| 摘要 |
<p>645,168. Heavy-current switches; actuation of switches. CARNEGIE - ILLINOIS STEEL CORPORATION. April 27, 1948, No. 11549. Convention date, Feb. 20, 1948. [Class 38(v)] A switch for reversing the polarity of a load supplied with direct current of the order of 10,000 amps as is used in the electrolytic cleaning of ferrous strip comprises a slightly tapered drum 10 having substantially semicylindrical copper contacts 21, 22 insulated from each other by a board 23 and recessed to accommodate respectively insulating segments 29, 30. The drum is axially and angularly movable by its shaft 11 and is normally supported by correspondingly tapered contact shoes 12 ... 16, the shoes 12, 13 being connected by termihals 31, 32 and bus-bars 39, 40 to the supply. The load busbar 50 is connected by terminal 45 to the shoe 14 and by a jumper bus-bar, Fig. 3 (not shown) and terminal 47 to the shoe 15, the load bus-bar 51 being connected to the shoe 16 through a jumper bus-bar 52 and terminal 46. When the drum is in the position shown the shoe 15 engages the insulating segment 30, the side 50 of the load is connected to the side 39 of the supply, and the side 51 connected to the supply side 40. On clockwise rotation of the drum through about 45 degrees the shoe 14 engages the insulating segment 29 and the load polarity is reversed. The drum shaft 11. is connected. at its lower end to the piston rod of a reversible fluid pressure motor, Fig. 2 (not shown) and is guided at its upper end in a sleeve 18, the drum being normally held against the shoes by a compression spring 20 and being raised from that position, prior to rotation, by the motor. For rotating the drum, a reversible fluid pressure motor 54 is connected by a link 56 and ball and socket connections 57, 58 to one end of the drum. The motors are controlled by valves operated by solenoids, Fig. 6 (not shown) such that on pressing a button the drum is raised, rotated, and then lowered, this sequence of events being automatic and produced by a control circuit, Fig. 5 (not shown).</p> |
