摘要 |
There is disclosed a viewing panel unit, comprising: a first panel and a second panel; a drive mechanism for moving the first panel relative to the second panel; and an abutment member mounted so as to have a fixed spatial relationship relative to the second panel, wherein: the first panel comprises a coupling member; the drive mechanism comprises a drive member configured to engage with the coupling member such that rotation of the drive member imparts a linear motion to the first panel via the coupling member; and the drive mechanism is configured such that a first impact surface of the drive member is brought into contact with a surface of the abutment member to stop the drive member when the drive member is rotated through a maximum angle in a first sense. |