| 摘要 |
908,096. Discharge tubes. SYLVANIA ELECTRIC PRODUCTS Inc. Feb. 22, 1961 [March 11, 1960 (3)], No. 6534/61. Class 39 (1). [Also in Group XXII] An indirectly-heated cathode 31 (Fig. 1) of compressed sintered metal powder encloses a double interwound spiral of coiled heater wire 33 having a ceramic coating and is suspended across an opening in an insulating support 37 by lead wire connections 41, 45 to the two projecting ends of the heater and to the cathode body. As shown, the support 37, Fig. 4, comprises an apertured ceramic disc mounted by means of metal cylinders 63, 57 in a grid 29 of a cathode-ray tube. Leads 41, 45 pass through apertures in disc 37 and are flattened and bent to lie in grooves 53 in the surface of the disc, leads 41 being connected directly to the uncoated portions 39 of the heater and lead 45 being bent downwardly to engage a tab 43 extending axially from the cathode body. Alternatively, leads 41, 45 may extend through radial apertures in disc 37. Emissive material 65 may be applied to the cathode 31 after it has been mounted relative to cylinders 63, 57. The cathode may be formed by compacting equal portions of metal powder on either side of the heater and sintering, Figs. 13-22 (not shown). Suitable dimensions for the cathode assembly are given. |
