| 摘要 |
<p>PURPOSE:To prevent inferior electric contact by crowning a screw base on a cylindrical portion, forming a cut groove along the axial direction, inserting a lead wire through this cut groove, and connecting the lead wire to the screw base. CONSTITUTION:A circular reinforcement ring 30 is fitted in an opening end in a cylindrical portion 15 protruded from a cover 2. The ring 30 is provided with a flange 31 to be superposed on the opening end face of the cylindrical portion 15 and a fitting portion 32 to be fitted to an opening portion of the cylindrical portion 15, and formed with an introduction hole 33 for leading a lead wire 27b in the central portion. When such a ring 30 is fitted to the opening portion of the cylindrical portion 15, each groove space of cut grooves 17, 17 is maintained, and mutual approaching for deformation of walls of the cylindrical portion 15 is eliminated. With this constitution, even in the case where a lamp and ballast are heated during lighting and the heat is transmitted to the cylindrical portion 15 via the cover 2 to raise a temperature, a top end portion of the cylindrical portion 15 is prevented from contraction in the diameter so that loosening of the base 7 never occurs.</p> |
