Programmable plate bending machine

A programmable automatically controlled plate bending machine comprising:

• an upper and a lower gripping roll mounted for rotation with a metal plate passing therebetween, said lower gripping roll being supported by slide members and a pressure sensing means for said lower gripping roll;
• lateral rolls placed on either side of said gripping rolls, each of said lateral rolls being mounted for a rotational movement on pivotable arms and a drive means connected to said pivotable arms to move said lateral rolls with respect to said upper gripping roll of the bending machine;
• a position sensing means connected to the pivotable arms to provide position control signals for said lateral rolls and pressure sensing means for said lateral rolls to provide spring-back signals from the metal plate at the start of a bending operation of the bending machine;
• the machine further comprising a curvature sensing device to continuously sense a radius of curvature of the bending metal plate at an exit side of the upper and the lower gripping rolls;
• and a central processing unit, whose input signals includes a position signal and a pressure signal provided by said position and said pressure sensing means, said processing unit comprising a program memory for storing a general operating program of the bending machine, and a memory programmable with a main working program defining predetermined working positions for said lateral rolls, and means to modify said main working program according to data signals received from said position and said pressure sensing means at the start of a working cycle of the bending machine, and to continuously modify said program according to curvature control signals continuously received by said curvature sensing device, during the working cycle of the bending machine.