Patent ID: 7967382

Claim:
A side bolster apparatus for a foldable seat back, the side bolster apparatus comprising: a pressing unit formed in a lower portion of the seat back so as to provide an external force generated by rotating the seat back; a bolster configured to protrude forwards from a rear side of the seat back; and an external force transmitting unit connected to the pressing unit and receiving the external force from the pressing unit when the seat back is unfolded and transmitting the received external force to the bolster such that the bolster protrudes from the seat back, wherein the bolster has a predetermined curvature in a longitudinal direction of the seat back; wherein the external force transmitting unit includes: an elevator raising or lowering the bolster with respect to the seat back; a direction converter slidably coupled to the seat back and moving in substantially perpendicular direction to a movement direction of the elevator, wherein the direction converter has a slope so as to provide the external force to the elevator; and a cable, wherein one end thereof is connected to the direction converter and the other end thereof is connected to the pressing unit; and wherein the elevator includes: a stationary guide fixed to the seat back such that the direction converter is displaceable thereto, wherein the stationary guide has a slit formed on one lateral side thereof in a direction where the bolster is raised or lowered; and a movable guide slidably coupled to the stationary guide, one end of which is connected with the bolster and the other end of which includes a guide knob fitted into the slit of the stationary guide to move therein, the movable guide raised or lowered by the slope of the direction converter.