GB429424A - Improvements in or relating to electric incandescent lamps - Google Patents

Abstract

429,424. Electric incandescent lamp bulbs with internal reflectors. LAMPE YVEL, AUTO-LAMPE, & CIE ANCIENS ETABLISSEMENTS L. LEVY ET A. MONNIER, 11, Rue Torricelli, Paris. Oct. 24, 1933, Nos. 29450 and 29451. Convention dates, Nov. 3, 1932 and Nov. 28, 1932. [Class 39 (ii)] In a lamp suitable for motor car headlights having two filaments, one of which co-operates with an internal reflecting screen, at least that half of the bulb which is turned towards the opening of the reflecting screen s<1>, Fig. 3, is provided with corrugations b<3> following the lines formed on the surface of the bulb by rays passing from the main filament which, on reflection by the parabolic reflector co-operating with the bulb, form vertical straight lines in a plane perpendicular to the axis of the reflector. Rays scattered by the corrugations form plane pencils which, after reflection in the parabolic reflector, lie substantially in horizontal planes. The other half of the bulb may be profiled in the above-named manner or by corrugations produced from non-vertical parallel lines in a similar manner. Alternatively, diffusing lenses a may be provided. The front portion of the bulb may be provided with concentric circular corrugations g. Clear zones e are left to facilitate centring of the internal members during manufacture. The Specification as open to inspection under Sect. 91 comprises also the use of two superimposed sets of corrugations making angles of 45‹ or 90‹ with each other. This subject-matter does not appear in the Specification as accepted. Reference has been directed by the Comptroller to Specification 404,223.