Patent Publication Number: US-2011074199-A1

Title: Adjustable vehicle seat and method

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a National Stage filing of International Application No. PCT/EP2007/000204, filed on Jan. 11, 2007, titled “Lowerable Vehicle Seat with a Collapsible Backrest Part and Associated Method” which claims priority to German Patent Application No. DE 10 2006 001 591.6, filed Jan. 11, 2006, the entire disclosures of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to a vehicle seat, in particular to a vehicle seat which is adjustable within multiple positions and a method therefore. 
     Vehicle seats typically offer a high level of comfort for vehicle users. At the same time, the vehicle seat should be compact, functional and cost-effective to produce. The seat should also be intuitive to operate, with minimal effort. The seat may be multi-positional, such as having a backrest can be folded forward, with the seat part simultaneously lowered. By lowering the seat to floor level, a level surface may be created. In another example, the seat may be raised to provide a table surface. In still another example, the height-adjustable vehicle seat may partially compensate for the weight of the user sitting on the seat and thereby make the adjustment of the seat easier. 
     While these seats are functional, they may not be not compact in a stowed position and do not offer both simple and intuitive height adjustability of the vehicle seat in a seated position. Thus, there is a need in the art for a compact seat that is multi-positional with minimal user effort and in an ergonomic manner. 
     SUMMARY 
     Accordingly, an adjustable seat for a vehicle includes a seat part that is moveable between a first seat position and a second seat position. The first seat position is spaced a first predetermined distance from a floor of the vehicle and the second seat position is spaced a second predetermined distance from the floor of the vehicle. A backrest pivotally connected to the seat part about a pivot axis. An adjusting device is operatively connected to the seat part for moving the seat part between the first seat position and the second seat position. The adjusting device includes an energy storage mechanism that exerts a variable first force on the seat part by pivoting the backrest from a folded over position to an upright position to move the seat part from the second seat position to the first seat position. 
     Other features and advantages of the present disclosure will be readily appreciated, as the same becomes better understood in view of the subsequent description taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a vehicle seat in a first seat position. 
         FIG. 2  is a side view of the backrest partially folded over in the first seat position for the vehicle seat of  FIG. 1 . 
         FIG. 3  is a side view of a folded over backrest in the first seat position for the vehicle seat of  FIG. 1 . 
         FIG. 4  is a side view of the vehicle seat of  FIG. 1  in a second seat position. 
         FIG. 5  is a side view of the vehicle seat of Figure illustrating another adjusting mechanism for varying the seat position. 
         FIG. 6  is a side view of the vehicle seat illustrating a control mechanism for the vehicle seat of  FIG. 5 . 
         FIG. 7  is another side view of the vehicle seat of  FIG. 5  illustrating the adjustment mechanism for varying the seat position. 
         FIG. 8  is another side view of the vehicle seat of  FIG. 7  illustrating the backrest in an upright position. 
         FIG. 9  is a side view of another example of an adjustment mechanism for varying the seat position. 
         FIG. 10  is a side view of the adjusting mechanism of  FIG. 9  with the seat in a second seat position. 
     
    
    
     DESCRIPTION 
     Referring to  FIG. 1 , a seat  1  for a vehicle is illustrated. The vehicle seat  1  may be a vehicle seat for the first, second or third row of a motor vehicle. The vehicle seat is multifunctional, and can be placed into various positions, such as a compact, stowed or lowered position. In such a position for example, a flat floor space is created in the forward direction. In another position, the vehicle seat can, with the back rest in a folded-over position, be used as a table. 
     The vehicle seat  1  includes a seat part  2  and a backrest  3 , with the backrest  3  being movable relative to the seat part  2 . The seat part  2  has a first main seat surface  20  which may be padded. The backrest  3  forms a second main seat surface  30  which may likewise be padded. In  FIG. 1 , the first main seat surface  20  runs substantially horizontally, or parallel to the seat part  2 , while the second main seat surface  30  is substantially parallel to the backrest  3 . The backrest  3  may be pivotable about a pivot axis  25  which runs substantially parallel both to the first and also to the second main seat surfaces  20 ,  30 . The backrest  3  may therefore be pivoted onto the first main seat surface  20 , or onto the seat part  2 , by being pivoted about the pivot axis  25  from an upright position to a folded over position. In the folded over position, an outer surface  31  of the backrest  3  is substantially horizontal to a floor  11  of the vehicle. 
     The vehicle seat  1  also includes an adjustment device  4  for varying a position of the seat. For example, a height of the seat part or an inclination of the backrest may be varied. In this example, the adjustment device  4  includes a plurality of members or links which are secured to a seat subassembly  10  that is mounted to a floor of the vehicle. The adjustment device  4  includes a front link  41  and a rear link  42  that rotates relative to the seat part  2  and relative to the seat subassembly  10  of the vehicle to provide a height adjustment or an incline adjustment of the seat part  2 , or of the seat part  2  together with the backrest  3 . In another example, the adjustment device  4  provides an incline adjustment of the seat using a single pair of links. In another example, the front and rear links  41 ,  42  are provided substantially in pairs at the sides of the vehicle seat  1 . However, in another example, a single link at the front or a single link at the rear, or else with a single link both at the front and at the rear of the seat is utilized. 
     The adjustment device  4  is connected to the seat part  2 , for example using tubular components that are operatively connected to the links  41 ,  42 . Tubular components are illustrated in  FIG. 1  by the reference sign  43  for the front link(s)  41  and with the reference sign  44  for the rear link(s)  42 . 
     The adjustment device includes an energy storage mechanism  5 , which moves the seat part  2  between predetermined seat positions. In the first position, the seat part  2  is spaced a predetermined distance apart from the floor  11  of the vehicle and is located for receiving a seated user. Various types of energy storage mechanisms may be utilized to facilitate movement of the seat between the seat positions, such as a spring or the like. An example of an energy storage mechanism is a torsion spring  5 . The torsion spring  5  of this example has a torsional axis which is substantially parallel and concentric with respect to the rear tubular component  44 , The torsion spring also includes a lever arm  55 , by which the torsional spring  5  can be rotated and thereby loaded or unloaded. The adjustment device  4  also includes a control member  34  having a control surface  35 , and that is operatively connected to the backrest  3 , such that the lever arm  55  of the spring  5  may be moved by the control surface  35  of the control member  34  to change the force action exerted by the spring  5 . 
     Referring to  FIG. 2 , the vehicle seat  1  with the seat part  2 , the backrest  3 , the pivot axis  25 , the control element  34 , the adjustment device  4  and the spring  5  are illustrated with the backrest pivoted by a predetermined angle  26 ′ in the direction of the seat part  2 . In this position, the control means  34  and the control surface  35  of the control means  34  are likewise pivoted together with the backrest  3 , such that the spring  5  and lever arm  55  are rotated counterclockwise relative to the position shown in  FIG. 1 . As a result, the spring  5  returns to a no load state. If the backrest  3  is pivoted even further to a predetermined inclined angle  26 , the spring  5  assumes an unloaded or relaxed position illustrated in  FIG. 3 . The predetermined inclined angle  26  separates a first pivoting range with the spring  5  activated from the second pivoting range with the spring  5  deactivated. 
     In operation, a first force action of the spring  5 , which causes the seat part  2  to be set in the first position, may be reduced or removed entirely. At the same time, the spring  5  exerts a second force  52  on the backrest  3 . The backrest  3  may be set in a locked position about the pivot axis  25 , because the second force action  52  locates the backrest  3  into a locked position, even if the backrest  3  was briefly set in an undefined or unlocked position. The second force action  52  occurs due to the positioning of the pivot axis  25 , and the positioning of a contact point of the spring  5  with the control surface  35 , and due to the torsional axis of the spring  5 . If an angle of greater than 90° is present, the load of the spring  5  generates the second force action  52  which drives the backrest  3  forward. 
     Referring back to  FIG. 3  the vehicle seat  1  is in a first seat position, with the backrest  3  pivoted or folder over toward the seat part  2 . In this position, the lever arm  55  of the spring  5  is fully released and the spring  5  is in a substantially fully relaxed, or non-preloaded, state. 
     Referring to  FIG. 4 , the vehicle seat  1  is located in a lowered position with respect to a floor  11  of the vehicle, also referred to as a second seat position  22 . The second seat position of the seat part  2  relative to the seat subassembly  10  of floor  11  is spaced a predetermined distance from the first seat position  21 . The first force action shown at  51  causes the spring  5  to drive the seat part  2  from its second seat position  22  to its first seat position  21 . Therefore, the first force action compensates for the body weight of a vehicle user sitting on the seat. 
     For example, the spring action and therefore the first and second force action  51 ,  52  of the spring  5  occurs since the rear tubular component  44  is rotatably and fixedly connected to the end of the spring  5  that is opposite the lever arm  55 . The rear tubular component  44  moves or rotates together with the rear links  42 . When setting the second seat position  22  of the seat part  2  from the first seat position  21 , a torque is exerted on the spring  5 , and i.e. a torque vector is directed outwardly. As a result of the positioning of the control surface  35 , the first force action  51  is exerted on the seat part  2 . 
     The system also includes a second energy storage mechanism, which in this example is a spring  6 , arranged on the front tubular component  43 . The second spring  6  constantly, regardless of the backrest position, exerts a third force as shown at  53 . The third force is parallel to the first force action  51  on the seat part  2 . 
     Referring to  FIGS. 5 to 10 , another example of an adjustable vehicle seat  1  is illustrated. In this example, the adjustment device  4  includes a plurality of rockers or links, with only the front link  41  and the rear link  42  being illustrated. The energy storage mechanism or spring  5  of this example is located between the front link  41  and the rear link  42  of the adjustment device  4 . A front articulation point of the spring  5  on the front link  41  is located closer to a center of rotation of the front link  41 , for example at the seat side, than the articulation point of the spring element  5  to a corresponding center of rotation of the rear link  42 . The force action of the spring  5  on the front link  41  takes place with a smaller lever arm, such that a predefined force action of the spring  5  leads to a smaller torque at the front link than at the rear link. The articulation point of the spring  5  on the front link  41  is denoted by the reference symbol A in  FIGS. 5 to 10 . 
     The spring may be connected to the rear link  42  using a first actuating lever  71  which may be freely rotatable with respect to the rear link  42 . The rotation of the first actuating lever  71  with respect to the rear link  42  may be limited by a stop  75 , such as a stop lug, in the clockwise rotational direction. The stop  75  or stop lug  75  is connected to the rear lever  42 . If the first actuating lever  71  is set such that it abuts against the stop lug, the force action resulting from the load state in the spring  5 , results in a torque exerted on the rear link  42  in a clockwise direction, so as to position the seat part  2  of the vehicle seat  1  in the upright position. The upright position of the backrest  3  is illustrated in  FIGS. 5 to 8 .  FIGS. 6 ,  7  and  8  illustrate the vehicle seat  1  in different height settings of the seat part  2  relative to the height shown in  FIG. 5  for the first seat position. The spring exerts a torque on the front link  41  and rear link  42 , such that the weight of the vehicle seat  1 , or the combined weight of the backrest  3 , the seat part  2  and a portion of the adjustment device  4 , is overcompensated for, such that the vehicle seat is set into a nominal seated position when it is empty, as illustrated in  FIG. 5 . 
       FIG. 5  also shows that the backrest  3  may also be pivotable about a pivot axis  25 , which may be below a center of rotation of the table folding function. In this example, the position of the first actuating lever  71  and of a second actuating lever  72  is varied so that the spring  5  no longer exerts a torque on at least the rear link  42 , because the first actuating lever  71  spaced apart from the stop  75 . 
     In  FIG. 9  the backrest  3  is folded partially forward. The arrangement of the pull rod  73  relative to the pivot axis  25  effectively rotates the first actuating lever  71  due to the movement of the second actuating lever  72 , such that the rear engagement point of the spring  5  is moved away from the stop  75  and can therefore no longer transmit torque to the rear link  42 . This occurs when the backrest  3  is folded completely forward, regardless of a position of the seat part, including height and incline as shown in  FIG. 10  by a spacing  76  between the stop  75  and the first actuating lever  71 . The first actuating lever  71 , the second actuating lever  72  and the pull rod are referred to as a control arrangement  7  which controls the exertion of torque by the spring  5  on the rear link  42 . In another example, the pull rod  73  may be replaced by a cable or the like. In addition, the first actuating lever  71 , also referred to as an intermediate lever, and the second actuating lever are integrally formed as one member. In this example, the control arrangement  7  includes both the first actuating lever  71  and also the second actuating lever  72 . A contact portion between the intermediate lever and the second actuating lever  72  is shown at  74 . If the pull rod  73  is pulled out of the position illustrated in  FIG. 5 , the second actuating lever  72  first rotates and, when the contact region  74  engages into the first actuating lever  71 , the first actuating lever  71  also rotates (counterclockwise in  FIG. 5 ), to form the space  76  between the first actuating lever with respect to the stop  75 . 
     In a further example of an adjustment device, the energy storage mechanism  5  is a gas pressure spring or as a telescopic gas spring  5 . The gas spring or telescopic gas spring  5  may be articulately connected to the front link  41 , as shown at A. The gas spring, operatively raises or equalizes only a portion of the seat weight, so that the vehicle seat  1  automatically lowers from any seat position set by the adjustment device  4 . An articulated connection of the spring  5  to the rear link  42  is provided with regard to the lever arm of the engagement point, with respect to the upper rotary bearing of the rear link  42  or lever arm  42 . Due to the force action of the spring  5 , the torque exerted is so large that the vehicle seat  1  is automatically pushed upward, or set in an upright position, from any seat position. Actuation of the control arrangement  7  by folding over the backrest  3  engages the spring  5  to create the space  76 . The spring  5  can no longer raise the vehicle seat at the rear link  42 , and the vehicle seat will lower downward in a braked or damped fashion as a result of the comparatively small lever arm of the spring  5  at the front link  41 , as shown at engagement point A. If the backrest  3  is set upright again, such as when the vehicle seat  1  is in a lowered second seat position, the control arrangement  7  is actuated in such a way that the starting position illustrated in  FIG. 5  is assumed. The spring  5 , at the stop  75 , exerts a torque on the rear lever  42  so as to raise the vehicle seat to the first seat position. 
     The present disclosure has been described as an illustrative manner. It is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. 
     Many modifications and variations of the present disclosure are possible in light of the above teachings. Therefore, the present disclosure may be practiced other than as specifically described.