| 摘要 |
The bottom plate (14) has two holes for screws and has two protuberances (24,26). The bottom plate is at least partly covered by a top plate which has an elongated middle part and side attachments possessing elongated holes. The holes are on the centre line of the bottom plate. One hole has an extension like a straddling dowel; the other hole has a pre-mounted screw in its protuberance. |
