| 摘要 |
A detachable head for ramming a pipe casing including an external ring having a first diameter, wherein the first diameter is operatively sized to enable the external ring to engage with an outer surface of the pipe casing, a reaction ring having a second diameter, wherein the second diameter is smaller than the first diameter, and operatively sized to enable the reaction ring to engage with a front surface of the pipe casing, an internal ring having a third diameter, wherein the third diameter is smaller than both the first and second diameters, and operatively sized to enable the external ring to engage with an inner surface of the pipe casing, and wherein the reaction ring is secured between the internal and external rings. |
