Title: Scarifier attachment and operating machine comprising such an attachment .

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DESCRIPTION

The present invention concerns a scarifier attachment and an operating machine comprising such an attachment. The invention has been developed with particular reference to "special scarifications" in the construction and infrastructure sector, as defined below. In particular, the invention is intended for the removal of material such as concrete and/or asphalt, preferably along both curvilinear and straight paths.

BACKGROUND ART

In the construction and infrastructure sector it is often necessary to carry out scarification processes, in the sense of material removal. Scarification can have several reasons. For example, it is used for restoring artifacts wherein part of the concrete or asphalt is removed to replace it with new layers. The surface to be restored can be of any type, for example the curved vault of a road tunnel, the kerb of a viaduct, a flat wall of a containment wall, etc. Scarification can also be used to excavate or widen passages, such as road tunnels, rooms within them or the like, railway tunnels and supply channels for water or hydroelectric reservoirs, especially in the presence of hard layers of soil, such as rock.

Scarification can also be used for a demolition purpose, or for cutting material, for example to cut gutters or dig trenches.

Traditional scarification methods involve high- pressure water jets or planers mounted on traditional earth-moving machines or other machines with an operating arm such as the one proposed by the Applicant himself in Italian patent application no. 102021000007049.

In particular, the previous patent application of the Applicant proposes a machine for scarification with a layout comprising a carriage on which an articulated arm is mounted at the distal end of which a cutter is placed.

The previous application was about a process for managing the power of the machine to give continuity and uniformity of work to the cutter.

Thanks to the object of the previous patent application, the power available to the scarifier attachment mounted on the machine can be much higher than that available to a common earth-moving machine, because of which the planers normally available on the market are inadequate.

An example of such planers is given in the previous European patent application No. EP3719209A2 by SIMEX Engeneering srl.

This planer has a rotary cutting attachment mounted cantilevered on a frame for excavation depth adjustment needs. A single motor is coupled to the rotary cutting attachment by means of a coupling flange placed inside the latter (fig. 5 of EP3719209A2). From the field experience made by the Applicant using this type of planer, it appears that its layout is not able to cope with great resistances from the material to be removed, and it is necessary to decrease the excavation depth multiplying the number of passes.

Alongside this there are a number of other defects, such as the fact that the excavated debris can easily damage it. Perhaps the most serious defect, however, is that when excavating concrete the reinforcing bars twist around the rotation axis and are dragged inside the rotary cutting attachment in the area of coupling to the motor. The consequence is a serious damage to the motor, starting with the oil seal elements. Furthermore, in this position the twisted bars cannot be easily removed and require a complete disassembly of the attachment, with consequent stoppage of the work.

In the patent literature DE2620362; 2518217, US5315770 are also known.

Aim of the present invention is to overcome all, or some, of the drawbacks of the prior art.

In particular, a preferred aim of the present invention is to provide an attachment with low needs for stopping for restoration, in particular for penetration of debris and/or concrete bars twisted around the rotor, and/or which allows an easy and fast restoration when necessary.

A further aim of the present invention is to provide an attachment protected against the penetration of the excavated debris and bars and which at the same time allows the use of very high hydraulic powers for a high productivity.

A further aim of the present invention is to provide an easy and inexpensive machine.

GENERAL INTRODUCTION

According to a first general aspect thereof, the present invention concerns a scarifier attachment (20) comprising at least one arm (38, 39) placed to support a cutter (40) rotatably around a rotation axis (Y), characterized in that said arm (38, 39) supports receiving and guide means (92) of any bars that the cutter (40) finds in the concrete during the excavation and that it drags along with it, wherein the receiving and guide means (92) are arranged laterally to the cutter with reference to the axial direction. This advantageously allows the exposed bars to be kept visible for easy removal, for example by cutting with a grinder, preventing them from getting stuck between the shaft and the cutter, for example damaging the motor or other parts or simply forcing a disassembly for their removal.

Preferably between the receiving and guide means (92) and the cutter there is an interspace (100), arranged to generate a distance Z in the axial direction.

According to some preferred embodiments, the receiving and guide means (100) comprise at least one guide surface (93) of the bars with an inclination with respect to the rotation axis (Y) such as to guide said bars away from the cutter (40).

For example, said inclination is such that said guide surface (110) has a first portion axially distal from said cutter and radially proximal to said axis Y, and a second portion axially proximal from said cutter and radially distal from said axis Y.

According to some preferred embodiments, the receiving and guide means (92) comprise at least one rod integral with one of said arms (38, 39) so as to be protruding in a direction inclined with respect to the rotation axis (Y), wherein said rod has a joining point to said arm proximal to said axis, and an end opposite to the affixing point that is free and distal from said axis (Y).

According to a preferred general feature, the attachment comprises rotatable coupling means (50, 52) interposed between said arm (38, 39) and the cutter so as to define an interspace (90) between them and the cutter in the radial direction, wherein said receiving and guide means (92) are placed at least partially radially above said radial interspace (90) and at least partially laterally thereto in the axial direction (Y). This advantageously creates a path that is difficult to access for the concrete bars that may be extracted from the cutter during the excavation.

According to some preferred embodiments said rotatable coupling means (52) are contained in a cavity (47a, 47b) of the cutter, while said receiving and guide means (92) are lateral thereto.

Preferably, said receiving and guide means (92) have a maximum radial extension flush with the maximum outer diameter of the cutter or smaller than it. Preferably the cutter (40) is supported near both its axial ends by respective two arms (38, 39) wherein between each of the arms and the cutter there are the features of said respective claims.

According to a preferred general feature of the invention, the cutter comprises a hollow cylindrical body (42) with an outer cylindrical surface (44) with a diameter greater than or equal to 400 mm, for example greater than or equal to 450 mm, preferably equal to 478 mm, wherein the cylindrical body comprises at least a central area with thickness greater than or equal to 50 mm, for example greater than or equal to 60mm, preferably greater than or equal to 70mm, for example equal to 74mm.

This advantageously creates a flywheel effect that allows to regulate the operation when the cutter encounters resistance variations in the excavated material, such as the presence of concrete bars.

According to a second general aspect thereof, the invention concerns an operating machine for scarification comprising an undercarriage (5), a carriage (10) and coupling means rotatable (12) between them around a vertical axis (X), wherein:

- the carriage supports an arm (15) at the distal end of which a scarifier attachment (20) is placed; wherein the arm (15) is movable above the carriage (10) so as to rotate in a vertical plane between a lowered operating position, and a raised operating position; characterized in that the scarifier attachment is of the type described above. DETAILED DESCRIPTION

Further characteristics and advantages of the present invention will become clearer from the following detailed description of the preferred embodiments thereof, with reference to the appended drawings and provided by way of indicative and non-limiting example. In such drawings:

- Figure 1 shows, in side view, a machine for scarification with an arm on which a scarifier attachment is mounted according to the present invention;

- Figure 2 shows the machine of Figure 1 in perspective view with the arm raised;

- Figure 3 shows the scarifier attachment of the previous figures in a front view;

- Figure 4 shows the scarifier attachment of Figure 3 in section according to a plane passing through the rotation axis of the cutter;

- Figure 5 shows an enlarged scale detail of the coupling area between cutter and motor of Figure 4;

- Figure 6 shows an enlarged scale detail of the coupling area between bearing and cutter of Figure 4;

- Figure 7 shows an enlarged scale detail of Figure 3.

With reference to Figure 1, a machine for scarification according to the present invention is shown, indicated as a whole with the reference number 1.

In the following vertical and horizontal will conventionally indicate the traditional directions with respect to the ground.

The machine 1 is as a whole a vehicle equipped with an undercarriage 5 movable with respect to the ground, on which a carriage 10 is rotatably mounted, around a vertical axis X. The latter supports and drags into rotation along with it an operating arm 15 and a scarifier attachment 20 placed at the distal end of said arm .

The operating arm 15 is preferably coupled to the carriage 10 movably above it, around a pin 35 with horizontal axis Y'. In particular, the arm 15 is rotatable in a vertical plane between a lowered operating position, and a raised operating position.

Referring to Figures 3 and 4, the scarifier attachment 20 comprises a frame 30 and a cutter 40 supported rotatably by said frame.

The frame 30 comprises a coupling portion 32 for coupling to the operating arm 15, and a fork 34 for coupling to the cutter 40.

The frame 30 can for example be made in two parts 36 and 37, each comprising a respective arm 38 and 39 of the fork, preferably joined together in a separable manner, for example by means of bolts.

The cutter 40 is supported by both arms 38 and 39 of the fork, rotatably with respect to them about an axis Y.

The mounting of the scarifier attachment 20 on the operating arm 15 is such that preferably the axes Y and Y' are parallel, so that the axis Y is preferably horizontal.

A cutter is generally a rotary cutting attachment that removes the material in a direction perpendicular to its own rotation axis Y.

For this reason, the cutter 40 has a substantially cylindrical body 42 with a substantially cylindrical outer surface 44 coaxial to the axis Y and provided with a plurality of knives 46.

The cylindrical body 42 has a cavity 47a and 47b at least at each axial end, and preferably cylindrical. Preferably said end cavities 47a and 47b are part of a single cavity 47 that axially crosses the cylindrical body 42.

The cylindrical body 42 is supported near both its axial ends by the respective arms 38 and 39 of the fork, by interposition of respective rotatable coupling means 50 and 52, wherein said rotatable coupling means 50 and 52 are at least partially housed within said respective end cylindrical cavities 47a and 47b.

With reference to Figures 5 and 6 and the rotation axis Y, the rotatable coupling means 50 and 52 each comprise a first body 54, 55 and a second body 64, 65 which are rotatable with respect to each other about the axis Y.

The first body 54, 55 serves as a shield of the respective end cylindrical cavity 47a, 47b and for this reason it is cylindrical in shape. It is fixed with respect to the fork 34 and coaxial to the cutter 40.

Each shielding body 54 and 55 has an outer cylindrical surface at least partially radially facing a corresponding inner cylindrical end surface of the cutter 58 and 59. Said inner cylindrical surfaces are surfaces of said end cylindrical cavities 47a and 47b.

The outer and inner cylindrical surfaces are separated by an interspace 90 given by a distance in the radial direction D less than or equal to 10 mm, wherein 3 mm or 4 mm or 5 mm are preferred values. In general, any revolution surface around the axis Y can be replaced at said cylindrical surfaces.

Preferably each shielding body 54, 55 is coupled to the respective fork arm 38 and 39 in the axial direction (with reference to the axis Y).

Each second body 64 to 65 is fixedly coupled to the cylindrical body 40 inside the respective end cavity 47a and 47b.

As visible in Figure 5, according to a preferred example the first coupling means 50 comprise a motor, preferably hydraulic, wherein the shielding body 54 comprises the motor housing and wherein the corresponding second body 64 comprises the motor shaft.

The shaft 64 in particular is coupled within the cavity 47a by means of a radial flange 74.

As visible in Figure 6, according to a preferred example the second coupling means 52 comprise a bearing 80, preferably an oscillating bearing with a radially outer fifth wheel 82 and a radially inner fifth wheel 84, wherein the shielding body 55 comprises or provides a seat for the outer fifth wheel 82, and wherein the corresponding second body 65 comprises or provides a seat for the inner fifth wheel 84. The inner fifth wheel 84 in particular is coupled inside the cavity 47b by means of a pin 70 axially protruding from a radial flange 72 fixed in said cavity. Said pin 70 is a seat of the inner fifth wheel 84 of the bearing, and can be inserted and extracted from it in an axial direction.

To allow the cutter 40 to be mounted to the fork 34, the pin 70 is integral with the cylindrical body 42 and the arms 38 and 39 of the fork can be joined and separated from each other by means of an approach and distancing movement in the axial direction.

In this way, the mounting process allows the motor 50 to be fixed inside the cavity 47a of the cylindrical body 42 and to the arm 38.

At the opposite cavity 47b the bearing 52 is coupled to the arm 39 and inserted into the pin 70 bringing the two arms 38 and 39 closer in the axial direction, so as to close the motor 50, the cylindrical body 42 and the bearing 52 like a package between the two arms 38 and 39.

According to a possible variant the outer fifth wheel is coupled to the cylindrical body and the inner fifth wheel to the arm 39.

According to a possible variant both coupling means 50 and 52 are motors and the cylindrical body 30 is preferably divided into two parts which are rotatable with respect to each other, each put into rotation by one of the two motors.

Preferably the cavities 47a and 47b are cylindrical seats that constitute an enlargement of the through cavity 47, whereby they form respective steps with respect to it, useful to provide an axial stop for coupling the second bodies 64 and 65.

Preferably the cylindrical body 42 has an outer cylindrical surface 44 with a diameter greater than or equal to 400 mm, for example greater than or equal to 450 mm, preferably equal to 478 mm, wherein the cylindrical body comprises at least a minimum inner diameter less than or equal to 350mm, preferably less than or equal to 330mm. The cylindrical body, for example, comprises a radial section, for example in a central area, with thickness greater than or equal to 50 mm, for example greater than equal to 60 mm, preferably greater than or equal to 70 mm, for example equal to 74 mm. The cylindrical body 42 preferably has a length in the direction of its rotation axis greater than or equal to 1000mm, for example greater than or equal to 1200mm. The cutter is made of metal material, for example steel.

Referring now to Figure 7, it can be noted that each of the fork arms 38 and 39 supports protection means 92 of the interspace 90 having the function of intercepting any reinforcing bars that the cutter drags along with it twisting them on the sides of the cylindrical body 42. Said protection means 92 comprise one or more interception elements for each arm 38 and 39 supported interposed between said arms and the cylindrical body 42, in sliding contact with the latter or with a second interspace 100 of separation between them, preferably arranged to generate a distance Z in the axial direction.

The distance Z is preferably less than or equal to 2 mm, more preferably 1 mm.

The protection means 92 preferably comprise at least one guide surface 93 of the intercepted bars with an inclination with respect to the rotation axis Y such as to guide said bars away from the cutter 40.

Preferably, the protection means 92 comprise at least one rod affixed to a relative fork arm 38, 39 in a direction inclined with respect to the rotation axis Y, wherein the affixing point is proximal to said axis, and the opposite end is distal.

In use, the cutter 40 sets considerable amounts of debris in motion and when it encounters reinforcing bars embedded in the concrete, drags them into rotation.

The coupling scheme of the cutter through the two interspaces 90 offers a function of protection against debris and especially against bars. In fact, the latter are kept outside the cutter, where they twist in an exposed and visible way and can easily be reached by an operator to be cut, for example with a grinder, and removed.

Thanks to this coupling and protection scheme, the cutter is able to take advantage of higher powers and excavation depths.

In addition or alternatively, also the protection means 92 intercept the bars and provide them with a seat around which to twist and remain exposed and visible for removal.

It is noted that, the presence of the protection means 92 is also applicable to frames that support the cutter on one side only, cantilevered from a single arm, such a possible variant is not illustrated.

A further advantage of use is the aspect of the thickness of the cylindrical body, which, being very high allows to regulate the operation in the face of greater resistances encountered, especially when it encounters said reinforced concrete bars. The hydraulic system that normally supplies the power to the cutter by means of the hydraulic motor, thus benefits therefrom and has a consequent reduction in faults.

GENERAL INTERPRETATION OF THE TERMS

In understanding the object of the present invention, the term "comprising" and its derivatives, as used herein, are intended as open-ended terms that specify the presence of declared characteristics, elements, components, groups, integers and/or steps, but do not exclude the presence of other undeclared characteristics, elements, components, groups, integers and/or steps. The above also applies to words, which have similar meanings, such as the terms "comprised", "have" and their derivatives. Furthermore, the terms "part", "section", "portion", "member" or "element" when used in the singular can have the double meaning of a single part or a plurality of parts. As used herein to describe the above executive embodiment (s), the following directional terms "forward", "backward", "above", "under", "vertical", "horizontal", "below" and "transverse", as well as any other similar directional term, refers to the embodiment described in the operating position. Finally, terms of degree, such as "substantially", "about" and "approximately", as used herein, are intended as a reasonable amount of deviation of the modified term such that the final result is not significantly changed.

While only selected embodiments have been chosen to illustrate the present invention, it will be apparent from this description to those skilled in the art that various modifications and variations can be made without departing from the scope of the invention as defined in the appended claims. For example, the size, shape, position or orientation of the various components can be modified as needed and/or desired. The components shown directly connected or in contact with each other can have intermediate structures arranged between them. The functions of one element can be performed by two and vice versa. The structures and functions of one embodiment can be adopted in another embodiment. All the advantages of a particular embodiment do not necessarily have to be present at the same time. Any characteristic that is original compared to the prior art, alone or in combination with other characteristics, should also be considered a separate description of further inventions by the Applicant, including the structural and/or functional concepts embodied by such characteristics. Therefore, the foregoing descriptions of the embodiments according to the present invention are provided for illustrative purposes only and not for the purpose of limiting the invention as defined by the appended claims and the equivalents thereof.