| 摘要 |
PURPOSE:To enable a tapping screw to be easily driven by a method wherein a prepared hole is formed into an ellipse whose semicircle has an effective diameter of the prepared hole, and effective diameter sides of the prepared hole are arranged at opposed positions respectively about a center inner diameter as a boundary. CONSTITUTION:A boss 22b and vertical pressing pieces 22c and 22d which serve also as butting pieces are molded in an integral piece and provided to a component mounting face of a frame 22. A prepared through-hole is provided to the boss 22b for a tapping screw, where the prepared hole makes a semicircle serve as an effective part and the upper and the lower effective part of the prepared hole are arranged on the right and the left respectively about a center inner diameter as a boundary. When a printed board 5 or the like is fitted to the molded frame 22, a tapping screw 6 is driven into the prepared hole provided to the boss 22b tapping it as making a fitting hole provided to the printed board 5 serve as a guide. As the effective bore of the prepared hole is a semicircle provided on the right and the left at its upper and lower part respectively, the resistance to tapping is made half. By this setup, a force required for driving the tapping screw 6 is made half, so that an operator can easily drive a screw even if the screws to be driven increases in number. |
