Description

DEVICE FOR DOSING PREDETERMINED PORTIONS OF A PASTY

PRODUCT

Technical Field

The present invention relates to a device for dosing predetermined portions of a pasty product to be packaged in a suitable wrapper, in particular a foodstuff such as processed cheese, a stock cube and other products.

Background Art

There are prior art devices for dosing predetermined portions of a pasty product, in particular a processed cheese, which comprise a product collection hopper, connected to a dosing piston which moves with reciprocating motion from a back position, in which a dosing chamber is filled, to a forward position for dispensing a predetermined portion of product.

In the prior art devices, the pasty product is usually fed into the collection hopper through pumping means. Inside the collection hopper the pasty product is kept suitably moving to guarantee that the product being processed retains a uniform density. However, such a dosing system is too bulky, requiring the use of a special product homogenisation hopper.

Moreover, according to another disadvantageous aspect of the prior art systems, the dosing piston must be alternately put into communication with the loading hopper and with the outfeed opening. The result is dosing in which the working cycle of the dosing means must be divided between the two above- mentioned operations, which may make the dosing operation too slow.

According to another negative aspect, it is not possible to use the prior art pasty product dosers to correct the weight of the individual portion of product which is dispensed by the dosing device. According to yet another disadvantageous aspect of the prior art dosing

devices, in the final step of dispensing the pasty product portion dosed, in particular when dosing processed cheese, filaments or burrs of product remain attached to the doser body at the opening where the product comes out, then drop off and make the machine dirty, with serious disadvantages in terms of machine hygiene and cleanliness. Moreover, said filaments or burrs inappropriately dispensed by the prior art dosers do not allow the obtainment of portions with a predetermined weight, the weight not being as precise as required.

Disclosure of the invention According to an advantageous aspect, a device is provided for dosing predetermined portions of a pasty product to be packaged, in particular a foodstuff such as processed cheese, a stock cube and other products, comprising a product dosing chamber having a product infeed opening and a product outfeed opening and means for dispensing a predetermined portion of product from the outfeed opening, characterised in that the dispensing means comprise a product screw feeder.

In this way, it is possible to obtain a simplified structure for the dosing apparatus.

Moreover, there is also the possibility of practically simultaneous communication between the dosing means and the product loading opening as well as the product outfeed opening, with a consequent advantage in terms of operating speed.

Brief Description of the Drawings The technical features of the device are apparent from the detailed description which follows, with reference to the accompanying drawings, which illustrate a preferred embodiment of the invention provided merely by way of example without restricting the scope of the inventive concept, and in which:

Figure 1 is a schematic cross-section of a preferred device made in accordance with the present invention, in a product unloading condition;

Figure 2 is a schematic cross-section of a preferred device made in accordance with the present invention, in a condition in which the unloading opening is closed.

Detailed Description of the Preferred Embodiments of the Invention

The Figures show how a preferred embodiment 10 of a device for dosing predetermined portions of a pasty product to be packaged, in particular for dosing a foodstuff such as processed cheese, a stock cube and other products, comprises a body 11, forming a cylindrical product dosing chamber 12, having an infeed opening 14 for a product arriving (as shown by the arrow "A") from a respective pipe 15, which is connected to a suitable pasty product feed pump (not illustrated in the accompanying drawings), and a lower outfeed opening 16 for a predetermined portion of the product. hi the present device there are advantageous means for dispensing the predetermined portion of product from the outfeed opening 16, the means for dispensing or propelling the product outside the device comprising a rotatable product screw feeder 18. hi practice, as they feed the product, the product dispensing means form means for defining the predetermined portion to be expelled from the device. As illustrated, the screw feeder 18 has a central shaft 20 and a product pusher blade 22, rotationally driven by a suitable gearmotor 24, suitably controlled.

By making the screw feeder 18 rotate through a predetermined number of revolutions, or part of a revolution, a predetermined desired quantity of product P comes out, to be wrapped in a suitable folded wrapper 26, supported by corresponding supporting means or a supporting cavity 28.

Moreover, advantageously there are also means for compensating the product pressure in the dosing chamber 12, regularising the inconstant pressure provided by the means which pump the product into the dosing chamber 12.

In this way, it is possible to obtain particularly precise dosing of a predetermined quantity of product.

The compensation means, in the dosing chamber 12, are in the form of product compression means 30, designed to apply a predetermined pressure to the product in the dosing chamber.

In particular, the compensation means advantageously comprise a piston 30 able to move in a corresponding chamber 32, in communication with the dosing chamber 12 through an opening 34.

In practice, as illustrated, the compensation opening 34 in the doser body 11 is at the same level, lengthwise, as the infeed opening 14, that is to say, put another way, it is on the side of the doser body 11 opposite that in which the infeed opening 14 is made.

Advantageously, the opening 34 for communication between the compensation sub-chamber 32 and the dosing chamber is close to or at the opening 14 for product infeed into the dosing chamber 12.

Advantageously, there are means for adjusting the position of the compression means 30, depending on the density of the product fed. The means for adjusting the position of the compression means 30, in particular the longitudinal position of the compression means in the chamber 32 (as illustrated by the arrow B in Figure 1), comprise a corresponding pneumatic cylinder, or actuator, not illustrated in detail.

According to another embodiment, not illustrated in the accompanying drawings, in place of the compensation piston 30, a movable elastic membrane may be used, pressing against the product arriving from the product feed pump.

Obviously, there are end of stroke sensors for the piston 30 forward and backward movements, to stop the system if faulty operating conditions arise. In practice, the end of stroke sensors are able to switch off the product feed pump if the end of stroke is exceeded, or to switch the feed pump back on as soon as the compensation means return from said end of stroke position to a normal operating condition.

To prevent an unwanted quantity of product from coming out, at the end of the dosing operation, advantageously, there are means for closing the product outfeed opening 16.

Advantageously, said closing means 36 are supported by the product dispensing means and consist of a pin or needle 36, designed to be inserted in the product outfeed opening 16. In particular, as illustrated, the pin 36 is supported at the end of the dosing screw feeder shaft 20. The product dispensing means are therefore able to move between a back position and a forward position in which the product outfeed opening 16 is closed.

In practice, the screw feeder 18 is connected to a block driven by a movable arm 38, as indicated by the bi-directional arrow F, which moves the screw feeder downwards to close the opening 16, then, upwards to return the screw feeder to the normal raised dosing position, in which the opening 16 is open and allows the product to pass freely.

The pin 36 for closing the outfeed opening 16 is advantageously capable of rotary motion, corresponding to that, indicated by the arrow "R", of the screw feeder shaft 20 on the extension of which the pin 36 is positioned, allowing it to achieve better breakage of the "filament" of pasty product, such as processed cheese.

According to another advantageous aspect, suitable sensor means may be used to detect the weight of the predetermined portion of product in the wrapper 26. Said sensor means are operatively connected to the dispensing means, in particular to the gearmotor 24, so as to vary the screw feeder 18 rotation driven by the gearmotor. In this way, it is possible to always dose the desired quantities of pasty product.

As illustrated, in the extended dosing chamber 12 there are corresponding heating elements for the product P to be dispensed, designed to keep it in an easily dosed fluid state. As illustrated, the product heating elements are labelled 39 in the drawing.

The dosing chamber 18 also comprises an end portion, or cap 40, on which the product dispensing opening 16 is located and which is removably connected to the body 11 by corresponding means 42.

Advantageously, the cap 40 may be removed, or opened, to allow access to the dosing chamber 12 and washing to clean and disinfect it.

Obviously, it shall be understood that, in contrast to what is described above, to close the opening 16 with the pin 36, the cap 40 could be moved towards the screw feeder 18.

The invention described above is susceptible of industrial application and may be modified and adapted in several ways without thereby departing from the scope of the inventive concept. Moreover, all the details of the invention may be substituted by technically equivalent elements.