EP1911374B1 - Seat with ergonomic backrest - Google Patents

Description

The invention relates to a passenger seat with a backrest part, which conforms ergonomically to the spine of a user.

State of the art:

In working chairs and office chairs so far the mobility of the seat and the backrest against each other much, but paid little attention to the mobility of the back part in itself. The backs were therefore far mostly rigid support surfaces, which were anatomically shaped and also often padded. Padding was occasionally replaced by taut textiles, such as woven and knitted fabric, which conformed to the shape of the back.

From the prior art it is known to pivotally attach a backrest about a pendulum axis to a support. Such non-adaptable to the back shape backrests are thanks to the pivoting about a pendulum axis above and below the pendulum axis on the back. The back can assume different positions without losing contact with the backrest.

In recent times, the mobility of the back part in itself paid more attention. This mobility is intended to support different postures of the user practically over the entire length of the spine - regardless of the spine waveforms. For example, office chairs have come onto the market, the backs of which adapt to the shape of the back when under stress.

From the US-A-2005/0275263 is a seat, in particular a vehicle seat known, which has a rigid backrest support, at the upper end of a flexible back shell is hinged. The back shell has a flexible boss area and is biased by a spring. The spring curves the back shell, especially in the boss area. By loading the back shell this is stretched in the boss area. At the lower end of the back shell is guided by a trapezoidal hinged pair of levers or a backdrop to the by a Load arising increase in distance between the upper and the lower end of the back shell can.

It is also known a chair whose back shell has a neck support. In the neck support, the back shell is hinged to a back support. At the lower end of the back shell, a lever arm is formed, which is perpendicular to the back shell and is articulated at its spaced from the back shell end on the back support. By pressure on the back shell this is curved in the chest area, while the lever arm and the head rest are pivoted in opposite directions. The spring force of the backrest shell counteracts such a curvature.

In the chairs described, the back, so long as it is based on the entire back of the backrest, supported so that the boss area and the Brustbereichsululde adapt to the circumstances of the leaning back. The back is evenly supported and yet has a freedom of movement, so that a losdosierender back is supported as well as a hunchback.

From the interim publication of EP 1 905 326 is known a backrest unit for use on a wheelchair. This has a backrest in moldable material, in particular according to the US Pat. No. 7,032,971 , The backrest is hinged at an upper and a lower connection point to a customizable support. This support is adaptable so that the running from top to bottom curve shape of the backrest and can be fixed in the selected position. In this way, the backrest can be adapted to a back shape. In order to achieve a versatile adjustment possibility, a plurality of horizontal pivot axes between lever arms of the support are provided. The support can be described as a four-bar support in which joints are formed between three of the rods and between the ends of these three rods and the backrest, which can be fixed in a desired position. The backrest unit is a total of about a horizontal fourth rod, which forms a pendulum back axle, pivotable. This pendulum back axle is formed between the upper and the lower joint. The backrest unit can be pivoted about this pendulum back axle, in order to be fixed in a certain pivot position.

A disadvantage of these chairs is that the adaptation of the support form to the back shape can take place only within narrow areas. It is therefore necessary that the user of the chair sits correctly on the seat surface.

Object of the invention:

It is an object of the invention to provide a passenger seat with an ergonomically cling backrest part, the construction of which is inexpensive to implement. The adjustment range of the support form of the backrest part should be extended compared to the prior art and can compensate for a deviation from an ideal sitting position.

Solution of the problem according to the invention:

The inventive solution to this problem is achieved by a person seat according to the independent claim 1.

A chair according to the invention or a person seat naturally has a support and a seat surface. Next he has at least one on the support Supported support part for supporting a backrest part. It also has the backrest part which is connected to the support part at at least two connection points spaced apart from one another in the backbone direction. The connection points are therefore formed between the support part and the backrest part, namely at least one in an upper region and at least one in a lower region. The backrest part comprises a molded part which, between a first backrest end close to the seat surface and a second, upper backrest end spaced apart from it in the backbone direction, defines a backbone anatomically curved support form with a convexly curved boss area and a concavely curved chest area.

In such a person's seat, the molded part and thus the curved support shapes of the backrest part can be plugged or bent under the influence of a load acting on the backrest part, changing load by a chair user about bending axes directed perpendicularly to the backbone direction. Furthermore, the backrest part is mounted on the support part at at least one connection point in such a way that the first back end and the second backrest end can extend away from one another during stretching of the support form and approach one another during curvature of the support form. These changes in distance between the backrest ends of the backrest part therefore occur under the influence of the leaning pressure of the user.

According to the invention the object is achieved in that the carrier part is mounted on the support about a horizontal pendulum axis, which is formed between the lower connection point and the upper connection point, pivotally. Thanks to the backrest is formed together with the support member as a pendulum back, a balance of the seat position is done on this pendulum back. The adjustment of Bossbümmung and chest curvature is therefore largely independent of the seating position of the chair user. The support pressures on the backrest are balanced at all times, so that the support form is under uniform pressure and can therefore optimally adapt to the shape of the back. The adaptability of the support form is thus relieved of the task of correcting a seating position. As a result, the support form completely adapts to a back posture occupied by the user and lies in every sitting position over the entire extent extending in the backbone direction on the back and makes its movements and shape changes by changing the shape of the support form.

Conveniently, the backrest part is mounted on at least one connection point in the backbone direction against a spring force variable position. The spring element may form the backrest part or the molded part itself. It can also be an independent part of it. Such acts independently of the spring force of the molding on the distance between the backrest ends.

There are basically two opposing ways to initiate the spring force. A first type is that the spring force stretches the molding. In this case, the molding is bendable in the chest area by the load. A second type is that the molded part in the boss area is stretchable by the load and the spring force curves the molded part.

When the molded part is stretched by the spring force, the backrest part, in particular the molded part in the convexly curved Bossbereich can be supported on a tension element, which tension element is stretched between the two connection points. The tension element does not have to be fastened directly to the connection points, but merely to ensure that the connection points are essentially in a maximum distance defined by the tension element. This spacing restriction may also apply the tension member to the ends of the backrest member when attached to these ends.

When the backrest part is stretched by the spring force, it is advantageous if the molded part in the convexly curved boss area is made stiffer with respect to pressure on the backrest part than in the concavely curved chest area. As a result, the chest area deforms more and the boss remains supported even under increased pressure.

When the user presses on the concave curvature of the thoracic spine supporting portion of the backrest portion, the backrest portion is curved and the length of the backrest portion is reduced. Due to the flexibility of the backrest part, the position of the boss can be corrected by pressure on the boss and chest area, whereby the distance between the ends of the backrest part does not necessarily have to change when the boss changes position.

It may also be the molded part formed and the backrest part may be mounted on the support member such that even a burden of Bossbereichs against the The backrest part acts exciting spring force and leads to a reduction of the radius of curvature in the chest area.

In particular, the following statements are proposed, which lead to a shortening of the distance between the back ends when the stretched backrest part is loaded:

The backrest part, in particular the molded part, is supported in the convexly curved boss area on a tension element between the two fastening points. The tensioning element interconnecting the fastening points is thereby deflected under load in Bossbereich. This deflection causes an approximation of the two attachment points. As a result, the curvatures of the molded part must have lower radii under load than with an unloaded backrest part. This causes the boss area to conform to the back shape of the backrest and not flatten.

In the same or also another embodiment, the molded part in the convexly curved boss area is made stiffer with respect to pressure on the backrest part than in the concavely curved chest area. This rigidity difference, given the conditions of the under-mold, results in pressure on the boss resulting in a depression of the concave bumps following the boss and therefore a reduction in the radius of curvature in the chest area. Pressure on the boss therefore causes back pressure in the shoulder area, so that adjusts a pressure equalization over the length of the back.

In a third embodiment, the molding is pivotally mounted in at least one of the attachment points about an axis behind the backrest part, so that a caused by a load between the attachment points pivoting of the backrest part in this attachment point leads to a shortening of the distance between the backrest ends. This embodiment can be divided into two subtypes. In the first subspecies, the molded part is curved by the spring element, so that a pressure on the backrest can lead to an extension of the boss area. In the second subspecies, the molded part is stretched by the spring element, so that a pressure on the chest area can lead to a shortening between the backrest ends. Thanks to the articulation behind the backrest part is achieved that an extension and shortening of the distance between the backrest ends can occur.

The positionally variable in the backbone direction connection between the backrest part and the support part, be this connection by pivoting a lever or by sliding along a link variable in position, may be provided at the upper or lower joint. It can also be provided both at the upper and the lower joint.

Basically, there are two ways to bias the backrest part by means of a spring. In a first embodiment, the backrest part transmits compressive forces to the carrier part in the backbone direction. The backrest part is therefore sensitive to pressure on the boss and is thereby stretched. Pressure on the concave portion of the backrest part also tends to lead to an extension of the convex area, so the boss.

In a second embodiment, the backrest part transfers tension to the support part in the backbone direction. The backrest part therefore reacts sensitively to pressure on the concave area and reacts by reducing the radius of curvature in the concave area, resulting in a shortening of the distance between the backrest ends and / or an enlargement of the radius of curvature in the convex boss area.

The displacement is preferably performed such that the backrest part is pivoted at a displacement with or with respect to the connection point at the connection point about an optionally imaginary pivot axis directed parallel to the bending axes. This can be done by a curved guide rail or by a displaceable pivot axis in connection with the pivoting force-enforcing means at the displacement point. Advantage of this pivoting is that the curvature of the backrest part is controlled as a function of the pressure load and therefore specifically defined, for example, by the curvature of a guide rail. As a result, the behavior of the backrest part can be planned and designed by the formation of the pivoting defining guide means.

As such guiding means, in one embodiment, a curved guide rail and a sliding part cooperating with the guide rail and displaceable along the curvature of the guide rail are preferred. The guide rail may be formed on the backrest part or on the support part. The Sliding part should follow the curvature and thereby transfer the change in angle of curvature on the backrest part, or if the guide rail is present on the backrest part, forcibly swivel the guide rail about the center of the radius of curvature. This has the advantage of being able to plan the sequence of movements, since the plannable curvature of the guide rail is transferred to the movement of the backrest part.

If the backrest part is tensioned in the backbone direction, the two connection points are advantageously held together by a traction means. The traction means defines the distance between the two connection points in the unloaded basic position. The backrest part can itself serve as a traction device. But it can also be provided separate from the backrest part traction means. The traction means may be formed variable in length so as to achieve adjustability of the curvature of the backrest part in the normal position.

The backrest part may be in one place, e.g. be supported at the boss, or at several points on the traction device. Pressure on this point causes in the consequence a shortening of the distance of the attachment points of the traction means on the carrier part, or a shortening of the distance between the connection points between the backrest part and the carrier part. Pressure on the supported boss thus does not necessarily cause an extension of the convex boss area, but a shortening of the distance between the connection points and thereby a reduction of the radii of curvature of the curved parts of the backrest part. This leads to a pressure equalization between the lumbar region (boss), the lower end region (pelvis, pelvic edge) and the upper end region (thoracic spine) of the double S-shaped curved backrest part.

Regardless of the embodiment, a pendulum behavior of the backrest part is achieved by the support member is mounted pivotably about a horizontal pendulum axis on the support. As a result, a pressure equalization between the pressures in the upper and in the lower region of the backrest part is established in a manner known per se. This pressure equalization, however, has the consequence that the effect of the form of the back which adapts to the shape of the back is maximally utilized.

The biasing of a positionally adjustable in the backbone attachment of a flexible backrest part allows one of a frame and a stretched on the frame support fabric existing backrest part in itself flexible and form a total conforming to the back shape. Conveniently, For this purpose, the side parts of the frame are flexible. The flexibility of the side parts may be limited in some areas by a defined range of motion between frame members from which the side panels are constructed. This allows a predetermination of the possible support forms that can take the backrest part.

In such a textile-covered backrest part, the upper and lower end portion of the frame are biased by spring means expediently away from each other. But they can also be biased towards each other, so that the side parts of the frame in addition to the pressure, which is caused by the train in the textile covering in the side panel, also have to absorb the pressure generated by the spring means.

The two side parts are preferably supported by means of several tendons against each other. These extend horizontally or diagonally from a frame member of the left side part to a frame member of the right side part. These tendons are used to maintain the distance between the two side parts and therefore the relief of the joint areas between adjacent frame members of a side part.

Fig. 1

zeigt eine schematische Seitenansicht eines Stuhles einer Ausführungsart mit einer durch Federmittel gekrümmten Rückenlehne, und zwar in Figur 1A in einer Grundstellung und in Figur 1B unter Belastung.

Fig. 2

zeigt eine schematische Seitenansicht eines Stuhles einer zweiten Ausführungsart mit einem unter Zugspannung stehenden, auf gefederten Schwenklagern gelagerten Lehnenteil, und zwar in Figur 2A in einer Grundstellung und in Figur 2B unter Belastung.

Fig. 3

zeigt eine perspektivische Skizze einer erfindungsgemässen Rückenlehne eines Stuhls, bei welcher das Lehnenteil durch einen Rahmen und ein darauf gespanntes Textil gebildet ist.

Brief description of the figures:

Fig. 1

shows a schematic side view of a chair of an embodiment with a curved by spring means backrest, in Figure 1A in a basic position and in FIG. 1B under pressure.

Fig. 2

shows a schematic side view of a chair of a second embodiment with a tensioned, mounted on sprung pivot bearings backrest part, in FIG. 2A in a basic position and in FIG. 2B under pressure.

Fig. 3

shows a perspective sketch of a novel backrest of a chair, in which the backrest part is formed by a frame and a textile stretched thereon.

This in FIG. 1 illustrated backrest part 11 is in a basic position according to Figure 1A anatomically shaped. That is, it is a convex boss 13 designed as a lumbar support, below the boss 13 is a concave portion 15 is formed to support the pelvis or pelvic edge of a user. Above the boss is 13 a concave portion 17 is formed for supporting the thoracic spine and the shoulder regions of a user.

In an upper and a lower region of the backrest part 11 a respective storage of the backrest part on the support part 21 is formed. These define the upper joint 20 and the lower joint 30 of the backrest part 11 with the support part 21. At the upper joint 20, the backrest part 11 is simply hinged to the support member 21 about a horizontal axis. At the lower connection point 30, the backrest part is articulated on a lever 41, which in turn is articulated on the support part. The lever 41 is pulled with a spring 43 in an upper position. By loading the backrest part 11, the backrest part is stretched. The lever moves against the spring force from the upper position to a lower position. For the provision in the basic position, a spring action can be used, which inherits the backrest part 11, or, as shown, a separate from backrest part and molding spring 43 are used.

The support part 21 is rigid. It is articulated about a pendulum axis on the support 37. The pendulum axis 35 is located in an area around a lower, the distance between the lower to the upper junction 20, 30 third point. The pivoting movement about the pendulum axis is, as is known in conventional pendulum back, cushioned.

At the in FIG. 2 illustrated embodiment, there is a tension bias between the joints 20,30. The support member 21 is resilient and pulls the two connection points 20, 30 apart. This force counteracts a tension band 24 which, for example, connects the two connecting points 20, 30 - or two other points of the carrier part 11 which are spaced apart from the connecting points - to one another.

The backrest part 11 can be deformed as a result of an action of the back of a user. A deformation, since the distance between the two connection points 20, 30 can not be larger, but only smaller, only lead to a reduction of the radius of curvature of a curvature of the backrest part. As a result, the joints are approximated or another radius of curvature is increased. If the joints approach each other, the tension band 24 becomes loose. It may be the drawstring but also against the backrest part 11 simply or repeatedly supported. in the Example according to FIG. 2 a support 26 of the boss 13 is provided. Due to the deformation of the backrest part 11, the boss is pushed back and the tension band 24 is bent out of the extended position at a defined point. The deflection of this point can only be done in one measure, as is made possible by the shortening of the distance between the interconnected by the tension band points of the support member 21.

In FIG. 2A the backrest part is shown in the basic position. In FIG. 2B it is shown charged. The concave support form for the thoracic spine is more curved than in the basic position. The boss 13 is pushed back. The lower and the upper end of the backrest part are pushed forward due to the shortening of the distance between the ends of the arcuate, elastic support part 21 and due to the pivoting in the connection points. The backward movement of the boss is limited by the tension band 24, so that the shortening of the distance between the connection points leads to a reduction of the radii of curvature in both the concave and in the supported convex support areas.

In FIG. 3 a particular application of the second embodiment is shown. However, a corresponding application of the first embodiment is also possible. The particular embodiment consists in that the backrest part 11 consists of a frame 25 with flexible side parts 27 and a textile 29 spanned on the frame. The side parts are divided into frame members 31. These frame members are movable against each other to a limited extent. Between two frame members 31, a kind of hinge joint is formed, and this is movable between two stop positions. The hinges are movable around horizontally lying bending axes.

As textile 29, woven or knitted fabrics come into question. These are connected to the frame 25, wherein the frame biases the textile in two directions. Since the frame 25 is three-dimensionally shaped, there is also a three-dimensional support shape of the textile 29.

By the support part 21 of the upper and the lower frame bar 33 are pressed apart elastically. The tensile forces are absorbed by the side parts 27. The side panels are therefore biased. The frame members 31 strike in this basic position to each other so that the radii of curvature are the largest. By loading the backrest part can These radii are reduced, whereby the upper and the lower frame rod 33 are approximated to each other.

If the side parts are under pressure due to the bias, the frame members 31 abut each other so that the radii of curvature are the smallest. By loading these are then enlarged.

In the FIGS. 1 to 3 the chair back with backrest part 11 and support member 21 are formed as pendulum back. They are pivotable about a pendulum axis 35 on the support 37. This pendulum axis 35 is arranged after about a third on the route from the lower to the upper junction 20, 30. The pivoting movement about the pendulum axis is cushioned in a known manner.

This backrest construction is suitable for office chairs. Thanks to the upper and lower support of the backrest part, it can be assumed that this construction is also suitable for motor vehicle seats.

Claims (11)

1. Person seat with a support (37), at least one carrying part (21) resting on the support, a back rest part (11) placed on the carrying part and at least two junctures (20, 30) between the carrying part (21) and the back rest part (11), spaced from each other in spine direction, the back rest part (11) having at least one moulded part (11, 27) extending in spine direction, the moulded part causing that the back rest part forms between a first back rest end (10) and a second back rest end (12) spaced from this in spine direction an anatomically curved supporting form with a concave curved thoracic area (17) and a convex curved lumbar area (13), the moulded part (11, 27) being bendable or extendible under the action of a changing load on the back rest (11) about bending axles orientated perpendicularly to the spine direction, whereby the back rest part (11) is positioned on the carrying part (21) at the junctures (20, 30) in such a manner that the first back rest end (10) and the second back rest end (12) can move away from each other when the moulded part is being stretched and can come closer to each other when the moulded part is being bent and for which the carrying part (21) is positioned swivelling on the support (37) about a horizontal oscillating axle (35) placed between the lower juncture (30) and the upper juncture (20), characterized in that the swivelling movement about the oscillating axle is cushioned.
2. Person seat according to claim 1, characterized in that the back rest part (11) is positioned variable in position in spine direction against an elastic force at at least one juncture (20, 30).
3. Person seat according to claim 2, characterized in that the elastic force is fed by a spring element which acts onto the distance between the back rest ends independently from the elastic force of the moulded part.
4. Person seat according to claim 2 or 3, characterized in that the moulded part is bendable in the thoracic area (17) due to the load and that the elastic force stretches the moulded part (11, 27).
5. Person seat according to claim 2 or 3, characterized in that the moulded part is stretchable in the lumbar area due to the load and that the elastic force bends the moulded part (11, 27).
6. Person seat according to claim 5, characterized in that the back rest part, in particular the moulded part, rests in the convex curved lumbar area on a tension element (24), this tension element being tensioned between the two junctures (20, 30).
7. Person seat according to any of the claims 1 to 6, characterized in that the moulded part is configured stiffer in the convex curved lumbar area with respect to the pressure onto the back rest part (11) than in the concave bent thoracic area.
8. Person seat according to any of the claims 6 or 7, characterized in that a maximal stretching of the back rest part (11) is limited by the tension means (4).
9. Person seat according to any of the claims 1 to 8, characterized in that the back rest part (11) is made of a frame (25) and a supporting textile (29) tensioned on the frame.
10. Chair according to claim 9, characterized in that the side parts (27) of the frame (25) are configured flexible and define as moulded parts the shape of the lumbar area and of the thoracic area.
11. Chair according to claim 10, characterized in that the flexibility of the side parts (27) is limited areawise by a defined motion clearance between frame elements (31).

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