Abstract:
A lumbar support of a car seat according to the present invention includes: a support plate to support user&#39;s back and made of elastic material; a support frame to which the support plate is rotatably engaged; a slider member mounted on the support frame in a movable manner in a vertical direction; a vertically driving means to move the slider member on the support frame; a biasing force control means including an upper member moving together with the slider member, a lower member disposed below the upper member, a biasing member connecting the upper and lower members to each other and having a controllable biasing force acting on the support plate depending on a distance between the upper and lower members, and an actuating means to control the distance between the upper member and the lower member.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a lumbar support of a car seat. 
     2. Description of the Related Art 
     In general, a car seat is to be provided so as to safely and comfortably support a passenger in the limited space of the vehicle room and in a limited range of weight. Therefore, the car seat includes a seat back having a seat back frame and a seat back pad so as to support the waist and back portions of a driver or a passenger, wherein the driver and a passenger who seat in the front seats can control the angles of the seat backs by pulling or pushing the same forwards or backwards according to the driving habit of the driver or the body conditions of the driver or the passenger. 
     However, there are difficulties to respond to the change of the seating posture of the driver or the passenger just by the seat back frame and the seat back pad in the case of long time driving. Therefore, a lumbar support is provided in the seat back so as to comfortably surround and support the back and the lumbar vertebra regions of the driver, wherein the lumbar support includes a support plate which comes in contact with the lumbar vertebra region of the driver and a controller for controlling the movement of the support plate. 
     PRIOR ART DOCUMENT 
     Patent Documents 
     
         
         Korean Reg. Patent Publication No. 10-1122980—Lumbar support of a car seat, registered on 24 Feb. 2012 
         Korean Reg. Patent Publication No. 10-1085154—Actuator system for controlling a lumbar support, registered on 14 Nov. 2011 
         Korean Reg. Patent Publication No. 10-0781018—Lumbar support system for a vehicle, registered on 23 Nov. 2007 
       
    
     SUMMARY OF THE INVENTION 
     In view of the prior art with respect to the lumbar support as above, a lumbar support as disclosed in Korean Reg. Patent Publication No. 10-1122980 comprises a pair of coupling means to be coupled to traversal fixing bars which are provided to the upper and lower portions in a seat back, a pair of support plates, each having a plurality of support wings provided at both right and left sides between the coupling means and the coupling means, a support member formed at the lower portions of the support plates and having a sacral region, and a support height control means for steplessly controlling the protruding height of the support plates which can selectively protrude to be curved at one side portion of each of the support plates, wherein a lumbar vertebra region is further provided to be integrated into the sacral region of the support member. 
     The prior art lumbar support as above can differ the bending degree of the support plate by manually operating a rotary lever which is mounted on the side wall portion of the seat. However, for the promotion of the convenience of a driver, the bending degree control by any other method rather than the inconvenient manual operation of the rotary lever has been required. 
     As a prior art for resolving the inconvenience of the manual operation and providing automatic controlling of the lumbar support, Korean Reg. Patent Publication No. 10-1085154 discloses a technique, wherein a deceleration part includes a worm, a worm gear and a screw so as to connect a wire of which one end is fixed to a lumbar support to a driving motor such that a slider which is screw-coupled to the screw moves in a housing by the operation of the deceleration part so as to pull or push the wire, thereby controlling the bending degree of support plates. 
     However, the prior art as above still has a problem that the wire snaps due to the load which is continuously applied thereto even though the bending degree can be controlled using the wire which is fixed at the upper and lower portions of the support plates. 
     The present invention is derived in consideration of the problems and disadvantages of the prior art and has an objective to provide a lumbar support of a car seat, of which bending degree can be automatically controlled by power while stably pressing support plates so as to improve the safety of the product. 
     In order to achieve the above and any other objectives of the present invention, provided is a lumbar support of a car seat, comprising: support plates made from a synthetic resin material in the shape of a plate and having a plurality of support wings at both sides and fixing hooks on top of the rear surface thereof; support frame positioned at the rear portions of the support plates and having a support rod engaged with the fixing hooks and a pair of guide rods connected to the support rod in parallel to each other; slider member provided to move in the vertical direction by the guide of the guide rods and having a spiral hole formed in the center thereof; vertically driving means having a driving motor driven by an external input signal and a screw which is coupled in the spiral hole of the slider member so as to move the slider member by the operation of the driving motor; and a biasing force control means positioned between the support plates and the support frame and controlling the pressing degree of the support plates according to the operation of a user, wherein the biasing force control means includes; an upper member coupled to the slider member; a lower member guided to move in contact with the guide rods of the support frame; and coil springs having both end portions which are respectively fitted and fixed into the upper member and the lower member and a shaft fitted into a coil portion in the center thereof; wherein a wire which passes through an insertion hole of the lower member so as to be held by the upper member is pulled and released by an actuator such that the central coil portion of the coil springs presses the support plates. 
     According to another aspect of the present invention, the rollers may be mounted on the shaft by being fitted between the coil springs at both sides of the shaft. 
     Further, hinge parts may be formed at both end portions of the slider member so as to surround the hinge shafts which are formed at both ends of the upper member, and guide protrusions may be respectively formed by protruding from the both sides of the lower member so as to prevent the movement of the lower member in the right and left directions when the lower member moves in the vertical direction along the guide of the guide rods. 
     According to another aspect of the present invention, provided is a lumbar support of a car seat comprising: a support plate to support user&#39;s back and made of elastic material; a support frame to which the support plate is rotatably engaged; a slider member mounted on the support frame in a movable manner in a vertical direction; a vertically driving means to move the slider member on the support frame; a biasing force control means including an upper member moving together with the slider member, a lower member disposed below the upper member, a biasing member connecting the upper and lower members to each other and having a controllable biasing force acting on the support plate depending on a distance between the upper and lower members, and an actuating means to control the distance between the upper member and the lower member. 
     Here, fixing hooks may be formed in one end of the support plate which is hingedly engaged to the support frame. 
     Further, the support frame may include: a supporting member to which the fixing hooks are engaged; and a pair of guides rod fixed to the supporting member. 
     Further, the slider member may be guided by a pair of guide rods provided to the support frame, and the vertically driving means is fixed to the support frame. 
     Here, the vertically driving means may include: a driving motor; a screw driven by the driving motor and engaged with the slider member via a threaded hole formed in the slider member. 
     Further, each end of the biasing member may be respectively engaged to the upper member and the lower member. 
     Here, the biasing member may be configured to be protruded toward the support plate as the distance between the upper member and the lower member decreases. 
     Here, the biasing member may include: coil springs extended between the upper member and the lower member; and a shaft inserted into the coil springs. 
     Here, the biasing member may include a pair of coil springs and the shaft inserted into both of the pair of coil springs. 
     Here, the actuating means may include: a wire engaged to the upper member through the lower member; and an actuator pulling or releasing the wire such that the central coil portion of the coil springs presses the support plate. 
     According to the present invention in the above structure, the central coil portion presses the support plates by coming in or out by the operation for decreasing or increasing a distance between the upper member  50  and the lower member  60  which are coupled to the both ends of the coil springs  70 . Therefore, the pressing operation can be smoothly carried out. 
     Further, the pressing portion which comes in contact with the support plates is pressed in the coil portion which is positioned in the center of the coil springs  70 . Therefore, the support plates which supports a human body is applied with elasticity even in the case of collisions or the like during driving. Therefore, it is possible to more safely protect a driver. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing the entire configuration of a lumbar support according to an embodiment of the present invention. 
         FIG. 2  is a front view of the lumbar support of  FIG. 1 . 
         FIG. 3  is a plane view of the lumbar support of  FIG. 1 . 
         FIG. 4  is a perspective view showing the principal construction of a pressing device which presses support plates according to the present invention. 
         FIG. 5  is a rear view showing the principal construction of the pressing device according to the present invention. 
         FIG. 6  is a side view showing a state before that the support plates are pressed according to the present invention, and 
         FIG. 7  is a side view showing a state after that the support plates are pressed according to the present invention. 
     
    
    
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 Brief Description of Reference Numerals 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 10 - support plate 
                 12 - support wings 
               
               
                   
                 20 - support frame 
                 22 - guide rods 
               
               
                   
                 30 - slider member 
                 31 - spiral hole 
               
               
                   
                 32 - hinge parts 
                 40 - vertically driving means 
               
               
                   
                 41 - driving motor 
                 42 - screw 
               
               
                   
                 50 - upper member 
                 51 - hinge shafts 
               
               
                   
                 60 - lower member 
                 61 - guide protrusions 
               
               
                   
                 70 - coil springs 
                 72 - shaft 
               
               
                   
                 80 - actuator 
                 81 - wire 
               
               
                   
                   
               
             
          
         
       
     
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, the present invention will be described in greater detail by reference to the drawings. However, the present invention should not be construed as being limited thereto. 
     Now, the configuration of the present invention to achieve the above objective will be described. 
     According to the present invention, a lumbar support of a car seat is provided in a seat back and controlled to move forwards or backwards with respect to the lumbar vertebra region of a passenger by power so as to support the lumbar vertebra region of a passenger such that the contact and comfort of a passenger in a seat can be improved and an overload is prevented from being applied to the lumbar region of the passenger due to the improper seating posture of the passenger. 
     A lumbar support according to the present invention mainly includes support plates  10  in the shape of a general plate, a support frame  20  formed of a support rod  21  and a pair of guide rods  22  which are in parallel to each other and connected to the support rod  21 , a slider member  30  provided so as to move in the vertical direction by the guide of the guide rods  22 , a vertically driving means  40  for reciprocatingly moving the slider member  30 , and a biasing force control means for controlling the degree to press the support plates  10  by the operation of a user. 
     The support plates  10  is, as shown in  FIG. 1 , made from a synthetic resin material which has excellent elasticity and provided with a plurality of support wings  12  at both sides, wherein fixing hooks  13  in the shape of a hook are formed at the upper portion of the rear surface thereof. 
     The support plates  10  as above have through holes penetrated in the shape of a rectangle in the center and both side portions. The support wings  12  provided at both sides of the support plates  10  are formed to be slightly larger than the support wings  12  provided in the center of the support plates  10 . The support wings  12  are provided at an interval so as to increase the elasticity. 
     Further, the fixing hooks  13  which are formed at the upper portions of the rear surface are formed in the shape of a hook such that the fixing hooks  13  are prevented from being separated from the horizontal support rod  21  of the support frame  20  in the state that the fixing hooks  13  are fitted on the horizontal support rod  21  of the support frame  20  as described below. 
     The support frame  20  is formed by folding a metal rod and coupled to the rear surface of the support plates  10 , and has the support rod  21  which horizontally extends at the upper portion thereof and the guide rods  22  which are in parallel to each other and connected to the support rod  21  in the vertical direction. 
     The slider member  30  has a spiral hole  31  formed in the center of the body part thereof and is provided to be slidable along the guide of the guide rods  22  in the state that the slider member  30  is screw-coupled to the screw  42  of the vertically driving means  40 . 
     As for the operations of the slider member  30 , the screw  42  rotates by the driving motor  41  which rotates in the clockwise direction or the counterclockwise direction according to a signal by the selection of a user such that the slider member  30  carries out sliding motion in the vertical direction according to the rotation direction of the driving motor  41 . 
     Meanwhile, the vertically driving means  40  preferably includes a worm gear  43  and a worm gear  44  which are engaged with each other and provided to the screw  42  of the driving motor  41  so as to obtain a deceleration ratio as desired. 
     Further, the vertically driving means  40  is provided with a hall sensor (not shown) for sensing the rotation number of the driving shaft of the driving motor  41  and a motor control circuit for stopping the operation of the driving motor  41  as the rotation number of the driving shaft of the driving motor  41  reaches a preset rotation number. 
     In addition, the biasing force control means is positioned between the support plates  10  and the support frame  20  so as to control the degree to press the support plates  10  by the operation of the user. 
     The biasing force control means according to the present invention includes an upper member  50  which is hinge-coupled to the slider member  30 , a lower member  60  which is guided to move in contact with the guide rods  22  of the support frame  20 , coil springs  70  which are fixed to the upper member  50  and the lower member  60  by respectively fitting the both end portions into the upper member  50  and the lower member  60 , a shaft  72  which is inserted into the coil portions of the coil springs  70 , and an actuator  80 , wherein a wire  81  which is held by the upper member  50  by passing through an insertion hole  42   a  of the lower member  60  is pulled or released such that the coil portions in the center of the coil springs press the support plates  10 . 
     At this time, rollers  73  are fitted between the coil springs  70  at both sides of the shaft  72  so as to reduce the frictional resistance when the support plates  10  are pressed. 
     The operations of the biasing force control means according to the present invention structured as above will now be described in reference with  FIG. 4  to  FIG. 7 . 
     First, a user who seats in the driver&#39;s seat or the passenger&#39;s seat operates an operation part (not shown) for the control of the lumbar support, an operation signal is transmitted to a controller (not shown) such that power is supplied to the driving motor  41  via the controller. 
     As the screw  42  rotates by the power of the driving motor  41 , the slider member  30  which is coupled to the spiral hole  31  lifts or lowers in the vertical direction by the screw  42 . 
     At this time, the slider member  30  is hinge-coupled to the upper member  50  and the upper member  50  is connected to the lower member  60  through the one pair of coil springs, such that the above constituent elements move together in the vertical direction. 
     In this way, the pressing position of the support plates  10  can be controlled in the vertical direction. 
     Further, the degree for pressing the support plates  10  is determined by the biasing force control means. 
     As the user manipulates a switch in order to operate the biasing force control means in the case of automatic power control, the actuator  80  pulls or releases the wire  81 . 
     In addition, the wire  81  can be pulled or released if the user rotates a lever in a desired direction in the case of manual control. 
     The end portion  81  of the wire  81  is held by a holding hook  82  on the upper member  50  which is hinge-coupled to the slider member  30 . 
     Hinge parts  32  are formed at both end portions of the slider member  30  so as to surround the hinge shafts  51  which are formed at both ends of the upper member  50 . 
     Therefore, the slider member  30  is placed in position in the state that the slider member  30  and the upper member  50  are lifted or lowered together, and the upper member  50  can rotate at an inclination together with the coil springs  70  with respect to the hinge shafts  51  as shown in  FIG. 7 . 
     Further, the both end portions  71  of the coil springs  70  are fitted between the upper member  50  and the lower member  60 . Therefore, the distance between the upper member  50  and the lower member  60  decreases as the wire  81  is pulled such that the coil portions which are positioned in the centers of the coil springs  70  protrude forwards and press the support plates  10 . 
     Therefore, a press part which comes in contact with the support plates is supported by the coil springs  70  so as to maintain the elasticity of the springs. Thus, the support plates which support the body of the driver can be applied with elasticity and absorb shocks so as to more safely protect the driver even in the case of a collision during driving. 
     At this time, the coil springs  70  have elasticity such that the both end portions  71  of the coil springs  70  are maintained in a straight line in the free state of the coil springs  70  and the coil springs  70  are restored to the straight line state if tension is applied thereto while the center coil portions protrude forwards by the wire  81 . 
     At this time, it is preferable to provide the rollers  73  between the coil springs  70  at both sides of the shaft  72  by fitting so as to reduce the frictional resistance which is applied when the support plates  10  are pressed. 
     Further, it is preferable to respectively provide guide protrusions  61  at both sides of the lower member  60  so as to prevent the lateral movement of the lower member  60  when the lower member  60  moves along the guide rods  22  in the vertical direction. 
     If the user operates the actuator  80  so as to release the wire  81 , the support plates which have protruded towards the lumbar vertebra region are restored as shown in  FIG. 6 , and the pressing degree can be controlled by stopping the operation at a desired position. 
     Therefore, the lumbar support according to the present invention can stably and comfortably support the protruding motion of the support plates  10  and absorb the shock at the time of a vehicle collision, thereby safely protecting the driver. 
     The embodiments described above are to be understood as a few illustrative examples of the present invention and the invention is not to be limited by any of the embodiments and drawings of the description. It will be understood by those skilled in the art that various modifications, combinations and changes may be made to the embodiments without departing from the scope of the present invention.