3 Fundamentals of press design

518 Solid forming (Forging)
Feed systems
A number of different feed systems can be used to transfer the parts
through the press and into the dies. The so-called transfer feed system
is the dominating method for vertical multiple-step presses. Feed systems
come in a dual-axis version, or with an additional lifting stroke for
long parts, in the form of a tri-axis transfer. The control cams are driven
in mechanical presses by direct coupling with the press drive system. In
the case of hydraulic presses, the various units are actuated by servo drive
systems (Fig. 6.8.11).
Hydraulically driven swivel-mounted grippers are used to transport
heavy pressed parts with weights over 5 kg (Fig. 6.8.12). The controlled
grippers are configured for a substantially higher clamping force than is
possible using transfer feed systems. The swivel-mounted grippers generally
execute a lifting movement. A loading arm (swivel or linear movement)
is used to transfer the parts from the loading station into the first
pressing station, and one gripper arm is allocated to each die station.
Fig. 6.8.11
Two-axis transfer feed
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998