Transmission amplifier assembly for a bowden cable and method of using the same

Abstract

A bowden cable transmission device ( 10′ ) is provided between the bowden cable actuator ( 16 ) and the lumbar support member ( 14 ) of an adjustable lumbar support assembly ( 12 ). The bowden cable transmission device converts movement of a first wire portion ( 52 ) of a bowden cable ( 18 ) attached to the bowden cable actuator ( 16 ) into movement of a second wire portion ( 26 ) attached to the lumbar support member ( 14 ) in accordance with a predetermined transmission ratio such that a movement or adjustment of the second wire portion ( 26 ) is facilitated.

1 . An adjustable lumbar support assembly, comprising: 
 an adjustable lumbar support member;    a Bowden cable actuator for actuating a Bowden cable having a first wire portion and a second wire portion; and    a transmission amplifier assembly for the Bowden cable, the transmission amplifier assembly comprising a rotary member being supported rotatably, the Bowden cable with the first wire portion being connected between the Bowden cable actuator and the transmission amplifier assembly and with the second wire portion being connected between the transmission amplifier assembly and the adjustable lumbar support member, and the first wire portion and the second wire portion of the Bowden cable being both coupled to the rotary member such that movement of the first wire portion imparts rotation of the rotary member and thereby movement of the second wire portion in accordance with a predetermined transmission ratio, the movement of the second wire portion being facilitated compared to the movement of the first wire portion by the predetermined transmission ratio.    
   
   
       2 . The adjustable lumbar support assembly according to  claim 1 , wherein the transmission amplifier assembly is arranged such that the movement of the first wire portion imparts the movement of the second wire portion, which is increased by the predetermined transmission ratio with respect to the movement of the first wire portion.  
   
   
       3 . The adjustable lumbar support assembly according to  claim 1 , wherein the first wire portion and second wire portion both are directly fixed at the rotary member.  
   
   
       4 . The adjustable lumbar support assembly according to  claim 1 , wherein the first wire portion and the second wire portion extend both along a periphery of the rotary member.  
   
   
       5 . The adjustable lumbar support assembly according to  claim 4 , wherein the first wire portion and the second wire portion extend both along respective grooves formed in the periphery of the rotary member.  
   
   
       6 . The adjustable lumbar support assembly according to  claim 1 , wherein the rotary member has a substantially longitudinal shape.  
   
   
       7 . The adjustable lumbar support assembly according to  claim 6 , wherein the rotary member has a substantially elliptic shape.  
   
   
       8 . The adjustable lumbar support assembly according to  claim 1 , wherein the rotary member has a substantially increasing width from a portion of the rotary member where the first wire portion leaves the periphery of the rotary member to a portion of the rotary member where the second wire portion leaves the periphery of the rotary member.  
   
   
       9 . The adjustable lumbar support assembly according to  claim 1 , wherein the rotary member is supported rotatable around a point of rotation, the point of rotation being arranged eccentrically in a longitudinal direction of the rotary member.  
   
   
       10 . The adjustable lumbar support assembly according to  claim 1 , wherein the first wire portion and the second wire portion are formed by a single wire movable in the sleeve of the Bowden cable.  
   
   
       11 . The adjustable lumbar support assembly according to  claim 1 , wherein the sleeve of the Bowden cable is held in place by a holding member.  
   
   
       12 . The adjustable lumbar support assembly according to  claim 1 , wherein a guiding member for guiding the first wire portion towards the rotary member and a guiding member for guiding the second wire portion from the rotary member are provided.  
   
   
       13 . The adjustable lumbar support assembly according to  claim 12 , wherein the guiding member for the first wire portion and the guiding member for the second wire portion are formed by a common guiding member.  
   
   
       14 . The adjustable lumbar support assembly according to  claim 1 , wherein the transmission amplifier assembly is arranged such that a lever arm defined between the second wire portion and a point of rotation of the rotary member is larger than a lever arm defined between the first wire portion and the point of rotation by a predetermined transmission ration.  
   
   
       15 . The adjustable lumbar support assembly according to  claim 1 , wherein the transmission amplifier assembly is attached to the adjustable lumbar support member.  
   
   
       16 . A method of adjusting a lumbar support member, comprising the steps: 
 causing motion of a first wire portion of a Bowden cable relative to a sleeve of the Bowden cable via a Bowden cable actuator; 
 converting the motion of the first wire portion into motion of a second wire portion in accordance with a predetermined transmission ratio, the conversion being such that the motion of the second wire portion being facilitated compared to the motion of the first wire portion by the predetermined transmission ratio; 
 adjusting the lumbar support member in response to the motion of the second wire portion.  
 
   
   
   
       17 . The method according to  claim 16 , wherein the motion of the first wire portion is converted into the motion of the second wire portion using said transmission amplifier assembly.