(under the class definition) Apparatus including (1) an indicator, register, recorder or alarm responsive to a condition of operation or position of a part of the expansible chamber device or of the working fluid or (2) a window in a wall of an expansible chamber device part to permit inspection of normally hidden portions of said part or of the working fluid.
(1) Note. An expansible chamber device part made of a material which may be transparent (e.g., a glass piston or cylinder) is excluded, unless the disclosure specifies that such material was used for the purpose of allowing inspection of interior portions of said part.
(2) Note. A visible element associated with an expansible chamber device (e.g., fastening or securing means for an expansible chamber device parts) which is specifically intended to become distorted when some malfunction of some part of the expansible chamber device occurs to indicate such malfunction is included under this definition.
SEE OR SEARCH CLASS
91, Motors: Expansible Chamber Type,
1, for a signal, indicator or inspection window to indicate a condition of operation of an expansible chamber type motor. 340, Communications: Electrical,
500+, for electrical automatic condition responsive indicating systems.
