(under subclass 132) Method or apparatus wherein the passageway is generally perpendicular to the earth's surface.
SEE OR SEARCH THIS CLASS, SUBCLASS:
8+, for pressurized caissons.
231+, for a hollow pier or caisson, which may be subsequently filled, employed as a foundation structure.
272, for a temporary caisson or other shoring means employed in a shaftlike excavation.
SEE OR SEARCH CLASS
166, Wells, 242.1+, for well casing not sunk by a caisson or the like; and subclasses 378+ and 381+ for methods of constructing or assembling a well involving more than merely sinking a shaft by a caisson or the like or using means for sinking a shaft other than a caisson or the like.
