(under the class definition) Subject matter relating to boilers having means to prevent the crown sheet over the firebox from being uncovered by water when the boiler is tilted from the normal horizontal position.
SEE OR SEARCH THIS CLASS, SUBCLASS:
490, for allied art.
SEE OR SEARCH CLASS
180, Motor Vehicles,
39, for devices to keep the boiler of a steam traction engine level when going up or down grade.
280, Land Vehicles, 7, for means for levelling a tank or boiler vehicle when on uneven ground.
