Выражение встречается в следующем контексте:
ROLLER PULLING UNIT
FROM 100 mm to 250 mm DIAMETER
IT IS CONSTITUTED BY A UNIT TWO DOUBLE-SET OF PINCHROLLS
THE " V " GROOVE TYPE ROLLS ARE MOTORIZED BY AC CONICAL GEAR MOTOR AND PRESSING UNIT UPSIDE THE BILLETS BY MEANS OF PNEUMATIC CYLINDERS
PLS CONTROL

Заранее спасибо !!!