(under subclass 196) Subject matter wherein the structure for admitting light is located on a top covering portion (i.e.,
roof) of the ventilated space.
(1) Note. See the Search Notes below for references to lines between Class 454 and other classes.
(2) Note. Exterior vault or manhole covers are not included in this subclass.
SEE OR SEARCH THIS CLASS, SUBCLASS:
48, for an exterior vault or manhole cover which may also admit light.
SEE OR SEARCH CLASS
49, Movable or Removable Closures, appropriate subclasses for a mere through passage in a barrier combined with a closure for the passage of air. And see Lines With Other Classes of the Class 49 class definition for the line between Class 49 and Class 454. 52, Static Structures (e.g., Buildings),
18, 80, 198+, and 200 for skylight-type fixtures. And see the Class 454 search notes in the Class definition of Class 52 for the line between the two classes.
