Patent Publication Number: US-2017367483-A1

Title: Pivoting fitting, piece of furniture, and motor vehicle seat

Description:
The present invention relates to a pivoting fitting, especially for furniture, comprising a first pivoting lever which can be moved about an axis of rotation in relation to a second pivoting lever, wherein a blocking device is provided in order to block in a blocking position a rotational motion of the first pivoting lever in relation to the second pivoting lever in a first direction of rotation and to enable said rotational motion in an opposite second direction of rotation, and to a piece of furniture and a motor vehicle with at least one respective pivoting fitting. 
     WO 2007/088128 discloses a pivoting fitting in which a first tab is pivotably arranged in relation to a second tab. The two tabs can be latched in different angular positions via a latching mechanism, wherein latching in opposite directions is possible. There is a disadvantage in the latching of the tabs in relation to each other in that fixing of the tabs in relation to each other is only possible in predetermined angular positions. It is sometimes desirable in a fine setting of headrests or armrests to provide a finer possibility for adjustment than via the latching mechanism. Furthermore, there is frequently the problem in such pivoting fittings that a rotational motion of the tabs is only possible in a predetermined angular range, according to the construction of the piece of furniture, which limits the adjusting possibilities, and therefore increases the number of different embodiments for different angular ranges. 
     Motor vehicle seats with respective pivoting fittings are generally known. 
     It is therefore the object of the present invention to provide a pivoting fitting in which a first pivoting lever and a second pivoting lever are provided with a more flexible possibility for adjustment. 
     This object is achieved by a pivoting fitting with the features of claim  1 . 
     A blocking device is provided in accordance with the invention in order to block in a blocking position a rotational motion of the first pivoting lever relative to the second pivoting lever in a first rotational direction, wherein an infinitely variable adjustment of the blocking position is possible by a switching element which deactivates the blocking device for an adjusting process of the first pivoting lever in relation to the second pivoting lever in the first direction of rotation. As a result, the first pivoting lever can be adjusted in an infinitely variable manner relative to the second pivoting lever, so that an adjustment in all desired angles is possible. Furthermore, the first pivoting lever and the second pivoting lever can be twisted circumferentially, i.e. they can carry out an adjustment of 360° and more. Limit stops are not necessary in the fitting in accordance with the invention, but may still be advantageous in specific applications. As a result, the pivoting fitting can be used for setting backrests, headrests, armrests or other components in which an infinitely variable adjustment is desirable. Only one fitting is to required in order to cover all imaginable pivoting angles in headrests, armrests, backrests or the like. The maximum pivoting angle can be formed by add-on parts and not by the fitting itself. 
     According to a preferred embodiment of the invention, the blocking device comprises a clamping axle surrounded by a loop, which can be applied in a clamping manner around the clamping axle. A stable fixing by the blocking device can thus be achieved, which engages around the clamping axle with the loop according to the principle of the loop spring. The angle of wrap of the loop can be more than 180°, especially more than 270°, wherein also several rotations of the loop around the clamping axle are possible. 
     The switching element is preferably arranged on the loop, and in a first position a clamping fixing of the loop on the clamping axle is enabled and a tightening of the loop is blocked in the second position in order to prevent a clamping fixing of the loop on the clamping axle. The switching element thus predetermines whether the loop blocks a rotational motion of the pivoting levers or an adjusting process can be initiated when the loop is arranged in the second position. A pivoting lever can rotatably be mounted on a first arm of the loop and be in engagement with a second arm of the loop in order to fix the loop in the first direction of rotation on the clamping axle and to release the same in the second direction. The loop can be fixed in a clamping manner or released depending on the direction of the force on the pivoting lever in order to enable a rotational motion relative to the clamping axle in one direction of rotation and to prevent a rotational motion relative to the clamping axle in the opposite direction of rotation. 
     After an adjusting process, the switching element activates the blocking device in order to block a rotational motion of the first pivoting lever relative to the second pivoting lever. Such an activation can be produced for example by a movement of the first pivoting lever in relation to a second pivoting lever in the second direction of rotation, e.g. by only a few degrees so that the switching element terminates the adjusting process again. A control element can thus be provided in order to actuate the switching element. The control element can be rotatable at least in sections together with one of the two pivoting levers. For this purpose, the control element can be coupled via a coupling to one of the pivoting levers, so that no further components are necessary for actuating the blocking device. 
     For the purpose of a compact configuration, the control element can be coupled to the first pivoting lever via the coupling, whereas the second lever is rotatably mounted on the loop. The control element thus follows the movement of the first pivoting lever, while a rotational motion of the second pivoting lever depends on whether or not the blocking device is activated. 
     According to a further embodiment, the switching element can be fixed in a clamping manner in the position for deactivating the blocking device. The switching element can be formed as a pin which is pretensioned by a spring in the position in which the blocking device is effective. As a result of the clamping fixing of the pin, it can be fixed at least for one adjusting process with the pretensioned spring, wherein the spring ensures after the termination of the adjusting process that the pin is pressed directly into the blocking position when the first pivoting lever is slightly moved in relation to the second pivoting lever in the second direction of rotation. 
     The control element can comprise a guide bevel for reliable switching in order to actuate the switching element during a rotational motion. The control element can be rotated via the coupling by a pivoting lever, especially a friction coupling with a spring. 
     A projection is preferably formed on the second pivot lever, which projection engages in a receptacle on the second arm of the loop and moves the second arm of the loop in relation to the first arm during a rotational motion of the first pivoting lever in relation to the second pivoting lever in the first direction of rotation in order to fix the loop in a clamping manner around the clamping axle. In this process, the projection can be arranged adjacent to the clamping axle, thus providing advantageous lever conditions and a compact configuration. 
     The control element is preferably rotatable in a pivoting range, which is limited by two stops. The maximum adjusting range of the pivoting levers is predetermined by the stops, wherein different pivoting ranges can be realised by exchanging the control element. Handling is simpler by providing a stop, because the user perceives a defined starting and end position during the return by one or two stops. 
     For the purpose of the stable fixing of the pivoting lever on the loop it can be rotatably mounted in a slotted receptacle of the loop. As a result, transverse forces can also be transmitted from the pivoting lever to the loop. 
     A relevant advantage of the fitting in accordance with the invention is that in a piece of furniture or in a vehicle seat two substantially identical fittings can be used. This substantially reduces the amount of production work and the production costs for the fitting. In addition, the producer of the furniture or motor vehicle seat is offered the advantage that only one universally usable fitting needs to be held on stock. 
    
    
     
       The invention will be explained below in closer detail by reference to an embodiment shown in the enclosed drawings, wherein: 
         FIG. 1  shows a top view of a pivoting fitting in accordance with the invention; 
         FIG. 2  shows a perspective exploded view of the pivoting fitting of  FIG. 1 ; 
         FIG. 3  shows a top view of the loop of the pivoting fitting of  FIG. 2 ; 
         FIG. 4  shows a detailed view of the pivoting fitting of  FIG. 1  under load in the first direction of rotation; 
         FIG. 5  shows a detailed view of the pivoting fitting of  FIG. 1  under load in the second direction of rotation; 
         FIGS. 6A and 6B  show two views of the switching element in the blocking position; 
         FIGS. 7A and 7B  show two views of the switching element in the adjusting position; 
         FIGS. 8 to 11  show several views of a second embodiment of a pivoting fitting in accordance with the invention; 
         FIG. 12  shows a perspective exploded view of the pivoting fitting of  FIGS. 8 to 11 ; 
         FIG. 13  shows a sectional view of the pivoting fitting of  FIG. 12  in the blocking position; 
         FIG. 14  shows a sectional view of the pivoting fitting of  FIG. 12  in the adjusting position, and 
         FIG. 15  shows a piece of furniture with several fittings in accordance with the invention. 
     
    
    
     A pivoting fitting  1  comprises a first pivoting lever  2  and a second pivoting lever  3 , which are pivotable in relation to each other about a rotational axis. Such a pivoting fitting  1  can be used for example in furniture, for the adjustable fixing of armrests, headrests or other components. 
     The second pivoting lever  3  is fixed on a loop  4 , which surrounds a clamping axle  5 . The first pivoting lever  2  is fixed to the clamping axle  5 . The second pivoting lever  3  is rotatably mounted about a pivot  6  on the loop  4 . The pivoting range of the second pivoting lever  3  can be limited relative to the loop  4  by a pin  8  in form of a journal. The pivoting range of the second pivot lever  3  relative to the loop  4  can be a few degrees, e.g. 1° to 8°, especially 2° to 5°. A projection  7  is integrally attached to an inner end of the second pivoting lever  3 , which projection is arranged adjacent to the pivot  6 . 
       FIG. 2  shows the pivoting fitting  1  in an exploded view. The first pivoting lever  2  comprises a jagged receptacle  20  which is inserted into a similarly jagged pin  52  of the clamping axle  5 , so that the first pivoting lever  2  and the clamping axle  5  are connected in a rotationally fixed manner to each other. Furthermore, several openings  21  for mounting further components are provided on the first pivoting lever  2 .  FIG. 2  further shows a washer  9  which rests on the loop  4 . 
     The clamping axle  5  comprises a cylindrical section  50  which is surrounded by a circular receptacle  40  on the loop  4 . A retaining section  51  for a switching mechanism is further formed between the cylindrical section  50  and the jagged pin  52 . 
     The second pivoting lever  3  comprises a bearing opening  30 , which is placed on the pivot  6  on the loop  4 . An upwardly protruding pin  8  is further arranged on the loop  4 , which is inserted into an opening  31  in form of an oblong hole or an opening formed with play in relation to the pin  8 . As a result, the second pivoting lever  3  can be pivoted relative to the loop  4  in a predetermined angular range. The second pivoting lever  3  further comprises openings  32  for mounting further components. 
     The loop  4  and the clamping axle  5  form a blocking device, by means of which a rotational motion of the first pivoting lever  2  in relation to the second pivoting lever  3  is blocked in a first direction of rotation and is enabled in a second direction of rotation. The blocking device can be deactivated for an adjusting process via a switching element  10 . The switching element  10  is arranged adjacent to a control element  14 , which is connected via a coupling in form of a corrugated spring  15  to the first pivoting lever  2 . The coupling can also be realised in a different way, e.g. as a friction coupling. The corrugated spring  15  is clampingly inserted between a retaining ring  16 , which is adjacent to the clamping axle  5 , and the control element  14 , so that during a rotational motion of the clamping axle  5  the control element  14  is moved by frictional forces with the clamping axle  5  and the first pivoting lever  2  until a further rotational motion is prevented, e.g. by a stop. In addition, a cover  17  is present so that the pivoting mechanism does not come into contact with other components such as fillings of upholstered pieces of furniture for example. 
       FIG. 3  shows the loop  4  in detail. The loop  4  comprises a first arm  41  which is formed in an L-shaped manner and on the outer leg of which the pivot  6  and the pin  8  are arranged. The first arm  41  further surrounds a first part of the clamping axle  5 , wherein a second arm  42  is connected to the first arm  41 . A receptacle  46  is provided on the second arm  42 , into which the projection  7  of the second pivoting lever  3  is inserted. The first arm  41  and the second arm  42  of the loop  4  are movable relative to each other, wherein a radial gap  44  is formed adjacent to the receptacle  40  between the arms  41  and  42 . Furthermore, a gap  43  formed in an angular and preferably rectangular manner is provided between the arms  41  and  42 , so that a movement of the arms  41  and  42  is possible in a specific angular range, e.g. between 0.5° and 5°. 
       FIG. 4  shows a loading of the second pivoting lever  3  relative to the first pivoting lever  3  in the clamping direction. When the force F 1  is applied to the left in  FIG. 4 , the second pivoting lever  3  is slightly twisted about the pivot  6 , so that the projection  7  in the receptacle  46  on the loop  4  acts on the second arm  42  of the loop  4  with the force F 2 . The second arm  42  is thus pressed to the first arm  41  of the loop, and the radial gap  44  between the arms  41  and  42  is reduced to the width b. By compressing the arms  41  and  42 , the loop  4  engages around the cylindrical section  50  of the clamping axle  5  in a clamping fashion, so that a relative movement between the loop  4  and the clamping axle  5  is prevented. The loading with the force F 1  thus prevents a rotational motion of the second pivoting lever  3  relative to the first pivoting lever  2 . 
       FIG. 5  shows a loading of the second pivoting lever  3  against the first direction of rotation, i.e. in the second direction of rotation. The force F 1 * presses to the right in  FIG. 5 , so that the second pivoting lever  3  is slightly twisted about the pivot  6  and the projection acts with a force F 2 * on the second arm  42  of the loop  4 . The second arm  42  is slightly pressed away from the first arm  41  by the force F 2 *, so that the gap  44  broadens to the width B. By spreading the first arm  41  in relation to the second arm  42 , a rotational motion between the loop  4  and the clamping axle  5  is enabled. The rotational motion can occur at any desired angle, e.g. also by more than 360°. 
     The function of the switching element  10  is explained in closer detail by reference to  FIGS. 6 and 7 .  FIGS. 6A and 6B  show the switching element  10  in an inactive position, in which blocking of the rotational motion of the first pivoting lever  2  in relation to the second pivoting lever  3  in the first direction of rotation is enabled and no blocking occurs in the second direction of rotation, as explained in  FIGS. 4 and 5 . The switching element  10  is pretensioned by a spring  13  to this inactive position, wherein the spring  13  is supported on a base  47  of the arm  41  of the loop  4 . The switching element  10  is situated adjacent to the radial gap  44  between the first arm  41  and the second arm  42 . Furthermore, the switching element comprises a tubular receptacle  12  for the spring  13  and a middle section which protrudes into the gap  44 . An upper pin  11  of the switching element  10  protrudes upwardly beyond the loop  4  and rests on a web  18  of the control element  14 . A limit stop  19  is integrally attached to the web  18 , which limits a rotational motion of the control element  14  relative to the switching element  10 . 
     In the inactive position, the middle section of the switching element  10  is situated with a wall  60  adjacent to a wall  48  on the second arm  42 . The wall  48  is formed in a setback manner, so that the gap  44  in the region of the wall  48  is greater than in the remaining area. The wall  48  is connected via a step  49  to a wall  55  of the arm  42 . If the wall  48  and the wall  60  are situated opposite each other, as illustrated in  FIG. 6B , the first arm  41  and the second arm  42  of the loop can be moved, as shown in  FIGS. 4 and 5 . In particular, the loop  4  can tightly clamp the clamping axle  5  when the arms  41  and  42  are moved towards each other. 
     In  FIGS. 7A and 7B , the first pivoting lever  2  was twisted in the second direction of rotation, by means of which the control element  14  was co-rotated with the annular section as a result of the coupling by the corrugated spring  15 . The switching element  10  is moved along the web  18  by twisting of the control element  14  and pressed by a guide bevel  25  on the web  18  into a receptacle  45  of the first arm  41  against the force of the spring  13 . The rotational motion of the control element  14  is terminated when a limit stop  26  adjacent to the guide bevel  25  reaches the pin  11  of the switching element  10 . The first pivoting lever  2  can then be moved relative to the second pivoting lever  3  further in the second direction of rotation, wherein the coupling with the control element  14  ensures that the control element  14  can remain in the fixed position. 
       FIG. 7B  shows that by pressing down the switching pin the wall  60  no longer rests on the widened wall  48  of the arm  42 , but was moved at least partly in the downward direction over the step  49 , so that the wall  60  now rests on the wall  55 . The switching element  10  is now fixed in a clamped fashion between the first arm  41  and the second arm  42 , and prevents that the first arm  41  and the second arm  42  are moved towards each other in order to produce a clamping connection between the loop  4  and the clamping axle  5 . If the first pivoting lever  2  is now moved relative to the second pivoting lever  3  in the first direction of rotation, there is no tight clamping of the loop  4  relative to the clamping axle, although according to  FIG. 4  a force of the second pivoting lever  3  is applied by the projection  7  onto the second arm  42  since the second arm  42  is blocked by the switching element  10 . As a result of the arrangement of the switching element  10  in the clamping position, a movement in the first direction of rotation can thus also occur because the blocking device is deactivated. 
     If the first pivoting lever  2  is now moved relative to the second pivoting lever  3  in the first direction of rotation, the switching element  10  remains fixed in a clamping fashion between the first arm  41  and the second arm  42  until the user moves the first pivoting lever  2  relative to the second pivoting lever  3  slightly in the second direction of rotation. The clamping of the switching elements  10  in the clamping gap  44  is then released by the expansion of the clamping gap  44  by the action of the force F 1  on the projection  7  and the arms  41  and  42  can spread apart slightly, which releases the wall  60  from the clamped fixing with the wall  55 , and the switching elements  10  can now be pressed upwardly out of the receptacle  45  as a result of the force of the spring  13 . As a result, the first arm  41  can now be compressed again relative to the second arm  42  under loading in the first direction of rotation and block the loop  4  on the clamping axle  5 . 
     In the illustrated embodiment, a corrugated spring  15  is used for coupling the control element  14  to the first pivoting lever  2  and the clamping axle  5 . It is obvious that other coupling elements can also be provided. 
     Furthermore, a different switching mechanism can be used instead of the illustrated switching element in order to block or deactivate a clamping effect of the loop  4  for an adjusting process. 
       FIGS. 8 to 14  show a second embodiment of a pivoting fitting  1 ′ in accordance with the invention. The pivoting fitting  1 ′ comprises a first pivoting lever  2  and a second pivoting lever  3 , which can be arranged in different angular positions relative to each other, as is shown in  FIGS. 8 to 11 . Other than in the first embodiment, the adjustment path of the pivoting levers  2  and  3  relative to each other is predetermined by limit stops in this pivoting fitting  1 ′. 
     The mechanical details of the pivoting fitting  1 ′ are shown in  FIG. 12 . 
     The first pivoting lever  2  comprises a hexagonal receptacle  20 ′, which can be inserted onto a hexagonal pin  52 ′ of the clamping axle  5 ′, so that the first pivoting lever  2  and the clamping axle  5 ′ are connected to each other in a rotationally fixed manner. Furthermore, a similarly hexagonal holding section  51 ′ is provided at the bottom end of the clamping axle  5 ′. 
     The second pivoting lever  3  is fixed to a loop  4 ′, which encloses with a cylindrical receptacle  40  a similarly cylindrical section  50 ′ of a clamping axle  5 ′. The second pivoting lever  3  is inserted into a slotted receptacle  62  on the loop  4 ′ and is rotatably mounted there. A bearing opening  30  is formed on the second pivoting lever  3  for this purpose, which is penetrated by a pivot  6 , which is inserted into an opening  61  on the loop  4 ′ and rotatably mounts the second pivoting lever  3 . The pivot  6  can be secured by a nut  64  with a washer  63  against axial displacement. Openings  32  for mounting further attachment parts are further formed on the second pivoting lever  3 , and a projection  7  is formed in the region into which the loop  4 ′ protrudes. 
     The loop  4 ′ and the clamping axle  5 ′ form a blocking device for the pivoting levers  2  and  3 , which blocks in a first direction of rotation and allows a rotation in a second direction of rotation, wherein the blocking device can be deactivated via a switching element  10 ′ for an adjusting process. The switching element  10 ′ is formed as a pin which is pretensioned by a spring  13  towards a control element  14 ′. The switching element  10 ′ is arranged in a receptacle  45  adjacent to a gap  44  between two arms  41  and  42  of the loop  4 ′. 
     The control element  14 ′ is rotatably mounted on the clamping axle  5 ′ and comprises an opening for this purpose, which is penetrated by a section  54  of the clamping axle  5 ′. The control element  14 ′ comprises two stops  56  and  57  on an annular section, which can rest on a projection  53  on the clamping axle  5 ′, so that the rotational range between the control element  14 ′ and the clamping axle  5 ′ is limited. As in the preceding embodiment, the control element  14 ′ comprises a web  18 ′ extending perpendicularly to the rotational axis of the clamping axle  5 ′, on which a guide bevel  25 ′ is integrally attached. The web  18 ′ and the guide bevel  25 ′ are used for switching the pretensioned switching element  10 ′ on the loop  4 ′. In order to avoid an axial displacement of the control element  14 ′, a retaining ring  16  is mounted adjacent to the control element  14 ′ on the section  54  of the clamping axle  5 ′. Furthermore, a spring  58  is arranged between two retaining rings  16 , wherein the spring  58  pretensions the control element  14 ′ in a direction of rotation. For this purpose, a bent end section  59  of the spring  58 , which is made of wire, is inserted into an opening on the web  18 ′, and an opposite end of the spring  58  is retained on a receptacle  46 ′ of the loop  4 . 
     In order to pretension the loop  4 ′ towards the first pivoting lever  2 , a corrugated spring  15  is provided on the loop  4 ′ on the side facing away from the pivoting lever  2 , which corrugated spring is arranged between two washers  9 ′. A retaining ring  16  is provided again on the axially outer side on a retaining section  51 ′ of the clamping axle  5 ′. 
     The actuation of the second pivoting lever  3  makes the projection  7  selectively compressing or widening the loop  4 ′, wherein the pivoting levers  2  and  3  are blocked relative to each other by the compression of the loop  4 ′. Only when the second pivoting lever  3  is pivoted in the opposite direction will the projection  7  press on the arm  42  of the loop  4 ′, so that it widens slightly and permits a pivoting movement. If the second pivoting lever  3  is now pivoted in the unblocked direction of rotation, then this can occur to such an extent until the control element  14 ′ moves with the stop  56  against the projection  53 . The control element  14 ′ is then no longer co-rotated under a further pivoting movement of the second pivoting lever  3 , but remains rigidly on the clamping axle  5 ′. The guide bevel  25 ′ thus comes into engagement with the switching element  10 ′, which is pressed downwardly, as shown in  FIGS. 13 and 14 . The switching element  10 ′ is pressed against the force of the spring  13  into the receptacle  45  on that the loop  4 ′. The arms  41  and  42  are held in the widened position as a result of the downward pressing of the switching element  10 ′, as was already explained for the first embodiment with reference to  FIGS. 7A and 7B . A return process can then be initiated until the control element  14 ′ moves with the second stop  57  against the projection  53 . The switching element  10 ′ is then displaced along the guide bevel  25 ′ during a further return movement of the second pivoting lever  3  and can reach the protruding position again as a result of the force of the spring  13 , so that the blocking effect is lifted. The second pivoting lever  3  can then be twisted in the opposite direction of rotation again while it is blocked in the direction of rotation for the return process. The adjustment range can be set individually by the stops  56  and  57  by using different control elements  14 ′. For the user the pivoting up to a stop is simpler in the handling than if no stop were present. 
     In  FIGS. 8, 9, 10, 11, 13 and 14  the first lever  2  is connected by the holding section  51 ′ to the clamping axle  5 ′.  FIG. 12  shows the receptacle  20 ′ of the first lever  2  above the pin  52 ′ of the clamping axle  5 ′ and can be connected thereto in a rotationally fixed manner. As a result, the pivoting fitting  1 ′ in  FIG. 12  can be used for the one side of the piece of furniture, e.g. in a backrest, or of the motor vehicle seat, and the pivoting fitting in  FIGS. 8, 9, 10, 11, 13 and 14  for the other side of the piece of furniture or the motor vehicle seat. The same applies to the pivoting fitting  1  of the first embodiment. It is only relevant that the respective receptacle  20 ,  20 ′ and the pin  52 ,  52 ′ or the retaining section  51 ,  51 ′ are fixed to each other in a rotationally fixed manner, especially by an interlocking connection. 
       FIG. 15  shows a piece of furniture  100  with several substantially identical pivoting fittings  1 . Two pivoting fittings  1  mount a headrest  101 , two pivoting fittings  1  an armrest  102 , and two pivoting fittings  1  a leg rest  103 . In order to avoid the use of right and left pivoting fittings, the first lever  2  can be arranged in a rotationally fixed manner on the pin  52  of the clamping axle  5  in a first pivoting fitting  1 , and in the second pivoting fitting  1  the first lever  2  can be arranged in a rotationally fixed manner on the opposite side of the clamping axle  5 , namely on the retaining section  51  of the clamping axle  5 . 
     LIST OF REFERENCE NUMERALS 
     
         
           1 ,  1 ′ Pivoting fitting 
           2  Pivoting lever 
           3  Pivoting lever 
           4 ,  4 ′ Loop 
           5 ,  5 ′ Clamping axle 
           6  Pivot 
           7  Projection 
           8  Pin 
           9  Washer 
           9 ′ Washer 
           10 ,  10 ′ Switching element 
           11  Pin 
           12  Receptacle 
           13  Spring 
           14 ,  14 ′ Control element 
           15  Corrugated spring 
           16  Retaining ring 
           17  Cover 
           18 ,  18 ′ Web 
           19  Stop 
           20 ,  20 ′ Receptacle 
           21  Opening 
           25 ,  25 ′ Guide bevel 
           26  Stop 
           30  Bearing opening 
           31  Opening 
           32  Opening 
           40  Receptacle 
           41  Arm 
           42  Arm 
           43  Gap 
           44  Gap 
           45  Receptacle 
           46 ,  46 ′ Receptacle 
           47  Base 
           48  Wall 
           49  Step 
           50 ,  50 ′ Section 
           51 ,  51 ′ Retaining section 
           52 ,  52 ′ Pin 
           53  Projection 
           54  Section 
           55  Wall 
           56  Stop 
           57  Stop 
           58  Spring 
           59  End section 
           60  Wall 
           61  Opening 
           62  Receptacle 
           63  Washer 
           64  Nut 
           100  Piece of furniture 
           101  Headrest 
           102  Armrest 
           103  Leg rest 
         F 1  Force 
         F 2  Force 
         F 1 * Force 
         F 2 * Force 
         b Width 
         B Width