Patent GB-191203590-A (GB)
Title: Improvements relating to Electric Switches and the Conductor Connections thereto.
Inventor: SHELDON HARRY CECIL
IPC: H01H9/54
Filed: 1912-02-13
Granted: 1913-02-13
Abstract: 3590. Sheldon, H. C., [Sachsische Gruppenwechselschafter Ges.]. Feb. 13. Lighting systems.-In a multiple-control switching - arrangement for lamps, each switch is provided with h two movable contacts and two, three, or four fixed contacts so connected to the lamp terminals and supply mains that the former may be connected to the positive or negative main, or one to the positive main and one to the negative main. In the arrangement shown in Fig. 1, two lamps c, d are controlled by either of two switches A, B, each having movable contacts f, f<1>; g, g<1>, and fixed contacts h, i. The movable contacts f, f<1> are connected to the positive main, and the movable contacts g, g<1> to the negative main, and by revolving one or both switches the lamps c, d are controlled. In a three-point control arrangement, as shown in Fig. 11, the third switch C has two movable contacts a, b and four fixed contacts h, i, k, l. In the modification shown in Fig. 13, each switch is provided with two movable contacts a, b, each of which has three contact surfaces f, f<1>, f<2>, g, g<1>, g<2> adapted to engage three fixed contacts h, i, k connected to the lamp terminals. In the modification shown in Fig. 15, each switch is provided with four fixed contacts h, i, k, l connected in pairs to the supply mains, while the terminals of the lamp c are connected to a movable contact of each switch; in a further modification, the movable contact of one switch is connected to the positive main, and the movable contact of the other switch is connected through the lamp c to the negative main. In the modification shown in Fig. 17, the fixed contacts l, i of the switches A, C are connected to the positive main, and the fixed contacts k, h to the negative main. The fixed contacts l, i of the switch B are connected to the movable contact a of the switch C, and the fixed contacts h, k to the movable contact b of the switch C. In a further modification, the movable contact a of one of the extreme switches is connected to the positive supply main, the movable contacts of the intermediate switch to the fixed contacts of the extreme switch, and the movable contact of the other extreme switch to the negative main through the lamp to be controlled. In the modification shown in Fig. 19, the fixed contacts h, i of each switch are connected to the positive main, and the fixed contacts l, k to the negative main, the movable contacts of the switches being connected to the terminals of the lamps to be controlled. The switches employed may be of the rotary or rectilinear type, but the form preferred is shown in Figs. 25 and 26, and consists of a drum n of insulating-material mounted on a rotary spindle m and carrying contacts a, b, the former being divided to form contacts f, f<1> and the latter to form contacts g, g<1>. The contact a is connected to the terminal r through a spring q and ring o, and the contact b to the terminal s through a spring t and ring p. The fixed contacts h, i are connected to the external circuit by terminals u, v.