US Patent 7828041 Manually activated roll-up window shade

A roll-up sunroof shade is provided that has two guide rails in addition to the tensioned shade element. A push element runs in each guide rail. Each push element is driven with a positive fit via a separate drive gear. For manual activation of the shade element, the rotational movement of the wind-up shade is transferred to the drive gears, and thus to the push elements, via a gear arrangement. In contrast, during retraction, the force acts from the push elements onto the wind-up shaft via the drive gears in order to generate the necessary rotational movement of the wind-up shaft.