Electrolytic pickling, passivatinq and cleaning machine of metal surfaces.

The present invention relates to an electrolytic pickling, passivating and cleaning machine of metal surfaces. The machine of the invention can be used in companies and services where metal surfaces are passivated, pickled and cleaned (for example, in medical, food or industrial sectors).

Currently, pickling, passivating and cleaning operations of metal surfaces are performed either by immersing the surfaces in static bath or spreading the passivating product with a brush or spray on the metal surface, letting it work, and then rinsing it, in general with solvents. These operations may partially ruin the metal finishes.

The purpose of the present invention is to eliminate the drawbacks of the known art by devising a pickling, passivating and cleaning machine of metal surfaces that is effective, practical, versatile, inexpensive and simple to use and to make.

This purpose is achieved according to the invention with the characteristics listed in the attached independent claim 1.

Advantages embodiments of the invention will appear from the dependant claims.

The machine according to the invention allows for pickling, passivating and cleaning metal surfaces by directly spreading a detergent that is ionized with the passage of electrical current and impregnates a special buffer in such a way that it acts electrolytically. In this way the detergent can activate its pickling, passivating and cleaning action immediately. The detergent can be immediately rinsed and sucked by means of a suitable extraction unit that is integrated in the machine. Although delicate, metal finishes are not ruined at all. This is one of the most important aspects for practical applications compared to other known methods.

Another advantage of the machine of the invention is the non-harmfulness of the detergents that can be used (they must be simply detergents with ionizable molecule). Therefore, also detergents sold on the market that are classified as non-harmful can be used. The process is performed at very low voltage, thus also washing machines provided with delicate electronic parts and without risks for washing operators. The process does not produce harmful organic vapours or other harmful vapours, except for the fumes intrinsically arising from metal pickling, which are immediately extracted and filtered with carbon filters.

The machine of the invention allows for working metal surfaces easily with any size, not only on small surfaces as it is possible with the known electrolytic bath systems. The machine is portable and has easy access in all settings, both working and domestic ones.

Additional characteristics of the invention will become evident from the detailed description below, which refers to a merely illustrative, not limiting, embodiment, as shown in the enclosed figures, wherein: Fig. 1 is a diagrammatic view that shows the blocks of the machine of the invention;

Fig. 2 is a perspective view of the machine of Fig. 1 ;

Fig. 3 is a side view of the gun or fluid dispensing nozzle of the machine of

Fig. 1 ;

Fig. 4 is an exploded axial view that shows the elements of the head of the nozzle of Fig. 3;

Fig. 5 is a view of the head of Fig. 4 in assembled condition; Fig. 6 is a side view of the head without buffer and lid; and Fig. 7 is a top view of the head of Fig. 6.

Referring to the aforementioned figures, the electrolytic pickling, passivating and cleaning machine of metal surfaces according to the invention is described, which is generally indicated with reference numeral (100).

Referring to Figs. 1 and 2, the machine (100) comprises a gun or nozzle (1 ) used to dispense a fluid on a metal surface (S) to be pickled, passivated or cleaned. To that purpose, the nozzle (1 ) is connected to a detergent tank (2) by means of a hose (20). The detergent is any type of liquid that can be ionized by applying a potential difference.

A compressor (C) is connected to the detergent tank (2) by means of a hose (21 ) to feed compressed air in such a way to transport the detergent towards the nozzle (1 ). A shut-off valve (22) is arranged at the outlet of the compressor (C). Two shut-off valves (23, 24) are arranged at the inlet and outlet of the detergent tank (2), respectively.

The machine (20) also comprises a neutralizing liquid tank (3) and a rinsing water tank (4) that are connected to the compressor (C) by means of the connection hose (21 ).

Corresponding valves (33, 34) and (43, 44) are arranged at the inlet and outlet of the neutralizing liquid tank (3) and rinsing water tank (4). According to the specific needs, the neutralizing liquid and rinsing water tanks (3, 4) can be connected to the nozzle (1 ), by means of the hose (20) of the nozzle that is disconnected from the detergent tank (2) and connected to the neutralization agent tank (3) or rinsing water tank (4).

As shown in Fig. 2, the tanks (2, 3, 4) have a basically cylindrical shape and are arranged on a base (101 ) of the machine, near a lateral border of the base (101 ). The machine (100) also comprises an electricity generator (G) adapted to generate a current from 5 to 120 A. Advantageously, the electricity generator (G) can be powered with alternate current from the electrical mains, that is to say with 220 Vac voltage. In such a case the electricity generator is equipped with transformer to transform the mains voltage into lower voltage and a rectifier to rectify the mains sinusoidal current and provide rectified alternate current (that is to say with square wave) ranging from 5 to 120 A.

The generator (G) comprises two electrical wires (GO, G1 ) that are the earthing electrode and positive electrode of the generator, respectively. The electrical wire (G1 ) is connected to the nozzle (1 ); instead, the electrical wire

(GO) is connected to the metal surface (S) to be treated. In this way an electrical circuit is closed between nozzle (1 ), detergent fluid dispensed by the nozzle and metal surface (S).

As shown in Fig. 2, the generator (G) and compressor (C) are arranged on the base (101 ) and protected inside a box (102).

The machine (100) also comprises an extractor (5) with a hose (50) ending in an extraction opening (51 ) arranged near the metal surface (S) to be treated, in such a way to extract the fumes produced by the pickling process and the excess liquid that would remain on the surface (S). Advantageously, the extractor (5) comprises active carbon filters in such a way to hold the harmful substances of the fumes and release the depurated fumes in the atmosphere through an exhaust opening (52) provided at the upper end of the extractor.

On the contrary, liquids are collected in a specific container for disposal.

Referring to Fig. 3, the nozzle (1 ) comprises a tubular body (10). A handle (1 1 ) is provided at the rear end of the body (10), comprising a trigger or actuation lever (12) used by the user to adjust the quantity of fluid to be dispensed. The handle (1 1 ) is provided with a button (13) to switch the machine (100) on or off. LED's (L) are mounted on the front part of the body (10) and arranged on a collar to illuminate the work area.

Two electrical power cables (14, 15) are connected to the button (13) and LED's (L), respectively. The cable (14) conducts 24 Vdc voltage to actuate the switch (13) and the cable (15) conducts 7 Vdc voltage to power the LED's (L).

The power cables (14, 15) are connected to a suitable power supply unit powered from the electrical mains or batteries to take the necessary electrical power. Advantageously, the electrical cables (14, 15) can be connected to the generator (G). In such a case the generator (G) will be provided with transformers to transform the mains alternate voltage and provide 24V and 7V direct current voltages.

A connection (16) is provided in the body (10) to connect the fluid feeding hose (20). The connection (16) communicates with a pipe (T) made of conductive metal arranged inside the body (10). The electrical cable (G1 ) coming from the generator (G) is connected to the metal pipe (T). The electrical cable (G1 ) gives voltage lower than 10 V, preferably about 3 V in rectified alternate current.

An extension rod (6) is telescopically mounted in the tubular body (10) of the nozzle, in such a way to adjust the length of the nozzle (1 ). An articulation

(60) is provided at the end of the rod (6), supporting a dispensing head (7) in order to direct the head (7). The articulation (60) is provided with knobs (61 ) for manual adjustment of the inclination of the dispensing head (7). The head

(7) supports a buffer (8) that is impregnated with treatment liquid. The metal conductive pipe (T) is inserted into the rod (6) and protrudes from the front end of the rod (6) to connect with the head (7). Advantageously, an external connection pipe (T1 ) connects the conductive pipe (T) inside the extension rod (6) with the head (7).

Clearly, communicating conduits obtained inside the body (10) and the rod (6) can be provided instead of the pipes (T, T1 ).

Referring to Figs. 4, 5, 6 and 7, the head (7) comprises a tubular body (70) made of insulating material. The body (70) is internally empty and comprises an internal chamber (78) (Figs. 5 and 6). A connection (71 ) that communicates with the chamber (78) axially protrudes from an end of the tubular body to receive the end of the connection pipe (T 1 ). In such a way the fluid is fed inside the chamber (78) of the head (7). Although the connection (71 ) is illustrated in lateral position in the aforesaid figures, it can be arranged on the lateral wall of the head in order not to hinder the connection of the head with the telescopic rod (6).

A plurality of grooves (72) (Figs. 6 and 7) is obtained on the lateral external surface of the body (70) of the head in order to make the fluid flow. A plurality of radial holes (73) is obtained in the grooves (72), in communication with the internal chamber (78) of the head (7) to let the fluid out.

A connection bar (9) is mounted in the body (70) of the head, externally protruding from the head to connect the head (7) with the articulation (60) of the nozzle (1 ). To that end, the connection bar (9) is provided with a notched wheel (95) that is connected to the articulation (60) of the nozzle in order to allow for 360° rotation of the head (7) around the axis of the notched wheel (95).

The connection bar (9) is made of metal conductive material to transmit the electrical current to the electrolyte liquid inside the chamber (78) of the head (7).

As shown in Fig. 4, the conductive connection bar (9) is basically shaped as an overturned-U and provided with a base plate (90) that is recessed in the body (70) of the head, in such a way to be in communication with the chamber (78) of the head where the fluid passes. The base (90) of the conductive connection bar is fixed to the body of the head by means of screws (V) that are screwed into corresponding holes (94) of the base (90) of the bar. Accordingly, the body (70) of the head is provided with holes (74) that match the holes (94) of the bar to receive the screws (V).

The part of the bar (9) outside the head is covered with insulating material (91 ) to ensure correct insulation towards the outside.

As shown in Figs. 4 and 5, a buffer (8) with tubular shape is arranged on the body (70) of the head (7). The buffer (8) is composed of a cloth that is wrapped around the head and allows for uniform distribution of fluids on the surface to be treated (S), while removing the dirt. The buffer (8) is preferably made of felt.

A lid (75) made of insulating material is arranged on the buffer (8) to block the buffer (8). The lid (75) is fixed to the body (70) of the head by means of a screw (76). To that end, the lid (75), the buffer (8), the body (70) of the head and the base (90) of the bar are provided with corresponding holes (77, 87,

77', 97) for the fixing screw (76).

The head (7) allows for passage of fluids, including the detergent, that is ionized through the action of electricity. It must be noted that the head (7) is made of non-conductive material, not to disperse electricity and not to overheat components. Electricity inside the head (7) is conducted and distributed only by the conductive bar (9).

The special shape of the head (7) allows for correct distribution of electricity in order to ionize the detergent inside the head, and correct dissipation of the heat produced, in order not to damage either the head (7) or the felt buffer (8) that is wrapped around the head. At the same time the head (7) distributes the liquid on the buffer (8) uniformly, thus correctly washing each metal or in any case conductive surface.

Following is a description of the operation of the machine (100) of the invention.

Referring to Fig. 1 , the earthing wire (GO) of the generator (G) is connected to the surface (S) to be cleaned. The pipe (20) of the nozzle (1 ) is connected to the detergent tank (2). The generator (G) and compressor (C) are activated. The detergent liquid fed inside the nozzle (1 ) starts the ionization phase and the buffer (8) is impregnated with detergent.

The buffer is put in contact with the surface (S), thus closing an electrical circuit composed of generator (G), earthing wire (GO), metal surface (S), ionized liquid of buffer (8), conductive bar (9), conductive pipe (T) inside the nozzle (1 ) and electrical wire (G1 ) that returns to the generator (G). The voltage needed for operation is approximately 3 Volt; therefore, it does not produce harmful electrical currents for cleaning operators and does not damage the surface finishes of the metal (S) that is being cleaned.

After a first passage with ionized detergent, the compressor (C) and generator (G) are stopped and the extractor (5) is activated, arranging the extraction opening (51 ) on the metal surface (S) in such a way to extract the fumes produces by pickling process and excess liquid.

Then the pipe (20) of the nozzle is connected to the neutralizing liquid tank (3). Now a second passage with neutralizing liquid is performed on the surface (S).

The compressor is switched off and the pipe (20) is connected to the rinsing water tank (4). Finally, a third rinsing passage is performed. Numerous variations and modifications can be made to the present embodiment of the invention by an expert of the field, while still falling within the scope of the invention as claimed in the enclosed claims.