COUNTER FOR CODE PRINTING

Status of the art

In the paper money printing sector in which a mechanical rotary numbering machine is to be used, for instance the banknote printing sector, a perfect cleaning from the inks used for such printing type is very important.

Very often, especially when using numbering machines for realizing safety printed texts on paper money, such cleaning is not easy to perform because of the nature itself of the inks used which, because of the particular pigments and/or particles contained therein, feature a high resistance to removal, said inks containing metal particles. Such cleaning also entails a drawback in that they damage the morphology of the numbers that make-up the mentioned numbering machine, a damage that is not tolerable in the case that said numbering machines are used for printing codes on paper money.

The known techniques for cleaning said type of numbering machines are using ultrasounds or chemical solvents.

The use of ultrasounds for cleaning objects is described in a number of documents for instance document DE 199 14 746 which discloses an equipment described in said document which comprises a cylindrical drum with holes, a helical flat element on the inner side to displace the object to be cleaned, an ultrasound washing device with liquid, and an ultrasound oscillator. Similar equipment using solvents and ultrasounds for cleaning objects is also described in documents US 2009/139549, DE 2827 163 and US 2010/224114.

Such known equipment is not satisfactory for cleaning the mentioned numbering machines used for printing codes on paper money due to a number of reasons. First of all with respect to the degree of cleaning-obtainable because residues of ink remain on the numbering machines with the known equipment. The presence of residues of ink in numbering machines modifies the morphology of the numeric types of the printed codes and such modification is not acceptable indeed, should the numbering machines be used for printing codes on paper money, for instance banknotes.

A great importance also has the safety of the operators in charge of such maintenance procedure, should cleaning operation be performed by means of chemical solvents: the subject numbering machines are dipped in a bath of solvent whose degree of toxicity is high and consequently, notwithstanding the use of physical protections by the operators, a risk for the health of the operators in charge is still there. An improvement is definitely desirable also from this point of view.

Another very important element is maintaining the morphology of the numeric types of the numbering machine which are often spoiled owing to the known technique of cleaning the numbering machines by using the known equipment.

Note that the known technique does not use any mechanical device suitable for driving the tripping element of the mechanical rotary numbering machine. Such driving device was found to be surprisingly advantageous for an optimum cleaning of the numbering machine, together with other elements which will be illustrated below. The mentioned driving device and the other elements according to the present invention also proved to be suitable for maintaining the morphology of the numeric types of the mechanical numbering machine.

As already mentioned before, cleaning the numbering machine and maintaining the morphology of the numeric types of the numbering machine are indispensable requirements for mechanical numbering machines used to print numeric codes on paper money, for instance banknotes.

The need for solving the problems of the known technique which uses known equipment has been highlighted by the Italian company in charge of printing banknotes of the paper money manufacturing area of BANCA D'lTALIA (Bank of Italy). In order to solve such problems, Dottor Vincenzo Aliotto of the Printing Division and Dottor Maurizio Anibali of the Maintenance and Services Division cared about and, being it not possible for them to qualify themselves as inventors, they provided the inventor of the present invention with hints and suggestions suitable for identifying an invention according to the present patent application.

Description of the invention

The problems of the present art used in the known equipment for cleaning mechanical rotary numbering machines for printing codes on paper money, hereafter shortly also referred to as numbering machines, and for retaining the morphology of the numeric types of the numbering machines are solved by the equipment according to the present invention.

The equipment for cleaning at least one mechanical rotary numbering machine for printing codes on paper money also suitable for retaining the morphology of the numbers of the numbering machine, comprises a device for moving the numbering machine along a closed curved line. Such device can be for instance a shaft. The movement of said device for moving the numbering machine is obtained, for instance, by means of a motor. Integral with such device is a numbering machine which moves along a closed curved line on the basis of the motion imparted to the numbering machine by the mentioned driving device. The preferred trajectory of the numbering machine is the circular one, which is the easiest to implement, but other trajectories might also be used, as a matter of fact it has been possible to experimentally check that different trajectories of the numbering machine, associated with the actions exerted thereon by the other devices illustrated below, make it possible to obtain an advantageous cleaning of the subject numbering machine and solve the problems of the know techniques for cleaning the mentioned type of numbering machines, while also retaining the morphology of the numeric types of the numbering machine.

The numbering machine is placed inside a container which comprises a tank for containing an appropriate liquid detergent or an appropriate ready-to- print oil to dip the numbering machine but also for a better operation of at least one ultrasound device, preferably arranged along the surface of the. tank. The subject equipment is provided with at least one device capable of providing an air jet at a preferred minimum pressure of 0.38 MPa and at least one device for providing a liquid jet at a preferred minimum pressure of 0.5 MPa.

For a better and advantageous cleaning of the numbering machine, the equipment according to the present invention is equipped with a mechanical device suitable for driving the tripping element of the numbering machine, preferably active while the above mentioned ultrasound devices , etc. are operating.

Experimental tests also revealed that a numbering machine might be better cleaned if sprinkling said numbering machine with an appropriate ready- to-print oil.

Description of the figures

Figure 1 shows an equipment according to the present invention comprising a tank (2), at least one mechanical rotary numbering machine (1) for printing codes to be cleaned by using the subject equipment, a number of air jet devices (4) suitable for providing air at a minimum pressure of 0.38 MPa, and a device (7) for moving the mechanical rotary numbering machine (1) along a closed curved line, whose motion is obtained by way of any means and here represented, for explanatory purposes only, by the graphical representation of an electric motor. Figure 2 shows in detail a portion of the device (7) for moving at least one mechanical rotary numbering machine (1) along a closed curved line, the mechanical rotary numbering machine (1) for printing codes to be cleaned by using the subject equipment, a mechanical device (8) suitable for driving the tripping element (9) for a better and advantageous cleaning of the numbering machine (1).

Figure 3 shows a set of ultrasound devices (3) arranged along the surface of the tank (2). Said tank (2) is suitable for containing an appropriate liquid detergent (6), not graphically shown. Said liquid (6) is poured into the tank (2) both for a better operation of at least one ultrasound device and for easing up the cleaning of said numbering machine (1). Said tank (2) is also suitable for containing an appropriate printing oil, not graphically shown, as a matter of fact experimental tests also highlighted that a numbering machine might be better cleaned if sprinkling it with an appropriate ready-to-print oil. A preferred mode for such operation is dipping the numbering machine (1) into said oil poured into the tank (2).

Figure 4 shows the air jet devices (4) suitable for providing air at a minimum pressure of 0.38 MPa which are arranged in a preferred embodiment, i.e. along a parallelogram.

Figure 5 shows a device (5) for the liquid jet (6) suitable for providing the liquid (6) at a minimum pressure of 0.5 MPa. As already indicated in the previous paragraph, the movement of the numbering machine (1) along a closed curved line, associated with the actions exerted thereon by the other devices illustrated above, has an advantageous cleaning effect onto the numbering machine (1) which solves the problems of the known techniques used for cleaning numbering machines (1).

For the sake of completeness, it is here pointed out that the singular form or the plural form are used in the present description to foster a better disclosure of the invention according to the patent application. The different forms used shall not limit or be construed to limit in any way the scope of the present invention protection .