(under subclass 267) Apparatus in which a part is provided which is specifically described as being dropped from above ground to an operative position below ground, said part functioning to cause operation of the fluid shifting means, for example, by (1) operating a latch, (2) providing a fluid reacting surface or (3) operating a valve or other means to permit movement of the cutter element.
(1) Note. Patents are classified in this subclass which specifically describe the part as being a dropped element even though no such recitation is made in the claims provided the part itself is claimed.
SEE OR SEARCH THIS CLASS, SUBCLASS:
270, and the subclasses there noted, for other devices employing a dropped element.
