(under subclass 313) Systems wherein the system includes a switching system for controlling the connection of the load devices to the source of supply, the switching system including a primary or master switch and a secondary switch, the primary and the secondary switch each having two circuit closing positions, the source of supply being adapted to be connected to the primary switching means, the primary switch selectively closing the circuit to either the secondary switch or another circuit, the secondary switch means selectively closing either of two circuits so as to connect either of these two circuits to the source of supply through the primary and secondary switches, the circuits closed by the primary and the secondary switches in each of their operated positions serving to close the circuit from the source of supply to at least one of the load devices, for example: [figure] [figure]
(1) Note. The circuits closed by the primary and secondary switch may be the circuit through which current flows to the load device, or may be the circuits supplying current to electrically controlled or operated switches, connected in the load device circuits, the electrically controlled or operated switch connecting the load devices directly to the source of supply for the load devices.
(2) Note. This subclass includes systems wherein there are only two load devices, a different one of the load devices being energized in each of the circuit closing positions of the secondary switch and one of the load devices being energized when the primary switch is in the circuit closing switch positions which does not include the secondary switch.
(3) Note. This subclass includes systems wherein there are three or more load devices, a different one of two of the load devices being energized in each of the circuit closing positions of the secondary switch positions and the third load device being energized when the primary switch is in the
circuit closing position which does not include the secondary switch.
(4) Note. The systems in this subclass are designed to permit the selection of the load device to be energized from the group of load devices controlled by the secondary switch means prior to the closing of the circuit to the secondary switch means by the primary switch means.
(5) Note. The systems in this subclass are often used to control stage and theater lights. SEE OR SEARCH THIS CLASS, SUBCLASS:
293, for pre-selectable regulating systems.
316, for switching systems under subclass 313 wherein the switching means includes a keyboard or pattern (perforated sheet).
317, and indented subclasses, for other systems under subclass 313 wherein there are three or more load devices.
320, and indented subclass, for other systems under subclass 313 having a plurality of switches in the supply circuit.
322, for other systems under subclass 313 provided with an alternate circuit closing switch.
SEE OR SEARCH CLASS
307, Electrical Transmission or Interconnection Systems,
38+, for plural load circuit systems having means for selectively connecting said load circuits.
