Controlled length cuts of rubber being continuously extruded - using shear motor linked potentiometer fixed to arm inside loop of rubber formed while one end is held stationary for cutting

摘要

Rubber section being continuously extruded (1) is cut into controlled lengths using two electric motor driven transport units (2,3), a rotating shear (4), and control of motor speed in relation to the size of the loop formed by the continuous extrusion while the strip is held stationary for cutting. The size of the loop(6) is measured by an arm (8) pivoted at one end and having a potentiometer(9) fixed to the pivoted end and a roller (7) which runs inside the loop at the other end. As the loop grows the arm falls, and the potentiometer passes an increasing voltage to a voltage to frequency converter which controls the speed of the stepper motor driving the traction unit (3) on the shear side of the loop. The output pulses from the voltage to frequency counter are counted and compared to a manually set count to stop the shear end traction unit (3) while the shear (4) operates, and to operate the shear.