Roller blind with perforated band drive

Abstract

A drive arrangement for roller blinds of motor vehicles is provided. The drive arrangement includes a housing that contains a chamber for accommodating a spring steel band that is pre-formed in a spiral shape in a similar manner to a clockwork spring. The spring steel band is equidistantly perforated in the longitudinal direction and moves over a drive gear that is configured similarly to a barbed wire and driven by a geared motor. The projections of the drive gear engage with the holes of the spring steel band.

Description

FIELD OF THE INVENTION[0001]This invention relates to roller blinds for motor vehicles and more particularly to a drive arrangement for such roller blinds.BACKGROUND OF THE INVENTION[0002]Remote-controlled window shades in motor vehicles require a motorized drive. Due to the fact that the roller blind consists of a non-rigid material, the roller blind cannot be pushed so that the far edge of the roller blind relative to the winding shaft must be moved away from the winding shaft in suitable fashion.[0003]This is the reason that the winding shaft for the window shade is pre-stressed in the wind-up direction of the roller blind by means of a spring drive using arrangements that are known from the state of the art. In order to unwind the roller blind in front of a window, the roller blind is provided with a pull rod having ends that are guided in guide rails. The guide rails simultaneously serve for guiding in a buckle-free manner toothed racks that have teeth all around their surface....

AI Technical Summary

Benefits of technology

[0005]In view of the foregoing, a general object of the present invention is to provide a drive arrangement for window blinds in motor vehicles that has a very compact design.

[0008]As a result, the idle segment of the spring steel band used for moving the roller blind is wound up spirally and therefore can be accommodated in a space-saving manner. All that is necessary to accommodate the idle segment is a small chamber in the immediate vicinity of the gear housing of the drive motor. This makes it possible to eliminate the additional installation steps for installing the idle tubes required by the state of the art.

[0013]A guiding arrangement may be provided in order to guide the spring steel band without buckling when it is subjected to pressure. A guiding arrangement that causes a general extension of the working segment of the spring steel band is also practical when the spring steel band is subjected to a tensile load.

[0017]If the wrap angle is kept extremely small, the new drive arrangement can provide an overload protection or an anti-catching protection. For example, if the pressing mechanism for the spring steel band on the driving gear and the projections are designed accordingly, the projections are able to push back the spring steel band and thereby disengage from the holes of the perforation in order to limit the thrust and thus realize an anti-catching protection. Advantageous conditions can be achieved if the projections are configured in the shape of a spherical cap, a cone or a truncated cone.

Problems solved by technology

The storage tube is installed in the car body beneath the rear window, in the roof or in the doors and therefore requires substantial installation expenditures.

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