INVENTION DESCRIPTION

1. FIELD OF APPLICATION

The invention relates to a stair leveling device by which concrete stairs are leveled before the finishing work.

In the International Patent Classification, it is classified as Section E - Fixed constructions; E04 - Building; E04F - Finishing work on buildings, e.g. stairs, floors; E04F 1 1/09 - Tread- and-riser units, and 1 1/1 16 - of concrete; or E04F 21/26 - Tools for marking steps.

2. TECHNICAL PROBLEM

Once a concrete stairway is constructed, the stairs have to be leveled. Leveling work is performed by applying a layer of material so that all stairs get the same height and depth and become horizontal and mutually parallel. Thus worked stairs can be considered as they are completely finished, or they can make base for finishing work by covering the stairs with some tile elements.

Stair leveling is a complicated job which is in practice usually improvised in a way that stair tread is worked separately from stair riser. Therefore, this operation has to be paid particular attention in order to, at the end, produce quality stairs.

The technical problem that is solved by this invention relates to construction of a device to be used for leveling work of stair risers and treads simultaneously, before finishing work of the stairs by covering them with some tile elements.

3. STATE OF THE ART

No similar devices for leveling stairs are known to exist. In practice, stairs are leveled by partial improvisations, where leveling work of the treads is performed separately from leveling work of the risers. Leveling is usually performed by complicated improvisations or by repeated formwork as in the first step of concreting. 4. ESSENCE OF THE INVENTION

The essence of the invention is the stair leveling device.

The stair leveling device is intended primarily for leveling concrete stairways.

Leveling of the stairs relates to applying of semi-dry concrete screed simultaneously onto the stair treads and risers, in order to get horizontal and parallel surfaces, as well as uniform heights and depths of the stairs.

The stair leveling device comprises: main bar assembly, left base assembly, right base assembly, bar extension, sliding holder assembly and lateral bar assembly.

The main bar assembly is movably connected with the left base assembly and the right base assembly. The left and right base assemblies enable adjusting of height, depth and inclination of the main bar assembly relative to the tread and the riser of the stair that is being leveled.

5. BRIEF DESCRIPTION OF DRAWINGS

Figure 1 shows the stair leveling device - front view.

Figure 2 shows the device shown in the Fig.1 - top view.

Figure 3 shows the device shown in the Fig.1 - left side lateral view.

Figure 4 shows the main bar assembly - front view.

Figure 5 shows the assembly shown in the Fig.4 - top view.

Figure 6 shows the assembly shown in the Fig.4 - side view.

Figure 7 shows the bar extension - front view.

Figure 8 shows the bar extension - left side lateral view.

Figure 9 shows the sliding holder assembly - front view.

Figure 10 shows the sliding holder assembly - top view.

Figure 1 1 shows the clamp holder - front view.

Figure 12 shows the clamp holder - lateral view.

Figure 13 shows the left base assembly - front view.

Figure 14 shows the left base assembly - left side lateral view.

Figure 15 shows the left base assembly - top view.

Figure 16 shows the right base assembly - front view.

Figure 17 shows the right base assembly - right side lateral view. Figure 18 shows the right base assembly - top view.

Figure 19 shows the base - front view.

Figure 20 shows the base - top view.

Figure 21 shows holder of the main bar assembly - front view.

Figure 22 shows the holder shown in the Fig.21 - left side lateral view.

Figure 23 shows the holder shown in the Fig.21 - top view.

Figure 24 shows the lateral bar - front view.

Figure 25 shows the lateral bar - left side lateral view.

Figure 26 shows the lateral bar - top view.

6. DETAILED DESCRIPTION OF THE INVENTION EMBODIMENT AND FUNCTIONING

The stair leveling device is intended primarily for leveling concrete stairways. Before starting leveling work of an existing concrete stairway, it is necessary to construct and draw on the lateral wall the exact heights of all risers and depths of all treads.

This operation shows exactly how much material is to be applied on each stair tread and riser. Leveling of concrete stairs relates to applying of semi-dry concrete screed, or another material, in order to level the treads and the risers simultaneously. Thus worked stairs can be considered as completely finished, or can make base for covering the concrete stairs with tile elements. The final aim is to construct stairs with horizontal and parallel surfaces, and with all risers of the same height and all treads of the same depth. This is achieved with the stair leveling device.

The stair leveling device enables simple and simultaneous preparation of all concrete stair treads and risers for leveling.

The stair leveling device A, Fig.1 , 2 and 3, comprises:

- main bar assembly B,

- left base assembly C,

- right base assembly D.

Main bar assembly B, Fig.4, 5 and 6, comprises: main bar 1 , bar extension 4, sliding holder 7, clamp holder 10, lateral bar 1 1 and clamp 12.

The main bar 1 is in shape of a profile with inner longitudinal hollows 2 and outer longitudinal canal 3. The inner longitudinal hollows 2 are intended to receive bar extensions and sliding holder arms fixing the bar extension to the main bar. In the outer longitudinal canal 3 are inserted holders of the left base assembly C and the right base assembly D. The bar extension 4 has at one end inserts 5 for mounting to the main bar 1 , and at the other end inner hollows 6 for connecting to the sliding holder 7, which holder has arms 8 and inserts 9. The clamp holders 10 are for tightening the sliding holder 7 to the main bar 1. The lateral bar 1 1 is placed on the main bar 1 or on the bar extension 4. The lateral bar 1 1 is used for leveling ends of stairs that are by one side fixed to the lateral wall, and the other side of the stairs is free. The bar extension 4, Fig.7 and 8, is for extending the length of the main bar 1 assembly, by inserting the bar extension inserts 5 into the longitudinal hollows 2 in the main bar 1. Into the longitudinal hollows 6, in the bar extension 4, are inserted inserts 9 of the sliding holder 7.

The sliding holder 7, Fig.9 and 10, comprises the arms 8 and the inserts 9. The sliding holder 7 is used when the main bar assembly B is extended with the bar extensions 4, where the arms 8 enter into the longitudinal lateral hollows 2 in the main bar 1 , and the inserts 9 enter into the hollows 6 in the bar extension 4. After that, the sliding holder 7 is fixed to the main bar assembly B with the clamp 12.

The clamp holders 10, Fig.1 1 and 12, are tube shaped, and are used to tighten the arms 8 of the sliding holder 7 to the main bar 1 .

The lateral bar 1 1 , Fig.24, 25 and 26, is used for leveling ends of stairs that are by one side fixed to the lateral wall, and the other side of the stairs is free. The lateral bar 1 1 is fitted over the bar extension 4 and the arms 8 of the sliding holder 7, and then it is fixed with the clamp 12.

The stair leveling device A is also provided with a spirit-level L, built into the main bar assembly B. The spirit-level L shows whether the main bar assembly is positioned horizontal and vertical relative to the base before leveling the stairs.

Left base assembly C, Fig.13, 14 and 15, and right base assembly D, Fig.16, 17 and 18, are constructed in the same way, the only difference is that their bases 20 and bars 24 are turned to face each other when the left base assembly C and the right base assembly D are mounted to the main bar assembly B.

The left base assembly C and the right base assembly D have frame that is constructed in the same way of square tubes and tubes with canals in which slide the square tubes. The left and right base assembly frames comprise: front vertical tube 13, back vertical tube 14, upper horizontal tube 15, lower horizontal tube 16, upper horizontal tube slider 17, lower horizontal tube slider 18, hinges 19, bases 20, supports 21 , holder 22 of the main bar assembly B with slider 23 and bar 24, and clamps 12.

The front vertical tube 13 is at the upper and the lower side of the frame movably connected, by the hinge 19, to the upper horizontal tube 15 and the lower horizontal tube 16. The lower horizontal tube 16 is at the back side of the frame firmly fixed to the back vertical tube 14 and slides in the slider of the lower horizontal tube 16. The upper horizontal tube 15 slides in the slider 17 of the upper horizontal tube. On the front vertical tube 13 there is fitted the slider 23 of the holder 22 of the main bar assembly B. At the lower end of the frame there is mounted the base 20 into which are screwed three supports 21 with spikes, distributed on the base 20 in a way they make a triangle, which always ensures the left and the right base assemblies secured and stable horizontal position on the stair tread, regardless of any possible uneven spots or roughness. The bases 20 are firmly fixed to the slider 18 of the lower horizontal tube in which slides the lower horizontal tube 16 of the frame.

The Fig. , 2 and 3 show example of an assembled stair leveling device A, comprising main bar assembly B, left base assembly C and right base assembly D.

The presented assembled stair leveling device A is used to level stairs that are by their left side fixed to the lateral wall, and their right side is free. Because of the greater width of the stairs, to the left and the right side of the main bar assembly B there are fitted the bar extensions 4. On the right bar extension there is fitted the lateral bar 1 1 for leveling of the stair right side ends.

The left base assembly C and the right base assembly D carry the main bar assembly B. For this purpose, the bars 24, of the holder 22 of the left and the right bar assemblies C and D, are inserted into the longitudinal canal 3 of the main bar 1 and after being adjusted, they are tightened with the clamps 12. Into the bases 20, at the lower ends of the left and the right base assemblies C and D, are screwed three supports 21 with spikes, distributed on the base 20 in shape of a triangle, so they always ensure the left and the right base assemblies secured and stable horizontal position on the stair tread, regardless of any possible uneven spots or roughness.

The main bar assembly B is, by means of the left and the right base assemblies C and D, simply adjusted by height, depth and inclination relative to the tread and the riser of the stair that is being leveled. Adjustment is performed according to the previously drawn stairs on the lateral wall. The left and the right base assemblies C and D, after bringing to their working position, are additionally pressed over the bases 20 against the stair tread. This pressure is exercised in any of the known ways. It suffices that the left and the right base assemblies are positioned only roughly against the stair riser, because further adjustments are performed by simply moving vertical and horizontal tubes of the left and the right base assemblies frames, and by fixing such adjusted position by means of the clamps 12. This enables great flexibility in adjusting the main bar assembly B relative to the stair that is being leveled.

The left and the right base assemblies C and D enable quick adjustment and removing the device from the stair once leveling is completed.

All movable assemblies and parts of the stair leveling device A are connected mutually with the clamps 12.

Leveling procedure:

Once the stair leveling device A is fixed to the uppermost stair tread, the main bar assembly B is being positioned horizontally and vertically by means of the left and the right base assemblies C and D, and the spirit-level L. In doing this, the main bar assembly B is to be detached by a few centimeters in front of the upper stair riser and above the tread of the stair that is being leveled.

In the space created between the main bar assembly B and the stair riser, and on the stair tread there is poured semi-dry concrete screed (mixture of sand and cement in ratio of 4: 1 ).

When the applied semi-dry concrete screed layer on the stair is compacted enough, the left and the right base assemblies C and D are released of the pressure against the bases and the entire leveling device A is moved to the next lower concrete stair tread. The above described procedure with the stair leveling device A is repeated on all stairs of the treated concrete stairway.

The stair leveling device A, according to this invention, significantly saves time of leveling the stairs, producing high quality stairs as bases for the finishing work by covering the stairs with tile elements. REFERRAL LETTERS AND NUMBERS IN DESCRIPTION AND DRAWINGS MEAN: A - stair leveling device

B - main bar assembly

1 - main bar

2 - longitudinal hollows

3 - longitudinal canal

4 - bar extension

5 - inserts

6 - hollows

7 - sliding holder

8 - arms

9 - inserts

10 - clamp holder

1 1 - lateral bar

12 - clamp

L - spirit-level

C - left base assembly

D - right base assembly

13 - front vertical tube

14 - back vertical tube

15 - upper horizontal tube

16 - lower horizontal tube

17 - upper horizontal tube slider

18 - lower horizontal tube slider

19 - hinges

20 - bases

21 - support with spike

22 - main bar assembly holder

23 - slider

24 - bar

12 - clamp 7. INVENTION APPLICATION

The stair leveling device, according to this invention, is mostly used for leveling concrete stairs by simultaneous leveling of stair treads and risers. The results are the stairs of horizontal and mutually parallel surfaces and uniform riser heights and tread depths. Leveling of the concrete stairs relates to applying onto the stairs of semi-dry concrete screed or another material. Such leveled stairs may be considered as they are completely finished or they can make base for laying onto them some tile elements.

Operating the stair leveling device is simple and adapted to the workers of various craft profiles.