DESCRIPTION

The present invention relates to a system and a method for the application of plaster on a surface, in particular on a wall.

In particular, the system and the method according to the invention have advantageous use both in the application of plaster on traditional walls and on walls made with disposable formworks.

As will appear clear from the following description, the system according to the present invention is, in part, disposable.

Currently, to obtain a uniform and planar plastered surface, operators must first identify, through a plumb bob, the highest level, i.e. the most protruding of a vertical wall, of the rough wall and the lowest, i.e. the least protruding.

At this point, starting from the lowest level, the operator starts to create a series of vertical stripes of mortar on the rough wall, normally about 10 cm wide and 1 cm thick and separated from one another by about 100-150 cm, which act as reference lines for the subsequent application of plaster.

The creation of such vertical stripes normally takes place through continuous level measurements, and by adding and removing the mortar to bring all the stripes of cement mortar to the same level.

From the above, it can clearly be understood how, for the related performance, the above described operations are very time consuming and also require the use of a team of at least two or three specialist operators.

Once the aforementioned vertical reference stripes have been performed, metal profiles are applied at the top thereof which are aligned with the plumb bob.

After this operation, it is necessary to wait for the mortar stripes thus obtained to dry before filling the areas of wall comprised between the various stripes with more mortar, which is normally applied using a trowel or using mechanical means, for example pumps.

At this point, it is possible to proceed to level the mortar applied on the wall and to eliminate the excess part, by resting a strike-off rod on two adjacent stripes and making it slide upwards with oscillating movements to the right and left, and proceeding to perform the subsequent finishing with a float.

After the plaster has dried, the metal bars are removed, while the empty spaces left by them in the vertical stripes are filled with more plaster.

Subsequently, the entire surface is skimmed in order to obtain a uniform surface.

Once the operations described above have been implemented, it is finally possible to proceed to paint the wall thus obtained.

An example of a solution of the known type is described in patent US 4115976 A, which relates to an apparatus and method for screeding floors with cement.

An object of the present invention is to solve the problems of the known art identified above.

Another object of the invention is to provide a method for the application of plaster on a surface, with lower implementation times.

A further object of the invention is to provide a method for the application of plaster on a surface, which is easily implementable even by not specifically trained personnel. Another object of the present invention is to provide a method for the application of plaster on a surface, which allows labour costs to be significantly reduced with respect to traditional methods.

Another object of the invention is to provide a system for the application of plaster on a surface, which is cheap and easy to implement.

Therefore, the specific subject matter of the present invention is a system for the application of plaster on a surface, said system comprising at least one group comprising: support means fixable to said surface; a plurality of screws which can be screwed into said support means, each screw of said plurality of screws being provided with a head wherein a seat is formed; a plurality of alignment members , wherein each alignment member of said plurality of alignment members is provided with an engagement portion configured to engage rotatably in said seat; in each alignment member of said plurality of alignment members there being formed a groove; and a level bar configured in such a way as to be able to be coupled with said groove, so that when said plurality of screws is screwed into said support means fixed, in use, to said surface and said plurality of screws, said plurality of alignment members and said level bar are mutually coupled by inserting said engagement portion in said seat and said level bar in said groove, said level bar being vertically positionable, i.e. plumb, by adjusting the screwing of said plurality of screws, so as to provide a rest for levelling, in use, a determined quantity of material for plaster arranged on said surface.

Moreover, according to the invention, said support means may comprise a support bar fixable to said surface, in said support bar there being formed a plurality of holes configured for receiving said plurality of screws. Alternatively, according to the invention, said support means may comprise a spacer element suitable for being integrated, in use, into a disposable formwork for the construction of a wall.

Preferably, according to the invention, said engagement portion may comprise a pin having substantially the shape of a cylinder with an enlarged portion defined in a circumferential region of said cylinder.

Advantageously, according to the invention, said seat may have a shape complementary to said pin.

Again according to the invention, said level bar may comprise a protruding portion that extends longitudinally with respect to said level bar; in an intermediate zone of said protruding portion there being defined an enlarged portion.

Furthermore, according to the invention, said groove may have a cross section of a shape substantially complementary to a cross section of said protruding portion.

Preferably, according to the invention, said level bar may have a substantially T-shaped cross section.

Advantageously, according to the invention, a substantially flat external surface is formed in said level bar.

Further subject matter of the present invention is a method for the application of plaster on a surface through a system of the type indicated above, said method being characterised in that it comprises the steps of: screwing said plurality of screws into said support means integral with said surface; coupling said plurality of alignment members to said plurality of screws by inserting each engagement portion into the seat of the head of a screw of said plurality of screws; coupling said level bar to said plurality of alignment members by inserting at least one portion of said level bar into said groove; bringing said level bar to a vertical position, i.e. plumb, by adjusting the screwing of said plurality of screws; applying a given amount of plaster to said surface; and sliding a bar over said level bar in such a way as to level off said given amount of plaster.

Characteristics and advantages will become more apparent in the following description of preferred but not exclusive embodiments shown by way of non- limiting example in the appended drawings, wherein:

figure 1 is an exploded view of a system for the application of plaster on a surface, according to a further embodiment of the present invention;

figure 2 is an exploded view of a system for the application of plaster on a surface, in a second embodiment of the invention;

figure 3 is a larger scale view of a component of the systems shown in figures 1 and 2;

figure 4 is a partial view, in a larger scale, of another component of the systems represented in figures 1 and 2; and

figure 5 is a partial view, in a larger scale, of the components according to figures 3 and 4; mutually coupled.

With reference to the appended figures, 1 indicates a group of a system for the application of plaster on a surface, in which a plurality of groups 1 is provided.

In particular, such group 1 comprises a support bar 2 in which a plurality of seats 3 is afforded and arranged at a predetermined distance from one another.

The group 1 further provides a plurality of self-tapping screws 4 of the same number as that of the seats 3 and configured to be engaged, by screwing, into said seats 3. In the head 5 of each self-tapping screw 4 a cavity 6 is afforded, which reproduces in negative the shape of a cylinder with a central enlarged portion 6a.

The group 1 also comprises a plurality of inserts 7, also of the same number as the seats 3 in the support bar 2 and the self-tapping screws 4.

Each insert 7 has a main body 8 of a substantially parallelepiped shape.

From a first face of such main body 8 a pin 9 projects having a shape complementary to that of the cavity 6 of each self-tapping screw 4, and therefore substantially the shape of a cylinder with an enlarged portion 9a identified in a respective intermediate circumferential region, so that said pin 9 can be engaged by pressing the self-tapping screw 4 into the cavity 6, creating a shape coupling and hence being able to rotate freely about itself.

On a second face of the main body 8, opposite said first face, there is a rectilinear groove 10 substantially having a U-shaped profile with a slight enlargement 10a in a respective intermediate zone.

The group 1 also provides a level bar 11 substantially having a T shape and formed, in particular, by a flat portion 12 from whose central zone, an engagement portion 13 projects, along the entire longitudinal extension thereof, having a complementary profile to that of the groove 10 of each insert 7, i.e. with an enlarged portion 13a defined in a respective mtermediate zone, so that said engagement portion 13 can be engaged by pressing into the various grooves 10.

For the use of the aforementioned system for the application of plaster on a surface, it is necessary in the first place to provide for the anchoring of a first group 1 through fixing the related support bar 2 onto a rough wall, for example through the application of resins, Fischer plugs, or through an adhesive provided on the rear part of the support bar 2 itself.

In particular, the support bar 2 is applied to the rough wall with the related seats 3 facing outwards.

Once the support bar 2 has been fixed to the wall, the self-tapping screws 4 are completely screwed until they abut into the relevant seats 3 provided on the support bar 2, and the pins 9 of the inserts 7 are inserted into the cavities 6 of the self-tapping screws 4.

After adjusting the rotation of the inserts 7 so that the relative grooves 10 are all aligned vertically, the engagement portion 13 of the level bar 11 is inserted into the groove 10 of each plug 7.

At this point, further groups 1, parallel and spaced out from one another, are fixed to the wall, following for each of them the operations described above with reference to the first group 1.

Once the various groups 1 provided have been fixed to the wall, the level bars 11 of all the groups 1 are brought to the same level by unscrewing the individual self- tapping screws 4 by the amount necessary so that the external surfaces of the respective flat portions 12 all fall onto the same imaginary plane arranged plumb, taking as a reference point the most projecting self-tapping screw 4, i.e. the one having the highest level with respect to the vertical of the wall.

Once the operations for fixing the various groups 1 that comprise the aforementioned system and the levelling operations of the respective level bars 11 have been completed, it is possible to proceed with the application of plaster onto the wall and the related smoothing process through the traditional technique described in the introduction to the present description, i.e. by sliding a strike-off rod vertically on two or more level bars 11.

After the plaster has dried, the level bars 11 must be removed and the empty spaces to be left in the wall are filled with more plaster, then the plaster used for filling is smoothed in order to obtain a completely uniform surface.

At this point, the wall is ready for the related skimming and subsequent painting.

Now with reference to figure 2, Γ indicates a group of a further system according to the present invention, for the application of plaster on a surface, in which a plurality of groups is provided.

The system comprising groups Γ is conveniently suitable to be used in the application of plaster on walls made of disposable formworks formed by opposing panels mutually joined by spacer members, such as the one shown in figure 2 and indicated with reference number 14'.

Each group comprises a plurality of self-tapping screws 4', a corresponding plurality of plugs 7' and also a level bar 11', respectively the same as the self-tapping screws 4, the plugs 7 arid the level bar 11 described above with reference to the group 1.

However, in this case, the self-tapping screws 4' are screwed into the corresponding holes 15' provided in the aforementioned formworks, preferably on the external sides of the same spacer members 14'.

In this system, therefore, the spacer member 14' is part of the group 1', acting as a support element for the self -tapping screws 4'.

Once the self-tapping screws 4' have been screwed into the holes 15', the same operations described above with reference to the groups 1 of the first system according to the invention are performed.

According to a further embodiment of the present invention, not shown in the appended figures, instead of the support bar 2 and the self-tapping screws 4 described above, a series of hexagonal head screws, i.e. screws that as well as the element with a male thread also comprise a support for such element with a male thread, can be used.

In the latter case, such supports are fixed into the wall to be plastered, using a bar with a template function in order to preliminarily define their position on the wall so as to be vertically aligned.

Both systems described above, respectively comprising groups 1 and groups 1\ therefore allow the total plastering times for the walls to be drastically reduced, overcoming the traditional method of identifying the so-called "guides" so as to obtain an important site economy, to substantially reduce labour costs and the time scales for creating masonry plaster.

Furthermore, the systems according to the invention are not subject to a sequence of levelling attempts, which are envisaged in the traditional teclmiques and inevitably connected with the skill of the individual specialist operator; the use of such systems is rather entrusted to a site technology which can be easily used by any operator.

The above is intended to provide an exemplificative and non-limitative description, therefore any construction variations are considered to fall within the scope of protection of the present technical solution as described above.