AN AUTOMATIC LIQUID FILLING DEVICE

Technical field

The present invention relates to an automatic liquid filling device which is particularly recommended for a type of filling featuring selectable weight and variable flow.

Background Art

As it is known, filling machines are present on processing lines for containers such as bottles and phials and, in the production line, the said machines are generally followed by capping machines .

There are different types of filling machines currently on the market, which differ in the way the container is filled.

A first type consists of weight filling machines which feature electronic scales which must be calibrated according to the amount of product to be placed in the containers, with adaptations according to the different characteristics of the products, which may be liquid, foamy, dense, creamy, moulded, powdered, and granulated.

In particular, the net weight filling machines feature a system which controls a pneumatic piston tap that is managed by a circuit board that processes an analogue electric input from a weighing scale and selects how much liquid to dispense after subtracting the container tare weight. The system j ust illustrated is efficient, but proves expensive due to the assembly and management of electronic components, which often become less accurate and operational as a result of the presence of significant moisture levels in the workplace. Furthermore, another drawback originates from the fact that the machine in question is particularly laborious to manufacture because it requires a significant number of components, thereby impacting on both production costs and management and maintenance costs.

In addition, assembling the components is also rather complicated and demanding due to the number of elements compri sing the filling machine. In particular, with the net weight type filling system illustrated above, a number of drawbacks have been encountered when the product to be filled is of a flammable or explosive type. Indeed, in the presence of these types of materials, special authorisations and certifications are required for the electrical components, as there is a risk of explosions or fires being caused if the product comes into contact with any sparks.

In addition, a further drawback encountered with the aforesaid machines consists of the frequent machine downtime resulting from the electronic components wearing due, in part, to the moisture present in the operating environment which makes the scales unable to properly weigh the amount of liquid to be placed in the containers, with consequent waste of containers and liquid.

A second type consists of filling machines featuring a flow meter, which have a system that controls a pneumatic piston tap that is electrically operated by an inline flow meter which measures the liquid to be dispensed. Also in this case, the system is efficient but expensive because the said system comprises delicate and sophisticated components which are particularly expensive.

In particular, drawbacks have been encountered with this type of filling machine when the product to be inserted is liquid or viscous, since the product is affected by pressure variations upstream of the tap . The variations mentioned are due to the fact that it is difficult to maintain a steady dispensing pressure.

Furthermore, a further drawback encountered consists of the fact that when the liquid is particularly viscous, the said liquid undergoes variations in density with the result that amount of the product introduced into the container may vary, preventing compliance with the required production parameters.

A third type of filling machine consists of piston filling machines . In this type of machine, a cylinder is filled with a product by suction and the said product is subsequently inj ected into the container as the piston lowers, sliding along a mechanical cam. The system just illustrated is economical to build but proves difficult to adj ust, as well as being inaccurate because, during the suction and dispensing phases, the said system may be influenced by external factors which modify the density and, consequently, the amount of the product handled.

In particular, this type of filling machine is scarcely functional when the product to be inserted is very liquid and foamy, as the filling step produces froth, which can leak out of the container, which therefore does not contain the correct or expected amount of liquid and consequently, must be discarded, resulting in increases in production costs.

As illustrated above, due to the presence of electric and electronic elements, the filling machines currently in use are particularly elaborate and the assembly thereof during construction is decidedly burdensome and demanding, but above all the said filling machines require complicated maintenance due to the replacement of components involving rather frequent and lengthy downtime for lines, which has repercussions for production times and in terms of the accuracy of the amounts of product dispensed and, therefore, contained in the containers.

Disclosure of Invention

The obj ect of the present invention is essentially to solve the problems of the prior art, overcoming the drawbacks described above by means of an automatic liquid filling device capable of offering great ease of use, notable safety, and accurate filling.

A second object of the present invention is to provide an automatic liquid filling device capable of filling a container with the maximum flow rate, reducing the said flow rate only in the final part of the filling.

Another obj ect of the present invention is to provide an automatic liquid filling device capable of being adapted to existing machines which have a tank and dispensing taps.

Another obj ect of the present invention is to provide an automatic liquid filling device which allows the size and the flow speed to be changed regardless of the pressure inside the product storage tank, the said device adapting to the size of the container neck.

Another obj ect of the present invention is to provide an automatic liquid filling device which is extremely reliable, features a small number of components, may be used for flammable and/or explosive liquids and does not require certification for the electrical components.

A further obj ect of the present invention is to provide an automatic liquid filling device which reduces the possibility of human error.

A further but not final obj ect of the present invention to provide an automatic liquid filling device which is easy to manufacture and works well, thereby containing production, management, and maintenance costs therefor.

These obj ects and others besides, which will become apparent over the course of the present description, are essentially achieved by means of an automatic liquid filling device as outlined in the claims below.

Brief Description of Drawings

Further characteristics and advantages will better emerge in the detailed description of an automatic liquid filling device according to the present invention, provided in the form of a non-limiting example, with reference to the accompanying drawings, in which:

figure 1 shows, schematically and from a partial sectional view, an automatic liquid fil ling device as per the present invention:

- figure 2 shows a schematic sectional view of a first component of the device in Figure 1 ;

Figure 3 shows a schematic sectional view of a second component of the device in Figure 1 ;

Fi gure 4 shows a schematic partial sectional view of an element of the device in Figure 1 ;

Figure 5 shows, schematically and in detail, a part of the element in Figure 4;

Figure 6 shows a schematic partial sectional view of a variant of the element of the device in Figure 4;

Figure 7 shows, schematically and in detail, a part of the element in Figure 6 ;

Figure 8 shows, schematically and in detail, a further part of the element in Figure 4. With reference to the figures, and in particular Figure 1 , 1 denotes, as a whole, an automatic liquid filling device according to the present invention.

Best Mode for Carrying Out the Invention

The automatic liquid filling device 1 essentially comprises a support structure 5 which is rotatably engaged with a parallelogram with bearings 4 which is connected to an upright 20, secured to one end of which there is a plate 2, which is envisaged to support a container 3 to fill, as shown in Figure 1 .

In particular, engaged with the parallelogram with bearings 4 on the opposite side to the upright 20, is a plate 40, on which a pair of contact elements 60 and 70 rest, the said elements being engaged with the respective shafts, each one of which being located inside a corresponding proportional valve 6 and 7.

In greater detail, each proportional valve 6 and 7 is engaged with the support structure 5 and is essentially constituted of a hollow shaft 65 and 75 , at one end of which the respective contact element 60 and 70 is envisaged, while at the other end of which a small chamber 61 and 71 is envisaged, which is inflated by air which creates a pressure level which varies according to the amount of liquid in the container, as will be explained better later on. Indeed, as the weight of the container 3 increases due to the liquid entering proportionally, the air flow through the proportional valve gradually decreases to zero.

As illustrated above, the two valves 6 and 7 are structurally the same, but work in inverse manner. Indeed, in the present embodiment, the proportional valve 7 manages the air inlet while the valve 6 manages the outlet. In greater detail, when the liquid enters the container 3 , the latter increases in weight and presses on a weighing unit 8 1 present in the parallelogram with bearings 4 and the more the weight increases, the more the valve 7 opens and the more the air flow through a contractile linear actuator 9 decreases, with the consequence of gradually decreasing the amount of liqui d dispensed into the container to zero.

In the present embodiment, a first pipeline 72 branches off from the valve 7 and is connected to a "tap" 140 featured to manually adj ust the opening speed of a shutter 1 1 . Furthermore, a second pipeline 73 branches off from the valve 7 and is connected to a pressure regulator 1 7 whose task is to manage the response of the weighing unit according to the load.

Indeed, when the container 3 is filled, the plate 40 exerts an upward thrust action against the shaft 65 of the valve 6, the shaft rises resulting in the valve venting more air via an opening 66 featured for the venting of air during container filling and, consequently, less air reaches the contractile linear actuator 9.

Indeed, the more liquid is present in the container and the less air reaches the contractile linear actuator 9 and the more liquid in the container the more air vented via the opening, 66 in inversely proportional manner. In this way, by properly adj usting the two shafts of the valves 6 and 7, perfect balance/operation is achieved.

In addition to the explanations so far, a first pipeline 62 branches off from the valve 6 and is connected to the contractile linear actuator 9 and likewise a second pipeline 63 branches off, which is connected to the pressure regulator 17.

As mentioned earlier and shown in Figure 3 , the valve 6 features a sliding, hollow shaft 65 envisaged for the passage of air from the pipeline 63 and from the chamber 61 , which has a T-shaped conformation. The pressure exerted by the air is envisaged to create resistance to the pressure of the element 60.

Furthermore, the said shaft 65 features, at the lower end thereof, an adjustment pin 6b which comes into contact with a magnet 6c, envisaged to keep the said shaft in its seat and balanced.

In addition, the shaft 65 is integral with the element 60, as shown in Figure 3.

In particular, the shaft 65 features, on the external surface thereof, a series of circular grooves 67 , arranged perpendicular to the axis of the shaft and envisaged to allow the gradual passage of air from the pipeline 62 to a release opening 66.

Similarly, and as already mentioned, the valve 7 also features a structure similar to the valve 6, as shown in Figure 2.

Indeed, as shown in Figure 2, the said valve 7 comprises the sliding hollow shaft 75 envisaged for the passage of air from the pipeline 73 and from the chamber 7 1 , which also has a T-shaped conformation, and the pressure exerted by the air is envisaged to create resistance to the pressure of the element 70.

Furthermore, the said shaft 75 features, at the lower end thereof, an adj ustment pin 7b which comes into contact with a magnet 7c, envisaged to keep the said shaft in its seat and balanced. Also in this case, the shaft 75 is integral with the element 70, as shown in Figure 2.

Furthermore, the shaft 75 features, on the external surface thereof, a series of circular grooves 77, arranged perpendicular to the axis of the shaft and envisaged to allow the gradual passage of air from the pipeline 72 to the contractile linear actuator 9.

In accordance with the present invention, engaged with the support structure 5 is a horizontal support 50, from which a vertical support 5 1 branches off, the latter being envisaged to support the contractile linear actuator 9 which operates by means of the pressure of the fluid present therewithin. The tap 140 is featured to adj ust the opening speed of the shutter 1 1 , as will be better illustrated later on.

In addition to the explanations so far, at the free end of the horizontal support 50, there is a three-way pneumatic valve 12 engaged, the said valve being equipped with a control wheel 120, to actuate a valve 1 3 which is envisaged to manage the passage of a flow of air into the proportional valve 7 through a pipeline 1 30.

Furthermore, below the horizontal support 50 a pipe 1 4 is featured, which is connected, at one end, to a tank containing the product to dispense and, at the other end, to a dispenser 1 5 , which is equipped, internally, with a cylindrical choke 1 6 for the gradual inlet of the liquid into the container J .

In greater detail, the said cylindrical choke 1 6 features a sliding shaft 1 60 which is integral with the cylindrical choke 1 6 and is equipped with a tap, which is simply the shutter 1 1 . In particular, the said cylindrical choke 1 6 comprises a sliding bushing 1 61 , shown in Figure 8, which is inserted between the sliding shaft 1 60 of the shutter 1 1 and a protection element 162 constituted of a protective rubber element designed to prevent the liquid seeping out from the horizontal support 50, as shown in Figure 4 .

As mentioned earlier, the automatic liquid filling device comprises the first pressure regulator 17, envisaged to operate at a pressure range of 0 to 6 bar and to select the amount of the product to be dispensed into the container, and comprises a second pressure regulator 1 8 , which is also designed to operate with pressure levels ranging from 0 to 6 bar to vary the maximum opening of the shutter 1 1 and, consequently, the amount of liquid running through the product flow line denoted 200 in Figure 1 .

In addition to the explanations so far, when filling containers with a liquid which does not produce froth, a first choke 165 is employed, as shown in detail in Figure 5 , which has straight recesses 1 65a to ensure a direct flow of the liquid.

In the event, meanwhile, of filling containers with a l iquid which froths, a second choke 1 66 is employed, as shown in Figure 6 and in detail in Figure 7, which directs the liquid so that the liquid flows down into the container following the inclination of the recesses 166a, twisting the flow of the said liquid and reducing the speed of descent thereof, so as to reduce the amount of froth produced and present in the container.

After the predominantly structural description, the invention in question will now be outlined.

When a container is to be filled, an operator simply has to manually press the wheel valve 12, or manage the same operation by means of an automatic device, as a result of which the valve 13 is actuated and allows a flow of air to pass into the proportional valve 7, which creates a predetermined pressure in the contractile linear actuator 9. Upon contracting, the contractile linear actuator 9 opens the shutter 1 1 and, at the same time, presses the wheel valve 12, keeping the system stable with the shutter open with the result that the liquid descends into the container at a predetermined rate of flow 1 65. When the weight of the plate 2 approaches, by means of the parallelogram 4, the predetermined weight, the plate comes into contact with the contact element 70 on the proportional valve 7, which intervenes to decrease the flow of air to the contractile linear actuator 9, while increasing, at the same time, the venting of air through the opening 66 in the valve 6.

The staggered heights of the two shafts 65 and 75 is envisaged in order to be able to appropriately adjust the system; indeed, the descending flow of liquid into the container, which is at the maximum level at the moment of opening, is gradually decreased by the cylindrical choke 1 6 on the flow line 200 towards the end of the filling step, with the amount of liquid entering the container decreasing once the shutter closes completely following release of the wheel valve 1 2, which closes the valve 13 and thus guarantees a certain accuracy and replicability of the weight in the container, as well as smaller amount of froth in the event that the liquid is frothy.

At this point, the pressure regulator 1 7, acting on the different elasticity of the shafts of the valves 6 and 7, will vary the amount of liquid to be placed in the container.

Thus the present invention achieves the aims set. The automatic liquid filling device envi saged in the present invention offers great ease of use, notable safety, and accurate filling.

Advantageously, the automatic liquid filling device in question allows a container to be filled with the maximum flow rate, reducing the said flow rate only in the final part of the filling, thereby preventing accidental leakage of the liquid or froth, for frothy liquids. In this way, when containers are filled with liquids that produce froth, the froth is reduced and leakage avoided, as well as the fact that a particular choke is used which, by twisting the liquid, slows down the speed thereof, consequently limiting the formation of froth.

In particular, the automatic liquid filling device guarantees adaptability to existing machines, provided that the latter are equipped with a tank and dispensing taps.

A further advantage of the device according to the present invention is that the size and the flow speed may be varied regardless of the pressure inside the product storage tank, the said device adapting, therefore, to the size of the container neck.

Advantageously, the present device is particularly suitable for filling containers with flammable and/or explosive liquids and since there are no electrical components there is no risk of contact, possible sparks, etc. The device according to the present invention may operate without the specific certifications relating to the electrical components which are compulsory in the current devices according to the prior art for these types of liquid. In addition to the explanations so far, the device in question is extremely reliable, comprises a smaller number of components, does not require particular maintenance and replacement of components, and prevents the system downtime that occurs with filling machines according to the prior art.

Moreover, the device in question is structurally simple and very functional and has contained production, management, and maintenance costs .

A further but not final advantage of the present invention is that said system proves to be remarkably easy to use and structurally simple, and works well.

Naturally, further modifications or variants may be applied to the present invention while remaining within the scope of the invention that characterises it.