| 摘要 |
Installation box comprising a housing and a ring, wherein the housing is provided with a bottom wall and a cylindrical circumferential wall that is upright from the bottom wall and has a centre line, wherein the circumferential wall comprises a circular circumferential edge that faces away from the bottom wall and bounds an opening of the housing, wherein the ring is provided with a circular ring body, wherein the ring via a helical transmission along a helical path engages onto the inside of the circumferential wall, wherein with respect to the housing the ring can be rotated about the centre line of the circumferential wall in a first direction of rotation and a second, opposite direction of rotation, wherein the helical transmission is adapted for per revolution in the first direction of rotation moving the ring parallel to the centre line to a low position and wherein the helical transmission is adapted for per revolution of the ring in the second direction of rotation moving the ring parallel to the centre line to a high position. |
