Sterilizing Device for an Ice-Cream or Similar Delivering Machine

1. Field of the Invention

The present invention relates to machines for making ice-cream or whipped cream in a short time (so-called "espresso" machines) and concerns a device for improving the storage conditions of the food mixture in the machine and at the outlet holes of the delivery tap.

2. Description of the Prior Art

Generally, in the whipped cream and espresso ice-cream machines, the food mixture is stored in the liquid state in proper refrigerated containers or in reservoirs inside a refrigerated cell.

In both cases, the mixture is protected from the external environment by lids (in the case of refrigerated containers) or doors (in the case of the refrigerated cell).

In spite of this protection, the exposed surface of the mixture in the container or in the reservoir is in contact with the air trapped under the lid or in the refrigerated cell. This air from the external environment could be polluted and contaminate the mixture leading to an increase in the quantity of bacteria in the mixture itself. In such a case, all the effort to store the mixture under optimum hygenic conditions, i.e. scrupulous cleaning of the machine, loading with pasteurized product and rigorous control of the storage temperature, would all be in vain.

Further, these machines have delivery taps for the product mounted externally on the machine, easily accessible to the user. Such a delivery tap is connected to the whipping cylinder the whipped cream or to the mixing cylinder of the espresso ice-cream machine, and, after the first delivery, always remains in contact with the product, so that after every delivery some product in the area of said delivery tap remains in contact with the outside environment.

In this portion of the product, despite closing any doors which form a barrier between the tap and the outside environment, the quantity of bacteria increases rapidly, and if the deliveries are not very frequent, this quantity of bacteria tends to contaminate the product inside the tap as well. In this case the user is forced to throw away the first portion of the delivery in order to avoid the risk of giving the consumer a contaminated product.

An object of the present invention is to provide a device which improves the storage and/or delivery conditions of the mixture in machines of the type described, preventing the air present inside the refrigerated cell from contaminating the same mixture, and/or storing both the product in the delivery tap and inside the delivery tap under the best conditions of hygiene, even for extended periods of time between one delivery and the next.

This object is achieved by a device characterized in that it consists of at least one ultraviolet lamp or one supply of ozone, located inside the storage compartment and/or delivery area of the mixture and preferably activated every time the area is closed to the external environment.

The device according to the invention providea a rapid sterilization of the air enclosed in the mixture storage and/or delivery area, preventing any contaminating substances in the air from polluting the mixture itself. Further, providing for intermittent operation of the UV light or ozone supply, the air in the storage area is kept sterile even in the case of any infiltration of air from the outside, further increasing the guarantee of good storage of the mixture.

As far as the delivery area is concerned, the user should close the door after every delivery, automatically operating the UV light or the ozone supply over the opening of the delivery tap or taps, so that the product remaining in contact with the delivery tap or taps is maintained under the best conditions even for a prolonged period.

Further, air trapped inside the door, including that which inevitably tends to infiltrate from outside, is sterilized and maintained thus by the lamp or by the supply of ozone, a further guarantee of the good storage of the product.

The characteristics and details of the device according to the present invention shall now be described in detail with reference to the attached drawings, in which:

FIG. 1 illustrates the device installed inside a refrigerated cell of an espresso ice-cream machine.

FIG. 2 illustrates the device applied to the delivery area of an espresso ice-cream machine.

With reference to FIG. 1 of the attached drawings, a so-called espresso ice-cream machine 1 contains a refrigerated cell 2 inside which are located one or more reservoirs 3 containing the mixture to be frozen in the liquid state. Such a mixture is kept at a temperature of about -4 C. and is fed to a refrigerated mixing cylinder 8 above the cell 2. To this end a pump 9 is provided to take the mixture from the reservoir 3 to the mixing cylinder 8.

There are usually agitation devices 6 inside the reservoirs which prevent the precipitation of the fats and their deposit on the bottom of the same reservoir.

The cell 2 is closed by a door 4 with an airtight seal.

As stated above, despite closing this door, rigorous checks of the internal temperature of the cell and compliance with all the rooms of the hygiene and cleaning regulations of the machine, the air trapped inside the cell by each new closing of the door could contaminate the mixture and promote the growth of bacteria.

In fact, the air inside the cell comes from outside, and being in contact with the surface of the mixture in the reservoirs, could very easily contaminate it.

With the object of sterilizing the air present in the cell and eliminating all possibilities of contamination of the mixture, at least one ultra-violet light 5 is fitted inside the cell which can light all the area inside the cell. This lamp is switched on every time the door is closed. A timer 7 is preferable to switch off the lamp 5 after a certain period and to switch it on again at regular intervals.

In this way any infiltration of air from outside is neutralised and the air in the cell is kept at optimum hygienic conditions.

The UV lamp 5, beside sterilizing the air inside the cell, irradiates the surface of the mixture. Providing there is adequate circulation of the mixture in the reservoirs 3 so that the surface layer is continually changed, it is possible to sterilize a mixture by UV irradiation.

As an alternative to the UV light, and always with the objective of sterilizing the air inside the cell, a supply of ozone can be arranged, activated for a certain period of the closing of the door.

In FIG. 2, the delivery tap 11 of an espresso ice-cream machine consists of a number of delivery pipes 12, each of which is controlled by a lever 13. The delivery tap 13 can be dismantled easily for cleaning by turning the screws 14. The lower part of the taps can be sealed off by a door 15 which is a barrier between the delivery area and the outside. Corresponding to the taps in the delivery area there is a UV light 16 turned towards the delivery outlets 12. The lamp 16 is located within the area protected by the door 15 and is switched on by a switch 17 actuated in its turn by the door 15. In this way, at the end of every delivery, the user closes the door which, acting on the switch 17, turns on the light 16. The ultra-violet rays irradiate and sterilize all the delivery area enclosed by the door and reach the product present in and around the outlet holes of the pipes 12 preventing the growth of bacteria therein.

Instead of the ultra-violet ray lamp, the device according to the invention can have an ozone supply having its outlets directed towards the outlet holes of the delivery taps. In this case the supply of ozone is initiated by a switch every time the door is closed and acts as a sterilizer of the interior of the compartment and prevents the growth of bacteria in the product remaining in the outlet holes of the delivery pipes.

The device is shown in an embodiment for an espresso ice-cream machine, but it can be advantageously applied to a machine for whipped cream. Further, it can be applied alternatively, or jointly in the storage area and delivery area of the mixture.