| 摘要 |
PURPOSE:To obtain a great impaction force by using a drop hammer in which a coil spring is provided to a cap at the upper end of a casing, and the spring is deformed by compression when pulling up a weight and deformed to return to an original shape when dropping. CONSTITUTION:A pinion gear 34 is turned by operating a liquid-pressure device 40, and a weight 24 in supported state is pulled up in a casing 16 until a proper flexion is produced in a coil spring 20. Afterwards, when the coupling between the pinion gear 34 and a rack gear 44 is released by operation of the liquid- pressure device 40, the weight 24 is detached from the rack gear and dropped by receiving the repulsion of the coil 20, or downward force. |
