Patent ID: 8732963

Claim:
An electric hand power-tool comprising: a lifting rod configured to support a working tool; a voltage source; a piston fixedly connected to the lifting rod; a spring wrapped around a portion of the lifting rod and braced at one end on the piston; a tubular elastomer module positioned at least partially surrounding the lifting rod and braced on the piston rod concentrically with the spring, wherein the tubular elastomer module is configured to perform at least one of an expansion and a contraction in response to electrical voltage is being applied to the tubular elastomer module by the voltage source, and wherein the at least one of the expansion and the contraction of the tubular elastomer module moves the lifting rod and the working tool in a first direction from an initial position, and the spring is configured to restore the lifting rod and the working tool to the initial position after the at least one of the expansion and the contraction to produce an oscillating translational motion of the working tool.