WO2015011734A1

WO2015011734A1 - A plug element for the realization of a longitudinal cavity provided with traces in a reinforced concrete pillar and relative machinery

Info

Publication number: WO2015011734A1
Application number: PCT/IT2013/000203
Authority: WO
Inventors: Lapo Borghi
Original assignee: Lapo Borghi
Priority date: 2013-07-22
Filing date: 2013-07-22
Publication date: 2015-01-29

Abstract

The present invention concerns a plug element (50) for the formation of a cavity in a pillar. In accordance with the invention, the plug element is covered externally, at least in part, by a covering (65) comprising one or more protuberances (60). Moreover, connection means (60', 69) are further foreseen to connect in a removable way the covering (65) to the plug element.

Description

TITLE

A PLUG ELEMENT FOR THE REALIZATION OF A LONGITUDINAL CAVITY PROVIDED WITH TRACES IN A REINFORCED CONCRETE

PILLAR AND RELATIVE MACHINERY

Technical field

The present invention refers to the technical field relative to the machineries suitable for the realization of pillars of cement or reinforced concrete.

In particular, the invention refers to an innovative type of plug element that allows to realize reinforced concrete pillars that are particularly idoneous for anti- seismic applications.

Background art

Machineries suitable for the realization of pillars, generally of reinforced concrete, have been known for some time .

Figure 1A shows an example of one or such machineries .

Each machinery forms one or more formworks of containment of the concrete casting. In particular, a plurality of mobile walls are foreseen that delimit the formworks, or die cavities, which reproduce the final form of the pillars that are wanted. For example, in the case of figure 1A, four formworks delimited by four walls are highlighted.

Inside of each die cavity the appropriate pillar reinforcement is arranged, which is formed by a series of reinforcements in steel rod and by connection and encirclement brackets that are arranged transversally in such a way as to form a cage.

Once the cages are arranged, the pouring of the concrete is done, and therefore, with the subsequent maturation of the concrete, the formation of the pillar takes place (see always figure 1A) .

The pillars obtained are then extracted, following the opening of the sides that delimit the formworks. To that aim, both sliding and rotatable sides are foreseen.

Several times, in the realization of such pillars, there is the need for obtaining a coaxial seat with the longitudinal axis of the pillar and that, starting from one of the two basis of the pillar, runs by a small part of the longitudinal length of the same pillar (for example lengths of the cavity on the order of the 80 cm) .

This is because, in the constructive phase, the pillars are overlapped one to the other and therefore, thanks to such coaxial seats, it is possible to insert the bars-iron exiting from the overlying pillar in the cavity of the underlying pillar, realizing a stable connection once the cement has been poured.

In order to create such a cavity, in the current state of the art, a so-called plug-holder device 300 is used, shown in figure 2A of the prior art. The plug-holder device is just a sliding cart with respect to the machinery (for example translatable through actuators) and that foresees one or more long-shaped elements 310 (the plug element) , of a pre-determined section, arranged in such a way that each one of them, when the cart is put next to the formwork, is inserted longitudinally along the respective formwork to which it is placed opposite. In such a manner, when the cement pours, the cement wraps the plug, thus creating the desired cavity in the pillar. The plug element is therefore a sort of box-like long-shaped element applied to the cart and emerging from it. Once the solidification is almost completed, the plug is extracted through a retroaction of the plug-holder cart commanded, for example, by actuators.

As indicated before, the axial cavity has an important structural function because it allows to hold the bars-iron exiting from the overlying pillar, creating a solid structure following the pouring of the cement. Nevertheless, in particular way in anti-seismic applications, in accordance with the Euro-codes and the norms in force, the need is felt for creating a central cavity that in some way improves the adhesion between the cement cast in plant and the one cast subsequently under construction, thus creating a single and very solid structure, more resistant in case of seismic events.

Last but not least, the extraction of the current plug elements is not an easy operation, due to the high value of adhesion that the solidified concrete creates around the plug element itself. Therefore, there is the risk of damaging the form of the cavity during the extraction. It is therefore contextually felt the need for a plug element structured in such a way as to allow its easy extraction from the cavity.

Disclosure of invention

It is therefore the aim of the present invention to provide a plug element to realize a cavity in the pillar that solves said technical inconveniences.

In particular, it is the aim of the present invention to provide a plug element that allows to create a cavity that improves the adherence of the concrete cast in the construction site and therefore of the overlying pillar and that allows, contextually, its easier extraction from the cavity formed.

These and other aims are obtained by adopting a covering (65) to coat externally, at least in part, a plug element (50) suitable for the formation of a cavity (95) in a pillar. In accordance with the invention, the covering foresees one or more protuberances (60) and first connection means (60') configured to result connectable in a removable way with relative second connection means (69) present on the plug element (50) .

The first and the second connection means are dimensioned in such a way as to disengage reciprocally at least in correspondence of the reaching of a predetermined transverse force ( F ) that tends to make the plug element slide with respect to the covering applied on it or vice-versa. For example, in correspondence of a force that tends to extract the plug and with an opposite force that tends to keep the covering in position.

In such a manner, in the extraction phase of the plug element once the cavity has been formed, the covering remains trapped to the walls of the cavity where it has generated the traces and can be removed easily in a subsequent phase. In this way, therefore, the extraction of the plug element is enhanced and internal traces are obtained, which improve the adhesion.

Advantageously, said first connection means (60' ) comprise a metal surface that is collaborating in use with relative one or more magnets (69) present on the plug element (50) .

In a variant, advantageously, said first connection means (60') comprise one or more magnets that are collaborating in use with the metal surface of the plug element (50) .

Advantageously, said first connection means (60' ) are dimensioned in such a way as to disengage from the relative second connection means (69) in correspondence of the reaching of a pre-determined threshold value of a transverse force (F) directed along the length of the plug element to which said covering is applied. Advantageously, said covering can foresee a first metal layer (60') and a second layer (60'') forming said protuberances and extended on said first metal layer (60' ) .

Such a solution allows in a simple way, from the productive point of view, to realize the protuberances on an underlying layer of metal support that, due to its nature, constitutes said first connection means that couple to the magnets.

Advantageously, said second layer (60'') can be of resin.

This solution has the advantage of rendering the covering more easily detachable from the wall of the cavity formed.

Advantageously, said protuberances can be truncated- pyramidal or truncated-cone shaped.

Such shapes have the advantage of guaranteeing a better adhesion of the concrete or cement in the subsequent mounting phases of the overlapped pillars, in accordance with the technical norms in force.

It is also described here the complementary plug element (50), suitable for the formation of a cavity (95) in a pillar. It comprises second connection means (69) for allowing to apply to them in a removable way the covering (65) described above.

Advantageously, if, as said, the first connection means have the shape of a metal plate, then the second connection means (69) comprise one or more magnets (69) or vice-versa .

Advantageously, on the external surface of the plug element, a seat (65') can be foreseen, which forms a sliding guide for the covering (65).

It is also described here the combination of the plug element with the covering, both described above. In particular, it is here described a plug element (50) for the formation of a cavity in a pillar, characterized in that it is covered externally, at least in part, by a covering (65) comprising one or more protuberances (60), and wherein connection means (60', 69) are further foreseen for connecting in a removable way the covering (65) to the plug element.

Advantageously, as described above, said connection means (60', 69) can be of the magnetic type.

In all the solutions described the magnetic coupling has the great advantage of being structurally simple and of allowing an easy adjustment of the value of transverse force (F) to be applied (basically the extraction force of the plug element from the cavity formed) in order to allow the plug to slide with respect to the covering that remains trapped inside without damaging the cavities formed. For example, it is^' enough to apply each time a different number of magnets or magnets of different sizes so as to vary such a threshold force value.

Advantageously, the plug element can foresee, as said, one or more magnets that is collaborating with a metal surface (60') belonging to the covering (65) or vice- versa .

Advantageously, a seat (65') can be foreseen, obtained on the external surface of the plug element and that forms a sliding guide for the covering (65).

Advantageously, said connection means (60', 69) are dimensioned in such a way as to disengage reciprocally in correspondence of the reaching of a pre-determined threshold value of a force (F) directed along the length of the plug element.

It is also described here a plug-holder cart (7, 8) comprising a plug element as described.

It is also described here a machinery (1) for the formation of a pillar comprising a plug-holder cart ( 7 , 8) as described.

Last, it is here described a method for operating the formation of a cavity in a pillar comprising the operations of:

- Arrangement of a machinery (1) for the formation of a pillar, the machinery comprising at least a formwork (110, 120) in which to pour a fluid material for the formation of the pillar;

- Arrangement of a plug-holder device ( 7 , 8) and arrangement of a covering (65) on the external surface of a plug element (50) belonging to said plug-holder device ( 7 , 8), the plug-holder device being translatable between a position in which the plug element (50) results arranged in the formwork and a position in which the plug element is external to the formwork, the covering (65) comprising a plurality of protuberances (60) and being applied in a removable way to the plug element;

- Approaching of the plug-holder device to the machinery in such a way that the plug element results extended in the formwork;

- Pouring of the fluid material and formation of the pillar;

- Extraction of the plug element through a translation of the plug-holder device in such a way as to leave a cavity in the pillar formed;

- And wherein the removable connection between the plug element (50) and the covering (65) arranged on it is configured in such a way that, in the extraction phase of the plug element, the plug element slips with respect to the covering applied on it.

In such a manner, the cavities are easily obtained by removing subsequently the covering remained trapped in the cavity formed. Brief description of drawings

Further features and advantages of the present covering with protuberances of the plug element, the plug element itself and relative machinery 1, according to the invention, will result clearer with the description that follows of some of its embodiments, made to illustrate but not to limit, with reference to the annexed drawings, wherein :

- Figure 1A shows in axonometric view a schematization of a machinery as per the state of the art;

- Figure 2A shows a plug-holder cart as per the state of the art;

- Figure 1 shows an axonometric view of machinery 1 as per the present invention;

- Figure 2 shows a top view of the machinery and highlights the corridors where the die cavities or the formworks are formed (in particular four formworks in the example of figure 2);

- Figure 3 is a front view taken from the part of the plug-holder device and highlights the actuating device that commands the opening by rotation of the lateral side of the machinery 1;

- Figure 4 is an axonometric detail of the plug-holder device or plug-holder cart;

- Figures 5 and 6 are details in lateral view that show always the plug-holder device; in particular, figure 5 shows the entire machinery and highlights a plug-holder cart in extracted position, in which the plug is outside of the die cavity, and the opposite one in position close to the wall of the machinery in which the plug is entirely inside the respective die cavity;

- Figure 7 is an axonometric view of a part that constitutes the plug-holder cart;

- Figure 8 shows a detail of the plug element 50 that is mounted to the plug-holder cart in an exchangeable way;

- Figure 9 shows a detail of connection that allows to connect the plug to its plug-holder device;

- Figures from 10 to 12 show the plug element that is applied to the plug-holder device and covered with a removable covering provided with a plurality of protuberances, preferably truncated pyramidal or truncated cone ones. In this way, an improved shape of the plug is obtained that, thanks to the "removable" protuberances, allows an easy extraction of the plug body and at the same time guarantees the realization of a cavity with better adhesion between concretes cast subsequently thanks to the internal traces obtained;

- Figure 13 shows in detail the cavity obtained in the pillar thanks to the use of such a plug;

- Figure 14 shows such removable surfaces with the protuberances that are applied to the surface of the plug;

- Figure 15 shows a section of channel where the pouring of the pillar takes place;

- Figure 16 shows an exchangeable support that allows to vary the height of the corridor forming the formwork;

- Figure 17 is a section that shows structurally the type of pillar that can be obtained with such a type of machinery;

- Figure 18 shows the application of a covering 60 on the plug;

- Figure 19 shows a partial extraction phase;

- Figure 20 shows the completion phase of the extraction.

Description of some preferred embodiments

With reference to figure 1 it is described, in an axonometric view, a machinery 1 for the formation of pillars in accordance with the invention.

The machinery 1, in accordance with the preferred embodiment of the invention, foresees a first 2 and a second lateral side 3 which, as shown in figure 1, are tilting .

In particular, as better described in detail below, said two lateral sides are connected to the rest of the frame through their inferior side 2 ' and 3' and are therefore rotatable around said inferior sides 2' and 3' through an appropriate actuating device described below. Figure 1, just as a way of example, shows the lateral side 2, partially rotated towards the opening position to allow, as it will result clearer from the continuation of the present description, the extraction of the pillar formed and contained inside it.

Two further fixed front walls (5, 6) and, obviously, a paving 80 (visible also in figure 15 more clearly) serve to complete the external structure of the machinery and to delimit, as clarified below, the formworks or die cavities (110, 120) where the concrete is poured to form the pillars afterwards.

The structure has, therefore, an overall parallelepiped shape, open superiorly, and that forms the formworks of containment of the concrete. Always as shown in figure 1, both the front wall 5 and the front wall 6 are furnished each one with two openings 10 and 11, whose function is described below.

Interposed between the two lateral rotatable sides

(2, 3) (therefore openable/closable) , there is a third wall 4 or dividing wall of the fixed type. In this way, the lateral sides, together with the dividing wall, form two corridors (100, 101) that constitute each one, as better clarified below, two formworks (110, 120) in succession .

In fact, this type of structure, as shown in the axonometric view of figure 1, realizes four formworks, of which two for each corridor. As per figure 1, being the machinery constituted by two corridors 100 and 101 adjacent one to the other, both can be easily reached by the operator. There are no formworks positioned in central areas of difficult access but the user, by going around the machine, has easy access to both the corridors.

This solution, further, allows the adoption of the opening of the sides through a rotation system of the same around their inferior side (2', 3' ) of hinging rather than a translation along the longitudinal axis of the machinery, the whole contributing to a significant saving of encumbrance.

As it can be seen clearly both in figure 1 and figure 2, two plug-holder devices 7 and 8 are then foreseen, identical between them. Such plug-holder devices (7, 8) are translatable along the longitudinal direction of the machinery itself so that each of them, in an independent way from the other, can come close and move apart with respect to the respective front wall 5 or 6 to which it is coupled. In particular, the translation can be controlled automatically in such a way that the plug- holder devices can be brought close to the walls 5 and 6 or move apart from them of a pre-determined quantity.

For example, the top view of figure 2 shows a plug- holder device 7 in a position distanced from its wall 5, while the other plug-holder device 8 results close to the wall 6.

Going on ' with the structural description of the invention, we will now describe better the activating device that commands the rotation of the two lateral sides (2 , 3) .

As shown in figure 3, an actuator 15 is highlighted which obviously foresees an extractable/retractable stem 16. The actuator, as shown in figure 3, is installed below the paving that delimits the formworks and is fixed in a pre-determined point of the frame.

Such types of actuators can be for example of the pneumatic type or of the oleodynamic type, and are well known in the state of the art and therefore not further described in detail in the present description.

The two lateral sides 2 and 3 foresee along their length, at pre-fixed intervals, connection ribs 19 through which a kinematic connection between the stem 16 of an actuator and the side itself takes place. For example, figure 1 shows three ribs 19 that are spaced at equal distance along the length of the side 3, and to each of which is connected an actuator. This is because, according to the length of the side, and therefore of the machinery 1, two or more actuators can be necessary, arranged along the length of the side itself.

Obviously, nothing would impede to realize a machinery of such a length so that just one actuator (appropriately dimensioned) can be enough for activating the side.

Figure 3 shows very clearly, in a front view from the part of the plug-holder device, the two lateral sides 2 and 3 with the ribs 19 that on one side are fixed (for example welded) to the lateral side and on the opposite side connect through a hinging 17 to the stem 16 of the actuator 15. Figure 3 shows the fulcrum hinge 18 between the rib 19, integral to the side, and the frame of the machinery. The hinging 18 is therefore the fulcrum around which the lateral side is engaged to rotate around it and is positioned more or less in correspondence of the inferior side (2', 3')· Obviously, a different position could have been chosen where to position the hinging 18, even if the position indicated in figure 3 is to be considered the best one. Operatively, with reference to the example of figure

3, when the stem 16 is extracted from the actuator 15 to which it belongs, the stem applies a force F in the point of connection 17 to the rib 19 in the direction of the arrow of figure 3, thus obliging the side 2 to rotate in clockwise direction around the hinging point 18, that is in the closing direction as indicated in the figure. Obviously, when the stem retracts in the opposite direction, it drags the side in an opposite rotation. Any intermediate position maintained by the stem 16 maintains the relative side in a pre-determined intermediate position between a closing and an opening position.

The same kinematism is obviously foreseen for the opposite lateral side 3.

Figure 3, for description completeness, shows supports 20 the lift from the ground the structure that has been described so far.

Going on with the structural description of the invention, figure 4 now shows in detail the plug-holder device (7, 8) .

As it is shown in the axonometric detail of figure

4, the plug-holder device is formed by a wall 30, which is arranged in a sliding way with respect to the structure of the machinery that defines the formworks and therefore with respect to the assembly of the lateral sides, its respective front wall (5, 6) and obviously the paving of the formwork. In particular, as already anticipated in figure 1 and 2, the wall 30 can translate up to coming into contact with the relative front wall (5, 6) where it is mounted, or move apart from it.

The wall 30 foresees two long-shaped blocks 50 and with a pre-determined section (that is two box-like long- shaped elements) , for example in this case rectangular and called also plug elements or simply plugs. The blocks are therefore similar to two beams fixed to the wall 30 and emerging from it orthogonally in such a way that in use they result directed towards its own lateral wall 5 or 6.

The dimensions of the blocks 50 can be in terms of length in a range between the 50cm and the 90cm and, preferably, between the 60cm and the 80cm.

The rectangular section can have lengths of about 30cm x 40cm but, as then clarified below in the present description, these measures and the shapes of the blocks can obviously vary according to the production needs of the pillar.

The two blocks are positioned in such a way and have such a size that, when the wall 30 is put close in contact with the relative front wall (5, 6) , the blocks are inserted entirely in the area of the formworks through the openings 10 and 11 obtained in the relative front parts (5, 6) to which they are put close. When the plug-holder device is translated in the opposite direction, the translation is controlled in such a way that the plugs exit completely from the internal area delimited by the two front walls (5, 6) .

The walls (5, 6) with the relative holes are therefore positioned in such a way as to create a flat base of the pillar with the cavity 95 in axis as per figure 17.

Figure 5 shows a lateral view of the entire machinery 1 and highlights, just as a way of example, a plug-holder device in retracted or extracted position and the other one in a position close to the wall (5, 6) .

Figure 6 shows a more precise detail of the plug- holder device, while figure 7 is an axonometric view of a part of such a plug-holder device (in particular in figure 7 the plugs 50 have been omitted) .

With reference to figure 6, the sliding system is highlighted that allows the translation of the single plug-holder device along the longitudinal direction of the machinery. This is easily obtained through a platform 31 (shown in figure 7) that connects orthogonally to the wall 30 in such a way that the assembly of the wall 30 and of the platform 31 are L-shaped.

The platform 31 is formed by two lateral section bars 32, with C-shaped section, distanced between them and placed frontally one to the other and connected to the wall 30. On the opposite side a traverse 33 is foreseen, eventually accompanied with the presence of further reinforcement intermediate traverses 33.

The two lateral section bars 32 foresee rotatable wheels 34 fixed to them and directed towards the outside. Figure 7 shows two per section bar but obviously any number can be foreseen, without for this moving apart from the present inventive concept.

The platform 31 is inserted inside a fixed sliding binary 35, arranged in the fixed frame of the machinery (see for example figure 6) and therefore assembled slidingly thanks to the help of the wheels 34.

For example, precisely the detail of figure 4 highlights very well how the platform 31 is held between the binaries 35 placed under the paving of the machinery and also them in fact formed by two C-shaped beams to create a sliding level for the wheels 34. At this point a simple linear actuator, of the type, for example, similar to the actuator 15 described above, can be used to command the translation in a direction or in the opposite direction of the entire plug-holder device.

It is therefore preferably arranged a linear actuator for each plug-holder device, so that they have independent movements.

Nothing would exclude a solution with a double actuator that contextually activates simultaneously both plug-holder devices, even if it would have to have an adequate length.

Figure 6 schematizes an actuator 37 that commands the movement of the plug-holder device, placed inside the fixed side 4 which is appropriately dimensioned to form a holding channel. This solution obviously allows a significant saving of encumbrance and allows to maintain the actuator and its system clean and protected.

Going on with the structural description of the invention, figure 8 shows the single block 50 (indicated precisely as a plug in the technical jargon) removed from the frame 30. Figure 9 instead shows a detail of connection and highlights how such blocks 50 can be connected in a removable way.

The block 50 foresees a ball joint pin 51 with fixing bolt 52. The ball joint pin allows to facilitate the positioning in geometry and at right angles with the subsequent tightening of the plug.

This solution, as clarified below, allows above all to exchange in a fast and simple way a plug with a different one, for example of a different shape and/or size .

With the plugs normally in use in the state of the art, further accessory shapes cannot be obtained (in grain or corrugated) , useful both for facilitating on the one hand the extraction of the plug and on the other hand to realize a better adhesion surface between concretes cast subsequently in other phases in the cavity.

The solution to such a problem is shown with reference to the subsequent figures from 10 to 12 in which the block or plug 50 is shown that is appropriately coated on its sides with a plurality of reliefs 60 of truncated pyramidal shape, preferably but not necessarily. Such reliefs rest on a covering surface 65 that is applied on the plug in a removable way and that forms an external covering of the removable plug.

In particular, in accordance with a first possible solution, the removability is obtained through a connection of the magnetic type.

In particular, the covering on which the reliefs are realized has in fact the shape of a metal plate, while, on the plug, one or more discrete magnets are built in.

Obviously, the inverse solution (magnets built in in the covering and metal plug) could be implemented.

Another system of "removable" connection could foresee glues and/or resins of low adhesion value.

A further connection system could foresee fastening couplings (for example receiving pin-seat) arranged in such a way as to disengage reciprocally once a predetermined value of "tangential" traction has been reached along the covering or plug plane.

The use of such removable plugs has the following advantage. When the plug is extracted from the formwork, once the cement or concrete has been poured, the covering 65, having the reliefs 60, remains trapped in the cavity obtained in the pillar formed, to be comfortably removed afterwards .

In fact, by appropriately dimensioning the magnetic attraction force, it can be obtained that, during the extraction of the plug, the covering "slips" on the plug itself, remaining trapped in its position inside the cavity in which it has generated the traces. This operation is facilitated by the fact that the extraction generally takes place once the solidification of the concrete has been almost completed. The reliefs 60 in fact remain blocked in the solidified traces that have created in the wall of the cavity and, for that reason, the extraction movement of the plug creates a tangential force that allows the sliding and therefore the separation of the covering with respect to the plug.

The expert in the field will be able to easily appreciate that, in accordance with such a solution, any threshold adhesion value is easily dimensional between plug and covering (either magnetic or of another type) so that it would be enough even a minimum extraction force of the cart to cause the reciprocal sliding between covering and plug. This is useful if, for example, the extraction of the plug was made, also when the concrete has just been poured and therefore has not solidified completely.

The technical effect is that of tracing the cavity of the pillar in such a way that, in use, the pillar connects better to an overlying pillar through the subsequent concrete or cement cast that has a better adhesion precisely thanks to such traces 60' . In addition, obviously, the operation of extraction of the plug is simplified since it slips away easily and without risk of damaging the cavity formed.

Figure 13, just as a way of example, shows a part of a finite pillar in which such traces 60' obtained with the covering 65 are highlighted.

Figure 14 shows some of such coverings 65 when detached from the plug.

Such coverings can for example be made in the shape of an underlying metal plate 60' on which the resin is poured that forms an external covering layer 60'' provided with the plurality of protuberances.

The use of a resin has the advantage of having a low adhesion with the solidified concrete and therefore of enhancing its subsequent removal and a strong resistance to scratches and cuts with a consequent greater duration.

Once the cavity has been formed, the plug-holder cart slides in the direction of extraction, therefore the plugs exit from the cavities but the coverings remain trapped in position. The subsequent removal of the coverings is then made.

The plugs are generally coated on all four sides with such a covering but, obviously, a covering of just one or more sides could be arranged.

Last, the covering could be substituted by discrete protuberances .

As further described in figure 14, it is also foreseen a linear seat 65' obtained on each side where the covering is applied. Its width is such as to hold inside it the covering and its depth is such that, as for example shown in figure 11, only the protuberances exit from it. In this way, the thickness of the covering is included in the plug, therefore without altering the real height of the plug and, above all, such seats form sliding binaries that guide the sliding direction of the covering with respect to the plug. In this way, there is no risk that during the extraction the covering moves by rotation with respect to the underlying plug where it leans.

Always with reference to figures from 10 to 12, a pin 61 is highlighted which serves to hold inside the cast a glass-shaped cylindrical element.

In this way, the bottom of the cavity obtained in the pillar foresees a further coaxial cavity of inferior diameter and obviously equivalent to the glass mounted on the pin 61. In this way, as also shown in figure 13, in the bottom of the cavity 200 of the pillar a further cavity will be realized that serves to apply in a * removable way a pipe 200 which is necessary and important for the overlapped mounting between the pillars. The fact that the pipe is removable simplifies a lot the operations of mounting of the structure with overlapped pillars. In the structural detail, the pin 61 is formed by two disks 62 and 63 distanced between them and connected through a central axis 64. The pin can be of the screwable type, screwed to the front face of the plug.

This solution has the advantage of avoiding the block or the accidental gluing of the glass-shaped cylindrical element that is applied on such a pin due to the cement grout. In fact, the contact between the parts is minimized and limited to the two disks 62 and 63 and therefore, also in case of accidental penetration of concrete or cement that then hardens, the removal of the glass from the pin 61 is possible in a very easy way.

With reference to figure 12 two further lateral pins 64 are highlighted, applied to the plug 50 through openings arranged on the side of the covering 65 in a removable way. Procedurally, the plug slips and the pin creates a hole and remains in the cement together with the covering. At this point covering and pin are removed.

Figure 15 well highlights, in addition to what has already been described, the assembly that constitutes the real paving of the corridor that in fact forms the formwork. In particular, the machinery forms a fixed frame that has an inferior part 82 which is also visible in figure 4 and that allows to connect, as already described, the plug-holder device (7, 8) in a translatable way with respect to the frame of the machinery 1.

Such a frame 82 creates also a support surface for a vertical support 81, shown singularly also in figure 16. In this way, the height with respect to the ground of the surface 80 can be positioned and adjusted, which in fact forms the paving of the corridor. In this way, by substituting every time support surfaces 81 of different heights, it is possible to vary the height of the corridor and therefore of the formwork. Such vertical support 81 is in fact a plate element that forms superiorly and inferiorly a support surface. Superiorly the paving 80 leans and inferiorly it leans on a beam of the fixed frame.

In order to guarantee a stable anchorage, plates 85 are foreseen that form, as also shown in figure 15, holding edges.

Preferably, being the sizes of the pillars standardized, three different measures of the vertical support 81 are enough to obtain the desired sizes of section of the pillar.

Nevertheless, remaining valid the fact that the paving 80 is adjustable in height, nothing would impede to realize a support 81 similar to a lifting jack, also pantograph-like to operate the change of a wheel of a car, therefore allowing to adjust at will in a continuous way the height of the paving desired. The jack could be activated either manually or in an automatic way through a specific engine or actuator.

As it will be clarified below in the method of use of such a machinery, it is obvious that the exchangeability of the plug is important precisely in virtue of a possible adjustment of height of the paving 80. If the paving is lowered it is necessary to select a plug of greater section since, in use, it has to result always extended in a coaxial way with the formwork and form a cavity of a certain size. Likewise, if the size of the blocking device is not selected correctly with respect to the height of the paving selected, it will not be able to delimit correctly the formwork or either grasp the exiting bars-iron.

Going back to figure 1 and 2, for completeness, the two walls 70 are shown which delimit from the opposite part to the plug the formwork and that serve for the formation of the flat base of the pillar opposite to the one where the cavity is obtained.

Two flat plates 70 are therefore foreseen for each corridor so as to form two formworks for each corridor. In particular, figure 2 shows, for example, that the corridor 100 (and in an identical manner also the corridor 101) foresees two formworks (110, 120) distanced one from the other by the "gap" 150 destined to hold the bars-iron of reinforcement exceeding from the pillar.

The flat plates can foresee a pin that is very similar to the pin of the plug to create a cavity.

Figure 17, just for clarity purposes, describes briefly the type of pillar that can be obtained with such a machinery in such a way as to clarify the subsequent description of use of the machinery itself.

The pillar, of concrete or reinforced cement, foresees inside it a reinforcement which, as shown in the internal dotted lines, foresees a plurality of long longitudinal bars-iron 91 (for example four, six, eight or more) , which exit in part from the inferior base 93 of the pillar. A plurality of brackets 92 are foreseen, distanced one from the other at variable pitch and that connect with the longitudinal bars-iron in order to realize a cage.

The superior base 94 of the pillar foresees a central cavity 95 which is coaxial with the longitudinal axis of the pillar and that terminates at the end with a further cavity 95' of inferior diameter and whose function is that of allowing the removable application of a pipe.

The pipe serves as spacer when the pillar, like that of figure 21, is overlapped to another pillar, for example. In that sense, the pipe, not represented in the figure for simplicity purposes but shown in figure 13, has such a length as to exit for a certain quantity from the cavity 95 when inserted from the opposite end in the receiving cavity 95' .

The cavity 95 presents (as also shown in figure 13) lateral walls that delimit it and which are traced with a plurality of truncated pyramidal-shaped cavity 60' .

The inferior base 93 also foresees a cavity 93'

(obtained with the pin applied to said plate 70) that serves precisely to hold the end of a pipe inserted in the cavity 95' of an underlying pillar.

The plate 70 can be conformed on its sides of openings that allow the passage of the exiting bars-iron 91 .

Having described the product that can be obtained with such a machinery, and having structurally described the different parts of the machinery, the description of functioning of the machinery will result now clearer.

Initially, each reinforcement is arranged inside the formwork with the exiting bars-iron 91 that terminate in the part of gap 150. The plates 70 and the walls (5, 6) form the flat bases.

The coverings 60 with protuberances on the plugs are arranged. Figure 18 shows the application phase of the covering on all four sides in the relative sliding seats 65' obtained on the surface of the plug.

The translation of the two plug-holder carts is made close to the walls (5, 6) in such a way that the plugs penetrate in the formworks.

The pouring of the concrete is done and its solidification, at least partial, is waited. With a retroaction motion the extraction of the carts is done, extracting the plugs from the cavity formed.

Figure 19 shows, to that aim, a portion of the pillar formed and the extraction phase that shows the plug partially extracted. Figure 19 shows the force F of extraction of the plug that commutes to a transverse force F that makes the plug slide with respect to the covering that remains trapped precisely thanks to the protuberances formed .

As shown in figure 20, once the extraction has been completed, the coverings with protuberances will remain blocked in the cavity and it will be possible to remove them easily, for example manually, from the cavity itself.

The result is a pillar as that of figure 17.

Figure 18 shows the realization of the covering in accordance with a first metal layer 60' and the overlying layer 60'' having the protuberances, preferably of resin.

Claims

CLAI S

1. A covering (65) for covering externally a plug element (50) suitable for the formation of a cavity (95) in a pillar characterized in that it comprises one or more protuberances (60) and first connection means (60') configured to result connectable in a removable way with relative second connection means (69) present on the plug element (50) .

2. A covering (65), as per claim 1, wherein said first connection means (60') comprise a metal surface collaborating in use with relative one or more magnets (69) present on the plug element (50).

3. A covering (65), as per claim 1, wherein said first connection means (60') comprise one or more magnets collaborating in use with the metal surface of the plug element (50) .

4. A covering (65), as per one or more of the preceding claims from 1 to 3, wherein said first connection means (60') are dimensioned in such a way as to disengage from the relative second connection means (69) in correspondence of the reaching of a predetermined threshold value of a force (F) directed along the length of the plug element to which said covering is applied.

5. A covering (65), as per one or more of the preceding claims, wherein said covering foresees a first metal layer (60') and a second layer (60'') forming said protuberances and extended on said first metal layer (60' ) .

6. A covering (65), as per claim 5, wherein said second layer (60'') is of resin.

7. A covering (65 as per one or more of the preceding claims, wherein said protuberances are truncated- pyramidal or truncated-cone shaped.

8. A plug element (50) suitable for the formation of a cavity (95) in a pillar characterized in that it comprises second connection means (69) to allow to apply to it in a removable way a covering (65) in accordance with one or more of the preceding claims from 1 to 7.

9. A plug element (50) , as per claim 8, wherein said second connection means (69) comprise one or more magnets ( 69) .

10. A plug element (50), as per claim 8 or 9, wherein a seat (65') is foreseen, obtained on the external surface and that forms a sliding guide for the covering ( 65 ) .

11. A plug element (50) for the formation of a cavity in a pillar, characterized in that it is coated externally, at least in part, by a covering (65) comprising one or more protuberances (60), and wherein connection means are further foreseen (60', 69) for connecting in a removable way the covering (65) to the plug element.

12. A plug element (50), as per claim 11, wherein said connection means (60', 69) are of the magnetic type.

13. A plug element (50), as per claim 11 or 12, wherein the plug element foresees one or more magnets collaborating with a metal surface (60') belonging to the covering (65) .

14. A plug element (50), as per claim 11 or 12, wherein the plug element is of metal and the covering (65) foresees one or more magnets that are collaborating with the plug element.

15. A plug element (50) , as per one or more of claims from 11 to 14, wherein a seat (65') is foreseen, obtained on the external surface and that forms a sliding guide for the covering (65).

16. A plug element (50), as per one or more of the preceding claims from 11 to 15, wherein said connection means (60', 69) are dimensioned in such a way as to disengage reciprocally in correspondence of the reaching of a pre-determined threshold value of a force (F) directed along the length of the plug element .

17. A plug-holder cart (7, 8) comprising a plug element as per one or more of the preceding claims from 11 to 16.

18. A machinery (1) for the formation of a pillar comprising a plug-holder cart (7, 8) in accordance with the preceding claim 17.

19. A method for operating the formation of a cavity (95) in a pillar comprising the operations of:

- Arrangement of a plug-holder device (7, 8) and rearrangement of a covering (65) on the external surface of a plug element (50) belonging to said plug-holder device (7, 8), the plug-holder device being translatable between a position in which the plug element (50) results arranged in the formwork and a position in which the plug element is external to the formwork, the covering (65) comprising a plurality of protuberances (60) and being applied in a removable way to the plug element;

- Pouring of the fluid material and formation of the pillar;