A seat, which provides an enhanced level of comfort, by the use of dual
independently supported seat cushions is disclosed. The apparatus
comprises an inner seat cushion and an outer seat cushion, each of which
is independently supported by a compressed air pneumatic device to
control vertical movement, and by parallelogram linkages control lateral
movement, and allow for vertical transition of the seats while
maintaining them horizontal. The occupant of this seat can independently
adjust the distribution of body weight shared by the inner seat cushion
and the outer seat cushion from time to time, in order to change the
pressure pattern against body parts and to provide optimum ergonomic
seating posture. Furthermore, by adjusting the air supply, the occupant
can increase or decrease the seat's effective spring rate.