5190. Vandam, A., and Marsh, T. H. March 1. Couplings; switches. -Relates to switches for wall plugs &c., the switch being independent of the plug. Figs. 2, 3, and 4 show a construction for a wall plug having concentric contacts. The base 1 carries the central socket 3 and a sleeve 9 separated by an insulating-sleeve 12. On the part 3 is pivoted a lever 2, which is adapted, when in the 'on' position, to make contact with springs 6 connected to one terminal 5. The other terminal 7 is permanently connected to the sleeve 9. On inserting the plug, the circuit is made or broken by operating the lever 2.