EP3311704A1 - Backrest device - Google Patents

Abstract

A backrest device (1) comprises a backrest support (3) with a support arm (31), a backrest (2) mounted on the support arm (31) and an adjusting member (4) which can be adjusted between a blocking position and a movement position. The support arm (31) of the backrest support (3) is equipped with a latching row (311). The backrest (2) is movable along the support arm (31). The actuator (4) is connected to the backrest (2) and has an engagement piece (413). In the blocking position, the engagement piece (413) of the actuator (4) engages in the latching row (311) of the support arm (31) of the backrest support (3), so that movement of the backrest (2) along the support arm (31) of the backrest support (3). 3) is locked. In the movement position, the engagement piece (413) of the actuator (4) is out of engagement with the latching row (311) of the support arm (31) of the backrest support (3), so that the backrest (2) along the support arm (31) of the backrest support (3 ) is movable. The actuator (4) is made in one piece from an elastic material, wherein it is elastically deformed in the movement position by a manually applied force, so that the engagement piece (413) of the actuator (4) from the detent row (311) of the support arm (31). of the backrest support (3) is moved.

Description

Technical area

The invention relates to a backrest device according to the preamble of independent claim 1. With such backrest devices backrests can be provided adjustable in height in a chair and in particular an office chair.

State of the art

Many chairs and especially many office chairs today are equipped with backrests that are designed to allow ergonomic seating. For this purpose, for example, the backrests are connected via a two arms having backrest support with a chair base or a seat. The backrest support can on the one hand leave a resilient movement of the backrest to the rear and on the other hand a resilient movement in a lateral direction or a twisting movement to a certain extent.

Backrests are often height adjustable to accommodate a user. For example, in the EP 2 721 962 A1 describes a backrest in which a base plate of a backrest is height-adjustable mounted on two webs of a seat backrest connected to a support. On the base plate a dorsokinetic bearing is arranged, which allows rotational movements. For height adjustment, the webs are each equipped with a series of locking structures. On the base plate, a locking lever, mounted via springs button and a cover are mounted. In this case, the locking lever is designed to be in the Intervene locking structures of the webs. By the button is pressed against the spring force upwards, the locking lever is disengaged with respect to the latching structures. In this position, the base plate along the webs can be moved down and up. As soon as the button is released, the springs press them down again and the locking lever optionally engages elsewhere in the latching structures of the webs. The base plate is connected in this position again with the webs and thus the backrest carrier stationary.

A disadvantage of devices for adjusting the height of backrests such as the device described above is that typically comparatively many components are present, which must be assembled relatively complicated. This makes the production of chair backs or chairs relatively expensive and expensive. In addition, such are also relatively difficult to maintain, for example, if individual components must be replaced. Next, such known devices are usually relatively bulky and voluminous, which is often undesirable, among other things, for aesthetic reasons.

Object of the following invention is therefore to propose a backrest device that can be relatively easily installed and maintained and takes up the least possible space.

Presentation of the invention

The object is achieved according to the invention by a backrest device as defined in independent claim 1. Advantageous embodiments of the invention will become apparent from the dependent claims.

The essence of the invention consists in the following: A backrest device for a chair and in particular an office chair comprises a backrest support with a support arm, a backrest mounted on the support arm and an adjustable between a blocking position and a movement position actuator. The support arm of the backrest carrier is equipped with a latching row. The actuator is connected to the backrest and has an engaging piece. In the blocking position, the engaging piece of the actuator engages in the latching row of the support arm the backrest support, so that a movement of the backrest along the support arm of the backrest support is locked. In the movement position, the engaging piece of the actuator is out of engagement with the locking row of the support arm of the backrest support, so that the backrest is typically movable almost vertically along the support arm of the backrest support.

The actuator is in particular made in one piece from an elastic material, wherein it is elastically deformed in the movement position by a typically manually applied force, so that the engagement piece of the actuator is moved or pulled out of the detent row of the support arm of the backrest support.

The detent row may in particular be a series of detent elements, for example a row of teeth, ie a row of teeth. In this case, the latching elements or the teeth can be formed and dimensioned congruent to the engaging piece of the actuator.

In particular, the backrest can therefore be moved substantially vertically downwards and upwards along the support arm. The term "quasi-vertical" may refer to an orientation of the backrest. In addition to a precisely vertical direction, this term also encompasses deviating directions, as occurs in particular with different inclinations of the backrest.

The backrest may comprise a frame supporting or tensioning a leaning structure such as a shell, a cloth or a cushion. In such an embodiment, the frame of the backrest may be mounted on the backrest support.

The engaging piece may be formed as a projection or as a nose. In particular, it can be dimensioned and shaped in such a way that it can, as it were, fit flush into the latching row. So it may be formed congruent to the detent row.

The support arm of the backrest support may be tubular or post-shaped. It can be straight or curved as needed.

The term "manually applied force" may refer in particular to the fact that a user operates the actuator with his hand. He can do that For example, pull with his hand on the actuator until it is sufficiently deformed so that the engaging piece is removed from the detent row or no longer engaged with it.

The elastic material of the actuator allows it to move back to its original position after the force is no longer effective. In particular, the elasticity of the actuator may allow it to automatically return to the blocking position. This allows a comfortable and safe operation of the actuator.

The inventive backrest device allows an efficient implementation of a height-adjustable backrest on a chair with relatively few components. In particular, according to the invention except the backrest and the backrest support only a single further component, namely the actuator needed. Thus, a height adjustment can be easily provided in a chair. Also, the maintenance of the moving parts can be done so efficiently and easily. In addition, such a one-piece implementation requires relatively little space.

Preferably, the backrest on a support arm, wherein the backrest is mounted on the backrest support by the support arm of the backrest support is mounted in the Tragarmfassung the backrest. If the backrest has a frame, the Tragarmfassung may be formed thereon or therein. Such a configuration with a Tragarmfassung in which the support arm is arranged, allows stable movement of the backrest along the backrest support. In addition, it allows a simple construction of the backrest device in a stable design.

Preferably, the backrest support is equipped with a further support arm on which the backrest is mounted, wherein the further support arm is equipped with a further latching row, the actuator has a further engagement piece, in the blocking position the further engagement piece of the actuator in the further latching row of the other support arm engages the backrest support, in the movement position, the further engagement piece of the actuator is out of engagement with the further locking row of the other support arm of the backrest support, and the actuator is elastically deformed in the movement position by the manually applied force that the other Eingreifstück the actuator is pulled from the further detent row of the other arm of the backrest carrier.

So can be moved or pulled together by the same preferably manually applied force, the engagement piece and the further engagement piece together from the detent row and the further detent row.

The further support arm can in particular run approximately parallel to the support arm. This allows a relatively simple, robust and stable construction. In particular, the two support arms allow the backrest to be stably supported but still be tiltable to some extent in a lateral direction. Thus, the backrest can allow the user to move in different directions.

In this case, the backrest preferably has a further Tragarmfassung, wherein the backrest is mounted on the backrest support by the further support arm of the backrest support is mounted in the other Tragarmfassung the backrest.

Preferably, the actuator on a gripping portion for manual actuation of the actuator, in particular in the movement position. Such a gripping portion allows easy and efficient manual operation of the actuator. In this case, the actuator preferably comprises two arm portions, on each of which one of the engagement piece and the further engagement piece is arranged. The two arm sections can be shaped and dimensioned according to the support arms of the backrest carrier. In this case, the gripping portion of the actuator preferably connects the two arm portions with each other. The actuator may therefore be substantially U-shaped in a plan view. Such a gripping portion allows easy operation of the actuator. In particular, so the two engaging pieces can be pulled in one of the two rows of detents.

Preferably, the arm portions of the actuator each have a first longitudinal end and a second longitudinal end, wherein each of the arm portions is fixed in the region of its first longitudinal end to the backrest and in the region of its second longitudinal end of the engaging piece and the further engaging piece. This allows efficient implementation and operation of the actuator. In this case, the arm sections of the actuator preferably comprise at the first longitudinal ends respectively a fixing structure with a cross-sectionally T-shaped insertion plug and a locking pin and the backrest two each one of the insertion pin associated insertion opening with a Einbringbereich and a fixing region and two each one of the locking pin associated locking openings.

The insertion openings of the backrest are preferably dimensioned in the insertion region such that the insertion pins of the fixing structure of the arm sections of the actuator pass through and dimensioned in the fixing region such that neck sections of the insertion pins of the fixing structure of the arm sections of the actuator fit through and head sections of the insertion pins of the arm sections of the actuator do not pass through. The term "neck portion" may refer in particular to the stem portion of the T-shape in connection with the T-shaped cross-section of the insertion pin. Similarly, the term "head portion" may refer in particular to the crown portion of the T-shape in connection with the insertion T-shaped cross-section pin. In other words, the insertion pins may each comprise a neck or stem portion and a head or crown portion. In this case, the insertion opening may be shaped and dimensioned such that the head section passes through its insertion area but not through its fixing area. The insertion pin can thus be performed for mounting the actuator to the backrest through the Einbringbereiche the insertion openings. Thereafter, they can be slid along the insertion openings until they extend through the fixing areas. At this point, the head portions can not be moved out of the insertion openings and the actuator is attached to the backrest.

The locking pins of the fixing structure of the arm portions of the actuator are preferably arranged in the locking openings when the insertion pins of the fixing structure of the actuator are arranged in the fixing of the insertion openings of the backrest, and in which the locking pins of the fixing structure of the actuator are arranged outside the locking openings, when the Insertion pins of the fixing structure of the actuator are arranged in the insertion areas of the insertion openings of the backrest. Such a configuration enables the locking pins to hold the insertion pins in the fixing regions of the insertion openings. In this way it can be prevented that the Insertion pin from the insertion openings and the actuator is removed from the backrest.

Preferably, the Tragarmfassung the backrest is quasi-sleeve-shaped, wherein the support arm of the backrest support is inserted into the Tragarmfassung the backrest. Such a sleeve-shaped Tragarmfassung can allow a stable and efficient installation of the backrest on the backrest support. Also, the backrest mounted on the backrest support can be moved along the support arm so well guided. In versions with backrest support with two support arms, the further support arm mount is advantageously also sleeve-shaped.

The latching row of the support arm of the backrest support is preferably located in the interior of the Tragarmfassung, the Tragarmfassung the backrest has a trained adjacent to the locking row of the support arm of the backrest support engagement and the actuator is mounted on the Tragarmfassungen the backrest that the engaging piece of the actuator in the blocking position extend through the engagement opening of the Tragarmfassung the backrest therethrough. This can allow efficient simple construction.

Preferably, the actuator is made of a plastic. Such an actuator can be produced inexpensively precise. In addition, it can thus have the required elasticity.

The backrest device preferably has a blocking device which prevents the backrest from being removed from the backrest support or being removable when the adjustment element is in the movement position. The blocking may have a movement limit for the actuator and a stop. In this case, the movement limitation may comprise a structure which limits a scope of movement of the actuator. This can be achieved that the engaging piece can be pulled to a predefined position or position from the detent row and not further. The stop may be placed adjacent to the detent row or at one end thereof. It can be dimensioned so that the engaging piece of the actuator does not pass it in any operating position of the actuator. Thereby, he can prevent the actuator and the associated backrest support is removed from the backrest support. Such Blocking can prevent incorrect operation of the backrest device and in particular an unintentional removal of the backrest from the backrest support.

Brief description of the drawings

Fig. 1

eine perspektivische Explosionsansicht eines Ausführungsbeispiels einer erfindungsgemässen Rückenlehneneinrichtung;

Fig. 2

eine perspektivische Ansicht der Rückenlehneneinrichtung von Fig. 1;

Fig. 3

eine Querschnittsansicht der Rückenlehneneinrichtung von Fig. 1 in einer unteren Blockierstellung;

Fig. 4

eine perspektivische Querschnittsansicht der Rückenlehneneinrichtung von Fig. 1 in der unteren Blockierstellung;

Fig. 5

eine Querschnittsansicht der Rückenlehneneinrichtung von Fig. 1 in einer unteren Bewegungsstellung; und

Fig. 6

eine Querschnittsansicht der Rückenlehneneinrichtung von Fig. 1 in einer oberen Bewegungsstellung.

Further advantageous embodiments of the invention will become apparent from the following description of embodiments of the invention by means of the schematic drawing. In particular, the backrest device according to the invention will be described in more detail below with reference to exemplary embodiments with reference to the attached drawings. Show it:

Fig. 1

an exploded perspective view of an embodiment of a backrest device according to the invention;

Fig. 2

a perspective view of the backrest device of Fig. 1 ;

Fig. 3

a cross-sectional view of the backrest device of Fig. 1 in a lower blocking position;

Fig. 4

a perspective cross-sectional view of the backrest device of Fig. 1 in the lower blocking position;

Fig. 5

a cross-sectional view of the backrest device of Fig. 1 in a lower position of movement; and

Fig. 6

a cross-sectional view of the backrest device of Fig. 1 in an upper position of movement.

Way (s) for carrying out the invention

Certain terms are used in the following description for convenience and are not meant to be limiting. The words "right,""left,""bottom," and "top" refer to directions in the drawing to which reference is made. The terms "in", "out", "below", "above", "left", "right" or the like will be used to describe the arrangement of designated parts to each other, the movement of designated parts to each other and the directions toward or away from geometric center of the invention and named parts thereof as shown in the figures used. These relative relative terms also include other positions and orientations than those shown in the figures. For example, when a part shown in the figures is turned over, elements or features described as "below" are then "above". The terminology includes the words expressly mentioned above, derivatives thereof and words of similar meaning.

To avoid repetition in the figures and the associated description of the various aspects and embodiments, it is intended that certain features be considered to be common to various aspects and embodiments. The omission of an aspect in the description or a figure does not suggest that this aspect is lacking in the associated embodiment. Rather, such omission may serve the purpose of clarity and prevention of repetition. In this context, the following definition applies to the entire further description: If reference signs are included in a figure for the purpose of clarity of drawing, but are not mentioned in the directly related descriptive text, reference is made to the explanation thereof in the preceding description of the figures. If reference signs are also mentioned in the description text directly related to a figure, which are not included in the associated figure, reference is made to the preceding and following figures. Like reference numerals in two or more figures indicate similar or like elements.

Fig. 1 shows an embodiment of an inventive backrest device 1 for an office chair. The backrest device 1 comprises a backrest support 3, a backrest 2 and an actuator 4 or a button. The backrest support 3 has two parallel and vertically oriented support arms 31. The support arms 31 go via two angle pieces in each case a horizontally aligned connecting arm 32. The two parallel connecting arms 32 are connected to one another via a transverse strut 34 and fixed to one another. At their angle ends facing away from the longitudinal ends of the connecting arms 32 are each equipped with a mounting structure 33, via which the backrest support 3 can be attached to a seat support or a base member of the office chair. The two vertical support arms 31 of the backrest support 3 are each equipped with a row of teeth 311 running from bottom to top and oriented forwards as a row of rest. The rows of teeth each have a plurality of teeth 312 spaced by gaps. Above adjacent to the row of teeth 311, the support arms 31 each have a stop 313 of a blockage.

The backrest 2 comprises a frame 21, in which a leaning structure, for example a textile substrate, can be stretched flat. In addition, it has two parallel and vertically oriented Tragarmfassungen 22, which are mounted between two horizontal sections. The Tragarmfassungen 22 are quasi-sleeve-shaped and have an interior. At a front side, the two Tragarmfassungen 22 are analogously equipped with three vertically spaced openings through which the interior of the associated Tragarmfassung 22 is accessible. In particular, the Tragarmfassungen 22 each have a lower rectangular engagement opening 221, an upper, also rectangular but smaller sized locking opening 223 and a middle insertion opening 222. The insertion openings 222 are each formed with a lower rectangular insertion region 2221 and a fixing region 2222 running upwards from the latter in a slot-like manner.

The actuator 4 is formed in one piece and comprises two parallel and vertically aligned arm portions 41, each having an upper first longitudinal end 411 and a lower second longitudinal end 412. The two arm portions 41 are connected via a gripping portion 42 with each other so that corresponding to the distance of the Tragarmfassungen 22nd or the support arms 31 are spaced from each other. Near their second longitudinal ends 412, the two arm portions 41 are each provided with an engaging nose 413 extending in the direction of the backrest 2 as an engaging piece.

Im in Fig. 2 shown assembled state, the support arms 31 of the backrest support 3 are inserted from below into the two Tragarmfassungen 22 of the backrest 2. In this case, the support arms 31 are arranged in the interiors of the Tragarmfassungen 22. The actuator 4 is attached to the backrest 2 from the front, as described in more detail below, and cooperates with the support arms 31 as described in greater detail below.

FIG. 3 and FIG. 4 show the backrest device 1 in a lower blocking position. In this case, the arm portions 41 of the actuator 4 are in each case at one of the Trätzfassungen 22 of the backrest 2. Near their first longitudinal ends 411, the arm sections 41 are each provided with a locking pin 415 extending in the direction of the support arm socket 22, which engages in the locking opening 223 of the associated support arm socket 22. In to Einschieböffnung 222 of the associated Tragarmfassung 22 corresponding position, the arm portions 41 are also with each one in the direction of Tragarmfassung 22 extending insertion pin 414 equipped. The locking pins 415 and the insertion pins 414 together form a fixing structure of the actuator 4.

As in Fig. 4 3, the plug-in pins 414 are formed in a horizontal cross-section quasi T-shaped and each comprise a head portion 4142 and a neck portion 4141. For mounting the actuator 4 on the backrest 2, the insertion pins 414 into the Einbringbereiche 2221 of the insertion openings 222 of the Tragarmfassungen 22nd presses. For this purpose, the arm portions 41 must be bent. The head portions 4142 are arranged in the interior of the Tragarmfassungen 22 and the neck portions 4141 extend through the insertion openings 222 to the outside. Then, the actuator 4 is pushed upward until the neck portions 4141 of the insertion pins 414 of the arm portions 41 in the fixing portions 2222 of the insertion openings 222 of the support arms 22 is located. The head portions 4142 are still arranged in the interior of the support arms 22 and their size they can not pass through the fixing portions 2222 of the insertion openings 222 to the outside. The arm portions 41 of the actuator are thus fixed to the Tragarmfassungen 22 of the backrest 2. At the same time, the locking pins 415 of the arm portions 41 are snapped into the locking openings 223 of the Tragarmfassungen 22. As a result, a displacement of the actuator 4 is blocked or blocked down and the actuator 4 is fixedly locked to the backrest.

In the in the Fig. 3 and the Fig. 4 shown engagement position 413 of the arm portions 41 of the actuator 4 through the engaging openings 221 of the Tragarmfassungen 22 of the backrest 2 into the rows of teeth 311 of the support arms 31 of the backrest support 3. In particular, the engaging lugs 413 are each in the gap between the bottom two teeth 312 arranged. The backrest 2 is thus in a lowermost position on the backrest support 3. A vertical movement of the backrest 2 relative to the backrest support 3 is blocked by the actuator 4.

Fig. 5 shows the backrest support 1 and its actuator 4 in a movement position. The gripping portion 42 is manually pulled away from the Tragarmfassungen 22 of the backrest 2. Since the arm portions 41 of the actuator 4 as described above fixed to the Tragarmfassungen 22 are locked, the actuator 4 elastically bent to the left. The engagement lugs 413 are brought out of engagement with the rows of teeth 311 of the support arms 31 of the backrest support 3. The Tragarmfassungen 22 can now be moved in the vertical direction along the support arms 31. This allows the entire backrest 2 to move vertically relative to the backrest support 3 and an altitude of the backrest 2 can be adjusted. The upper end portions of the support arms 31 are dimensioned so that the Tragarmfassungen 22 can not be lifted upwards from the Lehneträger 3.

As in Fig. 4 and Fig. 5 a lower transverse bar of the frame 21 of the backrest 2 clearly defines a movement or bending of the actuator 4. In particular, the gripping section 42 strikes against the transverse bar when it is moved out of the blocking position to a predefined extent. The crossbar thus forms together with the gripping portion 42 a movement limitation of the blockage. In addition, the projections 313 respectively project beyond the teeth 312 of the associated row of teeth 311 to the left or to the extent that the associated engagement piece 413 of the actuator 4 strikes against it when the backrest 2 is moved upwards in the release position. It is thus achieved that the engagement pieces 413 can each be pulled to a predefined position or position from the associated latch row 311, in which they are moved sufficiently far to the left that they can pass the associated row of teeth 311 but not the associated projection 313. The backrest 2 is thus secured by means of the lock on the backrest support 3 and can not be inadvertently removed from this.

In Fig. 6 the back support 1 is shown in an upper blocking position. In this case, the gripping portion 42 of the actuator 4 is released again, so that due to the inherent elasticity of the actuator 4, the arm portions 41 rest against the Tragarmfassungen 22. The engagement lugs 413 of the arm portions 41 engage through the engagement openings 221 of the Tragarmfassungen 22 into the rows of teeth 311 of the support arms 31 of the backrest support 3. In particular, the engagement lugs 413 are each arranged in the gap between the upper two teeth 312. The backrest 2 is thus in an uppermost position on the backrest support 3. A vertical movement of the backrest 2 relative to the backrest support 3 is blocked by the actuator 4.

Although the invention has been shown and described in detail by means of the figures and the associated description, these depictions and these are detailed Description is illustrative and exemplary in understanding and not limiting as the invention. In order not to transpose the invention, in some instances, well-known structures and techniques may not be shown and described in detail. It is understood that those skilled in the art can make changes and modifications without departing from the scope of the following claims. In particular, the present invention covers other embodiments with any combinations of features that may differ from the feature combinations explicitly described.

The present disclosure also includes embodiments having any combination of features that are mentioned or shown above or below various embodiments. It also comprises individual features in the figures, even if they are shown there in connection with other features and / or are not mentioned above or below. Also, the alternatives of embodiments and individual alternatives described in the figures and the description may be excluded from the subject matter of the invention or from the disclosed subject matter. The disclosure includes embodiments which exclusively comprise the features described in the claims and in the exemplary embodiments as well as those which include additional other features.

Furthermore, the term "comprising" and derivatives thereof do not exclude other elements or steps. Likewise, the indefinite article "a" or "a" and derivatives thereof does not exclude a variety. The functions of several features listed in the claims may be fulfilled by a unit or a step. The terms "substantially", "approximately", "approximately" and the like in connection with a property or a value in particular also define precisely the property or exactly the value. The terms "about" and "approximately" in the context of a given numerical value or range may refer to a value or range that is within 20%, within 10%, within 5%, or within 2% of the given value or range.

Claims (15)

Backrest device (1) for a chair and in particular an office chair which has a backrest support (3) with a support arm (31), a backrest (2) mounted on the support arm (31) and an actuator (4) adjustable between a blocking position and a movement position , in which the support arm (31) of the backrest support (3) is equipped with a latching row (311), the actuator (4) is connected to the backrest (2) and has an engagement piece (413), engages in the blocking position, the engaging piece (413) of the actuator (4) in the latching row (311) of the support arm (31) of the backrest support (3), so that a movement of the backrest (2) along the support arm (31) of the backrest support (3 ) is locked, and in the movement position the engagement piece (413) of the actuator (4) out of engagement with the detent row (311) of the support arm (31) of the backrest support (3), so that the backrest (2) along the support arm (31) of the backrest support (3 ) is movable, characterized in that
the actuator (4) is made in one piece from an elastic material, wherein it is elastically deformed in the movement position by a force, so that the engagement piece (413) of the actuator (4) from the detent row (311) of the support arm (31) of the backrest support (3) is moved. A backrest device (1) according to claim 1, wherein the backrest (2) comprises a support arm socket (22), the backrest (2) being mounted on the back support (3) by the support arm (31) of the back support (3) in the support arm socket (22) of the backrest (2) is mounted. Backrest device (1) according to claim 1 or 2, in which the backrest support (3) is equipped with a further support arm (31) on which the backrest (2) is mounted, wherein the further support arm (31) is equipped with a further latching row (311), the actuator (4) has a further engagement piece (413), in the blocking position, the further engagement piece (413) of the actuator (4) engages in the further latching row (311) of the further support arm (31) of the back support (3), in the movement position, the further engagement piece (413) of the actuator (4) out of engagement with the further latching row (311) of the further support arm (31) of the backrest support (3), and the actuator (4) is elastically deformed in the movement position by the force such that the further engagement piece (413) of the actuator (4) is pulled out of the further latch row (311) of the further support arm (31) of the back support (3). Backrest device (1) according to Claims 2 and 3, in which the backrest (2) has a further support arm socket (22), wherein the further support arm (31) of the back support (3) is mounted in the further support arm socket (22) of the backrest (2) is. Backrest device (1) according to one of the preceding claims, wherein the actuator (4) has a gripping portion (42) for manual actuation of the actuator (4). Backrest device (1) according to one of claims 3 to 5, wherein the actuator (4) comprises two arm portions (41), on each of which one of the engagement piece (413) and the further engagement piece (413) is arranged. Backrest device (1) according to claim 5 and 6, wherein the gripping portion (42) of the actuator (4) whose two arm portions (41) interconnects. Backrest device (1) according to claim 6 or 7, wherein the arm portions (41) of the actuator (4) each have a first longitudinal end (411) and a second longitudinal end (412), wherein each of the arm portions (41) in the region of its first longitudinal end (411) is fixed to the backrest (2) and has in the region of its second longitudinal end (412) one of the engagement piece (413) and the further engagement piece (413). Backrest device (1) according to claim 8, wherein the arm sections (41) of the actuator (4) at the first longitudinal ends (411) each comprise a fixing structure with a cross-sectionally T-shaped insertion pin (414) and a locking pin (415) and in which the backrest (2) has two insertion openings (222) each assigned to one of the insertion pins (414), having an insertion area (2221) and a fixing area (2222) and two locking openings (223) each assigned to one of the locking pins (415). Backrest device (1) according to claim 9, wherein the insertion openings (222) of the backrest (2) in the insertion region (2221) are dimensioned such that the insertion pins (414) of the fixing structure of the arm sections (41) of the actuator (4) pass through and in the fixing region (2222) are dimensioned so that neck portions (4141) of the insertion pins (414) of the fixing structure of the arm portions (41) of the actuator (4) pass through and head portions (4142) of the insertion pins (414) of the arm portions (41) of the actuator (4) do not pass through. Backrest device (1) according to claim 10, in which the locking pins (415) of the fixing structure of the actuator (4) are arranged in the locking openings (223) when the insertion pins (414) of the fixing structure of the actuator (4) in the fixing areas (2222). the insertion openings (222) of the backrest (2) are arranged, and in which the locking pins (415) of the fixing structure of the actuator (4) outside the locking openings (223) are arranged when the insertion pin (414) of the fixing structure of the actuator (4) in the introduction areas (2221) of the insertion openings (222) of the backrest (2) are arranged. Backrest device (1) according to one of the preceding claims, wherein the Tragarmfassung (22) of the backrest (2) is quasi sleeve-shaped, wherein the support arm (31) of the backrest support (3) in the Tragarmfassung (22) of the backrest (2) inserted is. The backrest device (1) according to claim 12, wherein the latching row (311) of the support arm (31) of the backrest support (3) is located inside the support arm mount (22), the support arm mount (22) of the backrest (2) being adjacent to Locking row (311) of the support arm (31) of the backrest support (3) formed engaging opening (221) and the actuator (4) is mounted on the Tragarmfassung (22) of the backrest (2) that the engaging piece (413) of the actuator (4) extends in the blocking position through the engagement opening (221) of the Tragarmfassung (22) of the backrest (2) therethrough. Backrest device (1) according to one of the preceding claims, wherein the actuator (4) is made of a plastic. Backrest device (1) according to one of the preceding claims, comprising a lock (21, 313, 413, 42) which prevents the backrest (2) from being removed from the backrest support (3) when the actuator (4) moves in the backrest Movement position is located.

Images