GB253138A - Improvements in caps for multi-filament electric lamps and similar apparatus - Google Patents

Abstract

253,138. Hermont, G., and G³nzburg, G. June 4, 1926. Multiple-filament lamps; holders.-In screwcap multiple-filament bulbs of the kind wherein one filament e, Fig. 1, is connected to a central stud contact a, and another filament f to a concentric annular contact b on the cap, the contact b is in the form of a spring having a depending portion embedded in the insulation of the cap. A holder to accommodate this bulb is provided with two corresponding centre contacts c, d, Fig. 2, connected by leads k, m to an external switch for selectively lighting the filaments. The cap forms a contact common to both filaments, and is connected by a lead l to the switch. The Specification as open to inspection under Sect. 91 (3) (a) comprises also the following :- In the construction shown in Fig. 4 (Cancelled), one central contact 1 is tubular and the annular contact 2 is rigid and lies above the contact 1. When this bulb is inserted into an ordinary holder, contact is made only with the annular contact 2, lighting the filament BC. To light the filament AC, a stud 7, Fig. 6 (Cancelled), is passed through the contact 2 without touching, it and is inserted into the contact 1, an insulating washer 8 being fitted on the stud if it is not desired to light both filaments simultaneously. This subject-matter does not appear in the Specification as accepted.