A thermal printer, including a drive platen, which has its external dimensions reduced to a level suitable for use in connection with portable information apparatuses. The microprocessor-based control system of the present invention dispenses with the need to utilize relays, timers, or other control hardware. In an illustrated embodiment, the power plant device is a soot cleaning device associated with a boiler. Rotation of the inner bolt causes the upper and lower portions of the outer sleeve to separate, causing the pedicle cut to widen and the expandable flanges to radially extend into and stabilize the widened pedicle cut to effectuate expansion of the spinal canal. The outer ends of said diametric arms are connected to two of said linking arms belonging to said respective suspension elements.