(under the class definition) Apparatus comprising a device which is inserted into an opening in hard material and is described as operated to apply such expansive pressure to the walls of the opening as to relatively move and break up the hard material.
(1) Note. A means which is sealed into an opening and is described as supplying fluid pressure into the opening to break down material by expansive pressure, even though the fluid directly engages the material, is included under this definition.
SEE OR SEARCH THIS CLASS, SUBCLASS:
16+, for a process of breaking down material by direct fluid pressure.
SEE OR SEARCH CLASS
102, Ammunition and Explosives
301+, for a process or apparatus for rendering a heavy mass by the sudden release of gases under heavy pressure, such as an explosion. 166, Wells,
177.5, for a means for fracturing a formation traversed by a well, and subclasses 179+ and the subclasses there noted for expansible packers or plugs, and subclasses 206+ and the subclasses there noted for expansible anchors.
