GB189912950A - Improvements in the Manufacture of Incandescing Media for Lighting Purposes. - Google Patents

Abstract

12,950. Langhans, R. June 21. Incandescent gas &c. lamps.-Mantles possessing a characteristic appearance, and combining mechanical strength in the hot state with elasticity and resistance to shocks and jars in the cold state, are prepared by impregnating fabric in the following or somewhat similar solutions : (a) 5443 grammes of thorium nitrate, 0À690 gramme of zirconium nitrate, 0À612 gramme of crystallizable sodium silicate, 0À138 gramme of cerium nitrate, 0489 gramme of beryllium nitrate, and 0À380 gramme of boric acid ; (b) the same ingredients as in (a), but in the following respective proportions in grammes, 6À804, 0À172, 0À153, 0À087, 0À164, and 0À108. The fabric, before impregnation, should have twice the length and width of the mantle to be produced, and meshes of double the width of those generally used, to allow for the shrinkage which takes place when the mantle is incinerated. Mantles prepared from solution (a) contain insufficient thorium to give good illuminating results, but are used as skeletons for receiving any desired special light-emitting compositions. The beryllium salt and the boric acid may be dispensed with, the former being employed to prevent the mantles from becoming brittle at low temperatures, while the presence of the latter renders it unnecessary to supply gas at high pressure to the incinerating-flame. When the beryllium salt is employed, the proportions of thorium and cerium salts in the impregnating- solution may be increased, such a solution containing the ingredients specified in solution (a) in the following respective proportions in grammes, 15À240, 0À110, 0À107, 0À196, 0À164, and 0À064.