US Patent 7150384 Power-driven nailing machine

A contact member of a power-driven nailing machine is provided with a ring portion, a guide arm, and a guide portion. The ring portion is projected outwardly beyond a lower end of a nose portion and can keep a clearance from the lower end. The guide arm is extended upwardly from one end of the ring portion along a side surface of the nose portion. The guide portion is provided on an upper portion of the guide arm and can be slidably guided to the nose portion. The nose portion includes a projecting piece projected from the outer peripheral surface of the lower end toward an inner peripheral surface of the one end of the ring portion.