Patent ID: 9169888
Filing Date: 2015-10-27
Classification: F16F,Y10T

Abstract:
1. A method for making a shock absorber, the shock absorber comprising: a cylinder sealingly containing hydraulic fluid; a piston inserted in the cylinder; a piston rod coupled with the piston and extending to an exterior of the cylinder; an outer tube externally disposed around the cylinder; a separator tube externally disposed around the cylinder and including a cylindrical sidewall that defines an annular passage in communication with an interior of the cylinder; a reservoir formed between the cylinder and the outer tube outside the separator tube, the reservoir sealingly containing the hydraulic fluid and gas; and a substantially cylindrical branch tube integrally formed on the cylindrical sidewall of the separator tube, and protruding radially outwardly while defining a passage in communication with the annular passage, wherein the shock absorber is configured to be mounted between relatively movable two members, the method comprising: forming a prepared hole on the cylindrical sidewall of the separator tube; causing a portion of the cylindrical sidewall of the separator tube that surrounds the prepared hole to protrude radially outwardly to form the substantially cylindrical branch tube by burring processing; and pressing a first side and a second side of a proximal portion of the substantially cylindrical branch tube in a circumferential direction or an axial direction of the cylindrical sidewall of the separator tube from an interior to concave an inner circumferential surface radially outwardly to form at least a portion of a first recess spaced apart from the substantially cylindrical branch tube and at least a portion of a second recess spaced apart from the substantially cylindrical branch tube.