High-speed piston propulsion appts. for seismology - has variable volume chamber connected to exterior via expansion chamber with calibrated ports

摘要

The equipment propels at high speed a main piston sliding in a first tubular housing closed at one end, between the base of the housing and a stop at the other end, and returns it to the base again. The variable-volume chamber (5) is connected with the exterior by a first calibrated port (28) in the housing wall and leading to an expansion chamber (33). This has a second calibrated port (35) leading to the exterior. The expansion chamber can extend from the first calibrated port in the opposite direction to the variable-volume chamber, the second port being situated in the latter at a point as far as possible from the first one.