Patent Description:
As known, high pressure washing devices, or high pressure water jet cleaners, generally comprise a pump, to which an electric motor is mechanically connected, for the purpose of supplying the pump with the mechanical energy required to pressurise a fluid, such as water, and send it to a delivery conduit.

This pressurised fluid is usually used to remove dirt from a surface and/or to rinse after washing with cleaning and/or sanitising liquids.

In particular, in order to wash a surface with cleaning and/or sanitising liquids, it is possible to use spraying machines, also called sprayers, which use pumps or compressors connected to a suitable spray nozzle to spray cleaning and/or sanitising liquids from a tank, so as to evenly deposit droplets of liquid on the surface to be treated.

Generally, after letting the cleaning/sanitising liquid act for a sufficient time, it must be removed, e.g., by rinsing with a high pressure water jet cleaner to ensure that no traces of the liquid remain on the surface.

One drawback encountered by an operator in charge of cleaning is that he/she has to carry both a high pressure water jet cleaner and a sprayer/atomiser. [The advantage is that the device does not have to be connected to/disconnected from the network every time].

<CIT> discloses a discloses a high pressure water jet cleaner including a pump provided with a suction duct adapted to be connected to a tank adapted to contain a liquid. A separate system comprises a pump provided with a suction duct adapted to be connected to a water network. <CIT> further discloses a high pressure water jet cleaner provided with a single pump provided with a suction duct adapted to be connected to a water network or to a tank adapted to contain a liquid.

The object of the present invention is to solve the drawbacks of the prior art, all within the framework of an efficient, rational and robust construction solution.

Such object is achieved by the features of the invention reported in the independent claim. The dependent claims outline preferred and/or particularly advantageous aspects of the invention.

The invention, particularly, makes available a high pressure water jet cleaner as defined in claim <NUM>.

Thanks to this solution, the user can carry out washing operations quickly and easily, as he/she always has the proper tool at hand, just carrying one single tool, i.e., a single high pressure water jet cleaner, and therefore without having to connect or disconnect different machines to the water network and/or electricity grid.

According to the invention, the high pressure water jet cleaner comprises a first electric motor mechanically connected to the first pump to activate it, a second electric motor mechanically connected to the second pump to activate it, and an electric power supply device configured to selectively connect the first motor or the second motor to an electric energy source. It is thereby particularly quick and convenient to select the function to be used by the high pressure water jet cleaner, between the classic water jet cleaner function of dispensing pressurized liquid (water) and spraying a cleaning and/or sanitising liquid. In addition, this allows rationalisation of motor sizing, as only one motor is allowed to be switched on at a time.

According to another aspect of the invention, the second pump may be configured to generate a maximum flow rate comprised between <NUM>/min and <NUM>/min and a maximum pressure comprised between <NUM> bars and <NUM> bars.

Spraying the liquid in the tank is thereby optimal.

According to yet another aspect of the invention, the second pump may be a vibration pump.

The high pressure water jet cleaner thereby has a high service life, as vibration pumps require few gaskets at the moving pumping members thereof, for example only one gasket is needed, and they generate a low pressure, so the members stressed by corrosive liquids such as cleaning agents and disinfectants are few and relatively little stressed, and their possible replacement is quick and easy. In detail, the components in contact with the fluid, i.e., the surfaces defining the fluid passage sections, are defined by stainless steel bodies, with the exception of the surfaces defined by the gaskets.

Another advantage of vibration pumps is that the second motor can be an integral part of the vibration pump, which helps to make the high pressure water jet cleaner more compact.

In further detail, the second motor may comprise a solenoid adapted to move a core of ferromagnetic material along an oscillation axis and the second pump comprises a pumping member slidably inserted into a pumping chamber and integral in sliding along the oscillation axis to the core of ferromagnetic material.

The invention may provide that the tank of the sanitising and/or cleaning liquid may be associated with the casing.

This makes the high pressure water jet cleaner particularly easy to handle, as the tank of the liquid to be sprayed can also be transported by acting on the casing of the high pressure water jet cleaner, e.g., by grabbing a handle.

Another aspect of the invention provides that the tank can be removably associated with the casing.

The tank can thereby be easily transported with the casing of the high pressure water jet cleaner, and at the same time, cleaning and/or refilling the tank are made easier thanks to the possibility of detaching it from the casing.

In addition, this feature allows to quickly and easily replace and clean the tank, even temporarily, with a larger tank. In particular, this last feature is assisted by the fact that a pipe connecting the suction conduit of the second pump with the tank can be removably associated with the tank, so that it can be detached from the tank and inserted into another tank, for example one with a larger capacity.

Still another aspect of the invention is that the casing may comprise a horizontal rectilinear guide adapted to guide the tank.

This feature makes it even easier and faster to remove the tank from the casing, furthermore, the solution is particularly robust as, guiding the fixing of the tank reduces the likelihood of damaging the tank due to a wrong positioning while inserting it into a housing seat of the tank.

In order to further improve the handiness of the high pressure water jet cleaner, the high pressure water jet cleaner may comprise, i.e., the casing to which the first pump and the second pump are associated, a first support adapted to hold the dispensing pistol and a second support adapted to hold the spray pistol.

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 accompanying drawings.

With particular reference to these figures, a high pressure water jet cleaner, i.e., a high pressure washing device, has been indicated with <NUM>.

The high pressure water jet cleaner <NUM> comprises a casing <NUM>, for example made of plastic material, preferably provided with a handle <NUM>, preferably made in a top portion of the casing, for grabbing the high pressure water jet cleaner by a user.

The casing <NUM> is rigid, i.e., not deformable under the normal forces acting thereon while using the high pressure water jet cleaner. In practice, the plastic material used and the thicknesses of the casing are such that the casing is essentially rigid.

In order to handle the high pressure water jet cleaner, in addition to the handle, the high pressure water jet cleaner may comprise a pair of ground contact wheels <NUM> rotatably associated with the casing, for example positioned externally to the casing.

With particular reference to <FIG>, the high pressure water jet cleaner comprises a first pump <NUM> associated with, i.e., fixed to, the casing <NUM> and preferably contained, for example entirely contained, within the casing <NUM>, i.e., within an internal cavity of the casing. The first pump <NUM> is provided with a suction conduit <NUM> adapted to be connected to a source of fluid to be pressurised, such as a water supply network, and a delivery conduit <NUM>.

The first pump <NUM> is preferably configured to generate a maximum pressure of more than <NUM> bars.

The first pump <NUM> may be one of an axial piston inclined plate pump, a reciprocating pump, or a piston pump with an eccentric shaft.

The high pressure water jet cleaner may comprise an inlet coupling fitting <NUM> (see <FIG>), rigidly associated with the casing <NUM>, accessible externally to the casing and in fluid connection with the suction conduit <NUM> of the first pump <NUM>. Substantially, the inlet coupling fitting <NUM> is connected by means of a pipe (not shown and located inside the casing) to the suction conduit <NUM> and is adapted to be connected by means of a pipe provided with a coupling fitting complementary to the inlet coupling fitting <NUM> to the fluid source to be pressurised.

The inlet coupling fitting is, for example, of the quick connect-disconnect type, as known by the skilled in the art and therefore not described further.

The high pressure water jet cleaner <NUM> includes a dispensing pistol <NUM> fluidly connected to the delivery conduit <NUM> of the first pump, for example (directly) by means of a flexible pipe <NUM>. In the embodiment shown, the high pressure water jet cleaner comprises a flexible pipe winding mechanism <NUM> provided with a roller <NUM> rotatably associated with the casing <NUM>, for example at the handle <NUM>.

The dispensing pistol <NUM> comprises a body provided with a handpiece and a dispensing lance <NUM> associated, for example removably, with the handpiece. The lance is provided, at one free end thereof, with a dispensing nozzle <NUM>. The dispensing pistol may be associated with any other cleaning tool as an alternative to the lance, such as a rotary brush. It must be specified that dispensing nozzle means a nozzle which is configured to withstand the pressures generated by the first pump and which is also configured to generate a compact, substantially rectilinear, jet of liquid. Dispensing nozzles generally have a mechanism configured to vary the shape of the jet between rectangular and fan-shaped, for example by moving a pair of opposite walls of the mechanism closer to and away from each other.

The dispensing pistol <NUM> may comprise a trigger <NUM> movable between a first position, in which the dispensing pistol does not dispense pressurized fluid, for example through the lance, and a second position, in which the dispensing pistol dispenses pressurized fluid, for example through the lance. In particular, the trigger <NUM> is located at the handpiece and activates a tap between a first position, in which it allows the flow of pressurised fluid from the delivery conduit <NUM> to the dispensing nozzle <NUM>, and a second position, in which it stops the flow of pressurised fluid from the delivery conduit <NUM> to the dispensing nozzle <NUM>.

The dispensing nozzle <NUM>, hence the dispensing pistol <NUM>, is in fluid communication only with the delivery conduit <NUM> of the first pump. The delivery conduit <NUM> is in turn connected at the outlet only with the dispensing nozzle <NUM>, hence with the dispensing nozzle <NUM>. In practice, the fluid pressurised by the first pump is dispensed only via the dispensing nozzle <NUM> (passing through the dispensing pistol).

With particular reference to the diagram in <FIG>, the high pressure water jet cleaner <NUM> comprises a first electric motor <NUM> configured to activate the first pump <NUM>. That is, the first electric motor <NUM> is mechanically connected to the first pump <NUM> to activate it so as to pressurise the fluid coming from the suction conduit. Altogether, the first electric motor <NUM> and the first pump <NUM> form a first motor pump of the high pressure water jet cleaner. The first electric motor may be, for example, only switched on or off, and when switched on, it activates the first pump at a pre-set activating speed to pressurise the fluid.

The first electric motor <NUM> is adapted to be electrically connected to an electric energy source E. The electric energy source E may be an electric connection cable adapted to be connected to the electricity grid and/or a battery.

In particular, the first electric motor <NUM> may only be activated between a first condition, in which it is switched on, i.e. in which it is electrically powered by the source of electric energy, and a second condition, in which it is switched off, i.e. in which it is not electrically powered by the source of electric energy and no electric current flows in the first motor. The high pressure water jet cleaner comprises a tank <NUM> adapted to hold a liquid, in particular a cleaning and/or sanitising liquid. The tank <NUM> is preferably made of polymer material at least in the parts in contact with the liquid. In the embodiment shown, the tank <NUM> is entirely made of polymer material.

The tank <NUM> comprises a fill up opening made in an upper portion thereof, i.e., in a top portion thereof, and a cap <NUM> for closing the fill up opening and removably associated with the tank.

The tank <NUM> is associated with the casing <NUM>, for example it is fixed to the casing <NUM>, preferably removably.

For example, the casing may comprise a recess <NUM> (see <FIG> in which the tank is removed from the casing) adapted to at least partially contain the tank <NUM>, so as to increase the overall compactness of the cleaner.

In particular, the tank comprises a portion adapted to be inserted into the recess and dimensioned in such a way as to deform plastically during insertion (or in such a way as to deform the recess) so as to realise a non-permanent inference connection with the casing. For example, the recess is of a form converging towards a bottom wall <NUM>, preferably lying on a vertical plane, of the recess itself in such a way as to realise said interference connection.

The casing may comprise a guide configured to guide the fixing of the tank <NUM> to the casing, for example to guide the insertion of the tank into the recess <NUM>.

Preferably the guide defines a substantially horizontal sliding axis, i.e., it guides the insertion of the tank into the recess <NUM> along a horizontal sliding axis. However, it is not excluded that in an alternative embodiment not shown, the guide may define a substantially vertical sliding axis and the recess may be shaped to accommodate the tank along a vertical insertion and extraction direction.

In the embodiment shown, the guide comprises at least one rectilinear relief <NUM>, preferably a pair of rectilinear reliefs <NUM>, made on walls of the recess opposite from each other and transverse to the bottom wall, projecting from a surface of the recess <NUM> in a direction approaching the centre of the recess. In detail, the relief <NUM>, i.e., the pair of reliefs <NUM>, extends along a substantially horizontal longitudinal axis.

In the embodiment shown, the guide is convergent, i.e., the longitudinal axes of the reliefs <NUM> are convergent, in particular towards the bottom wall <NUM>.

The guide also includes a groove made in the tank and shaped to accommodate at least partially the relief so that it slides over it. For example, the guide comprises a pair of grooves made on opposite walls of the tank and positioned and shaped so as to slide over the reliefs <NUM>.

The high pressure water jet cleaner <NUM> includes a second pump <NUM> associated, for example fixed without residual degrees of freedom, with the casing <NUM>.

In the embodiment shown, the second pump <NUM> is contained in a closed box-shaped crankcase <NUM>, rigidly fixed without residual degrees of freedom, for example screwed or hooked, to the casing <NUM>. However, in an embodiment not shown, the second pump <NUM> is contained in the same casing <NUM> within which the first pump <NUM> is contained.

The second pump <NUM> is provided with a suction conduit <NUM>, in fluid communication, for example by means of a suction pipe <NUM>, with the tank <NUM> adapted to contain the cleaning/sanitising liquid and independent, i.e., fluidly separated, from the suction conduit of the first pump. It is also evident that the suction conduit <NUM> is not in communication with the delivery conduit of the first pump.

The second pump <NUM> also comprises a discharge conduit <NUM>, which is independent from the delivery conduit of the first pump.

The second pump is preferably configured to generate a maximum flow rate comprised between <NUM>/min and <NUM>/min and a maximum pressure comprised between <NUM> bars and <NUM> bars. In particular, the second pump shown is configured to generate a maximum flow rate comprised between <NUM>/min and <NUM>/min and a maximum pressure comprised between <NUM> bars and <NUM> bars.

For example, the second pump <NUM> is a vibration pump.

Therefore, such vibration pump <NUM> is activated by a second motor which is an integral part of the vibration pump itself.

In particular, the second pump comprises a box-shaped casing <NUM>, for example made of steel, which is provided with a pumping chamber <NUM>, defined within a cylinder, in fluid communication with the delivery conduit <NUM>, by means of the interposition of a one-way delivery valve <NUM>, and the suction conduit <NUM>.

In the pumping chamber <NUM>, a pumping member is slidably inserted along a sliding axis X, which also acts as a one-way suction valve in selectively placing the pumping chamber <NUM> in communication with the suction conduit.

In particular, the pumping member comprises a piston <NUM>, slidably inserted in the cylinder along the sliding axis X and provided with an axial cavity <NUM> crossing it along the direction of the sliding axis X from one axial end to the other, placing the suction conduit <NUM> in fluid communication with the pumping chamber <NUM>.

The pumping member also comprises a spheroidal body <NUM> which is pushed by an elastic element <NUM> into a sealing seat for the spheroidal body itself made at an axial end of the piston <NUM> distal from the suction conduit, at the axial cavity <NUM>. The elastic element pushes the spheroidal body <NUM> towards said housing seat, e.g., in the direction away from the delivery valve, to occlude the axial cavity of the piston, thus acting as a suction valve.

The pump comprises an annular gasket <NUM>, e.g., housed in a housing groove made in the cylinder in which the piston slides, which insists on an outer shell of the piston (i.e., a cylindrical side surface of the piston).

The annular gasket <NUM> acts as a fluid-dynamic sealing between the pumping chamber <NUM> and the suction conduit <NUM>.

This gasket is preferably made of polymeric material.

Furthermore, this gasket is the only pump gasket in contact with the fluid to be pumped and with a moving body (the piston).

When the piston <NUM> moves along the sliding axis X towards the delivery conduit, the spheroidal body is pressed into its housing seat and closes the axial cavity <NUM> and the fluid is pushed by the piston and spheroidal body assembly towards the delivery one-way valve which therefore opens thus allowing the fluid to flow towards the delivery conduit. When the piston <NUM> moves along the sliding axis X towards the delivery conduit, the elastic element is configured in such a way that the spheroidal body distances itself from its housing seat in the piston allowing fluid from the suction conduit to enter the pumping chamber through the axial cavity of the piston.

In the case herein described of the vibration pump, the second motor is contained in the box-shaped casing <NUM> comprising the pumping chamber <NUM>.

In particular, the second motor comprises a solenoid <NUM> capable of moving a core <NUM>, made of a ferromagnetic material, along an oscillation axis coaxial to the sliding axis X. The solenoid is electrically powered in an alternating manner so as to generate a variable magnetic field such as to alternately move the core along the sliding axis between two end-of-stroke positions.

The core <NUM> has an axial cavity which passes through it from end to end in the direction of the sliding axis X and which is in fluid communication with the axial cavity of the piston, i.e., it is an extension of the latter in the core.

The core <NUM> is, for example, rigidly integral to the piston <NUM>, and is contained in a chamber <NUM> interposed between the suction conduit <NUM> and the pumping chamber <NUM>, i.e., the cylinder in which the pumping chamber is defined. In detail, the sealing gasket <NUM> is interposed between the chamber <NUM> and the pumping chamber.

The second motor comprises a first spring <NUM> and a second spring <NUM> housed in the chamber <NUM> and acting on the core from opposite axial ends of the core <NUM> itself, each respectively generating a force along the direction of the axis of oscillation in the direction opposite to the force generated by the other spring.

In the embodiment shown, downstream of the delivery conduit <NUM> the high pressure water jet cleaner comprises a by-pass valve (not shown), in fluid communication with the delivery conduit <NUM> and the tank <NUM> via a by-pass conduit <NUM>, which valve is associated with a pressure gauge (not shown) capable of measuring the pressure in the delivery conduit and controlling the by-pass valve according to said pressure. In particular, the valve is configured to be activated between a first position, in which it does not act on the flow downstream of the delivery conduit <NUM>, and a second position, in which it diverts the outgoing flow from the delivery conduit to the tank <NUM> via the by-pass conduit <NUM>. The valve switches from the first position to the second position when the pressure gauge detects a pressure above a pre-set threshold value. The pressure gauge can be either electronic or mechanical-hydraulic.

The high pressure water jet cleaner <NUM> comprises a spray pistol <NUM> fluidly connected to the delivery conduit <NUM> of the second pump, for example (directly) by means of a flexible pipe <NUM>.

The spray pistol <NUM> comprises a body provided with a handpiece and a spray lance <NUM> associated, for example removably, with the handpiece.

The lance is provided with a spray nozzle <NUM> at one free end thereof.

It must be specified that a spray nozzle is a nozzle configured to generate a conical, or possibly spiral, jet of fluid (diverging from an outlet hole in a direction moving away from the nozzle). Generally, such nozzles comprise therein a plurality of liquid guide surfaces from the second pump configured to direct the fluid along a direction tilted with respect to a central axis of the nozzle outlet hole.

The spray pistol <NUM> may comprise a trigger <NUM> movable between a first position, wherein the spray pistol does not spray the fluid pressurized by the second pump, for example through the lance <NUM>, and a second position, wherein the spray pistol does spray the fluid pressurized by the second pump. In particular, the trigger <NUM> is located at the handpiece and activates a tap between a first position, in which it allows the flow of pressurised fluid from the delivery conduit <NUM> to the spray nozzle <NUM>, and a second position, in which it stops the flow of pressurised fluid from the delivery conduit <NUM> to the spray nozzle <NUM>.

The spray nozzle <NUM>, and therefore the spray pistol <NUM>, is in fluid communication only with the delivery conduit <NUM> of the second pump. It is therefore not in fluid communication with the delivery conduit of the first pump. Similarly, the delivery nozzle is not in fluid communication with the delivery conduit of the second pump. In practice, the fluid pressurised by the second pump is sprayed only via the spray nozzle <NUM> (passing through the spray pistol).

In the embodiment shown, the second pump is of the vibration type and has therein the second motor as an integral part thereof, however, it cannot be excluded that in an embodiment not shown, the second pump may be of a different type, provided that it is configured to generate a maximum flow rate comprised between <NUM>/min and <NUM>/min and a maximum pressure comprised between <NUM> bars and <NUM> bars. In this case, the high pressure water jet cleaner <NUM> may include a second electric motor configured to activate the second pump. That is, the second electric motor is mechanically connected to the second pump to activate it in such a way as to pressurise the fluid coming from tank <NUM>.

The high-pressure water jet cleaner comprises an electric supply device, e.g., of the manual type, configured to selectively connect the first motor or the second motor to an electric energy source.

In particular, the electric supply device can be activated in three positions, a first position in which the first electric motor and the second electric motor are both switched off, a second position in which only the first electric motor is switched on and the second electric motor <NUM> is switched off, and a third position in which the first electric motor is switched off and only the second electric motor is switched on.

For example, the electric supply device can only be activated in said three positions.

It should be noted that "manual type" means that it can be activated manually, preferably only manually activated by an operator.

The first electric motor and the second electric motor are electrically connected to the electric energy source by means of the interposition of the electric supply device.

In the embodiment shown, the electric supply device comprises, i.e., consists of, a switch <NUM> configured to be permanently positioned in the three positions described above. Said switch <NUM> comprises a selection body which can be contacted directly by the user, for example a knob, for selecting the positions.

The high pressure water jet cleaner comprises a pressure limiting device (not shown) adapted to detect the pressure at the delivery conduit of the first pump and configured to interrupt the electric supply of the first motor when it detects a pressure, in the delivery conduit and/or in the pipe connecting to the dispensing pistol, greater than a predetermined threshold value.

For example, the pressure limiting device may comprise a switch placed on an electric connection cable connecting the electric supply device to the first electric motor.

Finally, the high pressure water jet cleaner may also comprise a first support <NUM>, adapted to hold the dispensing lance, and a second support <NUM>, adapted to hold the spray lance, both rigidly attached to the casing <NUM>. For example, it is the casing itself that makes the first support and the second support available, i.e., they are integral with the casing or parts thereof.

Each support comprises a flange which protrudes externally from an outer surface of the casing from which the flange derives and a grasping portion which retains the respective pistol, i.e., lance, and is associated with the end of the flange opposite to that in contact with the outer surface of the casing.

In the embodiment shown, each grasping portion is shaped as a tubular portion, e.g., oriented with a central axis transverse to a horizontal plane, into which the lance of the respective pistol is inserted. For example, an inner surface of the tubular portion, which contacts the pistol lance, is conical in shape with a cross-sectional area that gradually decreases from top to bottom.

The operation of the high pressure water jet cleaner according to the invention is as follows.

When the user has to clean and/or sanitise a surface with suitable products, he can act on the supply device and take it to the third position to activate the second pump and spray the liquid contained in tank <NUM> by means of the spray pistol.

After letting the cleaning and/or sanitising agent act for a sufficient time, the user can set the supply device to the second position to activate the first pump and use the dispensing pistol to sweep away the cleaning agent and dirt with the pressurised fluid.

When there is no more cleaning and/or sanitising liquid left, it is sufficient to remove the cap <NUM> to refill the tank and in the event that the cleaning and/or the sanitising liquid needs to be changed and all the liquid already in the tank needs to be removed or the tank needs to be washed, it is possible to remove the tank from the casing, e.g. by pulling it out horizontally, and remove the pipe(s), preferably connected by means of removable connections, connecting to the second pump.

When the job is complete, the user can place the pistols in their respective supports <NUM>, <NUM> and conveniently transport everything together, including the tank <NUM>, for example by simply gripping the handle <NUM>.

The invention thus conceived is susceptible to several modifications and variations, insofar as these are within the scope of the invention which is delimited by the appended claims.

Claim 1:
A high pressure water jet cleaner (<NUM>) comprising:
- - a casing (<NUM>),
- a first pump (<NUM>) associated with the casing (<NUM>), which is provided with a suction conduit (<NUM>) adapted to be connected to a water network and a delivery conduit (<NUM>),
- a dispensing pistol (<NUM>) provided with a dispensing nozzle (<NUM>) and fluidly connected to the delivery conduit (<NUM>) of the first pump (<NUM>),
- a second pump (<NUM>) associated with the casing (<NUM>), which is provided with a suction conduit (<NUM>) in direct fluid communication with a tank (<NUM>), adapted to contain a liquid, and independent from the suction conduit (<NUM>) of the first pump (<NUM>), and a delivery conduit (<NUM>) independent from the delivery conduit (<NUM>) of the first pump (<NUM>), and
- a spray pistol (<NUM>) provided with a spray nozzle and fluidly connected to the delivery conduit of the second pump, the high pressure water jet cleaner further comprising:
- a first electric motor (<NUM>) mechanically connected to the first pump (<NUM>) for activating it,
- a second electric motor (<NUM>,<NUM>) mechanically connected to the second pump (<NUM>) for activating it and
- an electric supply device (<NUM>) configured to selectively connect to a source of electric energy the first motor (<NUM>) or the second motor (<NUM>,<NUM>).