| 摘要 |
Disclosed herein is a power feed system for translating a rotary drill head along the length of a guide tower. The system utilizes a compound balanced area, end fed hydraulic cylinder as the actuating means. This arrangement provides a large ratio of fixed overall length to usable travel distance, balanced feed force in both directions, direct connection of the rotary head to the outer stage of the cylinder, and drift-free operation, all without the need for moving hydraulic hoses. |
