Patent Publication Number: US-2010109388-A1

Title: Vehicle seat

Description:
The present invention relates to a vehicle seat pursuant to the introductory portion of claim  1 . 
     Vehicle seats having various actuator-operated adjustments are known. Thus, for example, the backrest, after being released, can be actuator-operated out of a locked, upright position of use into a functional position. Furthermore known are electrical longitudinal adjustments of the seat frame relative to the chassis, electrical seat cushion adjustments, lordosis adjustments and head support adjustments. In addition to the position of use, certain functional positions, in particular for safety reasons, can also be locked in position, so that for the adjustment first the locking has to be released. This is generally effected by manual actuation of a release mechanism. After the release, the actuator-operated adjustment is effected by actuating a further control element, e.g. a switch. Electric motors are generally used as actuators. In this connection, systems having two electric motors are also known, whereby the first electric motor effects the release, and subsequently the second electric motor effects the adjustment. The capital expenditure necessary for this is, however, relatively high, and thus expensive. In addition, considerable installation space is required for the installation of various adjustments. 
     An apparatus for locking a foldable backrest of a vehicle seat is known from DE 102 11 400 B4. The electrical locking operates via a detent and a bolt. In addition, a blocking mechanism is provided. 
     U.S. Pat. No. 7,118,178 B2 shows a foldable vehicle seat according to which an electrical folding forward is effected by means of a planetary gear system. No locking of the position of use is provided. 
     DE 195 41 221 C2 discloses an apparatus for facilitating access to the rear seats of a two-door motor vehicle, according to which after a manual release an electric motor operated adjustment is effected. 
     The object of the present invention is to embody a vehicle seat of the aforementioned general type in such a way that in the folded-forward position of the backrest (cargo-position), an additional locking is accomplished. 
     This object is realized by the features of claim  1 . Advantageous and expedient further developments of the realization of the object are provided in the dependent claims. 
     With a vehicle seat having a plurality of seat parts and a locking device for locking at least one adjustable seat part, the invention proposes embodying and arranging an actuator for the adjustment of the at least one seat part in such a way that by means of successive partial movements of the actuator, the adjustable seat part can be unlocked from a locked first position (for example starting position or basic position), can be shifted from the unlocked first position into a second position (for example functional position), and can again be locked in the second position. Depending upon the starting position, the first position can be the basic or starting position, or also the functional position, and the second position can be the functional position or the basic or starting position. The functional position can be the cargo position, the easy-entry position, the table position, the adjustment position for the seat cushions, the head supports, etc. 
     For this purpose, pursuant to a further development of the realization of the object, a control member that can be actuated by the actuator is provided, by means of which the locking device can be shifted between its locking position and its unlocking or release position, and vice versa. 
     The inventive configuration has the advantage that with only one actuator, the pertaining seat part of the vehicle seat, in particular a pivotable backrest, can, by means of successive partial movements of the actuator, be transferred or converted from the position of use into a functional position, and vice versa, whereby in the functional position in addition a locking is achieved. With a backrest, the functional position is preferably the cargo position. 
    
    
     
       The invention will be explained in greater detail subsequently with the aid of the accompanying drawing, which shows one exemplary embodiment and in which: 
         FIG. 1  is a schematic illustration of a pivotable backrest of a vehicle seat in a locked position of use, 
         FIG. 2  shows the backrest of  FIG. 1  in the unlocked state, 
         FIG. 3  shows the backrest of  FIG. 1  or  FIG. 2  in the unlocked folded forward state, and 
         FIG. 4  shows the backrest of  FIG. 3  in the locked state. 
     
    
    
     Identical components, and components that correspond to one another, are provided with the same reference numerals in the figures of the drawings. 
     The drawings, in a side view, schematically show parts of a vehicle seat having a backrest  2  that is disposed on a bracket  6  of a seat part  8  of the vehicle seat so as to be pivotable about an axis  4 . 
     A control member  10  in the form of a cam is disposed on the bracket  6  so as to be rotatable about an axis  12 . The cam  10  is operatively connected with a locking device for the catching or locking and the unlocking or release of the backrest  2 . The locking device is comprised of a dual-arm pawl or detent  16  that is connected with the bracket  6  so as to be pivotable about an axis  18 . 
     The detent  16  has a slightly concavely curved configuration relative to the axis  4 , and is provided with a detent arm  20  that faces toward the cam and a detent arm  22  that faces away from the cam. The detent arm that faces toward the cam is provided with a tooth construction  24  that faces toward the backrest. The free end of the detent arm  22  that faces away from the cam is provided with an angled-off portion  26  that faces toward the backrest. Associated with the tooth construction  24  and the angled-off portion  26 , which forms a tooth, is a tooth element  28  that is formed on the backrest. 
     The detent arm  20  that faces toward the cam is provided on one side with a control curve  32  that is in operative connection with the cam  10  and ends at a nose  34  that serves as an abutment for the cam. 
     In its position of use, the back of the backrest  2  rests against a stop  36 , which limits the pivoting movement into the upright position of use. 
     An actuator in the form of an electric motor  38  is provided that is embodied as a spindle motor and drives a spindle  40 , one end  42  of which is connected with the control member, i.e. the cam,  10  in a pivot joint  44 , and the other end  46  of which is connected with the backrest  2  in a pivot joint  48 . The spindle  40  adjusts the distance between the pivot joints  44  and  48 . 
     In the locked position of use of the backrest pursuant to  FIG. 1 , the spindle  40  is in its maximum retracted position, i.e. with the minimum distance between the pivot joints  44  and  48 . In this locked position of use, the locking of the backrest is effected by engagement of the tooth construction  24  of the detent  16  into the tooth element  28  of the backrest. In this state, a control nose  50  of the cam  10  rests against a portion of the control curve  32  that is spaced from the abutment, i.e. the nose,  34 . 
     Pursuant to the present invention, when current flows through the electric motor  38 , it functionally carries out successive partial movements. In a first partial movement, as shown in  FIG. 2 , by extending the spindle  40  the cam  10  is pivoted in the clockwise direction in the drawing, whereby the control nose  40  of the cam  10  slides along the control curve  32  until the control nose  50  of the cam arrives at the abutment  34  of the detent  16 , so that by means of a further extension of the spindle  40 , the detent  16  is pivoted in the counter clockwise direction of the drawing, as a result of which the tooth construction  24  of the detent pivots out of the tooth element  28  of the backrest  2  until the angled-off portion  26  of the detent arm  22  comes to rest against the backrest  2 , as shown in  FIG. 2 . 
     From the unlocked basic position of the backrest  2  illustrated in  FIG. 2 , by means of a further extension of the spindle toward the top, accompanied by an increase of the distance between the pivot joints  44  and  48 , the backrest can be folded toward the front into a cargo position, which is illustrated in  FIGS. 3 and 4 . 
     The forward folding movement of the backrest  2  is delimited by a stop  52  on the bracket. 
     In the folded forward functional position of the backrest  2  illustrated in  FIG. 3 , the tooth construction  24  of the detent  16  is initially out of engagement with the tooth element  28  of the backrest. By means of a further extension of the spindle  40 , the control nose  50  of the control cam  10  presses against the abutment  34  of the detent  16 , as a result of which the latter is pivoted in the counter clockwise direction and via its angled-off portion  26 , which is formed at the free end of the detent arm  22  and forms a locking tooth, engages into the tooth element  28  of the backrest. The backrest  2  is thereby locked in the folded forward functional position (cargo position), which is illustrated in  FIG. 4 . 
     To transfer the backrest  2  out of the locked functional position of  FIG. 4  into the locked basic position of  FIG. 1 , by actuating the actuator, i.e. the electric motor,  38 , initially by retracting the spindle  40  the control curve  32  is acted upon by the control nose  50  of the cam  10 , as a result of which the locking detent  16  is pivoted in the clockwise direction and the angled-off portion  26  of the detent  16  disengages or withdraws from the tooth element  28  of the backrest, so that the backrest is unlocked. By means of a further retraction of the spindle, as a result of which the distance between the two pivot joints  44  and  48  is reduced, the backrest is returned into the position of use illustrated in  FIGS. 1 and 2  until the backrest  2  arrives at the stop  36 . In this return phase the backrest is still unlocked. By further retraction of the spindle  40 , as shown in  FIG. 1 , the cam  10  is pivoted in the counter clockwise direction, so that the control nose  50  of the cam  10  presses against the control curve  32  of the detent  16 , and the tooth construction  24  catches or engages in the tooth element  28 , as a result of which the backrest  2  is locked. With this, one movement cycle is completed. 
     In the event that not only the backrest, but also a further part of the vehicle seat, e.g. a seat cushion frame, is to be adjusted, the pivot connection  48 , instead of being directly on the backrest  2 , can be on another pivot member, so that by means of this pivot member not only the backrest but also the further seat part (seat cushion frame) can be adjusted. As a result, an adjustment of the backrest and of the seat cushion frame can, for example, be achieved simultaneously in order to achieve a cargo position with seat cushion frame adjusted toward the front and downwardly, and with folded forward backrest with horizontal upper side.