The present invention relates to a filter designed for use in association with wine-making apparatus such as fermenters and the like, to separate the marc from the must during the pumping-over and final draining of the wine.

The filter in accordance with the invention comprises a box-shaped body, the walls of which consist of a grid and means which exit from the inside of the body through the said grid to remove and detach the marc that tends to flow towards the pipe through which the must rises to the upper chamber of the wine-making unit.

The filter is designed to be used in association with wine-making apparatus such as fermenters and the like, and the invention also relates to a wine-making unit fitted with the said filter.

One stage of the wine-making process involves fermentation of the must in suitable containers, into which the must is introduced together with the marc.

The marc tends to rise to the surface, forming a "cap" which must be periodically moistened with must, firstly to prevent the marc from deteriorating on contact with the air and initiating an acetification process, and secondly to allow the dyes present in the marc to dissolve thoroughly.

The most recent types of apparatus used for fermentation comprise a container divided into two chambers, one above the other, the lower chamber being designed to receive the must and the marc, while part of the must is transferred at intervals into the upper chamber, and then spills into the lower chamber where it moistens the marc.

European patent application number 0.959.127, filed by the present applicant, describes a wine-making unit which comprises a container divided into two chambers, one above the other, a first pipe which connects the upper chamber with the lower part of the chamber below, a second pipe fitted with valve-type opening and closing means which connects the upper parts of the said two chambers, and means designed to open a passage in the partition wall between the said chambers to allow the must in the upper chamber to spill into the chamber below.

In this type of wine-making unit, the pressure created by the carbon dioxide developed in the must is usually exploited to perform the pumping-over stage, forcing the must along the pipe that leads from the bottom of the lower chamber to the upper chamber.

A filter designed to prevent the marc from being drawn into the upper chamber by the must needs to be fitted at the inlet of this pipe.

The said filters are usually constituted by a cylindrical body with a plurality of holes or slits through which the must can pass.

To remove the marc which adheres to the surface of the filter and clogs these openings, known filters contain devices which cause systems such as scrapers made of rubber, teflon and the like to travel along the walls in order to detach the marc and clear the passage.

FR-A-2.612.080 describes a filter for wine lees comprising a filter cylinder provided with a feed conduit at one of its ends and a discharge opening at its opposite end.

A series of rollers and of helical scrapers, the leading face of which points towards the discharge opening, are mounted on radial arms fitted on a central rotating shaft, and press against the inner face of the filter cylinder, engaging the marc from the inside of the filter to remove it from the walls.

However, these known systems are not entirely problem-free because the said blades or scrapers, made of various materials, tend to compress the marc which has not been detached from the filter and force it into the said holes, thereby clogging them.

In time, these known filters therefore tend to clog or otherwise lose their efficacy.

The present invention, which offers a filter for wine-making apparatus able to solve the problems described above, falls into this sector.

The said purpose is achieved by a filter constituted by a box-shaped body, the walls of which contain a plurality of slits for the passage of must, and a rotating shaft integral with a plurality of blades inside the said box-shaped body; as a result of the rotation of the shaft, the said blades exit through the said slits, mechanically removing the marc adhering to the filter walls.

The mechanical action of these cleaning devices is thus performed in the opposite direction to that of known filters, as these devices engage the marc, pushing it away from the filter walls.

This invention will now be described in detail, by way of example but not of limitation, by reference to the annexed figures wherein:

• figure 1 schematically illustrates a wine-making unit equipped with a filter in accordance with the invention
• figures 2, 3 and 4 are the side view, front view and view from above respectively of a filter in accordance with the invention, fitted inside a wine-making unit
• figures 5 and 6 illustrate another embodiment of the filter in accordance with the invention, during the various cleaning stages.

In figure 1, no. 1 indicates the wine-making apparatus, which comprises a lower chamber 2 into which the must is introduced with the marc, an upper chamber 3, separate from the preceding one, in which part of the must, due to the effect of the pressure developed by the carbon dioxide, rises through a pipe 4, at the inlet of which a filter, shown as no. 5 in figure 2, is fitted. No. 6 in figure 1 indicates an electric control board which comprises (inter alia) a PLC designed to control the functions of the various devices present in the unit.

The filter (see figures 2 to 4) comprises a box-shaped body 7, the walls of which contain a plurality of slits 8, through which the must penetrates and then exits from the filter through a connector 9 which leads to pumping-over pipe 4. The latter may be fitted with a valve 14 connected to devices designed to introduce a pressurised gas to oxygenate the must.

In the embodiment illustrated in the figure, the filter has a pair of side walls which are convex or have a similar configuration.

A pair of opposite walls of box-shaped body 7 are fitted with a shaft 10 which continues to the outside of chamber 2 of the wine-making unit, passing through walls 11 thereof. A pneumatic motor 13 controls the rotation of shaft 10 around its own axis.

A plurality of arms 12 in the form of blades which exit from the box-shaped body through slits 8 are fitted to shaft 10.

The motor, controlled by the PLC, rotates the shaft with reciprocating motion, causing blades 12 to travel along the whole length of the corresponding slits and remove the marc.

Blades 12 will preferably be lance-shaped or have a curved edge so that when they are made to rotate by shaft 10, the edge of the blade always engages the parts that adhere to the filter, and removes them.

This solution is far more effective than those now known, because the blades engage the marc from the inside to the outside of the filter, thus tending to move it away from the filter rather than pressing it against the filter.

The PLC can be programmed to perform this operation automatically at pre-set intervals, thus constantly ensuring the perfect efficiency of the filter without the risk of clogging.

In accordance with another preferred embodiment of the invention illustrated in figures 5 and 6, a plurality of pairs of blades 15 slide inside box-shaped body 7; each blade is fitted with a pin 16, which said pins slide inside slots 17 cut into a series of plates 18 fitted to shaft 10.

Slots 17 are shaped like the profile of a cam which, as a result of the rotation of plates 18, acts on pins 16, causing them to slide together with blades 15, so that the said blades move from a position in which they are fully retracted inside box-shaped body 7 (figure 5) to a position (illustrated in figure 6) in which their outer edge exits from the box-shaped body, passing through slits 8 in opposite walls 19 and removing the marc that adheres to the filter.

An expert in the field could devise various modifications and variations, all of which should be deemed to fall within the ambit of this invention.