4-roll bending machines have been developed for walled offshore wind tower sections, piles, mooring posts, large vessels, and tanks.
The Graebener 4-roll bending machine with supporting yoke is equipped with relatively slim rolls with hardly any crowning. The number of exchange rolls necessary is decreased considerably and an optimum straightness of the pipe shells to be formed is ensured - for small and large material thicknesses. Due to the small number of exchange rolls, standstill times because of roll changes can be avoided which, in turn, increases the turnout of the machine and its efficiency.
The supporting yoke clamps the top and bottom rolls and compensates the deflection by applying counter pressure to the rolls. Camber adjustments at the rolls are no longer necessary, bending capacity turns into pre-bending capacity, and the customer no longer needs to commit himself to a predefined production program.
Due to the supporting yoke function it is finally possible to raise the pre-bending capacity of a roll to the same level as the round bending capacity. Flame cutting of the straight edges, which has been customary so far, no longer is necessary thus saving working time and material costs while at the same time increasing the economic efficiency.
If the supporting yoke is not needed, it can be fully sunk in the foundation or even dismantled in a very short period of time.