MXPA00005207A - Three-way antimix valve for a pourable food product packaging machine - Google Patents

Abstract

A three-way antimix valve (1) for a pourable food product packaging machine, the valve having a casing (2) in turn having a lateral wall (4) which defines a cavity (6) having an axis of symmetry (A) and communicating with a bottom drain opening (7), and has three gates (10, 11, 12) spaced 90 DEG apart;and a rotary shutter (3) housed inside the cavity (6), rotating about the axis (A), and having a lateral surface (20) in which are formed two openings (22, 23) spaced 90 DEG apart and communicating with each other via an inner passage (24) for connecting respective pairs (10,12;11,12) of gates in two respective work positions (a, b) of the shutter (3);the casing (2) has two recesses (17, 18) spaced 90 DEG apart and each located in an intermediate position between a respective pair (10,12;11,12) of gates;and the shutter (3) has four recesses (25, 26, 27, 28) spaced 90 DEG apart, and one (25) of which is located between the two openings (22, 23) to connect the passage (24) and the three gates (10, 11, 12) to the drain opening (7) in an intermediate position (c) of the shutter (3).

Description

ANTIMEZCLA TRIDIRECCIO? AL VALVE FOR A PACKAGING MACHINE OF FOOD SAFETY PRODUCTS DESCRIPTION OF THE INVENTION The present invention is concerned with a three-way non-mixing valve for a packaging machine for pourable food products. The machines for packaging pourable food products, such as fruit juice, wine, tomato sauce, pasteurized milk or long-term storage (UHT) etc., are known, in which packages are formed from a continuous tube of packaging material defined by a longitudinally sealed strip. The packaging material has a multilayer structure comprising a layer of paper material covered on both sides with layers of heat sealing material, for example polyethylene. In the case of aseptic packages or packages for long-term storage products, such as UHT milk, the packaging material consists of a layer of barrier material defined for example by an aluminum film, which is superimposed on a layer of material plastic heat seal and is in turn covered with another layer of heat sealing plastic material that inevitably defines the inner side of the package that comes into contact with the food product.

REF .: 119132 To produce aseptic packages or packages, the strip of the packaging material is unwound from a reel and fed through a sterilization unit in which it is sterilized, for example by immersion in a bath of liquid sterilizing agent, such as a concentrated solution of hydrogen peroxide and water. More specifically, the sterilization unit comprises a full bath, in use with the sterilizing agent in which the strip is fed continuously and an aseptic chamber in which the strip of packing material leaving the sterilizing bath is treated to separate any agent residual sterilant, for example by drying rolls and sterile air jets at high temperature. Before leaving the aseptic chamber, the strip is folded to a cylinder and longitudinally sealed to form in a known manner a longitudinally, vertically, continuous sealed tube. The tube of packaging material in effect forms an extension of the aseptic chamber and is continuously filled with the product that can be poured and then fed to a forming and sealing unit (transverse) to form individual packages and by this the tube is clamped between pairs of jaws to seal the tube transversely and form aseptic pads packages. The pads packs are separated by cutting the sealed portions between the packs and then fed to a final folding station where they are mechanically folded to the finished shape. In known machines of the type described briefly above, the tube of packaging material is continuously filled by a conduit forming part of a circuit for supplying the pourable food product for packing (hereinafter referred to simply as the "packaging circuit"). product "). The circuit of the product must be sterilized with aseptic air before the start of each cycle of processing and washing with a liquid solution at the end of the work cycle; for which purpose, the product circuit must therefore be selectively connected to a wash solution supply circuit and a sterile air supply circuit by means of a switching assembly to prevent mixing of the various fluids and any traces of the wash solution in the product due to imperfect sealing. For safety reasons and to ensure sterility of the product circuit, the product circuit is normally connected to the switching assembly by means of a service conduit equipped with an aseptic, bidirectional on-off valve, for example steam barrier . Substantially two switching assembly design solutions are known.

The first is simply to use a movable attachment permanently connected to the product service pipeline and having connection means for a selective connection to the supply circuits of the washing solution and sterile air. Although it is direct and cheap, this solution has the disadvantage of manually switching from one working stage to the other, by physically disconnecting and reconnecting the movable accessory to the relative circuits. A second known solution consists of using three three-way valves, each of which has a pair of gates connected to a respective pair of circuits and a third gate connected to a drain pipe to drain any leakage from the valve and thus prevent leaks undesirable caused by pressure on the seals of the other valves. Although it allows automatic switching, this second solution is expensive and involves considerable load losses. It is an object of the present invention to provide a tridirectional anti-mixing valve designed to eliminate the aforementioned disadvantages commonly associated with known switching assemblies. According to the present invention, there is provided a tridirectional anti-mixing valve for a pourable food product packing machine, the valve comprises a box having a side wall defining a cavity having an axis of symmetry and communicating with a drainage opening of the lower drainage bottom or opening and a rotary plug that rotates about the shaft and lodged in the cavity with a respective lateral surface cooperating fluid-tightly with the side wall of the casing; the box has a first gate and a second gate, both formed in the side wall and angularly spaced by a first angle and a third gate formed in the side wall in an intermediate position with respect to the first and second gate and angularly spaced with respect to to each one by a second angle equal to half of the first angle; the rotating shutter has a first and a second opening, both formed on the side surface and spaced angularly by an angle equal to the second angle and an internal passage connecting the first and second openings; the side wall of the box has two internal recesses or recesses formed respectively between the first gate and the third gate and between the second gate and the third gate; the rotary shutter comprises at least three recesses or recesses, of which a first recess or recess is formed between the first and second opening, a second recess or recess is formed on the opposite side of the second opening with respect to the first recess or recess and angularly spaced with respect to the first recess or recess by an angle equal to the second recess and a third recess or recess is located on the opposite side of the first recess with respect to the first recess or recess and spaced with respect to the first recess or recess by an angle equal to the second angle; the recesses or recesses of the box and the recesses or recesses of the rotary shutter communicate with the drainage opening of the bottom of the box; the valve comprises drive means for moving the rotary shutter between a first working position in which the first and second opening of the rotary shutter respectively communicate with the first gate and the third gate of the box, an intermediate position in which the first and second openings of the rotating shutter communicate with respective recesses or recesses of the box and the first, second and third doors of the box communicate with respective recesses or recesses of the rotary shutter and a second working position in which the first and second opening of the rotary shutter communicate respectively with the third gate and the second gate of the box. A preferred non-limiting embodiment of the present invention will be described by way of example only with reference to the accompanying drawings, in which: Figure 1 shows a perspective view of a valve according to the present invention; Figure 2 shows a cross-sectional view of the valve of Figure 1; Figure 3 shows a section along the line III-III in figure 2. The number 1 in the attached drawings indicates as a whole a three-dimensional anti-mixing valve for a machine (not shown) for packing pourable food products . The valve 1 consists substantially of an external box 2 having an axis A and a rotary plug 3 housed in the box 2 and which rotates about the axis A. The box 2 substantially comprises a side wall 4 having a tapered internal surface 5 tapering downwards and defining a cavity 6 communicating externally via a drainage opening 7 of the bottom or lower drainage opening. Box 2 also comprises a top cover 8 fitted to an upper annular flange 9 of the side wall 4. The side wall 4 (figure 2) comprises three through openings or substantially circular gates , 11, 12 in which the respective connection conduits 13, 14, 15 originate. More specifically, the gates 10 and 11 are diametrically opposite and coaxial with each other (that is, the respective axes form a central angle alpha of 180). degrees) and are connected by respective connecting conduits 13, 14 to a sterile air supply circuit (not shown) and to a liquid wash solution supply circuit (not shown); while the third gate 12 is located at an intermediate position with respect to the gates 10, 11, to form with each a central angle beta of 90 degrees and is connected by the respective connection conduit 15 to a service duct that forms part of a circuit for the pourable food product for packaging and which is equipped with an additional on-off valve (not shown). The side wall 4 also comprises two recesses or recesses 17, 18, which are defined by cylindrical, concave bottom grooves, with generating lines parallel to the axis A, which respectively extend between the gates 10 and 12 and the gates 11 and 12 along respective generation lines of the inner surface 5 of the side wall 4 and communicating with the lower drainage opening 7. The plug 3 comprises a conical lateral surface 20 cooperating in a fluid-tight manner with the inner surface 5 of the side wall 4 of the box 2 under a spring 21, as described in detail hereinafter. The obturator 3 comprises a first opening 22 and a second opening 23, both formed on the lateral surface 20, separated by 90 degrees with respect to each other and connected to each other by an elbow passage 24 (figure 2) that defines a curve 90 degrees The obturator 3 also comprises 4 recesses or recesses 25, 26, 27, 28 equally spaced angularly and extending along respective generation lines of the lateral surface 20. Like the recesses or recesses 17, 18, the recesses or recesses 25, 26, 27, 28 have cylindrical bottom surfaces with generation lines parallel to the axis A and communicating with the drainage opening 7 of the bottom of the box 2. More specifically, the recess 25 is located between the openings 22 and 23; the recesses 26 and 27 are located on opposite sides of the respective openings 22 and 23 with respect to the recess 25 and the recess 28 is diametrically opposite the recess 25. The passage 24 (figure 3) is conveniently inclined from a respective intermediate portion towards the recesses. openings 22, 23, to improve the drainage of liquid into the passage to the openings 22, 23. The shutter 3 is conveniently made of a good sealing polymer with a low coefficient of friction to improve the rotation under load of the shutter 3 to the inside box 2, for whose purpose, PTFE-based composites can be conveniently used, such as Rulon® J manufactured by FURON COMPANY, Laguna Niguel, CA (U.S.A.). The valve 1 also comprises a disc 35, of axis A, to drive the obturator 3 and which rests on an upper face 36 of the obturator 3 and is angularly connected to the obturator 3 by means of teeth 37 of two faces extending downwards from the disc 35 and engaging respective seats 38 formed on the face 36 of the obturator 3. The disc 35 has an axial control shaft or shaft 39 that extends integrally upwardly from the disc and fitted through the cover 8, at the inside a cap 40. The spring 21 (figure 3) is interposed between the cover 8 and the disc 35 to keep the disc 35 and the obturator 3 engaged and also to increase the contact pressure between the lateral surface 20 of the obturator 3 and the inner surface 5 of the side wall 4 of the box 2. The spring 21 comprises a central annular connection portion 44 fitted to the cover 8 and around the shaft 39 by means of a variety of screws 45 and a variety of blade or blade type arms 46 projecting radially from the portion 44 and elastically cooperating with a peripheral flange or flange 48 of the disc 35, such flange or flange having a formed upper surface 49. More specifically, the surface 49 is corrugated to flex the arms 46 of the spring 21 in a variable manner as the shutter 3 rotates. Such bending is conveniently maximum in the working positions of the valve, to increase the elastic reaction of the spring 21 and hence the contact pressure between the surface 20 of the plug 3 and the surface 5 of the box 2 and is lower in the positions intermediates to assist in the rotation of the obturator 3. The rotation of the obturator 3 is controlled by a pneumatic actuator 50 of 3 positions (Figure 1) which acts on the control shaft 39 via a crank 51. More specifically, the actuator 50 comprises a cylinder 52 hinged to a fixed structure (not shown) of the machine and a rod 53 movable axially with respect to the cylinder 52 and having a fork-like free end 54 hinged to one end of the crank 51. The opposite end of the crank 51 is prismatically connected to the shaft or shaft 39. The operation of valve 1 will now be described with respect to a first working position indicated by the letter a in figure 2 and where the openings 22, 23 of the shutter 3 are positioned facing the respective gates 10, 12 of the box 2; the gates 10, 12 are therefore connected to each other by the passage or passage 24 of the shutter 3 and the product circuit is therefore connected to the sterile air supply circuit. This position is used in the course of the machine's operating cycle to effect the so-called pre-sterilization of the product circuit. When the shutter 3 is rotated 90 degrees counterclockwise in Figure 2, the valve 1 is adjusted to a second working position indicated by the letter b and where the passage or passage 24 connects the gates 11 and 12 to connect the product circuit to the wash solution supply circuit. This position is used to wash the product circuit at the end of the work cycle. As can be seen, any possibility of the fluids being mixed is prevented by the holes or recesses 25, 26, 27, 28 interposed between the gates 10, 11, 12, that is, to get from one gate to the other, any leakage due to the imperfect sealing of the surface 20 of the obturator and the surface 5 of the casing 2 is first intercepted by one of the recesses and drained through the drainage opening 7. Between the two previous working positions, the obturator 3 can also assume an intermediate drainage position where, still with reference to Figure 2, the plug is rotated 45 degrees counterclockwise with respect to the first working position or 45 degrees in the hand direction of the hands. clockwise with respect to the second working position, in such a way that the openings 22, 23, of the shutter 3, correspond to the recesses or recesses 17, 18 of the box 2 and any liquid inside the passage 24 flows from the passage 24 through the recesses or recesses 17, 18 to the drainage opening 7 of the box 2. Furthermore, the recesses or recesses 26, 25, 27 correspond respectively to and thus connect the gates 10, 11, 12 to the drainage opening 7 to drain the circuit branches connected to the gates. The actuator 50 is controlled by a control unit (not shown) of the packaging machine by means of well-known solenoid valves (not shown), such a control unit coordinates the operation of the valve 1 with the other functions of the machine . The advantages of the valve 1 according to the present invention will be clear from the above description. In particular, compared to the known solutions having manually operated moving accessories, the valve 1 provides an automatic selective connection of the gates 10, 11, 12; consequently the switching is direct and extremely rapid and the valve 1 also provides a draining position by which the operating fluids, in particular the washing solution, are drained.

Compared to known valve assemblies or assemblies that perform the same functions, valve 1 is direct, non-expensive and involves very few air charge losses or wash solution. Clearly, changes can be made to the valve 1 as described herein without departing from the scope of the appended claims. In particular, the gates 10, 11, 12 can be arranged differently, for example, separated by 120 degrees; the shutter 3 may comprise only 3 gaps separated by 120 degrees and each interposed between a pair of gates and the gaps 17, 18 of the box 2 and the gaps 25, 26, 27, 28 of the shutter 3 may have a different profile. It is noted that, in relation to this date, the best method known by the applicant to carry out the aforementioned invention is the conventional one for the manufacture of the objects to which it relates.

Claims (11)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A three-way anti-mixing valve for a pourable food product packaging machine, the valve is characterized in that it comprises a box having a lateral wall that defines a cavity having an axis of symmetry and communicating with a lower drainage opening and a rotating plug rotating about the shaft and accommodated in the cavity with a respective lateral surface cooperating in a fluid-tight manner with the side wall of the shaft. box; the box has a first gate and a second gate; both formed in the side wall and angularly spaced by a first angle and a third gate formed in the side wall at an intermediate position with respect to the first and second gate and spaced angularly with respect to each other by a second angle equal to half of the first angle; the rotating shutter has a first opening and a second opening, both formed on the side surface and spaced angularly by an angle equal to the second angle and an internal passage connecting the first and second apertures; the side wall of the box has two internal recesses or recesses formed respectively between the first gate and the third gate and between the second gate and third gate; the rotating shutter comprises at least three recesses or recesses of which a first recess or recess is formed between the first and second openings, a second recess or recess is formed on the opposite side of the second opening with respect to the first recess or recess and spaced angularly with respect to the first recess by an angle equal to the second angle and a third recess is located on the opposite side of the first opening with respect to the first recess and recess and spaced with respect to the first recess by an angle equal to second angle; the recesses or recesses of the box and the recesses of the rotating shutter communicate with the drainage opening of the bottom of the box; the valve comprises drive means for moving the rotary shutter between a first working position in which the first and second openings of the rotary shutter respectively communicate with the first gate and the third gate of the box, an intermediate position in which the first opening and the second opening of the rotary plug communicate with the respective recesses or recesses of the box and the first, second and third doors of the box communicate with respective recesses or recesses of the rotary shutter and a second working position on the which the first opening and the second opening of the rotary shutter respectively communicate with the third gate and the second gate of the box. The valve according to claim 1, characterized in that the side wall of the box has a conical internal surface and in that the lateral surface of the rotary shutter is of a corresponding conical shape; the valve comprises elastic means for axially loading the rotary plug to increase the contact pressure between the lateral surface of the rotary plug and the inner surface of the side wall of the box. 3. The valve in accordance with the claim 1 or 2, characterized in that the recesses or recesses extend along generation lines of the lateral surface of the rotary shutter and of the internal surface of the side wall of the box. 4. The valve in accordance with the claim 2 or 3, characterized in that the recesses or recesses each have a substantially cylindrical concave bottom surface with generation lines parallel to the axis. A valve according to any of claims 2 to 4, characterized in that it comprises a drive disk angularly connected to the rotary shutter and having a control shaft fitted through an upper cover of the box and activated by the means of drive. 6. The valve in accordance with the claim 5, characterized in that the elastic means comprise at least one spring interposed between the cover and the drive disk. 7. The valve in accordance with the claim 6, characterized in that the drive disk comprises an annular flange or flange; the spring comprises at least one flexible arm equipped to the cover and which cooperates with the annular flange or flange to generate variable axial loads on the rotary shutter together with variations in the angular position of the rotary shutter. 8. The valve in accordance with the claim 7, characterized in that the flange or annular flange of the drive disk is formed in such a manner as to generate a maximum axial load on the rotary shutter in the working positions. The valve according to any of the preceding claims, characterized in that the first angle is an angle of 180 degrees and because the second angle is an angle of 90 degrees, the rotary shutter has four of the equally angularly spaced gaps. The valve according to any of the preceding claims, characterized in that the rotary shutter is made of polymeric material with a good sealing capacity and a low coefficient of friction. The valve according to any of claims 5 to 10, characterized in that the driving means comprise a pneumatic cylinder with a rod and a crank that joins the rod of the cylinder to the axis or control shaft of the driving disk.