shedding device of electrical engineering metiersa weaves

摘要

1369149 Shedding motions SULZER BROS Ltd 16 Oct 1972 [16 Oct 1971 13 Nov 1971 (2)] 47592/72 Heading D1E A shedding motion comprises a rotating drum 5, over which a number of harness lines 3 pass, and means for varying the electrical attraction forces between the drum surface, and each harness line, to vary the friction between the lines and the drum so that selected ones are moved by the rotating drum to shed the corresponding heald 1, 2. The means for varying the electrical' attraction may employ the Johnson-Rahbek effect, by which conductive harness lines will adhere to a relatively non-conductive drum 5 by electrostatic attraction, when a voltage is applied between them. Alternatively, the harness lines 1 may comprise tapes (3) Figs. 4 and 5 (not shown) incorporating ferro magnetic material and an electrical coil (13), which, when energised, press the tapes against a ferro-magnetic drum. A plurality of drums may be provided, (Fig. 2, not shown) each controlling a set of harness lines, and the drums may have grooves (Fig. 3, not shown) in which the harness lines run. In a further embodiment Fig. 6, once the harness lines have been lifted by the drum 5, they are retained. in the raised position by an electromagnet 27 which acts on a coil or leaf spring 25 to which the end of the harness line is attached. The motion may be controlled to provide a travelling wave shed.