EP 0317905 B1 19920805 - METHOD OF DRAWING WELDLESS TUBES
Title (en)
METHOD OF DRAWING WELDLESS TUBES
Publication
Application
Priority
- DE 3739730 A 19871124
- DE 3805838 A 19880225
Abstract (en)
[origin: JPH01202310A] PURPOSE: To automatically transport the next tubing to a die and to improve the efficiency of drawing by mutually fixing plural tubing, shifting a mandrel outside the action zone of the die during a joint is passed through the die and, after the joint is passed through the die, making the mandrel reach within range of the die. CONSTITUTION: The plural tubing are mutually connected before a drawing stage or in the midst of the stage. Then, the tubing 7a having the same dimension of cross section are supported above a bundle 7 of rings, the beginning and end of the bundle 7, 7a of the rings are connected. At the time of drawing, when the connected place 9 reaches within the range of the die 3, the mandrel 8 is shifted in the opposite direction to the drawing direction and does not act on the tube wall together with the die 3. Only the hollow drawing of the tubing 1 is executed and the reduction of wall thickness is not generated. The shift of the mandrel 8 is executed by providing ejecting parts 10, 11 at the front and rear ends of the tubing 1 and the mandrel 8 is automatically released. Next, after the connected place 9 is passed through the die, the mandrel 8 reaches within the action zone of the die 3 and the tubing is drawn.
IPC 1-7
IPC 8 full level
B21C 1/00 (2006.01); B21C 1/22 (2006.01); B21C 1/24 (2006.01); B21C 1/30 (2006.01); B21C 1/32 (2006.01); B21C 3/16 (2006.01)
CPC (source: EP US)
B21C 1/24 (2013.01 - EP US)
Designated contracting state (EPC)
AT BE ES FR GB IT NL SE
DOCDB simple family (publication)
EP 0317905 A2 19890531; EP 0317905 A3 19891025; EP 0317905 B1 19920805; DE 3805838 A1 19890907; DE 3805838 C2 19970313; ES 2034123 T3 19930401; FI 885335 A0 19881117; FI 885335 A 19890525; FI 95542 B 19951115; FI 95542 C 19960226; JP 2672355 B2 19971105; JP H01202310 A 19890815; US 4856703 A 19890815
DOCDB simple family (application)
EP 88119170 A 19881118; DE 3805838 A 19880225; ES 88119170 T 19881118; FI 885335 A 19881117; JP 29482388 A 19881124; US 27558588 A 19881123