Patent 7861798 was granted and assigned to Von Arx on January, 2011 by the United States Patent and Trademark Office.
A hammer device in the form of a needle gun. The gun includes a cylinder housing containing a cylinder, in which a flying piston is displaced and an anvil, against which the piston strikes. A needle carrier is located on the anvil, and the needles of the gun are held in the carrier so that the needles can be longitudinally displaced. To reduce the wear on the needle carrier and to preserve the needle heads of the needles, the needle carrier is configured from several layers, at least in the vicinity of the guide plate. The layers are of alternating hard and soft material.