(under subclass 223) Apparatus wherein the blade (1) comprises plural parts held at spaced intervals, (2) is so shaped as to define or enclose an open area, or (3) comprises a solid member discontinuous in at least one direction.
(1) Note. This definition does not include a mere apertured blade or one comprised or permeable material, such structure being classifiable in subclass 231 below.
SEE OR SEARCH THIS CLASS, SUBCLASS:
69+, particularly subclasses 76+ for operator supported manually actuated impellers, many of which comprise open work type reaction members.
SEE OR SEARCH CLASS
52, Static Structures (e.g., Buildings),
633+, for open work structures of general utility and see the search notes thereunder for similar structure elsewhere classifiable.
