| 摘要 |
<p>High-speed flying shears with contrarotating blades (13) fitted to blade-holder drums (30), which is suitable to shear bars (11) travelling at 120 metres per second or more, the shears comprising upstream a first one-channel switch (16) of a start/stop type conveying the bars (11) lengthwise and capable of being oriented laterally by rotation on a plane substantially containing the axis of travel of the bars (11) and parallel to, and between, the planes containing the axes (12) of rotation of the pair of blade-holder drums (30) so as to make the bars (11) pass in the shearing area (35), the circumferential position of the blades (13) being associated with the lateral position of the first one-channel switch (16) at least in the transient moment of the passing of the bars (11) in the shearing area (35), guide means being included downstream to guide the bars (11) deprived of their leading and trailing ends, these guide means cooperating downstream with a coil-forming headstock (27) or with a winding unit, the downstream guide means consisting of a second one-channel switch (20) capable of being oriented laterally by rotation substantially on the same plane of orientation as the first one-channel switch (16) and in synchronisation therewith (16), the first and second switches (16-20) having at least a first extreme position (A-A'), a second extreme position (D-D') and a position for the passage of a bar (E), the position (E) for the feed of the bar (11) being in the vicinity of the first shearing blades (13) and located on the same side as the second extreme position (D-D'), the blade-holder drums (30) comprising first shearing blades (13) and coordinated second scrap-shearing blades (18), the first shearing blades (13) and second scrap-shearing blades (18) being positioned side by side on radial planes on the blade-holder drums (30). Method to shear the leading and trailing ends of a rolled bar (11) travelling at even more than 120 metres per second, the method employing a flying shears as described above. <IMAGE></p> |
