Title: Multiple curtain track system.

The present invention relates to a multiple curtain track system comprising a plurality of side-by-side positioned curtain tracks having a carrier guidance for guiding at least one curtain carrier.

US6.892.783 discloses such a multiple curtain track system for a panel curtain assembly. The disclosed panel curtain assembly comprises a plurality of panel curtains which hang in parallel to each other from the multiple curtain track system. The panel curtain assembly may be mounted in front of a window. The window may be covered by the panel curtain assembly by moving the panel curtains along the multiple curtain track system from an open position wherein the panel curtains hang side by side each other to a closed position wherein the panel-curtains hang in line with each other. As shown in a cross- sectional view in Fig. 11 of US6.892.783, the multiple curtain-track system comprises a track support having three carrier tracks positioned within it. A second carrier track is nested between a first and third carrier track. From each carrier track a panel curtain is suspended. Curtain carriers can move within the track support to move the connected panel-curtains from an open position to a closed position and vice versa.

A drawback of this disclosed multiple curtain track system is that it is hardly not usable for a curved arrangement of the panel curtains. The multiple curtain track system is designed to be used in a straight arrangement of the panel curtains. However, it is often desirable to mount the curtain assembly along a wall with some curvatures, e.g. along the windows in a bay. In a further frequent occurring arrangement, the curtain assembly has to be mounted in front of a window which is positioned close to a corner of a room. A corner beside a window may obstruct the panel curtains to be arranged at both sides of the window. If no concessions are allowed to the sight through the window, the panel curtains can only be arranged at one side of the window. If the window is positioned between two corners, there is even no other option than hanging the panel curtains in front of the window, wherein a part of the window remain covered when the panel curtains are in an open position. It is an object of the present invention to overcome at least one of the abovementioned drawbacks, at least partially, and/or to provide a usable alternative. In particular, it is an object of the invention to provide a multiple curtain track system which allows a curved arrangement of the panel curtains.

This object is achieved by a multiple curtain track system, as defined in claim 1. The multiple curtain track system according to the invention comprises a plurality of side-by-side positioned curtain tracks. Each curtain track comprise at least one carrier guidance. The curtain tracks comprise a carrier guidance for guiding at least one curtain carrier. The multiple curtain track system according to the invention is characterized in that two adjacent curtain tracks are provided with a pair of complementary connector organs for a slidable connection of the adjacent curtain tracks relative to each other. At least one of the curtain tracks comprises a side wall which is provided with a connector organ. The connector organ may be integral with the curtain track. Preferably each curtain track comprises two opposite side walls, wherein the side walls of two adjacent curtain tracks are provided with a pair of complementary connector organs for a slidable connection of the adjacent curtain tracks relative to each other. After connecting the curtain tracks to each other, the curtain tracks are movable along each other in a longitudinal direction of the curtain tracks. The slidable connection of the curtain tracks enable a bending operation on the multiple track system. During bending the curtain tracks slide along each other. This prevents the track system from non admissible high shear stresses during the bending operation and therefore reduces the risk on non admissible deformations or damages during bending. The slidable connection between adjacent curtain tracks further prevent the curtain tracks from deviating from each other. Advantageously, the curtain tracks remain close to each other during and after bending.

In addition, the slidable connection between the curtain tracks allow a further bending in comparison with non slidably connected curtain tracks. As a result the track system may be bend in more acute angles over a small radius. For instance, a track system having at least three curtain tracks, preferably at least five curtain tracks may be bent into an angle of e.g. from 180° to at least 210° over a radius of 10cm or to 225° over a radius of at least 15cm, wherein the radius is determined by the radius measured from the outside wall of an inner positioned curtain track. Preferably, the track system may be bent into an angle of at least 270° over a radius of at least 15cm. Herewith, the track system may also be used for curved curtain arrangements along e.g. bays or staggered walls. Advantageously, the track system may also be arranged in corners. The track system may be bend in a radius to overcome an angle of e.g. 90° between a wall and a window. The track system may be bend more than once to obtain a S-curve arrangement. Preferably, the track system is used for a panel curtain assembly. The panel curtain assembly may be used to cover a window in the corner, wherein it may be advantageously to arrange the panel curtains in an open position along the wall standing perpendicular to the window.

In a particular embodiment the track system according to the invention comprises at least two curtain tracks. Preferably the track system comprises at least five curtain tracks, because in many occasions five curtain tracks for five panel curtains satisfy given requirements. In an embodiment of the track system according to the invention, the pair of connector organs provide a snap-on fitting between the two adjacent curtain tracks. The snap on fitting of the curtain tracks allows an easy mounting of the curtain tracks to each other to form the multiple curtain track system. Preferably, the pair of connector organs comprise two complementary longitudinally connector organs. The connector organs extend at least partially along the length of the curtain track. Preferably, the connector organ extends along substantially the whole length of the curtain track. Herewith, the curtain tracks may be produced cost effective by an extrusion process. In an embodiment of the track system according to the invention, the pair of connector organs comprise a first connector organ having a longitudinal rill which extends at least partially along the side wall. The pair of connector organs may comprise further a second connector organ having a longitudinal groove which extends at least partially along the side wall. The rill of the first connector organ which is provided at a first connector organ may be fitted into the groove of a second curtain track. By inserting the rill under a predefined angle into the groove and subsequently pressing the first curtain track against the second curtain track, it may be very easy to connect the curtain tracks to each other.

In an embodiment of the track system according to the invention the track system comprises at least one substantially straight and at least one curved track system portion, wherein the curved portion is arranged according to claim 1 and wherein the substantially straight portion is formed by one integral track system portion. The integral track system portion may be formed without a slidable connection between the curtain tracks, because a bending of the curtain track portion is not necessary. The integral track system portion may be out of one piece. The integral track system portion may be manufactured by an extrusion process. The integral system portion may have a constant cross section over the whole length. The substantially straight portion can be aligned to the curved portion to obtain a complete track system. A heading of the straight portion may be connected to a heading of a curved portion, wherein a curtain carrier can be driven from a carrier guidance of a straight portion to a corresponding carrier guidance of a curved portion. In a further particular embodiment the track system according to the invention may be arranged with several track system portions, wherein the amount of carrier guidances differs for at least one track system portion. The total multiple track system may have at least two connectable track sytem portions wherein the amount of carrier guidances is not equal for all track system portions. For instance in a multiple track system a substantially straight track system portion comprises three carrier guidances, wherein an aligned and connected curved track system portion comprises five carrier guidances. Herewith, five panel curtains may be arranged along a curvature, wherein three panel curtains can be driven further along the straight portion. In another example, the straight portion may have six carrier guidances, wherein the curved portion has three carrier guidances. Herewith, it is possible to limit the total width of the curved track system portion, which may improve the allowable bending radius. In an embodiment of the track system according to the invention, the track system comprises a curtain carrier having a flexible panel strip. The flexible panel strip allows the curtain carrier to move through any curvatures in the curtain track. The flexible panel strip may be made of a fabric like cotton. Advantageously, the flexible panel strip may extend into the curtain track. This allows an arrangement of curtains without a chink between the curtain track and the curtain, which reduces the amount of light shining through the curtain assembly.

Preferably, the panel strip is made out of a Velcro strip. The curtain may be provided with a complementary piece of Velcro material. Advantageously, herewith it is easy to adjust the curtain during mounting. If the panel appears to be hanging just a little bit oblique, the curtain may easily be released and mounted again in a right manner.

In a further embodiment the panel strip may be provided with a sleeve in a hem. The sleeve may function as a gliding element and may be put into the carrier guidance of the curtain track. The sleeve in the hem may be of an elastic material, like rubber or silicon to provide sufficient flexibility to be guided through a curved curtain track. In a preferred embodiment the panel strip is provided with a plurality of track runners as gliding elements for guiding the curtain carrier through the carrier guidance. In stead of a sleeve-shaped track runner, the plurality of track runners provided lesser resistance when moving through a curved curtain track. The track runners may be out of plastic.

Advantageously, the plastic track runners generate little friction which provides good gliding properties. The track runners may all be separately connected to the panel strip. In an embodiment, the track runners may be integral with the curtain carrier. The track runners may be moulded to the curtain carrier which enables a cost effective production of the multiple track system. In another advantageous embodiment according to the invention the track runners are connected by a snap on fitting to the flexible panel strip. Herewith, the panel strip may be easily released from the curtain rail without demounting components at the ends of the curtain track. The panel strip may be provided with a plastic molded edge portion or band to get a more reliable fitting of the track runners to the panel strip. By providing components with snap on fittings, the panel strip of the curtain carrier can be produced in large lengths. A plurality of panel strips can be made by dividing a long strip into the desired dimensions. It may be cost effective to start the manufacturing of the curtain carrier with a long strip of e.g. about 50 meters. The long strip may consist of a Velcro part provided with a molde plastic edge. In an embodiment according to the invention, the gliding element may be resilient, such that the gliding element can be elastically deformed to put it into the carrier guidance of the curtain track without demounting at least a part of the track system. The resilient gliding element may be brought into the carrier guidance through the opening at the bottom region of the curtain track instead of through one of the openings at the ends of the curtain track as in conventional applications.

In an alternative embodiment the gliding element may comprise rollers. In particular for heavy loaded curtain systems, the rollers may provide a smooth running of the curtains. In a particular embodiment of the track system according to the invention the curtain track further comprises a drive-channel for guiding a drive element. The drive element may be a belt, tape, line etc. The drive element may be connected to curtain carriers and may be manually or automatically operated to open or close the curtains. Preferably, the drive element comprises a cord having at least one voluminous element for engaging the curtain carrier. The voluminous element may be ball, disk or tun shaped. Preferably, a plurality of voluminous elements are equally spaced over at least a part of the cord. The equally spaced voluminous elements allows advantageously a motorized operation of the multiple curtain track system. The motorized curtain track system may be controlled by time or light sensors to get an intelligent system which anticipates on different circumstances. Advantageously, the cord is hardly susceptible to elongation which allows a proper functioning of the track system during its lifetime. The voluminous element may be molded to the cord.

Advantageously, this embodiment of the drive element may have the flexibility to follow any curvatures of the curtain track and may provide good gliding properties. In addition the drive element may be strong enough to withstand occurring forces during the operation of the track system. In an embodiment of the track system according to the invention, the curtain carrier is provided with at least one drive engagement member for an engagement of the curtain carrier to the drive-element. Preferably, the drive engagement member is partly spherical to be complementary to the ball-element of the drive element. At the opposite part of the spherical part the engagement member may have a clamping part for clamping the engagement member to a curtain carrier. The clamping part may be snapped on the curtain carrier. In an alternative embodiment according to the invention the drive engagement member may be molded to the curtain carrier.

In a preferred embodiment according to the invention the multiple curtain track system further comprises a catch element. The catch element may be mounted to a curtain carrier. It may comprise a projecting part which is positioned substantially perpendicular to a mounting body, wherein the mounting body comprises a snap on fitting for mounting the catch element to a curtain carrier. The catch element may be released or placed by tilting the catch element in a transitional direction of a curtain carrier. Advantageously, herewith the catch element may be manually and easily released from a fully installed multiple curtain track system.

In an embodiment according to the invention of a catch element the projecting part is releasable coupled to the mounting body, wherein at least two fit positions are provided for coupling the projecting part to the mounting body. Preferably, the projecting part is manually releasable. Advantageously, the projecting part may be released from a fully installed multiple curtain track system. The mounting body of the catch element may be mounted to the curtain carrier by a snap on fitting and may be formed as a base block for inserting the projecting part. By providing an engagement of the mounting body to at least one gliding element, e.g. by providing protrusions on the mounting body, the mounting body may be positioned with respect to the gliding element of the curtain carrier. Herewith, the gliding elements which are preferably curtain runners define precisely the position of the mounting body. Preferably, the projecting part is manually connectable by a snap on fitting into the mounting body. The projecting part is subsequently connectable to the mounting body in at least two positions. This provides a user of the multiple curtain track system the opportunity to adjust the position of the projecting part relative to the other components of the curtain carrier and hence the overlapping distance of two parallel curtains. Herewith, advantageously a fine tuning of the multiple curtain track system may be possible after installing the multiple curtain track system.

Further preferred embodiments are defined in the subclaims.

The invention further relates to a method for bending a multiple curtain track system in accordance with claim 16. The method comprises the steps of: forming a set of curtain tracks by coupling a plurality of curtain tracks side by side to each other while leaving a degree of freedom to the curtain tracks to slide relative to each other; positioning the set of curtain tracks in a bending tool; and bending the set of curtain tracks all together. The curtain tracks may be coupled by connector organs at a side wall of at least one of the curtain tracks, but may also be coupled by a clip or an enclosure of a bending tool. The method is characterized in that during bending the curtain tracks move in a longitudinal direction relative to each other. The enclosure of the bending tool or the connector organ permits a movement of the curtain tracks in a length direction, while it keeps the curtain tracks close to each other. During the bending operation, the curtain tracks remain over substantially the whole length in contact to each other. Herewith, the permitted relative movement in length direction reduces the risks on damages caused by high shear stresses during bending may be reduced, while the resulting close fit of the curtain tracks may reduce the amount of light shining through the curtains.

In an embodiment of the method according to the invention a filler may be used during the bending operation. The filler may be positioned in a hollow space of the curtain track, e.g. the carrier guidance. Advantageously, the filler may prevent a collapsing of a curtain track.

Further preferred embodiments are defined in the further subclaims.

The invention will be explained in more detail with reference to the attached drawings which show a practical embodiment of the invention, but which should not be seen as being limiting. In these drawings:

Fig. 1A shows an exploded schematic view of a multiple curtain track system according to the invention including a detail view A which shows a motor arrangement as an alternative for a manual drive;

Fig. 1 B shows a detailed view of a closure according to the invention;

Fig. 1C shows a detailed view of an engagement member which is connectable to a curtain carrier;

Fig. 1 D shows a detailed view of an assembly of two pieces forming a catch element; Fig. 1 E shows a detailed view of a first piece of the catch element out of fig. 1 D;

Fig. 1 F shows a detailed view of a second piece of the catch element out of fig. 1 D;

Fig. 1G shows a detailed view of a T-shaped catch element in a closed configuration;

Fig. 1 H shows a detailed view of a T-shaped catch element in an open configuration;

Fig. 2 shows in a view a bent multiple curtain track system according to the invention including curtain tracks and bendable curtain carriers;

Fig. 3a-e show cross sectional views of a curtain track comprising a particular arrangement of a connector organ;

Fig. 4a-c show in a cross sectional view a preferred embodiment of a curtain track according to the invention; Fig. 5 show in a cross sectional view an alternative embodiment of an assembly of a multiple panel curtain track system according to the invention.

In the appended drawings equal reference numbers are used for corresponding components. Fig. 1A shows in an exploded view a multiple track system which is arranged as a panel curtain assembly. The track system may be mounted to a ceiling or window post for the suspension of curtains. The track system comprises side by side positioned curtain tracks 10. The curtain tracks 10 are positioned against each other. Each curtain track is provided with a carrier guidance. The carrier guidance is formed by an opening at the underside of the curtain track. The opening is longitudinally extending over the whole length of the curtain track. Along a side the track system comprises a side cover 4. A first endcap 2 and a second end cap 3 is provided at both ends of the curtain tracks 10. The endcap 2 is arranged to close off a curtain track, but comprises also an integrated reverse member to reverse a drive element 31. The drive element may be manually operated but may also be operated by an electric motor 34, as shown in view A. According to the invention, the opportunity to operate the drive element 31 by a motor is generated by providing a drive element having equally spaced voluminous elements. Here, the drive element 31 comprises a cord with balls. The cord is endless and passes through two drive channels of the multiple curtain track system. The balls of the drive element are fixed at a regular distance on the cord. The drive element 31 is guided through a drive channel which is arranged in a curtain track 10. The drive element 31 is arranged to drive a curtain carrier 20. The cord is made endless by a closure 32. The closure is shown in more detail in Fig. 1 B. The closure 32 is made out of plastic and has a longitudinal body 32A. The longitudinal body is flexible to allow the closure to pass through a bended curtain track. The closure comprises at least one gripper 32B which may grip on a voluminous element of a drive element. Here, the gripper 32B is U-shaped. The shown closure 32 is suitable to close a drive element formed by a cord having equally spaced voluminous elements. The voluminous elements may be fitted between two grippers 32B. The cord passes at least one gripper 32B. The drive element may be made endless by inserting at first both ends of the drive element into the closure and subsequently introducing the closure into a curtain track, in particular a drive channel of a curtain track. The dimensions of the closure correspond with the dimensions of the drive channel. The width of the longitudinal body 32A corresponds with the width of an opening at the lower region of the drive channel 12 as shown in fig. 4A. Herewith, the outer contour of the closure fits closely in the curtain track, which further improves the reliability of the multiple track system 1. A drive engagement member 33 is provided to establish a connection between the drive element 31 and the curtain carrier 20. The drive engagement member is shown in more detail in Fig. 1C. The drive engagement member 33 has a gripper 33A which grips between two adjacent positioned voluminous elements on the cord of the driving element. Preferably, the drive engagement member comprises at least three grippers 33A. The grippers 33A are equally spaced on the engagement member 33. Preferably, the distance between two adjacent grippers 'a' corresponds with a length dimension of a gliding element, in particular a curtain runner to obtain a close fit. The close fit of two adjacent grippers 33A around a gliding element improves the connection between the engagement member and the curtain carrier.

The drive channel in a curtain track is positioned relative to the carrier guidance, such that at assembling the drive element in the drive channel and the curtain carrier in the carrier guidance, the drive engagement member 33 automatically engages on the drive element. The drive engagement member 33 is connected to the drive element in a form closed manner. Some play in axial direction of the drive element is allowable. This allows an easy mounting or demounting of the system track.

Apart from the gripper 33A, the drive engagement member 33 is provided with a clamping part 33B to the curtain carrier. The clamping part is arranged opposite the gripper 33A. The clamping part 33B is U-shaped with a long and a short leg. The short leg enables a simple mounting of a curtain carrier to the drive engagement member. The clamping part 33B may be tilted and hooked on to couple the drive engagement member 33 to the curtain carrier. In an alternative embodiment of the curtain carrier, it is also possible to mould the drive engagement member 33 directly to the curtain carrier.

As shown in Fig. 1 , the curtain carrier 20 comprises a gliding element formed by curtain runners 22 at the upper side of the strip. A plurality of curtain runners 22 of at least three curtain runners, but preferably at least 5 curtain runners is provided to obtain a smooth guidance of the curtain carrier through the carrier guidance. A curtain is mountable at a side surface of the curtain carrier beneath the curtain runners 22. The curtain carrier is flat which allows a side by side arrangement of several curtain carriers close to each other in the multiple curtain track system as a panel curtain assembly. The flat curtain carrier 20 may be formed out of a panel strip 21. Here, the strip is made of Velcro material. After mounting the curtain carrier the strip extends into the opening of curtain track to prevent a gap between the suspended curtains and the curtain track. By being introduced into the curtain track the curtain carrier prevents light shining through a gap above the suspended panel curtains.

Fig. 1 further shows that the drive element 31 is disposed in two curtain tracks. The drive element is made endless with the closure 32 and returns in the end caps 2 and 3 mounted at the ends of the curtain tracks. The drive element is connected to a first curtain carrier. The first curtain carrier is positioned in a first curtain track at a front region of the multiple track system. In an alternative manner of driving it is also possible to drive a curtain carrier in the carrier guidance of a curtain track positioned at the back of the multiple curtain system. The first curtain carrier can be moved by operating the drive element 31. A first catch element 36 is mounted at an end of the curtain carrier which can abut against a second catch element 35 during a movement of the curtain carrier. The first catch element 36, which is shown in more detail in Fig. 1 D comprises a projecting part which projects perpendicular to the side surface of the curtain carrier. The first catch element 36 may project at one or at both sides of the curtain carrier, as shown in Fig. 1 D. The catch element in Fig. 1 D has a T-form including a long leg and a transitional leg at one end of the long leg. Two projecting parts form the transitional leg. The long leg forms a mounting body 36Afor connecting the first catch element 36 to the curtain carrier 20. The mounting body may be glued or molded on the curtain carrier, but preferably the body part is snapped to the strip 21. In an embodiment according to the invention curtain runners 36C may be integrated on the first catch element.

The mounting body 36A is splitted in a longitudinal direction for coupling the catch element to a substantially flat curtain carrier. The mounting body may comprise a protrusion 36C at a top region. The protrusions form a curtain runner. The protrusions may be equally spaced along the mounting body. The distance between adjacent protrusions may correspond with a length of a gliding element to obtain a clamping engagement to the corresponding curtain runner at the curtain carrier. As shown in Fig. 1 E, the protrusion can also be used for a closing of the splitable mounting body to get the mounting body fastened to the curtain carrier. Advantageously, the first catch element 36 is made in one piece by e.g. injection moulding. The geometry of the first catch element 36 including integrally several functions allows a cost effective manufacturing.

As shown in Fig. 1A, during a movement of a first curtain carrier comprising the first catch element, the first catch element may couple to a second catch element on a second curtain carrier. The second catch element 35, which is shown in more detail in Fig.1 F is mounted at a distance of at least one centimeter from an end of the second curtain carrier. Herewith the second curtain carrier follows the first curtain carrier with an overlap of at least one centimeter which reduces the amount of light shining through a gap between the first and second curtain carrier. The second catch element 35 forms a projection perpendicular on the side surface of the curtain carrier. The second catch element 35 may be out of one piece, but preferably comprise two injection molded pieces, as shown in Fig. 1 F. A first piece 35A forms the projection and a second piece forms a clip 35B. The clip has a clamping part 35C. The clamping part allows a simple tilt coupling to the curtain carrier. The second piece may be moulded on or glued to the curtain carrier, but preferably the second piece is snapped onto the strip 21. The first piece 35A can be snapped on the clip 35B in at least two positions I or II. Fig. 1 G and Fig. 1 H show respectively the first piece 35C and the clip 35B in more detail. This embodiment of the second catch element 35 allows a flexible system, wherein the embodiment of the curtain carrier 20 can easily be adapted to the occurring circumstances. Fig. 2 shows an embodiment of a bent multiple track system 1 according to the invention. The track system comprises five curtain tracks 10 which are slidably connected to each other. At one side the track system 1 is provided with a side cover 4. The track system has a curvature, wherein no interruption is caused by edges of a connection in a length direction of parts of a curtain track. The carrier guidance 11 remain smooth which allows an excellent movement of the curtain runners. Further, as a result of the improved bending method according to the invention the opening of the carrier guidance has a substantially constant opening width. The bending method according to the invention has reduced the risks on non admittable shear stresses and non admittable deformations of the carrier guidance. In an embodiment according to the invention it is further possible to use a filler. The filler may be used to fill the carrier guidance before the bending operation. It is further possible to fill also at least one drive channel with a filler. As shown in Fig. 2, the curtain carrier 20 is flexible to allow a movement through the curved carrier guidance 11. The plurality of curtain runners of at least eight curtain runners 22 keeps the curtain carrier 20 in a smooth curvature and reduces the risks on folds in the strip 21.

Fig. 2 further shows the first and second catch elements 36 and 35 in an abutted engagement. The first curtain carrier in the curtain track 10 adjacent to the side cover 4 at the front of the system track pulls the second curtain carrier by the complementary catch elements. The catch element 35 is arranged at the back side of the first curtain carrier, so that it does not disturb the esthetic appearance of suspended curtains. It may be advantageous that the catch element 35 can be mounted at both ends of the panel strip 21. The catch element 35 may be mounted at the front or back face of the panel strip 21. Herewith, the catch elements 35 of the multiple track system can be mounted out sight.

Fig. 3a-d show in a schematic view several alternative embodiments of a curtain track provided with connector organs to connect several curtain tracks to each other. The curtain tracks comprise a top face 15 for mounting the curtain track at a mounting surface like a ceiling or window post and further side walls 13 including in between a carrier guidance 11. The top face 15 may be provided with a support organ 17 to connect the curtain track to a support which may be mountable to e.g. a wall or ceiling. The carrier guidance 11 comprises a longitudinally extending opening at the underside of the curtain track 10. The carrier guidance 11 serves to guide a curtain carrier 20. The curtain tracks may be positioned side- by-side to each other and connected to form a multiple curtain track system according to the invention. The connection of the curtain tracks fits the curtain tracks close to each other, but allows a movement of the curtain tracks in a length direction. To obtain the connection the curtain tracks 10 are provided with a pair of complementary connector organs 14A, 14B at the side walls 13. Fig. 3a shows a first connector organ 14A at a first side wall having an extending rill and a second connector organ 14B having a complementary groove. The rill of the first connector organ is insertable into the groove of the second connector organ. By inserting and rotating the curtain tracks close to each other, the first connector organ of a first curtain track snaps into the second connector organ of a second curtain track and the connection is established. Herewith, a connection is provided which still permits a movement of adjacent curtain tracks along each other, but keeps the curtain tracks side by side. Fig. 3b and 3c show in a schematic cross sectional view alternative embodiments of the curtain track 10. The curtain track 10 is provided with a pair of complementary connector organs 14A and 14B. The connector organs 14A, 14B are arranged as a groove which extends over substantially the whole length of the curtain track. In Fig. 3B the connector organs cover about half of the side walls 13 and in Fig. 3C the connector organs form a deeper groove and cover about the whole side wall of the curtain track. Advantageously, the embodiments of the curtain tracks allow a connection of several equally arranged curtain tracks to each other.

Fig. 3d shows in a schematic cross sectional view a similar curtain track which is further provided with a drive channel 12 for receiving a drive element. The cross section of the drive channel is partly conical for receiving and guiding a drive element comprising a cord with balls. The balls may run smoothly over the surface formed by the conical part of the drive channel 12. The drive channel 12 is positioned above the carrier guidance 11 at a constant distance. The constant distance between the carrier guidance and the drive channel enables an automatically form closed connection between a drive element and a curtain carrier.

Fig. 3E shows in a schematic cross sectional view a curtain track comprising two carrier guidances 11. The curtain track 10 has a top face 15 and side walls 13. Further the curtain track comprises a intermediate wall 16 which extends parallel to the side walls 13. The side walls are provided with a pair of complementary connector organs 14A, 14B. Several curtain tracks 10 having this cross section may be connected side by side by the connector organs 14A, 14B and bent together. The curtain track may be bent into an angle of at least 225° over a radius of at least 20cm.

Fig. 4a - 4c show in several cross sectional views a preferred embodiment of a curtain track 10 according to the invention. Advantageously, the cross sectional geometry is such that the curtain track can be manufactured by an extrusion process. The curtain track comprises a top face 15 and side walls 13. The curtain track has a hollow innerspace with an opening at the underside. The opening extends in an axial direction and defines a carrier guidance 11. Further, the innerspace is provided with a drive channel 12. The drive channel 12 is formed by two ribs which bend towards each other. The side walls 13 are provided with a pair of complementary connector organs 14A, 14B.

A first connector organ 14A of a first curtain track fits into a second complementary connector organ 14B of a second curtain track. Fig. 4b shows an assembly of two side by side connected curtain tracks, wherein a third curtain track is inserted under a small angle. By rotating the third curtain track into a straight position, the third curtain track will fit into the series of already connected curtain tracks. As shown in Fig. 4a, the second connector organ 14B comprises a groove 141 B and opposite the groove a projection 142B. The projection extends perpendicular to the side wall 13. At the end the projection 142B is rounded or chamfered which allows an improved receiving of the first connector organ 14A. Adjacent to the chamfered end the projection 142B is provided with a projection groove 143B. As shown in Fig. 4b a receiving space is defined by the projection groove 143B and the groove 141 B of the second connector organ. The first connector organ 14A is dimensioned such that it fits within the defined space. The geometry of the projection may advantageously provide a reliable connection of the first connector organ 14A into the second connector organ 14B which is able to withstand bending forces.

Fig. 4c shows in a cross sectional view four connected curtain tracks. Fig. 4 shows two curtain tracks which are provided with a drive channel and two connected curtain tracks without a drive channel. Mostly, just two curtain tracks including a drive channel are necessary to mount a drive element for opening and closing curtains. The remaining curtain tracks may be arranged without a drive channel which may give a reduction in material costs. Fig. 5 shows in a cross sectional view an alternative embodiment of connected curtain tracks. The multiple track system according to the invention comprises two kind of curtain tracks, a first curtain track and a second curtain track. The first curtain track comprises two opposite side walls which are provided with a connector organ. The first curtain track has at both sides a connector organ formed by two projecting ribs. The ribs are extending perpendicular from the side wall. The first curtain track is connectable to a second curtain track by pressing the projecting ribs into grooves of a second connector organ provided in a top face of the second curtain track.

Many variants are possible in addition to the illustrated embodiment without leaving the scope of protection defined by the appended claims. Advantageously, the multiple curtain track system according to the invention may be used in combination with a flexible panel strip as a curtain carier. However, it may also be advantageous to use the flexible panel strip in combination with otherwise arranged track systems. The flexible panel strip may e.g. be used in combination with a track system, wherein the tracks are separately mounted to a mounting surface, like a ceiling, window framework etc. or wherein the tracks are fixed to each other and integrated into one multiple track system as shown in

US6.892.783. The flexible panel strip may also be advanteous in combination with a track system having only a single track. Thus, the curtain carrier comprising a flexible panel strip as a carrying body in a track system includes potential patentability on its own merits.

In a variant according to the invention curtain runners may be integrated with a carrier body e.g. a strip of a curtain carrier or with the first catch element or drive engagement member. The complete curtain carrier may be moulded including integrated curtain runners, an integrated catch element and an integrated drive engagement member.

Although the multiple curtain track system according to the invention provides a lot advantages as a complete system, singular components do also provide advantages when taken in isolation. For example, the above presented curtain track, curtain carrier, closure, drive engagement member and catch elements do include advantageous merits in itself. The components can be used in conventional curtain systems while profiting of inhered advantageous properties of the components.

Thus, according to the invention, a multiple curtain track system is provided which allows curved arrangements of the curtains. The risks on damages during the bending process may strongly be reduced.