Abstract:
In order to provide an adjustment mechanism for the arm support of an armrest, which is particularly simple structurally and which also enables a particularly flat style of construction, a locking device is proposed for releasably locking the base platform and the carrier platform in different positions with respect to each other, said locking device comprising a transfer element, which is arranged between carrier platform and arm support and is connected to the base platform and which has first blocking elements for blocking the longitudinal adjustment of the arm support and second blocking elements for blocking the transverse adjustment of the arm support, and an actuating element, which is arranged between carrier platform and arm support and is provided with a control button for manual actuation and which has elements for simultaneously blocking or releasing the first and second blocking elements of the transfer element.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the priority, under 35 U.S.C. §119, of German patent application DE 10 2011 008 172.0, filed Jan. 10, 2011; the prior application is herewith incorporated by reference in its entirety. 
       BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0002]    The invention relates to an armrest, in particular to an armrest for an office chair. More specifically, the invention relates to an armrest having a preferably height-adjustable armrest column, an arm support mounted on the armrest column and having a bearing head, which serves for the bearing arrangement of the arm support on the armrest column, is attached to the armrest column and has a longitudinal and a transverse adjustment mechanism for longitudinal or transverse adjustment of the arm support. 
         [0003]    Different designs of these types of armrests are known from the prior art. In the case of these prior art armrests, to realize the longitudinal or transverse adjustment of the arm support, the bearing head, in the majority of cases, has structurally expensive adjustment mechanisms which, over and above this, also require a large installation space such that the armrests are not only comparatively expensive to produce, but are clearly built-up in part in the region of the arm support. In addition, the actuating devices required for actuating the adjustment mechanisms clearly project in part out of the armrest column or the arm support, which is frequently undesirable from a structural and/or ergonomic standpoint. 
       SUMMARY OF THE INVENTION 
       [0004]    It is accordingly an object of the invention to provide an armrest assembly which overcomes the above-mentioned disadvantages of the heretofore-known devices of this general type and which provides for an adjustment mechanism for the arm support of an armrest which is particularly simple structurally and also enables a particularly flat style of construction. 
         [0005]    With the foregoing and other objects in view there is provided, in accordance with the invention, an armrest, in particular for an office chair, comprising: 
         [0006]    an armrest column; 
         [0007]    an arm support mounted on said armrest column; and 
         [0008]    a bearing head attached to said armrest column, said bearing head supporting said arm support on said armrest column and having a longitudinal adjustment mechanism for a longitudinal adjustment of said arm support and a transverse adjustment mechanism for a transverse adjustment of said arm support; 
         [0009]    said bearing head including:
       a stationary base platform connected to said armrest column;   a movable carrier platform connected to said arm support; and   a locking device for detachably locking said base platform and said carrier platform in different positions with respect to one another;       
 
         [0013]    said locking device including:
       a transfer element disposed between said carrier platform and said arm support and connected to said base platform, said transfer element having first blocking elements for blocking the longitudinal adjustment of said arm support and second blocking elements for blocking the transverse adjustment of said arm support; and   an actuating element disposed between said carrier platform and said arm support, said actuating element having a control button for manual actuation and elements for simultaneously blocking or simultaneously releasing said first and second blocking elements of said transfer element.       
 
         [0016]    In other words, a core concept of the invention is to provide a locking device which has an actuating element, which is arranged between the carrier platform and the arm support, for simultaneously blocking or releasing all participating assemblies as well as a transfer element, which is arranged between the carrier platform and the arm support and which transfers the blocking functionality of the actuating element to the individual components. Consequently, a longitudinal and transverse adjustment can be realized in a comparatively simple manner using few components. This means that not only are the production costs reduced, error susceptibility also falls. As a result, a particularly reliable adjustment mechanism is provided which can be realized in the smallest space. 
         [0017]    As a result of the advantageous dual function of the transfer element, which, on the one hand, executes the transverse movement together with the carrier platform and serves as a guide element for the longitudinal movement of the carrier platform and, on the other hand, has blocking elements both for blocking the longitudinal adjustment and for blocking the transverse adjustment, the use of further components can be dispensed with. On account of the selected construction concept, the necessary components can be positioned with respect to each other in the final assembly state such that they fill out the space, which is there anyway, between carrier platform and arm support and, over and above this, such that they are arranged more or less fitting into each other, as a result of which an extremely low installation height is produced. 
         [0018]    Other features which are considered as characteristic for the invention are set forth in the appended claims. 
         [0019]    Although the invention is illustrated and described herein as embodied armrest, in particular for an office chair, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
         [0020]    The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0021]      FIG. 1  shows a perspective view, from above, of an exploded representation of an armrest according to the invention; 
           [0022]      FIG. 2  shows a perspective view, from below, of an exploded representation of the armrest; 
           [0023]      FIG. 3  shows a cross section taken through the armrest; 
           [0024]      FIG. 4  shows a longitudinal section taken through the armrest; 
           [0025]      FIG. 5  shows a top view of the armrest with the arm support removed, in the locking position; and 
           [0026]      FIG. 6  shows a top view of the armrest with the arm support removed, in the open position. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    Referring now to the figures of the drawing in detail, there is shown an armrest  1  that includes a height-adjustable armrest column  2 , which is preferably constructed in a telescopic manner and on the upper end of which a bearing head  3  is arranged. The bearing head  3  supports an arm support  4  and is realized for displacing the arm support  4  in relation to the armrest column  2  both in the longitudinal direction  5  and in the transverse direction  6 . The support cushioning of the arm support  4  is not shown. 
         [0028]    A non-illustrated vertical portion of the armrest column  2  is realized as a guide stand, on which the outer sleeve of the armrest column  2  is guided so as to be displaceable in the vertical direction  7 . A height-adjustment locking means is installed in the guide stand. An actuating control button  54  that is provided for the height-adjustment of the armrest  1  is arranged laterally on the armrest column  2 . A horizontal portion (not shown) that is integrally formed on the vertical portion of the armrest column  2  serves for fastening the armrest  1  to the support structure of an office chair or the like. 
         [0029]    At the upper end of the armrest column  2 , the outer sleeve flares outward in relation to the actual column part and thus forms a carrier  8  for the bearing head  3 . The bearing head  3  consists primarily of a fixed base platform  9  which is connected to the armrest column  2  and a carrier platform  11  which is connected to the arm support  4  and is movable horizontally in the transverse direction  6  and the longitudinal direction  7 . 
         [0030]    The outer sleeve is upwardly open, the opening  12  being closed by the base platform  9  of the bearing head  3  in the manner of a cover. The base platform  9  is connected to the armrest column  2  by way of a plurality of non-illustrated fixing screws. The fixing screws are guided through openings  16  formed in the base platform  9  and cooperate with screw threads which are provided in support elements  15 , which are arranged in the opening  12  of the outer sleeve extending upwards in the shape of a dome to provide additional support of the base platform  9 . 
         [0031]    The base platform  9  has two guide channels  22 , which are arranged spaced apart from each other, run transversely with respect to the longitudinal direction  21  of the arm support, essentially have a rectangular contour, run in a straight line, extend substantially over the entire width of the base platform  9  and determine the measurement of the maximum adjustment of the arm support  4  in the transverse direction  6 . 
         [0032]    The carrier platform  11  is arranged above the base platform  9 . The carrier platform  11  includes a base element  25 , which, with a circumferential support element  26  that is arranged close to the edge, forms an upwardly open housing, onto which the arm support  4  is placed. In the mounted state, the circumferential support element  26  abuts against the inside of a circumferential retaining wall  28 , which is provided on the underside  27  of the arm support  4 , and thereby ensures the arm support  4  is securely held on the carrier platform  11 . 
         [0033]    In the mounted state, the carrier platform  11  is screw-connected to the arm support  4 , the fixing screws (not shown), penetrating through corresponding openings  29  of the base element  25 , cooperating with screw threads which are arranged in the dome-shaped support elements  15  which extend vertically downward from the underside  27  of the arm support  4 . 
         [0034]    A guide channel  31 , which runs in the longitudinal direction  21  of the arm support and transversely with respect to the guide channels  22  of the base platform  9 , is provided in the base element  25  of the carrier platform  11 , said guide channel  31  extending over a substantial part of the length of the carrier platform  11 . 
         [0035]    A transfer element  13  is arranged between the carrier platform  11  and the arm support  4 . The strip-shaped base body  33  of the transfer element  13  covers the guide channel  31  in part. In the region of the guide channel  31 , the base body  33  has two lead-through openings  34  which are spaced apart from each other, the distance between the two lead-through openings  34  corresponding to the distance between the two guide channels  22  in the base platform  9 . 
         [0036]    Two non-illustrated lock screws are used to mount the carrier platform  11  on the base platform  9 . The lock screws connect the transfer element to sliding blocks  36  through the openings  34  of the base body  33 . By way of their necks  37 , the sliding blocks  36  project through the guide channel  31  in the base element  25  of the carrier platform  11 , as well as through the right-hand or left-hand guide channel  22  in the base platform  9 . In other words, the necks  37  are inserted as guide elements in the guide channels  22 ,  31 . 
         [0037]    The main bodies  38  of the sliding blocks  36  attached to the necks  37  are arranged below the base platform  9  in the interior of the outer sleeve, which is widened at the upper end of the armrest column  2 . The main bodies have transverse guide grooves  41 , which are directed towards the underside  40  of the base platform  9  and which, in the mounted state, cooperate with guide webs  39  attached on the underside of the base platform  9 , in order to ensure the carrier platform travels securely on the base platform  9 . The guide grooves  41 , in this case, run parallel to the guide channels  22 . 
         [0038]    Connected together in this manner, the arm support  4  with the carrier platform  11  can be moved within the framework of the guide channels  22 ,  31  in the longitudinal and transverse direction  5 ,  6  on the base platform  9  attached to the armrest column  2 . 
         [0039]    To provide for locking of the base platform  9  and the carrier platform  11  into different positions with respect to each other, a locking device with an actuating device is provided. The actuating device  44 , just as the transfer element, is arranged in the inside space  48  formed between the carrier platform  11  and the arm support  4 . The actuating device  44  includes an actuating element  49 , which is displaceable in the interior of the inside space  48  transversely with respect to the longitudinal direction  21  of the arm support and consequently parallel to the guide channels  22  in the base platform  9 . The actuating element  49  has two rows of teeth  52 ,  53 , which are spaced apart from each other and run parallel to the guide channel  31  in the carrier platform  11 . 
         [0040]    The actuating element  49  is guided at, on or between guide webs  68 ,  69 , which are provided extending in the transverse direction  6 , on the one hand, on the upper side  32  of the base element  25  and, on the other hand, on the underside  27  of the arm support  4 . 
         [0041]    Two compression springs  62  that are arranged transversely with respect to the longitudinal direction  21  of the arm support serve to spring-load the actuating element  49 , which, as a result, is always urged into a locking position. The compression springs  62  rest on corresponding guide pins  63  of the actuating element  49  and are supported on stop elements  64 , which serve as abutments and are provided on the underside of the arm support  4 . 
         [0042]    In the locking position, the actuating element  49  is held in a spring-loaded manner in a position in which the teeth of the rows of teeth  52 ,  53  engage in correspondingly provided teeth of blocking elements  45 ,  55  for blocking the longitudinal and transverse movement. 
         [0043]    A toothed rack  45 , which runs parallel to the base body  33  of the transfer element  13  and is arranged vertically offset with respect to the base body  33 , serves as the blocking element for blocking the longitudinal movement. A first toothed wheel  55 , which is arranged centrally on the base body  33  of the transfer element  13  and is mounted there so as to be rotatable in an opening  57 , serves as the blocking element for blocking the transverse movement. 
         [0044]    The rows of teeth  52 ,  53  lie at the identical height as the teeth of the blocking elements  45 ,  55 . If the actuating element  49  is moved in opposition to the spring force of the two compression springs  62  in the actuating direction  66 , which runs parallel to the directions of the compression springs  62 , at the same time the rows of teeth  52 ,  53  release the teeth of the blocking elements  45 ,  55 . The locking between the base platform  9  and the carrier platform  11  is then released. An actuating control button  67  serves for operating the actuating element  49 . The actuating control button  67  is released again to resume locking. The compression springs  62  press the actuating element  49  from the open position back into the locking position. At the same time, the rows of teeth  52 ,  53  engage in the nearest teeth of the blocking elements  45 ,  55 . 
         [0045]    The control button  67  for operating the actuating element  49  is connected to the actuating element  49  by means of a connecting rail  71  in such a manner that the control button  67  in the locking position projects in an only negligible manner beyond the outer edge of the arm support  4 . A corresponding recess  72  in the retaining wall  28  is provided for the connecting rail  71 . The recess  73  serves for receiving the control button  67 . 
         [0046]    If the control button  67 , which is entrained with the carrier platform  11 , is depressed, the teeth of the second row of teeth  53  of the actuating element  49  release the first toothed wheel  55 , see  FIG. 6  in which part of the actuating device has been cut away in order to make it possible to see the toothed wheel  55 . As a result of this release, it is possible to rotate the first toothed wheel  55  about its axis of rotation  58 , which extends both perpendicular to the longitudinal direction  5  and perpendicular to the transverse direction  6 . A second toothed wheel  56 , which is connected in a positive-locking manner to the first toothed wheel  55  by means of a locking element and which is arranged below the carrier platform  11 , is able to roll off on a row of teeth  59 , which is arranged on the base platform  9  in the transverse direction  6 , as a result of which a guided transverse movement of the arm support  4  takes place. The locking element is in the form of a hexagonal pin, which is integrally formed on the second toothed wheel  56  and which projects through the guide channel  31  and is secured on the first toothed wheel  55  by means of a screw  60 . The row of teeth  59  arranged on the base platform  9  is formed by one of the two longitudinal sides of a receiving opening  61 , which is arranged centrally in the base platform  9 , being provided with teeth. The receiving opening  61  is realized for receiving the second toothed wheel  56  and extends in a corresponding manner to the guide channels  22  almost over the entire width of the base platform  9 . When the control button  67  is depressed, the movement unit made up by control button  67 , carrier platform  11  and transfer element  13  is able to execute a movement in the transverse direction  6 . In this case, this is a movement which is determined by the engagement of the second toothed wheel  56  in the row of teeth  59  and is consequently guided in a defined manner. The length of the row of teeth  59 , consequently, determines the measurement of the possible transverse movement of the arm support  4 . 
         [0047]    When the control button  67  is depressed, the teeth of the first row of teeth  52  also move out of engagement with the teeth of the toothed rack  45 , which extends in the longitudinal direction  5  and is realized as part of the transfer element  13 . The toothed rack  45  is connected at the ends thereof to the base body  33  of the transfer element  13 . In addition, two ribs  46  provide the connection between transfer element  13  and toothed rack  45 . The ribs  46  provide the transverse guiding of the arm support  4 . In the mounted state, they project through the carrier platform  11 , which, for this purpose, has slot-shaped openings  47  which extend in the transverse direction  6  and intersect the guide channel  31 . The ribs  46 , which penetrate the carrier platform  11 , are received by slotted grooves  42 , which are inserted in the base platform  9  in the transverse direction  6  and are inserted into the base platform  9  on both sides of the receiving opening  61 . Consequently, with the control button  67  depressed, the movement unit, produced from control button  67  and carrier platform  11 , is able to be driven freely on both sides in the longitudinal direction  6  in relation to the transfer element  13 , which is stationary in the longitudinal direction  6 , i.e. without being guided by toothed wheel engagement or the like. 
         [0048]    If the control button  67  is released again, that is if the teeth of the two rows of teeth  52 ,  53  of the actuating element  49  once again move into engagement with the teeth of the first toothed wheel  55  or of the toothed rack  45  of the transfer element  13 , locking is resumed and the current transverse or longitudinal position of the arm support  4  in relation to the armrest column  2  is secured. 
         [0049]    It will be clear to those of skill in the pertinent art that a plurality of further implementations and embodiments of the inventive concept are available that have not been described in full detail above. Those of skill in the art will understand that the various features represented in the description, the claims and the drawings can be fundamental to the invention both individually and in arbitrary combination with each other. 
         [0050]    The following is a list of reference numerals used in the above description and may aid the reader in understanding the specification: 
         [0051]      1  Armrest 
         [0052]      2  Armrest column 
         [0053]      3  Bearing head 
         [0054]      4  Arm support 
         [0055]      5  Longitudinal direction 
         [0056]      6  Transverse direction 
         [0057]      7  Vertical direction 
         [0058]      8  Carrier 
         [0059]      9  Base platform 
         [0060]      11  Carrier platform 
         [0061]      12  Opening 
         [0062]      13  Transfer element 
         [0063]      15  Support element 
         [0064]      16  Opening 
         [0065]      21  Longitudinal direction of the armrest 
         [0066]      22  Guide channel 
         [0067]      25  Base element 
         [0068]      26  Support element 
         [0069]      27  Underside of the armrest 
         [0070]      28  Retaining wall 
         [0071]      29  Opening 
         [0072]      31  Guide channel 
         [0073]      32  Upper side of base element 
         [0074]      33  Base body 
         [0075]      34  Lead-through opening 
         [0076]      36  Sliding block 
         [0077]      37  Neck 
         [0078]      38  Main body 
         [0079]      39  Guide web 
         [0080]      40  Underside 
         [0081]      41  Guide groove 
         [0082]      42  Slotted groove 
         [0083]      44  Actuating device 
         [0084]      45  Toothed rack 
         [0085]      46  Rib 
         [0086]      47  Opening 
         [0087]      48  Inside space 
         [0088]      49  Actuating element 
         [0089]      52  First row of teeth 
         [0090]      53  Second row of teeth 
         [0091]      54  Actuating control button 
         [0092]      55  First toothed wheel 
         [0093]      56  Second toothed wheel 
         [0094]      57  Opening 
         [0095]      58  Axis of rotation 
         [0096]      59  Row of teeth 
         [0097]      60  Locking screw 
         [0098]      61  Receiving opening 
         [0099]      62  Compression spring 
         [0100]      63  Guide pin 
         [0101]      64  Abutment 
         [0102]      65  Inside 
         [0103]      66  Direction of actuation 
         [0104]      67  Actuating control button 
         [0105]      68  Guide web 
         [0106]      69  Guide web 
         [0107]      71  Connecting rail 
         [0108]      72  Recess 
         [0109]      73  Recess