GB1150441A - Improvements in and relating to Cathode Ray Tube Apparatus - Google Patents

Abstract

1,150,441. Cathode-ray tube mountings. SPECTO AVIONICS Ltd. 23 June, 1966 [23 June, 1965], No. 26567/65. Heading H4T. A mounting for a display cathode-ray tube comprises a structure of insulating material having cylindrical and conical portions (7, 8, Fig. 1), for receiving the tube 1, which may be withdrawn face first when a retaining apertured cap 9 is unscrewed, together with spring- urged contact means 12 which, when the tube is in position supplies E.H.T. via conductor 15 to a terminal contact 11 on the conical portion of the tube. In this embodiment angular location of the tube, to ensure registration of contacts 11, 12, is effected by a peg 16 secured to the neck of the tube and a locating slot 17 formed in the mounting structure. In a second embodiment correct angular location is ensured by means of a resiliently mounted socket (21, Fig. 3), co-operating with the normal pin contacts at the end of the tube neck and the mounting structure is modified by the provision of two spring-loaded plungers 24, 25, Fig. 2, to provide, with contact 12, a resilient three-point bearing for the tube. The mounting structure is further modified by the provision of an insulating sleeve 29 which prevents spring 14 from overextending when the tube is removed and by cut-out portions 26, 27, 28 which reduce the weight of the structure. The assembly further includes a focusing magnet (20) and a mild steel screen (23). The facility of withdrawing the tube face first (e.g. for maintenance or repair) is advantageous when it is installed in positions (e.g. in aircraft) where the neck end is not readily accessible and by making the mounting structure a close fit about the tube the leakage resistance between the E.H.T. contact 12 and the deflection coils 18 is kept at a high value.