WO2018002807A1

WO2018002807A1 - Machinery, plant and process for producing artificial stones

Info

Publication number: WO2018002807A1
Application number: PCT/IB2017/053796
Authority: WO
Inventors: Francesco Ferraiolo
Original assignee: Officine Maccaferri S.P.A.
Priority date: 2016-06-29
Filing date: 2017-06-26
Publication date: 2018-01-04
Also published as: BR112018075357A2; CN109476038A

Abstract

Machinery (10) for producing artificial stones comprises a hopper (30) which is capable of containing an admixture of least cement and water and conveying it in moulds provided into a rotary formwork (40); there are provided on two opposing walls of the hopper (30) two vibrators (36) which are capable of imparting a vibration to the hopper. A process for producing artificial stones comprises the steps of mixing at least cement and water, transferring the admixture obtained to a hopper (30), imparting a vibration to the hopper by actuating two vibrators (36) which are arranged on two opposite walls of the hopper (30), pouring the admixture from an opening (34) of the hopper (30) into at least one mould form of a rotary formwork (40) in order to form at least one artificial stone, rotating the rotary formwork in order to remove, as a result of gravitational force, the at least one artificial stone.

Description

MACHINERY, PLANT AND PROCESS FOR PRODUCING ARTIFICIAL STONES

The present invention relates to machinery, a plant and a process for producing artificial stones and in particular artificial stones which are intended to be used as a filler material, for example, for gabions.

It has been known for some time to use gabions for various applications, such as, for example, the production of containing structures. Usually, the gabions are assembled directly at the site of use and are then filled with a suitable filler material. Preferably, the material used is composed of stones collected in situ. For this reason, gabions are a particularly economic and advantageous

solution, generally only requiring the transport of the empty gabion which is suitably folded.

In some locations, however, stones are not present in

sufficient quantities to fill the necessary gabions. In these cases, it is normally necessary to take the stones from a quarry and to transport them to the installation site of the gabions. Naturally, these operations require a substantial economic engagement, particularly in the case of great construction sites, which may also require hundreds of thousands of cubic metres of stone.

An object of the present invention is to provide an economic and effective solution to the problem of the availability of suitable material for filling gabions.

In order to achieve these above-indicated objects, the present invention relates to machinery, a plant and a process for producing artificial stones as in the appended claims. The present invention allows the production of cement blocks to be used as artificial stones for filling gabions, without using natural stones from quarries, thereby significantly reducing the production costs and times of a structure for reinforcing gabions. Naturally, the use in gabions is only one of the possible advantageous uses of the artificial stones produced with the present invention. For example, they can be used for filling anti-erosion mattresses or the like, as well as for producing supporting walls or road

foundations. In the context of this description, the

expressions "artificial stone" and "block" will be used alternatively with the same meaning.

According to the present invention, the machinery comprises a hopper which is provided with a lower opening and which is capable of containing an admixture of at least cement and water and conveying it through the lower opening, and a rotary formwork which comprises a rotatable cylindrical member which is provided with a plurality of moulds, the rotary formwork being arranged below the hopper, so that at least one mould is arranged in the region of the lower opening of the hopper in order to receive the admixture from the hopper; the machinery further comprises on the hopper two vibrators, which are preferably fixed to bars, which are in turn fixed to the external walls of the hopper, in order to impart a vibration to the admixture which is contained therein and to fluidize it, as will be better described below .

Advantageously, the machinery provides for a plurality of removable moulds which can be selectively fixed to the cylindrical member; according to a particularly effective variant, there are provided between the moulds and the cylindrical member anti-vibration elements, which are

preferably constituted by disks of shock-absorbent material which are arranged between the moulds and cylindrical member and through which connection elements which fix the moulds to the cylindrical member extend. Preferably, those anti- vibration elements are rubber disks.

The present invention also relates to machinery for producing artificial stones which comprises a hopper which is provided with a lower opening and which is capable of containing an admixture of at least cement and water and of conveying it through the lower opening, and a rotary formwork which comprises a rotatable cylindrical member which is provided with a plurality of moulds, the rotary formwork being

arranged below the hopper, so that at least one mould is arranged in the region of the lower opening of the hopper in order to receive the admixture from the hopper, wherein the moulds can be removed. Preferably, each mould comprises a plurality of different mould forms, each of which is capable of forming an artificial stone, and even more preferably the mould forms have different dimensions.

Advantageously, each mould is monobloc; preferably, the greater dimension of each mould corresponds approximately to the width L of the formwork.

Preferably, the mould forms have lateral walls which are inclined and smoothed corners.

According to a variant, the machinery further comprises a dispensing nozzle for a detaching liquid for spraying the detaching liquid into the moulds. According to a variant, there are provided at the ends of each mould housings for connection elements with respect to the cylindrical member, the housings comprising a base wall in which there are formed holes for the connection elements and an upper wall for protecting the connection elements from the cement .

The present invention further relates to machinery for producing artificial stones comprising a hopper which is provided with a lower opening and which is capable of containing an admixture of at least cement and water and of conveying it through the lower opening, and a rotary formwork which comprises a rotatable cylindrical member which is provided with a plurality of moulds, the rotary formwork being arranged below the hopper, so that at least one mould is arranged in the region of the lower opening of the hopper in order to receive the admixture from the hopper, the machinery further being provided with wheels for the movement thereof during production.

In this manner, it is possible to remove directly on the ground the artificial stones, at the site of drying, without requiring the use of transport belts or other movement systems in order to move the blocks which are formed from the production location to the drying location.

In this case, the removable moulds may also be selectively fixable to the cylindrical member and are preferably

monobloc .

Therefore, the present invention provides for machinery which is particularly robust, durable and easy to maintain as a result, for example, of the presence of removable moulds. Furthermore, it is readily able to be transported and can be used in a plant, to which the present invention also relates and which is simple and economical.

In fact, the invention also relates to a plant for producing artificial stones, comprising a mixing station of at least cement and water and machinery having the characteristics set out above. If the machinery is provided with wheels, it is movable in a deposit zone.

The invention also relates to a process for producing

artificial stones, comprising the steps of:

- mixing at least cement and water,

- transferring the admixture obtained to a hopper,

- imparting a vibration to the hopper by actuating two vibrators which are arranged on two opposite walls of the hopper,

- pouring the admixture from an opening of the hopper into at least one mould form of a rotary formwork in order to form at least one artificial stone,

- rotating the rotary formwork in order to remove, as a result of gravitational force, the at least one artificial stone .

The invention also relates to a process for producing

artificial stones, comprising the steps of:

- mixing at least cement and water,

- transferring the admixture obtained to a hopper,

- rotating the rotary formwork and at the same time moving the machinery in order to remove, as a result of

gravitational force, the at least one artificial stone on the ground . The invention also relates to a process for producing

artificial stones, comprising the steps of:

- providing machinery for producing artificial stones

comprising a hopper and a rotary formwork which comprises a cylindrical member which can rotate about the axis thereof,

- mounting a plurality of removable moulds on the cylindrical member,

- mixing at least cement and water,

- transferring the admixture obtained to the hopper,

- pouring the admixture from an opening of the hopper into at least one removable mould in order to form at least one artificial stone,

Other characteristics and advantages will be appreciated from the following detailed description of a preferred embodiment of the invention with reference to the appended drawings which are provided merely by way of non-limiting example and in which:

Figure 1 is a perspective view of machinery for producing artificial stones,

Figure 2 is a side view of the machinery illustrated in

Figure 1,

Figure 3 is a perspective view of a rotary formwork, forming a portion of the machinery of Figure 1,

Figure 4 is a front view of the rotary formwork of Figure 3, Figure 5 is a side view of the formwork of Figure 3,

Figure 6 is a side view of a multiple mould which can be used in the formwork of Figure 3,

Figure 7 is a plan view of the multiple mould of Figure 6, Figure 8 is the cross-section along the line of section A-A of Figure 6,

Figure 9 shows a detail of the lower portion of a hopper, forming a portion of the machinery of Figure 1,

Figure 10 shows a detail of a mixer, which can be used inside the hopper,

Figure 11 is a general diagram of a plant comprising the machinery of Figure 1,

Figure 12 is a view of a portion of the plant of Figure 11, in the direction of the arrow XII,

Figure 13 shows the step of supplying the admixture to the machinery for producing the artificial stones.

With reference now to Figures 1 and 2, machinery 10 for producing artificial stones comprises a support frame 20, a hopper 30 and a rotary formwork 40. The general electrical switchgear of the machinery is designated 28.

The support frame 20, which is also sometimes referred to as a "mount", comprises a plurality of bars 22 which are

preferably of metal and which are connected to each other so as to form a structure, to which the components of the machinery 10 are fixed. Furthermore, it is preferably mounted on wheels 24 in order to allow the machinery to be moved.

The hopper 30 and the rotary formwork 40 are fixed one above the other to the support frame 20.

The hopper 30 has an upper opening 32 which is capable of receiving premixed mortar or concrete and a lower opening 34 which is capable of supplying the material to the rotary formwork 40 below. There is mounted inside the hopper 30 a mixer 38; furthermore, there are provided on the outer side two vibrators 36 which are capable of imparting a vibration to the hopper itself and to the contents thereof. These characteristics will be discussed in greater detail below with reference to Figures 9 and 10.

The rotary formwork 40 which can be seen better in Figures 3, 4 and 5 comprises a cylindrical member 42 having a width L and a diameter D and to the outer surface 44 of which there are fixed a plurality of moulds 50. The rotary formwork is capable of rotating about a shaft 48 which extends through the axis thereof as a result of a motor and a step-down mechanism (not visible in the Figures) which control the rotation speed of the formwork 40 on the basis of parameters, such as, for example, the density of the admixture used.

The formwork 40 is positioned below the hopper, in a state aligned with the lower opening 34 of the hopper itself, so that the admixture can be poured from the hopper inside the moulds 50 which are located in the upper portion of the formwork 40. The rotary formwork is rotatable about the axis 48 in the direction indicated by the arrow G. A protection element 49 for closing the moulds 50 is provided beside the rotary formwork 40.

With reference now to Figures 6 to 8, according to the preferred embodiment the moulds 50 are removable and multiple moulds: each multiple mould 50 is preferably monobloc, constructed in a single casting operation. Each mould 50 comprises a plurality of mould forms 52 which preferably have a rectangular base for a maximum utilization of the lateral surface of the formwork. The overall length of the mould corresponds approximately to the width L of the formwork.

The mould forms 52 have different dimensions: in the example illustrated, they have four different dimensions 52a, 52b, 52c, 52d so as to obtain artificial stones having four different forms and dimensions. If it is desirable to use them for filling gabions, in fact excessive regularity would not be advantageous. Conversely, for stable and effective filling it is necessary to provide for artificial stones having various dimensions. The use of multiple moulds with mould forms of different dimensions thereby allows the production at the same time of stones having different dimensions without any need for using blocks obtained from different machines for the same gabion.

In order to promote the removal of the blocks from the mould forms, they preferably have lateral walls 54 which are slightly inclined and smoothed corners 56. Furthermore, they show continuity between the lateral walls 54 and the base 55 which therefore do not have joints or other connections.

Still in order to promote the removal of the blocks, there can be used a detaching liquid which is sprayed from a suitable nozzle in the moulds before they are filled with the cement-containing admixture. The nozzle, which cannot be seen in the Figures, is mounted inside a carriage 58 (Figures 1 and 2) which can be moved over the entire width L of the formwork so as to be able to spray all the mould forms 52 of each mould 50.

There are provided at the ends of each mould housings 60 for the connection elements with respect to the cylindrical member 42. Typically, the connection elements comprise screws 62 and nuts 63. The housings 60 comprise a base wall 64, in which there are formed holes 66 for the screws 62, and an upper protection wall 68 which prevents the cement which is poured from the hopper from covering the screws 62. The housings 60 are open laterally in order to allow ready access to the screws 62 if it is desirable to replace the moulds. As can be seen in Figures 3 and 5, anti-vibration elements 70 are present between the moulds 50 and the cylindrical member 42; these are disks of a shock-absorbent material, that is to say, which absorbs the vibrations (for example, rubber), which are arranged between the moulds and the cylindrical member and through which the screws 62 extend. In this manner, any vibrations of the shaft 48, including those caused by the vibrators 36 of the hopper, are not transmitted to the moulds .

It is further known that the use of removable moulds allows a high level of flexibility because, in order to obtain blocks having different dimensions, it is simply necessary to replace the moulds which are mounted on the machinery. In particular, however, it is particularly advantageously possible to replace a damaged mould without having to replace the entire formwork. In fact, it is considered that the machinery 10 is intended to be used on construction sites in which rubble is abundant, the operators are not necessarily skilled and therefore damage to a mould is unfortunately not an impossible event.

Figure 9 shows the lower portion 31 of the hopper 30. The lower opening 34 of the hopper 30 is rectangular, with the greater dimension thereof extending parallel with the

direction of the axis of the formwork.

A pair of bars 80 with a U-shaped cross-section is fixed externally to the hopper in the region of the lower opening 34. The pairs of bars 80 are arranged parallel with the direction of the axis of the formwork and extend over the entire length of the hopper. Each U-shaped bar is fixed to the hopper so as to form, with the lateral wall 33 of the hopper, a closed channel 82.

A securing plate 84 for a vibrator 36 is externally fixed to each bar 80. In this manner, it is possible to use a so- called semi-dry concrete, that is to say, having a reduced percentage of water: in fact, the vibration fluidizes the semi-dry concrete, making it possible to pour it into a formwork. When the concrete is poured into the mould form, with it no longer being subjected to the vibrations, it loses fluidity and therefore it is possible to remove it

immediately from the formwork without any need for pressing it or waiting for it to dry.

The vibration, allowing the use of a concrete with a reduced percentage of water, allows the production times of the artificial stones to be shortened. At the same time, it allows the concrete to be poured in the fluid state by improving the uniformity of the filling of the moulds and therefore preventing cracks and fractures in the stones produced .

Since the concrete is sufficiently fluidized, however, it is necessary for the vibration to be uniform in all the

material, leading to the need to use at least two vibrators and two bars which act as propagators of the vibration. The Applicant has found in fact that the U-shaped formation of the bars and the above-described positioning thereof allow propagation in an effective manner of the vibration over the entire length of the hopper and consequently all the material contained therein. In the absence of those bars, however, the admixture is subjected to vibrations differently in

accordance with the location in the hopper at which it is located and consequently the portions of admixture which are not subjected to sufficient vibrations may have difficulty in filling the mould forms.

The Applicant has further established by experimentation that it is important to reduce to the greatest possible extent the vibrations which are imparted to the formwork and which increase the occurrence of breakage of the blocks

significantly.

For this reason, in a variant which is not illustrated, the support frame 20 is subdivided into two portions: a lower portion, to which the rotary formwork is fixed, and an upper portion, to which the hopper is fixed. The two frame portions are connected with the interposition of a material which absorbs the vibrations, for example, a rubber material, in such a manner that the vibrations imparted to the hopper are not transferred to the formwork.

Figure 10 shows a mixer 90 which is preferably provided inside the hopper 30 in order to continuously mix the

material contained therein. The mixer 90 comprises a rod 92, about which there are arranged a plurality of blades 94 which are spaced apart from each other longitudinally and radially. The rod 92 which is actuated by an actuator which is not illustrated rotates about itself, causing the rotation of the blades 94 which thereby mix the material. In this manner, the mixer not only ensures the homogeneity of the admixture but also acts on the vibrators and on the U-shaped bars together in order to allow a uniform vibration to be imparted to all the admixture .

With reference now to the process for producing artificial stones, the hopper is filled with material which is pre-mixed in a suitable mixer and which is separate from the machinery 10 for producing the artificial stones. Typically, cement and water are mixed, with the optional addition of sand and/or gravel, in order to obtain mortar or concrete.

The pre-mixed admixture is introduced into the hopper 30 where the mixer 90 continues to mix it. The vibrators 36 with the action thereof fluidize the admixture, which descends through the lower opening 34 of the hopper 30 and fills the mould forms 52 of the mould 50 which is arranged in the region of the lower opening 34. The formwork 40 rotates in the direction of the arrow G so that a new mould 50 which is empty is positioned below the opening of the hopper while the mould which has previously been filled is moved away. As a result of the effect of the movement of the formwork, the filled mould is closed at the upper side by the protection element 49 which retains the blocks of cement in the mould forms until they are removed. Substantially, the protection element 49 is a plate which, not being caused to rotate together with the formwork, closes the moulds 50 immediately after they have been filled and keeps them closed until, as a result of the effect of the rotation of the formwork, they are arranged so as to face the deposit surface. When the mould is located in this position, with it no longer being closed by the protection element 49 and having the mould forms 52 with the openings directed towards the bottom, the material inside the mould forms is discharged as a result of the effect of gravitational force in the form of blocks having predefined dimensions. The function of the protection plate 49 is therefore to prevent the blocks from falling too soon and from too high a height and from becoming broken.

Although the machinery may be used effectively in order to deposit blocks on a transport belt, without any need to move the machinery itself, the Applicant has provided for mounting the support frame on wheels 24 so as to be able to move the machinery 10 during the production of the blocks, which can be placed directly on the ground. In this manner, the overall plant is significantly simplified with a reduction of the costs and risk of breakdowns.

With reference now to the general diagram of the production plant of Figure 11, the plant 100 comprises a mixing station which comprises a container 110 in which cement and water are mixed with the optional addition of sand and/or gravel, in order to obtain mortar or concrete. It is known that at some sites there may be wide availability of sand or gravel, though there are not available stones having a sufficiently great size to be directly used in the gabions.

There may also be added to the admixture synthetic and/or metal fibres in order to increase the resistance of the artificial stones which it is intended to produce as well as chemical additives.

The admixture obtained in this manner is transferred to a dispensing station 120 which comprises two dispensing

apertures 122, one of which is visible in detail in Figure 12. A lifting carriage 130 which is provided with a hopper 132 takes the admixture from the dispensing aperture 122 and transfers it to machinery 10 for producing artificial stones. In the plant of Figure 11 there are illustrated two

dispensing apertures 122, with two lifting carriages 130 in the process of being loaded. It is known that this system for supplying admixture to the machinery 10 does not interfere with the possibility of the machinery itself moving during production . The machinery 10 for producing artificial stones is moved during the entire production so that it deposits the blocks directly on the ground in a deposit zone 140; Figure 11 indicates a possible trajectory 150 of the machinery in the deposit zone 140. At the end of a processing shift lasting 8 hours, the machinery is preferably moved into a different deposit zone 140' where it will deposit blocks for the subsequent 8 hours.

In the deposit areas 140, 140' , the blocks are left at least for the time necessary for drying. The complete drying generally requires approximately 8 hours after which the blocks can be used as artificial stones or can be transferred elsewhere without any need for keeping them spaced apart from each other. Consequently, at the end of a second processing shift, the blocks produced during the first shift can be removed, releasing the relevant deposit zone 140 for a third shift .

The rotary formwork 40 described above can have a variable dimension, which is normally between 1 and 2 m. In the case of a formwork having a length equal to approximately 1.5 m, a revolution of the formwork produces blocks of 0.53 m³ taking approximately 2 minutes. If the hopper is filled every four revolutions of the formwork, the overall loading times in an 8-hour shift and the transfer times from one deposit zone 140 to another are less than an hour. In an 8-hour processing shift, there are further produced 100 m³ of blocks.

The above-described plant not only provides artificial stones in an area without natural stones, it also eliminates the need for carrying out a grading of the stones in order to select those with dimensions suitable for the intended use, for example, sufficient to be retained by the mesh of a gabion. The C-shaped blocks obtained with the present

invention are in fact all of predetermined dimensions. It is then known that the machinery 10 for producing the blocks can be readily transported in a container so as to allow the production of the blocks directly at the place of use, where it will be sufficient to provide at least one lifting

carriage and a mixing station, without any need, for example, for any transport belt. Furthermore, as can clearly be seen in Figure 1, it is readily able to be cleaned because only a portion of the moulds 50 are covered with the protection plate 49 while the others are readily accessible. In this manner, for example, it is possible to clean the rotary formwork with a jet of water which is directed towards the uncovered moulds while the formwork is caused to rotate.

Naturally, the principle of the invention remaining the same, the forms of embodiment and details of construction may be varied widely with respect to those described and illustrated, without thereby departing from the scope of the invention .

Claims

1. Machinery (10) for producing artificial stones comprising :

- a hopper (30) which is provided with a lower opening (34), the hopper being capable of containing an admixture of at least cement and water and conveying it through the lower opening (34), and

- a rotary formwork which comprises a rotatable cylindrical member which is provided with a plurality of moulds (50), the rotary formwork (40) being arranged below the hopper (30), so that at least one mould (50) is arranged by the lower opening (34) of the hopper (30) in order to receive the admixture from the hopper,

wherein there are provided on two opposing walls of the hopper (30) two vibrators (36) which are capable of imparting a vibration to the hopper.

2. Machinery (10) according to the preceding claim, wherein two bars (80), to which the two vibrators (36) are fixed, respectively, are fixed to two opposing walls of the hopper (30) .

3. Machinery (10) according to the preceding claim, wherein the two bars have a U-shaped cross-section.

4. Machinery (10) according to any one of the preceding claims, wherein the hopper (30) is provided at the inner side thereof with a rotatable mixer (92) .

5. Machinery (10) according to any one of the preceding claims, wherein the removable moulds (50) can selectively be fixed to the cylindrical member (42) .

6. Machinery (10) according to the preceding claim, wherein each mould comprises a plurality of different mould forms (52), each of which is capable of forming an artificial stone .

7. Machinery (10) according to claim 5 or 6, wherein there are provided between the moulds (50) and the cylindrical member (42) anti-vibration elements (70) .

8. Machinery (10) according to the preceding claim, wherein the anti-vibration elements (70) are disks of shock-absorbent material which are arranged between the moulds and

cylindrical member and through which connection elements (62, 63) which fix the moulds to the cylindrical member extend.

9. Machinery (10) according to the preceding claim, wherein the anti-vibration elements (70) are rubber disks.

10. Machinery (10) according to any one of claims 7 to 9, wherein, at the ends of each mould, there are provided housings (60) for the connection elements (62, 63) with respect to the cylindrical member (42), the housings (60) comprising a base wall (64) in which there are formed holes (66) for the connection elements (62) and an upper wall (68) for protecting the connection elements from the cement.

11. Machinery (10) according to any one of the preceding claims, further provided with wheels for the movement thereof during production.

12. A plant (100) for producing artificial stones,

comprising :

- a mixing station (110) of at least cement and water, - machinery (10) according to any one of the preceding claims .

13. A plant (100) for producing artificial stones according to the preceding claim, wherein the machinery (10) can be moved in a deposit zone (140) .

14. A process for producing artificial stones, comprising the steps of:

- mixing at least cement and water,

- transferring the admixture obtained to a hopper (30),

- imparting a vibration to the hopper by actuating two vibrators (36) which are arranged on two opposite walls of the hopper ( 30 ) ,

- pouring the admixture from an opening (34) of the hopper (30) into at least one mould form of a rotary formwork (40) in order to form at least one artificial stone,

- rotating the rotary formwork in order to unmould, as a result of gravitational force, the at least one artificial stone .

15. A process for producing artificial stones according to the preceding claim, wherein, while the rotary formwork is rotated, at the same time the machinery is moved in order to unmould the at least one artificial stone on the ground.