UNDERFRAME FOR A HEIGHT ADJUSTER, AND HEIGHT ADJUSTER

An underframe for a height adjuster of a seat, in particular a vehicle seat, may have a base frame which is connectable to a vehicle floor, a seat frame which is adjustable relative to the base frame and has at least one frame part, and a spindle drive unit for adjusting the seat frame relative to the base frame. The spindle drive unit has a first bearing point, which is connected pivotably to the frame part, and a second bearing point, which is connected pivotably to the base frame. A height adjuster for the vehicle seat is also provided.