System for dividing off areas of a room   

BACKGROUND OF THE INVENTION

1. Field of Invention

The invention relates to a device for dividing off areas of a space, with at least one ceiling rail and/or floor rail and/or wall rail which has at least two rail parts and with at least one web of film or fabric which can be connected to the ceiling rail and/or floor rail and/or wall rail, and at least the first rail part and at least the second rail part of a rail, which second rail part is adjacent to the first rail part, can be connected to one another and can be fixed in their position relative to one another.

2. Description of Related Art

A device of the initially mentioned type is already known from International Patent Application Publication WO 2006/002705 A1. In the known device, the individual rails for the ceiling, walls and floor are made such that they can be pushed against one another and relative to one another. The rail parts which can be telescoped into and out of one another make it possible to completely separate one region of a space which is to be renovated relative to other regions of the space. The individual rail parts create a peripheral frame which adjoins the ceiling, the walls and floor and to which a film can be attached in order to enable dirt-proof separation of the regions of the space. Continual adjustment of the individual rails is possible in that there are two different types of rail profiles, one profile engaging the other profile and the profiles in this way being movable relative to one another. The rail profiles are then screwed to set a certain rail length.

The known device is characterized in that it is easily possible to divide off areas of a space without gaps and thus free of dirt.

SUMMARY

The object of this invention is to make available an alternative version which is simple and economical and at the same time keeps out dirt.

This object is achieved in accordance with the invention in a device in which adjacent rail parts can be connected positively and/or nonpositively to one another simply by mutual superpositioning or overlapping of the rail parts and by subsequently pressing the overlapping rail parts together in the transverse direction of the rails, without the need for a screw fitting or the like as a separate connecting means. In contrast to the device which is known from International Patent Application Publication WO 2006/002705 A1, in which the rail parts are pushed into one another and are then fixed relative to one another, in the device in accordance with the invention overlapping rail parts are positively and/or nonpositively connected solely by pressing together. Insertion of the rail parts and also insertion or withdrawal of the rail parts which are connected to one another are neither provided nor possible since the rail parts can no longer be moved relative to one another after pressing together and the resulting connection. In this way, the mounting and dismounting of the rail formed of a plurality of rail parts are simplified.

In order to adjust the length of the rails to the width of the ceiling or floor or the height of the wall, it is simply necessary to arrange a sufficient number of rail parts in the lengthwise direction next to one another and overlapping in regions such that the overall arrangement of rail parts yields a rail with the desired width and height. In the overlapping region, the rail parts are then connected positively and/or nonpositively to one another by pressing together so that the rail is relatively stable. The positive and/or nonpositive connection of the rail parts by superposition and pressing together enables a simple structural configuration of the rail parts; this contributes to low production costs of the device in accordance with the invention.

In the simplest case, two rails parts can be sufficient to create a rail which extends over the entire width of the floor or ceiling and height of the wall. It is, of course, also possible for more than two rail parts to have to be connected to one another in order to obtain the required width or height.

To achieve a given length of the rail, in one preferred embodiment of the invention, it is provided that, after pressing together the overlapping rail parts, they are interconnected essentially immovably relative to one another in the lengthwise direction of the rail. Due to the fixed adjustment of the rail parts relative to one another, a rail length, once it has been set, remains constant even in the installation state. The degree of overlapping is preferably continuously adjustable; this means that the rail parts can be connected to one another for any chosen degree of overlapping. This presupposes a corresponding execution of the rail parts. But, fundamentally, it can also be provided that the rail parts can still be moved relative to one another in the lengthwise direction even after being pressed together; this allows fine adjustment of the length of the rail to the required width of the ceiling or floor and height of the wall.

There can be catch, squeeze, clamp or VELCRO® hook and loop connections for positive and/or nonpositive connection of the rail parts. Fundamentally, it is however also possible for two rail parts to be connected to one another by an adhesive connection. Preferably, the connection of the rail parts is made such that simple dismounting of the rails is possible at a later time without its being necessary to destroy the rail parts.

In one preferred embodiment, the first rail part has a base profile and the second rail part has a connecting profile which is complementary to the base profile. The base profile and the connecting profile can have complementary deformation areas such that simply pressing together the overlapping base profile and connecting profile yields a positive and/or nonpositive connection. Preferably, the first rail part and the second rail part are each made in one piece; this contributes to low production costs and simplifies installation.

The first rail part and/or the second rail part can have fundamentally the same profile over the entire length; this easily allows the rail parts to be connected to one another for any selected degree of overlapping.

If there is a catch connection for purposes of connecting the overlapping rail parts by pressing together, the first rail part can have at least one catch projection which is pointed to the outside on a region of the rail part which is preferably near the ceiling, floor or wall, therefore pointed to the outside, which can be positively and/or nonpositively connected to a corresponding catch recess of the second rail part. The catch projection being in the vicinity of the ceiling, floor or wall ensures that the catch projection is not in the way when the film is attached to the rail parts. Moreover, the first rail part can have at least one catch recess which is pointed to the inside in a region of the rail part which is preferably away from the ceiling, floor or wall, the catch recess of the first rail part being positively and/or nonpositively connectable to the catch projection of the second rail part. The connection of the film to the rail part is not adversely affected by the catch recess which is pointed to the inside.

The catch projection and/or catch recess can extend over the entire length of the rail part; this relates to both rail parts and enables connection of the rail parts at any degree of overlapping.

In the mounted state of the rail, in the overlapping region of the overlapping rail parts, there can be at least one engagement slot for a tool which is to be placed between the rail parts and which can be used for simplified release of the connection when the rail is dismounted. This presupposes a corresponding execution of at least one of the rail parts or suitable profiling. The engagement slot can extend over the entire width of the overlapping region and is provided preferably on the region of the rail parts which is away from the ceiling, floor or wall. In this way, it is easily possible to again separate interconnected rail parts from one another after use in order to stow the device in accordance with the invention in a space-saving manner. Otherwise, repeated connection and disconnection of the rail parts can be necessary when the selected degree of overlapping has to be corrected.

In order to be able to connect a web of film, a tarpaulin or the like to the rail parts, at least the first rail part and/or the second rail part can have at least one adhesive tape which extends at least partially in the lengthwise direction of the rail part, the adhesive tape being provided on the outside of the rail part. Arrangement of adhesive tapes in several rows is also possible in order to enable repeated use of the rail or repeated connection of the web of film or the tarpaulin to the rail parts. The width of the adhesive tape or tapes can extend at least over half the height of the rail part in order to make available a sufficient adhesive area. To hold the adhesive tape the rail part can have a depression which extends in the lengthwise direction on the outer side, preferably the adhesive tape being inserted essentially superficially flush into the depression. By pressing the film or tarpaulin onto the adhesive surface, a connection is then produced between the film and the respective rail part. If the outside of the rail part and the outside of the adhesive strip are aligned, when the overlapping rail parts are being connected, obstruction by the adhesive tape does not occur. Otherwise it goes without saying that, in the original state, there is a removable protective layer on the adhesive tape.

For placement between the ceiling rail and the floor rail, there can be at least one especially continuously adjustable support rod by which sufficient contact pressure between the opposite rails is ensured. The vertical adjustability should preferably be continuous, for reasons of handling, its being recommended that the rod can be fixed in any set length by way of a screw connection. For simplified connection to the rails on their upper and/or lower end, the support rod can have connecting means for positive and/or nonpositive connection of the support rod to the other complementary connecting means of the rail, the connecting means of the support rod and the other connecting means of the rail being made such that only by turning the support rod around its lengthwise axis is a frictional connection and/or a force fit in the profile effected. In this way, especially simple bracing of the support rod between opposing rails is possible.

The features of the type described above relative to the support rod as such and the following features of the support rod have their own inventive importance, i.e., independently of the above described features which relate to the rail.

In one embodiment of the invention, it can be provided that the support rod has a fastening part pivotally connected on one end, the fastening part having connecting means for positive and/or nonpositive connection to other complementary connecting means of the rail, and preferably, the connecting means of the fastening part and the other connecting means of the rail being made such that a frictional connection and/or a force fit in the profile of the rail effected only by twisting the fastening part around its lengthwise axis. Since the fastening part is been connected to the rail, it is possible to pivot the support rod relative to the fastening part. In this way, the bracing of the support rod between two opposing rails is simplified. Here, it can be provided that the support rod is attached on one end to the fastening part on the rail and on the other end has connecting means which make it possible to effect a frictional connection and/or a force fit in the profile of the rail by turning the support rod around its lengthwise axis on the other end of the support rod. The material execution of the support rod or fastening part, on the one hand, and the rail on the other, which execution is necessary for this purpose, is described below simply using the example of the support rod. It goes without saying that the described features can be provided accordingly in a fastening part.

In one preferred embodiment, the support rod has at least one projection on its end as the connecting means which can be fixed in the rail by turning the support rod around its lengthwise axis in the engagement region as a further complementary connecting means. In this way, a positive and nonpositive connection between the support rod and the rail is easily enabled. In this connection, it is of course possible for the support rod to have the corresponding connections on both ends. If the head and foot of the support rod are made the same, the support rod can be connected to the rail at either end; this further facilitates mounting of the device in accordance with the invention. Moreover, it is preferably provided that the support rod can be inserted or screwed into the engagement region of the rail anywhere on the rail; this further simplifies installation.

In an especially simple and economical embodiment, it is provided that the first rail part is made U-shaped in cross section with two opposite side walls and that, preferably, the engagement region for the support rod is formed between the bottom of the rail part which connects the side walls and opposite extensions which are provided on the inside of the side walls. The extensions extend in the lengthwise direction of the first rail part especially over the entire length so that the support rod in the lengthwise direction of the rail part can be connected to it at any location.

On the projection of the support rod, there can be outer feed bevels which run in the shape of an arc segment. In this way, it is possible to connect the support rod to a rail or to brace it in the rail by screwing it in with a low expenditure of force.

The support rod, on the opposite jacket sides, can have at least one projection which is molded to the support rod, the opposite projections being located in a common plane and spanning a common cross-sectional area with two straight outer sides which are located oppositely parallel and with two arc segment-shaped outer sides which are located diagonally opposite. Moreover, the cross sectional area which has been fixed by the contour of the projections can have two diagonally opposite edges with outer sides which run essentially at a right angle to one another, and after connecting the support rod to the rail by turning the support rod around its lengthwise axis, at least the edges of the projections lie against the side walls; this leads to clamping of the support rod in the rail. In order to enable simple insertion of the support rod with one end into the rail, the maximum width of the cross-sectional area corresponds essentially to the distance between adjacent side walls of the rail, and the minimum width of the cross sectional area should be smaller than the distance between the above described extensions or the other projections on the rail.

In the support rod, preferably on at least one end of the support rod, there can be at least one spring means which acts in the lengthwise direction of the support rod. This spring means facilitates not only insertion of the support rod, but also ensures permanent pressing of the respective rail.

Preferably, the first rail part has two identically made side walls which are located mirror-symmetrically to one another. In this way, it is easily possible, if necessary, to connect the second rail part to one side wall or to the other side wall; this further simplifies mounting of the rail. For example, each side wall can have a catch projection, and optionally, a catch recess, and catch projections and catch recesses of opposing side walls can each be located opposite on another so that a mirror-symmetrical structure of the first rail part results.

Furthermore, there are preferably catch recesses on the free end of the side walls and extensions in the region of the side walls which is near the ceiling, floor or wall, the clearance distance between opposite side walls at the height of the catch recesses being greater than the clearance distance between the extensions on the side walls. In this way, the insertion of the support rod into the engagement region of the first rail part is not obstructed by the inwardly pointed catch regions on the side walls which are intended for forming a positive and/or nonpositive connection.

If the first rail part has a U-profile, each side wall, preferably on the outside, can have a depression or a groove which is intended for accommodating an adhesive tape. In this way, the first rail part can necessarily be connected from one side or the other side to a film or tarpaulin. This contributes to simplified dividing-off of an area of a space and enables re-use of the rail. Otherwise, the second rail part can be made in the same way with respect to holding, the second rail part having a corresponding depression at least on its outside, optionally also on its inside. In this regard, the outer depression is used to hold an adhesive tape, while the inner depression is ultimately used such that the adhesive tape which is located on the outside of the first rail profile in this region can be held in the inside depression and does not hinder the connection between the two rail parts.

Preferably, there is a depression between the catch projection on the end of the side wall near the ceiling, floor or wall, and the catch recess on the free end of the side wall. The width of the depression corresponds preferably at least to the width of the adhesive tape or a plurality of strips of adhesive tape which are located next to one another in the lengthwise direction.

The rail parts can be obtained or produced from plastic by extrusion, and at least one sealing means can be injected onto the rail part for contact against the ceiling, floor or wall immediately after extrusion. This contributes to very low production costs of the rail parts. The sealing means largely precludes passage of dirt particles between the ceiling, floor or wall and the rail.

In order to ensure sufficient contact pressure of the rail against the ceiling and/or the floor, there can be at least one diagonal brace for preferably detachable fastening to the wall rail and the ceiling rail or the floor rail. In accordance with the invention, it is provided that, on preferably both ends of the diagonal brace, there are tension means for fixing the diagonal brace in the rails and that the tension means are held captively on the diagonal brace or are made integrally with it. These tension means make it easily possible to brace the diagonal brace in the corner region between the ceiling and wall rail or the wall and floor rail. Moreover, simple dismounting of the rail arrangement is possible. The fastening of the tension means to the diagonal brace ensures high user comfort.

In particular, there are a host of possibilities for embodying and developing the device in accordance with the invention as can be seen by reference to the following description of preferred embodiments of the invention with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the device in accordance with the invention,

FIG. 2 is a cross-sectional view of a first embodiment of a rail of the device taken along line I-I in FIG. 1,

FIG. 3 is a cross-sectional view of another embodiment of a rail made for use in a device for dividing off areas of a space,

FIG. 4 is a cross-sectional view of another embodiment of a first rail part,

FIG. 5 is a cross-sectional view of another embodiment of a second rail part,

FIG. 6 is a partial cross-sectional view of a support rod which is connected to the rail, from the side,

FIG. 7 is a partial cross-sectional view of a support rod which is connected to the rail, from overhead,

FIG. 8 is a partial cross-sectional view of a support rod which is connected to the rail in the region of the lower end of the support rod,

FIG. 9 is a partial cross-sectional view of the support rod shown in FIG. 8, from the side, and

FIG. 10 is the end of the support rod shown in FIG. 1 in a cross-sectional view taken from overhead along A-A in FIG. 8.

DETAILED DESCRIPTION

FIG. 1 shows a device 1 for dividing off areas of a space with a plurality of ceiling rails 2a, 2b, floor rails 3a, 3b and wall rails 4. The ceiling rail 2a, the floor rail 3a and the wall rails 4 are made in several parts. The ceiling rail 2b and the floor rail 3b are made in one part. Between the opposing ceiling rails 2a, 2b and floor rails 3a, 3b there are support rods 5 whose length is continuously adjustable and which on their upper and lower end have connecting means (not shown) for positive or nonpositive connection to complementary connecting means of the rails 2a, 2b, 3a, 3b. The support rods 5 brace the ceiling rails 2a, 2b and the floor rail 3a, 3b against the ceiling and the floor. Moreover, there are diagonal braces 6 to ensure sufficient contact pressure in the corner region between an adjacent ceiling rail 2a, 2b and the wall rails 4 and between the wall rails 4 and the floor rails 3a, 3b. Not shown is the fact that, in particular, each end of the diagonal braces 6 has a tension means for fixing a respective one of the rails 2a, 2b, 3a, 3b, 4, the tension means being captively held on the diagonal braces 6.

The structure of the ceiling rail 2a is described by way of example below. The structure of the ceiling rail 2a shown in FIG. 2 corresponds essentially to the structure of the floor rail 3a and the structure of the wall rail 4. The ceiling rail 2a, in the embodiment shown in FIG. 1, is composed of two rail parts 7 with a base profile and a rail part 8 with a connecting profile. In this regard, it is provided that adjacent rail parts 7, 8 are connected positively and nonpositively to one another by mutual superposition of the rail parts 7, 8 in the lengthwise direction of the rail and by subsequently pressing the overlapping sections of the rail parts 7, 8 together in the transverse direction of the rail.

The ceiling rail 2a and the floor rail 3a as well as the wall rails 4 have the same rail parts 7, 8; this greatly facilitates installation of the device 1. The ceiling rail 2b and the floor rail 3b have a single rail part 7 whose length corresponds essentially to the depth of the space which is divided off. Fundamentally, it is also possible, here, to provide a plurality of rail parts 7, 8 in order to be able to divide off an area of space with a greater depth.

The first rail part 7 has a U-profile with two side walls 9 and a bottom 10. The second rail part 8 is made with one leg and has a side web 11 with an extension 12 on the end near the ceiling. Sealing lips 13 are welded to the extension 12 and the bottom 10 in order to preclude the passage of dirt particles between the ceiling which is not shown in FIG. 1 and the ceiling rail 2a in the mounted state.

In the region near the ceiling, on the side walls 9 of the first rail part 7 on the outside, there are catch projections 14 which are connected positively and nonpositively to the catch recess 15 on the side web 11 of the second rail part 8. On its free end, each side wall 9 has a catch recess 16, which is connected positively and nonpositively to a complementary catch projection 17 on the side web 11 of the second rail part 8. The catch projections 14, 17 and the catch recesses 15, 16 extend over the entire length of the rail parts 7, 8 so that it is easily possible to connect the rail parts 7, 8 to one another by pressing them together at any degree of overlapping. In FIG. 2, the left side wall 9 of the first rail part 7 is connected to the side web 11 of the second rail part 8. Likewise, it is easily possible to connect the second rail part 8 to the right side wall 9 of the first rail part 7; this simplifies mounting of the ceiling rail 2a.

Between the catch projection 14 and the catch recess 16 each side wall 9 on the outside has a depression 18 whose width corresponds to at least half the width of the side wall 9. An adhesive strip (not shown) with an external removable protective strip and which is intended to cement the first rail part 7 to a web of film and/or tarpaulin can be embedded in the depression 18. Embedding the adhesive strip in the depression 18 precludes obstruction by the adhesive strip for positive and nonpositive connection of the rail parts 7, 8. In this regard, it is such that there can be other adhesive surfaces on the side web 11 of the second rail part 8 in order to enable attachment of the web of film which is continuous in the lengthwise direction to the ceiling rail 2a.

For easy release of the rail parts 7, 8, there is an engagement slot 19 in the installed state of the ceiling rail 2a. Using a screwdriver or the like it is easily possible to separate the interconnected rail parts 7, 8 from one another and dismount the ceiling rail 2a.

Moreover, the first rail part 7 has an engagement region 20 which is bordered toward the ceiling by the top wall 10 and in the direction to the floor by inwardly pointed extensions 21 on the side walls 9. To connect the support rod 5 (shown in FIG. 1) to the first rail part 7 it is provided that the support rod 5 is inserted with one end into the engagement region 20 and then is turned around its lengthwise axis. In doing so, there is a positive and nonpositive connection between an outer projection on the end of the support rod 5 and the extensions 21, the thickness of the projection being larger than the height of the engagement region 20. In order to enable simple insertion of the support rod 5 with its end into the engagement region 20, it is also provided that the clearance distance d1 between the opposite side walls 9 at the height of the catch recesses 16 is larger than the clearance distance d2 between the opposing extensions 21.

FIG. 3 shows a simplified embodiment of a ceiling, floor or wall rail 24 which has been formed from two rail parts 22, 23. The rail 24 corresponds essentially to the ceiling rail 2a shown in FIG. 2, for connection of the rail parts 22, 23; however, there is only one catch connection in the ceiling, floor or wall region. The rail part 23 is made essentially L-shaped with two legs 23a, 23b and on the leg 23a, it has a catch recess 25 which, in the installed state of the rail 24, a catch projection 26 of the rail part 22 engages. The horizontal leg 23b of the rail part 23 has an extension 27 on its free end which, in the installed state of the rail 24, lies against the ceiling, floor, or the wall and is intended as a support for the rail part 23.

FIG. 4 shows the profile of a rail part 7a in cross section. This profile differs from the profile of the first rail part 7 shown in FIG. 2 in that, in addition to the extensions 21, there are two other extensions 21a on opposite sides which project less than the extensions 21. In this case, there is a groove 21b on each side wall 9 between the respective projection 21 and the respective projection 21a, and bracing can take place with the projections on the support bars engaged in the grooves 21b. Otherwise, the other projections 21a are used as reinforcement.

FIG. 5 shows the profile of a second side part 8a. One difference from the embodiment shown in FIG. 2 is that there is a depression of little depth on the inner side 8b of the second rail part 8a, while on the outer side 8c there is another depression 18b for holding and placing an adhesive tape. The depression 18a is ultimately used to hold the possibly projecting region of the adhesive tape which is located in the depression 18 of the first rail part 7, 7a so that catching can be easily undertaken.

FIG. 6 shows a partial cross sectional view of a support rod 5 which is attached to the rail part 7b of the ceiling rail 2a, 2b. The support rod 5, for example, has a fastening part 28 with a grip section 29 on the upper end. The fastening part 28 also has connecting means for positive and/or nonpositive connection to further complementary connecting means of the rail part 7b, the connecting means of the fastening part 28 and the other connecting means of the rail part 7b being made such that, only by turning the fastening part 28 around its lengthwise axis Y1, is a frictional connection and/or a force-fit effected in the profile of the rail part 7. When the grip section 29 turns, the projections 30, 31 shown in FIGS. 6 & 7 and the other projection 36 as well as another projection of the fastening part 28 which is not shown engage the engagement regions 32, 33 and other engagement regions 37, 38 of the rail part 7b (FIG. 8), which will be explained detail below. In this connection, it is such that the connecting means of the fastening part 28 correspond to the connecting means of the support rod 5 which are provided on the lower end of the support rod 5 for positive and/or nonpositive connection of the support rod 5 to the rail part 7b of the floor rail 3a, 3b.

Moreover, FIGS. 6 & 7 show that the support rod 5 and the fastening part 28 are hinged to one another by a hinge 34 so that it is possible to pivot the support rod 5 relative to the rail part 7b after attachment of the fastening part 28 with the ceiling rail 2a, 2b. In this way, the fastening of the support rod 5 to the free end on the floor rail 3a, 3b is facilitated.

After attaching the fastening part 28 to the rail part 7b of a ceiling rail 2a, 2b, the support rod 5 is moved into the vertical position and then by turning around the lengthwise axis Y2, its lower end is fastened in the rail part 7b of the floor rail 3a, 3b. The rail parts 7b of the ceiling rail 2a, 2b, on the one hand, and of the floor rail 3a, 3b on the other, are made the same. Fundamentally, the support rod 5 can therefore also be attached using the fastening part 28 to a floor rail 3a, 3b or a wall rail 4.

FIG. 8 shows the free end of the support rod 5, the support rod 5 being tightly connectable to the rail part 7b by turning. To do this, the support rod 5 has projections 30, 31 and other projections 35, 36 on its free end which correspond to the projections 30, 31, 35, 36 on the fastening part 28. The projections 30, 31 engage the engagement regions 32, 33 of the rail part 7b, while the projections 35, 36 engage the other engagement regions 37, 38. The rail part 7b has oppositely arranged projections 39, 40 with the same width. The projections 39, 40 are provided on the inner sides of the side walls 41, 42 of the rail part 7b. The projections 39, 40 on the one hand, and the projection 40 and the bottom 43 of the rail part 7b, on the other, border the engagement regions 32, 33 and the other engagement regions 37, 38. As has already been pointed out, the lower end of the support rod 5 shown in FIG. 8 and the upper end of the fastening part 28 which is intended for attachment to the rail part 7b are made the same; this makes it possible, with the same execution of the rail parts 7b of the ceiling rail 2a, 2b and the floor rail 3a, 3b, to attach the fastening part 28 or the support rod 5 to the ceiling rail 2a, 2b or the floor rail 3a, 3b, if necessary.

FIG. 8 also shows that the support rod 5, in the region of the free lower end has a spring means 44 which acts in the lengthwise direction Y2 of the support rod 5 and a retaining pin 47 which acts against the spring means 44, the retaining pin 47 being tightly connected to the outer part 46 and being movably guided in a slot 47a of the inner part 45. In this way, the support rod 5 can be easily braced between the ceiling rail 2a, 2b and the floor rail 3a, 3b.

The projections 30, 31 and the other projections 35, 36, in the lengthwise direction of the rail part 7b, have feed bevels 48, 49 which are inclined in the direction toward the bottom 43 of the rail part 7b. The feed bevels 48, 49 facilitate turning of the projections 30, 31 and the other projections 35, 36 into the engagement regions 32, 33 and the other engagement regions 37, 38 of the rail part 7b, respectively.

FIG. 10 shows that the two projections 30, 31 which are located in a common plane, on the one hand, and the other projections 35, 36 on the other (not shown) span a cross-sectional area with two straight outer sides 50, 51 which are located oppositely parallel and with two arc segment-shaped outer sides 52, 53 which are located oppositely parallel. The other projections 35, 36 correspond to the projections 30, 31. The cross-sectional area, moreover, has two diagonally opposite edges 54, 55 with outer sides 51, 52 and 50, 53 which run essentially at a right angle to one another, after connecting the support rod 5 to the rail part 7b by turning the support rod 5, the projections 30, 31 rest against the side walls 41, 42 of the rail part 7b at least in the region of the edges 54, 55. The maximum width b1 of the cross-sectional area in the region of the middle transverse axis X1 of the support rod 5 corresponds essentially to the distance between the adjacent side walls 41, 42 of the rail part 7b. The minimum width b2 of the cross-sectional area in the direction of the middle transverse axis X1 is conversely smaller than the distance between the projections of the rail part 7b. In this way, it is easily possible, in a first position of the support rod 5, to insert its free end into the region between the opposing projections 39 of the rail part 7b, and by turning at least the inner part 45 of the support rail 5 around the lengthwise axis Y2 into a second position, to produce a positive and nonpositive connection between the support rod 5 and the rail part 7b. It goes without saying that the intended type of connection between the support rod 5 and the rail part 7b, on the one hand, and the connection of the fastening part 28 to the rail part 7b, on the other, presuppose that the support rod 5 has at least two support rod parts 45, 46 which can be turned relative to one another around the common lengthwise axis Y2.