GB327480A - Improvements in electric lighting fittings - Google Patents

Abstract

327,480. Engineering & Lighting Equipment Co., Ltd., and Bird, W. Jan. 17, 1929. Cut-out arrangements. - In safety lighting fittings of the kind wherein the contacts H of bulb-holder are held in contact with the supply terminals C by the globe and are adapted to be forced out of contact to break the lamp circuit by a spring 0 when the globe S or the bulb G is broken, the contacts C, H are enclosed in an airtight sleeve or bellows diaphragm Q attached to the relatively movable parts B, E that carry the contacts. In the construction shown in Fig. 1, the globe is forced into gastight contact with the plate K that carries the bulb-holder by means of a guard V adapted to screw into the casing A of the fitting, a resilient block X carried by a swivel Y, Fig. 3, being interposed between the guard and the globe, or the guard may be pivoted to the casing and the swivel replaced by a screw. In its contact making and breaking positions the plate K makes gastight engagement with internal flanges N, P respectively. The plate is guided by pins R. In the construction shown in Figs. 3 and 4, the globe is secured by clamps F<1> to a piston A<1> having a clearance in the casing A for the passage of gas from a broken bulb, so that the gas is cooled before it escapes from the fitting; holes Z are also provided. In the construction shown in Fig. 4, the part of the piston that carries the bulb-holder is separate from the part that carries the globe and is separately controlled by an additional spring D<1> so that the lamp circuit may be broken if either the globe or the bulb be damaged. In this case the contacts C, H are held in engagement by a spring E' interposed between the globe and the bulb.