Lumbar support

Abstract

The lumbar support for a seat backrest according to the invention has a lumbar pad and a toggle linkage to adjust the position of the lumbar pad. Furthermore, it comprises a motor with a spindle and a nut, wherein the motor rotates the spindle to move the nut along the spindle and wherein the nut is coupled to the toggle linkage, which includes an arm member which is pivotably connected to a frame and bears the lumbar pad and a link coupled to the nut and the arm member.

1 . Lumbar support for a seat backrest with a lumbar pad, a linkage to adjust the position of the lumbar pad and a motor with a spindle and a nut, wherein the motor rotates the spindle to move the nut along the spindle and wherein the nut is coupled to the linkage,
 characterized in that the linkage is a toggle linkage including an arm member which is pivotably connected to a frame and bears the lumbar pad and a link coupled to the nut and the arm member.   
   
   
       2 . Lumbar support according to  claim 1 , characterized by a frame for supporting the motor with the spindle and for providing a pivot point for the toggle linkage. 
   
   
       3 . Lumbar support according to  claim 1 , characterized in that the link is coupled to the arm member in a middle region between the connection of the arm member to the frame and the connection of the lumbar pad to the arm member. 
   
   
       4 . Lumbar support according to  claim 1 , characterized in that the spindle is pivotably fixed to the frame with one end and is connected to the arm member via the nut. 
   
   
       5 . Lumbar support according to  claim 1 , characterized in that toggle linkage has a scissor-type construction. 
   
   
       6 . Lumbar support according to  claim 1 , characterized by a control unit to move the lumbar pad by actuating the motor. 
   
   
       7 . Lumbar support according to  claim 4 , characterized in that control unit has a time setting device to set at time period for periodically activating the motor to move the nut in order to change the position of the lumbar pad.