Abstract: A resilient returning device for a power operated piston tool comprises a one piece elastic bellow-shaped body including a plurality of repeating pleats, each of which has two pleat halves that cooperatively define a first elbow therebetween. Each of the pleat halves of each of the pleats cooperates with an adjacent one of the pleat halves of an adjacent one of the pleats to define a second elbow therebetween. Each of the first and second elbows has a bulging side. The bellow-shaped body is formed with a plurality of loop-shaped grooves that are indented from the bulging sides of the first elbows of the pleats or the bulging sides of the second elbows of the pleats, respectively.

Abstract: A position-limiting device forms a portion of a magazine assembly of a powder-actuated fastener-driving gun, and includes a nail-guiding pipe and a clamping unit. The nail-guiding pipe extends through a sleeve of a magazine assembly such that an end of the nail-guiding pipe is disposed outwardly of the sleeve. The nail-guiding pipe includes a tubular body, a nail passage hole formed in the tubular body and in spatial communication with the nail-receiving space in the magazine housing so as to allow one of the nails to be moved from the magazine housing into the nail-guiding pipe therethrough, and two aligned apertures formed respectively in two opposite sides of the tubular body. The clamping unit is disposed on the nail-guiding pipe, and extends through the apertures for clamping the one of the nails disposed within the nail-guiding pipe.