Lumbar support mechanism for vehicle

A lumbar support mechanism for use with a seat comprising:

• a damper having one end supported by an inside of a backseat and the other end capable of extension and contraction;
• a left seesaw link having a distal end, an intermediate portion and a proximal end;
• a right seesaw link having a distal end, an intermediate portion and a proximal end;
• said proximal end of said left seesaw link being operatively connected to the proximal end of the right seesaw link and being capable of extension and contraction with the damper, the intermediate portion of the left seesaw link and the intermediate portion of the right seesaw link being supported at a swing fulcrum by the inside of the backseat, and the distal end of the left seesaw link and the distal end of the right seesaw link extending in a width direction of the backseat and swinging around the swing fulcrum;
• a left X-shaped pantograph link connected to the left seesaw link and being movable up and down in a back and forth direction in conjunction with the swing of the left seesaw link;
• a right X-shaped pantograph link connected to the right seesaw links and being movable up and down in a back and forth direction in conjunction with the swing of the right seesaw link;
• and
• a lock-release lever adapted to release a lock mechanism of the damper;
• wherein when the lock-release lever is manually operated to release the lock mechanism of the damper, the extension and contraction force of the damper is transmitted to the left and right X-shaped pantograph links via the corresponding left and right seesaw links, and the left and right X-shaped pantograph links shift a pad provided in the backseat in a back and forth direction.