PURPOSE: To check weakening of compaction force caused by reaction of impact, and to make moving easy by a method wherein a flat board, with its bottom formed in a V shape section, is fixed at the tip of a tamping part of an impact device, and the upper face of the flat board is connected to a compactor main body with springs.

CONSTITUTION: Main body-side connecting parts 12A, 12A are provided at the main body of a universally used impact device 1 incorporating an impact mechanism and having an impacting part 11. An impacting part-connecting member 35 and flat board-side connecting parts 36A, 36A are fixed by welding or one-piece molding to the upper face of a flat board 30A, for which the bottom 31A is formed in a V shape section with slopes 32, 33 provided, and the tip of the impacting part 11 is fixed by shrinkage fitting or fitting to a connecting hole 34 of the tamping part-connecting member 35. Extension springs 51, 51 of a jump- restraining part 50A are connected at their upper ends with the main body-side connecting parts 12A, 12A and at their lower ends with the flat board-side connecting parts 36A, 36A. The extension springs 51 of the jump-restraining part 50 check weakening of compaction force caused by jumping of the flat board 30 arising from reaction of impact force. With the main body 10 tilted toward the direction of moving, the direction of repulsive force working from the surface of compaction can be tilted too, and component of force is produced in the direction of movement.