초록 ▼

A process for making a light-weight, heavy duty steel piston for a disc brake. The initial blank is formed to include the piston nose radii and angle. The blank is then simultaneously rolled by three rollers, one of which rollers forms the piston boot groove, another of which rollers maintains the o

A process for making a light-weight, heavy duty steel piston for a disc brake. The initial blank is formed to include the piston nose radii and angle. The blank is then simultaneously rolled by three rollers, one of which rollers forms the piston boot groove, another of which rollers maintains the outer diameter of the main portion of the piston, and the other roller of which forms near the outer end of the piston an overall diameter which is less than the main overall diameter. During the rolling step, the metal deforms to form a contour opposite the base of the piston boot groove such that the thickness of the wall between the contour and the base of the piston boot groove is smaller than the thickness of the main portion of the wall, but yet is strong enough to withstand heavy duty disc brake operation throughout the life of the disc brakes.

대표청구항 ▼

A process of manufacturing an article, comprising the steps of: making a cup-shaped article blank which includes at least one substantially curvilinear wall member having a first substantially curvilinear surface and a second substantially curvilinear surface disposed substantially opposite to said

A process of manufacturing an article, comprising the steps of: making a cup-shaped article blank which includes at least one substantially curvilinear wall member having a first substantially curvilinear surface and a second substantially curvilinear surface disposed substantially opposite to said first substantially curvilinear surface, such that said article blank is substantially in the shape of a piston for a disc brake; rolling a piston boot groove in a first predetermined area of said first substantially curvilinear surface of said substantially curvilinear wall member while permitting a second predetermined area of said second substantially curvilinear surface to deform to predetermined dimensions during said rolling step, said second predetermined area of said second substantially curvilinear surface being disposed substantially opposite to said first predetermined area of said first substantially curvilinear surface; controlling the dimensions of said article blank during the aforesaid rolling step so that the thickness of said substantially curvilinear wall member between the base of said piston boot groove and said second substantially curvilinear surface is less than the thickness of said substantially curvilinear wall member between said first and second substantially curvilinear surfaces at areas remote from said piston boot groove; making said article blank wherein said first and second substantially curvilinear surfaces are disposed concentric to a central axis, and wherein said article blank is provided with a transverse portion which is disposed substantially transverse to said central axis and said first and second substantially curvilinear surfaces, said transverse portion having its thinnest dimension adjacent to said central axis and having its thickest dimension contiguous with said substantially curvilinear wall member; and after said rolling step, facing off the end surface closest to said groove so that said faced off surface is substantially perpendicular to said central axis.