摘要 |
A device for mechanically opening and closing a door comprising two door portions (2, 3), where the movement of the door portions (2, 3) relative to each other is controlled by at least one linkage (6), which at fully opened door assumes a self-braking position. The device comprises a drive means (22), which is connected to one door portion (2), and on the drive shaft of which, which is capable to effect rotary movement in two directions, a drum (29) is located, two wire strands (23, 24), which are connected to the drum (29), guide wheels (26-28) for the wire strands (23, 24), a spring means (25) connecting the wire strands (23, 24), and a catch member (21) attached to the linkage (6). The wire strands (23, 24) are so connected to the drum (29) that at rotation of the drum (29) in one direction one wire strand is wound off the drum while the second wire strand is wound on the same, and vice versa. In the final phase of an opening movement of the door the catch member (21) actuates one wire strand (23) so as to bend it. In the initial phase of a closing movement ofthe door the bent wire strand (23) is stretched, whereby the linkage (6) is caused to move out of its self-braking position. The drum (29) moves at the opening and closing of the door along an arc, and the spring means (25) renders it possible that this can proceed without wire break. |