Roll-up window shade with reduced-friction drive
AssigneeBOS GmbH & Co. KG
InventorsMelf Hansen, Wolfgang Stark
Life of this patent
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Abstract
Two drive gears are provided as an extension of the guide rails for driving a roll-up window shade for a motor vehicle. The drive gears are coupled to the winding shaft in a rotationally elastic manner. The driving is carried out via a geared motor, which acts either on the gears or on the winding shaft. The positioning of the drive gears as an extension of the guide rails avoids the guide tubes used in prior art arrangements. Thus, the friction losses found in the prior art, which consume up to 80% of the drive force, are avoided. Furthermore, manufacturing is simplified because the connection tubes having a complicated shape are not needed.
Claims30
A roll-up window shade for motor vehicles comprising:
- a rotatably supported winding shaft;
- a shade having a first edge affixed to the winding shaft;
- a tension rod connected to a second edge of the shade spaced away from the winding shaft;
- two guide rails each extending on a respective side of the shade when the shade is an extended position, the two guide rails guide the tension rod in a positive-locking manner;
- two push elements each being conducted in a respective one of the guide rails, each push element carrying a gear-tooth system that acts on the tension rod;
- two drive gears arranged at first and second ends of the winding shaft, each drive gear being allocated to a respective one of the push elements, wherein the push elements are operatively arranged between the drive wheels and the tension rod;
- an electric drive motor;
- and
- a spring compensating element for compensating for differences in the length of the shade as it is extended as compared to the corresponding length of travel of the push elements in the guide rails.
Dependencies are inferred from the claim text.