(under subclass 516) Apparatus in which the working medium is a liquid during at least a portion of a complete cycle of the operation of the motor.
SEE OR SEARCH THIS CLASS, SUBCLASS:
527, for apparatus employing a mass which is in a solid state during a portion of its cyclic operation and which may or may not change to a liquid state during another part of its
cyclic operation (e.g., wax).
SEE OR SEARCH CLASS
337, Electricity: Electrothermally or Thermally Actuated Switches,
306+, for switches actuated by thermally expanded or vaporized fluid. 374, Thermal Measuring and Testing,
201+, for temperature measurement in which an expanding or contracting fluid drives an indicator.
