| 摘要 |
<p>The mounting may be for a preset bell assembly inside the telephone instrument case. The bell assembly is built up on a board (5). At its fixing points the board has holes (6), for screws (9), which are surrounded on both sides by a convex rim (7,8). The telephone base (1), typically an injection moulding, has bosses (2) with tapped holes (4) for the fixing screws (9). These bosses are at an angle to the vertical to facilitate the moulding operation. When the board and base are assembled, the screw head bears on one side (10) of the upper rim (7) whilst a diametrically opposite point (11) on the lower rim (8) bears on the top of the boss (2). This feature gives free clamping of the board (5), and thus will not cause any movement in the bell assembly after the latter has been set up and locked.</p> |
