Device with counterweights and a vertically movable door plate for closure of a wall opening comprises traction elements which positively engage with pulleyes at least during a part of the door plate motion

摘要

The device incorporating counterweights (20) and a vertically movable door plate (10) for closure of a wall opening comprises traction elements (12) which positively engage (as a consequence of interlocking shapes) with pulleyes (14) at least during a part of the door plate motion.