GB445489A - Improvements in incandescent electric lamps - Google Patents

Abstract

445,489. Two-part couplings. DEZSOE, Z., 13, Valentines Road, Ilford, London. Nov. 6, 1934, No. 31875. [Class 38 (i)] A multiple-filament lamp is provided with a remov able strip-like conducting member d of length sufficient to bridge between twc spaced contacts on the end face of the cap, the under side of the conducting member being provided with an insulating layei f, and one end being provided with a depending member e adapted to fit into a socket formed in one or both of the contacts b, c, so that when the member d is connecting a lampholder contact to a selected filament contact the other filament is positively insulated. The Figure shows a bayonet cap construction, with a third contact on the end face connected to a leading-in wire a which is common to both filaments. The filaments may be connected in parallel by removing the insulation from the underside of the conductor d. In a modification one contact only is socketed to receive the securing pin at the end of the conducting strip, so that on the burning-out of the filament connected to that contact it is necessary to remove the insulation from the conducting-strip to enable the end of the latter to bear upon a flush contact connected to another filament. In a further modification the conducting strip has a securing-pin at each end to engage within corresponding sockets in the cap contacts, these pins being of unequal lengths and the shorter being provided with removable insulation which keeps the associated filament out of circuit until required.