The invention relates to a backrest, in particular
an office chair, with two backrests and a lumbar support.
Chairs are often used in the office area
high seating comfort used. These enable this
in the home or rest position due to the practically vertical
Position of the backrest reliable support
the back of a user person. The shape of the leaning front
Outside contour of the backrest can here more
or less adapted to the typical S-shape of a spine
be. Also, alternatively or additionally, in the lumbar region
of the user's back a lumbar support
From the DE 20 004 948 A1
is a backrest with an adjustable lumbar support known to set a manually operable mechanism is provided. In particular, in conjunction with a so-called synchronous mechanism for synchronously adjustable inclination of the backrest and seat, the mechanical complexity is not negligible.
The invention is therefore based on the object, a backrest,
preferably for a chair, in particular for
an office chair, indicate that at the same time high
Comfort and low cost has a particularly effective lumbar support.
The object is achieved by
the features of claim 1. Advantageous embodiments and developments
are the subject of the dependent claims.
The backrest is initially made of two superimposed
arranged backrest portions formed on a backrest support
are held. The two backrest areas are in the lumbar area
the back of a user person articulated
connected with each other. The two backrest areas are expediently
each by rigid, substantially deformation resistant backrest cushion
educated. Here are suitably the two backrest areas
to form an S-shaped support or
Outer contour lean forward and gap back
arranged spaced apart. The lean or upholstery back
Release or gap contour allows in easier
and visually virtually invisible way the desired
Deformability between the two backrest areas at the same time
Deformation stiffness of the two backrest areas.
Backrest areas are under training on the backrest support
a four-link chain held articulated. The pivot points or axes
are suitably positioned in such a way
that two in the backrest longitudinal direction preferably against each other
vertically offset joints in the lower,
seat-facing area of the backrest front are provided while
the other two, also vertically offset in Lehnenlängsrichtung one above the other
positioned joints lean back on the backrest support
this is expediently a first joint
the effective in the manner of a four-link chain joint between
the upper backrest area and the lower backrest area and there
again formed in the area of the lumbar support. A second
Joint is conveniently between the lower
Backrest area and the (lower) support arm of the backrest support
educated. About this joint are those in the lordosis area
mutually connected backrest areas or backrest cushions lean underneath
held on the backrest support.
third joint of this four-joint chain or joint is
between the (lower) support arm and one at this
articulated (upper) backrest of the backrest carrier
educated. The fourth joint of the four-bar chain is then expediently
between the upper backrest area and the (upper) backrest link
formed by the backrest wearer. About this top
Joint are the two backrest areas and backrest cushions on the upper side
articulated on the backrest support, in particular on the backrest support
quasi hung up.
Functional principle of the four-bar chain is thus realized by
between the articulated backrest support on the one hand and the
flexible connection between the two backrest areas on the other hand the
the four joints connecting members themselves each
are rigid. The thus formed between the two backrest areas
flexible area is at the height of about the lordosis
the operator and forms there the flexible lumbar support.
As a result of an action on the backrest in the transition region between the two backrest areas by the operator takes the degree of curvature of the flexible lumbar support, which is the back of the operator directed bulge in upright seating position maximum, depending on the pressure exerted on the backrest pressure (contact force) continuously, so that the lumbar support is increasingly flattening. Due to the four-bar linkage here, the buckling decrease takes place practically independent of where the force or pressure is applied along the backrest. Reason is that yourself at such a pressure or force on the backrest along the two backrest portions of the upper backrest of the backrest support quasi stretches and thus the upper, relatively long backrest area is pulled vertically upwards at the upper back end. In other words: As a result of a force applied to the backrest pivoted - forced on the four-bar linkage - the comparatively short upper backrest of the backrest support to the third joint of the four-bar linkage with the result that the lumbar support - and thus the first joint located there - also after moved towards the back of the backrest. To this end, the lower, comparatively short backrest area pivots forwards about the (lower) second joint via the four-bar chain.
advantageous embodiment is the manner of a four-bar chain
effective articulation at a suitable location spring assisted.
A spring element suitable for this purpose can be attached to the joints of the articulated connection
or also in the area of the lumbar support of the two-piece
Leaning be provided. The spring force of the spring element acts
in the direction of the lordosis of the operator, with an inclination
the backrest overcome this spring force
and thus the backrest automatically becomes an increasing
Counterforce against the back of the operator exercises.
In contrast, when the operator is sitting vertically, no
or little pressure on the backrest, especially
in the lordosis area, exercised.
corresponding spring element can in the form of a leg spring, in particular
on the third joint, be provided. Alternatively, a tension spring
lean back between the two backrest areas or
Lehnenpolstern be provided. However, it is particularly advantageous
a leaf spring in the area of the lumbar support on the
Back of the operator facing side (back of the backrest)
the backrest cushion, since at this point in a particularly simple manner
and way the spring element or the leaf spring completely
and thus invisibly padded.
a further advantageous embodiment is at the (lower)
Support arm of the backrest support a headrest
appropriate. This includes a support or support frame,
in particular with two support legs, which expediently
enclose an obtuse angle with each other. At the top)
Freeing of the support frame is then a headrest main, in particular
a headrest cushion, attached.
Angled form of the support frame is preferably such
chosen that the headrest or the Kopfstützenhaupt
in a backrest position with a maximum arched
Lumbar support in vertical direction with the upper backrest area
Aligns and in a Lehne leaning position the upper backrest area
leaning forward leaning.
by virtue of
the rigid connection of this support frame with the (lower) support arm
The backrest also stays with the backrest tilted
or the two backrest areas, the relative position of the headrest
or the headrest padding opposite the (lower)
Stabilizer always the same. In contrast, be moved
the upper, on the lower backrest handlebar articulated support arm
towards the support frame with the headrest too.
In the starting position in upright seating position thus forms the
Backrest contour including the headrest the S-shape of the spine
an inclination of the back of the operator to the rear
Thus, the head is always supported in one position,
in which a view forward is still possible. Consequently
remains the position of the headrest and the corresponding
Support frame relative to the lower support arm of the backrest carrier always
same while pressing the back areas
or the backrest cushion in the direction of the backrest support
when tilting the backrest, the distance of the upper backrest area
to the headrest becomes increasingly larger
with the result that the shoulder area of the operator in the
Comparison to the head tends to lean backwards.
the two under training of the flexible lumbar support
interconnected backrest areas or cushion advantageously
deformation-resistant and thus rigid, move under load
or force the backrest, in particular
even with a tilt of the backrest in an alternative
Embodiment with a synchronous mechanism between the
Backrest and the seat of a chair, though
the two backrest areas relative to each other, but stay for yourself
undeformed. This rigid design of the two backrest areas guaranteed
also the reliable functional principle of the four-link chain, at
the four individual articulated links
To ensure this functional principle are rigid.
This embodiment thus causes that when leaning back
an operator against the backrest and also in their
additional inclination in the embodiment with
a synchronous mechanism spanned by the four-bar chain
Surface with increasing contact pressure against the backrest area
gets smaller and smaller.
The advantages achieved by the invention are in particular that due to a flexible, articulated design of the intermediate region between two superimposed back regions of a backrest and the out staltung the attachment or suspension of these backrest areas on a two-part, articulated backrest support in a particularly simple and reliable manner in an upright seating position sufficient support in the lumbar region of an operator is guaranteed. At the same time, this backrest construction provides a decreasing lumbar support in the operation of a four-bar chain with increasing inclination to a reclined seating position of the operator. This effectiveness and this operating principle corresponds to the natural behavior and comfort desire of an operator, while in the upright seating position desires support from the backrest in the lumbar region, such support in a reclined sitting position - in extreme cases in a lying position - but not required or wishes. This comfort behavior or comfort desire is due to the fact that in the upright sitting position, a vertical load on the spine, while such a burden decreases with increasing inclination of the spine in the horizontal position. So it is more comfortable with increasing inclination in the horizontal position, although the support in the lumbar region decreases accordingly.
Comfort desire is in a simple way the inventive
Backrest fair by the flexible lumbar support
in the upright seating position sufficient support
ensured in the lumbar region of an operator, with
increasing inclination in a reclined sitting position
but automatically a decreasing lumbar support
In addition, the concatenation of the hinged together provides
Elements of the backrest, namely the two backrest areas
and the two handlebars of the backrest support against a
simple flexible trained Lordosenstützbereich the
Advantage that, regardless of where on the
Backrest applied a corresponding pressure
is going to join the elements of the four-link chain together
always move the connected backrest parts to the same position.
Be embodiments of the invention with reference to a
Drawing explained in more detail. Show:
1 schematically in a side view the backrest-seat area of a chair with a flexible lumbar support having backrest with graphically highlighted four-bar chain in the starting position,
2 in a representation according to 1 the backrest in a force- or pressurized position with a flattened lumbar support,
3 the backrest according to 1 with headrest,
4 the backrest according to 3 in a position of the backrest according to 2 .
5 the design of the backrest according to 3 in conjunction with a synchronous mechanism between the seat and the backrest in starting position, and
6 the embodiment according to 5 with synchronously inclined backrest and seat.
corresponding parts are in all figures with the same reference numerals
The chair designed as an office chair 1 according to the 1 to 6 includes one with a in the 5 and 6 indicated stand connected backrest support 2 on which a two-part backrest 3 with an upper backrest area 3a and a lower backrest area 3b is held in an articulated manner. The backrest carrier 2 includes a lower support arm 20 and an articulated upper backrest handlebar 21 , The opposite the comparatively long, in the z-direction approximately vertically extending L-leg 20a Angled, in the z-direction horizontally extending comparatively short L-leg 20b carries a seat 4 ,
The upper backrest area 3a hereinafter referred to as backrest cushion backrest 3 is with the comparatively short lower backrest area 3b with the formation of a lumbar support 5 connected such that upon application of a contact force F in the direction of 2 Arrow oriented in the x-direction bulge 6 the lumbar support of the in 1 shown maximum degree of curvature in the in 2 Flattening degree is flattened.
This flexible connection between the comparatively long, upper backrest area 3a and the comparatively short, lower backrest area 3b is produced in the embodiment by a recessed back recess or recess 7 within the otherwise dimensionally stable or deformation-resistant - and thus rigid - backrest cushion 3 , Essential here is that both the upper backrest area 3a as well as the lower backrest area 3b correspondingly rigid or rigid, while the intermediate area in which the lumbar support 5 is flexible and in particular articulated. This flexibility or deformability in turn is such that in this area of the lumbar support 5 between the otherwise rigid upper backrest area and the likewise rigid lower backrest area 3b almost a (first) joint 8a one in the manner of a Vierge link chain effective articulation 8th is formed.
Like the first joint 8a there is also a second joint 8b on the back of the backrest and there in the (-) x-direction and in the z-direction below the first joint 8a , The other two joints 8c and 8d the four-jointed chain 8th are lean back on both sides of the upper backrest handlebar 21 , Specifically, this is the articulated connection between the support arm 20 and the backrest handlebar 21 forming third joint 8c in the z-direction above the first joint 8a and in (-) x-direction to the second joint 8b added.
The fourth joint 8d forms a hinged connection between the upper backrest handlebars 21 of the back support 20 and the top of the upper backrest area 3a , This fourth joint 8d is in the z-direction above the third joint 8c and in the z direction between the second joint 8b and the third joint 8c positioned. The formation of the four-jointed chain 8th associated rigid chain links are through the virtual connecting lines between the four joints 8a to 8d illustrated. The realization of these rigid joints is through the rigid handlebars 20 . 21 of the back support 20 on the one hand and through the rigid backrest areas 3a and 3b guaranteed on the other hand.
As from the representations of 1 and 2 can be seen causes a force exerted by the back of an operator pressing force F in the direction of arrow ((-) x-direction) pivoting of the upper backrest handlebar 21 around the third joint 8c with the result that the upper backrest area 3a is pulled in a z-direction vertically upwards. At the same time there is a pivoting of the lower backrest area 3b around the second joint 8b turn in (-) x-direction with the result that the first joint 8a also in (-) x direction on the in the representations according to the 1 to 4 fixed lower support arm 20 too moved. As a result, the degree of bulging of the bulge increases 6 the lumbar support 5 from the maximum bulge 6 according to 1 in the minimum bulge 6 according to 2 from. Here is the by the four-jointed chain 8th spanned surface increasingly smaller, as by comparing the representations of 1 and 2 is apparent.
The for a reversible change in the bulge 6 the lumbar support 5 required restoring force is generated by a spring element, which in principle at different locations or positions of the four-bar chain 8th can be arranged. So shows 3 alternative positions and embodiments of the spring element in the form of a leaf spring 9 , a tension spring 10 and / or a thigh spring 11 , When using the leaf spring 9 this is expediently in the area of the lumbar support 5 and there in the area of the first joint 8a the four-jointed chain 8th intended. A thigh spring 11 is suitably used in the region of the third joint 8c , Additionally or alternatively, when using the tension spring 10 this lean back between the two backrest areas 3a and 3b in the recess running transversely to the xz plane 7 provided and there on the one hand with the upper backrest area 3a and on the other hand with the lower backrest area 3b connected.
The otherwise with the embodiments according to the 1 and 2 same embodiment according to the 3 and 4 also has a headrest 12 on. This consists essentially of a turn approximately L-shaped angled support or support frame 13 and a pillow-like headrest, for example 14 , The headrest 12 is above the headrest head 14 opposite L-leg 13a of the supporting frame 13 at the lower support arm 20 of the back support 2 held. The one between this L-thigh 13a and the headrest head 14 wearing L-thighs 13b of the supporting frame 13 Ingested, in particular obtuse angle is dimensioned such that the actual headrest, ie the headrest main 14 in a backrest position with maximum arched lumbar support 5 in vertical or z-direction with the upper backrest area 3a Aligns like this 3 is apparent. In contrast, dominates the headrest head 14 in the in 4 Lehnenneigeposition shown the upper backrest area 3a in X direction.
The 5 and 6 show an embodiment of the functioning of the four-bar chain 8th realized backrest of the chair 1 with a synchronous mechanism 15 between the two backrest areas 3a . 3b and the seat 4 , The synchronous mechanism 15 essentially comprises two seat arms 16 . 17 , on the only schematically indicated seat support 18 are articulated. This is the front seat handlebar 16 over joints 16a and 16b with the seat 4 on the one hand or with the seat carrier 18 on the other hand articulated. Analog is the rear seat handlebar 17 over joints 17a and 17b with the seat 4 on the one hand or the seat carrier 19 on the other hand articulated.
As in 6 illustrates, causes the synchronous mechanism 15 a synchronous inclination movement of both the backrest and the seat 4 back and down. The relationships relative to the backrest itself with respect to the relative movement between the two backrest areas 3a and 3b as well as the two-part backrest carrier 2 corresponds to the movement behavior of the back Reject according to the 1 to 4 with a continuous decrease in the degree of curvature of the bulge 6 the lumbar support 5 with increasing contact pressure F or pressurization with the difference that at the same time also the backrest support 2 tilts backwards and downwards.
- Office / chair
- backrest support
- Back / back pad
- lumbar support
- Recess / -nehmung
- Four-bar chain / articulation
- leaf spring
- Leg spring
- Support / support stand
- Headrests main / -polster
- synchronous mechanism
- seat link
- Joint / link
- seat link
- Joint / link
- seat support
- support links
- backrest link
- contact force
QUOTES INCLUDE IN THE DESCRIPTION
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Cited patent literature