| 摘要 |
PURPOSE:To accelerate a pile-driving speed, by a method wherein a rotary shaft, which a coil shaft engages, is connected to a lower end of an auger shaft, the rotation of the shaft lifts a hammer mating the outside thereof, and the hammer falls under its own weight at an upper limit. CONSTITUTION:A pile E is attached to a lower end of an earth auger through a rotary shaft 3. If, with a motor for an earth auger run in a condition of an operator while gripping a handle a coil rail engaging the shaft 3 rotates, too. In this case, the hammer 1 is free of rotation as a result of the engagement of a guide 26 with a guide groove 27, whereby a steel ball 29, emerging from an axial hole 26 surface through the force of a push pin 31, engages the rail 8, and is pushed upward by a push pin 31. If the hammer 1 reaches an upper limit, a pushing projection 60 makes contact with an upper end of a lock-releasing pin 53 to push it down, an oil pressure in a hydraulic chamber 56 pushes upward a piston 43, a lock pin 41 is unlocked, the steel ball 29 moves backward, and the hammer 1 falls to strike a blow on the pile E. |
