An improved vibrating power hammer for driving and extracting piles

Claim 1

A vibrating power hammer device for forming piles in casing pipes and the like and driving them into and extracting them from the ground comprising a vibrator having spaced upper and lower stops, means to fixedly mount said stops on said pile, a beater movably mounted between said stops, two subassemblies of counterrotating eccentrics mounted on said beater to impart thereto vibrating motion against one of said stops thus causing said driving and extraction of the pile, means for controlling the direction of impacts of the beater, each said eccentric subassembly comprising a drive motor having a drive shaft, two eccentrics pivotally mounted on said beater, driving gear means mounted on both ends of said drive shaft and coupled to said eccentrics, and damping means for suspending said motor on the beater in such manner as to be able to move along a radius equal to said driving gears thus maintaining a fixed interaxis distance in the course of relative motion of the beater with respect to the drive motor.