EP 0086480 B1 19860917 - METHOD FOR THE MANUFACTURE OF FRONT FORK OF SINGLE UNIT TYPE FOR BICYCLES FROM CENTER BUTTED FERROUS TUBULAR MATERIAL
Title (en)
METHOD FOR THE MANUFACTURE OF FRONT FORK OF SINGLE UNIT TYPE FOR BICYCLES FROM CENTER BUTTED FERROUS TUBULAR MATERIAL
Publication
Application
Priority
JP 2120082 A 19820215
Abstract (en)
[origin: EP0086480A2] A front fork blank of the single unit type is manufactured from a center butted tube, the wall thickness of its middle-portion exceeding that of both end portions of the tube, as a starting material. The center butted tube is produced by a known machine including a mandrel and a die. The center butted tube is bent at two positions with the right angle to form a tubular fork. The tubular fork is set in a sectional die which has a concave recess corresponding to a protuberant socket, and subjected to the known oil hydraulic bulge-forming process in order to bulge-form the socket at the middle of the top of the tubular fork. The socket is opened to receive a stem.
IPC 1-7
IPC 8 full level
B21D 53/86 (2006.01)
CPC (source: EP)
B21D 35/006 (2013.01); B21D 53/86 (2013.01)
Designated contracting state (EPC)
DE FR GB IT
DOCDB simple family (publication)
EP 0086480 A2 19830824; EP 0086480 A3 19840321; EP 0086480 B1 19860917; DE 3366171 D1 19861023; JP S58138525 A 19830817
DOCDB simple family (application)
EP 83101399 A 19830214; DE 3366171 T 19830214; JP 2120082 A 19820215