Patent ID: 8991517
Filing Date: 2015-03-31
Classification: B25D

Abstract:
1. An impact tool which performs a predetermined operation on a workpiece at least by an axial linear movement of a tool bit which is mounted in a front end region of a tool body, the impact tool comprising: a reaction force transmitting member configured to be movable in an axial direction of the tool bit and to be moved rearward, in a direction away from the tool bit, by receiving a striking reaction force caused when the tool bit strikes the workpiece; a first elastic member that biases the reaction force transmitting member forward; and a second elastic member configured to be pushed by the reaction force transmitting member and compressively deform, thereby cushioning the striking reaction force, when the reaction force transmitting member moves rearward by receiving the striking reaction force, wherein a first initial load of the first elastic member is set to be smaller than a second initial load of the second elastic member, when the tool bit is pressed against the workpiece, the reaction force transmitting member is pushed by the tool bit and compresses the first elastic member as the second elastic member remains uncompressed relative to the second initial load, so that the reaction force transmitting member is placed in a predetermined working position in the longitudinal direction, and when the reaction force transmitting member receives the striking reaction force in the working position, the reaction force transmitting member moves rearward in the axial direction of the tool bit and compressively deforms the second elastic member, thereby cushioning the striking reaction force, and the first and second elastic members are arranged in tandem in the axial direction of the tool bit.