GB2578220A - Operating mechanism for a window covering - Google Patents

Abstract

An operating mechanism 30 comprising a stationary support structure 31, a rotatable winding spool and a drive wheel 2 connected rotatably and detachably in an area enclosed by the support structure. There is provided a canopy 3 connected to and independently rotatable relative to the drive wheel that at least partially encloses a chain 4. The canopy leaves a continuous gap (17, fig 1) clear for feeding the chain onto an engagement surface (5, fig 1) of the drive wheel. The gap has a maximum width larger or equal to the minimum diameter of the chain. The canopy may be elastically deformable to permit the gap width to adapt. The mechanism may be provided as part of a window, and a method is disclosed for installing the mechanism. The mechanism prevents injury to children by releasing from the support structure without detaching small components which pose a choking hazard.

Description

Operating Mechanism for a Window Covering The invention relates to an operating mechanism, and in particular a child-safe operating mechanism for a window covering. The invention also relates to an assembly of a drive wheel provided with an independently rotatable canopy connected to the drive wheel and an endless chain or an endless cord for use in an operating mechanism of this kind. In addition, the invention relates to a window covering comprising an operating mechanism of this kind. Lastly, the invention relates to a method for installing aforementioned assembly in a control mechanism of this kind.

For the prevention of injury to people, and in particular to children, there are regulations in respect of the safety of window covering. These so-called child-safety requirements are aimed, among other things, at preventing children from hanging themselves in a cord or chain loop. A known measure for complying with this is to provide a window covering in which the operating mechanism is provided with a drive wheel provided with a cord or chain which is removably incorporated in a housing of the operating mechanism. If an 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. A device of this kind makes hanging in the cord or chain loop effectively impossible.

However, the possibility of removing the drive wheel together with the cord or the chain from the operating mechanism leads to new safety risks. If the drive wheel and/or the cord or the chain only have small dimensions, these components, when coming away from the rest of the operating mechanism, may be put into their mouth and (partly) swallowed by children. As such, the detached components also present a choking hazard for children which needs to be taken into account. An aim of the invention is therefore to provide a child-safe operating mechanism for a window covering which enables mitigation of safety risks in respect of hanging as well as ingestion hazard.

To this end, the invention provides an operating mechanism for a window covering, comprising: a stationary support structure, a rotatable winding spool supported by the support structure, for winding by the window covering or a suspension cord connected to the window covering, a drive wheel, provided on the circumferential side of an engagement surface with which an endless chain or endless cord engages, the drive wheel being rotatably and detachably enclosed in a pick-up area by the support structure and the drive wheel being in contact with a transmission for transmitting a rotation onto the winding spool, a canopy independently rotatable relative to the drive wheel, connected to the drive wheel, which at least partially screens the engagement surface of the drive wheel for enclosing the chain or the cord between the engagement surface and the canopy, the canopy leaving a continuous gap clear, the gap in longitudinal direction connecting two ends of the canopy together which are located opposite each other in circumferential direction of the drive wheel, as well as forming a connection between a side of the canopy facing towards the engagement face and a side of the canopy facing away from the engagement surface across the entire length of a connection, the gap being arranged for feeding the chain or the cord in circumferential direction, the gap having a maximum width at every point that is larger than or equal to the minimum diameter of the chain or the cord.

In a customary case, the stationary support structure is arranged to be attached to the solid world, such as a wall or a ceiling. Hereby, the support structure supports the winding spool and as such indirectly the window covering suspended from it. To this end, the window covering can be wound directly around the winding spool, but can also be suspended from one or a plurality of suspension cords which in turn are wound around the winding spool. The winding spool is further in contact with the drive wheel by means of a transmission. This transmission enables transmitting a rotation from the drive wheel onto the winding spool, thus enabling lowering and raising of the window covering. The transmission often comprises a drive shaft by which the winding spool is driven. The transmission can also comprise a coupling body enabling a detachable coupling from the drive wheel onto the transmission. In a particular case, a coupling body of this kind is arranged to come away from the drive wheel, when the drive wheel is removed, so that the drive wheel is released and it can be moved out of the pick-up area enclosed by the support structure. With this moving away of the coupling body from the drive wheel, the coupling body often applies a counter-force in the direction of the drive wheel, so that the drive wheel is uncoupled from the coupling body and can be pulled out of the pick-up area only by application of a predetermined force. The drive wheel is rotated by the user by means of a loop-shaped chain or loop-shaped cord surrounding the drive wheel. Hereby, the chain or the cord engages with an engagement surface located to the circumferential side of the drive wheel, which, in a particular case, is provided with profiling so that the chain or the cord cannot slip away relative to the engagement surface. For the same reason, the chain or the cord can also be provided with a profiling which can then connect to the profiling of the engagement surface. In a possible embodiment, the chain can for example be formed by a ball chain, the balls of which grip onto a groove formed into the engagement surface in which recesses or hollows have been made.

Although, in the foregoing, reference is made to a winding spool, a drive shaft, a transmission and a drive wheel as if they were found in the singular in the operating mechanism, it is also highly conceivable that the above-mentioned and any components associated with them are embodied in the plural. As such, the window covering can be wound around a plurality of winding spools which are in connection with a single or a plurality of drive shafts. In the latter case, the drive shafts can be coupled together or separately and can be driven by intervention of one or a plurality of transmissions by a plurality of drive wheels.

The operating mechanism also comprises a canopy independently rotatable relative to the drive wheel and connected to the drive wheel, which screens the engagement surface at least partially off from the drive wheel, resulting in the chain or the cord being enclosed, essentially in secured manner, between the engagement surface and the canopy. As such, the chain or the cord cannot simply be released from the drive wheel. As the drive wheel is independently rotatable relative to the drive wheel, the canopy will not, or to a restricted extent, rotate along with the drive wheel so that the chain or the cord is not impeded by the canopy when it goes around the drive wheel. By means of the continuous gap left clear by the canopy, the maximum width of which is larger than or equal to the minimum diameter of the chain or the cord at each point, it is possible to position a loop-shaped and therefore endless chain or cord around the drive wheel without releasing the canopy of the drive wheel to do so. To this end, the gap forms a continuous connection between a side of the canopy facing towards the engagement face and a side of the canopy facing away from the engagement surface, the continuous connection also extending along the entire length of the canopy as seen from the circumferential direction of the drive wheel. Hereby, the gap connects the two ends of the canopy located opposite each other in circumferential direction of the drive wheel.

As the operating mechanism according to the invention is provided with a canopy so that a chain or cord located around the drive wheel is enclosed between the engagement surface and the canopy, this chain or cord will remain fixed to the drive wheel when the drive wheel is released from the pick-up area. Hereby, the assembly of the drive wheel with chain or cord coupled together is larger than the separate components, so that the risk of ingesting and the associated choking hazard is reduced compared with operating mechanisms for window coverings with removable drive wheels, the chain or cord of which is positioned loose around the drive wheel whereby the drive wheel and chain or cord can therefore be swallowed separately.

It is advantageous in case the gap at each point has a maximum width which is smaller than the maximum diameter of the chain or the cord. As such, a chain or the cord, the diameter of which varies across the length, can be fed through the gap in one or some particular orientations only, so that the chance that the chain or the cord can spontaneously escape the space between the canopy and the drive wheel is effectively minimised. It is advantageous in particular in case the gap at each point has a maximum width which in essence corresponds with the minimum diameter of the chain or the cord. A narrow gap of this kind reduces the chance that the chain or the cord can spontaneously escape the space between the canopy and the drive wheel to a further extent. In this case, it is essential for the chain or the cord to be fed through the gap across a part with a minimum diameter.

In a possible embodiment of the operating mechanism according to the invention, the canopy can be at least partially elastically deformable, the width of the gap being adaptable by elastic deformation of the canopy. By means of an at least partially elastically deformable canopy, it becomes possible to temporarily increase the width of the gap left clear by the canopy when feeding the chain or the cord through, the chain or the cord (easily) being able to be fed through the gap and being positioned around the drive wheel. Once the chain or the cord is positioned around the drive wheel, the width of the gap can be reduced or even be reduced fully to zero by the canopy returning to the non-deformed state. In the latter case, a deformation of the canopy or part thereof is therefore essential when installing the cord or the chain around the drive wheel, so that the chance that the chain or the cord can spontaneously escape the space between the canopy and the drive wheel is further reduced. In the case that the gap is left clear between the canopy and a part of the drive wheel, it is also possible that the drive wheel or part thereof is elastically deformable to achieve the adaptability of the width of the gap. In that case, both the drive wheel or a part thereof and the canopy or a part thereof can be elastically deformable.

In another possible embodiment of the operating mechanism according to the invention, the drive wheel can comprise two side walls positioned at the front sides of the drive wheel, the canopy being connected to at least one of the side walls. By attaching the canopy to at least one of the side walls located to both sides of the circumferential side, the circumferential side can be left entirely clear for engagement by the chain or the cord. However, it is also conceivable that the canopy is connected laterally to the engagement surface by the circumferential side of the drive wheel. On one side of the engagement surface, the canopy can be connected to the drive wheel to a side wall of the drive wheel or to the circumferential side of the drive wheel, the canopy not being connected to the side of the drive wheel that is located on the other side of the engagement surface. Hereby, the gap will be left clear between the canopy and a part of the drive wheel. It is also possible that the canopy is connected to both sides of the engagement surface with the drive surface, in which case, the gap is left clear by two opposite parts of the canopy.

The canopy can be connected to at least one of the side walls by means of engagement of the canopy onto a securing element fitted to a side wall. A securing element of this kind can be formed by a deepening or a protrusion, which engages with onto a protrusion or deepening respectively arranged on the canopy. The securing element can be formed in particular by a recess made into the side wall, the canopy comprising a mounting bracket for clamping the recess in a secured manner. Hereby, the assembly of recess and mounting bracket is preferably arranged such that the mounting bracket and the recess are not under pretension when the mounting bracket is engaging the recess. This ensures that mutual rotation of the canopy relative to the drive wheel can take place with as little friction as possible between the mounting bracket and the recess. Hereby, it is conceivable that the mounting bracket and/or the recess must be elastically deformed during installation so that attachment of the mounting bracket in the recess actually produces a clamping effect. In that case, removal of the mounting bracket from the recess would mean that a force must be applied to the mounting bracket and/or the recess, thus preventing the mounting bracket spontaneously releasing from the recess.

In another possible embodiment of the operating mechanism according to the invention, the front sides, and in particular the side walls of the drive wheel, are arranged to grip retention elements provided to sides of the pick-up area facing each other. To this end, the front sides can be provided with counter-elements enabling the retention elements of the pick-up area to be gripped. The retention elements serve in the first place to attach the drive wheel detachably to the pick-up area. To this end, the retention elements and counter-elements often have a complementary design chosen such that the retention elements and counter-elements shift relative to each other when a sufficiently large force is applied to the drive wheel so that the drive wheel is released from the pick-up area. To this end, retention elements and counter-elements can possibly comprise an in essence conical design. In addition, at least one of the retention elements is arranged as coupling body with which a detachable coupling of the drive wheel can be established on the transmission. Preferably, the coupling body closes in an in essence form-stable counter-element, in a position of the drive wheel attached in the pick-up area, at a front side of the drive wheel, so that a rotating motion of the drive wheel can be transmitted to the coupling body without slipping.

It is possible that at least one of the side walls of the drive wheel extends past the engagement surface in the radial direction for limiting the engagement surface in the axial direction. This can prevent the chain or the cord running off the drive wheel. In addition, this at least one extended side wall can work together with the canopy for enclosing the chain or the cord between the engagement surface of the drive wheel and the canopy. Hereby, it is also possible that the gap is enclosed between the side wall extending past the engagement surface in radial direction and the canopy.

In another possible embodiment of the operating mechanism according to the invention, the pick-up area can comprise two walls located opposite each other, said walls in a position of the drive wheel attached in the pick-up area facing towards the circumferential side of the drive wheel and functioning as stop surfaces for the ends of the canopy located opposite each other in the circumferential direction of the drive wheel for limiting the rotation of the canopy within the pick-up area. Hereby, the limiting of the rotation of the canopy therefore takes place because an end of the canopy which limits the canopy in the circumferential direction of the drive wheel, is positioned against a wall of the pick-up area facing towards the circumferential side of the drive wheel. Hereby, it is conceivable that the distance between the walls of the pick-up area located opposite each other is larger than the length of the canopy measured between the ends of the canopy located opposite each other in the circumferential direction of the drive wheel. As such, it may be possible for the canopy to rotate in the pick-up area to a restricted extent. However, it is also conceivable that the distance between the walls of the pick-up area located opposite each other correspond in essence with the length of the canopy measured between the ends of the canopy located opposite each other in the circumferential direction of the drive wheel. In this case, it is not possible for the canopy to rotate relative to the pick-up area if the drive wheel is attached in the pick-up area. An advantage of not being able to rotate the canopy, or only to a restricted extent, relative to the pick-up area is that the canopy is prevented from rotating along with the drive wheel so that the canopy does not come into contact with the chain or the cord. Another advantage of the fact that the walls of the pick-up area limit the space for the canopy to move is that the drive wheel with canopy is led along the walls of the pick-up area when pulling the drive wheel out of the pick-up area, the drive wheel therefore being sent in direction of motion. This ensures a controlled removal of the drive wheel from the pick-up area.

The operating mechanism can further comprise at least one screening element connected to the canopy for at least partially screening part of the drive wheel facing toward an opening in the support structure in a position attached to the pickup area of the drive wheel. In a particular case, this screening element is located at a circumferential side of the drive wheel, opposite the canopy. Because the screening element, generally formed by a hood or wall part, is connected to the canopy, if the rotation of the canopy within the pick-up area is limited, the rotation of the screening element is limited too. This makes it possible to prevent the screening element from obstructing the run-out of the chain or the cord from the opening in the pick-up area. However, it is also conceivable that the rotation of the screening element within the pick-up area is limited because the walls of the pick-up area function as stop surface for the screening element. By connecting the screening element to the canopy, the rotation of the canopy within the pick-up area will be limited too. By screening off the drive wheel at least partially so that it is not accessible, or to a limited extent only, from an opening in the support structure, objects or body pads can be prevented from coming into contact with the drive wheel and hence with the rotating mechanism of the operating mechanism. This can prevent damage to aforementioned objects or body parts as well as damage to the operating mechanism. An additional advantage of screening one part of the drive wheel facing toward an opening in the support structure is that, as such, the opening in the pick-up area is generally screened off too, which can be desirable from an aesthetic perspective.

The invention also relates to an assembly of a drive wheel provided with an independently rotatable canopy connected to the drive wheel and an endless chain or an endless cord for use in an operating mechanism according to the invention.

The canopy screens off the engagement surface of the drive wheel, thus at least partially enclosing the chain or the cord between the engagement surface and the canopy. Further, the canopy leaves a continuous gap clear, the gap in longitudinal direction connecting two ends of the canopy together located opposite each other in circumferential direction of the drive wheel as well as forming a connection across the entire length between a side of the canopy facing towards the engagement surface of the canopy and a side facing away from the engagement surface of the canopy, the gap being arranged for feeding the chain or the cord in circumferential direction, the gap having a maximum width at every point which is larger than or equal to the minimum diameter of the chain or the cord. The advantages of an assembly of this kind have already been extensively discussed in conjunction with the operating mechanism according to the invention.

In addition, the invention relates to a window covering comprising an operating mechanism according to the invention. A window covering of this kind encounters the same advantages as already described above in the context of the operating mechanism. As mentioned above, the window covering can be wound directly around the at least one winding spool of the operating mechanism. It is also possible that the window covering is suspended from one or a plurality of suspension cords which in turn are wound around the at least one winding spool.

The window covering itself can be any conventional type of window covering, such as a roller blind, a folding blind, a pleated blind, etc. Lastly, the invention relates to a method for installing an assembly of a drive wheel provided with an independently rotatable canopy connected to the drive wheel, and a chain or a cord in an operating mechanism according to the invention, comprising the steps of: A) feeding the endless chain or the endless cord through the gap in circumferential direction of the drive wheel so that the chain or the cord is enclosed between the engagement surface and the canopy, B) inserting the assembly of drive wheel and canopy in the pick-up area with the canopy first via an opening in the support structure, and C) having the retention elements provided to the sides of the pick-up area located opposite each other gripped by the side walls of the drive wheel and as such securing the chain wheel in the pick-up area. By means of this method of installation it becomes possible to position a loop-shaped chain or loop-shaped cord around a drive wheel in a simple manner, the chain or the cord, after installation around the drive wheel being enclosed between engagement surface and the canopy thus preventing that the chain or the cord is simply removed from the drive wheel. After installation of the chain or the cord, the drive wheel can be detachably fixed to the pick-up area using chain or cord. Hereby, the coupling of the drive wheel in the pick-up area is arranged such that the drive wheel is released from the pick-up area when a force above a predetermined value is applied to the chain or the cord, making hanging in the chain or the cord impossible. Furthermore, the chain or the cord remains connected to the drive wheel after the drive wheel has come away from the pick-up area, so that the dimensions of the released component are effectively enlarged so that the chance of ingesting it are effectively reduced.

The invention will now be clarified using non-limitative embodiment examples presented in the following figures. In the figures, corresponding elements are indicated by corresponding reference numbers. In the figures: Figure 1 shows a perspective view of an assembly of a drive wheel provided with a canopy and an endless chain for use in an operating mechanism according to the invention, Figure 2 shows another perspective view of the assembly of Figure 1, where the canopy is presented transparently, and Figure 3 shows a perspective view of an operating mechanism for a window covering according to the invention, provided with the assembly as shown in Figures 1 and 2.

Figures 1 and 2 show two perspective views of an assembly 1 of a drive wheel 2 provided with a canopy 3 and an endless chain 4 for use in an operating mechanism according to the invention. In Figure 2, canopy 3 is presented transparently to make the underlying elements of assembly 1 visible. Assembly 1 comprises a drive wheel 2 with an endless ball chain 4 positioned around it. Hereby, ball chain 4, using balls 22, engages with engagement surface 5 of drive wheel 2 which is provided to a circumferential side 6 of drive wheel 2 and in which recesses 7 have been made to prevent slipping of ball chain 4 relative to engagement surface 5. At front sides 8 of drive wheel 2, there are two side walls 9, which each are provided with counter-elements 11 for engaging a retention element as is provided in a pick-up area of an operating mechanism according to the invention. In the case shown, counter-elements 11 are formed by protrusion 12 and recess 13 respectively, both provided with a conical design. Counter element 11 formed as recess 13 is moreover provided with a profiling in the form of ribs 14 so that the retention element formed complementing it can connect to it so that a rotating motion of drive wheel 2 can be transmitted to aforementioned retention element without slipping. One of side walls 9 extends past engagement surface 5 in radial direction, engagement surface 5 of drive wheel 2 being limited in axial direction and as such preventing that ball chain 4 can run off drive wheel 2 in the same axial direction. Drive wheel 2 is further provided with an independently rotatable canopy 3 connected to drive wheel 2 which partially screens engagement surface 5 of drive wheel 2 and as such closes in ball chain 4 between engagement surface 5 and canopy 3. Canopy 3 is connected to a side wall 10 of drive wheel 2.

To this end, canopy 3 comprises a mounting bracket 15 which clamps a recess 16 fitted to aforementioned side wall 10 in a secure manner. In the position of canopy 3 shown, canopy 3 also limits engagement surface 5 of drive wheel 2 in axial direction, so that ball chain 4 is held back, on the one hand, in the axial direction by canopy 3 and, on the other hand, is held back in radial direction by side wall 9 extending past the engagement surface. Between side wall 9 extending past the engagement surface in radial direction and canopy 3, a gap 17 is enclosed where ball chain 4 can be fed through in circumferential direction. As such, canopy 3 does not need to be removed from drive wheel 2 when installing ball chain 4 around drive wheel 2. In order to enable this functionality, gap 17 in longitudinal direction connects two ends 18 of canopy 3 together, located opposite each other in circumferential direction of the drive wheel 2. Gap 17 also forms a connection across the entire length between a side 19 of canopy 3 facing towards engagement surface 5 and side 20 of canopy 3 facing away from engagement surface 5. Furthermore, gap 17 has a maximum width at every point which in essence corresponds with the minimum diameter of ball chain 4 at the level of elements 21 which connect balls 22 of ball chain 4 together.

Figure 3 shows a perspective view of an operating mechanism 30 for a window covering according to the invention, provided with assembly 1 as shown in Figures 1 and 2. This time, it has been chosen to present a part of support structure 31 of operating mechanism 30 transparently to make underlying elements of operating mechanism 30 visible. Operating mechanism 30 comprises a stationary support structure 31 which closes in a pick-up area 32 for drive wheel 2 in which drive wheel 2 is rotatably and detachably connected. Operating mechanism 30 also comprises a rotatable winding spool for winding by the window covering or a suspension cord connected to the window covering, this winding spool not being presented in this figure. In a particular case, support structure 31 is surrounded by the winding spool and the winding spool is supported by support structure 31. To this end, in a customary case, the winding spool also engages with drive shaft 33 supported by the support structure. This drive shaft 33 is part of a transmission with which a rotation is transmitted from drive wheel 2 onto the winding spool. Bordering onto drive wheel 2, the transmission is provided with a coupling body 34 which is detachably coupled with drive wheel 2. Except that this coupling body 34 transmits a rotation from drive wheel 2 via drive shaft 33 to the winding spool, this coupling body 34 also functions as retention element with which drive wheel 2 is detachably attached in pick-up area 32. Pick-up area 32 enclosed by stationary support structure 31 comprises two walls 35, 36 located opposite each other which are facing towards the circumferential side of drive wheel 2 attached to pick-up area 32. These walls 35, 36 function as stop surfaces for ends 18 of canopy 3 located opposite each other in circumferential direction of drive wheel 2 for limiting the rotation of canopy 3 within pick-up area 32. Pick-up area 32 further comprises a wall 37 which, in a position attached in pick-up area 32 of drive wheel 2, borders onto a front side of drive wheel 2. This wall 37 is provided with a retention element (not visible in figure 3) which engages with a counter element 12 fitted in a side wall 9 of drive wheel 2. Drive wheel 2 is therefore suspended between the retention elements fitted to the sides of pick-up area 32 located opposite each other, one of which is formed by coupling body 34 and the other of which is formed by retention element provided at wall 37.

It should be clear that the invention is not limited to the embodiment examples presented and described here, but that, in the framework of the accompanying claims, numerous variants are possible which will be obvious for the person skilled in the art. Hereby, it is conceivable that various inventive concepts and/or technical measures of the embodiment variants described above can be fully or partially combined without moving away from the inventive concept described in the attached claims.

The verb 'comprise' and conjugations thereof used in this patent specification mean not only 'comprise' but also the expressions 'contain', 'in essence exist', 'formed by', and conjugations thereof.