U.S. patent application number 13/813360 was filed with the patent office on 2013-05-23 for seat having a backrest which can be adjusted to form a precurved deformation.
This patent application is currently assigned to VITRA PATENTE AG. The applicant listed for this patent is Harald Gerwig. Invention is credited to Harald Gerwig.
Application Number | 20130127219 13/813360 |
Document ID | / |
Family ID | 44630465 |
Filed Date | 2013-05-23 |
United States Patent
Application |
20130127219 |
Kind Code |
A1 |
Gerwig; Harald |
May 23, 2013 |
Seat Having A Backrest Which Can Be Adjusted To Form A Precurved
Deformation
Abstract
The backrest which is designed for a seat can be adjusted to
form a precurved deformation. The backrest has a rest support (40)
having a link chain (41) comprising a large number of links
(410,411) which are interconnected such that they can move in
relation to each other. A flexible actuating element (47) with a
fixed length extends from an upper fixing point (415), which is
provided on one of the links (410,411) in the upper region of the
rest support (40), along the rest support (40) to a lower fixing
point. Each link (410,411) has a driver (412) which engages in the
link (411) arranged beneath it. The flexible actuating element (47)
is embedded in a guide (46) which is provided on the rest support
(40) and which extends from close to the upper fixing point (415)
to an intermediate space which is situated in front of the lower
fixing point. Means (43,45) for displacing the actuating element
(47) in the guide (46) and precurving the upper fixing point (415)
with an associated link (410,411) are provided for the purpose of
adjusting the backrest. The driver (412) of the link (410,411)
which is associated with the upper fixing point (415) and engages
in the next link (411) which is arranged beneath it is intended to
move this next link (411) to the precurved position. The further
drivers (412) within the link chain (41) serve in each case to move
the coupled link (411) to the precurved position.
Inventors: |
Gerwig; Harald; (Kandern,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Gerwig; Harald |
Kandern |
|
DE |
|
|
Assignee: |
VITRA PATENTE AG
Muttenz
CH
|
Family ID: |
44630465 |
Appl. No.: |
13/813360 |
Filed: |
July 30, 2011 |
PCT Filed: |
July 30, 2011 |
PCT NO: |
PCT/CH11/00175 |
371 Date: |
January 30, 2013 |
Current U.S.
Class: |
297/284.3 |
Current CPC
Class: |
A47C 7/46 20130101; A47C
7/462 20130101; A47C 7/44 20130101; A47C 1/03261 20130101; A47C
1/03277 20130101; A47C 3/30 20130101; A47C 1/03255 20130101; A47C
1/03294 20130101 |
Class at
Publication: |
297/284.3 |
International
Class: |
A47C 7/46 20060101
A47C007/46; A47C 7/44 20060101 A47C007/44; A47C 1/032 20060101
A47C001/032; A47C 3/30 20060101 A47C003/30 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 31, 2010 |
CH |
01252/10 |
Claims
1. A seat having a backrest (4), wherein: a) the backrest (4) is
able to be adjusted into a precurved deformation; and b) the
backrest (4) has a backrest support (40) with a link chain (41)
consisting of a plurality of movably interconnected links
(410,411), characterized in that c) a flexible actuating element
(47) of fixed length extends from an upper fixed point (415) which
is provided on one of the links (410,411) in the upper region of
the backrest support (40), along the backrest support (40) to a
lower fixed point (458); d) each link (410,411) has a drive element
(412) which engages in the link (411) arranged thereunder; e) the
flexible actuating element (47) is embedded in a guide (46)
provided on the backrest support (40), said guide extending from
the vicinity of the upper fixed point (415) to an intermediate
space (460) mounted in front of the lower fixed point (458); and f)
for adjusting the backrest (4): fa) means (43,45;43,45') are
provided for displacing the actuating element (47) in the guide
(46) and precurving the upper fixed point (415) with the associated
link (410,411); fb) the drive element (412) of the link (410,411)
associated with the upper fixed point (415), which engages in the
next link (411) arranged thereunder, is intended for moving said
next link (411) into the precurved position; and fc) the further
drive elements (412) inside the link chain (41) in each case serve
for moving the coupled link (411) into the precurved position.
2. The seat as claimed in claim 1, characterized in that the
inclination of the backrest (4) is able to be adjusted, wherein: a)
by the load effect, the backrest (4) adopts a successive precurved
deformation counter to the load effect, from a zero position
(R.sub.0), which in principle is vertical, to a maximum rearwardly
facing inclined position (R.sub.max); b) the backrest (4) has a
restoring spring for adjusting the backrest (4) into the zero
position (R.sub.0) in the absence of the load effect; c) a freely
floating longitudinal portion (a) of the actuating element (47)
extends through the intermediate space (460); and d) when adjusting
the backrest (4) toward the inclined position (R.sub.max) the means
(43,45;43,45') are provided for the longitudinal alteration of the
longitudinal portion (a) with the equivalent displacement of the
actuating element (47) in the guide (46) and precurving of the
upper fixed point (415) with the associated link (410,411).
3. The seat as claimed in one of claims 1 and 2, characterized in
that a) when adjusting the backrest (4) toward the inclined
position (R.sub.max), the means (43,45;43,45') for longitudinal
alteration of the longitudinal portion (a) with equivalent
displacement of the actuating element (47) in the guide (46)
generate a shortening of the longitudinal portion (a) with
equivalent insertion of the actuating element (47) into the guide
(46) and precurving of the upper fixed point (415) with the
associated link (410,411); and b) the actuating element (47) takes
the form of a leaf spring, a resilient rod or a Bowden cable or a
cord.
4. The seat as claimed in one of claims 1 to 3, characterized in
that the means (43,45;43,45') comprise: a) a backrest connector
(43) which, on the one hand, is connected to the link chain (41) as
a component of the backrest support (40) and, on the other hand, is
articulated on a first rotational axis (D1) present on the
mechanism (2); and b) an actuating arrangement (45,45') which has
the lower fixed point (458) and is connected to the backrest
connector (43).
5. The seat as claimed in one of claims 1 to 4, characterized in
that the actuating arrangement (45,45'): a) is connected to the
backrest connector (43) on a connection axis (D5); b) has means
(455,457,459) for adjusting the ratio of the precurved deformation
of the link chain (41) effected by the maximum inclined position
(R.sub.max); and c) has means (459,6) for preadjusting a precurved
deformation of the link chain (41) in the zero position
(R.sub.0).
6. The seat as claimed in at least one of claims 1 to 5,
characterized in that the actuating arrangement (45) consists of:
a) a second axle rod (456) extending in the connection axis (D5),
which rests in bearings (430) on the backrest connector (43); b)
two bearing elements (453) which are guided on the connection axis
(D5); c) a base (450) positioned between the two bearing elements
(453), said base being connected to a fixed seating component
(1,11,12,20) and having a first axle rod (452), through which a
base axis (D4) extends and which is guided on both sides in each
case in a first slot (454) in the two bearing elements (453); and
d) a receiver unit (459), on which the lower fixed point (458) is
located and which has a third axle rod (457), through which a
connection axis (D6) extends and which is articulated on both sides
on the two bearing elements (453).
7. The seat as claimed in claim 6, characterized in that for
adjusting the position of the lower fixed point (458): a) each of
the two bearing elements (453) in each case has a second slot (455)
in which the positioning of the third axle rod (457) may be
adjusted; and/or b) the receiver unit (459) is adjustable per se,
for example by lengthening and/or shortening in relation to the
third axle rod (457).
8. The seat as claimed in at least one of claims 1 to 5,
characterized in that the actuating arrangement (45') consists of:
a) a receiver unit (459), wherein: aa) the lower fixed point (458)
is located on the receiver unit (459); ab) the receiver unit (459)
has a slot (51) in which an axle pin (50) extending on the
connection axis (D5) is guided in a manner which is fixed in terms
of rotation and displaceable; and ac) a projection (52) extends
from the receiver unit (459); and b) an adjusting unit (6),
wherein: ba) the adjusting unit (6) is fastened to a seat support
(21) associated with the seat, and is preferably articulated on a
rear axis (D7) arranged on the seat support (21); bb) the adjusting
unit (6) has an impact element (61), the position thereof being
able to be varied by an actuating member (62); and bc) the impact
element (61) strikes the projection (52) in order to position the
receiver unit (459) guided on the axle pin (50), according to the
adjustment on the adjusting unit (6); and c) the projection may
have a wedge surface which bears against the impact element (61)
and is moved downward on the impact element (61) when adjusting the
backrest (4) toward the inclined position (R.sub.max).
9. The seat as claimed in one of claims 1 to 8, characterized in
that a) the link chain (41) is terminated at the very top by a top
link (410), in which the upper fixed point (415) is provided and to
which a first chain link (411) is adjoined, followed by further
chain links (411); b) a bridging link (42) adjoins the final bottom
chain link (411), which is rigidly connected to the backrest
connector (43) or is configured integrally with the backrest
connector (43); and c) the link chain (41) of the backrest support
(40) may be formed as far as the shoulder region of the user or,
lengthened in height, beyond a top part (h).
10. The seat as claimed in one of claims 1 to 9, characterized in
that a) the movable chain links between the links (410,411) of the
link chain (41) and preferably also between the final bottom chain
link (411) and the bridging link (42) are formed by hinges (417) in
the form of elements positively connected together or film hinges;
b) the link chain (41) is provided on the side remote from the seat
part (3) with rear stops (414) which, remote from the seat part
(3), block the link chain (41) and bridging link (42) from bending
to the rear; and c) the link chain (41) may be provided on the side
facing the seat part (3) with front stops (413), which block a
precurved deformation counter to the load effect, facing the seat
part (3), beyond a maximum defined mass.
11. The seat as claimed in one of claims 1 to 10, characterized in
that the mechanism (2) positioned on a lower frame (1): a) when
adjusting the backrest (4) between the zero position (R.sub.0) and
the inclined position (R.sub.max), serves for the synchronous
movement of the seat part (3) between a zero inclination (S.sub.0)
and a maximum inclination (S.sub.max); b) comprises a base part
(20), in principle fixedly positioned on the lower frame (1),
through which the first rotational axis (D1), which is fixed in
principle, extends; c) comprises a seat support (21) supporting the
seat part (3) through which a second rotational axis (D2) extends,
to which connectors (22) are articulated, on the one hand, which
are articulated, on the other hand, to the first rotational axis
(D1); and d) has a third rotational axis (D3) extending through the
base part (20), to which the seat support (21) is articulated.
12. The seat as claimed in one of claims 1 to 11, characterized in
that a) the backrest connector (43) is fastened to the connectors
(22); b) the backrest connector (43) is of two-arm configuration
and both arms have in each case a molded part at the ends facing
the connectors (22), said molded part (44) being intended for
fastening to the respectively associated connector (22); c) at
least several links (410,411) of the link chain (41) and optionally
also the bridging link (42) are provided with upholstery supports
(48), which serve for supporting an upholstered part (49) present
on the backrest (4); and the upholstery supports (48): d) are
fastened by means of connecting links (480) to the respective link
(410,411,42); or e) extend integrally from the respective link
(410,411,42).
13. The seat as claimed in at least one of claims 1 to 12,
characterized in that the link chain (41): a) is an integral
plastics molded part; or b) is an integral plastics molded part
with the upholstery supports (48); or c) is an integral plastics
molded part with the upholstery supports (48) and the bridging link
(42); or d) is an integral plastics molded part with the upholstery
supports (48), the bridging link (42) and the backrest connector
(43); and e) the restoring spring for adjusting the backrest (4)
into the zero position (R.sub.0) when there is no load effect: ea)
is an additional function of the actuating element (47) and a
separate traction element may be fixed to the backrest support (40)
for reinforcing the restoring function of the actuating element
(47), wherein the traction element is fixed between the top link
(410) and the bridging link (42), preferably on the rear side of
the backrest support (40) remote from the user; or eb) is formed by
the hinges (417) between the links (411) and/or by the additional
function of the actuating element (47) and/or the separate traction
element.
14. The seat as claimed in at least one of claims 1 to 13,
characterized in that a) on the backrest support (40) within the
link chain (41): aa) different areas of curvature are formed with a
variable precurved deformation with, in principle, variable radii
of curvature; and/or ab) different areas of rigidity are formed
with variable deformation resistance; and ac) the various areas of
curvature with the different areas of rigidity may be configured to
be superimposed on one another; and/or b) on the backrest support
(40) inside the link chain (41): ba) in the upper region thereof in
relation to the lower region a greater precurved deformation is
provided in order to provide to the user leaning into the seat,
upwards from the shoulder, with a support oriented further toward
the user, which may be achieved by different dimensioning and/or
variable use of material inside the link chain (41); and bb) the
lumbar region in relation to the remaining link chain (41) is
formed with a greater deformation resistance, in order to support
the user more firmly thereby in said body region.
15. The seat as claimed in at least one of claims 1 to 14,
characterized in that a) a spring, preferably a gas spring (12), is
arranged between the lower frame (1) and the mechanism (2) for
adjusting the seat height; b) the seat is configured as a swivel
chair; c) the base (450) of the adapter arrangement (45) is
fastened to the base part (20) of the mechanism (2) or to an
extending piston rod of the gas spring (12); d) the backrest
support (40) is provided on the side facing the user with an
upholstered part (49), which has a lumbar region and at the top may
have a top part (h); wherein e) a height-adjustable support element
is provided in the lumbar region of the upholstered part (49), and
the top part (h) is vertically displaceable.
Description
FIELD OF APPLICATION OF THE INVENTION
[0001] The present invention relates to a seat comprising a
backrest which may be adjusted into a precurved deformation. The
backrest has a backrest support with a link chain consisting of a
plurality of movably interconnected links. The invention relates,
in particular, to vehicle seats and chairs, including office swivel
chairs, which may be adjusted in the seat height thereof, wherein a
synchronous adjustment of the seat inclination follows the
inclination of the backrest. In a typical design, a spring,
preferably a gas spring, for adjusting the seat height is arranged
between the chair lower frame and the mechanism resting thereon. In
one particular embodiment, as a result of the load effect the
backrest fastened to the mechanism adopts a successively precurved
deformation counter to the load effect from a zero position which
in principle is vertical to a maximum rearwardly inclined
position.
PRIOR ART
[0002] A seat shell is disclosed in DE 36 04 534 A1, transversely
extending resilient areas being provided in the back part thereof
for flexibility when a user leans back into the seat. The resilient
areas are formed by transverse ribs bridged relative to one another
by film hinges. Stop elements are located between the transverse
ribs, said stop elements colliding when bent back to the maximum
permitted extent.
[0003] U.S. Pat. No. 5,328,245 discloses a backrest having a
plurality of elements which are, in principle, horizontally
displaceable relative to one another and which are adapted in
profile to the contour of a user leaning against said backrest. All
the elements may be locked in position after adapting the profile
to the individual user. The object of adapting the backrest to the
back profile of a user by a plurality of chambers extending
transversely over the flexible plastics back and superimposed over
one another is achieved in DE 10 2004 032 765 B4. The chambers may
be pumped up with air to a variable extent so that they are
deformed to different degrees of flexibility in order to be adapted
to the back of the individual user.
[0004] The subject-matter of DE 42 16 159 A1 is a chair, the
backrest thereof when inclined to the rear synchronously driving
the seat which is lowered in the rear region. The backrest is
subdivided at least twice, namely into an upper and a lower part,
wherein the parts are connected together in an articulated manner
via horizontal axes. To the rear of the backrest, an upwardly
protruding supporting arm is present, from which in the pelvic
region an articulated transverse lever extends to the backrest and
is also articulated at that point. When inclined to the rear, the
backrest is lowered in its entirety, and at the same time the seat
is slightly lowered in the front region and to a greater extent in
the rear region. Due to the displacement between the backrest and
the supporting arm, the transverse lever reaches the horizontal
position and thus pushes the lower part of the backrest against the
user.
[0005] The chair according to DE 195 02 485 C2 has a base
positioned on a lower frame, said base extending from below the
seat as far as half way up the backrest. The base and seat are
connected together by a first lever articulated on both sides on
the front region thereof. In the upwardly curved part of the base
is located a stirrup which is displaceable in an arcuate groove,
which is connected in an articulated manner to the rear region of
the seat via a second lever articulated to the stirrup. A third
lever extends to the backrest from the upper stirrup end with an
articulation on both sides. In the writing position, the user
exerts a load on the front seat region, which is thus lowered and
pulls the stirrup upwards via the second lever and, as a result,
also moves the backrest upward and toward the user. If the user
displaces his/her weight onto the rear seat region, the backrest is
synchronously moved downward when the seat is lowered.
[0006] The chair according to WO 2007/038 879 A1 has a lower frame
positioned on the floor, a mechanism positioned on the lower frame,
a seat positioned on the mechanism and a backrest fastened to the
mechanism. The backrest has a backrest frame which bears a
resiliently deformable backrest part having a back plate. The back
plate has a back part to which a headrest attachment is connected.
The backrest is able to be pivoted about a first rotational axis
from a zero position which is upright in principle, as far as an
inclined position facing to the rear. The movements of the seat and
backrest are synchronized with one another. With resilient
deformation of the back part into a free intermediate space
relative to the backrest frame, by the action of a force in the
direction of the inclined position with, in principle, a concave
tendency relative to the back of the user, means are provided for
an opposing lifting of the shoulder region as a transition area of
the back part relative to the headrest attachment and of the
headrest attachment. Said means are substantially in each case a
support articulated on both sides between the backrest frame and
the back plate.
[0007] U.S. Pat. No. 6,986,549 B2 finally discloses a backrest
support which initially consists of two curved S-shaped flexible
tracks coming together at the upper ends in a V-shape. The tracks
are subdivided into a plurality of portions connected together by
film hinges. An opening is provided in the region of each film
hinge, and between the opposing openings in each case a rigid rib
is fastened which is pivotable in the vertical plane, said rib
holding the two tracks spaced apart from one another. Below the
seat, a plurality of traction cables are tensioned and which in
each case are fastened by the front track through an opening
transversely to the rear track on the next highest rib. When
inclining the backrest support to the rear, due to a cable
extension which is not available, the connection of the traction
cable together with the rib and adjacent portions of the tracks are
precurved in the direction of the user.
OBJECT OF THE INVENTION
[0008] Based on the hitherto known prior art, the object of the
invention is to propose a seat with perfect ergonomic function. In
particular, when the backrest is located in the inclined position
moved to the rear, the support of the shoulder region and head of
the user is improved.
[0009] It should be taken into consideration here that the seat may
also be provided with a so-called synchronous mechanism, in order
to produce an adequate adjustment of the inclination of the seat
with an adjustment of the inclination of the backrest, and fulfill
the functions of a height-adjustable office swivel chair.
OVERVIEW OF THE INVENTION
[0010] The backrest designed for a seat is able to be adjusted into
a precurved deformation. The backrest has a backrest support with a
link chain consisting of a plurality of movably interconnected
links. A flexible actuating element of fixed length extends from an
upper fixed point which is provided on one of the links in the
upper region of the backrest support, along the backrest support to
a lower fixed point. Each link has a drive element which engages in
the link arranged thereunder. The flexible actuating element is
embedded in a guide provided on the backrest support, said guide
extending from the vicinity of the upper fixed point to an
intermediate space mounted in front of the lower fixed point. For
adjusting the backrest, means are provided for displacing the
actuating element in the guide and precurving the upper fixed point
with the associated link. The drive element of the link associated
with the upper fixed point, which engages in the next link arranged
thereunder, is intended for moving said next link into the
precurved position. The further drive elements inside the link
chain in each case serve for moving the coupled link into the
precurved position.
[0011] The following features relate to specific embodiments of the
invention:
[0012] The inclination of the backrest is able to be adjusted,
wherein: [0013] a) by the load effect, the backrest adopts a
successive precurved deformation counter to the load effect, from a
zero position, which in principle is vertical, to a maximum
rearwardly facing inclined position; [0014] b) the backrest has a
restoring spring for adjusting the backrest into the zero position
in the absence of the load effect; [0015] c) a freely floating
longitudinal portion of the actuating element extends through the
intermediate space; and [0016] d) when adjusting the backrest
toward the inclined position the means are provided for the
longitudinal alteration of the longitudinal portion with the
equivalent displacement of the actuating element in the guide and
precurving of the upper fixed point with the associated link.
[0017] When adjusting the backrest toward the inclined position,
the means for longitudinal alteration of the longitudinal portion
with equivalent displacement of the actuating element in the guide
generate a shortening of the longitudinal portion with equivalent
insertion of the actuating element into the guide and precurving of
the upper fixed point with the associated link. The actuating
element takes the form of a leaf spring, a resilient rod or a
Bowden cable or a cord.
[0018] The means comprise: [0019] a) a backrest connector which, on
the one hand, is connected to the link chain as a component of the
backrest support and, on the other hand, is articulated on a first
rotational axis present on the mechanism; and [0020] b) an
actuating arrangement which has the lower fixed point and is
connected to the backrest connector.
[0021] The actuating arrangement: [0022] a) is connected to the
backrest connector on a connection axis; [0023] b) has means for
adjusting the ratio of the precurved deformation of the link chain
effected by the maximum inclined position; and [0024] c) has means
for preadjusting a precurved deformation of the link chain in the
zero position.
[0025] The actuating arrangement consists of: [0026] a) a second
axle rod extending in the connection axis, which rests in bearings
on the backrest connector; [0027] b) two bearing elements which are
guided on the connection axis; [0028] c) a base positioned between
the two bearing elements, said base being connected to a fixed
seating component and having a first axle rod, through which a base
axis extends and which is guided on both sides in each case in a
first slot in the two bearing elements; and [0029] d) a receiver
unit, on which the lower fixed point is located and which has a
third axle rod, through which a connection axis extends and which
is articulated on both sides on the two bearing elements.
[0030] For adjusting the position of the lower fixed point: [0031]
a) each of the two bearing elements in each case has a second slot
in which the positioning of the third axle rod may be adjusted;
and/or [0032] b) the receiver unit is adjustable per se, for
example by lengthening and/or shortening in relation to the third
axle rod.
[0033] Alternatively, the actuating arrangement in a second variant
consists of: [0034] a) a receiver unit, wherein: [0035] aa) the
lower fixed point is located on the receiver unit; [0036] ab) the
receiver unit has a slot in which an axle pin extending on the
connection axis is guided in a manner which is fixed in terms of
rotation and displaceable; and [0037] ac) a projection extends from
the receiver unit; and [0038] b) an adjusting unit, wherein: [0039]
ba) the adjusting unit is fastened to a seat support associated
with the seat, and is preferably articulated on a rear axis
arranged on the seat support; [0040] bb) the adjusting unit has an
impact element, the position thereof being able to be varied by an
actuating member; and [0041] bc) the impact element strikes the
projection in order to position the receiver unit guided on the
axle pin, according to the adjustment on the adjusting unit.
[0042] The projection bears against the impact element with a wedge
surface and is moved downward on the impact element, when adjusting
the backrest toward the inclined position.
[0043] The link chain is terminated at the very top by a top link,
in which the upper fixed point is provided and to which a first
chain link is adjoined, followed by further chain links. A bridging
link adjoins the final bottom chain link, which is rigidly
connected to the backrest connector or is configured integrally
with the backrest connector. The link chain of the backrest support
may be formed as far as the shoulder region of the user or,
lengthened in height, beyond a top part.
[0044] The movable chain links between the links of the link chain
and preferably also between the final bottom chain link and the
bridging link are formed by hinges in the form of elements
positively connected together or film hinges. The link chain is
provided on the side remote from the seat part with rear stops
which, remote from the seat part, block the link chain and bridging
link from bending to the rear. The link chain may be provided on
the side facing the seat part with front stops, which block a
precurved deformation counter to the load effect, facing the seat
part, beyond a maximum defined mass.
[0045] The mechanism positioned on a lower frame: [0046] a) when
adjusting the backrest between the zero position and the inclined
position, serves for the synchronous movement of the seat part
between a zero inclination and a maximum inclination; [0047] b)
comprises a base part, in principle fixedly positioned on the lower
frame, through which the first rotational axis, which is fixed in
principle, extends; [0048] c) comprises a seat support supporting
the seat part through which a second rotational axis extends, to
which connectors are articulated, on the one hand, which are
articulated, on the other hand, to the first rotational axis; and
[0049] d) has a third rotational axis extending through the base
part, to which the seat support is articulated.
[0050] The backrest connector is fastened to the connectors. The
backrest connector is of two-arm configuration and both arms have
in each case a molded part at the ends facing the connectors, said
molded part being intended for fastening to the respectively
associated connector. At least several links of the link chain and
optionally also the bridging link are provided with upholstery
supports, which serve for supporting an upholstered part present on
the backrest. The upholstery supports are fastened by means of
connecting links to the respective link or extend integrally from
the respective link.
[0051] The link chain: [0052] a) is an integral plastics molded
part; or [0053] b) is an integral plastics molded part with the
upholstery supports; or [0054] c) is an integral plastics molded
part with the upholstery supports and the bridging link; or [0055]
d) is an integral plastics molded part with the upholstery supports
and the bridging link and the backrest connector. The restoring
spring--for adjusting the backrest into the zero position when
there is no load effect--is an additional function of the actuating
element and a separate traction element may be fixed to the
backrest support for reinforcing the restoring function of the
actuating element. In this case, the traction element is fixed
between the top link and the bridging link, preferably on the rear
side of the backrest support remote from the user. Alternatively,
the restoring spring is formed by the hinges between the links
and/or by the additional function of the actuating element and/or
the separate traction element.
[0056] On the backrest support within the link chain: [0057] a)
various areas of curvature are formed with a variable precurved
deformation with, in principle, variable radii of curvature; and/or
[0058] b) different areas of rigidity are formed with variable
deformation resistance; and [0059] c) the various areas of
curvature with the different areas of rigidity may be configured to
be superimposed on one another.
[0060] On the backrest support inside the link chain, in a
particular embodiment: [0061] a) in the upper region thereof in
relation to the lower region a greater precurved deformation is
provided in order to provide to the user leaning into the seat,
upwards from the shoulder, with a support oriented further toward
the user, which may be achieved by different dimensioning and/or
variable use of material inside the link chain; and [0062] b) the
lumbar region in relation to the remaining link chain is formed
with a greater deformation resistance, in order to support the user
more firmly thereby in said body region.
[0063] A spring, preferably a gas spring, is arranged between the
lower frame and the mechanism for adjusting the seat height. The
seat is configured as a swivel chair. The base of the adapter
arrangement is fastened to the base part of the mechanism or to an
extending piston rod of the gas spring.
[0064] The backrest support is provided on the side facing the user
with an upholstered part, which has a lumbar region and at the top
may have a top part. A height-adjustable support element is
provided in the lumbar region of the upholstered part and the top
part is vertically displaceable.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0065] In the drawings:
[0066] FIG. 1A--shows a chair according to the invention in the
form of an office swivel chair with a backrest extended by a top
part, in the upright zero position, in a perspective front
view;
[0067] FIG. 1B--shows the chair according to FIG. 1A with the
visible backrest support of the first variant in a perspective rear
view;
[0068] FIG. 1C--shows the chair according to FIG. 1A in a side
view;
[0069] FIG. 1D--shows the chair according to FIG. 1C without the
top part;
[0070] FIG. 2A--shows the chair according to FIG. 1A in the maximum
inclined position in a perspective front view;
[0071] FIG. 2B--shows the chair according to FIG. 2A in a
perspective rear view;
[0072] FIG. 2C--shows the chair according to FIG. 2A in side
view;
[0073] FIG. 2D--shows the chair according to FIG. 2C without the
top part;
[0074] FIG. 3A--shows the mechanism of FIG. 1A in a perspective
front view from above;
[0075] FIG. 3B--shows the mechanism according to FIG. 3A in a side
view;
[0076] FIG. 3C--shows the mechanism according to FIG. 3A with the
seat in position, in a perspective front view from below;
[0077] FIG. 3D--shows the construction according to FIG. 3C in a
perspective rear view from below;
[0078] FIG. 4A--shows the backrest support of FIG. 1B, without the
upholstery support in the upright zero position, in a perspective
front view;
[0079] FIG. 4B--shows the construction according to FIG. 4A in a
perspective rear view from below;
[0080] FIG. 4C--shows the construction according to FIG. 4A as a
basic sectional view;
[0081] FIG. 4D--shows the enlarged detail X1 of FIG. 4C;
[0082] FIG. 4E--shows the enlarged detail X2 of FIG. 4C;
[0083] FIG. 5A--shows the backrest support according to FIG. 4A,
completed with the upholstery supports and upholstery to form a
backrest, in the upright zero position, in a perspective rear
view;
[0084] FIG. 5B--shows the backrest according to FIG. 5A in a
perspective rear view from below;
[0085] FIG. 5C--shows the backrest according to FIG. 5A in a
perspective front view;
[0086] FIG. 5D--shows the backrest according to FIG. 5A with the
pushing element as a basic sectional view;
[0087] FIG. 6A--shows the construction according to FIG. 4A with
the pushing element, in a perspective exploded view;
[0088] FIG. 6B--shows the enlarged detail X5 of FIG. 6A;
[0089] FIG. 6C--shows the enlarged detail X6 of FIG. 6A;
[0090] FIG. 7A--shows the construction according to FIG. 4A in the
maximum inclined position in a perspective front view;
[0091] FIG. 7B--shows the construction according to FIG. 7A in a
perspective rear view from below;
[0092] FIG. 7C--shows the construction according to FIG. 7A as a
basic sectional view;
[0093] FIG. 7D--shows the enlarged detail X3 of FIG. 7C;
[0094] FIG. 7E--shows the enlarged detail X4 of FIG. 7C;
[0095] FIG. 8A--shows the base part of the mechanism positioned on
the lower frame, with the fittings, connectors, backrest connector,
actuating arrangement and raised seat support in a perspective plan
view;
[0096] FIG. 8B--shows the construction according to FIG. 8A in a
perspective view from below;
[0097] FIG. 8C--shows the construction according to FIG. 8A with
the seat support positioned on the base part, in a perspective plan
view;
[0098] FIG. 9A--shows the assembly consisting of the mechanism,
backrest connector, molded parts and actuating arrangement in a
first setting, in the zero position, as a basic view;
[0099] FIG. 9B--shows the assembly according to FIG. 9A in the
maximum inclined position;
[0100] FIG. 10A--shows the assembly according to FIG. 9A with the
actuating arrangement in a second setting, in the zero
position;
[0101] FIG. 10B--shows the assembly according to FIG. 10A in the
maximum inclined position;
[0102] FIG. 11A--shows the assembly according to FIG. 9A with the
actuating arrangement in a third setting in the zero position;
[0103] FIG. 11B--shows the assembly according to FIG. 11A in the
maximum inclined position;
[0104] FIG. 12A--shows the assembly according to FIG. 9A with the
actuating arrangement in a fourth setting in the zero position;
[0105] FIG. 12B--shows the assembly according to FIG. 12A, in the
maximum inclined position;
[0106] FIG. 13A--shows a backrest support of the second variant in
the upright zero position in a perspective rear view;
[0107] FIG. 13B--shows the link chain and bridging link of FIG. 13A
in the upright zero position in a perspective front view;
[0108] FIG. 13C--shows the construction according to FIG. 13A in
the upright zero position as a basic sectional view;
[0109] FIG. 14A--shows the construction according to FIG. 13B in
the maximum inclined position in a perspective rear view;
[0110] FIG. 14B--shows the construction according to FIG. 14A in
the maximum inclined position in a perspective front view;
[0111] FIG. 14C--shows the construction according to FIG. 14A in
the maximum inclined position as a basic sectional view;
[0112] FIG. 15A--shows the construction according to FIG. 9A with
an actuating arrangement of the second variant and the actuating
element attached thereto with a guide, in the zero position, as a
basic sectional view;
[0113] FIG. 15B--shows the construction according to FIG. 15A in a
perspective view;
[0114] FIG. 15C--shows the enlarged detail X7 of FIG. 15A;
[0115] FIG. 15D--shows the construction according to FIG. 15A in
the maximum inclined position as a basic sectional view; and
[0116] FIG. 15E--shows the enlarged detail X8 of FIG. 15D.
EXEMPLARY EMBODIMENT
[0117] With reference to the accompanying drawings, an exemplary
embodiment of the seat according to the invention is described in
detail hereinafter, with alternative designs of the backrest and
the actuating arrangement present thereon.
[0118] The following statement applies to the entire remaining
description. If reference numerals are contained in a figure for
the purpose of illustrative clarity, but not explained in the
immediately associated text of the description, reference is made
to where said reference numerals are mentioned in the previous
description of the figures. For the sake of clarity, a repeated
description of components in the following figures is generally
dispensed with, provided it may be identified clearly in terms of
illustration that the components are "recurring" components.
FIGS. 1A to 1D
[0119] The seat shown in the form of an office swivel chair
consists of the lower frame 1 positioned on the floor, the
mechanism 2 resting thereon, on which the seat part 3 is mounted,
as well as a backrest 4 which in a comfortable design has a top
part h, and is provided with an upholstered part 49. Typically, the
lower frame 1 initially has a foot 10--for example a 5-arm
star-shaped foot--which rests on floor elements 14, preferably
casters. For adjusting the level of the seat part 3 and at the same
time for the suspension, a gas spring 12 in a vertical tube 11 is
vertically inserted centrally into the foot 10, which bears the
mechanism 2. The structure of the backrest 4 consists of the
backrest support 40--in this case in a first variant--the
upholstery support 48 and the upholstered part 49 resting thereon.
The backrest support 40 comprises a link chain 41, the bridging
link 42 attached thereto at the bottom, and which is connected to
the backrest connector 43, as well as the actuating arrangement 45
in a first variant. By means of connecting links 480, plate-shaped
upholstery supports 48 are fastened to the link chain 41 and the
bridging link 42, against which the upholstered part 49 bears. The
backrest connector 43 leads to the mechanism 2. As a swivel chair,
said chair may be pivoted about a vertical rotational axis
generally by 360.degree., and in the unloaded state remains in the
zero position, which is enforced by the pretensioning of the spring
assembly in the mechanism 2, and is limited by a stop in the
direction of forward inclination.
[0120] The zero position is defined by the following positions:
[0121] the zero position S.sub.0 of the seat part 3: i.e. the
surface of the seat part 3 is at least in principle horizontal;
[0122] the zero position R.sub.0 of the backrest support 40: i.e.
the link chain 41 supporting the user and the bridging link 42 are
in principle vertical and thus complement the upright seating
position of a user.
[0123] The first rotational axis D1, which is fixed in principle,
the second rotational axis D2 which is pivotable about the first
rotational axis D1, as well as the third rotational axis D3, which
is also fixed in principle, extend through the mechanism 2.
Initially also visible are the fourth rotational axis D4 and the
fifth rotational axis D5 which extend through the actuating
arrangement 45.
FIGS. 2A to 2D
[0124] Due to the load effect produced by a user on the backrest 4,
said backrest is able to move fully into the maximum rearwardly
inclined position R.sub.max. The design of the mechanism 2 as a
synchronous mechanism follows the seat part 3 from the previous
zero position S.sub.0 into the maximum seat inclination S.sub.max.
According to the invention, here, the backrest 4 with the link
chain 41 in the backrest support 40 reaches a precurved deformation
counter to the load effect, so that the user leaning into the seat
is supported with an upright tendency, in particular in the
shoulder and head region, and the user's eyes maintain a virtually
horizontal viewing direction.
[0125] In the backrest 4, a restoring spring, not shown, is
provided, which in the absence of the load effect, effects the
adjustment of the backrest 4 with the backrest support 40 into the
zero position R.sub.0. The embodiments according to FIGS. 2A-2C are
provided with the top part h, whilst in the embodiment according to
FIG. 2D, the link chain 41 is shortened and thus does not have a
top part h.
FIGS. 3A to 3D
[0126] The mechanism 2 is disclosed in the patent publications WO
2005/120291A1 and WO 2007/038879A1, and substantially consists of
the base part 20, the seat support 21 positioned thereon and the
connectors 22. The base part 20 is fixedly positioned with its
opening 200 on the upper end of the extendable piston rod, a gas
spring 12 arranged in a vertical tube 11. The two angular
connectors 22 are articulated on the first rotational axis D1
which, at the same time, are articulated on the second rotational
axis D2 in the bearing recesses 210 in the rear region of the
pivotable seat support 21. In the front region, the base part 20
and the seat support 21 are connected together on the third
rotational axis D3. On both sides of the seat support 21 in each
case extends an armrest connecting piece 24 into which the free end
of the support arm of an armrest may be introduced. Additionally,
an adjustment connecting piece 25 may be present adjacent to one of
the armrest connecting pieces 24, in which an actuating member
rests, which when actuated permits the adjustment of the so-called
seat depth, by the upholstered plate 30 mounted on the seat support
21, which forms the underside of the seat 3, being released from a
blocked position and being displaceable in a limited manner. The
conventional height-adjustment lever 26 is present on the mechanism
2 in order to release the piston rod of the gas spring 12 from the
blocked position, and thus raise the seat part 3. The blocking
lever 27 serves for blocking the mechanism 2, so that the backrest
4 is not able to be moved from the vertical zero position into the
inclined position R.sub.max. Finally, a pretensioning lever 28 is
present, which serves to adjust a force to be applied for the
adjustment of the backrest 4, on the spring system not shown,
associated with the mechanism 2.
FIGS. 4A to 6C
[0127] This sequence of figures illustrates the structural design
of the complete backrest 4 with the entire backrest support 40,
comprising the link chain 41, bridging link 42, backrest connector
43, molded parts 44 and actuating arrangement 45 in the current
zero position R.sub.0. The link chain 41, also comprising a top
part h, starts at the very top with a top link 410, which is
connected by means of a hinge 417 to a first link 411. Further
links 411 interlinked by hinges 417, follow said first link 411,
wherein the lowest link 411 is connected via a hinge 417 to the
immobile bridging link 42. Each link 411 partially contributes to
an upper and lower hinge 417. The upper hinge 417 serves for the
connection to the link 411 arranged above the relevant link 411
and/or top link 410, and the lower hinge 417 serves for the
connection to the link 411 arranged below the relevant link 411
and/or bridging link 42. A hinge 417 in this case consists of a pin
in the top link 410 and in the links 411, as well as pin holes in
the links 411 and in the bridging link 42.
[0128] On the front face, in each case between the links
410,411,42, a front stop 413 is present which defines the maximum
possible forward inclined angular position between the links
410,411,42. In any case between the front stops 413, which belong
to the top link 410 and the subsequent links 411--namely those
links 410,411 which are moved in the inclined position R.sub.max
into the precurved deformation--in each case an open gap is
present, in order to permit the movement of the links 410,411
toward one another counter to the load effect. The connecting links
480 for fastening the upholstered support 48 are mounted on the
front stops 413. A rear stop 414 is arranged on the rear face in
each case between the links 410,411,42, which prevents the
rearwardly inclined angular position between the links 410,411,42,
and thus the rear stops 414 abut against one another without gaps.
The top link 410 and the adjacent chain-like links 411 in each case
have a drive element 412, which from a defined forwardly inclined
angular position drives the next link down 411 into a forwardly
inclined angular position.
[0129] The rear stops 414, with in each case a cover plate 416
mounted inside the link chain 41, enclose a through-hole which
together form the upper part of the guide 46 for the actuating
element 47. The guide 46 terminates in the top link 410 with an
additional cover plate 416 on the upper fixed point 415 as the
clamping point for the actuating element 47. From the lowest link
411, the guide 46 merges with the elongated bridging link 42 and
extends as far as the guide opening 462 at the lower end of the
bridging link 42. The actuating element 47 extends from the upper
fixed point 415 through the guide 46, enters a free intermediate
space 460 at the guide opening 462 and is gripped on the lower
fixed point 458 of a receiver unit 459. Inside the free
intermediate space 460 the actuating element 47 extends in a curved
path as a freely floating longitudinal portion a.
[0130] For fastening the backrest support 40 to the two connectors
22 of the mechanism 2 each of the two arms of the backrest
connector 43 on the lower end is provided with a molded part 44,
which has the first retaining contour 441 and the second retaining
contour 442, in order to dock onto the associated connector 22. The
lower part of the bridging link 41 is fitted between the two
upwardly oriented arms of the backrest connector 43.
[0131] The actuating arrangement 45 is connected to the backrest
connector 43 on the fifth rotational axis D5. To this end, in the
vicinity of the molded parts 44 on each arm of the backrest
connector 43 a bearing element 430 is present in order to receive
therein a second axle rod 456, through which the fifth rotational
axis D5 extends. The adapter arrangement 45 further consists of:
[0132] two bearing elements 453 configured as angled portions,
which are guided on the fifth rotational axis D5; [0133] a base 450
positioned between the two bearing elements 453, which is connected
to the base part 20 of the mechanism 2 or to the opening 451,
comprising the extendable piston rod of the gas spring 12, and has
a first axle rod 452, through which the fourth rotational axis D4
extends and which on both sides in one respective first slot 454,
is guided into the two bearing elements 453; and [0134] a receiver
unit 459, on which the lower fixed point 458 is located and which
has a third axle rod 457, through which a sixth rotational axis D6
extends and which is articulated on both sides to the two bearing
elements 453.
[0135] For adjusting the position of the lower fixed point 458,
each of the two bearing elements 453 has one respective second slot
455, in which the positioning of the third axle rod 457 is
adjustable. Moreover, the receiver unit 459 is adjustable per se,
for example by the lengthening and/or shortening thereof in
relation to the third axle rod 457. To this end, the front part of
the receiver unit 459--the lower fixed point 458 is located
there--may be adjusted by the rear anchor part of the receiver unit
459 connected thereto--the third axle rod 457 is inserted
therein--from a very tight joint to a selectable spacing.
[0136] In the current upright zero position R.sub.0 of the backrest
support 40 and the opposing adjustment of the receiver unit 459,
are located--starting from the fixed fourth rotational axis D4--the
fifth rotational axis D5 above D4, in relation to the backrest
support 40, and the sixth rotational axis D6 in principle
vertically above D5. The bearing elements 453 are such that the
first slot 454 is virtually horizontally aligned and the second
slot 455 is virtually vertically aligned. The actuating arrangement
45 is located in a second setting (see also FIG. 10A), i.e. the
sixth rotational axis D6 with the anchor part of the receiver unit
459 plugged thereon is located in the second slot 455 in the lowest
position and the front part of the receiver unit 459 is adjusted to
be spaced apart from the anchor part.
[0137] With the plate-shaped upholstered supports 48 fastened to
the connecting links 480 and the upholstered part 49 attached
thereto, a complete backrest 4 is produced which extends over the
lumbar and shoulder region as well as the lengthened top part
h.
FIGS. 7A to 7E
[0138] This sequence of figures illustrates the details of the
entire backrest support 40 in the maximum inclined position
R.sub.max now adopted by the load effect on the backrest 4. The
assembly of the molded parts 44, backrest connector 43 and bridging
link 42 rigidly connected together is inclined to the rear and has
entrained the entire link chain 41. By the rearward inclination of
the bearing elements 430 on the backrest connector 43, the fifth
rotational axis D5 is moved downwards and the bearing elements 453
guided into the first slots 454 on the fourth rotational axis D4
are pulled into the oblique position. Starting from the fixed
fourth rotational axis D4, the fifth rotational axis D5 is now
below D4, in relation to the backrest support 40, and the sixth
rotational axis D6 above D5. The bearing elements 453 are such that
the first slot 454 and the second slot 455 are aligned in a V-shape
relative to the floor. The actuating arrangement 45 is further
located in the second setting, thus the sixth rotational axis D6
with the anchor part of the receiver unit 459 plugged thereon is
located in the second slot 455 in the lowest position and the front
part of the receiver unit 459 is spaced apart from the anchor
part.
[0139] Thus by the guide opening 462 and the lower fixed point 458
approaching one another, the intermediate space 460 has been
narrowed and the freely floating longitudinal portion a of the
actuating element 47 is shortened. By the nature of the flexible
actuating element 47, the positioning of the guide opening 462 and
the lower fixed point 458 as well as the forced path of the
actuating element 47 in the guide 46, at least a substantial
component of the shortening of the longitudinal portion a along the
guide 46 is pushed against the upper fixed point 415. A deformation
curved to the rear between the links 410,411 is excluded by the
rear stops 414 striking one another. The rear positioning of the
upper fixed point 415 on the top link 410 when the actuating
element 47 is lifted promotes merely the forward bending thereof
counter to the load effect. The drive element 412 on the top link
410 effects a similarly forwardly oriented bending of the next link
411, which in turn pulls forward the following link 411 by means of
the associated drive element 412. Depending on the dimensioning,
the precurved deformation only continues to a few adjacent links
411 inside that located in the direction of the bridging link 42,
i.e. the links 411 located closer to the bridging link 42, in the
lumbar region of the user, are no longer able to be included in the
forwardly curved deflection. By different dimensioning inside the
link chain 41, in the upper region thereof--substantially above the
top part h--a greater precurved deformation may be achieved than
downwards in the direction of the bridging link 42 to the lumbar
region of the user. Thus the user leaning back into the seat, from
the shoulder upwards, experiences a support oriented further toward
him/her. Moreover, areas of variable stiffness may be formed inside
the link chain 41 so that, for example, the lumbar region on the
seat provides to the user leaning against the seat a greater
resistance against deformation--i.e. acts harder--and therefore
supports the user more firmly in said body region.
FIGS. 8A to 8C
[0140] This sequence of figures illustrates as a complement to
FIGS. 3A-3D the assembly consisting of the lower frame 1, the base
part 20 positioned thereon of the mechanism 2, connectors 22,
backrest connector 43, actuating arrangement 45 and the initially
still raised seat support 21 (see FIGS. 8A and 8B). The entire
backrest support 40 is fastened with its backrest connector 43 to
the connectors 22. In this case, the molded parts 44 are preferably
screwed to the connectors 22, and the first retaining contours 441
of the molded parts 44 engage behind through-holes, not denoted, on
the connectors 22 in the vicinity of the second rotational axis D2.
The base 450 of the actuating arrangement 45 is located with its
opening 451 on the extending piston rod of the gas spring 12 or
could be fastened to the base part 20. When the seat support 21 is
positioned on the base part 20 (see FIG. 8C), both are connected
together on the second rotational axis D2 and the third rotational
axis D3. Typically for a synchronous mechanism 2, the seat support
21 follows a rearward inclination of the backrest support 40 in the
direction of the maximum seat inclination S.sub.max lowered to the
rear. If the seat is to be designed neither as a swivel chair nor
able to be adjusted in height, a fastening of the base 450 to a
further fixed part of the seat, for example the lower frame 1, is
also considered.
FIGS. 9A to 12B
[0141] The following four pairs of figures show the actuating
arrangement 45 of the first variant in four different settings,
namely in each case in the zero position R.sub.0 of the backrest
support 40 with associated zero inclination S.sub.0 of the seat
support 21 and in the maximum inclined position R.sub.max thereof,
with associated maximum seat inclination S.sub.max.
[0142] In the first setting (see FIGS. 9A and 9B), the sixth
rotational axis D6 is located with the anchor part of the receiver
unit 459 plugged thereon in the second slot 455 in the lowest
position. Thus a low ratio is present of the precurved deformation
of the link chain 41 effected by the maximum inclined position
R.sub.max. When adjusting the front part of the receiver unit 459
without spacing from the anchor part, as a preadjustment in the
zero position R.sub.0 of the backrest support 40 with associated
zero inclination S.sub.0 of the seat support 21, no or only minimal
precurved deformation of the link chain 41 results. When changing
from the zero position R.sub.0/zero inclination S.sub.0 into the
maximum inclined position R.sub.max/seat inclination S.sub.max, the
link chain 41 is subjected to the smallest precurved deformation in
relation to its initial position.
[0143] In the second setting (see FIGS. 10A and 10B) the sixth
rotational axis D6 with the plugged-on anchor part of the receiver
unit 459 is located in the second slot 455, also in the lowest
position, but the front part of the receiver unit 459 is spaced
apart from the anchor part. When moving from the zero position
R.sub.0/zero inclination S.sub.0, into the maximum inclined
position R.sub.max/seat inclination S.sub.max, the ratio of the
precurved deformation of the link chain 41 effected by the maximum
inclined position R.sub.max, therefore, remains unaltered relative
to the first setting. However, a greater precurved deformation of
the link chain 41 already results as a preadjustment in the zero
position R.sub.0 of the backrest support 40 with the associated
zero inclination S.sub.0 of the seat support 21. In the maximum
inclined position R.sub.max/seat inclination S.sub.max--in
comparison with the first setting--a more extensive precurved
deformation of the link chain 41 thus results.
[0144] In the third setting (see FIGS. 11A and 11B) the sixth
rotational axis D6 with the anchor part of the receiver unit 459
plugged thereon is now located in the second slot 455 in the
highest position and the front part of the receiver unit 459 is
adjusted so as not to be spaced apart from the anchor part. Thus a
high ratio of the precurved deformation of the link chain 41
effected by the maximum inclined position R.sub.max is selected.
The preadjustment of the precurved deformation of the link chain 41
in the zero position R.sub.0 of the backrest support 40 with the
associated zero inclination S.sub.0 of the seat support 21
corresponds to the first setting. Due to the higher ratio when
reaching the maximum inclined position R.sub.max/seat inclination
S.sub.max--in comparison with the first setting--a more extensive
precurved deformation of the link chain 41 is produced.
[0145] In the fourth setting. (see FIGS. 12A and 12B) the sixth
rotational axis D6 is located in the second slot 455 in the highest
position and the front part of the receiver unit 459 is
additionally adjusted so as to be spaced apart from the anchor
part. Thus a high ratio according to the third setting is selected
and at the same time a preadjustment according to the second
setting so that in the maximum inclined position R.sub.max/seat
inclination S.sub.max, the greatest precurved deformation of the
link chain 41 results.
FIGS. 13A to 13C
[0146] In this case, a backrest support 40 of the second variant is
shown in the current upright zero position R.sub.0. The link chain
41 is configured as an integral plastics molded part which starts
at the very top with a top link 410, followed by successive links
411. On the final bottom link 411, an integral or joined-on
bridging link 42 is adjoined, which is rigidly connected to the
backrest connector 43, or may be configured integrally with the
backrest connector 43. By way of example, the link chain 41 is
extended in height and configured with a top part h. The movable
linkages between the links 410,411 and preferably also between the
lowest final link 411 and the bridging link 42 are formed by hinges
417--for example film hinges. In the top link 410, the upper fixed
point 415 is provided from which the guide 46 extends to the guide
opening 462 on the bridging link 42.
[0147] On the side remote from the seat part 3, rear stops 414 are
provided which block to the rear a bending of the link chain 41 at
the transition to the bridging link 42, remote from the seat part
3. The front stop 413 present on the link chain 41 on the backrest
support 40 of the first variant on the side facing the seat part
3--in order to block a precurved deformation counter to the load
effect, i.e. facing the seat part 3, beyond a maximum defined
mass--are not necessary on the backrest support 40 of the second
variant.
[0148] The upholstery supports 48 may extend integrally from the
respective link 410,411,42. The guide 46 for the longitudinally
displaceable embedding of the actuating element 47--from the upper
fixed point 415 through the top link 410, the entire link chain 41
and through the bridging link 42 to the guide opening 462--is
designed in such a manner and the actuating element 47 is such that
when pushed upwards, slippage by the deviation of the actuating
element 47 is avoided.
[0149] Each link 410,411 has in turn a drive element 412, which
engages in the next link 411 arranged thereunder, in order to pull
said link therewith into the precurved deformation. Whilst the
drive elements 412 in the backrest support 40 of the first variant
are formed from interlocking curved contours with an end stop, the
drive elements 412 in the second variant consist of a hook element
which pulls to the front said next link 411 inside a cutout in the
next link 411 with increasing precurved deformation of the
preceding link 410,411. The design and function of the actuating
arrangement 45 in the first variant thereof are unaltered.
[0150] The restoring spring which is required for adjusting the
backrest support 40 and the entire backrest 4 into the zero
position R.sub.0 when there is no load effect, may be formed
advantageously by the hinges 417 between the links 411. For
example, an elastomer with its dimensionally stable and resilient
characteristics is suitable for this purpose and a two-component
injection-molding method for producing the backrest support 40 may
be used efficiently. Alternatively, when there is no load effect,
the actuating element 47 effects the adjustment of the backrest
support 40 and the entire backrest 4 into the zero position
R.sub.0. In this case, the restoring effect of the actuating
element 47 may be reinforced by an additional resilient tractive
element. Said tractive element is fixed between the top link 410
and the bridging link 42, preferably on the rear face of the
backrest support 40 remote from the user.
[0151] As set forth in the sequence of FIGS. 7A-7E with the
backrest support 40 of the first variant, it may also be provided
in the backrest support 40 of the second variant, to achieve a
greater precurved deformation inside the link chain 41 in the upper
region thereof--substantially above the top part h--whereas this
reduces towards the bridging link 42. To this end, different
dimensioning and/or variable use of material inside the link chain
41 is conceivable. In this manner, the user leaning back into the
seat, from the shoulder upward, experiences an ergonomically
advantageous support oriented further towards him/her, partially
opposing the user. At the same time, areas of different rigidity
may also be configured inside the link chain 41 of the backrest
support 40 of the second variant in order, for example in the
lumbar region, to establish a greater deformation resistance on the
seat and to support the user more firmly in this body region. Also,
when applied to the backrest support 40 of the first variant,
within the link chain 41 different areas of curvature with variable
precurved deformation--effectively different radii of
curvature--and superimposed by curved areas, thus form different
areas of stiffness with variable deformation resistance.
FIGS. 14A to 14C
[0152] In the maximum inclined position R.sub.max, the top link 410
and at least the immediately following links 411 of the link chain
41 adopt their precurved deformation counter to the load effect.
The actuating element 47 acting on the upper fixed point 415
advancing toward the top link 410 with its drive element 412 has
pulled the adjacent link 411, the drive element 412 thereof moving
the next link 411 in the same direction. Depending on the
dimensioning on the seat, this sequence in the link chain 41
accordingly continues a considerable way in the direction of the
bridging link 42. With the precurved deformation between the links
410,411, the gap spacings between the rear stops 414 open up.
FIGS. 15A to 15E
[0153] This sequence of figures relates to the use of an actuating
arrangement 45' of the second variant for the backrest support 40
of the first variant according to FIGS. 1A-2C and 4A-7D or the
backrest support 40 of the second variant according to FIGS.
13A-14C. The receiver unit 459 on which the lower fixed point 458
for anchoring the actuating element 47 is located, is now in one
piece and has a slot 51 for receiving an axle pin 50 which is
longitudinally displaceable but fixed in terms of rotation in the
slot 51. The axle pin 50 extends on the connection axis D5, and
rests in the bearing elements 430 on the backrest connector 43. A
projection 52 with a wedge-shaped tip extends from the receiver
element 459 to the seat support 21, said tip being slidably applied
to an impact element 61 of an adjusting unit 6. From the fixed
point 458, the actuating element 47 with its portion a passes
through the intermediate space 460, penetrates into the lower guide
opening 462 of the guide 46, and extends inside the guide 46 to the
upper fixed point 415. The bridging link 42 is received unaltered
by the backrest connector 43. Apart from the impact element 61, the
adjusting unit 6 has the actuating member 62 which is supported on
the stop 211 present on the seat support 21 and, for example, is
configured as a screw. The adjusting unit 6 is articulated on the
rear axis D7. With a movable or resilient configuration of the
impact element 61, the articulation on the rear axis D7 might be
dispensed with and replaced by fastening to the rear to the seat
support 21. With a deeper insertion of the actuating member 62 into
the impact element 61, for example by screwing-in, the impact
element is moved towards the receiver unit 459, and said receiver
unit is thus pushed on the connection axis D5 with further
insertion of the actuating element 47 into the guide 46. This
effects a thrust onto the upper fixed point 415 on the top link
410, so that the link chain 41 is forced into a further precurved
deformation.
FIGS. 15A to 15C
[0154] In contrast, the backrest support 40 and the entire backrest
4 are located in the zero position R.sub.0, and with the current
adjustment on the actuating member 62, the axle pin 50 is located
to a maximum extent to the left in the slot 51 of the receiver unit
459. The seat support 21 with the mechanism 2 present here, with a
synchronous movement sequence between the backrest 4 and the seat
part 3, currently adopts the zero inclination S.sub.0.
FIGS. 15D and 15E
[0155] When moving the backrest 4 into the maximum rearwardly
facing inclined position R.sub.max, the backrest connector 43 is
lowered and at the same time drives the receiver unit 459. At the
same time, the projection 52 moves downwards on the obliquely
extending impact element 61, and as a result pushes the receiver
unit 459 on the axle pin 50 in the direction of the lower guide
opening 462, so that the actuating element 47 in the guide 46 is
pushed forward against the upper fixed point 415 and the link chain
41 thus successively achieves a greater precurved deformation. The
receiver unit 459 moves inside the slot 51 to the left via the axle
pin 50. By means of the mechanism 2 with synchronization between
the backrest 4 and the seat part 3, the seat support 21 is lowered
in the inclined position R.sub.max via the fixed first rotational
axis D1 and via the movable rotational axes D2,D3 to the rear with
the adjusting unit 6.
* * * * *