Automatic stop for roller blinds - uses epicyclic gear trains rotating at slightly different speeds and requires coincidence of notches in their annuli to operate switches

摘要

The roller blinds have their drive motor mounted inside the roller and an electric contact operated by a lever through a gear train, also mounted inside the roller, to switch off the electric supply when the blind reaches the limits of its travel. A lever (25) is operated by two side-by-side epicyclic gear trains (9,12) rotating at slightly different speeds in order that it is only after a certain number of revolutions that notches which are cut in both the annuli (9a,12a) coincide and allow the operating lever to move and operate the push button (23) on a circuit breaker. The use of two levers allows operation at two different positions of the blind.