TECHNICAL FIELD

The present invention relates in general to the field of high-pressure water jet cleaning machines and, more particularly, to an accessory adapted to be connected to high-pres sure water jet cleaning machines in order to increase their field of application.

PRIOR ART

As is well known, a high-pressure water jet cleaning machine is a device adapted to cre ate a high-pressure jet of water through which it is possible to remove dirt and/or encrus tations from many solid surfaces, such as floors, walls, windows, car bodies and so on. The high-pressure water jet cleaning machine is essentially composed of a high-pressure pump that, driven by a motor, such as an electric motor, sends high-pressure water through a delivery lance, to a nozzle that delivers the fluid.

A plurality of accessories may generally be connected to the high-pressure water jet cleaning machine, including for example a cleaning head with a brush, for cleaning sur faces by means of the action of the pressured jet and the bristles of the brush.

In particular, this accessory comprises delivery nozzles adapted to deliver fluid in a sub stantially orthogonal direction to the surface to be treated, which allows cleaning opera tions to be carried out effectively.

However, a drawback associated with such accessories of the known type is that the delivered fluid and the removed dirt remain deposited on the surface.

In particular, in the case of flat surfaces without discharge inclinations, subsequent oper ations are necessary to sweep away the fluid delivered and the dirt removed from the surfaces.

A need felt in the sector is, therefore, that of having available an accessory that is able to completely remove the dirt, sweeping away the residues (deposited after treatment with the high-pressure water jet cleaning machine) and leaving the surface completely clean and without liquid residues.

An object of the present invention is to meet this and other needs, within a simple, rational and economically advantageous solution.

Such object is achieved by the features of the invention indicated in the independent claims. The dependent claims outline preferred and/or particularly advantageous aspects of the invention. DISCLOSURE OF THE INVENTION

The invention, particularly, makes available an accessory for high-pressure water jet cleaning machines provided with a delivery lance comprising:

- a box-shaped body provided with an opening;

- a cleaning brush connected to said box-shaped body;

- a delivery nozzle fixed to said box-shaped body and oriented such to deliver a pressured liquid through the opening of the box-shaped body; and

- a connection assembly comprising a first tract rigidly connected to the delivery nozzle, a second tract connected to the first tract by means of a joint, and a hy draulic connector, in fluid communication with the delivery nozzle and rigidly fixed to the second tract, adapted to removably enable fitting the delivery lance to the connection assembly, wherein the joint is configured to allow a variation of the relative position of the first tract with respect to the second tract.

Thanks to this solution the accessory allows to clean the surfaces with a jet perpendicular to the surface and then allows the user to tilt the accessory to sweep the surface with a tilted pressured liquid jet of fluid.

In particular, by varying the relative position of the first tract (to which the delivery nozzle is rigidly connected) with respect to the second tract (adapted to be connected to the delivery lance), it is possible to vary the inclination of the delivery lance with respect to the accessory.

One aspect of the invention, in particular, provides that the joint may define a hinge axis with respect to which the first tract and the second tract can rotate between each other, and can be configured to allow the relative positioning and blocking of the first tract and of the second tract in at least a first relative position and a second relative position angu larly spaced from each other.

This solution makes it possible to block the first tract and the second tract in a desired position. In particular, the at least two positions in which the relative positioning of the first tract and the second tract is ensured are adapted to allow a dual function of the accessory for the high-pressure water jet cleaning machine.

Even more in detail, the delivery nozzle may be positioned so as to operate in a different manner depending on the position assumed by the first tract (rigidly connected thereto), i.e., it may assume at least one position in which it sweeps away the deposited dirt and the delivered fluid.

A further aspect of the invention provides that in the first relative position a longitudinal axis of the first tract and a longitudinal axis of the second tract may be parallel between each other and in the second operative position can be tilted between each other.

One aspect of the invention further provides that the joint may comprise a first portion rigidly fixed to the first tract and a second portion rigidly fixed to the second tract and hinged to the first tract with respect to the hinge axis of the joint.

In this way the joint can make the first tract and the second tract integral with each other, allowing a simple reciprocal positioning and blocking of said tracts in a desired position. According to an aspect of the invention, further, the first tract, the second tract and the joint may be hollow inside, and the hydraulic connector may be in fluid communication with the delivery nozzle by means of the first tract, the second tract and the joint.

Thanks to this solution, the connection assembly is shaped so as to allow the delivery nozzle to deliver pressured liquid by means of the (indirect) fluid communication with the delivery gun/lance.

According to a further aspect of the invention the first tract and the first portion are made in a single piece and the second tract and the second portion are made in a single piece. In a further aspect of the invention, it is provided that the accessory for high-pressure water jet cleaning machines may comprise an element contacting the ground associated with the box-shaped body and comprising at least one of a low-friction coefficient slide and a rolling body rotatably associated to the box-shaped body.

Thanks to the presence of said element contacting the ground, it is possible to easily move the accessory for high-pressure water jet cleaning machines, in particular when the joint allows the blocking of the first tract and of the second tract in a particular relative position.

In detail, in at least one relative position, the first tract may be positioned with respect to the second tract so as to allow a suitable (desired) inclination of the delivery lance to which the accessory is connected.

The element contacting the ground allows, therefore, to easily support and move the box shaped body of the accessory for high-pressure water jet cleaning machines, in particular when said box-shaped body is tilted according to the inclination of the delivery lance. According to a further aspect of the invention, then, the cleaning brush may comprise a plurality of bristles protruding from a lower portion of the box-shaped body in a direction moving away from said box-shaped body and wherein the element contacting the ground protrudes from the box-shaped body in a direction moving away from said box-shaped body.

Thanks to the presence of the bristles, the accessory for high-pressure water jet cleaning machines allows a high cleaning effect through the pressure exerted by the bristles on the surface to be treated.

In particular, the action of the bristles with which the cleaning brush is provided allows to exert a rubbing action on the surface to be treated in order to increase the effectiveness of cleaning and washing, removing dirt and/or encrustations that are difficult to remove using only the pressured fluid delivered.

A further aspect of the invention further provides that the accessory for high-pressure water jet cleaning machines may comprise a tank, adapted to contain a second fluid, housed in the box-shaped body.

In this way, a special tank is made available in which to insert a second fluid, for example a detergent, adapted to be delivered in order to optimize the cleaning action of the acces sory for high-pressure water jet cleaning machines.

Furthermore, according to a further aspect of the invention, the accessory for high-pres sure water jet cleaning machines may further comprise an adjustment device connected to the tank, adapted to partialize the flow rate of a second fluid to be delivered.

Thus, a device is made available to deliver a desired flow rate of a second fluid.

In particular, said device may be operable between an opening configuration correspond ing to a maximum flow rate of a second fluid to be delivered, a closing configuration cor responding to a null flow rate of a second fluid to be delivered, and a plurality of interme diate configurations corresponding to a plurality of different flow rates of a second fluid to be delivered.

Thanks to this solution, by reducing the flow rate of a second fluid (e.g. detergent) to be delivered, it is possible to guarantee an efficient cleaning of the surface to be treated, avoiding waste in ecological and economic terms.

A further aspect of the invention further makes available a cleaning assembly comprising: - a high-pressure water jet cleaning machine provided with a delivery lance; - an accessory as described above, adapted to be connected to the delivery lance of the high-pressure water jet cleaning machine.

Such a solution allows to achieve the purposes described above for said cleaning assem bly.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention will be more apparent after reading the following description provided by way of non-limiting example, with the aid of the accom panying drawings.

Figure 1 is an axonometric view of an accessory for high-pressure water jet cleaning machines according to the invention.

Figure 2 is a front view of the accessory for high-pressure water jet cleaning machines of Figure 1 .

Figure 3 is a section view according to the plane Ill-Ill of figure 2.

Figure 4 is a side view of the accessory for high-pressure water jet cleaning machines of Figure 2.

Figure 5 is a section view according to the plane V-V of figure 4.

Figure 6 is a section view according to the plane VI-VI of figure 4.

Figure 7 is a bottom view of the accessory for high-pressure water jet cleaning machines of Figure 2.

Figure 8 is a section view according to the plane VIII-VIII of figure 7.

Figure 9 is an exploded view of the accessory for high-pressure water jet cleaning ma chines according to the invention.

BEST MODE FOR IMPLEMENTING THE INVENTION

With particular reference to such figures, an accessory for high-pressure water jet clean ing machines used to clean solid surfaces, for example large floors, has been globally indicated by 10.

A high-pressure water jet cleaning machine, which is not illustrated because it is known per se, comprises a high pressure pump, e.g. a piston pump, and a motor, e.g. an electric motor adapted to drive the pump so as to enable the latter to pump a fluid, e.g. water, to a delivery gun.

Said delivery gun may comprise, as is known, a valve apparatus adapted to be manually operated, for example by means of a trigger, to selectively allow or prevent the passage of fluid.

The high-pressure water jet cleaning machine is also provided with a delivery lance, which can be removably connected to the delivery gun.

Said accessory 10 for high-pressure water jet cleaning machines comprises a box shaped body 20 defining within it a cavity and is provided with an opening 21 , through which the cavity communicates with the outside.

In particular, the box-shaped body 20 may comprise a perimeter, i.e., tubular, side wall defining the opening 21 . That is, the perimeter side wall has a lower perimeter edge 22, for example closed in a ring, of the box-shaped body 20 that defines/delimits the opening 21.

In the illustrated embodiment, the perimeter side wall comprises at least four vertical side walls 23 seamlessly connected to an upper portion 24 and protruding in a direction mov ing away from said upper portion 24 towards the surface to be treated. In particular, the vertical side walls 23 comprise at least one pair of short side walls and one pair of long side walls, adapted to define a substantially rectangular profile of the entire box-shaped body 20.

The box-shaped body 20 is closed superiorly, i.e. on the opposite side with respect to the opening 21 by said upper portion 24 of said box-shaped body.

On the upper portion 24 of the box-shaped body 20 there is, moreover, obtained an upper opening 25 adapted to put the cavity of the box-shaped body 20 in communication with the outside of the box-shaped body 20.

Said box-shaped body 20 may be made of plastic material and obtained, for example, by injection molding.

However, it is not excluded that, in further embodiments, the profile of the box-shaped body 20 may be, for example, substantially circular or polygonal in shape and/or that the box-shaped body may be made of any (different) material.

It should be noted that, in the present discussion, a lower perimeter edge 22 means an edge of the box-shaped body 20 facing downward, i.e., toward the surface to be treated, in use.

The accessory 10 for high-pressure water jet cleaning machines further comprises at least one delivery nozzle 30 configured to deliver pressured fluid at the surface to be treated. In detail, said delivery nozzle 30 is fixed, that is, rigidly connected (directly or indirectly) without residual degrees of freedom, to the box-shaped body 20.

The delivery nozzle 30 is positioned in the cavity of the box-shaped body 20 so as to deliver pressured fluid through the opening 21 of the box-shaped body 20.

In particular, the delivery nozzle 30 is oriented such to deliver pressured fluid along a delivery direction E substantially orthogonal to the opening 21 , that is substantially or thogonal to a lying plane of the opening 21 , or again substantially orthogonal to a lying plane of the lower perimeter edge 22. Substantially orthogonal means tilted at an angle comprised between +/- 5° with respect to an orthogonal, preferably orthogonal, axis.

In detail, the accessory 10 comprises a supply conduit 31 to which the delivery nozzle 30 is connected, which supply conduit 31 is fixed to the box-shaped body 20.

Said supply conduit 31 is thus rigidly connected without residual degrees of freedom to the box-shaped body 20.

The supply conduit 31 , within which the fluid to be delivered is supplied, is shaped and is fixed to the box-shaped body 20 such that the delivery nozzle 30 delivers fluid in a direc tion substantially orthogonal to the opening 21 , or orthogonal to a lying plane of the open ing 21 , or again orthogonal to a lying plane of the lower perimeter edge 22.

In the embodiment shown in the figures, the accessory 10 comprises a plurality of delivery nozzles 30, for example, three in number.

The supply conduit 31 comprises an inlet port 311 and at least one outlet port 312 to which the delivery nozzle 30 is connected.

At the inlet port 311 , the supply conduit 31 has a hydraulic connector 32.

The supply conduit 31 protrudes externally from the box-shaped body 20 through the upper opening 25 such that the inlet port 311 is external to the box-shaped body 20.

The supply conduit 31 is shaped so that a first tract thereof at the inlet port 311 and a second tract thereof at the outlet port 312, i.e., at the delivery nozzle 30, are tilted between each other (in particular with respect to a plane of vertical section) by an angle comprised between 30° and 50°, preferably comprised between 35° and 45°.

Each delivery nozzle 30 includes an internally hollow body 300 provided with an inlet port 301 and an outlet port (or orifice) 302, and defining in its inside a conduit adapted to put said inlet port 301 in communication with said outlet port 302.

The accessory 10 for high-pressure water jet cleaning machines further comprises a cleaning brush 40, connected to the box-shaped body 20, configured to directly contact the surface to be treated in order to perform a mechanical dirt removal action.

Said cleaning brush 40 surrounds the opening 21 , is for example connected to the box shaped body 20 along the lower perimeter edge 22 and protrudes interiorly from the box shaped body 20 in the direction moving away therefrom.

The cleaning brush 40 may comprise a plurality of bristles 41 supported at the lower pe rimeter edge 22 of the box-shaped body 20 and protruding in a direction moving away from said lower perimeter edge 22 towards the surface to be treated, for example along respective directions substantially parallel to the fluid delivery direction defined by the delivery nozzle 30.

In the embodiment shown in the figures, the bristles 41 with which the cleaning brush 40 is provided entirely delimit the lower perimeter edge 22, following the profile defined by it. When the accessory 10 rests on the ground, the box-shaped body 20 contacts the ground at least by means of the cleaning brush 40, or at least part of the cleaning brush 40. Preferably, the ends of the bristles distal from the box-shaped body lie substantially in a plane, which plane is substantially orthogonal to the delivery direction E of the nozzle, i.e., the nozzles 30.

When all of the bristles contact the surface to be cleaned, the ends of said bristles sub stantially lie in a plane parallel to a lying plane of the surface to be cleaned.

The accessory 10 for high-pressure water jet cleaning machines further comprises at least one element contacting the ground associated to the box-shaped body 20, adapted to allow the support and/or the movement of said box-shaped body 20.

Said element contacting the ground may be, for example, a rigid slide made of a low- friction coefficient material or any rolling body rotatably associated to the box-shaped body 20, for example a wheel, a ball or a roller.

When the accessory 10 rests on the ground, the box-shaped body 20 contacts the ground only by means of the cleaning brush 40 and the contact element.

The contact element protrudes from the box-shaped body 20 in a direction moving away therefrom so that it is substantially tangent to a lying plane of an end of the cleaning brush

40 distal from the box-shaped body 20, i.e., a lying plane of the free ends of the bristles

41 of the cleaning brush 40. Said element contacting the ground is associated to the box-shaped body 20 in an exter nal position with respect to the opening 21 and for example also external with respect to the cleaning brush 40.

In the embodiment shown in the figures, the accessory 10 for high-pressure cleaning machines comprises a pair of wheels 50, for example the element contacting the ground comprises only two wheels 50, each of which is rotatably idly associated to the box shaped body 20 with respect to a rotation axis that, when the accessory is in use, lies on a horizontal plane.

Said rotation axes are eccentric, i.e., skewed, with respect to the direction of the flow delivered by the delivery nozzle 30, or the flow delivered by the plurality of delivery noz zles.

Even more in detail, the rotation axes of the wheels 50 lie on a vertical plane which is parallel to a vertical plane on which the delivery direction of the delivery nozzles 30 lies and which is distanced by a non-null quantity from said vertical plane.

The accessory 10 for high-pressure water jet cleaning machines comprises, in particular, a connection assembly 60 adapted to be interposed between the delivery lance and the at least one delivery nozzle 30.

In particular, said connection assembly 60 is adapted to be rigidly fixed to the at least one delivery nozzle 30, i.e. to the supply conduit 31 , and to be removably fitted to the delivery lance.

The connection assembly 60 comprises a first tract 61 rigidly connected (directly or indi rectly) to the at least one delivery nozzle 30, for example that develops along a longitudi nal axis X1 .

In the embodiment shown in the figures, the first tract 61 is rigidly and directly connected, that is, connected without residual degrees of freedom, to the supply conduit 31 to which the delivery nozzles 30 are connected.

In greater detail, the first tract 61 of the connection assembly 60 is rigidly and directly connected to the inlet port 311 of the supply conduit 31 , that is to the hydraulic connector 32.

Said first tract 61 includes an inlet port 611 , the primary function of which will be better specified below, and an outlet portion provided with an outlet port 612 connected to the supply conduit 31 . In detail, the first tract 61 is hollow inside and defines in its inside a fluid passageway 613 connecting the inlet port 611 to the outlet port 612 and that develops along the longitudinal axis X1 of the first tract 61 .

For example, in the connection between hydraulic connector 32 and first tract 61 , the inlet port 611 defines a "female" portion and a head portion 321 of connector 32, (which hy draulic connector 32 is in fluid communication with delivery nozzles 30 at the portion con strained to the supply conduit 31 ) defines a "male" portion.

Said hydraulic connector 32, preferably with a quick coupling and release, when inserted and blocked in the cavity defined by the "female" portion of the first tract 61 , puts the delivery nozzles 30 in fluid communication with the first tract 61 .

Said hydraulic connection between hydraulic connector 32 and first tract 61 can be made hermetic with respect to the surrounding environment by means of a gasket 614, for ex ample an annular gasket, which is coaxially threaded and blocked on the head portion 321 of the hydraulic connector 32, so as to be radially compressed between an external surface of said hydraulic connector 32 and a corresponding internal surface of the cavity of the first tract 61 .

The blocking of the head portion 321 of the hydraulic connector 32 relative to the outlet portion of the first tract 61 may be achieved by means of an automatic snap-on system 615.

For example, such an automatic snap-on system 615 may comprise a movable pawl 616, which is associated to the first tract 61 so as to be able to move in a transverse direction with respect to the direction of insertion of the hydraulic connector 32, a spring 617 adapted to push said pawl 616 towards an extracted position in which it protrudes at least partially inside the cavity of the first tract 61 , and a release button 618 placed on an ex ternal side of the first tract 61 and adapted to be manually pressed to move the pawl 616, in contrast with the action of the spring 617, towards a retracted position in which it does not protrude into the cavity of the first tract 61 .

Contextually, the head portion 321 of the hydraulic connector 32 may comprise a tapered end tract whose outer surface is adapted to act as a cam profile for transforming the axial movement of insertion of the hydraulic connector 32 in the first tract 61 into a transverse movement of the pawl 616 towards the retracted position, and an annular cavity adapted to face and transversely align with the pawl 616 when the hydraulic connector 32 reaches the blocking position.

In this way, when the blocking position is reached, the pawl 616 pushed by the spring 617 snaps back into its extracted position, engaging the annular cavity and preventing the hydraulic connector 32 from being able to pull out with respect to the first tract 61 .

The connection assembly 60 further comprises a second tract 62, connected to the first tract 61 , and a hydraulic connector 63 rigidly fixed to the second tract 62, for example without residual degrees of freedom, and adapted allow said second tract 62 to be re movable fitted to the delivery lance.

Said second tract 62 develops primarily along a longitudinal axis X2.

The hydraulic connector 63, connected to the delivery lance and to the second tract 62 (connected to the first tract 61 ), is in fluid communication with the delivery nozzles 30.

In the embodiment illustrated in the figures, the second tract 62 is hollow inside and de fines in its inside a conduit 623 for the passage of fluid provided with an inlet port 621 directly in fluid communication with the hydraulic connector 63, and with an outlet port 622 in fluid communication with the inlet port 611 of the first tract 61. Preferably, the conduit 623 of the second tract 62 develops along the longitudinal axis X2.

For example, said longitudinal axis X2 is parallel to a lying plane of the longitudinal axis X1.

The connection assembly 60 includes a joint 64 connecting the first tract 61 to the second tract 62.

Furthermore, the joint 64 is configured to allow a variation of the relative position of the first tract 61 with respect to the second tract 62.

In particular, the joint 64 defines a hinge axis C, and the first tract 61 rotates with respect to the second tract 62 around said hinge axis C.

Said hinge axis C is tilted, for example orthogonal, with respect to the lying plane of the longitudinal axis X1 of the first tract 61 and of the longitudinal axis X2 of the second tract 62.

The joint 64 further comprises releasable blocking means adapted to block the relative position of the first tract 61 and the second tract 62 in at least a first relative position and a second relative position angularly spaced from each other. In the illustrated embodi ment, the releasable blocking means are configured to block the relative position of the first tract 61 and the second tract 62 only in the first relative position and in the second relative position.

In the first relative position, the first tract 61 and the second tract 62, i.e., the longitudinal axis X1 and the longitudinal axis X2, are tilted between each other at different angles with respect to the second relative position.

In particular, in the first relative position, the first tract 61 and the second tract 62, i.e., the longitudinal axis X1 and the longitudinal axis X2, are parallel to each other, i.e., lie on the same plane, and in the second relative position are tilted between each other, for example by an angle comprised between 60° and 80°, preferably between 65° and 75°.

Further, in the first relative position, the second tract 62, i.e., its longitudinal axis X2, is tilted with respect to the fluid delivery direction E of the delivery nozzle 30, i.e., the delivery nozzles 30, by an angle comprised between 30° and 50°, in the second relative position, the second tract 62 is tilted with respect to the fluid delivery direction E of the delivery nozzle 30 by an angle comprised between 30° and 40°, and in passing from the first relative position to the second relative position, the second tract 62, i.e., its longitudinal axis X2, passes through a position (in which it cannot be blocked) in which it is parallel to the delivery direction E.

In particular, in the passage from the first relative position to the second relative position, the second tract 62, that is, the respective longitudinal axis X2, completes a rotation around the hinge axis C comprised between 60° and 90°.

In further detail, in the first relative position, the second tract 62 is turned backwards, i.e., in a direction opposite to a direction of advancement of the accessory when it is in use, and in the second relative position, the second tract 62 is turned forward, i.e., in the di rection of advancement of the accessory.

In the illustrated embodiment, the joint 64 is axially hollow and puts the inlet port 611 of the first tract 61 in fluid communication with the outlet port 622 of the second tract 62. In particular, the joint 64 defines in its inside a fluid passage conduit 643 that connects the inlet port 611 of the first tract 61 to the outlet port 622 of the second tract 62.

In an embodiment not shown, the connection assembly 60 may comprise a flexible hose, for example made of rubber, fluidically connecting the hydraulic connector 63 to the sup ply conduit 31 .

The first tract 61 , the second tract 62 and the joint 64 are, therefore, hollow inside and defining within them fluid passage conduits that altogether form a single conduit that puts the hydraulic connector 63 in fluid communication with the supply conduit 31 .

In this way, therefore, the hydraulic connector 63 (adapted to be connected to the delivery lance) is in fluid communication with the delivery nozzles 30 by means of (at least) the second tract 62, the joint 64 and the first tract 61 .

Said joint 64 further comprises an inlet port 641 in direct fluid communication with the outlet port 622 of the second tract 62, and an outlet port 642 in direct fluid communication with the inlet port 611 of the first tract 61 .

The conduit 643 connects the inlet port 641 to the outlet port 642 along the hinge axis C. In detail, the joint 64 comprises a first portion 644 in which the outlet port 642 is made, rigidly fixed to the first tract 61 , and a second portion 645 in which the inlet port 641 is made, rigidly fixed to the second tract 62 and hinged to the first tract 61 with respect to the hinge axis C of the joint 64.

For example, the first portion 644 comprises a cylindrical body axially traversed by the conduit 643, which is inserted to size into a cylindrical seat made in the second portion 645 provided with a cylindrical inner surface coaxial to the hinge axis C.

Said hydraulic connection between first portion 644 and second portion 645 of the joint 64 is made hermetic with respect to the surrounding environment by means of a plurality of gaskets 646, for example annular gaskets, coaxially blocked between the first portion 644 and the second portion 645, i.e., between the cylindrical body of the first portion 644 and the cylindrical seat of the second portion 645, so as to be radially compressed.

The releasable blocking means comprise a first housing hole 6451 and a second housing hole 6452, made in the second portion 645 of the joint 64, radially equidistant from the hinge axis C of the joint 64 and angularly spaced from each other along an imaginary circumference having a centre on the hinge axis C.

In particular, the angular distance between the first housing hole 6451 and the second housing hole 6452 is equal to the angular distance between the first tract 61 and the second tract 62 when the joint 64 is in the second relative angular position.

The releasable blocking means comprise at least one pin 68 slidingly associated to the first portion 644 and adapted to be selectively inserted into the first housing hole 6451 and the second housing hole 6452, so as to form an obstacle connection between the first portion 644 and the second portion 645 of the joint 64 and to realise the first relative position and the second relative position. In particular, the blocking means comprise a guide made in the first portion 644 of the joint 64 to allow the pin 68 to slide.

In the illustrated embodiment, said guide comprises a pair of flanges each provided with a through hole 6441 in which the pin 68 is simultaneously inserted, wherein the through holes are coaxial to each other and are each placed at the same radial distance from the hinge axis C at which the first housing hole 6451 and the second housing hole 6452 are placed.

The blocking means comprise an elastic element, for example a compression spring 69, adapted to push the pin 68 from the first portion 644 of the joint 64 towards the second portion 645 of the joint 64 such that when the through holes 6441 are aligned at one between the first housing hole 6451 and the second housing hole 6452, the elastic ele ment pushes and holds the pin 68 within said housing hole, thereby making an obstacle connection between the first portion 644 and the second portion 645 of the joint 64.

In practice, the pin 68 is movable between an engaged position, in contrast to the elastic force exerted by the compression spring 69, in which it is inserted into the housing holes, and a disengaged position, in which it is in a retracted position and allows the free rotation between the first portion 644 and the second portion 645 of the joint 64.

Regardless of the specific embodiment of the connection assembly, the box-shaped body comprises a rear portion proximal to the second portion 62 and a front portion distal from the second portion 62, and the element contacting the ground is placed solely at the rear portion.

The accessory 10 for high-pressure water jet cleaning machines may further comprise a tank 70 adapted to contain a second fluid to be delivered in order to optimize the cleaning action of the accessory 10.

Said tank 70, housed in the box-shaped body 20, may for example comprise a conduit communicating with the delivery nozzles 30 (i.e., for example, with the supply conduit 31 ). It is not excluded that the tank 70 may comprise a lower opening adapted to release the second fluid by gravity directly at the surface to be treated.

Furthermore, said tank 70 may comprise a further opening 71 at which to pour, for exam ple manually, the second fluid to be delivered.

The accessory 10 for high-pressure water jet cleaning machines may further comprise an adjustment device 72, connected to said tank 70, and configured to partialize the flow rate of a second fluid to be delivered.

Said adjustment device 72 may comprise, for example, a valve provided with a shutter, the movement of which, controlled by a knob, makes it possible to modulate the flow rate of the second fluid.

It is not excluded that the adjustment device 72 may be of any known (different) type. The invention makes available a cleaning assembly comprising the accessory 10 and an extension conduit 80 of the delivery lance adapted to fluidically connect the delivery lance to the accessory 10.

Said extension conduit 80 comprises a straight tube provided at a first axial end thereof 801 with a hydraulic connector 81 configured to realize a hermetic fluidic connection with the hydraulic connector 63 and at an opposite axial end thereof 802 with a hydraulic con nector 82 adapted to realize a hermetic fluidic connection with the delivery lance.

In view of the foregoing, the operation of the accessory 10 for high-pressure water jet cleaning machines is as follows.

The high-pressure water jet cleaning machine of the delivery assembly sends high-pres sure water to the delivery lance via the delivery gun.

The accessory 10 allows to realise two modes of use, a first mode of use of which pro vides that the first tract 61 , to which the delivery nozzles 30 are rigidly fixed, is in the first relative position with respect to the second tract 62, so that, while the user conveniently holds the delivery gun to which the accessory 10 is connected, said delivery nozzles 30 deliver fluid in a direction substantially orthogonal to the lying plane of the surface to be treated. In this mode of use, the accessory touches the surface to be treated by means of the brush 40, for example by means of the brush and the element contacting the ground.

A second mode of use of the accessory 10 provides that the first tract 61 , to which the delivery nozzles 30 are rigidly fixed, is in the second relative position with respect to the second tract 62, so that the user can tilt the box-shaped body 20 and with it the delivery nozzles 30 to sweep away, by means of the water jet, the dirt present on the surface to be treated. In particular, in said second mode of use of the accessory 10, the fluid delivery direction E and the lying plane of the surface to be treated form an acute internal angle. In particular, the lower perimeter edge 22 of the box-shaped body 20, which in the first mode of use is lying on a plane parallel to the lying plane of the surface to be treated, in said second mode of use lies on a plane forming an acute internal angle with said lying plane.

When the user moves the accessory 10 in a tilted position, it contacts the surface to be treated, preferably only, by means of the element contacting the ground, namely the wheels 50.

In order to switch from the first mode of use to the second mode of use of the accessory 10, it is possible to intervene manually on the joint 64, by rotating the first tract 61 with respect to the second tract 62 and blocking them by means of the pin 68.

The invention thus conceived is susceptible to several modifications and variations, all falling within the scope of the inventive concept.

Moreover, all details can be replaced by other technically equivalent elements.

In practice, the materials used, as well as the contingent shapes and sizes, can be what ever according to the requirements without for this reason departing from the scope of protection of the following claims.