GB860553A - Improvements in sealing means for electrical apparatus - Google Patents

Abstract

860,553. Sparking plugs. BENDIX CORPORATION. May 8, 1959 [May 29, 1958], No. 15912/59. Class 7(4)., [Also in Group XXXVI] In an electrical apparatus, the non-sticking sealing engagement of a member composed of elastomeric material with a rigid member is provided by coating the rigid member with polymerized tetrafluoroethylene. In a spark discharge device, layers 37 of the resin aredisposed on the surfaces of a ceramic member 20, on a metal compression ring 32, on the lower and inner side edges of a metal washer 28, and upon a limited area of the inner wall of a metal shell 11. A terminal 15 connected to the upper end of an electrode 16 is abutted by a terminal 21 affixed to a cable 17, and an annular rubberlike member 24 engages the insulation 19 of the cable. The member 24 engages the upper ends of the ceramic member 20 and a sheath of rubber-like material 22, and is pressed downwardly by a compression spring 25. A ferrule member 29 engages the upper end of the spring and is retained on a radio-shielding enclosure 11 by a nut 30. A further spring 35 holds a rubber-like sealing member 31 in compression between the top of a ceramic insulator 12 and the metal compression ring 32. The resin allows the parts to move freely with respect to each' other as required by their changes in dimension under varying temperature conditions and to be easily disassembled without damage. The resin also improves the insulating properties of the ceramic members. In a further construction, Fig. 3 (not shown), a coiled contact spring is urged into engagement with the electrode terminal by a larger coiled spring: Specifications 684,804 and 821,299 are referred to.