Patent Publication Number: US-2021178944-A1

Title: Vehicle seat with scissor frame arrangement

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of German Patent Application No. 102019134244.9 filed Dec. 13, 2019, the entire contents of which are incorporated herein by reference. 
     FIELD 
     The invention relates to a vehicle seat comprising a vehicle seat upper part and a vehicle seat lower part, which are spaced apart along a height axis Z and are connected to one another by means of a scissor frame arrangement, wherein the scissor frame arrangement comprises at least one inner swinging arm and at least one outer swinging arm. 
     BACKGROUND 
     Vehicle seats of this type are provided in particular in commercial vehicles such as tractors, construction machinery, forklifts, lorries, etc. In particular, driver&#39;s seats, in which the vehicle driver spends long periods of time, generally have to meet special conditions. The driver of the vehicle is exposed to physical stress due to the effects of vibrations caused by the state of the route. Such vibration effects should be reduced, among other things, by the driver&#39;s seat. 
     Corresponding vibration loads comprise vertical vibrations of the vehicle seat upper part along the height axis (Z), rotational vibrations due to a rolling movement of the vehicle seat upper part about the longitudinal axis (X), and rotational vibrations due to a pitching movement of the vehicle seat upper part about a width axis (Y). 
     SUMMARY 
     The object is achieved by a vehicle seat, comprising a vehicle seat upper part and a vehicle seat lower part, which are spaced apart from one another along a height axis (Z) and are connected to one another by means of a scissor frame arrangement, wherein the scissor frame arrangement comprises at least one inner swinging arm and at least one outer swinging arm, wherein the at least one inner swinging arm and the at least one outer swinging arm are mechanically coupled, whereby an angle of inclination (ξ) of the vehicle seat upper part relative to the vehicle seat lower part can be specified, wherein the mechanical coupling comprises an arm element and a first connecting element pivotably connected thereto, wherein the angle of inclination (ξ) can be specified by a length (L) of the first connecting element. 
     The angle of inclination can advantageously be the pitch angle. In the event of a pitching movement, the vehicle seat upper part tilts relative to the vehicle seat lower part about the width axis (Y). Likewise, the vehicle seat upper part can remain aligned horizontally during a pitching movement and the vehicle seat lower part can tilt about the width axis (Y) relative to the vehicle seat upper part. Due to the mechanical coupling according to the invention, the angle of inclination (ξ) or the pitch angle can be specified in an extremely simple manner. 
     The arm element is preferably arranged on the at least one inner swinging arm and the first connecting element is arranged on the at least one outer swinging arm. Alternatively, the arm element can be arranged on the at least one outer swinging arm and the first connecting element can be arranged on the at least one inner swinging arm. The arm element is preferably arranged on the at least one inner swinging arm or the at least one outer swinging arm so as to be rotatable about an axis of rotation. The first connecting element is preferably arranged on the at least one inner swinging arm or the at least one outer swinging arm so as to be rotatable about an axis of rotation. 
     Furthermore, it would be conceivable for the scissor frame arrangement to comprise a inner swinging arm pair and an outer swinging arm pair. It would also be conceivable that the arm element is arranged on both inner swinging arms or on only one inner swinging arm of the inner swinging arm pair. The arm element can also be arranged on both outer swinging arms or on only one outer swinging arm of the outer swinging arm pair. Similarly, the first connecting element can be arranged on both inner swinging arms or on only one inner swinging arm of the inner swinging arm pair, or on both outer swinging arms or on only one outer swinging arm of the outer swinging arm pair. 
     The arm element preferably extends along the longitudinal axis (X) and inclined downwards along the height axis (Z). With a horizontal orientation of the vehicle seat upper part, the arm element can preferably extend substantially parallel to a swinging arm. The arm element and the connecting element are preferably arranged in a substantially triangular shape. An angle μ preferably extends between the arm element and the connecting element, or between their central axes. The angle (μ) is dependent on the angle of inclination (ξ). The angle μ is preferably in a range between 10° and 90°. An angle of attack (λ) advantageously extends between the connecting element or a central axis of the connecting element and the vehicle seat lower part. If the inclination of the vehicle seat upper part changes, an angle of attack (λ) changes according to the inclination angle (ξ). The angle of attack (λ) is preferably in a range between 10° and 90°. 
     According to a preferred embodiment, the at least one inner swinging arm and the at least one outer swinging arm are connected by a second connecting element which can be rotated in each case about a first or a second axis of rotation extending along a width direction (Y) relative to the at least one inner swinging arm and relative to the at least one outer swinging arm. The at least one inner swinging arm and the at least one outer swinging arm preferably intersect in an intersection region. The first axis of rotation and the second axis of rotation are advantageously arranged, at least in a non-use position, along the height axis (Z) above the intersection region or along the height axis (Z) below the intersection region. Advantageously, at least in the non-use position, the connecting element is arranged substantially centrally with respect to a distance between the vehicle seat upper part and the vehicle seat lower part. Accordingly, it is preferred that the at least one inner swinging arm and the at least one outer swinging arm are designed in such a way that, at least in the non-use position, the intersection region is arranged eccentrically with respect to the distance between the vehicle seat upper part and the vehicle seat lower part. The first axis of rotation and the second axis of rotation have preferably a predetermined distance, at least in a non-use position, along the height axis (Z) to the vehicle seat lower part. This predetermined distance can advantageously be the same distance. Therefore, the connecting element would not be pivoted in the non-use position, whereby the two axes of rotation are arranged at the same height. However, it would also be conceivable that the vehicle seat upper part should be tilted relative to the vehicle seat lower part in the non-use position. This can be the case with a specific preferred seat inclination. The first connecting element would therefore advantageously have a corresponding length. The predetermined distance between the first axis of rotation and the second axis of rotation from the vehicle seat lower part would then advantageously result from the specified seat inclination. 
     According to a preferred embodiment, the vehicle seat upper part is tilted about a pitch axis relative to the vehicle seat lower part during a pitching movement. The second connecting element is preferably rotated about the first axis of rotation and about the second axis of rotation during this pitching movement. Therefore, due to the pivotable connection of the at least one inner swinging arm and the at least one outer swinging arm, a pitching movement of the vehicle seat upper part relative to the vehicle seat lower part can advantageously be translated and/or converted into a rotary movement of the connecting element about a first axis of rotation relative to the at least one inner swinging arm and about a second axis of rotation relative to the at least one outer swinging arm. 
     According to a further preferred embodiment, the at least one inner swinging arm and the at least one outer swinging arm are each arranged on the vehicle seat lower part by means of at least one lower floating bearing. The at least one inner swinging arm and the at least one outer swinging arm are preferably each arranged on the vehicle seat upper part by means of at least one upper floating bearing. The at least one inner swinging arm or the at least one outer swinging arm are advantageously connected to the vehicle seat lower part by means of a fixed bearing. It is also advantageous in this case that the at least one inner swinging arm or the at least one outer swinging arm are connected to the vehicle seat upper part by means of a further fixed bearing. 
     According to a further advantageous embodiment, the upper fixed bearing is rigidly connected to the arm element. The upper fixed bearing preferably comprises a second arm element which is rigidly connected to the first arm element of the mechanical coupling. The first and the second arm element could advantageously also be designed in one piece or integrally. 
     According to an advantageous embodiment, the first connecting element has a fixed length (L). Therefore, the first connecting element can also be referred to as a connecting rod. The connecting rod is advantageously connected to an inner, outer swinging arm so as to be rotatable about an axis of rotation. Furthermore, the connecting rod is connected to the first arm element of the mechanical coupling so as to be rotatable about an axis of rotation. Such a connecting rod can advantageously ensure parallel guidance between the upper suspension part and the lower suspension part. With a constant length (L) of the connecting rod, the angle of inclination (ξ) is advantageously dependent on a seat height or a height of a vertical cushioning/damping. 
     According to an advantageous embodiment, the length of the first connecting element can be modified. The first connecting element advantageously comprises an actuator by means of which the length (L) can be adjusted. The actuator can advantageously be an electrical actuator, a pneumatic actuator, or a hydraulic actuator. An electrical actuator could for example comprise an electric motor which comprises a screw jack. A control device is also advantageously provided which controls the actuator. A control of the actuator can advantageously comprise an adjustment of the length (L) so that there is no change in the angle of inclination (ξ) when the seat height or the distance between the vehicle seat upper part and the vehicle seat lower part changes. It is thus advantageously possible to keep the inclination of the seat surface constant over a complete height adjustment path by means of the actuator or by means of a connecting rod that can be changed in length. An additional device for adjusting the seat inclination is therefore advantageously not necessary. 
     According to a further advantageous embodiment, a control device is provided which controls the actuator. At least one sensor is preferably provided which is suitable and intended for detecting pitching vibrations of the vehicle seat upper part and is connected to the control device for signalling purposes. Such a sensor can be, for example, a position sensor, a speed sensor or an acceleration sensor. An active cushioning of pitching vibrations of the vehicle seat upper part advantageously takes place by controlling the actuator. The control device advantageously controls the actuator on the basis of the sensor data. Advantageously, the angle of inclination can be actively adapted depending on the driving situation and the vibration deflection. An almost ideal pitching vibration isolation is therefore made possible. 
     According to a further advantageous embodiment, the first connecting element comprises a spring element or spring/damper element. The spring element or spring/damper element preferably allows for passive, semi-active or adaptive cushioning/damping of pitching vibrations of the vehicle seat upper part. A spring element is advantageously provided to bring about a resetting of the vehicle upper part to an initial position. A damper is provided to dissipate the kinetic energy. If a damping system, as will be described below, is already provided, which is suitable and intended to dampen pitching vibrations of the vehicle seat upper part, it is advantageous to provide only one spring element. A combined spring/damper element is advantageous if no further damping system is provided for pitching vibrations. It is of course also conceivable that a spring/damper element and another damping system are provided. In the case of semi-active cushioning/damping, a control device is again provided that controls the spring/damper element. The properties of the spring/damper element, for example the damper hardness, can advantageously be set by the control device. The occupant can advantageously select specific cushioning/damping parameters by means of an operating device which is connected to the control device for signalling purposes. 
     According to a further preferred embodiment, the at least one inner swinging arm and the at least one outer swinging arm are preferably arranged so as to be pivotable relative to the vehicle seat lower part about a third axis of rotation extending along a longitudinal direction. The at least one inner swinging arm, the at least one outer swinging arm and the vehicle seat upper part are advantageously pivoted about the third axis of rotation relative to the vehicle seat lower part during a rolling movement. 
     According to a further preferred embodiment, at least two damping elements are arranged between the vehicle seat upper part and a vehicle seat lower part, said damping elements each extending, inclined at an angle of attack (α), relative to a first axis parallel to the height axis (Z). With such an inclined arrangement of the at least two damping elements, the angle of attack (α) is advantageously less than 90°. Therefore, at least one vertical movement of the vehicle seat upper part relative to the vehicle seat lower part is dampened by the at least two damping elements. The kinetic energy is advantageously dissipated during a damping process. 
     According to a particularly preferred embodiment, four damping elements are arranged between the vehicle seat lower part and the connecting element. In a non-use position of the seat, two damping elements in each case preferably form the legs of an imaginary trapezoid. 
     The base sides of the imaginary trapezoid are preferably formed by the vehicle seat lower part and by the connecting element. A non-use position of the vehicle seat is to be understood as that position in which no vibrations are introduced, for example an unoccupied vehicle seat in a stationary vehicle. The vehicle seat lower part is advantageously designed to be substantially rectangular. The four damping elements preferably form an imaginary trapezoid along each side of the vehicle seat lower part. The arrangement of the four damping elements in the non-use position can advantageously also be viewed as an imaginary truncated pyramid. A corresponding imaginary rectangular lower base area would then be given by the four lower arrangement points of the damping elements. An advantageous upper imaginary base area would be provided by upper points of arrangement of the damping elements on the second connecting element. 
     Due to the pivotable connection of the at least one inner swinging arm and the at least one outer swinging arm, a pitching movement of the vehicle seat upper part relative to the vehicle seat lower part can advantageously be translated and/or converted into a rotary movement of the connecting element about a first axis of rotation relative to the at least one inner swinging arm and about a second axis of rotation relative to the at least one outer swinging arm. Due to the at least two damping elements which are arranged so as to be inclined, the rotational movement of the second connecting element and thus, due to the existing further mechanical coupling, also the corresponding pitching movement of the vehicle seat upper part can be dampened relative to the vehicle seat lower part. A pitching movement is to be understood as a tilting of the vehicle seat upper part relative to the vehicle seat lower part about a pitch axis which extends along the width axis Y. Likewise, the vehicle seat upper part can remain aligned horizontally during a pitching movement and the vehicle seat lower part can tilt about the width axis (Y) relative to the vehicle seat upper part. To dampen a pitching movement, it would be conceivable to provide the at least two damping elements parallel to the height axis (Z), but this would have a detrimental effect on the suspension stroke along the height axis (Z). This disadvantage is advantageously eliminated by the damping elements which are arranged so as to be inclined. 
     In the event of a rolling movement, the vehicle seat upper part pivots relative to the vehicle seat lower part or vice versa about the third axis of rotation. Such a pivoting modifies a lateral distance between the vehicle seat upper part and the vehicle seat lower part, or between the connecting element and the vehicle seat lower part. Due to the inclined arrangement of the damping elements between the vehicle seat lower part and the connecting element, such a rolling movement can also be dampened. To dampen a rolling movement, it would be conceivable to provide the at least two damping elements parallel to the height axis (Z), but this would have a detrimental effect on the suspension stroke along the height axis (Z). This disadvantage is advantageously eliminated by the damping elements which are arranged so as to be inclined. 
     Finally, vertical vibrations can be dampened by the damping elements, during which vibrations the vehicle seat upper part is displaced relative to the vehicle seat lower part. 
     The vehicle seat can preferably also be installed so as to be pivoted by 90° about the Z axis. The pitching movement or the pitch axis would thus become the rolling movement or the roll axis and vice versa. 
     According to a further advantageous embodiment, the damping elements are arranged on the vehicle seat lower part so as to be pivotable about a respective pivot axis. The damping elements are preferably arranged on the connecting element so as to be pivotable about a respective further pivot axis. The above-mentioned advantageous lower arrangement points on the vehicle seat lower part can therefore preferably be designed as rotary bearing elements, on which the respective damping element is arranged so as to be pivotable. Furthermore, the above-mentioned upper arrangement points on the connecting element can preferably be designed as rotary bearing elements, on which the respective damping element is arranged so as to be pivotable. The respective damping element is advantageously connected to the vehicle seat lower part and/or the connecting element by means of a spherical bearing. The respective damper element advantageously has an upper and a lower damper eye, which is preferably designed as a bore or recess. A corresponding pivot bolt can advantageously be arranged in each of these damper eyes, by means of which the respective damping element is connected to the connecting element and/or the vehicle seat lower part. Furthermore, it is advantageous that a sleeve or bushing made of a resilient material, in which the respective pivot bolt is arranged, is provided in one or more of said damper eyes. Such an advantageous (spherical) bearing allows freedom of rotation due to a resilient deformation of the sleeve or bushing, which is advantageous for example if the two pivot axes at the upper and lower end of the damping element are no longer parallel when rotating about the longitudinal axis (X). 
     According to a further preferred embodiment, during a vertical movement of the vehicle seat upper part relative to the vehicle seat lower part, the connecting element is displaced along the height axis (Z). The angle of attack (α) of the damping elements is preferably dependent on a vertical position of the vehicle seat upper part relative to the vehicle seat lower part. Due to the advantageous pivotable arrangement of the damping elements on the connecting element and/or the vehicle seat lower part, during a displacement of the vehicle seat upper part or the connecting element in the vertical direction, i.e. along the height axis (Z), the angle of attack (α) is changed. The angle of attack (α) advantageously extends between a central axis of the respective damping element and the first axis. It is advantageous that the angle of attack (α) can be different for each damping element. The angle of attack (α) is advantageously selected from a range between 10° and 80°. The angle of attack (α) is preferably selected from a range between 15°and 75°. The angle of attack (α) is more preferably selected from a range between 20° and 70°. 
     According to a further preferred embodiment, the vehicle seat upper part is tilted about a pitch axis relative to the vehicle seat lower part during a pitching movement. In this case, a rear portion of the vehicle seat upper part can advantageously be tilted upwards or downwards relative to a front portion of the vehicle seat upper part along the height axis (Z). The connecting element is advantageously rotated about the first axis of rotation and about the second axis of rotation during this pitching movement. A displacement of the swinging arm ends mounted in the floating bearings preferably takes place on different horizontal planes along the height axis (Z). 
     According to a further preferred embodiment, the at least one inner swinging arm, the at least one outer swinging arm and the vehicle seat upper part are pivoted about the third axis of rotation relative to the vehicle seat lower part during a rolling movement. 
     Advantageously, the damping elements dampen the vertical movement of the vehicle seat upper part relative to the vehicle seat lower part, the pitching movement of the vehicle seat upper part about the pitch axis relative to the vehicle seat lower part, and the rolling movement of the vehicle seat upper part about the third axis of rotation relative to the vehicle seat lower part. The damper forces are advantageously divided into the respective components (roll, pitch or vertical) depending on the angle of attack α. 
     According to a further preferred embodiment, the lower floating bearings of the at least one inner swinging arm and the at least one outer swinging arm comprise at least one receiving element. The at least one receiving element is advantageously pivotable about the third axis of rotation relative to the vehicle seat lower part. The lower floating bearings preferably comprise bearing rollers. The at least one receiving element is preferably formed as a guide element, in which bearing rollers are guided along the longitudinal direction X. 
     According to a further preferred embodiment, the scissor frame arrangement comprises two inner swinging arms which form an inner swinging arm pair. The scissor frame arrangement preferably further comprises two outer swinging arms which form an outer swinging arm pair. The two inner swinging arms advantageously have swinging arm ends which are connected by means of a swinging arm bolt. The bearing rollers are preferably arranged on the swinging arm bolt. The two outer swinging arms advantageously have swinging arm ends which are connected by means of a swinging arm bolt. The bearing rollers are preferably arranged on the swinging arm bolt. 
     According to a further preferred embodiment, at least one spring element is provided in addition to the damper elements, by means of which a displacement of the vehicle seat upper part relative to the vehicle seat lower part due to the vibration effect can be reset by a vertical movement, a pitching movement, or a rolling movement. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages, aims and characteristics of the present invention are explained with reference to the following description of the attached drawings. Similar components may have the same reference signs in the various embodiments. 
       In the drawings: 
         FIG. 1  is an outline sketch of the vehicle seat in accordance with one embodiment; 
         FIG. 2 a , 2 b    are outline sketches of the vehicle seat in accordance with one embodiment; 
         FIG. 3  is a view of the inner swinging arm pair and the outer swinging arm pair; 
         FIG. 4 a , 4 b    are views of the connecting element; 
         FIG. 5  is a view of the inner swinging arm pair and the outer swinging arm pair in accordance with a further embodiment; 
         FIG. 6  is a front view of the vehicle seat in accordance with one embodiment; 
         FIG. 7  is a sectional view along the axis A-A in  FIG. 6 ; 
         FIG. 8  is a sectional view along the axis B-B in  FIG. 6 ; 
         FIG. 9  is a sectional view along the axis A-A in accordance with a further embodiment; 
         FIG. 10  is a sectional view along the axis A-A in accordance with a further embodiment; 
         FIG. 11  is a side view of the vehicle seat in accordance with one embodiment after a pitching movement; 
         FIG. 12  is a side view of the vehicle seat in accordance with one embodiment after a pitching movement; 
         FIG. 13  is a front view of the vehicle seat in accordance with one embodiment after a pitching movement; 
         FIG. 14  is a front view of the vehicle seat in accordance with one embodiment after a rolling movement; 
         FIG. 15 a    is a front view of the vehicle seat in accordance with one embodiment in a central position along the height axis Z; 
         FIG. 15 b    is a front view of the vehicle seat in accordance with one embodiment in an upper and a lower position along the height axis Z; 
         FIG. 16 a    is a side view of the vehicle seat in accordance with one embodiment in a central position along the height axis Z; 
         FIG. 16 b    is a side view of the vehicle seat in accordance with one embodiment in an upper and a lower position along the height axis Z; 
         FIG. 17  is a top view of the vehicle seat in accordance with one embodiment; 
         FIG. 18  is an isometric view of the vehicle seat in accordance with one embodiment; 
         FIG. 19  is an isometric view of the vehicle seat in accordance with one embodiment after a pitching movement; 
     
    
    
     DETAILED DESCRIPTION 
     In  FIGS. 1 to 19 , a vehicle seat  1  is shown comprising a vehicle seat upper part  2  and a vehicle seat lower part  3 , which are spaced apart from one another along a height axis Z and are connected to one another by means of a scissor frame arrangement  4 , wherein the scissor frame arrangement  4  comprises at least one inner swinging arm  5 ,  5   a  and at least one outer swinging arm  6 ,  6   a , wherein the at least one inner swinging arm  5 ,  5   a  and the at least one outer swinging arm  6 ,  6   a  are mechanically coupled, whereby an angle of inclination ξ of the vehicle seat upper part  2  relative to the vehicle seat lower part  3  can be specified, wherein the mechanical coupling  7  comprises an arm element  8  and a first connecting element  9  pivotably connected thereto, wherein the angle of inclination ξ can be specified by a length L of the first connecting element  9 . 
     Therefore, the vehicle seat  1  extends along the height axis Z, the width axis Y and the longitudinal axis X. The vehicle seat comprises other elements such as a seat cushion  35  and a backrest  36 , which can be arranged on the vehicle seat upper part  2 . This can be seen in  FIGS. 2 a  and 2 b   . Merely for reasons of clarity, the mechanical coupling  7  was not shown in  FIGS. 2 a  and 2 b   . In the remaining drawings, these elements are not shown for reasons of clarity. Further embodiments are also conceivable which comprise further elements, such as armrests. The vehicle seat lower part  3  can be arranged on a vehicle body. 
     The arm element  8  extends along the longitudinal axis X from the centre of the vehicle seat  1 . Furthermore, it extends inclined downwards along the height axis Z, i.e. towards the vehicle seat lower part  3 . The first connecting element  9  extends upwards along the height axis Z, i.e. towards the vehicle seat upper part  2 . Therefore, the arm element  8  and the connecting element  9  are arranged in a substantially triangular shape. In the case of a horizontal orientation of the vehicle seat upper part  2 , the arm element  8  preferably has a greater length than the connecting element  9  (length L). 
     The at least one inner swinging arm  5 ,  5   a  and the at least one outer swinging arm  6 ,  6   a  are connected by a second connecting element  10  which can be rotated about a first axis of rotation  16  or a second axis of rotation  17  extending along a width direction Y relative to the at least one inner swinging arm  5 ,  5   a  and relative to the at least one outer swinging arm  6 ,  6   a . The at least one inner swinging arm  5 ,  5   a  and the at least one outer swinging arm  6 ,  6   a  are arranged so as to be pivotable relative to the vehicle seat lower part  3  about a third axis of rotation  18  extending along a longitudinal direction X. 
     The at least one inner swinging arm  5 ,  5   a  and the at least one outer swinging arm  6 ,  6   a  intersect in an intersection region K. At least in a non-use position, the first axis of rotation  16  and the second axis of rotation  17  are arranged along the height axis Z above the intersection region K or along the height axis Z below the intersection region K. Furthermore, the first axis of rotation  16  and the second axis of rotation  17  are, at least in a non-use position, at the same distance along the height axis Z from the vehicle seat lower part  3 . Therefore, the second connecting element  10  is not rotated and is aligned so as to be substantially horizontal and/or parallel to the longitudinal axis X. A central axis M can also be defined, which runs through the intersection point K. This is clearly visible in  FIGS. 2 a    and  2   b.    
     The first axis of rotation  16  and the second axis of rotation  17  are, at least in a non-use position, at the same horizontal distance from the central axis M. The second connecting element  10  is arranged by means of further connecting elements  42  on the at least one inner swinging arm  5  or the at least one outer swinging arm  6 . The further connecting elements  42  are suitable for producing a rotatable connection between the second connecting element  10  and the at least one inner swinging arm  5  or the at least one outer swinging arm  6 . The further connecting elements  42  extend along the first axis of rotation  16  and/or the second axis of rotation  17  and can be designed as bolts or screws. For this purpose, there are corresponding central bearing bores  41  provided in the at least one inner swinging arm  5  and/or the at least one outer swinging arm  6 , in which these further connecting elements  42  are received. 
     The at least one inner swinging arm  5 ,  5   a  and the at least one outer swinging arm  6 ,  6   a  are arranged on the vehicle seat lower part  3  by means of at least one lower floating bearing  20 ,  21 . Furthermore, the at least one inner swinging arm  5 ,  5   a  and the at least one outer swinging arm  6 ,  6   a  are each arranged on the vehicle seat upper part  2  by means of at least one upper floating bearing  22 ,  23 . 
     The scissor frame arrangement  4  comprises an inner swinging arm pair  5   a  and an outer swinging arm pair  6   a , as shown in  FIGS. 3 and 5  for example. According to the embodiment in 
       FIG. 3 , both the inner swinging arm pair  5   a  and the outer swinging arm pair  6   a  have a continuous swinging arm bolt  33 ,  34  at the respective swinging arm ends. The respective bearing rollers  28   a ,  28   b ,  29   a ,  29   b  are arranged on these swinging arm bolts  33 ,  34 . This is clearly visible by way of example in  FIG. 18 . The inner swinging arm pair  5   a  accordingly has an upper swinging arm bolt  33   b  on which two bearing rollers  29   b  are arranged in each case, which are associated with the upper floating bearing  23  of the inner swinging arm pair  5   a . Furthermore, the inner swinging arm pair  5   a  has a lower swinging arm bolt  33   a  on which two bearing rollers  29   a  are arranged in each case, which are associated with the lower floating bearing  21  of the inner swinging arm pair  5   a . The outer swinging arm pair  6   a  also has accordingly an upper swinging arm bolt  34   b , on which two bearing rollers  28   b  are arranged in each case, which are associated with the upper floating bearing  22  of the outer swinging arm pair  6   a . Furthermore, the outer swinging arm pair  6   a  has a lower swinging arm bolt  34   a , on which two bearing rollers  28   a  are arranged in each case, which are associated with the lower floating bearing  20  of the outer swinging arm pair  6   a . Furthermore, the further connecting element  42 , by means of which a rotatable connection between the second connecting element  10  and the at least one inner swinging arm  5  or the at least one outer swinging arm  6  is established, can be designed as a continuous bolt that extends along the respective axis of rotation  16 ,  17 . Therefore, the second connecting element  10  would be arranged on the at least one inner swinging arm  5  or the at least one outer swinging arm  6  by means of two bolts. Furthermore, it would be conceivable that two non-continuous bolts and/or screws are provided as further connecting elements  42  for each swinging arm pair  5   a ,  6   a . Therefore, the second connecting element  10  would be arranged on the at least one inner swinging arm  5 ,  5   a  and the at least one outer swinging arm  6 ,  6   a  by means of a total of four bolts. According to the embodiment in  FIG. 5 , the further connecting element  42  is designed as a bolt and/or a screw. According to the embodiment in  FIG. 11 , the further connecting element  42  is designed as a continuous bolt or shaft. 
     According to the embodiment in  FIG. 5 , the swinging arm pairs  5   a ,  6   a  do not have a continuous swinging arm bolt at the swinging arm ends. Rather, a bearing device for the respective bearing rollers  28   a ,  28   b ,  29   a ,  29   b  is provided at each swinging arm end which, analogously to the embodiment described in  FIG. 3 , are associated with the upper floating bearings  22 ,  23  or the lower floating bearings  20 ,  21 . 
     The upper bearing rollers  28   b ,  29   b  are each guided in upper guide elements  30   b . The lower bearing rollers  28   a ,  29   a  are each guided in lower guide elements  30   a . In  FIG. 2 a   , it can also be seen that the lower bearing rollers  28   a ,  29   a  are at a smaller distance from the central axis M than the upper bearing rollers  28   b ,  29   b  in a non-use position. 
     Furthermore, the at least one inner swinging arm  5 ,  5   a  or the at least one outer swinging arm  6 ,  6   a  are connected to the vehicle seat lower part  3  by means of a fixed bearing  24 , the at least one inner swinging arm  5 ,  5   a  or the at least one outer swinging arm  6 ,  6   a  being connected to the vehicle seat upper part  2  by means of a further fixed bearing  25 . By providing the fixed bearings  24 ,  25 , an indefinite guidance caused by the provision of the four floating bearings  20 ,  21 ,  22 ,  23  is avoided. 
     The upper fixed bearing  24  comprises a lever arm  37  which is arranged so as to be rotatable on a rear region along the longitudinal direction X and an upper region of the at least one outer swinging arm  6 ,  6   a  along the height direction Z. Therefore, this lever arm  37  is arranged so as to be rotatable on the at least one outer swinging arm  6  between the upper swinging arm bolt  34   b  and the intersection point K or the connection of the connecting element  7  to the at least one outer swinging arm  6 ,  6   a  that is rotatable about the first axis of rotation  8 . Furthermore, the lever arm  37  is arranged so as to be rotatable on the vehicle seat upper part  2 . The lever arm  37  can be pivoted about a fourth axis of rotation  38  relative to the vehicle seat upper part  2 . The fourth axis of rotation  38  and the first axis of rotation  16  are advantageously spaced apart from one another along the height axis Z. Furthermore, the fourth axis of rotation  38  and the first axis of rotation  16  are, at least in a non-use position, at the same distance from the central axis M. 
     The lower fixed bearing  25  also comprises a lever arm  39  which is arranged so as to be rotatable on a rear region along the longitudinal direction X and the lower region of the at least one inner swinging arm  5 ,  5   a  along the height direction Z. Therefore, this lever arm  39  is arranged so as to be rotatable on the at least one inner swinging arm  5  between the lower swinging arm bolt  33   a  and the intersection point K. Furthermore, the lever arm  39  is arranged so as to be rotatable on the vehicle seat lower part  3 . The lever arm  39  can be pivoted about a fifth axis of rotation  40  relative to the vehicle seat lower part  3 . The fifth axis of rotation  40  and the second axis of rotation  17  are advantageously spaced apart from one another along the height axis Z. Furthermore, the fifth axis of rotation  40  and the second axis of rotation  17  are, at least in a non-use position, at the same distance from the central axis M. 
     Such a configuration of the floating bearings  20 ,  21 ,  22 ,  23  and the fixed bearings  23 ,  24  ensures that the intersection point or the second connecting element  10  always remains central due to a lifting movement. 
     The arm element  8  is arranged on the at least one inner swinging arm  5 ,  5   a  and the first connecting element  9  on the at least one outer swinging arm  6 ,  6   a . Of course, the arm element  8  can also be arranged on the at least one outer swinging arm  6 ,  6   a  and the first connecting element  9  can be arranged on the at least one inner swinging arm  5 ,  5   a . An embodiment is shown in  FIG. 5  in which the arm element  8  is connected to both inner swinging arms  5  of the inner swinging arm pair  5   a . The first connecting element  9  is connected to both outer swinging arms  6  of the outer swinging arm pair  6   a . The first connecting element  9  is rotatably connected to the arm element  8  about a sixth axis of rotation  54  and is rotatably connected to the at least one inner swinging arm  5 ,  5   a  or to the at least one outer swinging arm  6 ,  6   a  about a seventh axis of rotation  55 . The arm element  8  is arranged about an eighth axis of rotation  56  on the at least one inner swinging arm  5 ,  5   a  or the at least one outer swinging arm  6 ,  6   a . The lever arm  37  of the upper fixed bearing  24  can have a rigid connection to the arm element  8 . The lever arm  37  of the upper fixed bearing  24  can also be designed in one piece or integrally with the arm element  8 . This is shown for example in  FIG. 8 . 
     The arm element  8  extends along the longitudinal axis X and inclined downwards along the height axis Z. With a horizontal orientation of the vehicle seat upper part  2 , the arm element  8  can preferably run substantially parallel to a swinging arm  5 ,  5   a ,  6 ,  6   a . The arm element  8  and the connecting element  9  are arranged substantially in a triangular manner, an angle μ between the arm element  8  and the connecting element  9 , or between their central axes  8   a ,  9   a , depending on the angle of inclination ξ. The angle μ is preferably between 10° and 90°. As can be seen from  FIGS. 11 and 12 , in the case of an inclination change, an angle of attack A, which extends between the connecting element  9  or a central axis  9   a  of the connecting element  9  and the vehicle seat lower part  3 , changes. The angle of attack λ is preferably in a range between 10° and 90°. 
     According to an embodiment in accordance with  FIGS. 5 and 8 , the first connecting element  9  has a fixed length (L). Therefore, the first connecting element  9  can also be referred to as a connecting rod. The connecting rod  9  is connected to an inner, outer) swinging arm  5 ,  5   a ,  6 ,  6   a  such that it can rotate about the seventh axis of rotation  55 . Furthermore, the connecting rod  9  is connected to the first arm element  8  of the mechanical coupling  7  so as to be rotatable about the sixth axis of rotation  54 . Such a connecting rod  9  ensures parallel guidance between the upper suspension part  2  and the lower suspension part  3 . With a constant length (L) of the connecting rod  9 , the angle of inclination (ξ) is dependent on a seat height or a height of a vertical cushioning/damping. 
     The first connecting element  9  can, however, also be designed in such a way that the length L thereof can be modified. This is shown schematically in  FIG. 10 . The first connecting element  9  can comprise an actuator  31  by means of which the length L can be adjusted. Such an actuator  31  can be electrical, pneumatic or hydraulic. Furthermore, a control device  32  can be provided which controls the actuator  31 . The control device  32  can be connected for signalling purposes to at least one sensor  50  which is suitable and intended to detect pitching vibrations of the vehicle seat upper part  2  and/or the vehicle seat lower part  3  and/or the body floor. Such a configuration allows for active cushioning of pitching vibrations of the vehicle seat upper part  2  and/or the vehicle seat lower part  3  and/or the body floor by controlling the actuator  31 . 
     When the seat height is changed, the vertical distance between the vehicle seat upper part  2  and the vehicle seat lower part  3  is changed. The seat height also changes in the event of vertical vibrations, but this is dampened by the damping system. A corresponding cushioning system can also be provided, which brings about a corresponding resetting effect. With a fixed length L of the first connecting element  9 , the angle of inclination ξ changes when the seat height changes. In the case of dampened, preferably cushioned, vertical vibrations, such an angle change can generally be neglected. During a seat height adjustment by the user, it is advantageous if the control device readjusts the length L of the first connecting element  9  accordingly so that the angle of inclination ξ is maintained for the newly set seat height. 
     According to a further advantageous embodiment, the first connecting element  9  comprises a spring element or spring/damper element  51 . The spring element or spring/damper element  51  preferably allows for passive, semi-active or adaptive cushioning/damping of pitching vibrations of the vehicle seat upper part  2 . The spring/damper element  51  can be designed so as to be passive, semi-active or adaptive, a semi-active configuration being provided with a control device  31  which controls the spring/damper element  51  accordingly. 
     During both active and semi-active control, an operating device  57  can be provided which is connected to the control device  31  for signalling purposes and by means of which an occupant can assign corresponding parameters. 
     The at least one inner swinging arm  5 ,  5   a  and the at least one outer swinging arm  6 ,  6   a  are arranged so as to be pivotable relative to the vehicle seat lower part  3  about a third axis of rotation  18  extending along a longitudinal direction X. The at least one inner swinging arm  5 ,  5   a , the at least one outer swinging arm  6 ,  6   a  and the vehicle seat upper part  2  are pivoted about the third axis of rotation  18  relative to the vehicle seat lower part  3  during a rolling movement. 
     Furthermore, at least two damping elements  11 ,  12 ,  13 ,  14  are arranged between the vehicle seat upper part  2  and the vehicle seat lower part  3 , said damping elements each extending, inclined at an angle of attack α, relative to a first axis  15  parallel to the height axis Z. 
     Four damping elements  11 ,  12 ,  13 ,  14  are advantageously arranged between the vehicle seat lower part  3  and the second connecting element  10 . In a non-use position of the vehicle seat  1 , two damping elements  11 ,  12 ,  13 ,  14  in each case form the legs of an imaginary trapezoid  52 . The arrangement of the four damping elements  11 ,  12 ,  13 ,  14  can also be viewed to the effect that, together with a portion of the vehicle seat lower part  3  and the second connecting element  10 , they form an imaginary truncated pyramid  53 . 
     The damping elements  11 ,  12 ,  13 ,  14  are arranged on the vehicle seat lower part  3  so as to be pivotable about a respective pivot axis  19   a , which damping elements are clearly visible by way of example in  FIG. 17 . Furthermore, the damping elements  11 ,  12 ,  13 ,  14  are arranged on the second connecting element  10  so as to be pivotable about a further respective pivot axis  19   b . For this purpose, the second connecting element  10  has corresponding receptacles  43 , on which the damping elements  11 ,  12 ,  13 ,  14  can be arranged so as to be pivotable. 
     This is clearly visible in  FIGS. 4 a  and 4 b   . Corresponding receptacles  45  are also provided on the vehicle seat lower part  3 , on which the damping elements  11 ,  12 ,  13 ,  14  can be arranged so as to be pivotable. 
     During a vertical movement of the vehicle seat upper part  2  relative to the vehicle seat lower part  3 , the second connecting element  10  is displaced along the height axis Z; accordingly, all four damping elements  11 ,  12 ,  13 ,  14  are modified in length. Furthermore, with such a vertical movement of the vehicle seat upper part  2  by the pivotable arrangement of the damping elements  11 ,  12 ,  13 ,  14 , the angle of attack α of the damping elements  11 ,  12 ,  13 ,  14  is modified accordingly. The angle of attack α extends between a central axis  11   a ,  12   a ,  13   a ,  14   a  of the respective damping element  11 ,  12 ,  13 ,  14  and the first axis  15 . Accordingly, the vertical movement of the vehicle seat upper part  2  is dampened by the damping elements  11 ,  12 ,  13 ,  14 . This is clearly visible in  FIGS. 15 and 16 .  FIGS. 15 a  and 16 a    show a state in which the vehicle seat is in a central vertical position. Furthermore, a vehicle seat  1  is shown in  FIGS. 15 b  and 16 b   , which is in an upper (represented as a dashed line) or in a lower vertical position. 
     In  FIGS. 2 b   ,  9  to  13  and  19 , a vehicle seat  1  is shown in which the vehicle seat upper part  2  has experienced a pitching movement relative to the vehicle seat lower part  3 . During such a pitching movement, the vehicle seat upper part  2  is tilted about a pitch axis  26  relative to the vehicle seat lower part  3 . The tilting can be expressed in the angle of inclination ξ. In the process, a displacement of the swinging arm ends mounted in the upper floating bearings  22 ,  23  takes place on different horizontal planes along the height axis Z. In addition, the second connecting element  10  is rotated about the first axis of rotation  16  and the second axis of rotation  17 . By this rotation of the second connecting element  10 , the damping elements  11 ,  12 ,  13 ,  14  are lengthened or shortened in accordance with the direction of rotation. The pitching movement is thus dampened. As can be seen from the drawings, it is advantageous that the connecting element is tilted and/or rotated in the counter direction relative to the vehicle seat upper part  2 . Analogously to this, a pitching movement can also take place in such a way that the vehicle seat upper part  2  retains its horizontal position and the vehicle seat lower part  3  tilts accordingly. Accordingly, the displacement of the axes of the lower floating bearings  20 ,  21  takes place into other horizontal planes. Analogously, the second connecting element  10  is also rotated about the first axis of rotation  16  and the second axis of rotation  17  in this case. By this rotation of the second connecting element  10 , the damping elements  11 ,  12 ,  13 ,  14  are lengthened or shortened in accordance with the direction of rotation. The pitching movement is thus dampened. 
     In addition to damping the vertical movement of the vehicle seat upper part  2  and the pitching movement, a rolling movement can also be dampened by means of the damping elements  11 ,  12 ,  13 ,  14 . For this purpose, the at least one inner swinging arm  5 ,  5   a , the at least one outer swinging arm  6 ,  6   a  and the vehicle seat upper part  2  can be pivoted relative to the vehicle seat lower part  3  about a third axis of rotation  18  extending along the longitudinal direction X. Such a rolling movement is shown in  FIG. 14 . As a result of the pivoting about the third axis of rotation  18 , the orientation of the vehicle seat upper part  2  changes relative to the vehicle seat lower part  3 . The vehicle seat upper part  2  and the vehicle seat lower part  3  each extend in a starting position in one plane. The plane in which the vehicle seat upper part  2  extends can be described by the vectors Al and A 2 . The plane in which the vehicle seat lower part  3  extends can be described by the vectors A 3  and A 4 . In a starting position in which the vehicle seat upper part  2  and the vehicle seat lower part  3  are arranged parallel to one another, the vectors A 2  and A 4  would be arranged parallel to the width axis Y and the vectors A 1  and A 3  would arranged be parallel to the longitudinal axis X. In the event of a rolling movement, the vectors A 2  and A 4  have an angle θ≠0°, 180°. This is shown, for example, in  FIG. 11 , the vectors A 1  and A 3  being directed into the plane of the drawing. In the event of a rolling movement, a distance changes between the pivot axis  19   b  with respect to an upper connection of a damper element  11 ,  12 ,  13 ,  14  to the second connecting element  10  and between the pivot axis  19   a  with respect to a lower connection of a damper element  11 ,  12 ,  13 ,  14  to the vehicle seat lower part  3 . Therefore, the damper elements  11 ,  12 ,  13 ,  14  are shortened or lengthened accordingly, as a result of which the rolling movement is dampened. 
     The lower floating bearings  20 ,  21  of the at least one inner swinging arm  5 ,  5   a  and the at least one outer swinging arm  6 ,  6   a  comprise at least one receiving element  27  which is pivotable about the third axis of rotation  18  relative to the vehicle seat lower part  3 .  FIG. 18  shows an embodiment in which the receiving element  27  and guide element  30   a  is formed in which the lower bearing rollers  28   a ,  29   a  are guided. The guide element is designed as a substantially plate-like element which extends along the longitudinal extent of the vehicle seat lower part  3  and is arranged substantially centrally thereon. The vehicle seat lower part  3  has a fastening element  44  on each of its two longitudinal sides. On this fastening element  44 , the guide element  30   a  is mounted so as to be rotatable about the third axis of rotation  18 , in each case by means of a rotary bearing. The receptacles  45 , on which the damping elements  11 ,  12 ,  13 ,  14  are arranged so as to be pivotable, are also arranged laterally on the fastening element  44  or are integrated therein. The lower fixed bearing  25  is also arranged on the plate-like element. 
     According to the embodiment in accordance with  FIG. 5 , no lower bearing rollers  28   a ,  29   a  are provided. The at least one inner swinging arm  5 ,  5   a  and the at least one outer swinging arm  6 ,  6   a  are connected in each case to a sliding element  46 , which can slide along the longitudinal direction X on a continuous sliding rail  47 . The sliding rail  47  is connected to the holding element  48  and extends along the third axis of rotation  18 . In the event of a rolling movement, the sliding elements  46  can be rotated about the third axis of rotation  18  and/or the fixed sliding rail  47 . The lower fixed bearing  25  is also connected to the sliding rail  47 . In a further embodiment (not shown in this case), the sliding rail is designed as a torque-transmitting square shaft. This square shaft is then mounted so as to be rotatable on the holding element  48  and/or the receptacles thereof. In this embodiment, it then applies that the sliding elements  46  execute the x movement on the sliding rail  47  and the rolling movement is realised by rotating the sliding rail  47 . 
     In  FIG. 15 a   , the front view of the vehicle seat  1  is shown. A projected angle of attack β is also shown. The projected angle of attack β in the plane of the front view mainly determines the division of the damper forces into the components about a roll axis or about the third axis of rotation  18  and in the vertical direction. A side view of the vehicle seat  1  is shown in  FIG. 16   a.    
     Furthermore, a projected angle of attack γ is shown. The projected angle of attack γ in the plane of the side view mainly determines the division of the damper forces into the components about the pitch axis and in the vertical direction. Therefore, it can be seen that the damper forces of the damping elements  11 ,  12 ,  13 ,  14  are divided into the respective components with regard to a rolling movement, a pitching movement and a vertical movement, depending on the angle of attack α. 
     In order to allow a corresponding resetting of the pitching movement, the rolling movement and the vertical movement, spring element  49  can be arranged parallel to the damping elements  11 ,  12 ,  13 ,  14  between the connecting element  7  and the vehicle seat lower part  3 . 
     The arrangement and the function of the spring elements  49  can be described analogously to the damper elements  11 ,  12 ,  13 ,  14  with the difference that a resetting operation is effected instead of the dissipative function. In  FIGS. 6 to 10 , receptacles  58  for these spring elements  49  are shown, which spring elements can also be arranged so as to be inclined relative to the first axis  15 .  FIG. 1  shows the spring element  49  which are arranged so as to be inclined. 
     All features disclosed in the application documents are claimed as being substantial to the invention, provided that they are, individually or in combination, novel over the prior art. 
     LIST OF REFERENCE SIGNS 
     
         
           1  vehicle seat 
           2  vehicle seat upper part 
           3  vehicle seat lower part 
           4  scissor frame arrangement 
           5  at least one inner swinging arm 
           5   a  inner swinging arm pair 
           6  at least one outer swinging arm 
           6   a  outer swinging arm pair 
           7  mechanical coupling 
           8  arm element 
           8   a  central axis of the arm element 
           9  first connecting element 
           9   a  central axis of the first connecting element 
           10  second connecting element 
           11  damping element 
           11   a  central axis of the damping element 
           12  damping element 
           12   a  central axis of the damping element 
           13  damping element 
           13   a  central axis of the damping element 
           14  damping element 
           14   a  central axis of the damping element 
           15  first axis 
           16  first axis of rotation 
           17  second axis of rotation 
           18  third axis of rotation 
           19   a  pivot axis 
           19   b  pivot axis 
           20  lower floating bearing of the outer swinging arm pair 
           21  lower floating bearing of the inner swinging arm pair 
           22  upper floating bearing of the outer swinging arm pair 
           23  upper floating bearing of the inner swinging arm pair 
           24  upper fixed bearing 
           25  lower fixed bearing 
           26  pitch axis 
           27  receiving element 
           28   a  lower bearing rollers 
           28   b  upper bearing rollers 
           29   a  lower bearing rollers 
           29   b  upper bearing rollers 
           30   a  lower guide element 
           30   b  upper guide element 
           31  actuator 
           32  control device 
           33   a  lower swinging arm bolt 
           33   b  upper swinging arm bolt 
           34   a  upper swinging arm bolt 
           34   b  lower swinging arm bolt 
           35  seat cushion 
           36  backrest 
           37  lever arm 
           38  fourth axis of rotation 
           39  lever arm 
           40  fifth axis of rotation 
           41  central bearing bores 
           42  further connecting element 
           43  receptacles of the connecting element 
           44  fastening element 
           45  receptacles 
           46  sliding element 
           47  sliding rail 
           48  holding element 
           49  spring element 
           50  sensor 
           51  spring/damper element 
           52  imaginary trapezoid 
           53  imaginary truncated pyramid 
           54  sixth axis of rotation 
           55  seventh axis of rotation 
           56  eighth axis of rotation 
           57  operating device 
           58  receptacle 
         A 1  vector 
         A 2  vector 
         A 3  vector 
         A 4  vector 
         K intersection region 
         L length of the first connecting element 
         M central axis 
         Z height axis 
         X longitudinal axis 
         Y width axis 
         α angle of attack 
         β angle 
         γ angle 
         θ angle 
         ξ angle of inclination 
         μ angle 
         λ angle