GB854305A - Improvements in and relating to the manufacture of electronic tubes and the like - Google Patents

Abstract

854,305. Making electronic and like devices; heating discharge tube tubulations by electric resistances. PHILCO CORPORATION. Nov. 17, 1958 [Nov. 18, 1957], No. 36889/58. Classes 39(2) and 39(3). Apparatus for tipping off the exhaust tubulation of an electronic tube or other device comprising an evacuated envelope from part of which adjacent the exhaust tubulation extends a series of leads or pins, comprises a body having an opening to receive the tubulation, means for heating the tubulation located in the opening, further apertures in the body for receiving the pins and heat shielding means between the heating means and the latter apertures. In the form shown, a cathode ray tube having a neck 14, Fig. 3, accommodating the electron gun structure and provided with pins 16 in a circular pattern around the exhaust tubulation 20, is mounted on a tipping off oven 22 consisting of an outer shell 28 of refractory insulating material such as pressed asbestos having a core 30 of refractory material such as ceramic. The core 30 has a central passage 33 aligned with a passage 34 in the shell 28 and a series of recesses 35 to receive the pins 16. Between the recesses 35, the inner surface of the core is scalloped to receive flattened resistant elements 38 connected in series by means of members 40, Fig. 4 arranged alternately on opposite ends of the core 30. A heat reflective porcelain coated plate 44 is mounted between the oven 22 and the base of the neck 14 to protect the glass seal of the pins 16 from the heat of the oven. In a modified arrangement, Fig. 7 (not shown), the opposite ends of adjacent elements are connected by ribbon like members passing over the outer surface of the core.