CA1293683C - Seat furniture - Google Patents

Seat furniture

Info

Publication number
CA1293683C
CA1293683C CA000567773A CA567773A CA1293683C CA 1293683 C CA1293683 C CA 1293683C CA 000567773 A CA000567773 A CA 000567773A CA 567773 A CA567773 A CA 567773A CA 1293683 C CA1293683 C CA 1293683C
Authority
CA
Canada
Prior art keywords
backrest
seat
pivot axis
stand
linkage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CA000567773A
Other languages
French (fr)
Inventor
Egon Brauning
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Protoned BV
Original Assignee
Protoned BV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Protoned BV filed Critical Protoned BV
Application granted granted Critical
Publication of CA1293683C publication Critical patent/CA1293683C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • AHUMAN NECESSITIES
    • A47FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47CCHAIRS; SOFAS; BEDS
    • A47C7/00Parts, details, or accessories of chairs or stools
    • A47C7/36Support for the head or the back
    • A47C7/40Support for the head or the back for the back
    • A47C7/44Support for the head or the back for the back with elastically-mounted back-rest or backrest-seat unit in the base frame
    • A47C7/445Support for the head or the back for the back with elastically-mounted back-rest or backrest-seat unit in the base frame with bar or leaf springs

Abstract

Abstract A seat (2) is mounted pivotably about a first axle (A1) on the stand (1) of the chair. The seat frame (8) is connected to a second axle (A2) which is fastened to the backrest (3) behind the backrest (3) at a horizontal distance from the latter and at a vertical distance from the first axle (A1).

The backrest (3) produced from an elastically resi-lient material, when deflected out of its vertical posi-tion, causes the second axle (A2) to move over an arc of a circle of radius A1 - A2; the rear seat portion ad-jacent to the backrest (3) is also lowered corresponding-ly thereby. The backrest (3) extending over the entire height of the chair forms with its lower portion an in-tegral component of the chair stand (1).

In comparison with the known complicated and heavy backrest/seat adjustment mechanisms, a cost-effective and lightweight construction, but one which fully satisfies modern ergonomic requirements as regards sitting comfort, is proposed here.

(Figure 1)

Description

~936~3 The invention relates to seat furniture.
It is a known fact that sitting in a specific sitting pos:ition for a relatively long time soon causes fatigue, and that every seated person therefore generally tends to vary his position from time to time. Although these changes of position involve primarily the angular adjustment of the backrest, it has nevertheless been shown that any rearward pivoting of the backrest should be in con~unction with a corresponding adjustment of the seat, if it is not to lead to an ergonomically unacceptable position. According to experience, only in this way is it possible for the human body, when seated, to be supported in such a way that it can sit for a relatively long time without fatigue in all the possible positions of the backrest.
The de6ign of the seat-surface/backrest adjustment mechanism made necessary because of this has already given rise to numerous constructions which therefore all have the aim of lowering the rear seat portion adjacent to the backrest by an appropriate amount during the rearward pivoting of the backrest, so that the seated person does not risk slipping forwards in the ~0 new position. However, these known constructions are based entirely on the use of lever mechanisms with steel springs andJor pneumatlc springs, so that the chairs known at the present time and meeting the above-mentioned criteria are not only complicated in terms of construction, but also costly and relatively heavy.
~ The object of the present invention ls to provide a seat - furniture, which although having the coupling of the adjusting movements of the seat and backrest desirable for ergonomic A

6~3 . 2 20152-118 reasons, nevertheless, makes do without the known expensive and heavy adjusting and catching mechanisms. At the same time, the functional coupling of the seat and backrest, referred to as "synchronous" in the art, is, if possible, to be achieved so that, on the one hand, the rear seat-surface portion adjacent to the backrest is lowered only when the seated person presses the backrest rearwards and, on the other hand, the backrest maintains its vertical position, irrespective of the load to which the seat surface is subjected, as long as there is no direct exertion of force on the latter.
The invention provides seat furniture, comprising a stand having a forward section, a rearward section and a first pivot axis located on said forward section at a first elevation; a seat having a front end and a back end; a backrest having an upper end, a lower end fixedly attached to said rearward section of said stand, a front side facing toward said seat, a back side facing away from said seat, and an elastically resilient portion extending from said lower end of said backrest to a point on said backrest located at a second elevation which is higher than said first elevation, said backrest being arranged in a rest position in which said backrest is oriented substantially vertically and said backrest being deflectable out of its said rest position in response to a force exerted against said fron~ face of said backrest by an individual sitting on said seat; connecting means movably mounted on said forward section of said stand for connecting said seat to said backrest in such a manner that said back end of said seat pivots downwardly in response to the A~

125~3~i83 ,,~,,~
2a 20:~52-1184 deflection of said upper end of said backrest away from said forward section of said stand, said connecting means including an angular linkage extending between said first pivot axis and a second pivot axis positioned adjacent to said back face of said backrest at a third elevation which is higher than said first elevation but no higher than said second elevation, whereby said elastically resilient portion of said backrest is located below said second pivot axis, said linkage including a first end which supports said front end of said seat and which is pivotable about said first pivot axis and a second end which is pivotable about said second pivot axis; and supporting means fixedly attached to said back face of said backrest for supporting said second end of said linkage, said supporting means including said second pivot axls, whereby said second end of said linkage is pivotally connected to said supporting means in such a manner that said second end of said linkage pivots about said second pivot axis as said first end of said linage pivots about said first pivot axis to thereby permit the synchronous movement of said backrest and said seat.
The invention is based on the surprising perception that the functions of known adjusting mechanisms can be incorporated in the basic chair parts, namely the stand, seat and backrest, in such a way as to result in a cost-effective and lightweight seat furniture which can completely satisfy the known ergonomic requirements as regards sitting comfort, without being burdened with the disadvantages of the known mechanisms.

1~3683 2b 20152-1184 Some exemplary embodiments of the subject of the invention are described below with reference to the accompanying drawing.
Figure 1 shows a simplified perspective view of a first embodiment of the seat furniture according to the invention, before the upholstery is attached, Figure 2 shows a vertical section through this embodiment, Figure 3 shows a perspective representation of an alternative version, and . .

125~36~3 Figure 4 shows the corresponding representation ;n vertical sect;on.

The chair illustrated in Figure 1, with non-essentiaL
details omitted, consists of a stand 1, a seat 2 and a S backrest 3. The stand 1 has essentially two approx;mately rectangularly bent feet 4 which are formed from tubular sections and which carry a first pivot axle A1 on the front side of the chair. In this embodiment, the stand also includes the lower portion 3a (Figure 2) of the back-1~ rest 3, this portion 3a being connected to the feet 4 viaa crossmember S and thus forming an integral component of the stand.

In this first embodiment, the backrest 3 is a plas-tic plate 6 extending over the entire height of the chair and reinforced with two longitudinal steel strips 7 which are fastened flex;bly at the;r lower ends to the cross-member 5. As a result of this construction, the backrest 3 has a specif;c elastic res;lience, so that it yields under load and automatically resumes its orig;nal position when relieved. As will also emerge from the following description, this elastic spring effect is necessary, above all in the lower backrest portion 3a.

The seat designated as a whole by 2 has a virtually U-shaped frame 8 which, for example, can likewise be pro-duced from a tubular section and which is mounted rotat-ably in a tubular crossmember 9a by means of two pivoting shackles 9 in the region of the front seat port;on and at a distance c from the front edge of the seat. The seat - thus forms a kind of two-armed lever with the front lever arm c and the rotary axle A1. As Figures 1 and 2 also show, the seat frame 8 éngages behind the backrest 3 and on its rear side is connected to the backrest 3 by means of a second pivot axle A2. This second pivot axle A2 on the one hand is fastened rigidly to the rear side of the backrest 3 by means of a bracket 10 and on the other hand, lZ~3683 on its two end portions, carries two connecting links 11, on which the rear portion of the seat frame 8 is suspended.
The two connecting links 11 are thus mounted rotatably about the axle A2 and perform the function of transmitting S any movement of the backrest 3 to the seat frame 8.

The second pivot axle A2 is located at such a ver-tical distance b from an imag;nary hor;zontal plane pass-;ng through the axle A1 that ;t is approximately level w;th the lumbar vertebrae of the seated person. Further-more, there should preferably be a horizontal d;stance a between the axle A2 and the backrest 3 which can be, for example, between 5 and 20 cm.

The following result ;s obta;ned when the cha;r des-cr;bed ;s used:
, After the seated person has ;nitially remained for a certain time in the vertical sitting Position corres-ponding to the contours of the seat/backrest combinat;on which are represented by unbroken lines in Figure 2, ac-cord;ng to experience he w;ll feel the need to adopt another sitting posit;on by adjust;ng the backrest 3. If, as normally occurs, a load is exerted on the backrest 3 in the region of the lumbar vertebrae (the arrow ~ in ; Figure 2), as a result of its inherent elastic;ty ;t bends rearwards into the pos;tion represented by broken lines.
At the same time, the axle A2 describes an arc of a cir-cle of radius A1 - A2 and lowers the rear seat portion adjacent to the backrest 3 by a corresponding amount. The seated person has thus found a new sitting position which meets ergonomic criteria.
,~
The chair ;llustrated in Figures 1 and 2 is only one possible embodiment which a person skilled in the art can mod;fy ;n many respects w;thin the scope of the invent;ve ;dea. Thus, although it may be advantageous, for the purpose of obta;ning a simple design, to lengthen the lZ936~;~

illustrated backrest 3 downwards in one piece and fasten it to the lower stand element, it would nevertheless also be possible to mount the backrest on the stand approxi-mately level w;th the seat plane and there either fasten S it flexibly to a crossmember or articulate it by means of a further horizontal axle. At all events, however, at least that portion of the backrest 3 which e~tends from the fastening point of the axle A2 to the lower clamp;ng point of the backrest 3 should be made elastically resi-lient. An appropriate elastic restoring force can beachieved by producing the backrest 3 from plastic, steel or a combination of different materials.

It must be considered a decisive advantage of the construction described that, on the one hand, the chair makes do with an extremely simple seat/backrest adjust-ment mechanism requiring no helical springs or pneumatic springs and therefore resulting in a lightweight seat furniture which can be produced cost-effectively, whilst on the other hand the functioning thereby obtained cor-responds to an absolutely top-quality solution in terms of sitting comfort.

A modification of the inventive idea is shown in Figures 3 and 4, here too the upholstery not being shown for the sake of clarity. In this case also, the three basic units, that is to say a supporting stand 11, a seat 12 and a backrest 13 can be distinguished on the chair. The commercially conventional stand 11 equipped with castors 14 carries a crossmember 15 designed in the form of a steel section and fastened rigidly to the stand top part.

The crossmember 15, at its front edge, carries a pivot axle A1, on which the seat 12 is suspended in such a way that, here too, it can execute a rocking movement about the axle A1 in the manner of a two-armed lever.
However, in contrast to the embodiment illustrated in lZ5~3683 Figures 1 and 2, here the longer seat portion is canti-levered, that is to say not connècted to the backrest.

The backrest 13, which again can consist, for example, of an elastic plastic plate 16 and reinforcing steel strips 17, is anchored at its lower end on the crossmember 15 in such a way that it can pivot about an axle A3 located on the crossmember. Here too, a pivot axlr A2 is fastened to the rear side of the backrest 13 at a distance b above an imaginary horizontal plane passing through the axle A1 (corresponding to the position of the lumbar vertebrae) and at a distance a from the backrest itself. An actuat-ing rod assembly 18 engages on th;s pivot axle A2, ex-tends from the front seat portion on both sides and above the seat and thus at the same time forms, on the one hand, the armrests of the chair, and, on the other hand, the connecting member between the backrest and seat.

The actuating rod assembly 18 comprises two actuat-ing levers which start from the pivot axle A1 and which are fastened on both sides of this rigidly to the under-side of the seat. The axle A1 can be, for example, atube in which the ends of the two actuating levers 18 are mounted rotatably.

; In this embodiment too, when a load is exerted on the backrest the latter will be deformed (see the contour represented by broken lines) in such a way that the axle A2 is lowered by a corresponding amount, since it moves over an arc of a circle of radius A1 ~ A2. This lowering movement of the axle A2 is now transmitted via the armrests 18 to the front seat portion which rises slightly and thereby gives rise to the desired lowering movement of the rear seat portion. The convexity of the backrest in the lower backrest portion 13u ~Figure 4), associated with the bending of the backrest, is absorbed as a result of the arrangement of the axle A3.

` ~ 36~3 The axles A1, A2 and A3 illustrated by ~eans of Figures 1 to 4 can be designed in a known way, for example as pivots, hinges, etc., by a person skilled in the art.

Claims (9)

1. Seat furniture, comprising a stand having a forward section, a rearward section and a first pivot axis located on said forward section at a first elevation; a seat having a front end and a back end; a backrest having an upper end, a lower end fixedly attached to said rearward section of said stand, a front side facing toward said seat, a back side facing away from said seat, and an elastically resilient portion extending from said lower end of said backrest to a point on said backrest located at a second elevation which is higher than said first elevation, said backrest being arranged in a rest position in which said backrest is oriented substantially vertically and said backrest being deflectable out of its said rest position in response to a force exerted against said front face of said backrest by an individual sitting on said seat; connecting means movably mounted on said forward section of said stand for connecting said seat to said backrest in such a manner that said back end of said seat pivots downwardly in response to the deflection of said upper end of said backrest away from said forward section of said stand, said connecting means including an angular linkage extending between said first pivot axis and a second pivot axis positioned adjacent to said back face of said backrest at a third elevation which is higher than said first elevation but no higher than said second elevation, whereby said elastically resilient portion of said backrest is located below said second pivot axis, said linkage including a first end which supports said front end of said seat and which is pivotable about said first pivot axis and a second end which is pivotable about said second pivot axis; and supporting means fixedly attached to said back face of said backrest for supporting said second end of said linkage, said supporting means including said second pivot axis, whereby said second end of said linkage is pivotally connected to said supporting means in such a manner that said second end of said linkage pivots about said second pivot axis as said first end of said linage pivots about said first pivot axis to thereby permit the synchronous movement of said backrest and said seat.
2. Seat furniture according to claim 1, wherein said first end of said linkage includes a first link member and wherein said second end of said linkage includes a second link member arranged at an angle relative to said first link member and rigidly attached thereto, said second link member extending downwardly from said supporting means, whereby said linkage is suspended from said supporting means.
3. Seat furniture according to claim 2, wherein said first link member extends below said seat on opposite sides thereof.
4. Seat furniture according to claim 2, wherein said first link member extends above said seat on opposite sides thereof, whereby said first link member may also function as armrests for said seat furniture.
5. Seat furniture according to claim 1, wherein said lower end of said backrest is attached to a cross-member bridging a lower end of said stand.
6. Seat furniture according to claim 6 wherein said backrest is pivotable about a third pivot axis which passes through said lower end of said backrest.
7. Seat furniture according to claim 1, wherein said backrest includes an elastically resilient plastic plate reinforced by vertically arranged steel strips.
8. Seat furniture according to claim 1, wherein said second pivot axis is spaced horizontally from said back face of said backrest.
9. Seat furniture according to claim 1, wherein said back end of said seat projects rearwardly from said forward section of said stand in a cantilever-like fashion.
CA000567773A 1987-06-09 1988-05-26 Seat furniture Expired - Fee Related CA1293683C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH2161/87A CH672882A5 (en) 1987-06-09 1987-06-09
CH2161/87 1987-06-09

Publications (1)

Publication Number Publication Date
CA1293683C true CA1293683C (en) 1991-12-31

Family

ID=4227301

Family Applications (1)

Application Number Title Priority Date Filing Date
CA000567773A Expired - Fee Related CA1293683C (en) 1987-06-09 1988-05-26 Seat furniture

Country Status (9)

Country Link
US (1) US4880272A (en)
EP (1) EP0295214B1 (en)
JP (1) JPS63317104A (en)
AT (1) ATE67381T1 (en)
AU (1) AU599292B2 (en)
CA (1) CA1293683C (en)
CH (1) CH672882A5 (en)
DE (2) DE8806924U1 (en)
DK (1) DK310488A (en)

Families Citing this family (19)

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US5383712A (en) * 1988-04-25 1995-01-24 Perry; Charles O. Flexible chair
IL97762A (en) * 1990-04-10 1994-08-26 Perry Charles O High density stacking flex chair
EP0584069B1 (en) * 1990-10-01 1998-05-20 Achim Steinmeier Dismantlable chair
DE4236834C2 (en) * 1991-11-02 2002-09-05 Gotthard Bresch seating
DE4210282C1 (en) * 1992-03-28 1993-04-01 Martin Stoll Gmbh, 7890 Waldshut-Tiengen, De
AU7244294A (en) * 1993-06-02 1994-12-20 Sava Cvek Articulated support chair
ES2110874B1 (en) * 1994-04-21 1998-11-16 Jevit Manufact Metalicas Sa SEAT FURNITURE.
DE4428244A1 (en) * 1994-08-10 1996-02-22 Desanta Chair connectable into row of seats
US6224159B1 (en) 1999-05-12 2001-05-01 Charles Owen Perry Flexible chair which can be disassembled to a flat configuration
US6412869B1 (en) 1999-05-27 2002-07-02 Steelcase Development Corporation Nestable synchrotilt chair
FI108842B (en) * 1999-11-17 2002-04-15 Martela Oyj Chair
EP1357822A1 (en) * 2001-01-31 2003-11-05 Radmilo Eric A self-adjusting general-purpose chair with a cantilever type seat fixed on the front side of the seat
US7226127B1 (en) * 2005-12-21 2007-06-05 Tk Canada Limited Ergonomic chair backrest
US7806478B1 (en) 2006-01-04 2010-10-05 Sava Cvek Task chair with dual tilting capabilities
US9480339B2 (en) 2012-12-31 2016-11-01 Sava Cvek Seat with pelvic support
US11266244B2 (en) * 2018-02-16 2022-03-08 Barrett Studios, Inc. Chair assembly
FR3081691B1 (en) * 2018-06-01 2022-11-04 Martin Veith CHAIR WITH IMPROVED COMFORT
DE202018103738U1 (en) * 2018-06-29 2019-10-09 Armin Sander Seating, in particular free-swinging chair
IT202100006467A1 (en) * 2021-03-18 2022-09-18 Pro Cord Spa CHAIR WITH OSCILLATING SEAT AND BACK

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE88021C (en) *
US2557671A (en) * 1951-06-19 Mcdonald
US169065A (en) * 1875-10-19 Improvement in chairs
AT147750B (en) * 1935-01-21 1936-11-10 Hermann Franz Donath Seating.
DE675688C (en) * 1936-03-26 1939-05-13 Andreas Gaal Cantilever seating and reclining furniture frame
US2439869A (en) * 1944-11-14 1948-04-20 Renwick J Sharp Adjustable spring supported chair
DE832053C (en) * 1950-12-24 1952-02-21 Paul Bode Frame for seating such as armchairs and chairs
US2961035A (en) * 1954-05-26 1960-11-22 Lorenz Anton Article of repose for supporting the body of a person
FR77026E (en) * 1957-10-09 1962-01-08 Seat or other items such as sofa, etc.
DE3372059D1 (en) * 1983-10-05 1987-07-23 Giroflex Entwicklungs Ag Chair with an inclinable seat and back-rest

Also Published As

Publication number Publication date
EP0295214B1 (en) 1991-09-18
JPS63317104A (en) 1988-12-26
ATE67381T1 (en) 1991-10-15
AU599292B2 (en) 1990-07-12
EP0295214A1 (en) 1988-12-14
DK310488A (en) 1988-12-10
DK310488D0 (en) 1988-06-08
DE8806924U1 (en) 1988-07-07
DE3864913D1 (en) 1991-10-24
CH672882A5 (en) 1990-01-15
AU1666088A (en) 1988-12-15
US4880272A (en) 1989-11-14

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