BEVERAGE VENDING MACHINES

The present invention concerns a hydraulic vibration pump usable in the beverage vending machines field, such as tea, coffee or similar beverages etc., which performs automatic supply of said beverages, through for instance vending machine or coffee machine of different type, for domestic use as well, or in the industrial field of appliances in general.

It is known that for beverage supplying through vending machines, the factors to be considered are various in order to optimize both quality yield, and machine reliability, and the quality of the service provided to the user. Said factors are dependent, of course, in large part by components part of said machines, comprising at least a tank, a pump, a boiler (in case of coffee machines) and a delivery system. Between said components is certainly of fundamental importance the hydraulic pump regulating the water inflow to the coffee machine or to the vending machine, and operation and performances thereof, affects all the following beverage making and supplying steps.

Therefore it is to be considered particularly important said pump being reliable and functional. But there is a further feature concerning coffee machines and vending machines, that depends in large part on the hydraulic pump, and it is considered particularly important for the quality assessment of said devices, that is the total cost of the machine and of its maintenance, which is particularly influenced by the hydraulic pump cost and by its maintenance costs.

It is known in fact that, said devices can be installed both in private houses and work environments like offices, industries, public buildings, schools or hospitals as well, thus certainly one fundamental assessment for choosing a coffee machine conditioning the final customer, over the article appearance itself, is its cost. The cost factor is quite always driven by the user qualitative assessment, in particular for installations in multi-user environments where coffee machine use is constant and continuous, as pointed out for hospital or offices etc.. In this case the machine reliability is particular relevant, in fact the machine has to be as reliable as possible, or affected by few breakages, malfunctions and few maintenance requirements in terms of interventions number, and costs of said interventions which may comprise, over ordinary cleaning, in worst cases spare part cost as well in case of unexpected damages.

It is known that one of the most expensive damage factor is, indeed, the replacement of the hydraulic pump necessary for the coffee and vending machine operation.

The user and the manufacturer are confronted about a problem indeed bundensome for both: for the user the higher cost of the coffee or vending machine is largely due to the hydraulic pump and its potentially high maintenance cost, and for the manufacturer too the problem is the high production cost of said coffee or vending machine mechanical part. The manufacturer, as it is known, is obliged to have to meet certain reliability standards, in order not to lose the reputation of the manufacturer himself resulting in a serious economic damage, in addition the manufacturer is obliged to comply with technical and health standard imposed by law on mechanical components which come into contact with food liquids or other food substances.

Said standards, as it is known, are regulated by law and the manufacturer undergoes long and strict controls for each product falling in said category.

For instance, a new generation electromagnetic vibration hydraulic pump for coffee machine is known, as that one disclosed in EP1365149 B, which differently from pumps existing on the market is provided with a double pole piece for increasing performances and improving the magnetic circuit, therefore three pole pieces overall (46, 46', 52) for the cited pump, as to achieve any intensity pressure level - very relevant factor for the coffee machine - without increasing too much the magnetic circuit dimension, circumstance which would imply a pump with increased size and cost. Such a prior art vibration pump is considered a good product, suitable for providing medium-high performances, with acceptable qualitative standard. Such a product partially solved size and cost problems and performance improving in respect of traditional and known rotary pumps previously used for these industrial applications, and also said vibration pumps allowed to achieve the required high pressure.

Anyhow said vibration pump because of further technical features described hereinafter, it is not able to completely exploit the features of the magnetic circuit therein included, because of the presence of a magnetic gap represented by the sleeve thickness, significantly limiting performances of said pump. Furthermore, said known pump comprises a magnetic circuit with double pole piece (hereinafter described with the annexed figures) one of which deliberately housed in contact with food liquid, which will be treated by the aforementioned machine, both a coffee machine and a vending machine or any device wherein is used a food liquid, wherein a said pump suits for this purpose.

It is clear, therefore, that this factor implies many troubles or problems, as said kind of pumps has to undergo accurate controls to be compatible to all health laws of different fields, said laws that moreover forbid some material use not being compatible with food fluids. This fact involves the adjustment to predetermined qualitative standards, as well as use of materials which have to stay in contact for a long time with food liquid, said materials are very expensive because of they have to undergo food standards and law requirements. Moreover the fact that the pole piece disclosed in EP1365149 Bl is inside the sleeve implies serious troubles in maintenance condition, as when this pole piece is replaced, it is necessary to disassemble the entire pump. Furthermore this kind of pumps comprises usually more components, as it is known, this fact gets the price of said pumps increased.

Finally, with regard to the prior art is pointed out that documents US4122378, DE19542914, EP2375054, EP0288216 disclose technical solutions affected by already described disadvantages, being configured with a couple of pole pieces wherein one is inside the sleeve (the fact that said pole piece is inside the sleeve prevents its production with materials with usage restrictions with food fluids, according to technical standards or laws), or anyway a couple of pole pieces outside the sleeve but of the same dimensions, as the sleeve has a constant diameter throughout its length. Thus said pole pieces, are characterized by the inner diameter greater than the mobile core outer diameter, and this fact implies an oblique pulling force applied on the mobile core, and thus characterized by a little effect intensity in respect of the object of the present invention.

It is an object of the present invention to solve the here described prior art problems. Thus it is an object of the present invention to disclose a vibration pump for coffee and vending machine or device similarly suitable for food use, that could combine a reduced size advantage with a low cost device.

An object of the present invention is therefore to propose a vibration pump, having a reduced production cost, allowing to reduce costs for the final customer as well.

Therefore an object of the present invention is to disclose a vibration pump suitable for reducing maintenance costs.

Another object of the present invention is to improve and increase said vibration pump lifespan. A further object of the present invention is to disclose a vibration pump suitable for guaranteeing a good reliability and characterized by a high quality level.

Furthermore is an object of the present invention the improvement of prior art pump performances.

A further relevant object of the present invention is to exclude food fluid from the contact with steel which may became rusted, although for food use.

Therefore it is an important purpose of the present invention to manufacture a low cost pump, characterized by high performances, ease to be assembled, characterized by reduction of number of components in contact with food fluid.

Then, it is an object of the present invention to improve reliability of said vending or coffee machine in general.

Still a further object of the present invention, is to improve the manufacturer and final customer satisfaction in economic terms of maintenance cost saving.

Finally It is an object of the present invention to improve the final user satisfaction and qualitatively improve the devices.

These and other objects of the present invention will be achieved by the vibration pump hereinafter described, which is suitable for solving all prior art problems hereinbefore mentioned.

The present invention discloses an innovative vibration pump comprising an oversized pole piece with an optimized magnetic circuit.

Said vibration pump comprises in particular at least a solenoid, a mobile core inserted in a system of springs or like elements, inside a cylindrical housing (usually defined sleeve or inlet/armature tube) and at least two check valves applied on the outlet of said pump, said pump comprising an oversized pole piece placed, between the coil and the sleeve, close to the pump fluid inlet.

The pole piece arranged as aforementioned, advantageously may be characterized by a higher pole piece diameter, which is realized increasing the pole piece loop thickness towards the inner side thereof, thus decreasing the loop pole piece inner diameter of about 20%-60%, that allows to achieve a more performing magnetic circuit for the reasons that will be described in detail in the attached figures.

Said innovative vibration pump disclosed in the present invention, in a particularly advantageous way, thus allows to optimize the exploitation of the pump magnetic circuit, thus improving and increasing pump performances.

Advantageously the performances enjoy a considerable increase, because said pump has the plunger pull magnetic force increased, caused by the vertical attraction and by the higher magnetic field originated by the expansion increase.

Furthermore, advantageously, the pole piece will be worn much less, because it is not in contact with a such corrosive agent as water or any detergents, and moreover it is not in contact with the plunger which for every pulse thereof impacts against it.

Moreover, the pump manufacturing, besides improving the vibration pump total performances, allows to reduce the copper use necessary for the pump manufacturing, therefore reducing manufacturing and sale costs in an important way, as it is known to any person skilled in the art.

Furthermore said pump will be advantageously manufactured without important parts such as the pole piece in contact with the food fluid, thus certification level and health controls and the costs correlated thereof will be significantly reduced.

These and other objects will be achieved by the innovative vibration pump suitable for the use in coffee and vending machine, or washing machine field, will became apparent from the hereinafter detailed description of a preferred embodiment, with reference to the figures of the accompanying drawings in which:

Fig. 1 shows a known vibration pump related to the field of the present invention in a side sectional view;

Fig. 2a shows a vibration pump preferred embodiment according to the present invention in a side sectional view;

Fig. 2b shows a particular relevant detail of the innovative vibration pump disclosed in

Fig. 2a

Fig. 3a shows a vibration pump preferred embodiment according to the present invention in a side sectional view;

Fig. 3b shows a particularly relevant detail of the vibration pump disclosed in Fig. 3a. With reference to figure 1, for sake of completeness, a known vibration pump is shown as described in EP1365149 Bl, considered the more relevant relative to the solved technical problem, and to advantages achieved as for the present invention. In figure 1 is thus shown a side sectional view of a prior art vibration pump, provided with a double pole piece.

A vibration pump 1' usually comprises a coil 2', a mobile core 3', inserted in a system of springs 4', 5' (as shown in figure 1) having the same diameter, and placed inside the sleeve 6', whose diameter is constant on the work room of mobile core 3', furthermore said vibration pump comprises at least two check valves 7', 8' inserted in an outlet channel 9'.

The coil 2' is usually powered by alternate voltage in a circuit comprising a diode, thus only positive phase, which activate the mobile core 3' through a magnetic field in turn causing a magnetic force, said mobile core 3' is therefore pulled upward, thus compressing the spring 4' up to its top dead point.

The spring 4', during its compression, absorbs mobile core 3' kinetic energy and returns it when magnetic force fails, causing said mobile core 3' to change direction of movement. In this position the spring 5' is compressed, causing the mobile core 3' gradually to slow up to its bottom dead point.

When the magnetic force turns back on, it attracts the mobile core 3' upwards, thus causing an oscillating movement between its bottom and top dead points.

It is pointed out that said known pump, particularly performing, comprises three different pole piece 10', 11', 12', for originating the magnetic field.

It has to be noted particularly that, while pole piece 11', 12' are normally comprised in any similar known pump and have inner diameter greater than mobile core 3' outer diameter, the pole piece 10' instead is added inside the sleeve 6' to improve the pump magnetic pull force and improving its performances, said sleeve 6' has the outlet portion diameter equal to the inlet portion diameter, i.e. the one affected by the pole piece 10', 11'. Said pole piece 10' has therefore some advantageous effects, but the insertion inside the sleeve 6' of said pole piece, as it appear evident, makes the pump manufacturing more expensive and the assembly more complex and bundensome, and this fact complicates the manufacturing and the possible maintenance of said vibration pump, because the pole piece 10' removal, requires the pump full disassembly. Furthermore between the pole piece 10' and the pole piece 11', there is the sleeve 13' which establishes a magnetic gap between the two pole piece 10', 11', while the pole piece 11' remains in contact with the magnetic bracket 14', making less performing the magnetic circuit and originating in that point magnetic concentrations getting worse the effective pull force when the coil operates.

The mobile core 3', compressing the spring 4', causes a depression suitable for sucking water through the sleeve 6' hole and the corresponding pole piece 10' hole added inside it - which is therefore in contact with the food fluid -filling thus the room beyond the check valve 7'. When the mobile core 3' inverts its movement, closes the check valve 7', compressing the water in the cylinder and pushing towards the check valve 8', which opens causing coming out water in the same core movement direction, according to a determined pressure and flow rate.

With reference now to figure 2a, a particular preferred embodiment of the vibration pump with oversized pole piece according to the present invention is disclosed, for clarity in comparison with the known pump described in the document EP1365149 figure 1.

As it is obvious, the innovative pump 1 here described comprises as well at least a coil 2, a mobile core 3, inserted in a system of springs 4, 5 inside a sleeve 6, and at least two check valves 7 and 8, inserted in an outlet channel 9. For the pump operation see what described in figure 1, because as it is known, the operation is the same.

What is particularly innovative, inventive and advantageous in the vibration pump 1 object of the present invention and it is evident from the figures 2a and 2b annexed, is the oversized pole piece 20 introduction outside the sleeve 6 and surrounding its inlet portion 61, configured differently in relation to the known prior art, circumstance that consequently increases the magnetic circuit. It appears evident that in the vibration pump 1 of the particularly preferred embodiment according to the present invention/the oversized pole piece 20 is the only one close to the inlet portion 61 of the sleeve 6, therefore the vibration pump 1 comprising overall two pole pieces, the oversized pole piece 20 and the known pole piece 21, which are both arranged outside the sleeve 6, thus said pole pieces 20, 21 are separated from contact with each of the springs 4 and 5 inside the sleeve 6.

As clearly shown in figures 2a and 3a the spring 4 has a diameter lower than the spring 5, therefore this configuration is different in respect of known vibration pumps.

Thus said oversized pole piece 20 is made of a thickness S cylindrical loop having an inner diameter D" reduced in respect of both the inner diameter of the pole piece 21, the latter so that has a reduced thickness of the oversized pole piece 20, and relative to the inner diameter of the known pole piece marked for instance with reference number 11' in figure 1, the latter placed surrounding the inlet portions of the known pumps. Finally as hereinafter described said pole piece 20 has an inner diameter D" decreased relative to the mobile core 3 outer diameter.

For instance (here in this preferred embodiment) said inner diameter D" is decreased of about 30-60%, or equivalently the oversized pole piece 20 thickness S is increased of 30- 50% in respect of the pole piece 21 and pole piece thickness of prior art, in order to obtain a more performing magnetic circuit.

In fact by increasingthe oversized pole piece 20 thickness S it is increased consequently the lower area 12 dimension, which involves with its magnetic field the mobile core 3 upper area 13, said mobile core 3 is thus more powered and effectively attracted, both for magnetic field increase caused by the oversized pole piece 20, and for the direction of the pull force produced, which in the present invention in substantially vertical, the lower face area 12 and the upper face area 13 having the same or anyway similar dimension.

In that way vibration pump 1 performances (in terms of increased flow rate and pressure obtained) according to the present invention are increased advantageously of about 30-40% (with regard to the present embodiment).

Furthermore in the present invention the fact that all the pole pieces are arranged outside the sleeve 6 facilitate their replacement in case of possible malfunctions and for the pump assembly, contrary to what happens for the known prior art EP1365149 Bl wherein for the inner pole piece 10' removal from the sleeve 6' it is necessary to fully disassemble the pump.

What here described is particularly evident in figure 2b illustrating section DD', shown in dashed lines in figure 2a, to better highlight thickness S increase of the oversized pole piece 20 cylindrical loop.

By manufacturing the vibration pump 1 with oversized pole piece as here described, it is furthermore advantageously possible in an different embodiment to reduce the copper amount inside the coil , in order to preserve the same "good" performances of known pumps, up to about 40%; in this way the pull force decreases of about 40%, thus balancing performance increase of about 40% while reducing the pull force of the same percentage, thus obtaining a manufacturing vibration pump cost saving very important, therefore obtaining a high performance vibration pump being, as desired, low cost.

Furthermore in a possible different preferred embodiment, it is obviously preferred to obtain the hereinafter performances of about 40%, while maintaining the same copper amount, thus permitting to obtain a high performance vibration pump, at the same cost of a known pump, with an improved pull magnetic force as hereinbefore described.

Moreover in a particularly advantageous way, as it is shown from figures 2a, 2b, 3a, 3b, the vibration pump provided with the oversized pole piece 20 according to the present invention, in any embodiments, is characterized by a further particularly innovative feature, i.e. it has to be note that the oversized pole piece 20 is applied outside the sleeve 6 inlet and not inside, as it is in the known pump as it is seen in document EP1365149 figure 1; this inventive embodiment achieved by the applicant, allows to obtain a further innovative advantage, that is not having any circuit part here described in contact with food fluid, as for instance food fluid producing in a coffee machine or in vending machine in general. This feature involves a surprising amount of advantages, as for instance the possibility to use any material suitable for that use, which, as it is known, not being subject to any food standard, it may be less expensive and more performing. Moreover this feature makes the vibration pump 1 much more resistant to wear and corrosion caused on the prior art pole piece by the food fluid contact. Finally these features allow using ad hoc materials, not limited by food standard, thus increasing performances, and further decreasing costs.

Furthermore production controls will not undergo strict food standard controls to which the known pumps are subject, all that is an advantage for the manufacturer and for the possible coffee machine manufacturer who buy said pump, and for the final user caused by the chaining of costs/benefits which are achieved by the here described vibration pump with oversized pole piece.

From the manufacturing point of view, the sleeve 6 inlet portion 61 is modified in respect of the prior art, decreasing its outer diameter and anyway decreasing its total diameter in order to house said oversized pole piece 20 on inlet portion 61 outer face; the sleeve 6 inlet portion 61 is thus surrounded by said innovative oversized pole piece 20. Moreover a further structural modification is made to the principal spring 4, which has reduced diameter in respect of the spring 5, in order to be introduced and housed in the sleeve 6 inlet portion 61.

Therefore the spring 4 diameter is compatible with the inner and outer diameter of the sleeve 6 inlet portion 61 and consequently with the oversized pole piece 20 inner diameter D", and said diameters are lower respectively of spring 5 diameter, in turn compatible with the inner and outer diameter of the sleeve 6 outlet portion 62 wherein the spring 5 is inserted, and again consequently compatible with pole piece 21 inner diameter which surrounds the sleeve 6 outlet portion 62.

This modification, seemingly trivial, it is instead essential to allow the magnetic force, which draws down the mobile core 3, to be straight, and this is an essential feature for the pump correct operation.

For the person skilled in the art appear immediately evident that the constructive geometry and thus the pump assembly according to the present invention is really easier and more immediate in respect of the known pump hereinbefore described.

In fact the present invention discloses a vibration pump with oversized pole piece, wherein the pole pieces are two, namely reference numbers 20 and 21, and not three as for the known pump, i.e. numbers 10', 11', 12'. This feature involves two advantages very relevant in respect of the known prior art here described, first of all it is known among industry experts that components as pole pieces are very expensive, and the known prior art pump manufacture hereinbefore described, although it is a performing pump, is very complex, having to introduce the added po|e piece 10' inside the sleeve 6'. Furthermore between the pole piece 10' and the pole piece 1 , as hereinbefore described, there is the sleeve 13' that stops magnetic flux, making a magnetic gap between said elements, thus decreasing the pull force originated when the coil works.

Finally advantageously in the present invention instead the diameter D" inner area of the oversized pole piece 20 is in contact with the inlet portion 61 sleeve 6 outer area, and the diameter D" outer area of the oversized pole piece 20 is in contact with a magnetic bracket 23, improving obviously magnetic circuit made by these components, not being any magnetic gap between the magnetic bracket 23 and the pole piece 20 surrounding sleeve 6 inlet portion 61. This pump arrangement achieves great advantages for the pull force generated by the coil, and allows to attain high performances, in terms of flow rate and pressure.

Furthermore in figures 3a and 3b an embodiment of the vibration pump with oversized pole piece 20 according to the present invention is shown, wherein an O-ring 30 is inserted in the sleeve 6 to absorb possible impacts during plunger operation, and thus limiting the pump noise. It is in fact possible that the plunger follows different strokes with possible "out strokes", where said plunger may impact the sleeve 6 and further making a vibration besides noises, which can led the sleeve 6 to breakage. This problem is not frequent but it is however necessary to manage and if it is possible avoid thereto.

These are only some vibration pump preferred embodiments used in particular in beverage vending machine field and coffee machine or appliances in general, and in particular in the circuits of said devices, and any different embodiment of said vibration pump with oversized pole piece, wherein said pole piece is placed outside said sleeve, should be considered object of the present invention. Said pump, as mentioned, may show up alternatives to the previously described preferred embodiments, wherein modifications and changes concerning for instance the geometries chosen for the single movable and fixed elements, the materials adopted for each member, and even the specifications of the operative system, may be resorted to without however departing form the scope of protection of the present invention as defined in the appended claims.