CA1316091C

CA1316091C - Seating furniture

Info

Publication number: CA1316091C
Application number: CA000613469A
Authority: CA
Inventors: F. Martin Steifensand
Original assignee: F MARTIN STEIFENSAND Firma
Current assignee: F MARTIN STEIFENSAND Firma
Priority date: 1988-04-12
Filing date: 1989-09-27
Publication date: 1993-04-13
Anticipated expiration: 2010-04-13
Also published as: ES2039580T3; DE3879679D1; EP0341344A2; EP0341344B1; EP0341344A3

Abstract

ABSTRACT OF THE DISCLOSURE

Seating furniture of the pivoting office armchair type having a pedestal rigidly secured to a seat holder and having seat and backrest pivotably connected to the seat holder by elastic connecting elements, wherein the pivoting out of an operating position, in which the rearward region of the seat is raised farthest upward and the backrest is pivoted farthest forward, into a position of repose, in which the rearward region of the seat is pressed farthest toward the rear, is effected by the body weight of the person seated, while conversely, pivoting out of the repose position into operating position is effected by use of the force stored in the elastic connecting elements.

Description

SEATING F~RNITURE

1 Field o~ the Invention:
The invention relates generally to seating ~urniture, i.e. chairs including armchairs and o~fice chairs wlth or without arm, and more particularly to a pedestal type office chair with synchronously coupled, pivotably adiusting seat and backrest, herea~ter sometimes called '^~eating furniture".

_ACKGROUN~ OF TlIE INVE~rION
Seatiny furniture o~ this type is already known. For example, a chair is known that has a pedestal with a firmly at~
tached pedestal block, a seat hold~r and a backrest holder. The seat holder is pivotably connected in its ~orward region to the pedestal blocX about an axis extending horizont~lly and trans-versely to the line of sight of a person sitting in the chair, ~5 while the backrest holder is pivotably connected to the ped~stal block and to the seat holder about second and third axes extending parallel to the aforementioned ~irst axi~ A pivotable connection o~ the backrest holder, and thus of the backrest as well, to the rearward end o~ the seat holder is provided.
In the previously known chair, the device~ for synchro-~ously coupled pivoting o~ the seat holder and backrest holder comprise the various piYotable connections between the pedestal block,:seat holder and backrest holderr and are ~urthermore embodied in such a way that pivoting of the seat holder and back-rest holder relative to the pedestal blocX takes place in each case in a common direction, yet the backxest holder passes through a larger pivoting angle than the seat holder does. ~oreover, pivoting downward/backward out o~ the operating position into tha ~3~6~

position of repose is effected by body weight. Contrarily, pivot-ing out o~ the position of repose upward/forward is effected by means of a force-storing element, for instance in the form of a gas spring, which is located underneath the seat holder and is braced between the pedestal block and the backrest holder.
In the previously known chair it is also provided that the first pivating axis of the seat holder on the pedestal block, the second pivoting axis of the backrest holder on the pedestal block, and the third pivoting axis o~ the backrest holde~ on the seat holder are located approximately on a straight line, or at least in the lateral regions of a middle straight line, in such a way that the circular arcs o~ the p~voting radii of the seat hclder and backrest holder on the third pivoting axis deviate only slightly from one another. The first pivot point of the :Eorward seat holder region on the pedestal block is embodied without play, while the third pivot point of the rearward seat holder end on the backrest holder is contrarily embodied with play. Both the seat holder and the backrest holder are relatively complicated and have a great number of individual components, thus requiring a corre-spondingly great number of screw connections, screw bolts, rivet connections, and the like to asse~ble them.

SUMMAR~ OF THæ INVENTION
Accordingly, an ob;ect of the present in~ention is to : provide improved seating furniture of the of~ice chair type.
A further object of the present invention is to provide improved seating furniture having a pedestal onto which a seat holder is attached, the seat holder being connected ~o both a seat and a backrest.
Another object of the present invention is to provide seating furniture simpler and less expensive in construction than the previously known seating furn~ture.
A still further object of the present invention is to provide seating ~urniture which is more erqonomically comfortable ~or the user.

1 3 ~

The objects of the present invention are realized in a preferred way by providing an o~fice type armchair having a pedes-tal onto which a seat holder is attached. A !;eat and backrest are connect.ed to the seat holder. The seat and backrest are synchro nously coupled for pivoting relative to the pedestal, sach in a common direction but with diferent pivo~ing angle ranges. The chair can pivot out at an operating posltion, where the raarward re~ion of the seat is raised farthest upward and the backrest is pivoted farthest forward, into a position Q~ xepose, in wh~ch the rearward region of the seat is pressed farthest downward and the backrest is pivoted the farthest toward the rear~ This pivot is e~fectuated by ths body weight of a person sitting on the seat furniture~ Convexsely, pivoting out of the position at repose upward/forward into the operating position is effected by means of a force-storing element, such as a gas spring.
The holder is secured rigidly, that is, substantially unpivotably, to the pedestal, and pivotable connections are pro-vided between the seat holder and the seat and also between the seat holder ~nd the backrest. The pivotable connections are embodied by torsionally elastic connecting elements.
The torsionally elastic connerting elements can also comprise torsion spring elements, which can be stressed both for flexing and for torsion and serve as force-storing elements. In a preferred manner, such torsion spring elements are embodied in the form of shackle springs, preferabl~ manufactured from spring steel bars. For each of these shackle springs, engagement points on the seat holder and the seat or seat frame, on the one hand, and on the seat holder and backrest or backrest frame, on the other, may be provided separately.~ :
In this respect, if the two torsionally elastic con-necting elements have initial spring tensions imposed upon them, the initial spring tension of each being contrary to the otherO
The different initial spring tensions, in ~act necessary here, are selected in particular in accordance with the restoring forces required to pivot the chair out o~ the position o~ repose into the operating position. As a result, the first torsionally elastic element, disposed between the seat holder and the seat or seat ~L3~6~

frame, has an initial tension adjusted in such a way as to corre~
spond to a seat alignment or seat inclination in which the forward region of the seat is lowered the most, or the rearward seat region is raised the most.
Contrarily, the second torslonally elastic connecting element, disposed betw~en the seat holder an~ backrest or backrest ~rame, ha~ an initial spring tension ~riente~ in the opposite direction and adjusted so as to correspond to an alignment or inclination of the rearward seat region and backrest, and hence a pivoted position, in which the rearward seat region is raised the most ~nd the backrest is pivoted the farthest forward.
In this respect, it is preferred for some constructions if at least one of the aforementioned initial spring tensions of the two torsionally elastic connecting elements is variable or adjustable. This makes it possible for instance for the two contrarily oriented spring initial tensions to be increased further if needed, and adjusted so as to pivot out of the oper-ating position into the position of repose, in which accordingly the rearward seat region is pressed the farthest downward and the backrest is pivoted the farthest backward. More force must be exerted by the person sitting in the chair, on the condition that at the same time the gas spring braced between the lower reg~on of the backrest and the upper region of the pedestal is relaxed by corresponding valve actuation.
It is understood that between these two extreme posi-tions, that is, the operating position and the position of repose, any arbitrary pivoted position of the seat and backrest can be adjusted virtually without gradation, and once the chair is in the ~esired pivoted position, it can be locked therein by actuation of the gas spring.
Advantageous options in disposing tha torsionally elas-tic connecting elements be~ween the seat or seat frame and the seat holder, and also between the backrest frame and the seat holder, can also be achieved according to the invention.
The foregoing and other objects and the nature and advantages o~ the present invention will appear more fully below ~ 3~6~9~

fxom a study of the following descr~ption and the appended drawi~gs.

BRIEF DESCRIPq~ION OF THE DRAWINGS
~he accompanying drawings, in which exemplary embodi-ments of the chair according to the present invention as well asits structural components are ~hown, will serve to further explain the inventio~, its further features an~ advantages. Identical parts and elements are always represented by the ~ame re~erence numerals.
Shown are:
Fig. 1, a schematic view, partly from the side and partly in section, of an office chair: ~
Fig. 2, a view from below o.~ the seat holder, substan-tially along the line II-II of Fiy. l;
Fig. 3, a schematic view from above on the seat holder, seat frame, and part of the backrest frame;
Fig. 4, a front view of the Pirst shackle spring, which is disposed between the seat holder and the seat or seat frame:
Fig. 5, a front view o~ the second shackle spring, which is disposed between the seat holder and the backrest or backrest frame Fig~ 6, a schematia perspectiv0 view of the frame parts forming the seat a~d backrest;
Fig. 7, a ~chematic view of a lever mechanism for actu-ating a gas spring, in order to lock the seat and backrest in agiven desire~ pivoted po~ition; and Fig. 8, a schematic side view of a further exemplary embodiment of seating furniture in the ~orm of a chair having a ~ree-swinging frame.
:
DET~IIED DESCRIPTION OF THE PREFERRED EMBODIMENT~
In Fig. 1, the side~view of an office chair can be seen, which has a pedestal 1, substantially comprising a tube, with a ~3~9~l supporting column 2, for instance embodied as a gas spring, dis-pose~ inside the pedestal 1 and on its upper end carrying a coni~
cal protxusion 3 that is insexted into a corresponding ~leeve 4 connected to a seat holder 5.
The lower end o~ the supporting column 2 o~ the pedestal 1 is supported on rollers ~not shown).
At the upper end of the pedestal 1, the seat holder 5 is joined or fixed firmly and substantially unpivotably to the sleeve 4 and to the outer tuba of the pedestal 1, for instance by welded to the upper end of the pedestal 1~
The seat holder S can be seen in detail in Fig. 2. It substantially comprises a tube 6 bent into a U having two legs 8, between which is a plate 7, joined firmly at its sides to the legs 8 and curved region o~ the U-shaped tube 6.
As can also be seen in Fig. 1, the plate 7 is also firmly joined to the upper ends o~ the sleeve 4 and outer tube o~
the pedestal.l, for instance by corresponding welded connections, and beginning at the pedestal 1 the seat holder 5 has an inclina-tion that is directed obliquely upward in the direction toward the front end of the seat surface.
Above the seat holder 5, the office chair substantially comprises a seat 43 with a seat frame 28 and a backres~ 45 with a backrest frame ~6, which has a lower backrest frame part 29 which defines a lower region 44 of the backrest 45. This lower backrest region 44 functions practically as a rearward region of the seat : surface, while the seat 43 practically functions as the front region of the seat surface (see also Fig. 6).
: As Figs. 3 and 6 show, the seat frame Z8 has two lateral first and second legs 28a and 28b, substantially parallel to one another, which are connectsd each via first and second swivel joints 30a and 30b to first and second 1QgS 29a and 29b, adjoining them, of the lower part 29 of the backrest frame 36, thereby enabling the seat frame 28 and backrest frame 36 to execute piv-oting motions relative to one another.
The upper portion of the office chair, substantially comprising the backrest 45 and armrests 3B, is not shown in Fig. 1 for reasons of space, but can be seen in Fig. 6. The two armrests ~3~91 38 extending from the seat frame 28 to the backrest frame 36 are provided with *lexionally elastic or flexible bending points, so that they can follow along with the relative pivoting motions of the seat frame 28 and backrest frame 3~ t the armrests 38 being connected at their respective ends, via correspondingly disposed swivel joints 39, with both the seat frame 28 and backrest frame 36. Such swivel joints 39 are for instance shown schematically in Figs. 1 and 6, which show tha pivotable connections of the arm-rests 38 to the two first and second legs 28a and 28~ of the seat frame 28 and to th~ two first and second legs 29a and 29b of the lower backrest frame part 29.
As can be seen particularly in Figs. 1 and 3, the seat holder 5 is connected to the legs 28a and 28b of the seat frame 28 via a first shackle sprlng 9. The seat holder 5 is also connected via a second shackle spring 15 to the legs 29a and 29b of the lower part 29 of the backrest frame 36. By means of these two first and second shackle spring~ 9 and 15, torsionally elastic pivotable connections are possible between the seat holder 5 and seat frame 28 (and hence the seat 43), and also between the seat holder 5 and the lower backrest frame part 29 (and thus the back-rest 45 as well~. The two shackle springs 9 and 15, which are preferably of spring steel and have initial spring tensions con-trary to one another, are each torsion spring elements, which are stressed for both flexion and tors~on, if the seat 43 and backrest 45 with the lower backrest region are pivoted in a synchronously coupled manner with one another, a~ already described in detail above.
In a preferred manner, the first shackle spring 9 has one fxee end 10 on each side, as shown particularly in Fig. 3, and these free ends of the shackle springs 9 serve to establish the connections with the seat frame 28. For this purpose, the free ends 10 of the shackle spring:9 are bent substantially parallel to the two legs 28a and 28b of the seat frame 28~ while a retaining element 11, ~or instance in the form of a receiving bush, is attached to each of these legs 28a and 28b and serves to secure a free end 10 of the shackle spring 9. Segments 9a and 9b, each bent at a right angle, also extend from these free ends 10 of the - ~L 3 1 6 ~) 9 ~31 ~3 r first shackle ~pring 9 as ~ar as the ends oriented toward the ~ront seat end of the seat holder 5.
In detail, the two legs 8 of the U--shaped bent tube 6 of the seat holder 5, which extend in the direct:ion toward the front end of the seat, each have a torsion hearing bush 12, which is associatsd with the ~irst shackle spring ~. The segments 9a and 9b of the first shackle spring 9, extending toward the seat holder 5, are rotatably supported at the level of the legs 8 in these torsion bearing bushes 12. Ad~oining these torsion bearing bushes 12, the shackle spring 9 is continued in the form of a ~ent middle portion 13, oriented toward the rearward region o~ the seat holder. This portion is for instance bent in a horseshoe-like shape and is movable relative to the seat holder 5, with the rearmost portion o~ the bent middle portion 13 supported in a lS~ sleeve 14. The plate 7 of the seat holder 5 has an opening 14', approximately in its middle, disposed precisely at the level of the rear section or rear end of the bent middle portion 13 and àssociated with an adjusting mechanism, to be described in detail below, for adjusting the i~itial tension of the first shackle spring 9.
The second shac~le spring 15 havlng an initial tension in the direction opposite the initial tension of the first shackle spring 9 is embodied in such a way that it has two free ends 16 extending parallel to the tw~ legs 29a and 29b of the lower back-rest ~rame part 29; these end~ serve to establish the connectionswith the lower backrest frame part 29 and thus simultaneously with the backrest frame 36.
Retaining elements 17, for instance in the form o~
receiving bushes, are attached to the two legs 29a and 29b in a manner similar to how retaining elements are attached to the two legs 28a and 28b of the seat frame 28. The free ends 16 of the second shackle spring 15 are secured in these retaining elements li. Adjoining these two free end~ 16 are obliquely extending segments 19 bent toward the seat holder 5, which then merge with a straight middle segment 20-connecting segments 19 to one another, opposite ~he bent middle portion 13 o~ the firæt shackle æpring 9.
Torsion bearing bushes 18 are di.sposed in the rear portion of each ~ 3~9~
g o~ the two par~llel legs ~ of the U-shaped tube 6 of the seat holder 5. These two torsion bearing bushes 1~ serve to provide rotatable support to the straight ~iddle portion 20 o~ the second shac]cle spring 15. The support of the second shackle spring 15 (see al50 Fig. 5) in the torsion bearing bus:hes 18 is thus equiva-lant to the rotatable support of the first s,hacKle spring ~see also Fig. 4) in the torsion bearing bushe~ 12.
As Figs. 1, 3 and 7 also show, the two first and ~econd legs 29a and 29b o~ the lower backrest frame part 29 are joined together by an intermediate frame part 31, the middle o~ which has a sleeve-liXe fastening element 32, which serves to brace an upper end 33l o~ a gas spring 33, as seen particularly in Figs. 1 and 7. On the other end, this gas spring 33, which is actuatable with the aid of an associated operati~ lever 35, .is braced with its lower end 33" on a rearwardly pointing arm 34 of the pedestal 1.
The gas spring 33 serves to lock the seat 43 and back-rest 45 in a given desired pivoted position within the pivoting range between the operating position a~d the position of repose of O
As shown in Fig. 7, the gas spring 33 has a valve 55 on its upper end 33l supported on the intermediate frame part 31, in particular in the form of an open/close valve, which can be aatu-ated with the aid of a lever mechanism 37 connected to the oper-ating lever 35 (see Pig. 7).
. This lever mechanism 37 exte~ding between the operatinglever 35 and the valve 55 is disposed partly on the intermediate frame part 31 and partly ~n a hollow space 31' of the intermediate frame part 31. The first segment o~ the lever mechanism 37, immediately adjoining the operating lever 35, pre~erably comprises a le~er arm 37' pivotably supported on the intermediate ~rame part 31. This pivotable support of the lev2r arm 37' is accomplished in the exemplary embodiment o~ Fig. 7 by providing the lever arm 37' with a curvature in the range of which a rotatable sleeve 46 is attached to the lever arm 37', the slee~e bei~g rotatably supported on a bearing tang 47. A ~egment of ~he lever arm 37~
adjoining the curvature protrudes through a recess 48 in the wall ~ 3 ~

of the intermediate frame part 31 into a hollow space 31' of the intermediate frame part 31, and at that end o~ the lever arm 37' there is a joint 4~ with which one end of a push rod 50, disposed in the hollow space 31', is pivotably connected. An actuating element 51 is connected to an end of the push rod 50 opposite from the joint 49. sy means o~ this actuating elemen 51, either the closed position or the opened position o* the valve 55 of the gas spring 33 is attained directly. To this end, the valve 55 has a valve tappet 56 with which the actuating element 51 c~operates.
In the exemplary embodiment of Fig. 7, the actuating element 51 is sub~tantially U-shaped and has an upper, ~ubstan-tially straight first finger 52 and a lower, second f~nger 53 having two bending points. These two bending points ara clisposed such that an inclined guide segment 54 of the second finger 53 of the actuating element 51 is created between them. Preferably, this inclined or sloping guide segment 54 is also adjoined by a straight segment of the second finger 53, which is located oppo-site and spaced by a short distance fxom the f irst finger 52 of the actuating element 51. The second finger 53 o~ the actuating element 51 has its surface in direct contact with a head 57 of the valve tappet 56 of the valve 55, ln such a manner that as a result o~ a displacement of the push rod 50 lnside the hollow space 31' of the intermediate frame part 31, the second finger 53 of the actuating element 51 and particularly of its guide segment 54 brushes past the head 57 of the valve tappet 56, thereby con-trolling it, so that the valve 55 of the gas spring 33 is actuated.
In other words, the valve tappet 56, with its head 57, slides along the inclined or sloping sur~ace of the guide segment 54, as a result of which the valve tappet 56, which is preferably under initial spring tension, is either pressed downward as a function of the relative displacement of the push rod 50 in the interior of the intermediate frame part 31, causing a relaxation of the gas spring 33 via the vaIve $5, or the valve tappet 56 is enabled to resume its uppe~most position again, in which the valve 55 is closed. Correspondingly, the operating lever 35, and thus ` ~3~60~1 the lever mechanism 37 connected with it, have, within a predeter-mined pivoting range 58, a firs~ (lower) position 58l, in which the valve 55 is closed and thus locking the instantaneous pivoted position of the seat 43 and backrest 45 set at that time. This is the locking position of the gas ~prinq 33 shown in Fig~ 7.
On the other side, the operating lever 35 and the lever mechanism 37 connected with it have a second ~upper) position 58"
located on the other end of the pivoting ran~e, as is also shown in Fig. 7. In this second position, the ~alve 55 oP the gas 10 spring 33 is opened, so that the seat 43 and backrest 45 of the office chair are pivotable in the manner described above, either by the wei~ht of the person's body or by the force-storing means (torsion spring elements).
As can also be seen from Figs. 1 and 2, a ~urther actu-15 ating rod linkage 21, substantially in the ~orm of a lever arm, is disposed on the underside of the plate 7 o~ the seat holder 5, remote from the two shackle springs 9 and 15. For the rotatable support of the actuatinq rod linkage 21, two bearing sleeves 22 are provided, which are, for instance welded, to one of the legs 8 20 of the U shaped tube 6.
The actuating rod linkage 21, which can he operated with a handle (not shown), serves to adjust the height of the support-ing column 2 belonging to the pedestal 1, and thus to adjust the : height of the entire chair, which~together with the upper, tubular 25 portion of the pedestal 1 is also supported rotatably with respect to the supporting column 2, so that the seating furniture shown here as an exemplary embodiment has the function of a swiveling office chair. The supporting column 2 is preferably embodied as a gas spring.
An adjusting mechanis~ 23 for adjustiny the initial kension of the first shackle spring 9 substantially comprises a housing 26 ~see Fig. 1), which is secured on the underside, remote from the first shackle spring 9, of the pla~e 7, precisely in the opening 14' in the plate 7O Also accommodated in the housing 26 35 of the adjusting mechanism 23 is an intermediate housing 27, with a bolt 25 supported in it, in such a manner that the intermediate housing 27 is axially displaceable relative to the bolt 25, and ~L 3 ~
. - 12 -the end of the intermediate housing 27 passing through the opening 14' cooperates ~ith the sleeve 14 in which the bent middle portion 13 of the first shackle sprinq 9 is supported. Furthermore, this adjusting mechanism 23 has a rotatable knob 24, in which the end of the bolt 25 remote from the middle poxtiorl 13 of the shackle spring 9 is secured. Turning the knob 24 to actuate it causes a relative displacement of the intarmediate housing 27 relative to the bolt 25, thus changing the position o~ the bent ~idd~e portion 13 of the first shackle spring 9 either upward or dvwnward, which is equivalent to adjusting the initial spring tension o~ the first shackle spring 9, which is in the opposite direction ~rom the initial spring tension of the second shackle spring 15. The adjusting mechanism 23 is also disposed in such a way that its axis is aligned obliquely to the axis of the pedestal 1.
Fig. 3 also shows that the s~at frame 28 $s covered with a per~orated plate 42, which in actuality fills the entlre space between the two seat frame legs 28a and 28b with a flat sur~ace.
A corresponding per~orated plate covering can also be provided in the region of the lower backrest frame part 29, if weight is put on the seat in this lower backrest region 44 as well. This kind of covering, using perforated plates 42, has the advantage over tha known shell constxuction6 of enabling very good activ2 venti-lation of the entire seat surface.
Fig. l;also shows the two extreme pivoted positions:
First, the operating position 40, in which the rearward region o~
the seat surface, or in this case the lower region 44 o~ the backrest 45, is raised farthest upward, while the backrest 45 is pivoted farthest forwa~d. By comparison, the position of repose is represented by the dashed-line curve 41, in which the lower region 44 of the hackrest 45 (and thus practically the rear seat-ing surface) is pressed farthest downward, and the backrest 45 is -piv~ted farthest backward.
The key concept o~ the invention is that torsionally elastic pivotable connections are provided, in particular in the form of torsion spring element~ as force-storing means, which makes a separate pivotable conneation possible between the seat and the seat holder, on the one hand, and the bacXrest and seat holder, on the other, while the seat holder itself is secured to the pedestal of the chair substantlally unpivotably~
Embodying the seating furniture according to the inven-tion not only improves the pivotability o~ the seat and backrest into the operating position but provides additiQnal elasticity in sitting as well, and particularly ~lexibllity on the side~ of the seating sur~ace; that is, depe~ding on the how the person sitting in the chair shifts his w0ight, flexibility to the right or left.
Fig. 8 shows a further exemplary embodiment of a piece of seating furniture, in the form of a chair 100 having a free-swinging frame 101. With thig Xind of free~swinging frame 101, aseat 102 and a backrest 103 are ~oined in a known manner, ~rmrests 104 are also provided on this free-swinging frame 101.
According to the invention, respective first pivotable connections 105 are now provided between the free-swinging frame 101 and the backrest 103 on the rear e~ds o~ the armrests 104.
The pivotable connections 105 are located at a lower level compar-ed with the upper edges of the armres$s 104. Respective second pivotable connections 107 are also provided between the ~ree-swinging frame 101 and the seat 102, in ~he region between ~he armrests 104 and a foot portion 108 of the free-swinging frame : lOl. The seat frame of the seat 102 and the lower Prame 112 of the backrest 103 are joined via swivel joints 106 in such a way that they can pivot relative to one a~other.
In a preferred manner,:the second pivotable~connections 107, which are provided between the free- winging frame lOl and the seat 10~, are now disposed on upper free ends of spring bars 109, which in turn are secured with their lower ends 110 to the free-swinging frame 101 and have an initial tension that ls equi~-alent to the operating position of the chair 100, in which the seat 102 is shifted farthest backward and the backrest 103 is plvoted farthest forwardO Pi~oting out of this operating position into a position of repose, in which the seat 102 is shifted far-thest forward while the backrest 103 is pivoted farthest backward, is effscted by the weiyht of a person seated in the chair 100, whil0 contrarily the seat 102 is shifted to the front counter to :1 3 ~

the spring force of the spring bars 109. The corresponding rela-tive pivoting motions o~ the seat 102 and backrest 103 are enabled by the first and second pivotable connectionS; 105 and 107 on the ~ree-swinging frame lol; these first and second pivotable connec tion~ are preferably embodied as swivel joint:s.
In a preferred manner, the upper ends of the two spring bars 109, which carry the second pivotable connections 107, are now supported oscillatably in gu~de elements 111, which have corresponding guide slits, that are provided on the free-swinging frame 101.
It may also be favorable, di~ferin~ from the exemplary embodiment shown in Fig. 6, for the frame of the backrest 103 of the chair 100 shown in Fig. 8 to be embodied with a less pro-nounced rearward ~lexion.
If a person seated on the chair in the position of repose shifts his weight forward again, then by means of the spring bars 109, which are subject to initial tension, the seat io2 and backrest 103 are pivoted back into the operating position, as already explained above~
` The foregoing description of the specific em~odiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing ~rom the generic concept, and~ therefore, such adapta-tions and modifications should and are intended to be comprehended within the meaning and range o~ equivalents of the disclosed embodiments. It is to be understood that the phraseology or~
terminology employed herein ~s for the purpose of description and not of limitation.~
~ .

Claims

WHAT IS CLAIMED IS:

1. Seating furniture in the form of a chair or arm-chair, comprising:
a pedestal (1), a seat holder (5) rigidly secured to said pedestal to prevent pivoting thereof, a seat (43) pivotably connected to said seat holder, a backrest (45) pivotably connected to said seat holder (5), a first elastic connecting element (9) providing connection between said seat (43) and aid seat holder (5), a second elastic connecting element (15) providing connection between said backrest (45) and said holder (5), wherein pivoting out of an operating position, in which the rearward region of the seat is raised farthest upward and the backrest is pivoted farthest forward, into a position of repose, in which the rearward region of the seat is pressed farthest downward and the backrest is pivoted the farthest toward the rear, is effected by the body weight of a person sitting on the seating furniture, while conversely pivoting out of the posi-tion of repose upward/forward into the operating position is effected by means of force-storing by the first and second elastic connecting elements.

2. The seating furniture of claim 1, in which the torsionally elastic connecting elements (9, 15) comprise torsion spring elements, which serve as force-storing elements.

3. The seating furniture of claim 1, wherein the torsionally elastic connecting elements (9, 15) are in the form of shackle springs.

The seating furniture of claim 1, wherein the torsionally elastic connecting element disposed between the seat holder (5) and the seat (43) has an initial spring tension that is directed counter to the initial spring tension of the torsionally elastic connecting element that is disposed between the seat holder (5) and the backrest (45).

5. The seating furniture of claim 4, wherein the initial spring tension of at least one of the two torsionally elastic connecting elements (9, 15) is adjustable.

6. The seating furniture of claim 1, further compris-ing a seat frame (28), provided for the seat (43), a backrest frame (36) having a lower backrest frame part (29), provided for the backrest (45), and wherein seat frame (28) is connected from its two legs (28a, 28b) to the seat holder (5) via the first shackle spring (9), while the lower backrest frame part (29) is connected with two legs (29a, 29b) to the seat holder (5) via the second shackle spring (15).

7. The seating furniture of claim 6, wherein the first torsion spring element (9) has two free ends (10), each bent substantially parallel to the two legs (28a, 28b) and secured by retaining elements (11) attached to the legs (28a, 28b), further comprising from the free ends (10) of the first shackle spring (9), at least two segments (9a, 9b) each bent at a right angle extending as far as the seat holder (5) and rotatably supported in torsion bearing bushes attached on the seat holder, and further comprising a bent middle portion (13), adjoining these two torsion bearing bushes (12), and oriented toward the rearward seat holder region, of the first shackle spring (9), which middle portion is movable relative to the seat holder (5).

8. The seating furniture of claim 7, wherein the second torsion spring element has two free ends (16), each bent substantially parallel to the two legs (29a, 29b) of the lower backrest frame part (29) and secured in retaining elements (17) attached to the legs (29a, 29b), obliquely extending segments (19) adjoining the two free ends (16) each bent in the direction toward the seat holder (5), which merge with a straight middle portion (20), connecting them, of the second shackle spring (15), and this middle portion (20) is located opposite the bent middle portion (13) of the first shackle spring (9) and is rotatably supported in two torsion bearing bushes (18) attached to the seat holder (5).

9. The seating furniture of claim 1, wherein the seat holder (5) further comprises a tube (5), bent into a U and a plate (7), filling the space between the outer walls of the U-shaped tube (6), wherein the two legs (8) of the U-shaped tube (6) point in the direction toward the front end of the seat and on each end have a torsion bearing bush (12) for the first shackle spring (9), while a torsion bearing bush (18) for the second shackle spring (15) is disposed in the rear region of each of the two parallel legs (8).

10. The seating furniture of claim 9, wherein the seat holder (5), along with its plate (7), has an obliquely upwardly oriented inclination, beginning at the pedestal (1), toward the front end of the seat surface.

11. The seating furniture of claim 9, wherein the plate (7) of the seat holder (5) has an opening (14') approximately in its middle region, which is disposed at the level of the rear end of the bent middle portion (13) of the first shackle spring (9) and is associated with an adjusting mechanism for adjusting the initial tension of the first shackle spring (9), which mechanism acts upon the portion of the bent middle portion (14) of the first shackle spring (9) that is located above the opening (14') and is supported in a sleeve (14).

12. The seating furniture of claim 11, wherein the adjusting mechanism (23) further comprises a housing (26), secured to the lower side, remote from the shackle spring (9), of the plate (7) and in which elements (25, 27), displaceable relative to one another in the axial direction, are accommodated, wherein this adjusting mechanism (23) furthermore includes a rotatable knob (24), by the actuation of which, via the elements (25, 27), a change in length of the bent middle portion (13) of the first shackle spring (9) upward or downward is effected, and thus an adjustment of its initial spring tension, which is oriented counter to the initial spring tension of the second shackle spring (15).

13. The seating furniture of claim 1, wherein on the underside, remote from the shackle springs (9, 15), of the plate (7) of the seat holder (5) an actuating rod linkage (21) is dis-posed, which is supported in bearing sleeves (22) and serves to adjust the height of the supporting column (2), for instance a gas spring.

14. The seating furniture of claim 1, further compris-ing a gas spring (33), coupled to an operating lever (35), pro-vided for locking the desired pivoted position of the seat (43) and backrest (5) in the pivoting range between the operating position and the position of repose, wherein this gas spring (33) is braced with its upper and (33') on an intermediate frame part (31) that connects the two legs (29a, 29b) of the lower backrest frame part (29) to one another, while the gas spring (33) is supported with its lower end (33") on the pedestal (1).

15. The seating furniture of claim 14, wherein the gas spring (33), in the vicinity of its upper end (33') braced on the intermediate frame part (31), has a valve (55) that is actuatable by means of a lever mechanism (37) connected to the operating lever (35) in such a way that in a first position of the operating lever (35), the valve (55) is closed and thus the instantaneous pivoted position of the seat (43) and backrest (45) adjusted at that time is locked, and in a second position of the operating lever (35), the valve (55) is opened, thus enabling the pivot-ability of the seat (43) and backrest (45) either by body force or by the force-storing element.

16. The seating furniture of claim 15, wherein the lever mechanism (37) is disposed between the operating lever (35) and the valve (55), partly on the intermediate frame part (31) and partly in a hollow space (31') in this intermediate frame part (31), and substantially comprises a lever arm (37') pivotably supported on the intermediate frame part (31) and a push rod (50) disposed in the hollow space (31') of the intermediate frame part (31), one end of the push rod being connected to the lever arm (37') via a link (49), and an actuating element (51) which cooper-ates with a valve tappet (55) of the valve (55) is disposed on the other end of the push rod.

17. The seating furniture of claim 16, wherein the actuating element (51) connected to the push rod (50) is U-shaped with an upper, first finger (52) oriented substantially linearly, and a lower, second finger (53) provided with flexing points, wherein these flexing points of the second finger (53) are dis-posed such as to provide between the flexing points an inclined guide segment (54) cooperating with a head (57) of the valve tappet (56), by means of which guide segment, as a result of displacement of the push rod (50) with the actuating element (51) in the interior of the intermediate frame part (31), the valve tappet (56) is controlled and thus the valve (55) is actuated.

18. The seating furniture of claim 1, further com-prising two armrests (38) each connecting the seat frame (28) to the backrest frame (36), via corresponding swivel joints.

19. The seating furniture of claim 1, wherein the seat frame (28) and the lower backrest frame part (29) are each covered with perforated metal sheets (42).

20. Seating furniture comprising a free-swinging frame (101), connected to a seat (102) and a backrest (103) and on which armrests (104) are included, further comprising first pivotable connections (105) between the free-swinging frame (101) and the backrest (103) provided on the rear ends of the back rests (104), and respective second pivotable connections (107) provided between the free-swinging frame (101) and the seat (102) in the region between the armrests (104) and a foot portion (108) of the free-swinging frame (101).

21. The seating furniture of claim 20, wherein the first pivotable connections (105) are located at a lower level than the upper edges of the armrests (104).

22. The seating furniture of claim 20, wherein the second pivotable connections (107) between the free-swinging frame (101) and the seat (102) are disposed on upper free ends of spring bars (109), which are secured with their lower ends (110) to the free-swinging frame (101).

23. The seating furniture of claim 22, wherein the two spring bars (109) are secured to the free-swinging frame (101) with an initial tension such that this initial tension is equiva-lent to the operating position of the chair (100) in which the seat (102) is displaced farthest to the rear and the backrest (103) is pivoted farthest forward, while the pivoting out of the operating position into the position of repose, in which the seat (102) is thrust the farthest forward and the backrest (103) is pivoted the farthest backward, is effected by the body weight of a person seated on the seating furniture (100), counter to the initial tension of the spring bars (109).

24. The seating furniture of claim 22, wherein the upper ends carrying the respective second pivotable connections (107) and the seat (102) of the spring bars (109) are oscillatably supported in guide elements (111) having corresponding guide slits and attached to the free-swinging frame (101).