FOUR-ROLL SHEET BENDING MACHINE Russian patent published in 2002 - IPC

FIELD: sheet bending. SUBSTANCE: machine includes upper and lower pressure rolls supporting hydraulic motors, two lateral rolls, hydraulic cylinders carrying supports for lower and lateral rolls. Hydraulic drive for moving upper and lower rolls is in the form of two mutually separated pressure sources. One pressure source is communicated with hydraulic motors of upper roll, other pressure source is communicated with hydraulic motors of lower roll. Hydraulic drive also includes one more pressure source connected with hydraulic motors of both rolls through non-return valves. Hydraulic drive of lower roll provides positioning of roll on any portion of its motion path at milling shell. EFFECT: improved quality of shells. 2 cl, 7 dwg