EP 0268894 B1 19920812 - DRAWING DEVICE FOR A PRESS
Title (en)
DRAWING DEVICE FOR A PRESS
Publication
Application
Priority
DE 3640787 A 19861128
Abstract (en)
[origin: US4821552A] A drawing installation for a press which must produce the holding force during the drawing operation. The drawing ram displaces the sheet metal part and the sheet metal holder against the holding force and additionally must overcome at the beginning of the sheet metal deformation the inertia forces of the accelerated parts of the drawing installation. In order to avoid the forces which occur thereby in an impact-like manner, the piston rods transmitting the holding force and the ejector piston rods are pre-accelerated prior to the drawing ram. The piston rods each include an operating surface adapted to be acted upon in the drawing direction. The pressure spaces coordinated thereto are connected with a pressure quantity space each of a pre-acceleration cylinder and by way of a refill control with a pressure source. The control of the pre-acceleration cylinder and of the refill from the pressure source takes place in dependence on the movement of the drawing ram. The drawing installation can be used in presses with mechanically driven drawing rams and sheet metal holders retaining the sheet metal part whereby the functions of holding and ejection are carried out by separate pressure cylinders.
IPC 1-7
IPC 8 full level
B21D 24/08 (2006.01); B21D 24/14 (2006.01)
CPC (source: EP US)
B21D 24/14 (2013.01 - EP US)
Designated contracting state (EPC)
DE ES FR GB IT SE
DOCDB simple family (publication)
EP 0268894 A2 19880601; EP 0268894 A3 19891129; EP 0268894 B1 19920812; CA 1291372 C 19911029; DE 3640787 A1 19880601; DE 3781099 D1 19920917; ES 2033769 T3 19930401; US 4821552 A 19890418
DOCDB simple family (application)
EP 87116280 A 19871105; CA 552810 A 19871126; DE 3640787 A 19861128; DE 3781099 T 19871105; ES 87116280 T 19871105; US 12592487 A 19871130