GB532078A - Improvements in sockets or holders for electrical lamps - Google Patents

Abstract

532,078. Two-part couplings. VORONIN, P. S: Aug. 16, 1939, No. 23623. [Class 38 (i)] A holder for a multi-filament electric lamp bulb comprises a socket rotatable relatively to a fixed base to operate a multiple switch by which the filaments of the bulb may be variably connected to the current supply. The bulb 1 has filaments 2, 3 which are connected to three contacts 5 in its base, and the bulb fits into a socket 7 provided with three spring contacts 6 which engage the contacts 5. The socket 7, which is of the kind described in Specification 397,687, [Group XI], has a rotatable base part 13 that fits into a second socket 9 provided with two spring contacts 14, 15 to which the current leads 16 are connected. The base 13 has a pair of contacts 10 which prevent a connection between the contacts 14, 15 and three contact plates 12 electrically connected to the contacts 6. Rotation of the socket 7 relatively to its base 13 provides a variable connection between the leads 16 and two of the three contacts 12, as described in the Specification referred to. The socket 9 is attached to a tube 23 secured to a base 24, and the socket 7 is attached by screws 21 to a tube 22 that encloses, and is rotatable relatively to, the tube 23. Thus the filaments 2, 3 may be, variably connected by turning the tube 22 relatively to the base 24. In a modification, the part 13 is attached directly to the tube 23.