Abstract: A laser thickness gauge has three laser displacement sensors each transmitting a laser beam onto a target web. Two sensors are spaced along the web and face one surface of the web and the third sensor faces the opposite surface. The thickness of a web that is positioned along a passline plane between the sensor is measured even when the passline plane is not perpendicular to the beams of the sensors. A data processor computes the passline angle from the distance measurements communicated from the three sensors. During setup and calibration, data representing physical characteristics of the gauge are measured and stored and during operation are processed with currently measured data to generate correction factors that are used to correct thickness measurements determined from the three laser sensors.

Abstract: An extrusion line for producing rubber tire tread. Method and apparatus for continuously controlling extrusion line operation to maintain a predetermined length and weight for the finished product. Sensors for unit weight, extruder speed and swell, extruder load, extrudate temperature at the extruder and at the skiver, and conveyor speeds, signal conditioning circuits, and controls for take away conveyor speed, extruder speed, unit weight and skiver length.