Abstract:
A chair with at least one foot, a support profile, on which a seat and optionally a backrest is arranged, whereby the seat is continuously adjustable for height on the support profile. The seat is thus securely locked at a desired height, by means of a height lock.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The invention relates to a chair having at least one foot and a support profile, on which a seat and, if appropriate, a backrest is arranged, it being possible for the seat to be adjusted in a stepless manner in height on the support profile and to be fixed in a secured manner at a desired height by a height-securing means, a connecting element being provided between the support profile and seat, and the seat being mounted in an articulated manner in relation to the connecting element.  
         [0002]     Chairs are available in a wide variety of different shapes and forms. The present invention is concerned specifically with a chair for which it is possible to set the seat height and/or seat depth. The invention is also concerned with a chair which is collapsible.  
         [0003]     U.S. Pat. No. 4,148,523, for example, discloses a chair of which the seat can be adjusted in height along a support profile. For adjustment purposes, the seat is raised, a connecting element is displaced along the support profile and the seat is then lowered again, in which case it subjects the support profile to a clamping action.  
         [0004]     This chair has the disadvantage that if, for example, the seat is raised accidentally, the height is easily adjusted of its own accord. The clamping action of the seat in relation to the support profile depends essentially on the pressure to which the seat is subjected.  
         [0005]     In order to avoid accidental displacement of the seat height, height-securing means are provided on the seat. It is likewise the case that such height-securing means are known and commonly used in a wide variety of different shapes and forms.  
         [0006]     For example, EP 1 020 138 A1 describes a seat in which height and depth adjustment takes place by means of a toothed engagement strip, which runs on a chair framework, and a retaining device, which is assigned to the seat and on which a gearwheel, which meshes with the toothed engagement strip, is seated and drive means, which can be driven in rotation by the gearwheel, are arranged.  
         [0007]     In order for it to be possible, then, to fix the seat at a certain height, the retaining device is assigned a clamping device, which clamps the retaining device firmly on the chair framework.  
         [0008]     A further height-securing means is described in DE 195 19 739 A1. Here, a seat is connected to a support element via a screw and via a supporting arm. The supporting arm engages in a slot in the support element and, following release of a fastening means, can be displaced vertically in order then to be fixed again by means of the fastening means.  
         [0009]     WO 99/00038 describes a further chair, which likewise has a height-adjustable and depth-adjustable seat panel which is assigned a support element. A height-securing means is produced here by the interengagement of noses on the support element with grooves in guide rails in side elements of the chair and of the support element itself with grooves of a gearwheel-like element on the rear side of the chair, clamping elements ensuring that the seat is fixed.  
         [0010]     U.S. Pat. No. 6,017,089 discloses a chair of the above-mentioned type, the seat of which has a frame which is assigned a clamping device. This clamping device comprises frictional elements, which are assigned to the frame of the seat via pins. When the seat frame is rotated in the direction of a horizontal position, the frictional elements come into frictional contact between the support profiles of the chair, as a result of which a clamping action is produced. This clamping action is secured by a push-in pin.  
         [0011]     The disadvantage with the above-described height-securing means, however, is that they are mostly connected directly to the seat or else to the support profile of the seat. This gives rise to a complicated construction for the height-adjusting means and thus also for the height-securing means, which results, in turn, in more difficult handling.  
         [0012]     Furthermore, in the case of some of the above-mentioned height-securing means, the action of securing the seat at the desired height is insufficient since they rely merely on a clamping action between the seat and support profile. Furthermore, the height-securing means do not operate automatically.  
         [0013]     Added to this is the fact that, in particular if use is made of, for example, screw-like elements, the screw-like element may jam in the support profile or the like, which may result, inter alia, in possible injury to the user.  
         [0014]     The object of the present invention is thus to develop a chair of the above-mentioned type which is provided with a height-securing means which is highly variable in terms both of its settings and its handling, is easy to operate and, nevertheless, provides a sufficient securing action against the seat being adjusted out of its desired height.  
       SUMMARY OF THE INVENTION  
       [0015]     The foregoing object is achieved in that the seat is mounted in an articulated manner in the vicinity of its top side and, in the use position, presses onto the support profile by way of a rear covering, the height-securing means having an adjusting catch on the connecting element, an edge of the seat engaging behind it in this use position.  
         [0016]     By means of the arrangement, a covering which is present on the seat support is pressed against the support profile, as a result of which the position of the seat support is secured.  
         [0017]     By virtue of the height-securing means being fitted on a connecting element, its handling is simplified to a considerable extent. All that is required is for the seat to be moved to its desired height. It is then possible for the height-securing means on the connecting element on the support profile to be moved into the corresponding position beneath the seat and fixed.  
         [0018]     In another exemplary embodiment, the height-securing means has at least one clamping element which is guided in a guide slot such that, at soon as the seat or seat support has reached its desired height, the clamping element exerts a clamping action preferably in conjunction with the support profile, which avoids the situation where the seat is moved out of position without the clamping element being released.  
         [0019]     In a further exemplary embodiment, it is even conceivable to provide two clamping elements, the second clamping element preventing the seat from being raised.  
         [0020]     A further feature of the invention, for which independent protection is also sought, concerns the support profile being fixed in an articulated manner on at least one foot.  
         [0021]     This means that a collapsible chair is produced.  
         [0022]     For this purpose, it is possible to fix, for example, on the foot a bearing link plate which is connected to the support profile in an articulated manner via an articulation pin. At the same time, the bearing link plate also forms a stop for the support profile as soon as the latter is in the use position.  
         [0023]     The use position is secured by a latching catch, which engages in the support profile by way of a latching nose. This takes place under the pressure of a spring, with the result that it is only when this pressure is eliminated that the latching catch is released and the support profile is thus freed.  
         [0024]     Yet a further idea of the present invention, for which independent protection is likewise sought, confirms the adjustability of the seat depth. It is conceivable, in principle, for the seat depth to be of adjustable configuration. This can be achieved, in one instance, in that an appropriate, for example textile, seat surface is rolled up and can be unrolled as desired from, for example, a roller.  
         [0025]     The seat depth is preferably increased and decreased under the action of a telescopic element. This could be, for example, a lamellar pull-out mechanism, at least one toggle lever or a scissors element.  
         [0026]     In another exemplary embodiment, it is conceivable to form the seat surface from a plurality of parts, in which case the parts are drawn apart from one another, and supplemented by new parts, as desired. It is also the case here that the present invention should not be subject to limitations.  
         [0027]     A particular idea of the invention, for which separate protection is likewise also sought, concerns the arrangement of an additional backrest, the adjustment of which can likewise change the seat depth.  
         [0028]     Of course, it is conceivable for all the independent features also to be realized in one chair, for which protection is likewise sought. This results in the production of a chair which is highly variable in respect of its settings. Furthermore, it can easily be collapsed and transported. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0029]     Further advantages, features and details of the invention can be gathered from the following description of preferred exemplary embodiments, and with reference to the drawing, in which:  
         [0030]      FIG. 1  shows a perspective view of a chair according to the invention;  
         [0031]      FIG. 2  shows a side view of a detail of the chair according to  FIG. 1  in the region of the connection between the support profile and foot;  
         [0032]      FIG. 3  shows a detail of the chair corresponding to  FIG. 2 , but in another use position;  
         [0033]      FIG. 4  shows a detail of the chair according to  FIG. 1  in the region of the connection between a seat and a support profile;  
         [0034]      FIG. 5  shows the detail according to  FIG. 4  in another use position;  
         [0035]      FIG. 6  shows a further exemplary embodiment of a detail of the chair according to  FIG. 1  similar to  FIGS. 4 and 5 , in different use positions;  
         [0036]      FIG. 7  shows a detail of a further exemplary embodiment of the chair according to  FIG. 1  similar to  FIG. 6 ;  
         [0037]      FIGS. 8-13  show perspective views of exemplary embodiments of seat surfaces with a changeable depth; and  
         [0038]      FIG. 14  shows perspective views of possible ways of achieving backrest adjustment. 
     
    
     DETAILED DESCRIPTION  
       [0039]     According to  FIG. 1 , a chair P according to the invention has two feet  1 . 1 . and  1 . 2 , which are each connected to a support profile  2 . 1  and  2 . 2 . The support profiles  2 . 1  and  2 . 2  accommodate a backrest  3  between them.  
         [0040]     A seat  5  is connected to the support profiles  2 . 1  and  2 . 2  via a respective connecting element  4 . 1 ,  4 . 2 . This connection takes place, if appropriate, via corresponding seat supports  6 .  
         [0041]     It can be seen in  FIGS. 2 and 3  that a support profile  2  is connected to a foot  1  via an articulated connection  7 . In this case, the articulated connection  7  preferably has two bearing link plates  8  arranged one behind the other, the bearing link plates  8  being connected to the support profile  2  via an articulation pin  9 . The support profile  2  can rotate about the articulation pin  9 .  
         [0042]     The rotary movement of the support profile  2  in relation to the bearing link plate  8 , however, is limited by an angled portion  10 , which forms a stop for the support profile  2 .  
         [0043]     Provided between the two bearing link plates  8  is a latching catch  11  which, in the use position according to  FIG. 2 , engages in the support profile  2  by way of a latching nose  12  and fixes this support profile in the use position.  
         [0044]     The latching nose  12  can be disengaged from the support profile  2  by a lever  13  being subjected to pressure, the latching catch  11  thus being moved out of the latching position counter to the pressure of a spring  14 , as is shown in  FIG. 3 . In this case, the latching catch  11  rotates about a pin  15 .  
         [0045]     For latching-in purposes, the support profile  2  is pivoted about the articulation pin  9 , in which case a control edge  16  slides onto the latching catch  11  and passes beyond the latching nose  12  until the latching nose moves into the support profile  2  under the pressure of the spring  14 .  
         [0046]     According to  FIGS. 4-7 , it is intended for it to be possible for the seat  5  or its seat supports  6  to be displaced along the support profile  2  and fixed at a desired height. For this purpose, the connecting element  4  is assigned a height-securing means  17 . This height-securing means  17  has an adjusting catch  18 , which is mounted in the connecting element  4  such that it can be pivoted about a pivot pin  19 .  
         [0047]     The adjusting catch  18  has a latching edge  20 , which interacts with an edge  21  on the seat support  6 .  
         [0048]     The seat support  6  is arranged on the connecting element  4  such that it can be pivoted about a further pivot pin  22 . The pivot pin  22  here is arranged such that the surface area of a covering  23  assigned to the seat support  6  butts against the support profile  2  in the seating position of the seat support  6  ( FIG. 5 ), in which case, at the same time, the edge  21  has passed beyond the latching edge  20  of the adjusting catch  18  and the adjusting catch  18  has engaged over the edge  21  under the pressure of a spring  24 . As a result, on the one hand, the covering  23  is pressed onto the surface of the support profile  2  and, on the other hand, it is retained in this position by the adjusting catch  18 , with the result that displacement of the connecting element  4  along the support profile  2  is only possible once the adjusting catch  18  has been released.  
         [0049]      FIGS. 6   a  to  6   c  shows a further exemplary embodiment of a height-securing means  17 . 1 . This height-securing means  17 . 1  has a pivot lever  25  which is coupled to the connecting element  4  such that it can be rotated about a swivel pin  26 . This pivot lever  25  can be used to move a clamping roller  27  in a guide slot  28 . The guide slot  28  is of curved design, and the support profile  2  projects some way into its inside width.  
         [0050]     With the clamping roller  27  released according to  FIG. 6   a , the connecting element  4  can be moved along the support profile  2 . If the desired height for the seat has been reached, the pivot lever  25  is rotated about the swivel pin  26 , with the result that the clamping roller  27  passes into the region of the support profile  2 . This achieves a clamping action between the guide slot  28 , clamping roller  27  and support profile  2 , as is indicated in  FIG. 6   b.    
         [0051]     If the seat support  6  is then pivoted about its pivot pin  22 , as is shown in  FIG. 6   c , then the covering  23  comes into contact with the support profile  2 , in which case, if desired, the covering  2  can also be positioned in relation to the surface of the support profile  2  such that the connecting element  4  is offset slightly in the downward direction. Consequently, the clamping roller  27  is drawn yet further into the clamping region between the guide slot  28  and surface of the support profile  2 , with the result that secured fixing takes place.  
         [0052]     According to the exemplary embodiment of  FIG. 7 , two pivot levers  25  and  25 . 1  are to be provided on the connecting element  4 . Both are assigned a guide slot  28  and  28 . 1  and a clamping roller  27  and  27 . 1 . The clamping roller  27 . 1  here has the task of preventing displacement of the connecting element  4  in the opposite direction, i.e. in the upward direction on the support profile  2 . This exemplary embodiment thus avoids displacement of the connecting element both in the downward direction and in the upward direction.  
         [0053]     A further part of the present invention is concerned with the possibility of seat-depth adjustment.  FIGS. 8-13  indicate, schematically, possible ways in which a seat depth can be adjusted.  
         [0054]     According to  FIG. 8 , a seat surface  30  envelops a roller  31 , it being possible, for example, for the seat surface  30  to consist of textile material. If the seat surface  30  is pulled, for example counter to the force of a tension element, then a part of the surface which has hitherto been located in the seat is pulled out and can serve as a seat surface.  
         [0055]     According to  FIG. 9 , the seat surface  30  could also be wound up onto a roller  31 . 1  at one end, in which case it would be possible for this roller to be subjected to prestressing, as a result of which the seat surface  30  is held taut.  
         [0056]     According to  FIG. 10 , a seat surface  30  (not shown specifically), for example according to the exemplary embodiment of  FIG. 9 , could have a lamellar pull-out mechanism  32  arranged beneath it. The lamellar pull-out mechanism  32  is configured such that individual lamellae can be displaced telescopically in relation to other lamellae.  
         [0057]     According to  FIGS. 11 and 12 , similar extension of the seat surface  30  is achieved by means of toggle levers  33  and scissors mechanisms  34 , respectively.  
         [0058]     In a straightforward exemplary embodiment of the invention according to  FIG. 13 , it is sufficient if the seat surface comprises a plurality of seat-surface elements  35 . 1  to  35 . 2  which may be connected to one another.  
         [0059]      FIG. 14 , furthermore, illustrates chairs in which a normal backrest  3  has a further backrest  36  arranged in relation to it. This additional backrest  36  can be adjusted along the seat  5 , with the result that it is possible to adapt a seat depth to an individual. This can take place, in one instance, by the backrest  36  being plugged into mounts  37  arranged at different positions. However, stepless adjustment is also conceivable, in which case an appropriate slot-like recess  38  is formed in the seat. An appropriate mechanism for adjusting the backrest  36  is not shown specifically here.