double-acting hammer [机] 复动式锻锤

double-duty double-acting hammer 两用双动锤

double acting pile hammer 复动桩锤 ; 双动式打桩锤

double-acting stream hammer 双动气锤

double acting pneumatic hammer 双作用气动桩锤

Hammer double acting pile 双动桩锤

double-acting type pneumatic pile hammer [建] 双作用式气动桩锤

double-acting pile hammer 复动桩锤