Apparatus for Working Tubes, Bars, Sections and Similar Blanks, Comprising a Plurality of Machines Arranged in Line

An apparatus for working elongated blanks (C), such as tubes, bars, sections and strips, comprising a plurality of machines (10, 12, 14) arranged in line along a longitudinal direction (x) coinciding with a feed direction of the blank (C),

• each of said machines (10, 12, 14) comprising at least one working member (18, 20, 22), which is rotatably mounted about an axis of rotation (z1, z2, z3) and is adapted to work on the blank (C) so as to apply on it a force having a component directed along the longitudinal direction (x), a driving unit for driving said at least one working member (18, 20, 22) into rotation, and a control unit for controlling said driving unit,
• wherein each machine (10, 12, 14) is provided with a measuring device (24) for providing the control unit of said machine with a measure of an overall reaction force exerted in operation by the blank (C) on said machine along the longitudinal direction (x), and
• wherein the control unit of each machine (10, 12, 14) is arranged to control said driving unit in such a manner that the value, provided by said measuring means, of the overall reaction force exerted in operation by the blank (C) on said machine along the longitudinal direction (x) is equal to a predetermined value, zero included.