Channels, tubings, cable ladders and similar objects inside buildings often needs to be enclosed with for instance gypsum boards for fire safety reasons or esthetical reasons. Said objects are often placed under a ceiling or in wall corners. The work to enclose these objects is at present carried out by fastening crossbars of wood or sheet-metal in ceiling or wall, for instance by means of nails, screws or the similar, whereupon suitably cut gypsum boards are secured to the crossbars by screws. After the mounting of the gypsum boards, sealing, puttying, painting etc. is carried out.

OBJECT OF THE INVENTION The object of the present invention is to make possible a simpli- fication of the work to mount gypsum boards and other plate- shaped elements, for instance at an angle to a wall or a ceiling.

SUMMARY OF THE INVENTION According to the invention, said object is achieved by means of a mounting rail provided with a groove designed to receive an edge section of a plate-shaped element, which groove has two essentially parallel sidewalls intended to bear on either side of the plate-shaped element when en edge section thereof is in- serted into the groove, at least one of said sidewalls being pro- vided with holding members, which protrude from the associated sidewall into the groove and are intended to penetrate into the plate-shaped element when it is pressed into the groove in a di- rection towards the bottom of the groove so as to thereby hold said edge section in place in the groove. When mounting a plate-shaped element using a mounting rail according to the in- vention, the plate-shaped element is intended to be placed with an edge section extending along the groove of the mounting rail in order, subsequently, to be pressed into the groove in a direc- tion towards the bottom of the groove. Hereby, it will be possible to fasten a plate-shaped element to the mounting rail in a rapid and simple manner. Due to the penetration into the plate-shaped element of the holding members protruding from the sidewall, the plate-shaped element will automatically be held in place in the mounting rail when the edge section of the plate-shaped element is pressed into the groove, which considerably facili- tates the mounting work.

According to a preferred embodiment of the invention, the re- spective holding member has a cutting edge, which is intended to cut into the plate-shaped element when en edge section thereof is inserted into the groove. Hereby, the penetration of the holding members into the plate-shaped element is facili- tated.

According to a further preferred embodiment of the invention, the respective holding member consists of a cutting tooth, which preferably is angled obliquely outwards from the associated

sidewall in the direction towards the bottom of the groove. The cutting tooth is suitably, as seen in a projection against the as- sociated sidewall, tapered in the direction towards the bottom of the groove so that the end of the cutting tooth facing the bottom of the groove forms a sharp tip. Hereby, holding members are achieved in a simple manner, which holding members are capa- ble of effectively cutting into a plate-shaped element at the same time as they give a relatively low resistance when the edge section of the plate-shaped element is pressed into the groove.

According to a further preferred embodiment of the invention, the respective holding member is formed by punching of the as- sociated sidewall. Hereby, it will be possible to manufacture the mounting rail in a simple and cost-effective manner. The above mentioned type of cutting teeth are particularly suited to be formed in a sidewall of the mounting rail by punching.

According to a further preferred embodiment of the invention, the bottom of the groove is provided with through holes in order to make possible a fastening of the mounting rail to a support surface, such as a wall, a ceiling or the similar.

According to a further preferred embodiment of the invention, one sidewall of the groove of the mounting rai) has a shorter extension perpendicular to the bottom of the groove than the other sidewall, the shorter sidewall having a flange at its end facing away from the bottom of the groove, which flange is an- gled obliquely outwards from the sidewall, the angle between the flange and an extension of the sidewall being between 10- 90°, preferably between 30-45°. The oblique flange facilitates the insertion of the edge section of a plate-shaped element into the groove.

According to a further preferred embodiment of the invention, the flange is provided with a through hole for fastening the

mounting rail to suspension members, such as hooks or the similar. Hereby, it will in a simple manner be possible to rein- force the fastening of the mounting rail to a support surface, such as for instance a wall or a ceiling.

According to a further preferred embodiment of the invention, at least one of the sidewalls of the groove is provided with through holes in order to make possible fixing to the mounting rail, by means of fastening elements, such as screws or the similar, of a plate-shaped element mounted in the groove. Hereby, it will in a simple manner be possible to reinforce the fastening of the plate-shaped element to the mounting rail.

Further preferred embodiments of the inventive mounting rail will appear from the dependent claims and the subsequent descrip- tion.

The invention also relates to a method according to claim 14 for mounting plate-shaped elements, such as for instance gypsum boards, at an angle to a support surface, such as a wall, a ceil- ing or the similar.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will in the following be more closely described by means of embodiment examples, with reference to the appended drawings. It is shown in: Fig 1 a schematical perspective view of two gypsum boards mounted with mounting rails according to an embodi- ment of the invention, Fig 2 a schematical cross-sectional view of a mounting rail according to a preferred embodiment of the invention,

with a gypsum board in a first position before the in- sertion into the groove of the mounting rail, Fig 3 the mounting rail according to fig 2, with the gypsum board in a second position before the insertion into the groove of the mounting rail, Fig 4 the mounting rail according to fig 2, with the gypsum board inserted into the groove of the mounting rail, Fig 5 a schematical perspective view of the mounting rail according to fig 2, Fig 6 a schematical perspective view of a mounting rail of corner-type according to a first embodiment, and Fig 7 a schematical perspective view of a mounting rail of corner-type according to a second embodiment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Two gypsum boards 1 mounted with the aid of mounting rails 2, 3 according the present invention are illustrated in fig 1. A first gypsum board 1 is here mounted to a support surface in the form of a wall 4a with the aid of a first mounting rail 2 and a second gypsum board 1 is mounted to a support surface in the form of a ceiling 4b with the aid of a second mounting rail 2.

Said first and second mounting rails 2 here have identical de- sign. The gypsum boards 1 are joined to each other at their outer edges with the aid of a mounting rail 3 of corner-type, i. e. a mounting rail which forms a corner of the unit formed by the assembled gypsum boards. Gypsum boards mounted in the manner illustrated in fig 1 could for instance be arranged to en- close one or several pipes or other elongated objects. In fig 1, the gypsum boards are mounted to enclose a channel extending

in the horizontal direction. It is, however, realised that gypsum boards mounted in a manner corresponding to the manner illus- trated in fig 1 as well could be arranged to enclose a channel extending in the vertical direction, for instance in a wall corner, or in any other direction.

A mounting rail 2 according to the invention for fastening a plate-shaped element to a support surface, such as for instance a wall or a ceiling, will in the following be more closely de- scribed with reference to fig 2-5. In the following, the plate- shaped element is conceived to be constituted by a single gyp- sum board, but the inventive mounting rail could also be dimen- sioned for mounting a double gypsum board or for mounting a plate-shaped element of another material than gypsum. The es- sentials of the inventive solution are that the holding members of the mounting rail, which holding members are described in the following, shall be capable of penetrating into the plate- shaped element when it is pressed into the groove of the mounting rail. Consequently, the inventive mounting rail is in- tended for mounting plate-shaped elements having a certain softness.

A mounting rail 2 for fastening a plate-shaped element, such as for instance a gypsum board 1, to a support surface 4 is illus- trated in cross-sectional view in fig 2-4. The mounting rail 2 comprises a groove 6 designed to receive an edge section 1a of the gypsum board. The groove 6 has two parallel or at least es- sentially parallel sidewalls 7a, 7b, which are intended to bear on either side of the gypsum board when the edge section 1 a thereof is inserted into the groove, as illustrated in fig 4. The distance between the two sidewalls 7a, 7b shall consequently essentially correspond to the thickness of the plate-shaped ele- ment that is to be inserted into the groove 6. The sidewalls 7a, 7b are joined to each other by a rib forming a bottom 9 of the groove 6. At least one of the sidewalls 7a, 7b of the groove is provided with holding members 10, which protrude from the as-

sociated sidewall 7a, 7b into the groove 6. These holding mem- bers 10 are intended to penetrate into the gypsum board 1 when it is pressed into the groove in a direction towards the bottom 9 of the groove. Owing to the holding members 10 being pressed into the gypsum board 1, they will obstruct the edge section 1a of the gypsum board inserted into the groove 6 from being drawn out of the groove 6 and they will consequently help to keep said edge section 1a, and thereby the gypsum board 1, se- cured to the mounting rail 2. Preferably, both sidewalls 7a, 7b of the groove 6 are provided with holding members 10 of the type in question. The holding members 10 are distributed along the length of the mounting rail, preferably with regular mutual inter- spaces, i. e. with regular interspaces between adjacent holding members.

The respective holding member 10 is suitably located somewhat above the bottom 9 of the groove so that there is a certain inter- space between the bottom 9 of the groove and the lower end of the holding member facing the bottom of the groove. This inter- space is suitably 5-10 mm at a mounting rail dimensioned for mounting single or double gypsum boards.

The mounting rail 2 is suitably fastened to a support surface 4 by means for fastening elements 11 in the form of screws, nails or the similar, as illustrated in fig 2-4. In the embodiment here illustrated, the bottom 9 of the groove is provided with through holes 12 intended for said fastening elements 11.

In the embodiment illustrated in fig 2-5, one sidewall 7a has a shorter extension perpendicular to the bottom 9 of the groove than the other sidewall 7b. The shorter sidewall 7a has a flange 13 at its end facing away from the bottom 9 of the groove, which flange is angled obliquely outwards from the sidewall 7a. The angle a between the flange 13 and an extension of the sidewall 7a is suitably between 10-90°, preferably between 30-45°. This

flange 13 is intended to facilitate the insertion of the edge sec- tion 1 a of the gypsum board into the groove 6.

A method for mounting a gypsum board 1 with the aid of a mounting rail 2 according to the invention is illustrated in fig-2-4.

The mounting rail 2 is at first fastened to the support surface 4.

If considered suitable, the mounting rail 2 may at first be fas- tened to the support surface with the aid of a stapler or the similar, whereupon the mounting rail 2 is secured to the support surface 4 by means of fastening elements in the form of for in- stance screws 11 through the holes 12 in the mounting rail 2.

Thereafter, an edge section 1a of the gypsum board 1 is placed along the groove 6 of the mounting rail. In order to facilitate the insertion of the edge section 1 a into the groove, the gypsum board 1 may at first be placed obliquely in relation to the side- walls 7a, 7b so that an edge 1b of the board rests against the longer sidewall 7b, whereas a lateral surface 1c of the board bears against the flange 13 of the shorter sidewall 7a, as illus- trated in fig 2. Thereafter, the board is turned in the direction of the arrow 14 from the position illustrated in fig 2 to a position where the other lateral surface 1d of the board will bear on the longer sidewall 7b. The latter position is illustrated in fig 3. From the position illustrated in fig 3, the edge section 1a of the board is then pressed into the groove 6 in the direction towards the bottom 9 of the groove. This displacement direction is in fig 3 illustrated with the arrow 15. The displacement of the gypsum board 1 into the groove 6 will consequently take place perpen- dicularly to the bottom 9 of the groove. When the edge section 1a has been pressed into the groove 6, the holding members 10 will penetrate into the gypsum board 1. Fig 4 illustrates the final position when the edge section 1a of the gypsum board is in- serted into the groove with the holding members 10 in engage- ment with the board and with the lateral surfaces 1c, 1d of the board bearing on the respective sidewall 7a, 7b of the groove 6.

Since the holding members 10 are intended to penetrate into the plate-shaped element, they should be relatively stiff so as not to bend away too much when the plate-shaped element is pressed into the groove 6. If so considered suitable, the holding mem- bers 10 may have a small flexibility so that they in addition to penetrating into the plate-shaped element also are bended somewhat when the plate-shaped element is pressed into the groove so that they produce a certain retaining clamping effect perpendicular to the lateral surfaces 1c, 1d of the plate-shaped element.

A section of the mounting rail according to fig 2-4 is illustrated in a perspective view in fig 5. In order to reinforce the fixing of the plate-shaped element to the mounting rail 2, the mounting rail is suitably provided with through holes 20 in at least one of the sidewalls 7a, 7b. Through these holes 20, the plate-shaped element 1 can be fixed to the mounting rail 2 by means of fas- tening elements, such as screws, nails or the similar. Further- more, the flange 13 is suitably provided with through holes 21 for fastening the mounting rail 2 to suspension members, such as hooks or the similar.

The respective holding member 10 preferably has a cutting edge 30, which is intended to cut into the plate-shaped element when an edge section thereof is pressed into the groove 6. The re- spective holding member 10 suitably consists of a cutting tooth, as illustrated in fig 2-5. The cutting tooth 10 is here angled obliquely outwards from the associated sidewall 7a, 7b in the direction towards the bottom 9 of the groove. The angle between the upper surface 32 of the cutting tooth and the associated sidewall 7a, 7b is suitably between 5-15°, preferably about 10°.

As seen in a projection against the associated sidewall 7a, 7b, the cutting tooth 10 illustrated in fig 5 is tapered in the direction towards the bottom 9 of the groove so that the lower end of the cutting tooth facing the bottom 9 of the groove forms a sharp tip 33. The upper surface 32 of the cutting tooth is consequently

tapered in the direction towards the bottom 9 of the groove and has the shape of a triangle. The respective cutting tooth 10 suitably has a length of 2-10 mm, preferably 3-5 mm. In case of a dimensioning for a single or double gypsum board, the re- spective cutting tooth suitably has a length of 3-5 mm.-» The length of the cutting tooth here refers to the distance from the upper to the lower end of the cutting tooth.

The respective holding member 10 is suitably integrated with the associated sidewall 7a, 7b and is preferably formed by punching of the associated sidewall 7a, 7b. The cutting teeth 10 illus- trated in fig 5 are formed by such punching and the thickness of the cutting teeth consequently corresponds to the thickness of the sidewall in this case. In the embodiment illustrated in fig 5, the lower end 35 of the cutting tooth facing the bottom 9 of the groove is free, whereas the cutting tooth 10 is connected to the associated sidewall 7a, 7b at its upper end 36 facing away from the bottom 9 of the groove. Hereby, a certain flexibility of the cutting tooth 10 is obtained at the same time as it is sufficiently stiff to efficiently cut into a gypsum board 1 or a similar plate- shaped element that is pressed into the groove 6.

Fig 6 illustrates a section of a mounting rail 3 of corner-type, which is intended to join two outer edge sections of two plate- shaped elements 1 arranged perpendicularly to each other, for instance as illustrated in fig 1. This mounting rail 3 is provided with a groove 6 for receiving an edge section of one of said plate-shaped elements. In one or both of the sidewalls 7a, 7b of this groove 6, fastening members 10 are arranged in the same manner as in the above-described mounting rail 2. The sidewall 7a intended to face the other of said plate-shaped elements has a flange 40 at its end facing away from the bottom 9 of the groove, which flange is angled perpendicularly to the sidewall 7a in a direction away from the groove 6. The mounting rail 3 is in- tended to be pressed against the outer edge section of one of the plate-shaped elements that are to be joined so that the

holding members 10 penetrate into this plate-shaped element. If so considered suitable, one or both of the sidewalls 7a, 7b may be provided with through holes in order to make possible an ad- ditional fixing of the plate-shaped element to the mounting rail 3 by means of fastening elements, such as screws, nails or the similar. The other of the plate-shaped elements that are to be joined by means of the mounting rail 3 is placed with its outer edge surface against the external side of the sidewall 7a and with one lateral surface bearing on the side of the flange 40.

The flange is suitably provided with through holes 41 in order to make possible a fixing of the other plate-shaped element to the mounting rail 3 by means of fastening elements, such as screws, nails or the similar.

A further embodiment of a mounting rail 3 of corner-type is il- lustrated in fig 7. The mounting rail 3 here comprises two grooves 6a, 6b for receiving an edge section of a respective plate-shaped element 1. In one or both of the sidewalls 7a, 7b of the respective groove 6a, 6b, fastening members 10 are ar- ranged in the same manner as in the above-described mounting rail 2. If so considered suitable, one or both of the sidewalls 7a, 7b of the respective groove 6a, 6b may be provided with through holes in order to make possible an additional fixing of the plate- shaped elements to the mounting rail 3 by means of fastening elements, such as screws, nails or the similar. In the embodi- ment illustrated in fig 7, one sidewall 7a of the respective groove has a shorter extension perpendicular to the bottom 9 of the groove than the other sidewall 7b. The shorter sidewall 7a has a flange 13 at its end facing away from the bottom 9 of the groove, which flange is angled obliquely outwards from the sidewall 7a. The angle a between the flange 13 and an exten- sion of the sidewall 7a is suitably between 10-90°, preferably between 30-45°. This flange 13 is intended to facilitate the in- sertion of the edge section of the gypsum board into the groove 6a, 6b. The mounting rail illustrated in fig 7 is suitably manu- factured by two identical rails 2a, 2b, which are joined to each

other at a right angle by means of suitable fastening elements, welding, gluing etc, one rail 2a being placed with the external side of the bottom of the groove bearing on the external side of one sidewall 7a of the other rail 2b. In the embodiment illus- trated in fig 7, the mounting rail 3 is manufactured by two-raits 2a, 2b of the type illustrated in fig 5.

In the embodiment illustrated in fig 7, both of the grooves 6a, 6b of the mounting rail are arranged perpendicularly to each other in order to make possible a joining of two plate-shaped elements at a right angle in relation to each other. However, the grooves may of course be angled in another manner in relation to each other for joining two plate-shaped elements at a desired angle in relation to each other. The corresponding also applies to, the angle of the flange 40 in relation to the associated sidewall 7a of the mounting rail 3 illustrated in fig 6.

The mounting rail 2,3 may for instance have a length of about 2,5 m with an interspace of about 100 mm between adjacent holding members 10 in the longitudinal direction of the mounting rail. In case of a dimensioning for a single gypsum board, the groove 6 suitably has a width of about 13 mm, in which case the shorter sidewall 7a suitably has a height of about 13 mm and the longer sidewall 7b a height of about 28 mm.

The mounting rail 2,3 is suitably manufactured of steel-sheet, preferably galvanized steel-sheet, but may also be manufac- tured of other materials, such as for instance aluminium sheet.

The thickness of the utilised sheet is suitably about 0,5 mm.

The mounting of the unit illustrated in fig 1 is carried out ac- cording to the following. A first mounting rail 2 is fastened to the first support surface 4a and a second mounting rail 2 is fastened to the second support surface 4b, which is arranged at an angle in relation to the first support surface. In fig 1, said support surfaces 4a, 4b are perpendicular to each other. An edge sec-

tion of a first plate-shaped element is then inserted into the groove of the first mounting rail and an edge section of a second plate-shaped element is inserted into the groove of the second mounting rail in the above-described manner so that the outer edges of the two plate-shaped elements meet at an angte to each other, whereupon the two plate-shaped elements are joined at their outer edges by means of a third mounting rail 3 of corner-type. After the mounting of the plate-shaped elements, any desired finishing treatment may be performed, the formed unit for instance being putted, painted etc.

The invention is of course not in any way limited to the preferred embodiments described above, on the contrary several possi- bilities to modifications thereof should be apparent to a person skilled in the art without departing from the basic idea of the in- vention as defined in the appended claims. The mounting rail 2 may for instance be modified for mounting a plate-shaped ele- ment at another angle than a right angle in relation to a support surface.