GB359965A - Improvements in or relating to positive column discharge tubes - Google Patents

Abstract

359,965. Discharge lamps. WHITE, A. E., 5, Quality Court, Chancery Lane, London.-(Flexlume Corporation; 1100. Military Road, Tonamanda, New York, U.S.A.) June 30, 1930, No. 19822. ,Class 39 (i).] In alternating- current, positivecolumn, discharge tubes with an electrode at each end of a long tube 1, Fig.1, a hollow electrode 4, such as a cylinder open at both ends, is surrounded by, and contacts with, a hollow insulating body 5 defining a restricted or obstructed discharge path between the interior of the electrode 4 and the tube 1, this path being of less cross-sectional area than the main illuminating part of the tube 1, The obstruction is preferably an end 9 of internal diameter less than that of the electrode 4 but may alternatively be a cap 10, Fig. 3, with apertures 11 for the discharge. Disintegration of the electrode on to the tube 1 and absorption of gas thereby is thus avoided. The body 5 may be of glass and the electrode of foraminous material partially embedded in the glass to increase the flow of heat from the electrode. The body 5 may be supported by a flanged glass cylinder 7 or a glass sleeve 12, discharges to the lead 3a at the back of the body 5 being avoided in both constructions. Dischares to the lead inside the are avoided by offsetting the lead as shown into a position not in the axial centre of the discharge. Dimensions of the electrode structure, when the tube 1 is filled with neon at 8-10 mm., are given.