| 摘要 |
Communication apparatus suitable for communicating underwater includes a body assembly (11), a piston chamber (12) in said body assembly, a piston (20) reciprocable within said piston chamber (12), a fluid inlet (14, 16) to said piston chamber (12), porting means (21, 23) including receiving ports (22, 24) spaced axially along said piston (20) for exhausting air received from said inlet (14, 16) to respective opposite ends of said piston (20) and exhaust means (13, 15) from said piston chamber (12). Alternatively, a mechanical arrangement for alternately directing the working gas to respective ends of the body assembly (11) may be provided. Diaphragm means may be adjustably attachable to the body assembly (11) and adjustable from a clearance position at which the diaphragm is clear of the piston (20) at its stroke limit to a contact zone within which the piston (20) impacts against the diaphragm within the stroke limit of the piston (20). The diaphragm is attachable to the body assembly (11) and the piston (20) may impact against it to impart vibration energy to a medium in which the diaphragm is in contact.
|
