Magnetic selection ring for an elastic auxiliary selectors and needles

摘要

The present invention relates to a magnetic selection ring (13) having a solid ring-shaped permanent magnet made of ferromagnetic material and defining an external flange (17) being provided with annular recesses (18a, 18b, 18c, 18d). Slots (20) filled with diamagnetic material (21) are provided in the recesses to form heads (22a, 22b, 22c, 22d) each accommodating a core (24) of a respective release electromagnet (15). The invented magnetic selection ring (13) is usable with elastic auxiliary selectors (2) of the type provided with a shaped elastic portion (6), a lower heel (7), which is outwardly flexible for being affected by a lifting cam (9) or inwardly retainable to avoid interference with the cam (9), and an upper heel (8), actuated by a lowering cam (10) formed on the lower surface of a complementary ring (11) for retaining the elastic portions (6) of the elastic auxiliary selectors (2). The elastic auxiliary selectors (2) have a lowermost tapering tab (12), which can be moved by a retraction cam (14) into contact with the magnetic ring (13).