STRAPPING MACHINE WITH STRAP FEEDOMG AMD TIGHTENING UNIT

摘要

A strapping machine comprises a strap extension, retrieval and pulling unit (13) comprising in turn a Powered main wheel (18) around which the strap (12) winds partially to be moved in both directions. The unit comprises two selectable mechanisms for transmission of movement to the main wheel. The first mechanism causes rotation of the main wheel (18) at a first speed and an auxiliary traction wheel (21) which is pressed against the main wheel with interposition of the strap near the strap input zone on the main wheel to effect pulling of the strap. The second mechanism causes rotation in both directions of the main wheel (18) at a second speed greater than the first to effect extension and retrieval of the strap while the auxiliary traction wheel (21) is at some distance from the main wheel. A control device (50) operates alternatively the first or second mechanism to realize in rapid succession extension, retrieval and pulling of the strap.