AU551237B2 - Articulated chair - Google Patents

Description

AUSTIRALIA i Pritents A ct

DE CLARATION FOR A PATENT APPLICATION

W.J NSTRUCrfl0Ns (1)Int ~C~bovnin In 'Support of the convention application made by CASTELJI S.p..A. of applip~nt(s)

it vplcable (hereinafter called "applicant( for a patent We for an~ 11M TLso of invention entitled (d) CHAIR

AND addregs(eg) of I/W~~j LUIGI ROS:ELLO, managing Director of deCIA"n'fls (See hlndnote*) CASTELLI of Via Torreggiani Blologna, ITALY. do soleomnly and sincerely q4eclare as follows:

(or, -in the case of an aplbiicatlon by a body corporate) 1. T nm/We4- authorized fia make this declaration on behalf of the applicantN).

(or, where the applicant(s) is/are not the a,:'tual inventot-s)) AND adrcses) of 2. (f Ennio RizzQli. n4 ju ntrrts) Via della Repubblica 18, S. Lazzaro di Savena, Bologna ITALY

Itecitc' bow oppU. isN,-p the actual inventorN, of the invention kind the facts tipon which the applicantN wtvr Ns ctual irngtor(q) is/lqrq, entitled to rnalte the application are as follows:.

Pvplicant is the assignee of the inventor.

(Noto: Paragraphs 3 and 4 aply~ o idy to Convention applications) (111blett country, Olflaf date, ftnd The basic rpplicatiorNt) for patent or similar pru)tection on which the application is based (I 'Ipplicaut(q) llv ti;o!or VACH is/m idinifkcd by country, V-iog datc, taud basic applicantm as follows: Wit;, applicotion S Ita~y on 12 July# 1.983 by Castelli S.p.A.

4. The basic applications referred to In paragraph 3 hereof was/were the first npplkcatioxiNs made in a (Convention country in respect of the invention the subject of the application,

'-7 0~ 0"

Declared at 00 Bolog'aa Italy Inset: T)ATUC of Dated 1 1 8'

Notei No Wclizattll of~ te('ommlsi4$IDCr Of PatentS

rn-In4A~s ORMO$i\l~ FJ~CZPAThXCK P18/10/83 P18/101181 itent and Trade 'Mrsrk Attorneys 367 C ollins Street Meltxourne, Australia

I,

AUSTRALIAN PATENT ABRD' EN (19) AU, (11) AU-Br-30268/81

(54) ARTICULATED- CHAIR~ (71) CASTELLI S.P.A. -10268/84 551237 (22) 4.7 .84 (24) 12.7.83 V67755/83 (32) 12.7.83 (33) IT (3) 44) 2 4.4 86 (5i)3 A4'/r 1/024 (72) ENNIO RIZZ0L; (74) (56) 74505/81 A47C 1/032 23858/53 1$6,239 A47C 11/03? 4.5.1 EP 49,130 t'57) Several other embodiments within the scope of Claim 1 are doescri bed.

t 1x preentinveti~nte~ tx t a chair of the type( havrin-J a fixed1 VtructuZre alid a backreot and nezat, wh3cch are movable w.t~h xnpect to i~he said fixed

E~t~rnenai tvdios carried out b~y the Applicant have moreover shown that during backward reclining movement of the biackrot, it is necessary, in order to ao.hieve a oorreot postu~re and optimal cotnfort of the body of~ the seatod peraon, for the ba)ckrest to rotate around an articulation axis q;Ltuatod substantially at the seat loeve) and diraplacedl forwardly in relat$' n to the rear edgeo of the seat so that it coin:-;ideo rubsitantially wVth the artioulotior, ixiG betwen, the tbLA,,iin ind tho pelvi ,sof the lsooteo fioraon.

pinally it ircs~zy again. with a view to achieving themaimmposl oomfort, for the chair sc~at to inj(1int! bnrkwards at an angle lenthan tho 1 ii~if~tirt nglo ofthe hakrst.

14 1

11 5/7 /4) A/

4'

(11) AU-B-30268/84 -2-

Whe object of. the present'invention is to provide a chair of the type specified at the beginning of the present description, which will on the one hand make it possible to satisfy all the requirements described above and which will at the same time afford a relatively simple and economical construction.

CLAIM

A chair having a fixed structure and a backrest and seat which are movable relative to the said fixed structure, wherein the chair includes: a backre-t support articulated to the fixed structure around a first transverse axis, perpendicular to the vertical plane of symmetry of the chair, the said axis being situated substantially level with the seat and being positioned forwardly relative to the rear edge of the seat; stop means for limiting rotation of tht baXkrest support relative to the fixed structure of the chair, te said means defining for the backrest support, a forwardly rotated end position corresponding to an upright position of the backrest and a backwardly rotated end position corresponding to a reclined position of the backrest? resilient biassing means which bias the backrest support into its forwardly rotated end position, and a seat support articulated substantially adjacent its front edge to the fixed structure around a second transverse axis parallel to and positioned forwardly relative to the said :irst transverse axis, the said seat support being moreover connected to the backrest support generally in line with the roar edge of the seat,

./3

11S/74/41

Note', No te31i2t)I MA or other wilms

FIPHILLIPS QRrvONDE AND FITZPATRICK _----itfland Trade Mark Attorneys 367 Collins Street M4elbourne, Australia

-3- (11) AU-B-_O268/84

,in which the f ixed structure of the chair includes a cosspiece and two support bars projecting cantilever-fashion f orwardly from the -two ends of the crosspiece,~ in which the backrest support includes, two substantially L-shaped support arms each Connected at one end to a respective side of the backrest and articulated at its opposite end around. the said first, transverse axis to a respective end of the crosspiece, and in which the, seat support consists of two lateral support mnembers onnected to the two sides of the seat, aiid having their front ends articulated around the said second transverse axis to the two front en~ds of the said support bars and having their rear ends connected to the said L-'shaped support arms rea w-rdly of the said first transverse axis,

116/7 4/42

AUtfURALIA

Paternts Act

COMPLETE SPECIFICATION (ORTG ,A 4

Class Imt. Class Application Number: Lodged:

Complete Speoificatio ~nLodged: c,

Priority: al~~ndruL SRelated Art:

APPLICANT'S REF.:CS. 98 Cinerlati smo /ldb Name(s) ofA ,pplicant(s): CAST41LtJ SP-A-

Addross(es) of Applicant(s): Via Totregqlani 1, Bologna, Italy

Actual Inventor($)'. V-nnio RIZZOLI

Address for Service Is- PHILLIPS, QRMONtDE FITZPATRICK Patent and Trade Mark Attorneys 367. Collinis Street Melbourne, Australia, 3000 Coniplete Specification for the Invention entitled:

CHAIR

Tito following 6tatement 15 a full doeritionr of this- invontion, Incidng the bost method of' performing It known to aIpplieant(s):

P 10/11/17

The present invention relates to a chair of the type having a fixed structure and a backrest and seat which are movable with respect to the said fixed structure.

In chairs of the -bove type (see for example U.S. Patent 4,084,850) the backrest is movable from an upright position to a backward reclining position so as to allow the seated person to assume either an 0 00w erect working position or a resting, reclined position, 00L achieving the greatest possible comfort in both positions. ao i

0000c 'a 'ar (1000l A chair is already known (soe U.S.A. Patent 4,084,850 ref- C19

-erred to above) in which, when the backrest is moved into its backward reclined position, the seat is also inclined backwards, so as to counteract a possible tendency of the seated person's body to slip forwards. In this known solution, however, the front edge of the seat moves perceptibly upwards during the said inclining movement, pressing underneath the legs of the seated person at knee height and consequently preventing achievement of an optimal position from the point of vi~ of comfort.

Experimental studies carried out by the Applicant have moreover shovn that during backward redlining movement of the bac'krvet it is necessary, in o:der to achieve a correct posture and optimal comfort of the body of the seated person, for the backrest to rotate around an articulation axis situated substantially at the seat level and displaced forwardly in relation to the rear edge of the seat 9o that it coincides

SI-I I!

a seE substantially with the articulation axis betwe. n the its ftc thighs and the pelvis of the seated person. transvE Finally it is necessary, again with a view to achieving axis al the sa.- the maximum possible comfort, for the chair seat to incline backwards at an angle less than the backre., the re,, inclination angle of the backrest.

The sp

o 00 4? The object of the present invention is to provide a 4? 04? chair of the type specified at the beginning of tha betweei 4?u 4? 4? 10 suppor- 00 4? present description, which will on the one hand make 4? '4 0 0k,, 10 it possible to satisfy all the requirements described advant. 04? 4?4? backwa 0000 0 above and which will at the same time afford a 00 is pos

4? 4? relatively simple and economical construction. is dis With a view to achieving the said object,. the invention 15 of the provides a chair having a fixed structure and a backrest maximu Second and a seat movable relative to the said fixed structure, recl in characterised in that il comprises: a backrest support440'* to the fixed structure ha ckwa 20 body a

O 004? around a first transverse v05s perpendicular to the the an vertical plane of syr~metry Qf the chairt the said axis being situated substantially at the seat level that c and beingq4 "PIN4 forwardly in relation to the rear well, backw edge of the seat, stop means to limit rptation of the backrost support 25 positi relative to the fixed structure of the saat, the said said It due t( means Meining, for the seat support, a fopwardly rotated and position, corresponding to an uprirhL ponition of the backrest, and a backwardlyrotated end porition, ur th corresponding to a rec.lined position of the-- backrest, Aqil iert biassing meant whic.h tend to urfye tho backrvu t 30 inllU nupport towards its forwardly rotated end ponition, and

OQ f

A

a4 a seat support articulated, substantially adjacent its front edge, to the fixed structure around a second transverse axis, parallel to the said first transverse axis and i4- ee forwardly relative to the latter, the said seat support being moreover connected to the backrest support} s .Assp with the rear edge of the seat.

The special kinematic connection described above between the fixed structure of the chair, the seat support and the backrest support affords a number of advantages: firstly, when the backrest is reclined 'i backwards it rotates around an articulation axis which is positioned substantially at seat level and which is displaced forwardly in relation to the rear edge of the seat, so as to ensure correct posture and maximum comfort of the body of the seated person. Secondly when the backrest is moved into its reclined position, the seat is also inclined backwards, counteracting a possible tendency of the body of the seated person to slip forwards; however, S the angle of inclination of the seat is less than that of the backrest, which ensures, in this case as well, maximum comfort. Finally, the seat, in its backward inclining movement, rotates around an axis positioned in proximity to the front edge of the said seat, which avoids the abovementioned disadvantage due to excessive raising of the said front edge.

bemhy~c,according to the invention is chair further charactrised in that the fixed structure includes a crosspiece and two support bars projecting

4* fI

I

-4- cantilever-fashion forwardly from the two ends of the crosspiece, in that the backrest support includes two substantially L-shaped support arms, each joined at one end to a respective side of the backrest and articulated at the opposite end around the said transverse axis to a respective end of the crosspiece, and in that the seat support consists of two lateral support members joined to the two sides of the seat, and having their front ends articulated around 9 10 the said second transverse axis to the two front ends OB o of the said support bars and their rear ends connected C 0 to the two said L-shaped support arms rearwardly of the said first transverse axis. i 0 i 0

Further characteristics and advantages of the present invention will emerge from the following description referring to the accomnpanying drawings, supplied purely by way of non-iimiting example, in which; 0

Figure 1 is a perspective view of a first embodiment ""of the chair according to the invention;

Figures 2, 3 show on an enlarged scale a detail of Figure 1 in two different operative positions,

Figure 4 is an exploded perspective view, on an enlarged scale, of a detail of Figure 1,

Figure 5 is a sectional view along the line V-V of Figure I,

Figure 6 is a sectional view along the lino VI-VI of Figure

Figure 7 ii a sectional view along the lino VXI-VII of Figure,

A

Figures 8/'9 are two variants of Figures 5 whiCh centre show a~se.~ond. embodiment of, the chair according to th ':iiiention, In the fol Il0 Figures 10,111 show a thiri embodiment of the chair direct according to the invention, 5 is, ty chair Figures 12 to 14 show a fourth embodiment of the chair ref er according to the invention, l"tran.s 0 no 4 44 4 4~ 4 0 direct C C' 0 4 44 4 4 444)0 4 Figures 15 to 17 show a fifth embodiment of the chair 4)4)00 4) 10 symmet 4)4) 4 44 4 4) 4 40 00 according to the invention, and 4)4

44 4)4 4) 4) The b 4 4) P44))) 4044) 44 4)4) 10 Figures 18, A9 show a sixth embodiment of the chair 4) 04) conslm 4) 4 4 4) 4) 4) 4 according t! the invention. 8, ac re spec Figure I shows a chair 1 comprising a backrest. 3 and 15 each E 4444) a seat 4 movable relative to a fixed base structure 4)4) On to Lhc 4 C.4CC

2. o axis C, 4)) 4) 4)4)

In the example illustrated the fixnd. based structure 'rho cl 2 comprises two pairs of lateral legs 5, each pair 0, 6 04 in del being formed by a tubular element bent into a V 20 the al and disposed with the apex of the V upwards. V- will Elms' posit: be evident, however, that this particular type of base structure is shown in the accompanying drawings solely uprig) by way of example, It could be replaced by any other backw(, type of base structure, suchyfor example sas a pedestal 25 corre. including one single central support column or the like. There also As shown also in greater detail in the Figures 2, 3, the fixed structure 2 includes two support bars 6 projecting c Antilever fashion forwardly from the ends of a orose ,piece 7 which joins togethor tHe -wo pairts of latoral logs 5 (In the case of a bs structilre 30 conisting of a pedestal having a tiingle contral Csgpjjort: c"olumn, theospec 7 wouild be Joined at its

diSI)OS ~CMTtMS DII-TNING Tfll THE INVEN~TION AUP3 OLOWS,* b,-trs, centre to the upper endof the said support column).

In the present description and in the okiMS which follow, the terms "forwards" and "front"' refer to- the direction indicated by the arrow A in Figure 1, that is, the ditxaction in which a person seated on the chair faces. The terms "backwards" and "rear", refer to the opposite direction. Moreover, the terms "transverse" and "transversely" refer here to a direction perpendicular to the vertical plane of symmetry of the cha r.

oaf 0The backrest 3 is carriod by a backrest support consisting of two substantially L-shaped support arms 8, each of which is connected at its vpper end to a respective side of the backrest 3. Thie front and of each support arm 8, on the other hand, is articulated to the fixed structur e 2 of the seat around a transverse axis 9.

The chair is provided with stop means (which will be cup ribed in detail be low) to limit rotation of the arms 8 around the articulation saud9, in such manner that the said arms 8 can be moved from an extreme forwardly rotated VO position (shown in Figures 1, corresponding to an upright condition of the backrest 3 and an extreme backwardly rotated position (shown in Figure 3) corresponding to a reclined position of tbs backrest 3.

There are also provided resilient means (which will also bo-drecribed in detail below) which biav Wne suIpport arm6 8 of the bakrest 3 towards their forwardly rn Aed extreme positions (nee Figures It 2).

30 The seat 4 ir. carried by ii ieat- utkpporf; consi.sti sq of two lateral support members 10 connected respectively to the two sides of the seat 4. The two support members have their front ends articulaled, around a transverse axis 11, to the two, front ends of tho fixed support bars 6. The articulntion axis 11 is disposed adjacent tho front edge of the seat 4.

The rear ends of the two lateral supprt momberq are pivotally connected to the two L-shaped arms 81 substantially in proximity to the elbow thereof. As will be apparent, the connection of the rear ends of the support members 10 to the support arms H is effected by tho enghgement of a pin in a' olnt so as to allow correct miovement of the elomonto described above.*

uferring to Figurev 2, Re 3, when the neat ed person prep. us his back against the backrest 3, the' latter moves into its backwardly reclined position (see F~igure 3) against the action of tho reaillent meant which tend to keep It in the upright posiion. Upon movement of the arms 8,the zone of articulation of the oopport membero .10 to the arms 8 moves downwarda, inducing a backward inclination of the seat 4.

As is evidlent from the foregoing descriptjon. and from the accompanying d rawi ngs the axis 9 of articulation o the backrest auppc rt to the fixod struc ture of the chair is displaced forwaredly in relation to the rear edge of the seoat 41 thereby allowing a correct bnly posture for the seated par. on when the chair i put into the res t po~si tion with the baqkrest~ I reclined backwavdat At the name time, the special kinematic onflection dea~cril ed above, whic~h Joins togother Qv! backrest the chair, causes a backward inclination of the seat, which prevents the body of the seated person from sliding forwards when the backrest is tilted backwards, the inclination of the seat 4 being, however, less than the inclination of the backrest 3. Finally, since the seat 4 is articulated to the fixed structure of the chair substantially adjacent its front edge, ,Y the said edge does not move upwards when the seat. is inclined backwards, which allows maximum comfort for the seated person. On various embodiments of the chair according to the 'o invention which are shown in Figures 4 to 19 differ from one another mainly in the realisation of the resilient means which bias the backrest 3 to its upright position.

Referring to Figures 4 to 7, the crosspiece 7 consists of a channel section element having a vertcal lug 12 at each of its ends, 0V

As shown in Figure 6, eawh lug 12 is traversed by a cylindrical pivot pin 13 affixed to the said lug. That portion of the pin 13 which projects outwards from the lug 12 of the crosspiece 7 is fitted into a hole 14 in a fillet 15, substantially trianqular in shape, welded to the V-shaped tubular element which constitutes the two corresponding lateral legS at the apex of the V. To the lug 12 there is moreover affixed a dowel 1.6 which engages in a hole 17 in the fillet 15. The fillet fixed15 is removably to the pin 13 by a screw 18 which engages in a thrnaded hole made in the outer eni of the pin 1

An annular element 19 i; interposed between the head of the screw 18 and the fillet

8ach support bar 6 has a box section which includes two lateral walls 20 and an upper wall 21. The lateral 20 which faces the outside of tho chair is joined at its year end (see Figure 4) to the lug 12 of the crosspiece 7.

Also, each of the two support arms 8 has a box section1 including two lateral walls 23 and an upper wall 24.

A bush 25 is interposed between the two lateral walls 23 of each support arm 8 a~t thr V'rnt end of the arm, and is weldod to the said walls 23. The bush 2$ is rotatably mounted an that part of tho pin A3 which projects from the luq 12 towards the insido S1$ of the chair, with the interposition of an auxiliary bush 26. This auxiliary bush has alt one end an annular flango in contact with the luq 12, and its opposite~ end abuts a disc 27 finoo to the corresponding end of the pin 13 by a screw 2.8. The two walls 23 of each aupport arm 8 have two holoe 29 30 respectively vhich amrt.madato the auxiliary bush 26i and the disc 27 The bush 25 has a flat lateral surface (se vlqure

Within oaph riupport bar 61 in correspondence with the articulation axis 11 of the seait 4, the~re is fixed a transverse pin 31. More precisely, one end of the pin 31 in clamped by a grub screw 32 within a bush 33 welded to the no l of the bar 6 (see Viguro. 7). TVe pin 31 pansen through a hole 34 in the wall OPPosite the bush 33 and preoect cantilever- to0 fashion -towards the inside of the chair so as to act as a pivot pin for the support member 10 of the seat.

In the embodiment qhown, each support member 1.0 (see F~igures 6, 7) consist. of a channel. section element within which there is fixed, by screws 35, an insert olement 36 which has appendages 37a, 37b located in corresponding holes in the wall of the support member 10. The said insert BL~ment 36 has at its front end a hole, 38 for its articoulatod assembly on the end of the pin 31 projecting cantilever-fashion from the support bar G. Thle element 36 is loc)~ed on the pin 31 by an annular disc 39 fixed to the pin 11 by a crew

Adjacent the rear endl of each support member 10 the insert ceiont 36 has a slot 41 within which there Pi is nlidably mouinted a transverse pin 42 prO-"-,tinq towards, the nsd of the, chair from the Sluppowt arm 8. Tile pin 42 passe,,s through the wall 23 of the siupport arm G which fames towardn the insido of the chitir and has an enlarged lierid 43 weldeod to the s~aid wall1 23 on the inside of the spotarit 8. The insert ele!Iment 36 Is locked to the trantoverse pi~n 44 by a diso 44 fi) od on the fre~e end of the pin 42 by a screw

Within Ph supp ort har 6 there is. di spo.seOd a heol i-al. spring 46 4havirg ono end ho oked teo the pin :31 ond it,, opposiAte ml rigidly connected to a body 47 (se;e 5.'grhaving a threaded- axial hole. A threaded"( bolt Of actingq cis a tie barn engages in the hread4d oe oif the hody 47, tho head 49 of the bo xlt 4R eIunq ~Joined to the corsodn ~tpport. arm incline, backwards at an angle less thanR<the >inclination angle of the backrest, 2

12IAt~~-14 ANO SKt

in the manner described below. The bolt 48 is guided in a downwardly-open notch 50, made in a vertical Wall formi~g part of a bracket 51 welded within the fixed sluprt bar G,

The head 49 of the bolt 48 bears against a cylindrical element 52 which has a transverse hole for the paisago of-the bolt 41 and which is in contact with a wall 53 which formq pa~rt of a gusset element 54 weldod to the inside of the support arm 8. The wall 53 has a hole 55 thrQugh~which thle bolt 48 passes. In order to a.llow assembly of thie bolt 48, the element 54 has an 1 14 opening 56 in an inner vertical wall 57. Assembly of the dWHfOen parts described abov, is morreover facilitated by the fact that the box-section elements which corntitute the support barD 6 and the support arms 8 are open downwardly.

Refezrinq to Figures 4, 5, the upper wall 24 of each support arm G has, at the front end Rf the said arm, a downwardly-inclined portion 24A having a notch 24b open in which the respective bolt 48 engages.

The helical springs 46 constitute the resilient means described above which biaA the backrest support towards Ats forwardly rotated o~nd position, corresponding with the u.pright position of the backrest Bach helical spring 46 toAds infact to keep the head 49 of each bqlt 48 pe~d agai~nst the cyli~idrical element 52 which reots on, thie inrner wall 53 of thle respotive pupport arm 8. Coquoquently the latter is thrust towardu itn forward4 y rotnted anq position, which in~ del ied by rtontan'.t~ betWeenithe front portion

/j

115/74/41

12 24a of the wall 24 and the two rear edges, indicated in Figures 5, of the two lateral walls 20 of each support bar 6.

When the seated person presses his back against the backrest 3 so as to thrust it into its backward inclined position, the support arms 8 rotate about the articulation aixs 9 relative to the lugs 12 at the ends of the crosspiece 7. The centre of the cylindrical S0 element 52 therefore describes a circumferential arc about the axis 9 and consequently causes an increase in thedistance between the head 49 of the bolt 48 and the pin 31thus binging about an extension of the corresponding helical spring 46. The backwardly rotated extrema position of the support arms 8 is defined by the limit stop position of the pin 42 in the slot 41. The flat surface 25a of the bush 25 serves to allow the bolt 48 to move without the latter interfering with the bush

Following the rotational movement of the support arm 8 about, the articulation axis 9, the pin 42 to which the rear end of the seat support member 10 is joined moves downwardly, effecting a rotation of the support member 10 abouc the pin 31 carried by the support bar 6.

The embodiment of the chair according to the invention which is shown in Figures 8, 9 differs from that of Figures to 7 in that the resilient means biassing the backre;t towards the upright position consist of two springs 58 ea ch of which is disposed within the front end of Xhe rp.ectivi support arm 8 and is

116/74/42

1,,

13 helically wound around the pivot pin by which the support arr-8 is articulated to the lug 12 of the crosspiece 7. Each spring 58 has,moreover,one end 59 bearing against the lower surface of the wall 24 of the respective support arm 8 and one end 60 bearing against the inner surface of one of the two vertical walls of the channel-section crosspiece 7. A screw S61is screwed into this wall, the free end of the screw 61 being in contact with the end 60 of the spring S 10 58, so that the loading of the said spring can be t adjusted by the screw 61.

oaf Referring to Figures 10, 11 the embodiment shown in these drawings differs from the previously described embodiments irn that the resilient biassing means urging the backrest towards its upright position i-y consist of two helical springs 62, each of which is disposed, with its axis horizontal and parallel to the tB vertical plano of symmetry of the chair, within a widened end 7a of the channel-section crosspiece 7. One end of each spring 62 is in contact with an annular shoulder on a bush 63 engaged by a screw 64 which O* is located in a vertical wall 7b of the crossoiece 7 and which affords adjustment of the loading c. the spring 62. The opposite end of the spring 62 reacts against the bottom wall of a fork-shaped element 65 the wings of which are pivotally connected by a pin 66 (see also Figure 10) to one ond of a lever 67 which is fixed to the respective support arm 8 and which is itself articulated about the axis 9 to the fixed structure of the chair. Referring to Figure 11, when

41) The foltowipng staterneat is a full. description (if this, invention, including the best method of~ performing if known to1

appliantI

-14

the backrest is moved into its backward reclined po sition, the lever 67 rotates anticlockwise, causing compression of the associated helical spring

Referring to Figures 12 to 14, these drawings show an embodiment of the chair according to the invention which can be realised only when the fixed structuin of the chair includes two pairs of lateral legs 0 14Cot)consisting of tubular elements. In this embodiment .Q 10 the resilient means for biassing the backrest to its upright position consist of two helical springs 68, each of which is disposed within a respective lateral 14 leg S. The lower end of each spring 68 is connected to a body 69 slidably mounted within the leg 5 and having an axial threaded hole 70. The said leg 5 and the body 69 have a non-circular cross-section (see Figure 13) so as to prevent rotation of the body 69 wi.thin the leg S. A screw 71, engaged in the hole of the body 69, passes at its lower end through a ferrule 73 and engages a nut 72 welded to the latter. B3y adjusting the screw 71 the body 69 is adjusted in position within the l6g 5, causing a consequent variation of the loading of the helical spring 68. The upper end of the spring 68 is hooked to a transverse pin 74 the ends of whicl. are fixed to the two lateral walls' 23 of the respective support arm 8l.

in this embodiment, moreover, two discs 75 are welded to the opposite side8 of each tubular element of inverted V-ahapo formning each pair of lateral legs 5, at the apex of the V. Two aligned holes 76 are formed in the discs 75, their common. axis coinciding with the articulation axis 9. On to the two discs 75 there is welded a tubllar element 77 the ends of which are inserted into the holes 76. The -tubular element 77 pivotally supports, through the interposition of two bushes 78, a pin 79 to which the two lateral walls 23 of the corresponding backrest support arm 8 are fixed. The pin 79 has a head 80 which bears, through an interposed aher 81,against one wall 23 and is locked in position by a disc 82 which is fixed to the opposite end of the pin 79 by a screw 83 and which bears against the other wall 23 through a furthear washer 81. The two discs 75 have slots 84 (one of which can be seen in Figure 13) into which the transverse pin 74 fits slidably and to which is hooked the upper end of the associated helical spring 68. Obviously, the leg 5 also has an opening through which the pin 74 passes., Each support bar 6 is provided internally with a braaoke' 6_ welded to it and connected to a bracket 6f welded to the legs 'This facilitates fixing of the bar 6 to the legs

Referring to Figures 1.5 to 17, the embodiment of the chair according to the invention shown in these drawings differs from those previously described in that the resilient means for biassing the backrest to its upright position consist of a torsion bar 84 disposed within the crosspiece 7 and anchored at the centre to the central portion of the said crosspiece.

As shown i4 Figure 15, the torsion bar 84 has a U-shaped centre portion 85 which is located in a notch 86 -in an ancho;ing member 7 which a threaded has which projects 88. holeexternally of 7. 'The screw 89 has a shank A screw 89 engage^ in the said hole 88 and is housed within a central box-like portion 90 of the crosspiece 7. The screw 89 has a shank which projects externally of the; portion 90 and is connected by a diamtetral pin 91 to an adjusting knob 92. By operating the knob 92 it in possibl-e to vary the loading of the torsion bar 84.

Those portions of the torsion bar 84 which branch off °a from the centre portion 85 (indicated by the reference ,o 10 number 93) are rotatably supported on the bottom of the channel-section crosspiece 7, each by means of two bearing members 94 screwed to the crosspiece 7. The free ends 95 of the torsion bar 84 are, however,' disposed inside the respective support arms 8 of the backrest and bear against the inner surfaces of the upper walls 24 of tVt support arms 8.

r.Referring to Figures 18, 19, in the embodiment of the co chair according to the invention shown in these drawings, the resilient means for biassing the backrest to the upright position consist, on each side of the chair, of a series of leaf springs 96, substantially ao C-shaped, which bear, at their ends, against two counterposed walls 97, 98 fixed respectively to the support arm 8 and to the corresponding end of the crosspiece 7. The latter end is moreover provided with an internal cross pin 99 which engages in a slot 100 made in the support arm 8.

The chair akording to the invention, in its various illustrated embodiments, is designed more particularly as a chair for community use, for example, in meeting halls, theatrical hallU and the like. It is plain that the chair according to the invention can therefore be fitted, as generally occurs in the case of chairs of the type indicated above, with Smeans (of a kind Known per se) osigned to allow them to be joined together side-by-side with other chairs, and with mean,, for connecting to the said chair, easily and quickly, accessories such as arm rests and the like. Moreover,, the chair can be made, also as known per se, with a shape such as to allow it to be superimposed on other chairs of the same kind 0 0o 0 000 to form a vertical stack of minimal siz.

S©0 Naturally, with the principle of the invention remaining Qi

the same, details of construction and practical embodiments 0 15 can be widely varied relative to what has been described and illustrated purely by way of example, without nevertheless going beyond the scope of the present invention. 000 0 0 0 ~2 00 Li 0 Li 00

0000i' *0 00a 00 of lateral legs 5i (In the case of a base stru ture 30 The si consisting of a pedestal having a single central support column, the crosspiece 7 would be joined at its i

S dispos THE CLAIMS DEFINING' THE INVENTION ARE AS FOLLOWS: bars, 1. A chair having a fixed structure and a backrest and front seat which are movable relative to the said fixed structure, to one wherein the chair includes: to a r a backrest support articulated to the fixed structure coinci .around a first transverse axis, perpendicular to the vertical 3. plane of symmetry of the chair, the said axis being situated suppor substantially level with the seat and being positioned crossp forwardly relative to the rear edge of the seat; 10 which stop means for limiting rotation of the backrest wound support relative to the fixed structure of the chair, the ends b, S100 said means defining for the backrest support a forwardly suppor 0 Co' rotated end position corresponding to an upright position of 0 4.

400o° the backrest and a backwardly rotated end position oa has a j o corresponding to a reclined position of the backrest; i o0o means oOo resilient biassing means which bias the backrest one efi support into its'forwardly rotated end position, and Sthe c a seat support articulated substantially adjacent its lever front edge to the fixed structure around a second transverse 20 fixed axis parallel to and positioned forwardly relative to the being o o, said first transverse axis, the said seat support being o backre moreover connected to the backrest support generally in line 00 with the rear edge of the seat, includ Sin which the fixed structure of the chair includes a o0 tubula: '0 8 S crosspiece and two spport bars projecting cantilever-fashion 0^ means o u0 o forwardly from the two ends of the crosspiece, in which the latera o o. backres support includes two substantially L-shaped support o o lower o arms each connected alt one end to a respective side of the the le backrest and articulated at its opposite end around the said 30 supporl first transverse axis to a respective end of the crosspiece, 6. anc in which the seat support consists of two lateral support for ad: memxbers connected to the two sides of the seat, and having wit 111 rl their front ends articulated around the said second transverse axis t6 the two front ends of the said support bars and having the sa. their rear ends connected to the said L-shaped support arms forms I rearwardly of the said first transverse axis. into tl 2. Chair according to Claim 1, in which each of the said has a I support bars has a box-like body and in which the said has a f resailient biassing means include at least one helical spring Id

I

The seat 4 is carried by a seat support consisting I

disposed within the box~Klike body of one of the said suppo't consist of bars, the said helical spring having one end connected to the anchored a front end of the said support bar and the other end connected the ends o; to one end of a tie-bolt the opposite end of which is connacted supOrt ar to a respective backrest support arm in a zone which does ne 9. S coincide with the said first transverse articulation axis. provided w: 3. Chair according to Claim 1, in which each backrest torsion ba: support arm is articulated to the respective end of the position ii crosspiece through the interposition of a pivot pin, and in torsion ba: which the said resilient biassing means consist of a spring 10 10. Cha; wound spirally around the said pivot pin and having its two crosspiece ends bearing respectively against the respective backrest has two coi Ssupport arm and the respective end of the crosspiece. n means bias So°o 4. Chair according to Claim 1, in which the said crosspiece consist of oV has a box-like body and in which the said resillient biassing ends of wh a, means consist of at least one helical spring disposed within ooo 11. A c. one end of the crosspiece and having one end connected to a reference S the crosspieoe and its opposite end connected to one end of a 0 9, or Figu lever articulated around the said first transverse axis and 17 or Figu fixed to a respective backrest support arm, the said lever S being designed to compress the said helical spring when the 00D:

So° backrest support is rotated backwards. 0 5. Chair according to Claim 1, in which the fixed structure E4

D ,TED 7 includes two pairs of lateral legs each consisting of a o tubular element, and in which the said resilient biassing Patent Attl *oooo means consist of a helical spring disposed within one of the CASTI 0

S lateral legs of the chaix, the said helical spring having its Uoa' lower end connected to an anchoring element located within o 0

the leg and its upper end connected to a respective backrest support arm. 6. Chair according to Claim 5, in which means are provided for adjusting the position of the said anchoring element within the said leg. 7. Chair according to Claim 5, in which the upper end of the said kelical spring is hooked to a transverse pin which forms patt of the said backrest support arm and which projects into the inside of the said leg through a guide slot. 8. Chair according to Claim 1, in which the said crosspiece S has a box-like body and which the said resilient biasoing means ~44 4 C J''tW YJ) consist of a torsion bar disposed along thbi rosspiece and anchored at the centre of the central zone of the crosspiece, the ends of the torsion bar being connected to the two backrest sup ort arms. 9. S-eaLaccording to Claim 8, in which the crosspiece is provided with means for anchoring the centre portion of the torsion bar, the said anchoring means being adjustable in position in order to allow adjustment of the loading of the torsion bar. 10. Chair according to Claim 1, in which each end of the crosspiece and the corresponding support arm of the backrest has two contraposed surfaces and in which the said resilient /oo means biassing the backrest towards its upright position consist of at least one substantially C-shaped leaf spring the ends of which bear against the said contraposed surfaces, oo l11. A chair substantially as herein described with reference to and as shown in Figures 1 to 7, or Figures 8 and 9, or Figures 10 and 11, or Figures 12 to 14 or Figures 15 to 17 or Figure-, 18 and 19 of the accomn .nying drawings.

D.TED.- 7 November 1985 PHILLIPS ORMONDE AND FITZPATRICK Patont Attorneys fort C.ASTPXLl S.p.A.

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Claims (2)

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