EP3498964A1

EP3498964A1 - Operating mechanism for a window covering

Info

Publication number: EP3498964A1
Application number: EP18212361.2A
Authority: EP
Inventors: Nanne Willem Valkenburg
Original assignee: Vako BV
Current assignee: Vako BV
Priority date: 2017-12-13
Filing date: 2018-12-13
Publication date: 2019-06-19
Anticipated expiration: 2038-12-13
Also published as: DE202018105746U1; EP3498964B1; NL2020083B1

Abstract

The invention relates to an operating mechanism and in particular to a child-safe operating mechanism for a window covering, comprising a stationary carrying structure which can be fitted to the fixed surroundings, a drive axle, a contact body, a winding reel onto which at least a part of the window covering can be wound, a drive wheel wherein the drive wheel is releasably accommodated in the holding space, and at least one pressure element for forcing the contact body in the direction of an engagement wall of the carrying structure in the longitudinal direction of the drive axle.

Description

The invention relates to an operating mechanism, and in particular to a child-safe operating mechanism, for a window covering. The invention also relates to an assembly of a window covering and such an operating mechanism.
There are European regulations regarding the safety of window coverings in place in order to prevent injuries to people, and in particular children. The aim of these so-called child-safety regulations is, inter alia, to prevent children from suffocating as a result of becoming trapped in the loop of a cord or a chain. A known measure to meet these is the provision of a window covering in which the operating mechanism is provided with a drive wheel provided with a cord or chain which is removably accommodated in a housing of the operating mechanism. If excessive force is applied to the cord or the chain, and thus to the drive wheel, the cord or the chain will be removed from the housing, together with the drive wheel. By means of such a device, it is possible to prevent a child from becoming entangled with the cord and suffering serious injuries as a result.
It is an object of the invention to provide an improved operating mechanism for a relatively child-safe window covering.
To this end, the invention provides an operating mechanism for a window covering comprising a stationary carrying structure which can be fitted to the fixed surroundings, a drive axle which is preferably at least partly accommodated in the carrying structure, a contact body which is coupled to the drive axle so as to be movable in longitudinal direction of the drive axle, a winding reel which is driven by the drive axle and onto which at least a part of the window covering can be directly or indirectly wound, a drive wheel which is at least partly accommodated in a holding space enclosed between the contact body and an engagement wall of the carrying structure which is situated opposite the contact body, wherein the contact body and the engagement wall of the carrying structure engage with opposite sides of the drive wheel, and wherein the drive wheel is releasably accommodated in the holding space, and wherein the contact body is configured to be moved in a direction facing away from the engagement wall of the carrying structure in order to be able to remove the drive wheel from the holding space, at least one pressure element for forcing the contact body in the direction of the engagement wall of the carrying structure in the longitudinal direction of the drive axle, and at least one retention element for limiting the movement of the contact body in the direction of the engagement wall in such a way that, if the drive wheel is removed from the holding space, the contact body is and remains situated at a distance from the engagement wall of the carrying structure.
An advantage of the operating mechanism according to the invention is the fact that the operating mechanism is relatively user-friendly, because the contact body is permanently situated at a distance from the engagement wall of the carrying structure, even if the drive wheel is removed from the holding space. This permanent distance is achieved by the fact that the at least one retention element limits the movement of the contact body in the direction of the engagement wall. The distance which is therefore present between the contact body and the engagement wall during the absence of the drive wheel ensures that (re)placing the drive wheel in the holding space is significantly facilitated. In addition, the drive wheel will be stabilized after it has been placed in the holding space because the contact body, on account of the spring force of the pressure element, exerts a force (prestress) on the drive wheel and is forced in the direction of and up against the engagement wall of the carrying structure, as a result of which the drive wheel is de facto clamped in the holding space between the contact body and the engagement wall of the carrying structure. The tendency of the contact body to force objects in the direction of the drive wheel thus ensures a stable positioning of the drive wheel in the carrying structure. This is important because the mutual engagement of the contact body and the drive wheel ensures that, upon operation of the drive wheel, a rotating motion is transmitted to the contact body and to the drive axle via the contact body. The (spring) force which the pressure element exerts on the contact body thus has to be sufficiently large for the operating mechanism to be able to wind up and unwind a window covering in a relatively stable and reliable manner. However, this (spring) force also has to be sufficiently small to ensure timely removal of the drive wheel in case sufficient force is exerted in a downward direction, in order to ensure that the operating mechanism is child-safe. With regard to the latter, a balance will have to be found. An outer side of the engagement wall facing away from the holding space usually forms an outer side of the operating mechanism as such. An additional advantage of the operating mechanism according to the invention is the fact that the operating mechanism can be relatively compact, because the winding reel, the drive axle, and the contact body are linked in the position of use, in which case the window covering may - in addition to the winding reel - also at least partly, and even substantially completely surround (enclose) the drive axle and the contact body during winding-up of the window covering. In this embodiment of the operating mechanism according to the invention, a substantial part of the operating mechanism is thus situated in the window covering wound onto the winding reel, which is particularly advantageous from a practical, economic and aesthetic point of view. The winding reel is configured such that at least a part of the window covering may be wound thereon directly or indirectly.
While (re)placing the drive wheel in the carrying structure, the contact body which is movable in the longitudinal direction of the drive axle and coupled to the drive axle will move in a direction facing away from the engagement wall. Because the pressure element will continue to force the contact body in the direction of the engagement wall, the user will also be required to apply a force in order to replace the drive wheel. As has already been indicated, greatly reducing the force which the pressure element exerts is not desirable, because this may adversely affect the stabilization of the unit and the transmission of the rotation. By defining the minimum distance between the contact body and the engagement wall of the carrying structure by means of a retention element as referred to in the present invention, it will be possible to (re)place the drive wheel in the carrying structure without auxiliary means and/or great effort on the part of the user, and thus in a relatively user-friendly way.
In a possible embodiment of the operating mechanism, at least a front side of the contact body is configured for engagement with the drive wheel, in which case a rear side of the contact body facing away from the front side is engaged by at least one pressure element. The at least one pressure element may be at least partly accommodated in the contact body. In this case, the contact body will be designed to be at least partly hollow. The operating mechanism thus provides a relatively simple construction in which the contact body is able to force the drive wheel in the direction of the engagement wall of the carrying structure.
The at least one retention element is preferably configured to cooperate with at least one stop face for limiting the maximum movement of the contact body in the direction of the engagement wall of the carrying structure, the at least one stop face preferably defining at least a part of a recess, in particular a slot. The at least one retention element is for example configured to engage with the at least one stop face. In this case, it is conceivable that the at least one retention element is at least partly accommodated in the recess. It is also conceivable that the at least one retention element and the recess are movable with respect to each other between a position wherein the at least one retention element engages with the at least one stop face and a position wherein the retention element and the at least one stop face are situated at a distance from each other.
A variant embodiment is possible wherein at least one first retention element forms part of the drive axle, which at least one first retention element is preferably configured to cooperate with at least one first stop face which forms part of the contact body, wherein, more preferably, the at least one first stop face defines at least a part of a recess provided in the contact body. By means of this configuration, it is not only possible to limit the maximum movement of the contact body in the direction of the engagement wall of the carrying structure, but also the mutual movement between the contact body and the drive axle. This has the advantage that the contact body and the drive axle can already be mutually coupled, preferably in combination with the pressure element, and can be fitted in and/or on the carrying structure of the operating mechanism in a coupled state. In a further possible variant embodiment, the at least one first retention element is fitted at the head end of the drive axle, the at least one first retention element laterally projecting with respect to another part of the drive axle. In this case, the retention element forms a flange which extends over at least a part of a peripheral side of the drive axle.
It is also conceivable for at least one second retention element to form part of the contact body, which at least one second retention element is preferably configured to cooperate with at least one second stop face which forms part of the drive axle, more preferably the at least one second stop face defining at least a part of a recess provided in the drive axle. By means of this configuration, it is also possible to limit the mutual movement between the contact body and the drive axle.
Preferably, at least a part of at least one retention element is substantially resilient, in such a manner that at least a part of the aforementioned retention element is movable with respect to the longitudinal direction of the drive axle. This variant embodiment facilitates mutual coupling between the contact body and the drive axle.
In a possible variant embodiment, the operating mechanism comprises several, preferably spaced-apart, retention elements. Providing several, preferably spaced-apart, retention elements may result in an improved limitation of the movement of the contact body in the direction of the engagement wall. The operating mechanism may comprise, for example, two retention elements.
In a possible embodiment of the operating mechanism, the pressure element is clamped between the contact body and the drive axle. In particular, it is possible for the pressure element to be clamped between the contact body and a flange connected to the drive axle. Preferably, in this case, the diameter of the flange is substantially equal to or larger than the diameter of the contact body. The pressure element may be formed, for example, by a coil spring surrounding the drive axle. It is also possible for the coil spring to also surround a part of the contact body. Preferably, the diameter of the coil spring is smaller than or equal to the diameter of the contact body. More preferably, the diameter of the coil spring is smaller than or equal to the diameter of the contact body and/or smaller than or equal to the diameter of a flange connected to the drive axle. This results in an efficient spatial positioning of components. It is also advantageous if the outer diameter of the contact body substantially adjoins the inner diameter of a part of the stationary carrying structure.
In a possible embodiment, the winding reel is substantially hollow and the winding reel surrounds at least a part of the carrying structure. By means of such an embodiment, it is possible to provide a relatively compact embodiment of the window covering. In this case, the outer side of the winding reel may be profiled at least partly. Profiling may facilitate coupling of the winding reel to a window covering.
In a further variant embodiment, the winding reel is configured to cooperate with a winding tube which at least partly surrounds the winding reel, wherein the winding tube is configured such that at least a part of the window covering is wound onto it. To this end, the winding reel may be provided, for example, with a narrower diameter at the position where the winding tube surrounds the winding reel. In a possible variant embodiment, the outer diameter of the winding tube adjoins the outer diameter of the winding reel. In this case, the winding tube may not only surround the winding reel substantially completely, but also at least a part of the assembly of the drive axle and the contact body. In this case, it is even conceivable for the winding reel, the drive axle and the contact body to be accommodated substantially completely in the winding tube.
In a possible variant embodiment of the operating mechanism, in which the winding reel is substantially hollow and in which the winding reel surrounds at least a part of the carrying structure, the winding reel is coupled to the drive axle by way of at least one transmission. The transmission is configured to transmit the rotation of the drive axle onto the winding reel. Preferably, the at least one transmission has a reducing transmission ratio, so that the winding reel performs less than a complete revolution upon a complete revolution of the drive wheel. The delaying mechanical transmission thus results in a delay in the number of revolutions of the winding reel with respect to the drive wheel. In this way, it is possible to provide an operating mechanism which is relatively easy to operate for the user, also if relatively heavy window covering is being used.
In a possible embodiment, the transmission comprises an axially rotatable planet gear carrier which engages with the winding reel, and at least one axially rotatable planet wheel which is connected to the planet gear carrier, the at least one planet wheel engaging with both an external toothing of the drive axle and an internal toothing of the stationary carrying structure. The drive axle provided with external toothing functions as a sun wheel and the stationary carrying structure functions as a stationary satellite wheel in the planetary gearing. In the operational state, the at least one planet wheel will have a direction of rotation which is opposite to the direction of rotation of the drive axle. The planet gear carrier and the winding reel will rotate in the direction of rotation of the drive axle. As has already been indicated above, the speed of rotation of the planet gear carrier and the winding reel will be lower than the speed of rotation of the winding axle. It is possible for the planet gear carrier to engage with an inner side of the winding reel. An embodiment of the operating mechanism is possible in which at least a part of the planet gear carrier is at least partly surrounded by a stabilizing spring, wherein the stabilizing spring preferably makes contact with an outer side of the planet gear carrier.
In a possible variant embodiment, the planet gear carrier comprises several, and preferably 3 or 4, axially rotatable planet wheels which are connected to the planet gear carrier, each planet wheel engaging with both an external toothing of the drive axle and an internal toothing of the stationary carrying structure. By means of such a configuration, a stable and reliable transmission of rotation may be achieved in which the risk of the transmission acting up is minimized.
In a further variant embodiment, at least one stabilizing spring, in particular a coil spring, is accommodated in the winding reel, a first end of the stabilizing spring cooperating with an inner side of the winding reel and a second end of the stabilizing spring cooperating with, for example, a part of the planet gear carrier. It is also possible for the second end of the stabilizing spring to cooperate with a flange connected to the drive axle. In this case, the inner side of the winding reel may be provided with a protuberance and/or recess with which the first end of the stabilizing spring can engage. In a possible embodiment, a clamping connection is provided between the stabilizing spring and at least a part of a rotating component, such as for example a part of the drive axle and/or the planet gear carrier. The use of a stabilizing spring has the advantage that the friction which exists between the spring and the component with which it engages results in a braking action.
It is possible for the drive axle to be fastened by means of at least one bearing which is mounted in the carrying structure. In a possible variant embodiment, a bearing is provided on the drive axle on either side of the planet gear carrier. The use of at least one bearing will benefit the durability of the operating mechanism.
In an advantageous variant embodiment of the operating mechanism, the smallest distance between the engagement wall of the carrying structure and the contact body is sufficiently large to (easily) introduce the drive wheel. The smallest distance between the engagement wall and the carrying structure is preferably smaller than or equal to half the thickness of the engagement wheel. Such a configuration has a positive effect on the ease of use of the operating mechanism.
In a possible variant embodiment, at least a front side of the contact body is configured to engage with the drive wheel, with the front side of the contact body being profiled. It is conceivable for a side of the drive wheel facing the contact body also to be provided with a (counter) profiling. A profiling of the contact body ensures more grip between the drive wheel and the contact body during engagement which may result in improved transmission of the rotation of the drive wheel onto the contact body. Also, the profiling may have a positive effect on placing the drive wheel in the carrying structure. This improved positioning is in particular possible if at least a front side of the contact body is configured to engage with the drive wheel, and the front side of the contact body has a substantially conical shape (tapering shape). Preferably, the drive wheel is at least partly provided with a complementary design on at least a part of the front side of the contact body. The thickness of the drive wheel is preferably smaller than the distance between the engagement wall and a part of the conically designed part of the contact body when the drive wheel is removed from the carrying structure. This significantly facilitates fitting the drive wheel in the holding space.
A part of the conically designed part of the contact body preferably comprises a guiding surface. The guiding surface may improve arranging the drive wheel in the carrying structure, because the movement of the drive wheel to the desired position may be forced, as it were, by the combination of the conical design and the guiding surface.
In a possible variant embodiment of the operating mechanism, the engagement wall of the carrying structure is provided with a recess to accommodate a part of the drive wheel. Preferably, the drive wheel is at least partly provided with a complementary projection which may be accommodated in the recess. In this way, the stability of the drive wheel in the carrying structure may be increased. It is also conceivable for the engagement wall to be provided with a projection which may, at least partly, be accommodated in a recess facing the engagement wall and provided in the drive wheel.
Usually, the drive wheel cooperates with an engagement element, in particular a (pulling) cord or (pulling) chain, in order to allow the drive wheel to be rotated manually via the engagement element. To this end, a peripheral side of the drive wheel is usually provided with a, preferably profiled, guide track for guiding the cord or the chain.
The invention also relates to an assembly of a window covering and an operating mechanism according to the invention, as described above. The window covering may be any conventional type of window covering, such as for example a roller blind. Such an assembly has the same advantages that have already been mentioned above.
Preferred embodiments of the invention will be described in the following non-limiting clauses:

1. Operating mechanism for a window covering comprising:
- a stationary carrying structure which can be fitted to the fixed surroundings,
- a drive axle which is preferably at least partly accommodated in the carrying structure,
- a contact body which is coupled to the drive axle so as to be movable in longitudinal direction of the drive axle,
- a winding reel which is driven by the drive axle and onto which at least a part of the window covering can be wound,
- a drive wheel which is at least partly accommodated in a holding space enclosed between the contact body and an engagement wall of the carrying structure which is situated opposite the contact body, wherein the contact body and the engagement wall of the carrying structure engage with opposite sides of the drive wheel, and wherein the drive wheel is releasably accommodated in the holding space, and wherein the contact body is configured to be moved in a direction facing away from the engagement wall of the carrying structure in order to be able to remove the drive wheel from the holding space,
- at least one pressure element for forcing the contact body in the direction of the engagement wall of the carrying structure in the longitudinal direction of the drive axle, and
- at least one retention element for limiting the movement of the contact body in the direction of the engagement wall in such a way that, if the drive wheel is removed from the holding space, the contact body remains situated at a distance from the engagement wall of the carrying structure.
2. Operating mechanism according to clause 1, wherein at least a front side of the contact body is configured for engagement with the drive wheel, in which case a rear side of the contact body facing away from the front side is engaged by at least one pressure element.
3. Operating mechanism according to clause 1 or 2, wherein at least one retention element is configured to cooperate with at least one stop face for limiting the maximum movement of the contact body in the direction of the engagement wall of the carrying structure, the at least one stop face preferably defining at least a part of a recess, in particular a slot.
4. Operating mechanism according to any of the preceding clauses, wherein at least one first retention element forms part of the drive axle, which at least one first retention element is preferably configured to cooperate with at least one first stop face which forms part of the contact body, wherein, more preferably, the at least one first stop face defines at least a part of a recess provided in the contact body.
5. Operating mechanism according to clause 4, wherein the at least one first retention element is fitted at the head end of the drive axle, the at least one first retention element laterally projecting with respect to another part of the drive axle.
6. Operating mechanism according to any of the preceding clauses, wherein at least one second retention element forms part of the contact body, which at least one second retention element is preferably configured to cooperate with at least one second stop face which forms part of the drive axle, more preferably the at least one second stop face defining at least a part of a recess provided in the drive axle.
7. Operating mechanism according to any of the preceding clauses, wherein at least a part of at least one retention element is substantially resilient, in such a manner that at least a part of the aforementioned retention element is movable with respect to the longitudinal direction of the drive axle.
8. Operating mechanism according to one of the preceding clauses, wherein the operating mechanism comprises several spaced-apart retention elements.
9. Operating mechanism according to one of the preceding clauses, wherein the pressure element is clamped between the contact body and the drive axle, in particular between the contact body and a flange connected to the drive axle.
10. Operating mechanism according to one of the preceding clauses, wherein the pressure element is formed by a coil spring surrounding the drive axle.
11. Operating mechanism according to clause 10, wherein the diameter of the coil spring is smaller than or equal to the diameter of the contact body.
12. Operating mechanism according to one of the preceding clauses, wherein the winding reel is substantially hollow and the winding reel surrounds at least a part of the carrying structure.
13. Operating mechanism according to clause 12, wherein the outer side of the winding reel is at least partly profiled.
14. Operating mechanism according to one of the preceding clauses, wherein the winding reel is configured to cooperate with a winding tube which at least partly surrounds the winding reel, wherein the winding tube is configured such that at least a part of the window covering is wound onto it.
15. Operating mechanism according to one of clauses 12-14, wherein the winding reel is coupled to the drive axle by way of at least one transmission.
16. Operating mechanism according to clause 15, wherein the at least one transmission has a reducing transmission ratio, so that the winding reel performs less than a complete revolution upon a complete revolution of the drive wheel.
17. Operating mechanism according to clause 15 or 16, wherein the transmission comprises an axially rotatable planet gear carrier which engages with the winding reel, and at least one axially rotatable planet wheel which is connected to the planet gear carrier, the at least one planet wheel engaging with both an external toothing of the drive axle and an internal toothing of the stationary carrying structure.
18. Operating mechanism according to clause 17, wherein the planet gear carrier engages with an inner side of the winding reel.
19. Operating mechanism according to clause 17 or 18, wherein at least a part of the planet gear carrier is at least partly surrounded by a stabilizing spring, wherein the stabilizing spring preferably makes contact with an outer side of the planet gear carrier.
20. Operating mechanism according to one of clauses 17-19, wherein the planet gear carrier comprises several, and preferably 3 or 4, axially rotatable planet wheels which are connected to the planet gear carrier, each planet wheel engaging with both an external toothing of the drive axle and an internal toothing of the stationary carrying structure.
21. Operating mechanism according to one of clauses 12-20, wherein the winding reel is provided, on an inner side, with a protrusion which extends parallel to the sleeve surface of the winding reel, wherein the protrusion leaves a space with the sleeve surface in which a stabilizing spring is accommodated which makes contact with the protrusion.
22. Operating mechanism according to one of the preceding clauses, wherein the drive axle is fastened by means of at least one bearing mounted in the carrying structure.
23. Operating mechanism according to one of the preceding clauses, wherein the smallest distance between the engagement wall of the carrying structure and the contact body is sufficiently large to introduce the drive wheel.
24. Operating mechanism according to one of the preceding clauses, wherein at least a front side of the contact body is configured to engage with the drive wheel, and wherein the front side of the contact body is profiled.
25. Operating mechanism according to one of the preceding clauses, wherein at least a front side of the contact body is configured to engage with the drive wheel, and wherein the front side of the contact body has a substantially conical shape.
26. Operating mechanism according to clause 25, wherein the thickness of the drive wheel is smaller than the distance between the engagement wall and a part of the conically designed part of the contact body.
27. Operating mechanism according to clause 25 or 26, wherein a part of the conically designed part comprises a guiding surface.
28. Operating mechanism according to one of the preceding clauses, wherein the engagement wall of the carrying structure is provided with a recess to accommodate a part of the drive wheel.
29. Operating mechanism according to any of the preceding clauses, wherein the drive wheel is provided with an engagement element, in particular a cord or chain, for manually rotating the drive wheel.
30. Assembly of a window covering and an operating mechanism according to one of the preceding clauses.

The invention will be explained by means of non-limiting exemplary embodiments illustrated in the following figures, in which:

Fig. 1a shows a side view of an operating mechanism for a window covering according to the invention,
Fig. 1b shows a cross section of the operating mechanism as illustrated in Fig. 1a in a first position,
Fig. 1c shows a cross section of the operating mechanism as illustrated in Figs. 1a and 1b in a second position,
Fig. 2a shows a diagrammatic view of the operating mechanism as illustrated in Fig. 1a in the first position,
Fig. 2b shows a diagrammatic view of the operating mechanism as illustrated in Fig. 2a in an exploded configuration,
Fig. 2c shows a further diagrammatic view of the operating mechanism as illustrated in Fig. 2a in an exploded configuration, and
Fig. 2d shows a selection of parts as illustrated in Figs. 2b and 2c in a further exploded configuration.

Figs. 1a-c show an operating mechanism (1) for a window covering according to the invention. In this case, Fig. 1a shows a diagrammatic representation of a side view of the operating mechanism (1) in a first position. Fig. 1b shows a cross section of a side view of the operating mechanism (1) as illustrated in Fig. 1a. Fig. 1c shows a cross section of the operating mechanism (1) as illustrated in Figs. 1a and 1b in a second position.
Fig. 1a shows a diagrammatic representation of an operating mechanism (1) for a window covering (not shown). The operating mechanism (1) comprises a stationary carrying structure (2) which can be fitted to the fixed surroundings. The operating mechanism (1) comprises a drive wheel (3) for coupling with a drive axle. The drive wheel (3) is provided with an engagement element (4) for manually rotating the drive wheel (3). In the illustrated embodiment, the engagement element (4) is formed by a cord (4). The operating mechanism (1) furthermore comprises a rotatable winding reel (5) for a window covering to be wound onto. The drive axle and further components which are present are illustrated in detail in Figs. 1b and 1c.
Fig. 1b shows a cross section of the operating mechanism (1) as illustrated in Fig. 1a. The operating mechanism (1) comprises a stationary carrying structure (2) which can be fitted to the fixed surroundings, a drive axle (6) which is at least partly accommodated in the carrying structure (2), a contact body (7) which is coupled to a head end of the drive axle (6) and a winding reel (5) which is driven by the drive axle (6) and onto which the window covering (not shown) can be wound. The operating mechanism (1) furthermore comprises a drive wheel (3) which is releasably accommodated in a holding space (8) enclosed between the contact body (7) and the carrying structure (2). The contact body (7) is coupled to the drive axle (6) so as to be movable in the longitudinal direction of the drive axle by way of a pressure element (9) in order to force the contact body (7) in the direction of an engagement wall (11) of the carrying structure (2). In the illustrated variant embodiment, the pressure element (9) is formed by a coil spring (9) surrounding the drive axle (6). In this case, the diameter of the coil spring (9) is substantially equal to the diameter of the contact body (7). However, it is also conceivable for the coil spring (9) to have a diameter which is smaller than the diameter of the contact body (9). The coil spring (9) is clamped between the contact body (7) and the drive axle (6), in particular between the contact body (7) and a flange (23) connected to the drive axle (6). The flange (23) has a diameter which is substantially equal to an inner diameter of the stationary carrying structure (2). The operating mechanism (1) furthermore comprises two retention elements (10a, 10b) for limiting the movement of the contact body (7) in the direction of the engagement wall (11). The retention elements (10a, 10b) are also configured for limiting the mutual movement between the drive axle (6) and the contact body (7). It is an object of the retention elements (10a, 10b) to ensure that the contact body (7) leaves a space between the contact body (7) and the engagement wall (11) upon maximum travel in the direction of the engagement wall (11). This space is visible in Fig. 1c, in which the drive wheel (3) has been removed from the carrying structure (2). In this case, the contact body (7) is and remains situated at a distance from the engagement wall (11) of the carrying structure (2). In the illustrated embodiment, each retention element (10a, 10b) is configured to cooperate with at least one stop face (13a, 13b) for limiting the maximum movement of the contact body (7) in the direction of the engagement wall (11) of the carrying structure (2). In the illustrated embodiment, each stop face (13a, 13b) defines at least a part of a recess (25a, 25b). The sides of the drive wheel (3) and the contact body (7) facing each other have an at least partly complementary design. As a result thereof, the contact body (7) can adjoin the drive wheel (3) in a virtually dimensionally stable manner, which has a positive effect on the transmission of the rotating motion of the drive wheel (3) onto the contact body (7). In this case, the front side of the contact body (7) has a substantially conical design. The side of the drive wheel (3) which is configured to engage with the contact body (7) comprises a recess having a complementary conical design. The sides of the drive wheel (3) and the engagement wall (11) of the carrying structure (2) which face each other in a coupled position have an at least partly complementary design. In this case, the drive wheel (3) comprises a protuberance (14) which is configured to engage with a recess (15) in the engagement wall (11) of the carrying structure (2). This design is clearly illustrated, in particular, in Fig. 1c. Both the protuberance (14) and the recess (15) are of a substantially conical design. In the illustrated variant embodiment, the carrying structure (2) comprises two detachable parts which may facilitate fitting the carrying structure (2) and the operating mechanism (1) in its entirety. The drive axle (6) is fastened by means of a first bearing (12) mounted in the carrying structure (2). The operating mechanism (1) comprises a further bearing (16) which is positioned between the winding reel (5) and a rotatable part (26) coupled with the drive axle (6). In the illustrated embodiment, the drive axle (6) is at least partly hollow which results in a saving in material. It is also possible for the drive axle (6) to be of a segmented construction. The operating mechanism (1) furthermore comprises a stabilizing spring (17). The operating mechanism (1) as illustrated comprises a transmission (18) which has a reducing transmission ratio, so that the winding reel (5) performs less than a complete revolution upon a complete revolution of the drive wheel (3). The transmission (18) is illustrated in more detail in Figs. 2b-d.
Fig. 1c shows a cross section such as illustrated in Fig. 1b, in which the drive wheel (3) has been removed from the carrying structure (2). Fig. 1c shows that the contact body (7) is situated at a distance from the engagement wall (11) of the carrying structure (2) because of the limiting effect of the retention elements (10a, 10b). Because the contact body (7) is provided with two recesses (25a, 25b), the contact body (7) can already be moved in a longitudinal direction of the drive axle (6) in a direction facing away from the engagement wall (11). This ensures, inter alia, that replacing the drive wheel (3) and the cord (4) in a user-friendly way is facilitated.
Fig. 2a shows a diagrammatic view of the operating mechanism (1) according to the invention as illustrated in Figs. 1a-c. Figs. 2b and 2c both show a diagrammatic view of the operating mechanism (1) as illustrated in Fig. 2a, but in an exploded configuration. Figs. 2b and 2c show the exploded operating mechanism (1), each from a different point of view. Fig. 2d shows selected parts of the operating mechanism (1) as illustrated in the preceding figures, with the parts of the operating mechanism (1) being separated further. As has already been indicated, identical reference numerals refer to similar or corresponding parts.
Fig. 2a shows that the winding reel (5) is at least partly profiled. In addition, the winding reel (5) comprises a projecting flange which adjoins a part of the carrying structure (2).
The operating mechanism (1) as illustrated in Figs. 2b and 2c comprises a transmission (18) which has a reducing transmission ratio, so that the winding reel (5) performs less than a complete revolution upon a complete revolution of the drive wheel (3). The transmission (18) comprises an axially rotatable planet gear carrier (19) which engages with the winding reel (5) and comprises several axially rotatable planet wheels (20) which are connected to the planet gear carrier (19). Each planet wheel (20) is configured to engage with both an external toothing (21) of the drive axle (6) and an internal toothing (22) of the stationary carrying structure (2). A laterally projecting part of the planet gear carrier (19) is configured to engage with an inner side of the winding reel (5), in such a manner that the rotating motion of the drive axle (6) can be transmitted onto the winding reel (5) via the planet gear carrier (19). A part of the planet gear carrier (19) is partly surrounded by the stabilizing spring (17), the stabilizing spring (17) making contact with an outer side of the planet gear carrier (19) and an inner side of the winding reel (5). In the illustrated embodiment, the planet gear carrier (19) comprises four axially rotatable planet wheels (20) which are connected to the planet gear carrier (19). The winding reel (5) is provided, on an inner side, with a protrusion which extends parallel to the sleeve surface of the winding reel (5), wherein the protrusion leaves a space with the sleeve surface in which a stabilizing spring (17) is accommodated which makes contact with the protrusion. The figures show that a part of the conically designed part of the contact body (7) comprises a guiding surface (24) in order to guide the drive wheel (3) to the desired position when placing the drive wheel (3) in the carrying structure (2). In particular, the contact body (7) comprises several mutually cooperating guiding surfaces (24).
Fig. 2d shows a selection of parts of the operating mechanism (1) which were already illustrated in Figs. 2b and 2c in a further exploded position. The drive axle (6) comprises a retention element (10a) for cooperation with a stop face (13a) which forms part of the contact body (7). The stop face (13a) is defined by at least a part of a recess (25a) in the contact body (7). In this case, the retention element (10a) comprises a projecting cam (10a) which is at least partly flexible, thus facilitating coupling between the drive axle (6) and the contact body (7). The contact body (7) and the drive axle (6) are movable in the longitudinal direction of the drive axle (6) with respect to each other. A coil spring (9) which is clamped between a flange (23) connected to the drive axle (6) and the contact body (7) is configured to force the contact body (7) in the direction of an engagement wall (11) of the carrying structure (2). The diameter of the flange (23) is substantially equal to the outer diameter of the contact body (7). The coil spring (9) surrounds a part of the contact body (7). In the illustrated variant embodiment, the drive axle (6) is at least partly hexagonal.
It will be clear that the invention is not limited to the exemplary embodiments illustrated and described herein, but that countless variants are possible without departing from the scope of protection of the attached claims which will be obvious to those skilled in the art.

Claims

Operating mechanism for a window covering comprising:
- a stationary carrying structure which can be fitted to the fixed surroundings,

- a drive axle which is preferably at least partly accommodated in the carrying structure,

- a contact body which is coupled to the drive axle so as to be movable in longitudinal direction of the drive axle,

- a winding reel which is driven by the drive axle and onto which at least a part of the window covering can be wound,

- a drive wheel which is at least partly accommodated in a holding space enclosed between the contact body and an engagement wall of the carrying structure which is situated opposite the contact body, wherein the contact body and the engagement wall of the carrying structure engage with opposite sides of the drive wheel, and wherein the drive wheel is releasably accommodated in the holding space, and wherein the contact body is configured to be moved in a direction facing away from the engagement wall of the carrying structure in order to be able to remove the drive wheel from the holding space,

- at least one pressure element for forcing the contact body in the direction of the engagement wall of the carrying structure in the longitudinal direction of the drive axle, and

- at least one retention element for limiting the movement of the contact body in the direction of the engagement wall in such a way that, if the drive wheel is removed from the holding space, the contact body remains situated at a distance from the engagement wall of the carrying structure.
Operating mechanism according to Claim 1, wherein at least a front side of the contact body is configured for engagement with the drive wheel, in which case a rear side of the contact body facing away from the front side is engaged by at least one pressure element.
Operating mechanism according to Claim 1 or 2, wherein at least one retention element is configured to cooperate with at least one stop face for limiting the maximum movement of the contact body in the direction of the engagement wall of the carrying structure, the at least one stop face preferably defining at least a part of a recess, in particular a slot.
Operating mechanism according to any of the preceding claims, wherein at least one first retention element forms part of the drive axle, which at least one first retention element is preferably configured to cooperate with at least one first stop face which forms part of the contact body, wherein, more preferably, the at least one first stop face defines at least a part of a recess provided in the contact body.
Operating mechanism according to Claim 4, wherein the at least one first retention element is fitted at the head end of the drive axle, the at least one first retention element laterally projecting with respect to another part of the drive axle.
Operating mechanism according to any of the preceding claims, wherein at least one second retention element forms part of the contact body, which at least one second retention element is preferably configured to cooperate with at least one second stop face which forms part of the drive axle, more preferably the at least one second stop face defining at least a part of a recess provided in the drive axle.
Operating mechanism according to any of the preceding claims, wherein at least a part of at least one retention element is substantially resilient, in such a manner that at least a part of the aforementioned retention element is movable with respect to the longitudinal direction of the drive axle.
Operating mechanism according to one of the preceding claims, wherein the operating mechanism comprises several spaced-apart retention elements.
Operating mechanism according to one of the preceding claims, wherein the winding reel is configured to cooperate with a winding tube which at least partly surrounds the winding reel, wherein the winding tube is configured such that at least a part of the window covering is wound onto it.
Operating mechanism according to Claim 9, wherein the winding reel is coupled to the drive axle by way of at least one transmission.
Operating mechanism according to Claim 10, wherein the at least one transmission has a reducing transmission ratio, so that the winding reel performs less than a complete revolution upon a complete revolution of the drive wheel.
Operating mechanism according to one of Claims 9-11, wherein the winding reel is provided, on an inner side, with a protrusion which extends parallel to the sleeve surface of the winding reel, wherein the protrusion leaves a space with the sleeve surface in which a stabilizing spring is accommodated which makes contact with the protrusion.
Operating mechanism according to one of the preceding claims, wherein the drive axle is fastened by means of at least one bearing mounted in the carrying structure.
Operating mechanism according to one of the preceding claims, wherein the engagement wall of the carrying structure is provided with a recess to accommodate a part of the drive wheel.
Assembly of a window covering and an operating mechanism according to one of the preceding claims.