Patent ID: 7784394
Filing Date: 2010-08-31
Classification: B21D,F16B,Y10T

Abstract:
1. A joined rod comprising: a bolt member having a female part at one end thereof; and a piston rod having a plurality of annular grooves on an outer surface of a first end part thereof, the first end part of the piston rod being received within the female part, wherein the piston rod has a second end opposite to the first end part; wherein the annular grooves on the piston rod are trapezoidal in cross-section, each of the annular grooves having a first wall surface and a second wall surface, the first wall surface being closer to a joint end of the piston rod than the second wall surface, the first wall surface being perpendicular to an axis of the piston rod and the second wall surface being inclined with respect to the axis of the piston rod, wherein the piston rod has an oil seal for sealing an outer cylinder of a hydraulic shock absorber, the oil seal being disposed on the outer surface of the piston rod between the second end of the piston rod and the annular grooves by sliding over the annular grooves from the joint end, wherein the bolt member and the piston rod are joined together coaxially through annular clinches formed by radially and locally pushing a side wall of the female part of the bolt member into the annular grooves on the piston rod by a mechanical clinching technique when the first end part of the piston rod is received within the female part of the bolt, and wherein the bolt member is a mounting member having a mounting part at a second end thereof for securing the joined rod to another structure.