.~.~ Back tilts while seat inclination adjusts {4}
300.4
.~.~.~ Torsion bar or torsion spring
DEFINITION
Classification: 297/300.4
Torsion bar or torsion spring:
(under subclass 300.2) Simultaneously adjusted back and seat wherein the resilient member is a solid material considerably longer than it is wide, or is a corkscrew-type that twists to resist the tilting of the back.