Advantages and preferred further developments of the proposed vehicle result from an analogous and substantive transfer of the above statements made in connection with the proposed vehicle seat.

[0029] Further advantages, features, and details will become apparent from the following description, in which – possibly with reference to the drawing – at least one embodiment is described in detail. Identical, similar, and / or functionally equivalent parts are identified by the same reference numerals.

[0030] They show: Fig. 1: A vehicle seat with a calf support according to an embodiment of the invention. Fig. 2: A volume element on a vehicle seat according to an embodiment of the invention. Fig. 3: A basic structure of a calf support according to an embodiment of the invention. Fig. 4: A volume element according to an embodiment of the invention.

[0031] The representations in the figures are schematic and not to scale.

[0032] Fig. Figure 1 shows a vehicle seat from a side view, such as one that might be installed in the rear of a luxury passenger car. The vehicle seat has a seat back that can be adjusted to a reclining position and a seat cushion 1, and is equipped with a calf support 3 that is rotatably mounted about a front edge of the seat cushion 1. The calf support 3 can be rotated to a horizontal position and can be used in any angle from the folded-in position (i.e., extending downwards from the front edge of the seat cushion 1 and shortened in its longitudinal direction) to the horizontal. However, to reach the full length of the extendable calf support 3, a certain minimum angle of rotation from the fully retracted position on the seat cushion 1 towards the horizontal is required.To achieve its variable length, the calf support 3 comprises an extendable base structure 5 and an inflatable volume element 7, which are mechanically connected in such a way that while a reversible change in the length of the calf support 3 is possible, the volume element 7 and the base structure 5 also form a mechanically interacting layered structure to jointly distribute the load of the calves, lower legs, and feet of a person seated in the vehicle. Details of the volume element 7 are given in . Fig. 2 and Fig. 4 shows a possible implementation of the basic structure 5 is in Fig. Figure 3 shows that the basic structure 5 and the volume element 7 differ fundamentally in that the basic structure 5 has rigid parts that allow relative movement between them, while the volume element 7 is textile-like and deformable, making it inflatable. It can move along with the extension of the basic structure 5 and can be stored compactly when deflated by folding, rolling, or similar means. A control element for the person seated in the vehicle must be provided to adjust the angle and extension length of the calf support 3. This control element can be a wired or wireless remote control. For particularly high-quality interior designs, a textile covering can be used on the remote control's operating surface, for example, embroidered synthetic leather.Alternative control elements are of course possible, in particular designated control surfaces on a touch-sensitive display, mechanical remote controls with plastic buttons without fabric covering, etc.

[0033] Fig. Figure 2 shows a possible embodiment of the volume element 7. The volume element 7 can be increased by inflating it with air, but without this air, it can be flexibly rolled up within the volume element 7. For this purpose, a roller can be arranged in the seat cushion 1 so that when the volume element 7 is inflated, it simultaneously unrolls from the roller, acting as padding for the calf support 3. As the calf support 3 is deflated, the air is released from the volume element 7 and rewound onto the roller by a motor-assisted rotation of the roller. To assist with retraction, a pulley system can also be arranged to move the volume element 7 towards the seat cushion 1 and, for example, to be folded and stored under or inside the seat cushion 1, as an alternative to rolling it up on the roller.

[0034] Fig. Figure 3 shows an exemplary basic structure 5, arranged on a rigid base surface of the seat cushion 1. The basic structure 5 has several structural elements 17, which are shown in partial image (A) of the Fig. Figure 3 shows the extended position of the calf support 3. This extension is achieved by a controlled electric actuator 9, which includes an electric motor and a spindle drive 13 at the output of the electric motor. The spindle drive 13 sets the scissor lift drive 15 in motion and extends structural elements 17 one behind the other. By reversing the direction of movement of the electric motor, the basic structure 5 can be shortened, and the structural elements 17 are stacked on top of each other. The result is shown in partial figure (B) of the Fig. Figure 3 shows the structural elements 17 being mounted on guide rails. Advantageously, all moving parts should be lubricated, preferably with solid polymer lubricants, as these are more suitable in the textile environment (seat cushion 1, volume element 7) than oil, which may be chemically incompatible with the plastics used in the seat cushion 1 or volume element 7, can be odorous, and does not maintain lubrication for as long as polymer lubricants. Furthermore, volume element 7 is preferably attached to the foremost of the structural elements 17 with clamps to compensate for forces acting on volume element 7 when the calf support 3 is extended or shortened. The structural elements 17 are also designed as sheet metal bending parts that can be moved one above the other.If the volume element 7 and the structural elements 17 are extended synchronously to achieve an extension of the calf support 3 through both components, the sheet metal bending parts can be dimensioned accordingly smaller, since the volume element 7, with its internal air pressure, can withstand the mechanical load of a person. Preferred length changes from the first structural element 17 to the third structural element 17 are: 22 cm, 40 cm, 55 cm. In addition, rollers can be arranged on the base structure 5 to facilitate the movement of the volume element 7, particularly if the volume element 7 has additional layers and is designed to be especially robust and rigid.

[0035] Fig. Figure 4 shows a volume element 7 from above, but rotated 90° in the drawing plane to view the in Fig.The basic structure shown in Figure 3 comprises 5. Inside the volume element 7, spacer fabric is housed and surrounded by an airtight outer shell. For example, the spacer fabric has a nominal thickness of 30 mm. A pump 11 draws in ambient air to inflate air chambers of the volume element 7, which form a pneumatic cushion, to an air pressure of, for example, 0.4 bar relative to the ambient pressure when the calf support 3 is to be extended. A corresponding pressure control system with a pressure sensor for feedback of the actual state can be provided. The pump 11 is connected to one or more air chambers of the volume element 7 via a hose, for example, a PVC hose. Preferably, the hose is machine-welded to the volume element 7 to avoid failure-prone adhesive joints.For the spacer fabric, in particular thermoplastic polyurethane-coated or PVC-coated polyamide fabric in a woven structure is preferably used with 160 denier (unit denier) to prevent excessive crack propagation; optionally, a synthetic leather top layer can be applied as the top layer of the volume element 7 for interior design and to protect the volume element 7.

[0036] Although the invention has been illustrated and explained in detail by preferred embodiments, the invention is not limited by the disclosed examples, and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention. It is therefore clear that a multitude of variations exist. It is also clear that exemplary embodiments are truly only examples and should not be construed as limiting the scope, possible applications, or configuration of the invention in any way.Rather, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete terms, whereby the person skilled in the art, with knowledge of the disclosed inventive concept, can make various changes, for example with regard to the function or the arrangement of individual elements mentioned in an exemplary embodiment, without leaving the scope of protection defined by the claims and their legal equivalents, such as further explanations in the description. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 102 09 186 A1 [0003, 0005] DE 10 2018 106 404 A1

[0004]

Claims

[1] Vehicle seat with a calf support (3) rotatably mounted about a front edge of a seat cushion (1), wherein the calf support (3) has an extendable base structure (5) for the reversible extension of the calf support (3) and an inflatable volume element (7), wherein the volume element (7) serves to be inflated when the calf support (3) is extended and is designed to increase its volume when inflated along the extending base structure (5) in order to form a layered structure with the base structure (5) and, in the inflated state, to absorb a mechanical load generated by a person on the vehicle seat together with the base structure (5). [2] Vehicle seat according to claim 1, wherein the base structure (5) is coupled to an actuator (9), wherein the actuator (9) is designed to extend the base structure (5) in response to a first control signal from a control unit and to retract the base structure (5) in response to a second control signal. [3] Vehicle seat according to claim 2, wherein the actuator (9) is an electric actuator which is designed to extend or optionally retract the base structure (5) by its movement, and which is coupled to a control of a pump (11) in such a way that when the base structure (5) is extended by the actuator (9), gas is simultaneously pumped by the pump (11) to inflate the volume element (7). [4] Vehicle seat according to claim 3, wherein the electric actuator (9) is connected to a spindle drive (13) and structural elements (17) of the base structure (5) moved by the spindle drive (13) are mounted on guide rails. [5] Vehicle seat according to claim 4, wherein the spindle drive (13) is connected to a scissor lift drive (15), wherein the scissor lift drive (15) is connected to at least one of the structural elements (17) in order to selectively extend or retract the base structure (5). [6] Vehicle seat according to claim 2, wherein the actuator (9) is a pump (11) which is designed to inflate the inflatable volume element (7) in response to the first control signal and to remove or release gas from the inflated volume element (7) in response to the second control signal, wherein the volume element (7) is coupled to the base structure (5) in such a way that a change in the volume of the volume element (7) by inflating or removing gas causally causes a movement of the base structure (5) and thus lengthens or shortens the calf support (3). [7] Vehicle seat according to one of the preceding claims, wherein the calf support (3) has a retraction device which is designed to retract the volume element (7) towards the vehicle seat while gas is continuously released therefrom after inflation or after the gas has been completely released. [8] Vehicle seat according to one of claims 1 to 7, wherein the rotation of the calf support (3) about an axis along the front edge of the seat cushion (1) of the vehicle seat is mechanically and / or actuator-synchronized with the extension of the calf support (3). [9] Vehicle seat according to one of claims 1 to 7, wherein the rotation of the calf support (3) about an axis along the front edge of the seat cushion (1) of the vehicle seat is actuator-driven and is variable independently of the extension of the calf support (3). [10] Vehicle with a vehicle seat according to one of the preceding claims.

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