(under subclass 8) Structures in which a fluid designed to carry an electric current is utilized; or in which a vacuum is employed for any purpose.
(1) Note. This subclass includes devices within the class definition having as a part thereof an electric conductor formed by a fluid (e.g., mercury).
SEE OR SEARCH CLASS
200, Electricity: Circuit Makers and Breakers,
32, 81.6 and 152 for electric circuit makers and breakers in which contact is made through a conducting fluid, usually mercury.
220, Receptacles, 2.1+, for envelopes and housings which are designed to be evacuated for electric lamps, electric space discharge devices and similar devices where no electrical structure is claimed.
313, Electric Lamp and Discharge Devices, appropriate subclasses for electric space discharge devices which have an evacuated or gas or vapor filled envelope and in which a part of the current path is the evacuated or gas or vapor filled space, and
233, and 315+ for electric lamps which are provided with an evacuated envelope.
335, Electricity: Magnetically Operated Switches, Magnets, and Electromagnets,
47+, for electromagnetically activated switches in which contact is made through a conductive fluid.
337, Electricity: Electrothermally or Thermally Actuated Switches,
21, for electrothermal or thermal switches employing conductive fluid, subclasses 25+ for such switches combined with electric discharge means and subclasses 28+ for similar switches combined with space discharge devices.
