Venetian blind operation

Claim 1

IN A DEVICE FOR AUTOMATICALLY OPENING AND CLOSING A VENETIAN BLIND, THE COMBINATION COMPRISING: A VENETIAN BLIND INCLUDING A PLURALITY OF SLATS AND A PADDLE RETAINED IN SUBSTANTIALLY SPACED PARALLEL RELATIONSHIP BY STRAP MEANS, DIFFERENTIAL GEARING MEANS, FIRST AND SECOND DRIVING MEANS HAVING THEIR RESPECTIVE OUTPUTS CONNECTED TO SAID DIFFERENTIAL GEARING MEANS, SAID FIRST DRIVING MEANS IMPARTING MOTION TO SAID DIFFERENTIAL GEARING MEANS IN A COUNTERCLOCKWISE DIRECTION, SAID SECOND DRIVING MEANS IMPARTING MOTION TO SAID DIFFERENTIAL GEARING MEANS IN A CLOCKWISE DIRECTION, A SHAFT FIXEDLY CONNECTED TO AND DRIVEN BY SAID DIFFERENTIAL GEARING MEANS AND CONNECTED TO SAID PADDLE OF SAID VENETIAN BLIND, SAID DIFFERENTIAL GEARING MEANS DISPLACING SAID SHAFT IN A CLOCKWISE OR A COUNTERCLOCKWISE DIRECTION AT A SPEED WHICH IS THE DIFFERENCE BETWEEN THE MOTION IMPARTED TO SAID DIFFERENTIAL GEARING MEANS BY SAID FIRST AND SAID SECOND DRIVE MEANS, SAID SHAFT DISPLACING SAID PADDLE, SAID PADDLE AND SAID STRAP TRANSLATING SAID ROTATIONAL MOTION OF SAID SHAFT TO VERTICAL MOTION THEREBY OPENING AND CLOSING SAID SLATS OF SAID VENETIAN BLIND, PIN MEANS CARRIED BY AND ROTATABLE WITH SAID SHAFT, AND A SWITCH MEANS ACTUATED BY SAID PIN MEANS AFTER DETERMINED DISPLACEMENT OF SAID SHAFT IN SAID COUNTERCLOCKWISE DIRECTION SO AS TO DE-ENERGIZE SAID FIRST DRIVE MEANS.