Patent ID: 7127792
Filing Date: 2006-10-31
Classification: B21D,B23P,F16F,Y10T

Abstract:
1. A method of manufacturing a spring assembly, which includes an annular plate and a compression coil spring, and which is adapted to assemble the compression coil spring to the annular plate by caulking a projection portion formed in the annular plate, the method comprising: forming the projection portion in the annular plate, the projection portion being opposite to the compression coil spring; alternately providing plural large-diameter walls and plural small-diameter walls in a circumferential direction of the projection portion; and inserting a punch having a portion, whose diameter is larger than an inside diameter of a space between the small-diameter walls, inside a space surrounded by the large-diameter walls and the small-diameter walls of the projection portion, the punch forcibly and outwardly spreading the small-diameter walls, thereby enlarging the large-diameter walls adjoining each of the small-diameter walls and the projection portion in diameter.