This application claims the benefit of priority under 35 U.S.C. §119 of German Patent Application DE 10 2006 023 789.7 filed May 16, 2006, and German Patent Application DE 20 2007 000 605.5 filed Jan. 10, 2007, the entire contents of each German Patent Application is incorporated herein by reference.
The present invention pertains to a drive unit for a vertical Venetian blind with a shared driving element for the displacing motion and the rotating motion of vertical slats, with a differential gear, whose first driving element is coupled to the shared driving element, whose first driven element is coupled to first drive means for the rotating motion of the vertical slats, and whose second driven element is coupled to second drive means for the displacing motion of the vertical slats.
In drive units of this type, both the displacing motion and the rotating motion of the vertical slats are driven by means of the shared driving element. In the meaning of this patent application differential gear is defined here such that a driving element with two driven elements is coupled using gears, so that either both driven elements or, with one driven element fixed, the other driven element are or is driven by means of the driving element. Moreover, by means of a differential gear of this type, it is possible, like in a differential, by fixing one driven element, to achieve a reversal of direction of the other driven element. In drive units of the above-mentioned type, a driving gear for the displacing of the vertical slats is driven, for example, by means of a planet gear as a differential gear. In this case, moreover, a spline shaft for the rotation of the slats is driven via an outer ring on the pinion cage of the planet gear. Since the necessary forces for the rotation of the slats are lower than for the displacing of the slats, when the driving element is actuated, first the necessary rotating motion of the vertical slats is carried out and then the displacing of the vertical slats. In particular, in case of an open vertical Venetian blind, at first the vertical slats are rotated into their closed orientation and then extended in this closed, rotated position for closing the vertical Venetian blind. To open the vertical Venetian blind, the shared driving element is actuated in the opposite direction. Here, the vertical slats again rotate at first into their opposite rotated position because of the lower force that is needed for this. When this opposite rotated position is reached, a stop limits a first rotation, such that the rotating motion and the related first driven element are blocked. With another actuation of the shared driving element, a displacement of the vertical slats takes place by means of the second driven element for the complete opening of the vertical Venetian blind. So that the vertical slats do not now get hooked up in their opposite rotated position with the opening of the vertical Venetian blind, this opposite rotated position is aligned in such a way that complete shading in this opposite rotated position is not possible. However, with different angles of incidence, it would be desirable for the vertical slats to be able to be closed completely in both directions of rotation. Up to now, however, this possibility requires either a separate driving element for the rotating motion or a gear with switching possibilities between rotating motion and displacing motion. A separate driving element for the rotating motion is uncomfortable, since in this case, for example, two ball chains have to be operated and, according to experience, the wrong ball chain is usually actuated. Thus, instead of performing a turning of the vertical slats, a displacing of the slats may be actuated in this case, which, in the closed rotated state, may lead to hooking up of the vertical slats. A switchable gear is in turn complicated and prone to difficulties. Moreover, the actuation of such a switchable gear is possible only with difficulty at unfavorable pulling angles.
The basic object of the present invention is thus to provide a drive unit for a vertical Venetian blind, with which displacing motion and rotating motion of the vertical slats can be driven by means of a shared driving element, whereby a complete closing of the vertical slats is made possible in both directions of rotation and, at the same time, a hooking up of the vertical slats by means of moving same in an unsuitable rotated position shall be prevented as much as possible.
The object is accomplished in that in a drive unit of the type mentioned above another differential gear is inserted between the first driven element and the first drive means for the rotating motion.
When the vertical slats are rotated into their position necessary for opening the vertical Venetian blind, a reversal of direction can be brought about by means of this other differential gear to the extent that the vertical slats are at first completely rotated in the opposite direction for closing and with further actuation of the shared driving element in the same direction of actuation by means of the other differential gear, the vertical slats are at first again slightly opened, before moving of the vertical slats for opening starts.
One variant of the present invention is characterized in that the other differential gear has another driving element, another first driven element and another second driven element, that the other driving element is coupled to the first driven element, and that the other first driven element is coupled to the first drive means for the rotating motion. In this way, the drive means for the rotating motion can be driven with the other differential gear in a simple and reliable manner. Thus, it is possible for limiting means to be assigned to the other second driving element for limiting the motion of the other second driving element. The limiting means may have, for example, a spiral at the other second driven element and a worm gear assigned to same, which together form a stop for limiting the motion of the other second driven element. Moreover, it is advantageous if the limiting means are embodied such that the rotation range of the vertical slats is limited to 180°. In this way, a complete closing of the vertical slats in both directions of rotation can be achieved by means of actuating the shared driving element.
Another variant of the present invention is characterized in that other limiting means are assigned to the other driving element, which limit the relative motion between the other driving element and the other second driven element. If the motion of the other second driven element is thus hindered in this case by means of the limiting means, it can be guaranteed by means of the other limiting means that the other driving element can still be moved a little bit against the other second driven element. For example, the other limiting means may have another stop each at the other driving element and at the other second driving element. It is then possible that the relative motion between the other driving element and the other second driven element is limited to one revolution by means of the other stops. This embodiment offers the possibility to use the other stops for two discrete stopping positions. In this mode of operation, it is possible that when the shared driving element is actuated, a rotating motion is carried out to the extent that the limiting means prevent another rotation of the vertical slats, whereby, at the same time, the other stops completely block the other differential gear in this position. With another actuation of the shared driving element, a displacing motion of the vertical slats for closing then starts by means of the differential gear. If the shared driving element now in the closed state is actuated in the opposite direction, then the vertical slats are at first rotated in their opposite, closed rotated position by means of the other differential gear, whereby the limiting means in this opposite, closed, rotated position limit another motion of the other second driven element. If the shared driving element is now further actuated in the same direction, then a reversal of direction of the other first driven element takes place because of the blocked other second driven element. By means of the other stops, because of the reversal of direction of the other first driven element, the vertical slats can again be opened to the extent that the other differential gear is blocked by means of the other stops after one revolution between the other driving element and the other second driven element and thus a displacing motion via the differential gear is initiated. The other driving element may be connected to the other second driven element, for example, in a spring-mounted manner. No rigid stopping action occurs in this case. Rather, already with a sufficiently large opening angle of the vertical slats, such that the spring force corresponds approximately to the force needed for displacing, a displacing of the vertical slats can be started. The other driving element may be connected to the other second driven element, for example, by means of an especially pretensioned leg spring.
However, such a spring-mounted connection of the other driving element to the other second driven element may also be considered to be a drawback. On the one hand, malfunction may occur in case of defective coordination of the spring rate or wear or contamination of the mechanism, in which a displacing of the vertical slats already starts, before the springs are already deflected and the vertical slots have thus been rotated into a displaced position. Another advantageous variant arises hereby in that the other driving element is detachably connected to the other second driven element by means of a snap-in coupling. In this case, a spring force does not have to be overcome, but rather it is sufficient to release the snap-in coupling. This can be accomplished, for example, by the snap-in coupling having a radially pretensioned spring section at the other first driven element, which can be released from a coupling position with a release element assigned to the other second driven element. This spring section acts here as a carrier and is pretensioned in its coupling position in such a way that a snap-in connection is reliably produced in the coupling position by means of the spring force, while this snap-in connection is released with the release element when the spring section is released. Furthermore, it is advantageous if the spring section in the coupling position actively meshes with a mount assigned to the other second driven element. By means of this active meshing, for example, a torque can be transmitted from the spring section onto the mount and thus onto the other second driven element. An advantageous embodiment of the release element arises in that a section connected at the spiral can be driven by means of the worm gear when the stop for actuating the release element is reached. In this case, when the stop is reached, the section is actuated in such a way, for example, pressed radially inwards against a spring force, that the spring section is released from the mount, so that the result is an uncoupled position.
Another embodiment of the present invention is characterized in that the first drive means for the rotating motion of the vertical slats have a spline shaft, which is connected to the other first driving element in a manner adapted to rotate in unison. By means of such a spline shaft, a rotating gear in the traveling carriage of the vertical slats can be actuated in the known manner. At the same time, this spline shaft offers the possibility of also being used as a bearing for, for example, a toothed wheel as the other driving element.
Another variant of the present invention is characterized in that the other differential gear is a differential gear. The differential gear here may be a spur planet gear or a bevel planet gear. By means of a differential gear of this type, a reversal of direction can be achieved by fixing the gear housing as the other second driven element.
In another variant of the present invention, the shared driving element actively meshes with a lengthwise extended, endless pulling element. The shared driving element here may be a chain wheel and the pulling element may be a ball chain. In this way, the chain wheel can be actuated as the shared driving element with the ball chain in a reliable and largely slip-free manner.
An advantageous embodiment of the present invention is characterized in that the differential gear is a planet gear, whose central wheel is connected to the shared driving element in a manner adapted to rotate in unison. Consequently, the result is an especially compact design. The planet gear may have an outer ring as the first driven element, which meshes with the other driving element. The outer ring may be arranged, for example, at a planet carrier. In this case, a good gearing can be achieved, so that at first a rotation of the vertical slats takes place when the shared driving element is actuated.
Moreover, it is possible for the second driven element to be actively connected to a driving gear for a pull cord, especially a ball chain, for displacing the vertical slats. If this pull cord is connected, for example, to the first carriage for the vertical slats, a reliable displacement with low exertion of force can thus be guaranteed in a simple manner and with little space requirement.
Another variant of the present invention pertains to a vertical Venetian blind with a drive unit having the features of the present invention. With such a vertical Venetian blind, shading can be brought about at any angles of incidence in a simple manner and without the risk of error on the part of the operator.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
In the drawings:
Referring to the drawings in particular,
As can be inferred from
The planet gear 13 has a first driven element 17 and a second driven element 16. The first driven element 17 in this embodiment is an outer ring 17 on the outer circumference of the planet gear 13, namely on the planet carrier, and the second driven element 16 is a bevel gear 16.
As can be further inferred from
Meshing with the spiral 22, a stop element 24 is pivotably arranged about an axle 23. The stop element 24 has a toothed ring section 25.
As can be further inferred from
The mode of operation of the drive unit 10 is explained in detail below on the basis of
If now the vertical slats shall be rotated out of the extended position for the complete closing in the opposite direction because of an unfavorable angle of incidence, then the chain wheel 15 is actuated in the opposite direction. The vertical slats are rotated here in the opposite direction by the sleeve 20 being rotated by means of actuating the toothed wheel 18 via the outer ring 17 by means of the spring force of the leg spring 19 to the extent that the stop element 24 has been rotated from the position shown in
For opening the vertical Venetian blind, the chain wheel 15 can be further actuated in the same direction. Because the spiral 22 stops at the stop element 24 and thus prevents a further rotation of the bushing 20, the bevel gear 28 can be rotated one revolution further against the bushing 20 while tensioning the leg spring 19 until the stop 36 comes to lie at the stop 35 as shown in
For better overall view,
The mode of operation of the drive unit 38 is explained in detail below on the basis of
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
Number | Date | Country | Kind |
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10 2006 023 789.7 | May 2006 | DE | national |
20 2007 000 605.5 | Jan 2007 | DE | national |