Abstract:
An apparatus for tilting a vehicle seat cushion raises the front end to be higher than the rear end of the seat cushion in order to enhance a supporting force for an occupant seated in a vehicle seat, thereby preventing the occupant from being pushed forwards in the event of sudden braking. The apparatus includes a cushion tilting unit installed in the seat cushion, wherein the cushion tilting unit raises a front end of a seat cushion to be higher than a rear end of the seat cushion without adjusting an angle of the seat back.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims the priority of Korean Patent Application No. 10-2008-0075218 filed Jul. 31, 2008, the entire contents of which applications is incorporated herein for all purposes by this reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to an apparatus for tilting a vehicle seat cushion, and more particularly, to an apparatus for tilting a vehicle seat cushion, which can raise the front end to be higher than the rear end of the seat cushion in order to enhance a supporting force for an occupant accommodated in a vehicle seat, thereby preventing the occupant from being pushed forwards in the event of sudden braking. 
         [0004]    2. Description of Related Art 
         [0005]    A vehicle seat generally includes a seat cushion fixed to a vehicle body to accommodate an occupant and a seat back rotatably mounted to the seat cushion to act as the back of the seat. 
         [0006]      FIG. 1  is a perspective view illustrating skeletal frames of a seat cushion and a seat back of a conventional vehicle seat, and  FIGS. 2A and 2B  are reference views illustrating a variation in the slope of a conventional seat cushion, which takes place when the height of the seat cushion is adjusted. 
         [0007]    As shown in  FIG. 1 , a vehicle seat  10  includes a seat cushion  11  for accommodating an occupant, a seat back  12  pivotally connected to a rear end of the seat cushion  11 , and a reclining part  13  for angularly rotating the seat back  12  with respect to the seat cushion  11 . 
         [0008]    In convenience, in  FIG. 1 , only the frames of the seat cushion  11  and the seat back  12  are shown with the exterior fabrics removed therefrom in order to explain in detail the interconnecting relationship between the seat cushion  11  and the seat back  12 . 
         [0009]    The reclining part  13  of the vehicle seat  10  makes it possible to adjust the angle of the seat back  12  with respect to the seat cushion  11  so that an occupant can be comfortably accommodated in the vehicle seat  10 . 
         [0010]    The seat cushion  11  is also adjustable in height so that occupants having different body sizes and postures can adjust the height of the seat cushion  11  to a position to make them comfortable. As shown in  FIGS. 2A and 2B , the height of the seat cushion  11  can be adjusted to be comfortable to the respective occupants. 
         [0011]    However, when the height of the conventional vehicle seat cushion  11  is adjusted using a height adjusting mechanism equipped therein, the seat cushion  11  is inclined with the front end thereof set lower than the rear end thereof, as shown in  FIGS. 2A and 2B , due to the structural features of the seat cushion  11 . 
         [0012]    In the inclined seat cushion  11 , thighs of the occupant cannot come into close contact with the seat because of an insufficient amount of supporting force, and the occupant is apt to slip from the seat cushion  11 . This subsequently causes a very risky situation in which the body of the occupant will be pushed forwards in the event of sudden braking. 
         [0013]    While the construction illustrated in  FIGS. 1-2B  is a manual frame construction in which the height of the seat cushion is manually adjusted, the same problems take place in a power frame construction in which the height of the seat cushion is automatically adjusted. To overcome this problem, a conventional power frame type seat cushion adopted an additional device, which can raise the front end of the seat cushion to a predetermined height. However, this device causes to rotate the entire seat backwards around the rear end of the seat cushion. The seat back is also pulled back, thereby causing a problem in that the occupant has to adjust the angle of the seat back again by rotating the seat back forwards after the front end of the seat cushion was raised. 
         [0014]    The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art. 
       BRIEF SUMMARY OF THE INVENTION 
       [0015]    Various aspects of the present invention provide an apparatus for tilting a vehicle seat cushion, which can raise the front end to be higher than the rear end of the seat cushion in order to enhance a supporting force for an occupant seated in a vehicle seat, thereby preventing the occupant from being pushed forwards in the event of sudden braking. 
         [0016]    An aspect of the present invention is directed to an apparatus for tilting a seat cushion of a vehicle seat, which may include the seat cushion and a seat back pivotally mounted to the seat cushion. The apparatus may include a cushion tilting unit installed in the seat cushion, wherein the cushion tilting unit raises a front end of the seat cushion to be higher than a rear end of the seat cushion without adjusting an angle of the seat back. 
         [0017]    The cushion tilting unit may include a tilting part placed in the front end of the seat cushion, wherein an rear end of the tilting part may be hinged to a place positioned beyond a front end of a cushion frame of the seat cushion in a rear direction so as to allow a front end of the tilting part to rotate with respect to the rear end of the tilting part, a cross bar coupling the front end of the cushion frame and the front end of the tilting part via a hinge arm and having a predetermined radius of rotation with respect to the front end of the cushion frame so as to lift the front end of the tilting part in a predetermined range of rotation, an external force transmission for applying an external force to the cross bar, and/or an external force generator for supplying the external force to the external force transmission. 
         [0018]    The cushion tilting unit further may include a holder displaced on a lower surface of the tilting part and a receiving slot, the holder limiting a movement of the cross bar via the receiving slot. The external force transmission may include a vertical transmission part pivotally connected to the cross bar, and/or a horizontal transmission part pivotally linked to the vertical transmission part and connected to the external force generator. The external force generator may include a drive motor. The external force generator may include an operation lever. The external force generator may be attached to the cushion frame. 
         [0019]    The cushion tilting unit may include a tilting part placed in the front end of the seat cushion, wherein an rear end of the tilting part may be hinged to a place positioned beyond a front end of a cushion frame of the seat cushion in a rear direction so as to allow a front end of the tilting part to rotate with respect to the rear end of the tilting part, a cross bar coupling the front end of the cushion frame and the front end of the tilting part via a hinge arm so as to lift the front end of the tilting, an external force transmission for applying an external force to the cross bar, and/or an external force generator for supplying the external force to the external force transmission. The external force transmission may include a vertical transmission part pivotally connected to the cross bar, and/or a horizontal transmission part pivotally linked to the vertical transmission part and connected to the external force generator. The external force generator may include a drive motor. The external force generator may include an operation lever. The external force generator may be attached to the cushion frame. 
         [0020]    Another aspect of the present invention is directed to an apparatus for tilting a seat cushion of a vehicle seat, which may include the seat cushion and a seat back pivotally mounted to the seat cushion. The apparatus may include a cushion tilting unit installed in the seat cushion, wherein the cushion tilting unit raises a front end of the seat cushion to be higher than a rear end of the seat cushion without adjusting an angle of the seat back. The cushion tilting unit may further include a tilting part placed in the front end of the seat cushion, wherein an rear end of the tilting part may be hinged to a place positioned beyond a front end of a cushion frame of the seat cushion in a rear direction so as to allow a front end of the tilting part to rotate with respect to the rear end of the tilting part, a cross bar coupling the front end of the cushion frame and the front end of the tilting part via a hinge arm and having a predetermined radius of rotation with respect to the front end of the cushion frame so as to lift the front end of the tilting part in a predetermined range of rotation, an external force transmission for applying an external force to the cross bar, and/or an external force generator for supplying the external force to the external force transmission. 
         [0021]    A further aspect of the present invention is directed to an apparatus for tilting a seat cushion of a vehicle seat, which may include the seat cushion and a seat back pivotally mounted to the seat cushion, including a cushion tilting unit installed in the seat cushion, wherein the cushion tilting unit raises a front end of the seat cushion to be higher than a rear end of the seat cushion without adjusting an angle of the seat back. The cushion tilting unit may further include a tilting part placed in the front end of the seat cushion, wherein an rear end of the tilting part may be hinged to a place positioned beyond a front end of a cushion frame of the seat cushion in a rear direction so as to allow a front end of the tilting part to rotate with respect to the rear end of the tilting part, a cross bar coupling the front end of the cushion frame and the front end of the tilting part via a hinge arm so as to lift the front end of the tilting part, an external force transmission for applying an external force to the cross bar, and/or an external force generator for supplying the external force to the external force transmission. 
         [0022]    A still further aspect of the present invention is directed to a system for tilting a seat cushion of a vehicle seat, which may include the seat cushion and a seat back pivotally mounted to the seat cushion. The system may include any of the above-described apparatus for tilting the seat cushion of the vehicle seat. Similarly, a passenger vehicle may include any of the above-described apparatus for tilting the seat cushion of the vehicle seat. 
         [0023]    According to an aspect of the present invention, the front end of the seat cushion may be tilted without causing to change the angle of the seat back. This as a result can improve the ease and convenience of use of the seat as well as enhance a supporting force for the occupant accommodated in the seat, thereby preventing the occupant from being pushed forwards in the event of sudden braking. 
         [0024]    Moreover, the apparatus for tilting a seat cushion of the present invention can be very easily applied to various seats in practice since it is applicable to a variety of frame constructions including a power frame and a manual frame. 
         [0025]    The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  is a perspective view illustrating skeletal frames of a seat cushion and a seat back of a conventional vehicle seat. 
           [0027]      FIGS. 2A and 2B  are reference views illustrating a variation in the slope of a conventional seat cushion, which takes place when the height of the seat cushion is adjusted. 
           [0028]      FIG. 3  is a perspective view illustrating an exemplary vehicle seat according to the present invention. 
           [0029]      FIG. 4  is a perspective view illustrating an exemplary apparatus for tilting a vehicle seat cushion according to the present invention, which is in a state before tilting. 
           [0030]      FIG. 5  is a perspective view illustrating an exemplary apparatus for tilting a vehicle seat cushion according to the present invention, which is in a state after tilting. 
           [0031]      FIGS. 6A and 6B  are side elevational views of the tilting apparatus of  FIGS. 4 and 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0032]    Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. 
         [0033]      FIG. 3  is a perspective view illustrating an exemplary vehicle seat according to the present invention,  FIG. 4  is a perspective view illustrating an exemplary apparatus for tilting a vehicle seat cushion according to the present invention, which is in a state before tilting,  FIG. 5  is a perspective view illustrating an exemplary apparatus for tilting a vehicle seat cushion according to the present invention, which is in a state after tilting, and  FIGS. 6A and 6B  are side elevational view of  FIGS. 4 and 5 . 
         [0034]    Referring to  FIGS. 3-5 , in a vehicle seat including a seat back  110  and a seat cushion  120 , the apparatus for tilting a vehicle seat cushion in various embodiments of the present invention includes a cushion tilting unit  200  installed in a portion of the seat cushion  120 . The cushion tilting unit  200  is configured to raise the front end of the seat cushion  120  to be higher than the rear end of the seat cushion  120  without adjusting the angle of the seat back  110 . 
         [0035]    As detailed in  FIGS. 4 and 5 , the cushion tilting unit  200  generally includes a tilting part  210 , a cross bar  220 , an external force transmission  230  and an external force generator  240 . 
         [0036]    The tilting part  210  is placed in the front part of the seat cushion  120  and is pivotally connected to a rear end of a cushion frame  121  of the seat cushion  120 . In detail, the rear end of the tilting part  210  is hinged to the rear end of the cushion frame  121  so that the front end of the tiling part  210  can rotate upwards with respect to the rear end of the cushion frame  121 . 
         [0037]    When the front end of the tilting part  210  rotates upwards, the tilting part  210  raises the seat cushion  120  loaded thereon so that the front end of the seat cushion  120  becomes higher than the rear end thereof. 
         [0038]    The cross bar  220  is installed under the front end of the tilting part  210  to extend in the width direction of the seat. The cross bar  220  is hinged to a front end of the cushion frame  121  via a hinge arm  221  so as to rotate with respect to the cushion frame  121 . Here, the front end of the tilting part  210  can be lifted up by rotation of the cross bar  220 . 
         [0039]    When an external force is applied with a predetermined amount to allow raising the tilting part  210 , the cross bar  220  rotates and raises the tilting part  210 , which in turn raises the front end of the seat cushion  120 . 
         [0040]    In various embodiments of the present invention, it may be preferable that holders  250 , which limit the movement of the cross bar  220 , be installed on the lower surface of the tilting part  210 , as shown in the drawings. The cross bar  220  can transmit the external force to the tilting part  210  without the holders  250 . However, if the angle of rotation of the cross bar  220  is excessively large, the cross bar  220  may rotate further beyond the upper dead point so that the tilting part  210  will descend again after reached the highest level. It is therefore preferable that the angle of rotation of the cross bar  220  is limited to such a degree that the tilting part  210  can stop at the highest level in various embodiments. 
         [0041]    Accordingly, the holders  250  function to limit the angle of rotation of the cross bar  220  so that the tilting part  210  can stop at the highest level and to prevent the cross bar  220  not to be spaced far apart from the tilting part  210  when an external force is not applied. 
         [0042]    The external force transmission  230  is constructed to transmit the external force from the external force generator  240  to the cross bar  220 , which can rotate under the applied external force. 
         [0043]    The external force transmission  230  may be configured as a linear rod if the external force generator  240  having a vertical arrangement is disposed below the cross bar  220 . As shown in  FIGS. 4 and 5 , when the external force generator  240  having a horizontal arrangement is disposed on a cushion frame  121 , the external force is transmitted in two directions, i.e., a horizontal direction and a vertical direction. 
         [0044]    For this, the external force transmission  230  includes a vertical transmission part  231  hingedly connected to the cross bar  220  and a horizontal transmission part  232  pivotally linked to the vertical transmission part  231 . The horizontal transmission part  232  is also connected to the external force generator  240 . 
         [0045]    Due to this construction, an external force from the external force generator  240  will be applied to the horizontal transmission part  232 , which in turn will rotatably push the vertical transmission part  231 , which will finally raise the cross bar  220  to rotate pivotally. 
         [0046]    As shown in  FIGS. 4 and 5 , the external force generator  240  can be implemented with a drive motor. In this case, a control switch for operating the drive motor may also be installed around the cushion frame  121 . 
         [0047]    When the control switch is operated, the drive motor rotates forwards or backwards to lift up or down the frond end of the tilting part  210 . The external force generator  240  implemented with the drive motor as described above can be employed in a conventional power frame construction. 
         [0048]    The external force generator  240  may be implemented with an operation lever. The operation lever is installed around the cushion frame  121  so that a user can manually push or pull the operation lever to lift up or down the tilting part  210 . The external force generator  240  implemented with the operation lever can be employed in a conventional manual frame construction. 
         [0049]    The apparatus for tilting a seat cushion according to the present invention can be applied to both the power frame construction and the manual frame construction, which are well known per se in the art. Since the apparatus for tilting a seat cushion of the present invention can cause to easily lift up or down the front end of the seat cushion while keeping the original shape of a frame construction of an existing vehicle seat, its applicability is very high. 
         [0050]    Due to the cooperative operation of the external force generator  240 , the external force transmission  230  and the cross bar  220  as described above, the front end of the tilting part  210  can be lifted up or down around the hinge, mounted on the rear end of the tilting part  210 , as shown in  FIGS. 6A and 6B . Accordingly, a supporting force for an occupant accommodated in the seat is greatly increased. Furthermore, the ease and convenience of use is ensured since it is not required to adjust the angle of the seat back  110  when the seat cushion  120  is tilted. 
         [0051]    For convenience in explanation and accurate definition in the appended claims, the terms “upper” or “lower”, “front” or “rear”, and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. 
         [0052]    The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.