GB412053A - Improvements in suspended lamps for shop lighting and like purposes - Google Patents

Abstract

412,053. Suspended lamps. HOLOPHANE, Ltd., Elverton Street, Vincent Square, London. July 31, 1933, No. 21487. Convention date, Feb. 9. [Classes 75 (ii) and 75 (iii).] A suspended lamp, particularly suitable for the illumination of shop interiors, comprises a multiple part envelope divided on an inclined median plane, that part of the envelope above the plane of division comprising a reflector for returning light on to the part below the plane of division, which lower part accommodates the light source and is in the form of a hemispherical or partly hemispherical translucent transmitter with an optical axis substantially normal to the plane of division for producing an obliquely and downwardly projected flood of light of controlled spread and uncontrolled light of comparatively low intensity through a substantially wider angle for general illumination. The upper part may be opaque or translucent and it may be in the form of a prismatic or other reflector or it may be fitted with a reflector. The lower part may have its bottom portion flattened, it may be made of opal or other diffusing glass, but it is preferably made of prismatic glass and several arrangements of refracting prisms and co-operating diffusing flutes are described and illustrated in the Specification. A plain or ornamental, opaque or translucent, annular band may be secured around the envelope along the plane of division, or a visor-shaped shield may be attached to one side of the envelope and be made of translucent material and used for advertising purposes. In the form shown, the envelope comprises a glass hemisphere 27 hinged to a metal hemisphere 26 which is carried by a tubular stem S, and the electric lamp bulb 28 is arranged with its filament 30 at the centre of a spherical reflector 29. A strap 28a is riveted to the inside of the member 26 and has holes 28b, 28<c>, 28d, and 28<e> spaced opposite knock-outs 26b, 26<c>, 26d, and 26<e> in the member 26, so that by changing the hole and corresponding knock-out engaged by the stem S the angle of inclination of the plane of division also is changed. Specification 243,559, [Class 75 (ii)], is referred to.