The owner-managed family business Wiedenmann-Seile has successively expanded its original business area of slings. Today, the portfolio is characterized by other areas relating to fall protection, crane and lifting technology as well as special steel construction. One focus of the company's own steel fabrication is customized hydraulic presses with a pressing force of up to 1,000 t (10,600 kN). The steel manufacturer relies on Jebens to produce the large, heavy flame-cut parts required for this from high-strength S690 grade steel.

Today, the Wiedenmann Group has around 150 employees at six locations. Sophisticated, customer-specific custom-made products and comprehensive services characterize the medium-sized company. In 2010, the company founded its own steel fabrication shop with 20 employees in response to the continuously increasing demand for individual steel construction. Its focus is on the development, design, calculation, welding processing and final assembly of special constructions.

Thanks to the close cooperation with Enerpac, world market leader in the field of tool hydraulics, hydraulic presses are increasingly taking up space in the Stahlmanufaktur's order book. Large manufacturers of construction and agricultural machinery are among Wiedenmann's press customers, as are transmission manufacturers and renowned research institutes, as Volker Kohlhepp, Commercial Director of Stahlmanufaktur and member of the management board, explains. In his experience, decades of know-how in development, design and production are crucial for the customized design of each press. "Component feeding, ease of operation and easily accessible maintenance units on our presses contribute significantly to production efficiency and customer satisfaction," says Kohlhepp. According to him, Wiedenmann enjoys a unique position with the roller frame presses developed in-house, in which the press frame, which is mounted on rollers, moves along a rigid table like a portal over the pressed material.

Press table with a special highlight

With the press bed, 11 different press bed inserts and the basic components of the mobile upper yoke, Jebens manufactured core elements of the basic design for this high-end press. © Wiedenmann ropes

An example of this is a 4 m high and 2.8 m wide roller frame press with a press force of 3,193 kN, a table length of 3.8 m and a dead weight of 13 tons. It is used for pressing and straightening components at a leading international manufacturer of gear drives for wind energy, industry and transportation. The roller frame construction of this workshop press, which is solidly welded and fully electrified in the steel fabrication shop, can be moved by 1,750 mm. This also allows the press to be loaded by crane for heavy components. Its electromechanically adjustable upper yoke can be set to the desired height in five stages. The hydraulic cylinder mounted in the center of the upper yoke locks automatically in the new position. Hydraulically moved pins form the force-transmitting connection between the top yoke and the columns. The hydraulic unit and control unit are mounted on the press frame and move with it.

As the press stiffens in conjunction with the table, which moves automatically forwards, it forms a closed pressure system so that no force is transferred to the floor. As a special highlight, Wiedenmann has also integrated insert openings for press inserts of different sizes into the tabletop instead of the usual stiffening ribs. They can be exchanged depending on the type of component to be machined, thus opening up a significantly wider machining spectrum for the operator.

It took just six weeks from the first contact to the basic specification of the press, calculation, processing of an extensive specification sheet, placing of the order, presentation of the basic design including a detailed description. Wiedenmann only needed four months from placing the order to delivery - including calculation, detailed design, production, assembly, test phase and painting.

120 millimeter thick fine-grained steel

With the press bed, eleven different press bed inserts and the basic components of the mobile upper yoke, Jebens manufactured core elements of the basic construction for this high-end press. As the assembly of all other components was based on this, the delivery deadline of just two weeks was, as always, very tight. The availability of the high-strength steels in Jebens' own warehouse - in reliable quality thanks to its affiliation with Europe's leading heavy plate manufacturer Dillinger - was therefore once again a point in Jebens' favor. The high pressure load required S690 QL fine-grained steel for the press bed and inserts.