Subsurface-Explorer Robot With Spinning-Hammer Drive

A proposed robotic apparatus for underground exploration would propel itself downward in a percussive manner reminiscent of a jackhammer, pile driver, or hammer-and-chisel combination. Called a "subsurface explorer" (SSX), the apparatus (see figure) would include a hammer that would be moved within a generally cylindrical housing to repeatedly strike a chisel in the form of a rounded nosepiece at its front (lower) end. Each impact of the hammer on the chisel would give rise to an impact of the chisel on the rock and/or soil at the front. The rock (if any) at the front end would be crushed into fine particles. Upon each impact, the apparatus would advance a small distance downward; concomitantly, the soil and/or rock particles would flow upward relative to the housing and would become recompacted behind (above) the apparatus. Thus, the apparatus would bury itself and, unlike in drilling, there would be no need to remove ground material to form a hole.