GB511615A - Improvements in directional lighting fittings - Google Patents

Abstract

511,615. Street &c. lamps. GENERAL ELECTRIC CO., Ltd., and BEGGS, S. S. April 5, 1938, No. 10432. [Class 75 (ii)] A street lamp or like directional lighting fitting of the kind which produces a maximum light intensity in a direction highly inclined to the vertical is provided, below the source 4 with a shallow bowl 1 bearing two sets of prisms 2, 3, one set adapted to bend the light towards the vertical line passing through the source and the other set adapted to bend the light away from a vertical plane passing through the source and perpendicular to the axis of the street. Figs. 1 and 2 show views, at right angles to each other, of one construction, the sets of prisms 2, 3 having their edges lying in parallel vertical planes ; the vertical planes of the set 2 are parallel to the street axis, while those of the set 3 are perpendicular to the street axis. Fig. 4 shows a modification in which the prisms 2 have concentric circular edges, the prisms 3 being arranged in the same relation to the street axis as in Figs. 1 and 2. The two sets of prisms may be on the same or opposite faces of the bowl 1, or the latter may be constituted by two portions each carrying one set of prisms. Specifications 351,761 and 420,922 are referred to.