| 摘要 |
This relates to means for effecting positive and sustained positioning of a heating element within an end-emissive cathode structure for utilization in a cathode ray tube electron gun. The orientation means is in the form of at least one heater positioning device located between a fixed heater support means and a connective extremity of the cathode heating element. The heater positioning device is formed of a bilaminate metallic material of predetermined flexure performance shaped to have an upper attachment portion at one end and a lower attachment portion at the opposite end thereof with acutely curved bend of bilaminate strip forming a partial loop of the material therebetween. Such bilaminate material comprises a first lamina of an active metallic alloy contiguously bonded along a common interface to a second lamina of a passive alloy material. The active alloy portion, upon being subjected to a predetermined temperature during tube processing, undergoes a metallurgical phase transformation effecting a volume change therein. The definite modification of the shaping of the positioning device thus effected exerts positive and sustained positioning of the heater element within the cathode structure in a manner to provide uniform spacing between the end of the heating element and the closure portion of the cathode.
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