A FASTENER INSTALLATION TOOL INCLUDING A HYDRAULICALLY ACTUATED HEAD PISTON

摘要

In a fastener installation tool, a hydraulically actuated head piston (22) is actuated on its power stroke to instal a fastener, and has return means for returning the head piston independently of the hydraulic arrangement. The tool also has a pneumatic hydraulic intensifier (12, 13) for providing the hydraulic actuation above-mentioned. The hydraulic intensifier has a hydraulic cylinder and a piston rod reciprocable in the hydraulic cylinder, and is provided with a seal (54) for sealing between the end of the piston rod and the wall (39) of the cylinder as the piston rod is driven into the cylinder. The seal is separated from the piston rod and is supported on the end face of the piston rod so as to allow radial movement of the end of the piston rod with respect to the seal. The seal may be provided by an assembly which comprises a substantially rigid support member (57) and an annular flexible sealing member (54). The latter contacts both the end face of the piston rod and the annular sealing member. The annular sealing member makes sealing contact with both the support member and the wall of the cylinder.