gasgefuellte electrical gluehlampe, especially with a screen (gasgefuellte gluehlampe, e.g. car lamp that, price of getter

摘要

797,207. Electric incandescent lamps. EGYESULT IZZOLAMPA ES VILLAMOSSAGI R. T. Nov. 25, 1954 [Dec. 5, 1953] No. 34203/54. Class 39(2) A selected part of the interior surface of an elec tric incandescent lamp bulb is provided with an opaque coating having a substantially sharply de fined boundary by mount ing within the bulb a metal platform or cup 1( Supporting a quantity of getter metal which is volatilized, e.g. by high frequency induction or by heat from a separate heating spiral within the lamp, the platform or cup 10 being shaped to direct the volatilized metal on to the part to be coated, a disc 14, preferably of mica, being mounted beneath the plate or cup for screening the remaining part of the bulb from deposition of the getter metal. The bulb is exhausted prior to the heating of the metal plate, and the process may be applied to a normal lamp making operation by disconnecting the bulb from the exhausting apparatus during the volatilization of the getter. The example shows part of a projector lamp with the upper end of the bulb provided with an opaque internal coating. The coating may consist of a single getter metal or a plurality of metals such as barium, iron, or titanium, at least one of which acts as a getter. Getter metals. which are difficult to volatilize may be supported on a thin metal disc relatively smaller in size than the plate or cup 10 in order that they may be heated more readily by high frequency current. Specification 695,081 is referred to.