switch bar (swichbar)

1. The bar or rod that connects the movable rails of a switch with a switch-lever at the side of the track.-2. The movable bar of a switch by which an electric circuit is made or broken. switchboard (swich'bord), n. A device by means of which interchangeable connections can be established readily between the many circuits employed in systems of telegraphy, switch-bar or -rod (that nearest the point is called the front rod); e, switch-stand, with butterfly-signal and lamp. In fig. 4 the switches are shown as arranged at a cro ing for shifting a train from one track to another in either direction. The outer rails in point-switches are full rails and rigidly spiked to the ties, while the inner are movable and taper to a point (whence the term split, as applied to them, is derived). In stub-switches the rails are full, and the rails of the main track adjacent to the branch as well as the branch rails are rigid, while the movable rails are on that part of the main track which meets the branch. The double-slip switch is simply composed of four point-switches. been invented to make switches more safe, to render them automatic (as at the terminus of a line where the engine is to be shifted to the other end of a train), to render them interlocking, so that no one switch of a system can be opened without locking all others, and to connect them with signals and annunciators. Switches in one yard are now commonly controlled by means of long levers with a central tower from which one switchman can see and control them all. (b) In teleg., a device used to make or break a circuit, to join two lines of wire or a main wire with a branch wire, or to connect any telegraph, telephone, electric-light, or electric-signal wires in any manner. The most simple form of switch is a lever pivoted at one end and connected with one circuit, and, by its movement laterally, used to connect that circuit with one of several others. Another simple form, called the plug- or peg - switch, consists of a metal plug or peg that may be inserted in openings or spaces between metal rods connected with different circuits. The peg serves as a bridge to join different circuits. The peg may also be connected with a short piece of flexible wire, the wire serving as a bridge for the current. By moving the peg from place to place on the switchboard, the wire serves as a switch to divert the current from one line to another. See switchboard. 3. In some forms of gas-burner, a key for controlling the amount of gas allowed to pa through.-4. The act of operating a switch: as, to make a flying switch. See phrase below. -5. A quantity of long hair, secured together at one end, worn by women with their own hair to make it look thicker. Jute or yak is sometimes used with or in place of hair, being cheaper.- Flying switch, a switch operated or effected in such a way, while a train is in motion, as to send different parts of the train (previously disconnected) along different lines. Pole-changing switch. Same as pole changer. (See also pin - switch, replacing -switch.)