(under the class definition) Apparatus which by relative rearrangement of its parts or by the addition or omission of a part is so changed as to operate in a different way or change its function or enhance its operation in some way.
SEE OR SEARCH THIS CLASS, SUBCLASS:
82, for the combination of a rotary nonexpansible chamber-type pump and a jet pump in which the location of the jet pump is changeable by assembly or disassembly.
236, for pumps convertible to basic subject matter of another class.