Abstract:
A high pressure sodium vapor lamp arc tube comprising a tubular envelope of alumina ceramic having end closures supporting thermionic electrodes and containing a filling of sodium-mercury amalgam in excess of the quantity vaporized. In the smaller sizes of lamps from about 300 watts down to 50 watts, the arc tube bore has an important effect on efficacy, and a correlation exists between lamp voltage drop and optimum bore for a given power input. A bore of 5.5 millimeters is near optimum for a 150 watt lamp operating at a lamp voltage drop of 58 volts, and is also suitable for a 250 watt lamp operating at a lamp voltage drop of 98 volts.
Abstract:
The adherence of an optically reflective coating of zirconium oxide on a fused silica discharge tube surface is improved severalfold by an intermediate adhesion layer consisting of very fine aluminum oxide and boric oxide powders. The adhesion layer is first applied and dried, the zirconium oxide coating is applied, and the quartz tube is then lehred at a temperature greater than 460*C., the melting point of boric oxide. The improved coating strength permits the use of a thicker layer of zirconium oxide for higher optical and thermal reflection.
Abstract:
An improved mounting structure in a high intensity discharge lamp accommodating thermal expansion of a ceramic arc tube mounted on a support frame within an outer vitreous envelope. One end of the arc tube is rigidly fastened to the frame, while the other end is secured by an axial lead wire which extends from a ceramic plug through a single close-fitting loop in a transverse support wire and a flexible conductor provides the electrical connection. Close fitting round wires are used for the axial lead and the transverse support, permitting one to slide within the other without seizing or binding and without rattling.
Abstract:
AN IMPROVED SEAL OR BOND BETWEEN A REFRACTORY METAL AND A TRANSULCENT ALUMINA CERAMIC BODY USES A GLASSY SEALING COMPOSITION CENTERED ON 36.4 WEIGHT PERCET CAO, 45.0 WEIGHT PERCENT A1203, 4.7 WEIGHT PERCENT MGO, AND 13.9 WEIGHT PERCENT BAO. THIS COMPOSITION PERMITS A LOWER SEALING TEMPERATURE (1410*C.), AND A WIDER RANGE ($50*C.) IN
SEALING TEMPERATURE WITHOUT DELETERIOUS EFFECTS, THAN PREVIOUSLY KNOWN COMPOSITIONS.