A CHAIR

Abstract: A chair comprises a seat device (1) pivotably supported on a base (2) about an axis (3). A back rest (4) is pivotable relative to he seat device (1) about a second axis (5). Power means (6) is adapted to actuate the seat device (1) and back rest (4) to pivot the seat device into a forwardly inclined position. The seat device comprises a seat frame (18) and a seat member (19) forming a seat surface, said seat member being pivotable relative to the seat frame by means of an operating device (22) so that pivoting forwardly of the seat frame involves pivoting upwardly of the seat member. However, the operating device can be put out of operation by means of a control device (28).

Description: A-chair TECHNICAL FIELD AND PRIOR ART This invention is related to a chair of the kind defi¬ ned in the preamble of claim 1. Such a chair is disclosed in the US patent 3 851 917. Although this chair is advantageous in that it simpli¬ fies rising from the chair, it does, however, have some disadvantages. As an example, it may be mentioned that pivoting of the seat member relative to the seat frame does not always give adequate assistance on rising. Furthermore, it would be desirable to be able to widen the field of use of the chair so that a person sitting in the chair would be able to manoeuvre himself verti¬ cally without having to rise- from the chair. SUMMARY OF THE INVENTION The object of the invention is accordingly to widen the field of use of the chair mentioned hereinabove. This object is obtained by the features in the characterizing portion of claim 1. The advantage with such a construc- tion is that the chair, when the operating device tempo¬ rarily has been put out of operation, maybe adjusted in¬ to such a position that a person sitting in the chair may be moved directly to erect position or at least a position in which the knees of the person are bent only to a small extent. However, as soon as the operating de¬ vice is put into operation, the seat member is pivoted upwardly on pivoting upwardly of the seat frame. In the preferred case, wherein the operating device is devised so as to mainrain the seat member generally horisontal OMPI in its upwardly pivoted position, it is obtained that a person sitting in the chair may manoeuvre himself ver¬ tically as desired. DISCLOSURE OF THE DRAWINGS With reference to the appended drawings, a more specific disclosure of an embodiment of the invention .will follow hereinafter. In the drawings: fig 1 is a diagrammatical side view of the chair; fig 2 is a view similar to fig 1 but illustrating the chair in another position; fig 3 is a partially cut perspective view of the chair in an additional position; and fig 4 is a side view of the chair in a reclined position. DETAILED DISCLOSURE OF A FREFERRED EMBODIMENT The chair in figs 1-4 comprises a seat device 1 pivot- ably supported on a frame 2 of the chair about a ge¬ nerally horisontal axis 3. A back rest 4 is pivotably supported relative to seat device 1 about a second axis 5 generally parallel to the first mentioned axis 3. Power means 6 is adapted to actuate the seat device and back rest 4 to pivot the seat device 1 about axis 3 in¬ to a forwardly inclined position. The means 6 is in the embodiment acting between base 2 and seat device 1. The back rest 4 is connected to or capable of being held to the base 2 by means of an operating element 7, which is adapted, on forward pivoting of seat device 1 and back rest 4 from the initial position according to fig 1 , to subject the back resz 4 to a tractive force causing an increase of the angle cO between back rest 4 and the seat surface 8 of the seating device. The operating element 7 could consist of a single trans¬ mission link or rod being invariable as to its length and pivotably connected to base 2 and an attachment 11 connected to the back rest by hinges 9 and 10. How- ever, it is for reasons which will be explained herein¬ after preferred that operating element 7 has an adjust¬ able length. According to a preferred embodiment, this can be obtained in that the operating element consists of a piston cylinder mechanism, the length of which is adjustable and securable by shutting off fluid supply and drainage. The same may preferably also apply in connection with power means 6. The base 2 is preferably provided with wheels to enable movement of an invalid sitting in the chair. The base may also be motor driven and steerable. It is preferred that the pressure fluid ' supply to the cylinders 6 and 7 is obtained -by a pump (not illustrated) mounted on the base, said pump being driven by an electric motor receiving current from an accumulator which is provided " ' on the base and is rechargable. Back rest 4 is pivotable relative to seat device 1 about axis 5 from the position according to fig 1 to the posi¬ tion according to fig 4. To enable such a pivotal movement of the back rest, the distance between the hinges 9 and 10 of cylinder 7 must be decreased and this is obtained in that the piston rod of he cylinder is pressed into the same, after having opened the fluid outlet from the cylinder, by influence of the force applied on the back rest by the person sitting in the chair. The back rest 4 can be locked in the desired position of pivoting relative to seat device 1 by shutting off the fluid outlet of the cylinder 7 once again. If the back rest 4 is to be pivoted to the posi¬ tion according to fig 1 , the cylinder 7 is supplied with pressure fluid from the pump so that the pivoting is automatic. The chair is provided with a leg support 12 pivotably supported relative to base 2. The axis of pivoting of the leg support coincides with the axis of pivoting 3 of the seat device 1. The leg support 12 is connected to back rest 4 by two spaced, generally parallel connec¬ ting members 13 so that the pivotable movements of the back rest and leg support occur in synchronism in such a manner that rearward pivoting of the back rest is associated to upward pivoting of the leg support 12 and vice versa. This is clear from a comparison of figs 1 and 4 where the leg supporting surface 14 of support 12 is generally horisontal. The connecting members 13 are at 15 hingedly connected to leg support 12 and at 10 to back rest 4. Hinge axis 10 is common to members 13 and operating element 7. The leg support 12 is provided with a foot supporting surface 16 extending perpendicularly to the leg suppor¬ ting surface 14. The surface 16 may be formed by two spaced plates as indicated in fig 3. The plates may have rubber blocks 67 for smooth contact to the floor. The seat device 1 comprises two components pivotable relative to each other about a third axis 17 generally parallel to axes 3 and 5, namely a seat frame 18 suppor¬ ted on the base about axis 3 and a member 19 forming seat surface 8, said seat member being, on forward pivo¬ ting of seat frame 18 into a forwardly inclined posi¬ tion (fig 3), movable, by rotation about axis 17, into a position, in which a forward portion 20 of seat member 19 is raised relative to at least a forward portion of seat frame 18. It is preferred that seat frame 18 is supported on the base in the vicinity of its forward end portion while seat member 19 is supported on the seat frame in the vicinity of the rear end portion of seat member 19. It is also preferred that the support axis 17 between seat member 19 and seat frame 18 is located more near to the rear end portion thereof than the forward end por¬ tion thereof. On seat frame 18, there is behind seat member 19 provi¬ ded a fixed component 21 forming a seating surface. The components and surfaces 4, 21, 8 and 14 respectively are adapted to be provided with suitable comfortable covering. An operating device 22 acts between base 2 and seat mem¬ ber 19 to attain pivoting of the seat member relative to seat frame 18 in dependence upon pivotable movement of the seat frame relative to base 2. This operating device comprises (see fig 1) a connecting link 23, which at 24 is hingedly connected to base 2 and at 25 to an addi¬ tional link 26, which between its ends is hingedly con¬ nected (at 27) to seat frame 18. The link portion on one side . of hinge 27 is at one end hingedly connected to link 23 while the link portion on the opposite side of the hinge 27 at its end carries a roller 28 for app¬ lication against the lower side of seat member 19. A control device 28 is adapted to put the operating device 22 out of operation to thereby avoid pivotable movement between seat member 19 a seat frame 18 at pivo- ting thereof relative to the base. Control device 28 is in practice designed so that it in a first position of adjustment (adjustment is carried out by means of handle 29) locks connecting link 23, which has a vari¬ able length, so that its length no more can be changed. In a second position of adjustment (see fig 2) the control device 28 releases connecting link 23 so that its length may be varied. Connecting link 23 may be constructed with two telescopically associated parts 29 and 30. The control device 28 is arranged on the female " BUR£4 O PI telescopical part 30 and may comprise a locking pin 31 which may interlock parts 29 and 30 and thereby secure link 23 from variation of its length in that pin 31 may protrude through an opening in part 30 and enter into a recess at the end of part 29 facing away from hinge 25. As appears from fig 3, components 23, 26 and 28 may suitably be doubled and arranged at the sides of the chair while the control device comprises a shaft 33 extending between sleeves 32 on link parts 30, said shafts enabling simultaneous locking and releasing respectively of the variability of the length of links 23. From fig 3 , it appears that the chair comprises two arm rests 34 each including two hingedly interconnected parts 35, 36, one of which is hingedly connected to back rest 4 at 37 while the other 36 is hingedly con- nected to seat member 19 at a hinge 38. The pivot shafts constituting the hinges 5, 37, 39 and 38 form, as viewed from one side of the chair, the corners of a quadrangle, e.g. a four sided parallelogram. This en¬ ables the advantageous effect that the arm rests, when they are not needed, are located fairly low with respect to seat surface 8 (see fig 4) while the arm rests are located at a high point (see figs 1 and 3) when arm rests are really required. A person, e.g. an invalid, may use the chair as follows. It is assumed that the chair is in the position accor¬ ding to fig 1. If the person would like to rise, he makes certain that control device 28 is in such a posi¬ tion that the parts 29 and 30 of links 23 may move free¬ ly relative to each other. Thereafter, he actuates an operating member (not illustrated) initiating fluid sup¬ ply to cylinder 6. Seat frame 18 and seat member 19 will pivot as a unit to the position according to fig 2 and simultaneously, the element 7, which is locked against variation of length, will by traction on the attachment 11 cause pivoting of the back rest relative to the seat frame about axis 5 in the direction of arrow 40. When the chair has assumed the final position according to fig 2 with great inclination of seat frame 18 and the back rest generally vertical, it is very easy to get out of the chair in that the person has been brought to standing or almost standing position. In a reverse manner, it is very easy to sit down in the chair. The weight of the person will cause the cylinder 6 to be slowly pressed together during fluid drainage there¬ from. A person sitting on the chair in the position according to fig 1 may also adjust control device 28 so that parts 29, 30 of the links are locked together-. Pressure fluid supply to cylinder 6 will now cause, during forward pivoting of seating frame 18 about axis 3, the links 23 to exert a tensile force on links 26 so that these are pivoted clock wise about hinges 27 and with their rollers 28 pivot seat member 19 about axis 17 to the position according to fig 3. In that position, seat surface 8 is at a considerably higher level than in fig 1 and this ensures that a person sitting in the chair gets a considerably increased range upwardly. The chair is still comfortable to sit in since seat surface 8 is generally horisontal and angle θ between said surface and back rest 4 is generally equal to corresponding angle in fig 1. As appears from fig 4, back rest 4 and leg support 12 may be pivoted into and secured in different positions by varying the length of the element 7. A particular advantage of the invention is that leg sup¬ port 12, seat device 1 and back rest 4, which in the position according to fig 4 form a generally planar lying surface, by means of extension of cylinder 6 may be moved from that position into a generally vertical OMPΓ position, which generally corresponds to fig 2 with the difference that the seat device possibly may be even more inclined, i.e. almost vertical. During this upward pivoting of components 12, 1 and 4, without changing the angles therebetween according to fig 4 (the back rest is pivoted rearwardly to a maximum extent), cylinder 7 is freely extendable. A person lying in the chair according to fig 4 may in that way be brought into a vertical position (standing on the standing surface of the leg support). In a reverse manner, a person may stand on the surface 16 and re¬ cline so that the chair from this vertical position pivots into the position according to fig 4, where¬ after the back rest and leg support . by expansion of cylinder 7 may be pivoted into the position according to fig 1. POSSIBLE MODIFICATIONS Instead of power means 6 causing a compulsory pivoting upwardly of seat frame 18, it is conceivable to use power means in the form of a resilient device, which upon pivoting downwardly of seat frame 18 under the in¬ fluence of the weight of a user may accumulate energy which can be used to simplify the person's rising .from the chair by applying a forwardly pivoting force on seat frame 18.

Claims: Claims 1. A chair comprising a seat device (1) pivotably suppor¬ ted on a base (2) of the chair about a generally horizon¬ tal axis (3), a back rest (4) pivotably supported rela- tive to the seat device about a second axis (5) generally parallel to the firstmentioned axis, power means (6) adapted to actuate the seat device and back rest to pivot the seat device to a forwardly inclined position (fig 2), said seat device comprising at least two compo- nents (18,19) pivotable relative to each other about a third axis (17) generally parallel to the first axis(3), namely a seat frame (18) supported on the base about the first axis (3) and a member (19) forming a seat surface (8), said seat member being,on forward pivoting of the seat frame into a forwardly inclined position (fig 3), movable, by rotation about the third axis (17), into a position, in which a forward portion (20) of the seat member is raised relative to at least a forward portion of the seat frame, an operating element (7 ), by means of which the back rest is connected to or capable of being held to the base, said operating element being adapted, on forward pivoting of the seat device (1) and back rest (4) from an initial position (fig 1), to subject the back rest to a force tending to increase the angle (oC) between the back rest and seat frame, and an operating device (22) acting between the base and seat member (19) to attain pivoting of the seat member relative to the seat frame (18) in dependence upon pi¬ votal movement of the seat frame relative to the base, c h a r a c t e r i z e d in that a control device (28) is adapted, upon actuation, to put the operating device (22) out of operation and thereby avoid pivotal movement between the seat member and seat frame when the latter is pivoted relative to the base. 2. A chair according to claim 1, c h a r a c t e r i z e d in that the operating device comprises a connecting link (23) connected to the base and to a second link (26), which is adapted to pivot the seat member relative to the seat frame upon actuation via the connecting link, that the length of the connecting link is variable and that the control device (28) comprises a locking member (31), which in one position locks the connecting link in a certain length adjustment (fig 3) and in a second po- sition allows variation of the length thereof. 3. A chair according to claim 1 or 2, c h a r a c t e ¬ r i z e d in that the operating device (22) is adapted to locate the seat member in a generally horisontal po¬ sition when the seat member is pivoted upwardly rela- tive to the seat frame and the seat frame is pivoted up¬ wardly relative to the base. 4. A chair according to any of claims 1-3, c h a r a c- ■ -t e- r. i z e d in that the back rest (4) is pivotable re¬ lative to the seat device when the latter is in a gene- rally horisontal sitting position (figs 1 and 4) and lockable in selected pivotal positions and that a leg support (12, 12') pivotably supported relative to the base (2) is connected to the back rest via a connecting member (13) so that pivotal movements of the back rest and leg support occur in synchronism in that pivoting rearwardly of the back rest is associated to pivoting upwardly of the leg support and vice versa. 5. A chair according to any preceding claim, c h a r a c t e r i z e d in that an arm rest (34) comprises two hingedly interconnected parts, one (35) of which is hingedly connected to the back rest (4) whereas the other (36) is hingedly connected to the seat member (19). O PI

Inventors: BERGENWALL HENNING
Applicants: BERGENWALL HENNING
Application year: 1982
Main classification: A47C15
IPC codes: A47C17, A61G5