Abstract:
In a vehicle seat, in particular a motor vehicle seat having a backrest and at least one headrest rod ( 10 ) that is slidingly guided relative to the backrest and is locked in an in-use position and can be unlocked by actuating at least one actuation element ( 21, 23 ), and also having at least one headrest ( 6 ) mounted on the headrest rod ( 10 ), the headrest being adjustable in height and removable by sliding the headrest rod ( 10 ), two different actuation elements ( 21, 23 ) or two different methods of actuating the actuation element are provided for the adjustment and removal processes.

Description:
RELATED APPLICATION  
       [0001]     The entire disclosure of DE 10 2005 012 896.3, which was filed Mar. 21, 2005, is incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to a vehicle seat, in particular a motor vehicle seat, having a backrest, at least one headrest rod that is slidingly guided in relation to the backrest and locked in an in-use position, and at least one headrest mounted on the headrest rod, wherein the headrest rod is unlockable by the actuation of an actuation element, and the headrest is adjustable in height and removable by way of sliding the headrest rod.  
         [0003]     In a vehicle seat of the type described immediately above, it is known that the height of the headrest can be adjusted by actuating the actuation element. If, in so doing, the headrest is pulled upwards beyond the highest adjustable level, it necessarily comes off its mounting. As the highest adjustable level is usually not known, this may occur totally inadvertently, in particular if, in order to save material, the rods used for supporting the headrest are very short. Reinstallation of the headrest is not only considered an inconvenience, but also involves a safety risk, in particular if the headrest is positioned above the highest adjustable level and just below the level where it will inevitably come off again.  
       BRIEF SUMMARY OF SOME ASPECTS OF THE INVENTION  
       [0004]     An aspect of the present invention is the provision of improvements to a vehicle seat of the type described above.  
         [0005]     In accordance with one aspect of the present invention, a vehicle seat, in particular a motor vehicle seat, has a backrest, at least one headrest rod that is slidingly guided in relation to the backrest and locked in an in-use position, and at least one headrest mounted on the headrest rod. The headrest rod is unlockable by the actuation of at least one actuation element, and the headrest is adjustable in height and removable by way of sliding the headrest rod. In one example, two different methods of actuating the same actuation element (e.g., a single or certain actuation element) are respectively provided for the adjustment and removal processes. In another example, two different actuation elements are respectively provided for the adjustment and removal processes.  
         [0006]     By providing two different actuation elements or two different methods of actuating the actuation element for the purpose of adjusting and removing the headrest, unintentional removal of the headrest during the adjustment process is avoided because the user must carry out a significantly different actuation in order to remove the headrest. Preferably at least one adjustment notch, more precisely one such notch per each level of adjustment, and at least one, preferably no more than one, stop notch are formed on the headrest rod, with the notches respectively interacting with a locking element of the actuation element to lock the headrest rod in place. When the headrest rod is locked by engagement in an adjustment notch, unlocking is accomplished by way of a first actuation element that is preferably easy for the user to access and that interacts by way of its locking element with the adjustment notch, or by actuating the (single) actuating element in a first particular way. When, on the other hand, the headrest rod is locked by engagement in the stop notch, unlocking is accomplished by way of the second actuation element whose own locking element interacts with the stop notch, or by actuating the (single) actuation element in a second particular way. The second actuation element preferably becomes accessible and/or actuatable when the interlocking with the stop notch occurs. The adjustment notches and stop notches may be formed on different sides of the same headrest rod (e.g., a certain headrest rod) or on different headrest rods, it being preferable in the first case that the actuation elements are actuated in different directions.  
         [0007]     The actuation element is movably located in a space-saving manner, preferably in a receptacle in the head section of a guide bushing in which the headrest rod is mounted. The actuation element is preferably supported and pretensioned (e.g., biased) with respect to the head of the bushing by way of at least one mounting spring. The actuation element is then held in its resting position by way of the mounting spring. The actuation element is then actuated correspondingly, preferably by pushing it against the force of the mounting spring. In the case of a single actuation element, the action element is actuated by two distinctly different methods of actuation, preferably by pressing and turning, or by turning it in two different directions.  
         [0008]     Other aspects and advantages of the present invention will become apparent from the following.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     Hereinafter, the present invention is described in more detail with reference to six exemplary embodiments illustrated in the drawings, in which:  
         [0010]      FIG. 1  shows a vertical cross section through a portion of the first exemplary embodiment in the in-use state;  
         [0011]      FIG. 2  shows a cross-section along the line II-II in  FIG. 1 , with an arrow indicating the possible direction of actuation during the adjustment process;  
         [0012]      FIG. 3  shows a cross-section along the line III-III in  FIG. 1 , with an arrow that is illustrated in dashed lines indicating the possible direction of actuation when removing the headrest, and dashed lines also illustrate the position of the second actuation element prior to actuation;  
         [0013]      FIG. 4  is a schematic view of a vehicle seat;  
         [0014]      FIG. 5  shows a vertical cross-section through a portion of the second exemplary embodiment in the in-use state;  
         [0015]      FIG. 6  shows a cross-section along the line VI-VI in  FIG. 5 , with an arrow indicating the possible direction of actuation during the adjustment process;  
         [0016]      FIG. 7  shows a cross-section along the line VII-VII in  FIG. 5 , with an arrow that is illustrated in dashed lines indicating the possible direction of actuation when removing the headrest, and dashed lines also illustrate the position of the second actuation element prior to actuation;  
         [0017]      FIG. 8  shows a vertical cross-section through a portion of the third exemplary embodiment in the in-use state;  
         [0018]      FIG. 9  shows a cross-section along the line IX-IX in  FIG. 8 , with an arrow illustrated by a continuous line indicating the possible direction of actuation during the adjustment process, and an arrow illustrated by dashed lines indicating the possible direction of actuation during removal of the headrest;  
         [0019]      FIG. 10  shows a vertical cross-section through a portion of the fourth exemplary embodiment in the in-use state;  
         [0020]      FIG. 11  shows a cross-section along the line XI-XI in  FIG. 10 ;  
         [0021]      FIG. 12  shows a cross-section corresponding to  FIG. 10  during the adjustment process;  
         [0022]      FIG. 13  shows a cross section along the line XIII-XIII in  FIG. 12 , with an arrow indicating the direction of actuation during the adjustment process;  
         [0023]      FIG. 14  shows a cross-section corresponding to  FIGS. 10 and 12  during the removal of the headrest;  
         [0024]      FIG. 15  shows a cross-section along the line XV-XV in  FIG. 14 , with an arrow illustrated by dashed lines indicating the direction of actuation when removing the headrest;  
         [0025]      FIG. 16  shows a vertical cross-section through a portion of the fifth exemplary embodiment in the in-use state;  
         [0026]      FIG. 17  shows a cross-section along the line XVII-XVII in  FIG. 16 , with an arrow indicating the possible direction of actuation during the adjustment process;  
         [0027]      FIG. 18  shows a cross-section corresponding to  FIG. 17 , with an arrow illustrated by dashed lines indicating the possible direction of actuation when removing the headrest;  
         [0028]      FIG. 19  shows a vertical cross-section through a portion of the sixth exemplary embodiment in the in-use state;  
         [0029]      FIG. 20  shows a cross-section along the line XX-XX in  FIG. 19 , with an arrow indicating the direction of actuation during the adjustment process; and  
         [0030]      FIG. 21  shows a cross section corresponding to  FIG. 20 , with an arrow illustrated by dashed lines indicating the direction of actuation when removing the headrest. 
     
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS  
       [0031]     In the following, reference is made in greater detail to the drawings, in which like numerals refer to like parts throughout the several views. In all the exemplary embodiments, a vehicle seat  1  of a motor vehicle comprises a headrest  6  mounted on a backrest  3 . The headrest  6  is attached in a known manner to at least one, and in the present case to two metal headrest rods, each of which is mounted in a linearly sliding manner in a plastic guide bushing in the backrest  3 . By these means, the headrest  6 , which is locked in an in-use position, is adjustable in height and can also be fully removed.  
         [0032]     In the first exemplary embodiment, several adjustment notches  12  are arranged equidistantly apart on one side of one of the two headrest rods  10 , and on the other side a stop notch  14  is formed below the lowest adjustment notch  12 . The associated guide bushing  15  comprises a bushing head  17  within which are formed, at various heights and on opposite sides, two open receptacles  19  respectively for an upper, first actuation element  21 , and a lower, second actuation element  23 . Both actuation elements  21  and  23  comprise a locking element  25  aligned perpendicularly to the headrest rod  10  and consisting, for example, of a piece of metal wire or rod. Except for their locking elements  25 , the actuation elements  21  and  23  are made of plastic. The actuation elements  21  and  23  are respectively arranged within the receptacles  19 . For each actuation element  21  and its respective guide bushing  15 , the actuation element  21  is biased by way of a mounting spring  27 , namely by the tendency of the mounting spring  27  to expand, in a manner that urges the actuation element away from a portion of the guide bushing. The locking element  25  is in each case arranged on the side of the headrest rod  10  facing away from the open part of the receptacle  19  and facing towards the closed part of the receptacle  19 .  
         [0033]     When the headrest is in use, the locking element  25  of the first actuation element  21  engages in an adjustment notch  12 , as a result of which the headrest rod  10 , and thus the headrest  6 , is locked in place. While the first actuation element  21  is accessible to the user and flush with the bushing head  17 , the second actuation element  23  is located completely within its receptacle  19 . In order to adjust the headrest  6 , the first actuation element  21  is actuated, i.e. pressed deeper into its receptacle  19  (e.g., moved in a nonrotary direction), so that the locking element  25  is disengaged from the adjustment notch  12 . It is now possible to slide the headrest rod  10  within the guide bushing  15 , thus permitting the height of the headrest  6  to be adjusted. The adjustment notches  12  are preferably beveled downwards so that the headrest rod  10  can be pulled upwards, i.e. further extended, even without actuating the first actuation element  21 .  
         [0034]     In order to remove the headrest  6 , the headrest rod  10  is pulled upwards until the lowest adjustment notch  12  passes by at least the first actuation element  21  and emerges at the top from the bushing head  17 . As soon as the stop notch  14  reaches the second actuation element  23 , the associated mounting spring  27  displaces the second actuation element  23  whose locking element  25  then engages in the stop notch  14 . The headrest rod  10  is thus locked once more. The second actuation element  23  now projects laterally from the bushing head  17 . By actuating, i.e. pressing (e.g., moving in a nonrotary direction), the second actuation element  23 , the locking element  25  is disengaged from the stop notch  14 , and as a result the headrest rod  10  can be pulled further upwards until it finally leaves the guide bushing  15 . The stop notch  14  is preferably beveled upwards so that the headrest rod  10  can be pushed down again, i.e. re-inserted, without actuating the second actuation element  23 .  
         [0035]     Except where stated otherwise below, the second exemplary embodiment is the same as the first exemplary embodiment, for which reason identical and identically acting components bear reference numbers raised by 100. The adjustment notches  112  are in this case formed on a first headrest rod  110 . The first headrest rod  110  is introduced into the guide bushing  115 , in the head  117  of which the first actuation element  121  is mounted with a mounting spring  127  in a receptacle  119 , for locking the first headrest rod  110  by way of its actuation element  125 . On the other hand, the stop notch  114  is formed on a second headrest rod  130 . The second headrest rod  130  is inserted into a guide bushing  115  of identical design to the guide bushing  115  used for the first headrest rod  110 . With the exception of the displacement corresponding to the thickness of the locking element  125 , the second actuation element  123  is identical to the first actuation element  121 , and alternatively the second actuation element  123  can be completely identical to the first actuation element  121 . The second actuation element  123  is arranged and mounted in the same way as the first actuation element  121 , except that the second actuation element  123  is not locking the second headrest rod  130  while the first actuation element  121  is locking the first headrest rod  110 . In both of the first and second exemplary embodiments the mode of functioning, including the mode of actuation, is the same—except for the circumstances determined by the spatially separate arrangement of the actuation elements  121  and  123 .  
         [0036]     Except where stated otherwise below, the third exemplary embodiment is similar in design to the first and second exemplary embodiments, for which reason identical and identically acting components bear reference numbers raised by 200 and 100 respectively. As in the case of the first exemplary embodiment, adjustment notches  212  are formed on one side of the (first) headrest rod  210  and on the opposite side a stop notch  214  is formed. The headrest rod  210  is introduced into the guide bushing  215 . The first actuation element  221  is mounted in a receptacle  219  in the head  217  of the guide bushing  215 ; the first actuation element  221  is accessible to the user. The first actuation element  221  is connected, by way of two parallel-arranged energy-storing elements  233  (e.g., tension springs) that enclose the headrest rod  210  between them, to the second actuation element  223 . The second actuation element  223  is arranged completely inside the receptacle  219  so that the second actuation element  223  is inaccessible to the user. The second actuation element  223  is biased by a mounting spring  227 , namely by the tendency of the mounting spring  227  to expand, in a manner that urges the actuation element away from a portion of the head  217  of the guide bushing  215 . When the headrest is in use, the locking element  225  of the second actuation element  223  locks the headrest rod  210  in place.  
         [0037]     In order to adjust the headrest, the first actuation element  221  is actuated in a first manner, i.e. in the present case it is pressed, as a result of which the motion is transmitted to the second actuation element  223  by the compressed coils of the energy-storing elements  233 , so that the locking element  225  of the second actuation element  223  is disengaged. The headrest rod  210  can now be adjusted in height. In order to remove the headrest, the headrest rod  210  is first pulled upwards until the locking element  225  of the first actuation element  221  engages in the stop notch  214 . By actuating the first actuation element  221  in a second manner, in the present case by pulling (e.g., moving in a nonrotary direction), the locking element  225  is again disengaged and the headrest rod  210  can be pulled further upwards.  
         [0038]     Except where stated otherwise below, the fourth exemplary embodiment is similar in design to the first, second and third exemplary embodiments, for which reason identical and identically acting components bear reference numbers raised by 300, 200 and 100 respectively. As in the first exemplary embodiment, adjustment notches  312  are formed on one side of the (first) headrest rod  310 . On the same side, a stop notch  314  is formed below the lowest adjustment notch  312 . The headrest rod  310  is introduced into the guide bushing  315 . The user-accessible first actuation element  321  is mounted in a receptacle  319  in the head  317  of the guide bushing  315 . The first actuation element  321  is biased by way of a mounting spring  327 , namely by the tendency of the mounting spring  327  to expand, in a manner that urges the actuation element away from a portion of the head  317  of the guide bushing  315 . When the headrest is in use, the locking element  325  of the first actuation element  321  engages in one of the adjustment notches  312 . The second actuation element  323  is mounted within the first actuation element  321 . The second actuation element  323  engages one end of a rocker element  335 . The rocker element  335  is pivotably mounted on the guide bushing  315 . The other end of the rocker element  335  bears a further locking element  325  that is pretensioned by a spring against (e.g., biased toward) the headrest rod  310 .  
         [0039]     In order to adjust the headrest, the first actuation element  321  is actuated, i.e. in the present case it is pressed, causing its locking element  325  to disengage, so that the height of the headrest rod  310  can be adjusted. To remove the headrest, the headrest rod  310  is first pulled upwards until the locking element  325  on the rocker element  335  engages in the stop notch  314 . By actuating the second actuation element  323 , in the present case by pulling it outwards relative to the first actuation element  321 , the rocker element  335  is pivoted and its locking element  325  is again disengaged so that the headrest rod  310  can be pulled further upwards.  
         [0040]     Except where stated otherwise below, the fifth exemplary embodiment is similar in design to the preceding embodiments, for which reason identical and identically acting components bear reference numbers that are in each case raised by 100. The (first) headrest rod  410  is again provided with several adjustment notches  412 . The stop notch  414  is arranged beneath the lowest adjustment notch  412 , and it is offset at an angle of slightly more than 90° with respect to the adjustment notches  412 . The headrest rod  410  is inserted into the guide bushing  415  in the head  417  of which is mounted, in a receptacle  419 , the user-accessible (first) actuation element  421 . The actuation element  421  is biased by way of a first mounting spring  427 , namely by the tendency of the first mounting spring  427  to expand, in a manner that urges the actuation element away from another portion of the head  417  of the guide bushing  415 . The actuation element  421  is also biased by way of a second mounting spring  437 , namely by the tendency of the second mounting spring  437  to expand, in a manner that urges the actuation element away from a portion of the head  417  of the guide bushing  415 . The second mounting spring  437  is arranged perpendicularly to the first mounting spring  427 . When the headrest is in use, the locking element  425  of the actuation element  421  engages in one of the adjustment notches  412 .  
         [0041]     In order to adjust the headrest, the actuation element  421  is actuated in a first manner, i.e. in the present case it is pressed (e.g., moved in a nonrotary direction) against the first mounting spring  427 , thereby causing the locking element  425  to disengage, so that the height of the headrest rod  410  can be adjusted. More specifically,  FIG. 17  shows the locking element  425  engaging an adjustment notch  412 , and the arrow indicates how to press the actuation element  421  for disengaging the locking element  425  from the adjustment notch  412 .  
         [0042]     To remove the headrest, the headrest rod  410  is first pulled upwards until an inner edge of the actuation element  421 , which is offset by 90° relative to the locking element  425 , engages in the stop notch  414 . The inner edge of the actuation element  421 , which is offset by 90° relative to the locking element  425  and engages in the stop notch  414 , can be referred to as a locking element portion (e.g., a second locking element) of the actuation element  421 . By actuating the actuation element  421  in a second manner, in the present case by rotating it (e.g., moving it in a rotary direction) around the headrest rod  410  against the force of the second mounting spring  437 , the inner edge of the actuation element  421  (e.g., the second locking element of the actuation element  421 ) is disengaged from the stop notch  414 , so that the headrest rod  410  can be pulled further upwards. More specifically,  FIG. 18  shows the inner edge of the actuation element  421  (e.g., the second locking element of the actuation element  421 ) engaged in the stop notch  414 , and the arrow indicates how to rotate the actuation element  421  for disengaging the actuation element  421  (e.g., the second locking element of the actuation element  421 ) from the stop notch  414 .  
         [0043]     Except where stated otherwise below, the sixth exemplary embodiment is similar in design to the preceding exemplary embodiments, and in particular to the fifth exemplary embodiment, for which reason identical and identically acting components bear reference numbers that are in each case raised by 100. The (first) headrest rod  510  is again provided with several adjustment notches  512 . The stop notch  514  is formed slightly offset, for example by 30°, with respect to the adjustment notches  512 , and it is below the lowest adjustment notch  512 . The headrest rod  510  is inserted into the guide bushing  515  in the head  517  of which is mounted, in a receptacle  519 , the user-accessible (first) actuation element  521 . The actuation element  521  is biased by way of a first mounting spring  527 , namely by the tendency of the first mounting spring  527  to expand, in a manner that urges the actuation element away from a portion of the head  517  of the guide bushing  515 . When the headrest is in use, the locking element  525  of the actuation element  521  engages in one of the adjustment notches  512 .  
         [0044]     For the purpose of adjusting the headrest, the actuation element  521  is actuated in a first manner, i.e. in the present case, seen from above, it is rotated counter-clockwise (e.g., moved in a rotary direction) around the headrest rod  510 , thereby causing the locking element  525  to disengage from the respective adjustment notch  512 , so that the height of the headrest rod  510  can be adjusted. More specifically,  FIG. 20  shows the actuation element  521  after rotating and disengaging the locking element  525  from an adjustment notch  512 , and the arrow indicates how the actuation element  521  was rotated counter-clockwise, as seen from above, around the headrest rod  510 . During the engagement of the locking element  525  and the adjustment notch  512 , the actuation element  521  had a position similar to its position in  FIG. 21 .  
         [0045]     To remove the headrest, the headrest rod  510  is first pulled upwards until the locking element  525  of the actuation element  521  engages in the stop notch  514 . By actuating the actuation element  521  in a second manner, in the present case by rotating it clockwise (e.g., moving it in a rotary manner), as seen from above, around the headrest rod  510 , the locking element  525  disengages from the stop notch  514  so that the headrest rod  510  can be pulled further upwards. More specifically,  FIG. 21  shows the actuation element  521  after rotating and disengaging the locking element  525  from the stop notch  514 , and the arrow indicates how the actuation element  521  was rotated clockwise, as seen from above, around the headrest rod  510 . During the engagement of the locking element  525  and the stop notch  514 , the actuation element  521  had a position similar to its position in  FIG. 20 .  
         [0046]     It will be understood by those skilled in the art that while the present invention has been discussed above with reference to exemplary embodiments, various additions, modifications and changes can be made thereto without departing from the spirit and scope of the invention as set forth in the following claims.