Patent 7975777 was granted and assigned to Bosch on July, 2011 by the United States Patent and Trademark Office.
A device for impacting a fastener in one embodiment includes a drive channel, a cylinder opening at an end portion to the drive channel, a microcellular polyurethane elastomer (MPE) bumper fixedly positioned at the end portion of the cylinder, the MPE bumper including a drive bore extending therethrough and aligned with the drive channel, and an outer wall defining a plurality of grooves extending radially about the MPE bumper, and a drive mechanism including a drive blade aligned with the drive bore.