The invention relates to a rail arrangement, and more specifically it relates to a rail arrangement that is fixed to a building or building structure, and is adapted to be able to support, displaceably along a rail belonging to the rail arrangement, a load connected to a beam, for example a platform, suspended scaffolding or hoisting apparatus with hoisting cage or the like, which is vertically movable up and down along a wall portion of a building, and which can be displaced sideways.

Such rail arrangements are known and as an example of the closest prior art known to the applicant, reference is made to his Norwegian patent, No. 311422.

This document describes a rail arrangement wherein a supporting beam comprises a first beam portion and a second beam portion, and the second beam portion is via running rollers able to cooperate with a rail fixed to the building, the second beam portion being arranged for cooperation with a hollow or cavity-profiled rail, and wherein the second beam portion is provided with a plurality of force-absorbing running rollers, wherein at least a first running roller is oriented to act against a first rail portion with a rolling face facing away from the first beam portion, and at least a second running roller is oriented to act against a second rail portion and against a rolling face on the rail portion facing towards the first beam portion, and at least a third running roller is oriented to act against a third rail portion and against a rolling face on the rail portion that is oriented horizontally or substantially horizontally, and the first and the third running roller and the rolling faces cooperating with them are enclosed in an open cavity in the rail.

The known rail arrangement is designed for horizontal, or substantially horizontal, displacement of the beam bearing the hoisting arrangement/hoisting basket, and for this purpose it functions as intended. The patent does not describe the use of drive rollers or drive wheels to provide the horizontal displacement. If such rollers or wheels were to be used, the rolling friction between the drive wheels and the rolling face would be insufficient to ensure propulsion and braking in planes that deviate from a substantially horizontal plane.

However, there has arisen a need for a rail arrangement of the type in question which can also be used for displacement/propulsion and braking/securing of the beam etc. in an inclined plane relative to the horizontal plane. Rail arrangements that can provide such movement are per se also known; see, for example, Norwegian Patent No. 156406 and Swedish Patent No. 466 480, which are owned by the applicant. However, the arrangement in these documents requires the drive wheels that provide the movement to encircle the rail and be clamped against it, i.e., that the clamping forces act diametrically against each other, in order to obtain the necessary frictional force. To provide this arrangement, the rail must arranged at a distance from the surface on which it is to be mounted.

The arrangement is highly suitable for the transport of goods, articles and the like, where the rail installation is of no importance as regards appearance when it is not in use. However, it is not suitable for use in rail arrangements of the type mentioned in the introduction, where it is desirable that the rail arrangement should be as least visible as possible.

It is therefore desirable that the rail arrangement should be mounted inside the wall and arranged in such manner that it does not form a marked, noticeable change to the face of the wall.

The object of the invention is to remedy the aforementioned deficiencies of the prior art, and this is achieved with an arrangement of the type mentioned above which is characterised by the features in independent claim 1.

Advantageous embodiments of the invention are disclosed in the dependent patent claims.

The invention will now be described with reference to the drawings, wherein:

Fig. 1 is a schematic side view in partial section of a first embodiment of the invention and elements that may be components thereof;

Fig. 2 is a perspective view of a trolley unit or crab with a supporting beam mounted thereon;

Fig. 3 is a schematic side view of the crab in Fig. 2;

Fig. 4 is a schematic sectional side view, on a larger scale, of the profiled rail with crab in a first embodiment; Figs. 5 and 6 show the same as in Fig. 4 in a second and third embodiment;

Fig. 7 shows the same as Fig. 4 modified with an auxiliary chain drive;

Fig. 8 shows the same as in Fig. 4, but where the drive wheel has been modified to increase friction against the rolling face by means of integral rack-and pinion drive;

Figs. 9-12 are schematic illustrations of other embodiments of the rail profile, drive wheels and running wheels;

Fig. 13 is a schematic illustration of a skewed rail profile with a horizontal arm;

Fig. 14 is a schematic illustration of a horizontal rail portion with a tilted arm; and

Fig. 15 is a schematic illustration of a rail profile with an arm in a bend around a corner.

In the figures like reference numerals are used to refer to like or corresponding parts.

Fig. 1 is, as mentioned, a schematic side view in partial section of a first embodiment of the invention and elements that may be components thereof.

In the drawing the arrow with reference numeral 1 indicates the rail arrangement according to the invention. This arrangement comprises a profiled rail 2 which is preferably arranged inside an enclosure 12. The rail arrangement 1 is provided with holes, mounting edge, slotted grooves or similar means for ensuring attachment to a building structure. The arrangement 1 further comprises a beam 3 or another suitable suspension means. At the free end portion of the beam 3 there is indicated a suspension device 10 for suspension of a load such as a platform, suspended scaffolding or hoisting apparatus with hoisting basket or the like. The load as such does not relate to the invention, but it may be a load of from some tens to several hundreds of kilos or more, and the arrangement must of course be dimensioned to bear the load in question. Provided at the opposite end portion of the beam is a trolley unit or a so-called crab 5 consisting of a central plate, on opposite sides of which there are rotatably arranged one or more drive wheels 6 and running or support wheels 7, respectively. A pair of wheels on each side is shown in Figures 2 and 3. Displacement of the crab 5 can take place either manually or with the aid of one or more drive motors. A drive motor 4 that is equipped with suitable transmissions for operation of the drive wheel or drive wheels 6 is indicated in Fig.l. The motor 4 may be any suitable motor, and it may, for instance, be an electric motor or a hydraulic motor. The power supply to the motor 4 can be provided by means of an electric cable or hydraulic lines (not shown), or a conductor rail arrangement 11 can be installed as indicated in Fig. 1. The trolley unit 5 may be detachably fastened to the beam 3 by suitable fastening devices such as screw bolts or the like, or it may be fixedly mounted to the beam 3, for example, welded thereto or in another way provided as an integral part of the beam. The profiled rail 2 is formed having an intermediate web portion which at opposite ends is formed having outwardly projecting legs that are provided with respective rolling faces 8a and 8b. Drive wheel 6 and running or support wheel 7 are also provided with respective rolling faces 9a and 9b, and the crab 5 is arranged inside the profiled rail 2 in such manner that the rolling faces 8a and 8b on the rail 2 rest against the rolling faces 9a and 9b on the drive and support wheels 6 and 7 respectively, as can be seen for example in Fig. 4.

Different designs of the cooperating rolling or contact faces are shown in the figures. For the arrangement 1 to function in a satisfactory manner when mounted in a plane that slants relative to the vertical plane, it is essential that the drive wheel or wheels 6 obtain sufficient factional force against the flat contact or rolling face of the rail portion. To achieve this, the cooperating contact portions on respectively the rail 2 and the drive wheel 6 are provided with a small angular difference so that something close to point contact is achieved, i.e., a contact point with very limited area, and thus greater friction. The moment that is transferred from the load via the beam 3 to the drive wheels 6 on the crab 5 and thence to the contact faces 8a and 8b on the rail 2, which are so oriented that the friction which arises when the profiled contact faces "nip" against each other, so that propulsion along the axis of the rail 2 is allowed also when the rail has a gradient.

To ensure auxiliary power for enhanced climbing ability, further drive devices may be provided as indicated schematically in Figures 7 and 8, where the reference numerals 13 and 14 in Fig. 7 indicate an integral chain drive arrangement which can be operated by means of suitable drive couplings connected to the drive wheel 6 or the drive motor 4, and the reference numeral 15 in Fig. 8 indicates that "teeth" or the like may be provided in a bottom portion of the drive wheel 6 and, for example, cooperate with corresponding grooves in the rail 2 (rack and pinion drive). The operation of the additional drive devices may optionally be provided by suitable additional drive motors with necessary couplings/transmissions. With regard to the support wheels 7, it is desirable that these should only be exposed to normal rolling friction and the angling of cooperating faces should be as complementary and uniform as possible.

The positioning, orientation and dimensioning of the faces or the profile form against which the wheels 6 and 7 rest can be varied and moved on the surface of the rail 2 as long as the forces/moment from the load are taken up by the rail 2 as a torsional moment. Both drive wheels 6 and support wheels 7 may have a concave or convex form as indicated in Figs. 5 and 6. Here, however, the surface of the drive wheels 6 should be made having a different radius than the corresponding rolling face on the rail, thereby ensuring that the desired small contact area is obtained. The support wheels may also be formed as a roller of cylindrical form as indicated in Figures 10-12. The horizontal distance between the rolling faces of the upper and lower drive and support wheels 6 and 7 may be zero or almost zero, as indicated in Fig. 9, or be offset depending on the need for load-bearing capacity, as is shown in the other figures.

The trolley unit or crab 5 may be articulated so that it 5 can be run through horizontal or vertical curves in the rail 2. At least one of the wheels 6 and 7 can be split at the centre of the shaft and pressed together by a spring bank in order to take up irregularities and any other operating disturbances, and to be able to maintain a good grip also in curvatures in the rail arrangement. Furthermore, the trolley unit 5 can be equipped or provided with a suitable safety means (not shown) which locks the trolley unit inside the rail profile if one or more shafts are damaged or snap.

When passing, for example, a house corner, the rail 2 will inevitably have a greater distance from the facade surfaces than on a straight stretch of rail. However, the applicant has found that this problem can be solved by arranging the beam 3 that projects out from the wall at a suitable angle to the rail 2. In the bend around the corner, the rail is also skewed at a suitable angle so that when the beam 3 passes around the house corner, it points straight out and extends so as to provide a suitable distance between the house corner and the suspension means 10.

If the beam 3 or arm has been arranged at a suitable angle relative to the plane of the rail 2, as illustrated in Fig. 14, the beam 3 can be made to project substantially horizontally, as illustrated in Fig. 13, by turning the rail 2 through a suitable angle. Thus by arranging the rail 2 so that it is skewed in the bend area whilst the beam 3 is arranged at an angle relative to the rail, it is ensured that the beam 3 projects out a suitable distance from the facade surfaces in the bend around the house corner, as illustrated schematically in Fig. 15.

As an example of a specific embodiment of a bend arrangement, a beam or arm that is 700 mm may be envisaged. If the arm is angled at an angle of about 60 degrees, this will mean, on a straight length of rail, that the arm in practice extends the necessary 500 mm out from the facade surface. When there is a bend, this distance will be substantially reduced. By having an inclined arm and a rail section skewed at a suitable angle in the bend, it is ensured that the arm "lies" horizontally and thus extends about 200 mm further out. This means that it is possible to move around corners without unhooking the working platform.

In summary, it may be stated that the rail arrangement 1 according to the invention is designed and functions in such manner that the rail 2 encircles the trolley unit or crab 5 equipped with one or more drive and supporting wheels, 6 and 7 respectively, having contact or rolling faces, 9a and 9b respectively, which encircle internal, matchingly profiled contact or rolling faces, 8a and 8b respectively, at the bottom and top of the rail 2 in such manner that the moment from a load on an arm or beam 3 projecting from a longitudinal slot in the rail 2 is transferred to internal faces in the rail 2 that is fixed to the building structure, which arrangement is provided for motorised operation and comprises at least one drive/braking wheel 6 with good gripping power in the contact face or faces 8.

When the arrangement 1 is not in use, the beam 3 with optional motor 4, and possibly also the crab 5, can be dismantled. A sealing element in the form of a lipped part, cover or the like can be placed over the enclosure opening.

Although the invention has been described above by means of an exemplary embodiment, it is clear that it is not limited to this embodiment, but the scope is disclosed in the patent claim below.