| 摘要 |
882,024. Electric immersion heaters. A.E.I.- HOTPOINT Ltd. May 6, 1960 [June 15, 1959], No. 20427/59. Class 39(3). In a sheathed wire electric immersion heater the header consists of an annular insulating member 4 having a screw threaded extension 5 through which the header is adapted to be secured to a mounting flange 20 or to the tank wall, the heating element 2 passing through openings in a metal plate 10 the sheath of 2 being hermetically secured to the metal plate 10, the plate 10 being clamped to an annular shoulder 13 formed within the screw-threaded extension 5 and a terminal block 11 is integral with the header. The heating element comprises a heater in an outer metal sheath with compacted refractory mineral insulation between. The annular insulating header 4 is of synthetic plastic, e.g. of superpolyamide type such as "nylon" (Registered Trade Mark) or of polyethylene known as "polythene" (Registered Trade Mark) and has a flange 6. The header and mounting flange 20 or tank wall have threaded portions engaging one another. The heating element 2 is welded or soldered to metal plate 10. The terminal block 11 is formed by moulding. A thermostat 3 is provided. There may be a plurality of heating elements. The metal plate 10 may be moulded within the header as in Specification 860,743. The header 4 and cover 7 have snap engagement as in Specification 874,851.
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