Hans-Joachim Pahnke Book

18 19
In all the frame concepts discussed above, Hans-Joachim Pahnke had the conviction
that the working piston should not be rigidly integrated with the
frame guiding, as was common with the competitors. Therefore the press
frame was made with sufficient guiding length and a pendulum type connection
was used between the main piston and the movable frame. All SACK and
subsequent PAHNKE presses thus reached a considerably higher lifespan for
the cylinder packing and the piston guide bushings. Typically, the service life
of the seals was up to ten years with this design and corresponding figures
from competitors were much lower.
SMS (Schloemann, Düsseldorf) and DEMAG- Hydraulik (Duisburg) subsequently
developed two-column frame designs; with questionable success,
because the working piston mostly remained integrated in the frame guiding
system and round columns continued to be used.
It was not long, before this new press design was copied by other firms, including
foreign press manufactures. The English company DAVY was the first
to successfully implement the SACK two-column design.
Working cylinder with power transfer
via a dual-supported pendulum
14 MN underfloor press
from Schloemann
Schloemann forging plant with integrated control
18 MN underfloor press from DAVY
At the time, it was not easy for SACK GmbH to position itself against the
mostly cheaper frame designs from the competition. However, under Hans-
Joachim Pahnke, it was nevertheless possible to achieve sales success due to
his talent for presenting his design in a convincing manner and successfully
completing contracts exceeding customer expectations.