A DEVICE IN CHAIRS WITH BACKREST

Abstract: The invention relates to a device in chairs with a backrest, preferably a work chair, having at least one support member (7, 8) carried by a stiff backrest rail (4). In accordance with the invention the support rail has a plate-like configuration including essentially parallel side egdes (4a), and the support member (7, 8) is carried by a stiff body having gripping elements arranged to grippingly engage and bear against the backrest rail side edges, said gripping elements formed with a hand grip (17) to be manually actuated for the purpose of adjusting the vertical positions of the support member relative to the seat (2) of the chair.

Description: A DEVICE IN CHAIRS WITH BACKREST The present invention relates to a device in chairs with a backrest, preferably a work chair, having at least one support member carried on a stiff backrest rail. The main purpose of the invention is to provide a structure which is simple to manufacture and handle and which allows the support cushion in question to be easily adjusted and replaced. This purpose is achieved in a device in accordance with the invention which is essentially characterised in that the backrest rail has a platelike extension includ¬ ing essentially parallel side edges, and in that the support member is carried by a stiff body having gripping elements arranged to grippingly engage and bear against the back-rail side edges, said gripping elements formed with a hand grip to be manually actuated for the purpose of adjusting the vertical positions of the support member relative to the seat of the chair. Further characteristics of the invention will appear from the appended claims. One embodiment of the invention will be described in closer detail in the following with reference to accompanying drawings, wherein: Fig. 1 is a sche atical view of a work chair equipped with the device in accordance with the invention; Fig. 2 is a sectional view taken on line II-II of Fig. 1 through the backrest part of the chair in a position thereof in which it is clamped to the backrest rail, e.g. the operative position of the back curve support cushion intended for the curve of the back; Fig. 3 is a corresponding sectional view on which the cushion supporting the back curve support cushion is released for adjustment or removal; and Fig. 4 is an explosive view of the back curve support cushion, as seen from the rear when the cushion is removed from the backrest rail. The chair illustrated in Fig. 1 comprises a support- ing base 1, a seat 2 and a backrest 3. The configuration of the base and the seat is irrelevant to the invention and possible to vary in many ways, for which reason they are marked in the drawing Figures only in dash-and-dot lines. In accordance with the shown embodiment the back- rest comprises a backrest rail 4 which, as illustrated in Figs 2 and 3, is constructed from a stiff, somewhat resilient curved board 5 forming the rear of the backrest. At its front, the board 5 is covered by a suit¬ able padding 6. Numeral reference 7 designates a first support member and numeral reference 8 designates a second support member, said members being secured to the front face of the backrest rail 4, the support member 7 serving as back curve support and the support member 8 to support the neck. The support member 7 is formed from a stiff body 9 carrying a cushion-forming padding 10 at its front. The body 9 and the padding 10 extend somewhat beyond the side edges 4a of the backrest rail 4, and said edges are gripped by gripping elements 11 which may be moved in the direction of arrow 13 against the action of springs 12, from the side edges 4a of the backrest rail to the position illustrated in Fig. 3, in which position the grip about the backrest rail edges has ceased, then allowing the back-supporting cushion 7 to be moved vertically and even to be removed from the backrest rail, as could be required, for instance in connection with cleaning or exchange of the cushion. As most clearly apparent from Fig. 4 rails 14 are secured to the rear face of the body 9 and engage in undercut recesses 15 formed in the gripping elements 11. The rails 14 may be formed e.g. by bent sheet metal fittings or a moulded plastic component. The rail illustrated in Fig. 4 is essentially of U-shaped configuration having leg end portions 14a which are bent outwardly in opposite directions and in turn engage in the undercut part of the associated recess 15. Intermediate the side flanges of the rail 14 extends a stay 14b forming an end attachment for tension springs 16, the opposite ends of which are attached in the depressed area in the gripping element 11 that houses the rail 14. In accordance with the shown embodiment two tension springs are provided but obviously a different number of tension springs may be used, should this be deemed suitable. Obviously also compression springs may be used to force the gripping element in the direction towards the backrest rail side edge 4a. On its external face the gripping element which is provided with a depression 17 forming a hand grip. Externally of the backrest rail the body 9 is bent at a slight angle in the forwards direction, imparting to the sliding movement of the grip element a correspondingly angled direction. Owing to this arrangement the gripping element may easily be moved to its release position by a person sitting on the chair and gripping the hand grip recess 17 of the gripping element. The member 7 designed to support the curve of the back has been described in the aforegoing but the same description is valid also in respect to the support member forming the neck support. In accordance with the embodiment illustrated the support member has two moving gripping elements but it is likewise possible to design one of the gripping members as an integral part of the body 9. Preferably, the backrest is attached to the seat 2 of the chair by means of a fitting arranged in such a manner that the entire backrest rail with the support members mounted thereon may be raised and lowered simultaneously, but owing to the individual adjustability of the support members individual adjustments to the person sitting in the chair may be effected in some simple operations, also in the case it is not possible to raise or lower the entire backrest. The invention is not limited to the configuration of the backrest rail shown, it being possible to vary its curvature, padding and width within wide limits without departing from the inventive idea. Furthermore, the padding of the backrest may be varied in order to provide support to the back also intermediate the raisable and lowerable support members 7, 8. By moving the gripping elements 11 outwardly, away from the backrest rail side edges 4a it is easy to slide the support members off the backrest rail by pulling them forwards, but obviously it is also possible to remove the support members from the backrest rail by pushing them upwards. In accordance with the embodiment illustrated the extension of the grip engagement of the gripping elements around the edge portion 4a of the backrest rail is smaller than the maximum possible movement of displacement of the gripping elements but it falls within the scope of the inventive idea to make the engagement larger, an arrangement which would require the support member to be removed from the upper end of the backrest rail. Because it is possible to remove the support members from the backrest rail in a simple manner these members are easily exchangeable for members of different con¬ figuration, colour, or otherwise adjusted to the pre¬ vailing needs or wishes of the person to use the chair. Because in accordance with the embodiment illustrated according to which the support members extend beyond the narrower backrest rail a backrest is provided allowing the user a large freedom of movement without obstacles to swinging movements of arms, shoulders, and other parts of the body in relation to the backrest while at the same time the support members may be configured to closely support sensitive parts of the body. Obviously, it is also within the scope of protection of the invention to use only one movable and attachable support member, either the latter is to serve to support curve of the back or the neck. In such cases, the padding of the backrest rail preferably is configured to form a stationary support for the user' s neck or curved portion of the back. Obviously, also more than two movable support members are possible, should this be desired. Preferably, the backrest rail side edges 4a are essentially parallel along at least the major part of the height of the backrest rail, which affords a large free- dom of choice of the positions of the supports members vertically. In accordance with the shown embodiment the backrest rail is a board or plate, but obviously other means may be used as the stiff part of the backrest rail, such as one or several rods supporting the padding of the backrest. To obviate the padding of the backrest rail altogether does not either involve a departure from the inventive idea, in which case the only padding of the backrest would be that of the support members. Preferably, the backrest rail is somewhat resilient but it would be within the scope of protection of the invention to form the rail without such springiness. In accordance with the shown embodiment the gripping elements 11 have a configuration adapted to that of the rear of the backrest rail, which enhances the aesthetical impression of the chair. Obviously, it is quite possible to modify the invention further as to details without departure from the basic idea.

Claims: CLAIMS 1. A device in chairs with a backrest, preferably work chairs, having at least one support member (7, 8), carried by a stiff backrest rail (4), c h a r a c ¬ t e r i s e d in that the back rail has a plate-like extensions including essentially parallel side edges (4a), and in that the support member (7, 8) is carried by a stiff body (9) having gripping elements (11) arranged to grippingly engage and bear against the backrest rail side edges, said gripping elements formed with a hand grip (17) to be manually actuated for the purpose of adjusting the vertical positions of the support member relative to the seat (2) of the chair. 2. A device as claimed in claim 1, c h a r a c ¬ t e r i s e d in that the support member (7, 8) is a padded cushion (10) which is secured to a stiff body (9) . 3. A device as claimed in claim 1 or 2, c h a r ¬ a c t e r i s e d in that the gripping elements (11) are formed by projectings on the rear face of the support member (7, 8), said projections having facing grip edges, and least one of said projections being movable along the plane of the support member between a clamped position (Fig. 2) wherein its clamping face is pressed against a side edge (4a) of the backrest rail, and a released position (Fig. 3), wherein the support member is verti- cally displaceable along the backrest rail (4) . 4. A device as claimed in claim 3, c h a r a c ¬ t e r i s e d in that the gripping elements (11) have a liberty of movement dimensioned to allow the support member to be removed and to be mounted in the rearwards and forwards directions, respectively, in relation to the backrest rail (4). 5. A device as claimed in claim 3, c h a r a c ¬ t e r i s e d in that the movable projection is spring- biased towards its clamping position. 6. A device as claimed in claim 3, c h a r a c ¬ t e r i s e d in that the movable projection (11) is guided for displacement towards the rest (9, 10) of the support member along a forwardly angled plane as seen in a direction outwards from the backrest rail. 7. A device as claimed in any one of the preceding claims, c h a r a c t e r i s e d in that the gripping elements (11) are spring-biased in a direction towards their gripping position. 8. A device as claimed in any one of the preceding claims, c h a r a c t e r i s e d in that it comprises a lower member (7) serving to support the curve of the back as well as an upper member (8) serving to support the neck. 9. A device as claimed in claim 3, c h a r a c ¬ t e r i s e d in that the gripping elements (11) are formed with an interior recess (15) housing spring and guide means (16, 14) in such a manner that said means are accommodated interiourly of the outer profile of the gripping elements. 10. A device as claimed in any one of preceding claims, c h a r a c t e r i s e d in that said gripping elements (11) are sliding blocks the configuration of which softly merges into the outer profile of the support member, forming a unit that is shape-adapted to said support member.

Inventors: STAVRELL BENGT OLOF, STAVRELL, BENGT, OLOF
Applicants: STAVRELL BENGT OLOF, SUN FLEX AB, STAVRELL, BENGT, OLOF, SUN-FLEX AB
Application year: 1996
Main classification: A47C7
IPC codes: A47C7