Abstract: An embodiment discloses a brake booster input rod, including: a front end portion to which an input piston of a brake booster is connected; a rear end portion to which a yoke connected with to a brake pedal is attached; and an annular boot installing groove to be engaged with, when a boot covers a front portion of the input rod, a rear end bead portion of the boot with a fastening margin. Through rolling, two annular groove portions and an annular ridge portion are formed to each have a triangular section. The ridge portion functions as a rear side wall of the boot installing groove.

Abstract: An embodiment discloses a brake booster input rod, including: a front end portion to which an input piston of a brake booster is connected; a rear end portion to which a yoke connected with to a brake pedal is attached; and an annular boot installing groove to be engaged with, when a boot covers a front portion of the input rod, a rear end bead portion of the boot with a fastening margin. Through rolling, two annular groove portions and an annular ridge portion are formed to each have a triangular section. The ridge portion functions as a rear side wall of the boot installing groove.

Abstract: A vacuum pressure booster has a booster shell; a booster piston; a valve cylinder including: a valve piston; an input rod; a control valve; and an input return spring, and the control valve including: an annular vacuum pressure introducing valve seat; an atmosphere introducing valve seat; a valve body including: an annular attaching bead portion; an expansion cylinder portion; and an annular valve portion; and a valve spring, wherein the attaching bead portion is tightly held by a pair of cylindrical holding portions formed in a pair of valve holders attached to the valve cylinder, and the diameter of the holding portion is smaller than the inner diameter of the valve cylinder.

Abstract: A vacuum pressure booster has a booster shell; a booster piston; a valve cylinder including: a valve piston; an input rod; a control valve; and an input return spring, and the control valve including: an annular vacuum pressure introducing valve seat; an atmosphere introducing valve seat; a valve body including: an annular attaching bead portion; an expansion cylinder portion; and an annular valve portion; and a valve spring, wherein the attaching bead portion is tightly held by a pair of cylindrical holding portions formed in a pair of valve holders attached to the valve cylinder, and the diameter of the holding portion is smaller than the inner diameter of the valve cylinder.