[0001] The present invention relates to a valve unit for a machine for filling containers,
particularly a bottle filling machine.
[0002] In certain cases the process of filling containers encounters difficulties relating
to the nature of fluids such as milk or tea, for example. This type of fluid, under
filling conditions, tends to form large amounts of foam which may then spill over
the sides of the container, with the immediate loss of some of the drink. With sugary
or flavoured drinks there is also the problem that the outside of the container and
the work surface are made dirty by the residues of the fluid, which means that the
filled containers require external washing and the work surface has to be frequently
cleaned.
[0003] In addition to these problems, foam formation impedes correct operation of the valve
unit and tends to leave it contaminated with drink residues.
[0004] The problems delineated above are aggravated by the fact that foam formation is particularly
evident in industrial-scale filling operations, because the high speed at which the
liquid is filled into the container increases its turbulence and so makes the problem
all the greater.
[0005] The problem addressed by the present invention is therefore that of providing a liquid
dispensing system for a filling machine that will overcome the problems inherent in
the filling operations carried out by the devices of the prior art.
[0006] This problem is solved with a valve unit as delineated in the appended claims.
[0007] Other features and advantages of the valve unit for a filling machine that forms
the subject-matter of this invention will become clearer in the course of the description
given below by way of non-limiting indication, of one preferred embodiment, with reference
to the following figures, in which:
Figure 1 is a sectional side view of the valve unit of the invention, in the closed
condition;
Figure 2 is the same view as Figure 1, but with the valve open; and
Figure 3 is a sectional side view of a detail of Figure 2 during filling.
[0008] Referring to the figures, the valve unit of the invention, indicated as a whole by
the number 1, comprises a hollow body 2 housing a sliding plug 3.
[0009] The hollow body 2 comprises an inlet aperture 4 and an outlet aperture 5 for the
fluid 6 with which the container 7 is to be filled. The said inlet aperture 4 is situated
on the lateral surface of the hollow body 2, while the outlet aperture 5 is formed
in its lower surface, in alignment with the plug 3. As a result, a passage 8 for the
filling fluid 6 will be defined inside the said hollow body 2, which cavity, being
coaxially occupied by the plug 3, will be essentially annular in shape.
[0010] The hollow body 2 of the valve unit 1 is essentially cylindrical in shape and its
diameter, in cross section, is greater than the diameter of the outlet aperture 5.
The connecting portion 9 between the larger-diameter cylindrical body and the outlet
aperture 5 is ogival in section, truncated below at the said outlet aperture 5 for
the filling fluid 6.
[0011] A plurality of fins 43 for stabilizing the flow of filling fluid 6 is arranged on
the inside surface of the hollow body 2.
[0012] The valve unit 1 also includes guide means 10 for the plug 3. These guide means 10
comprise a perforated disc 11 fixed to the top edge 12 of the hollow body 2. Extending
down from the perforated disc 11 around the central hole is a sleeve 13 through which
the plug 3 will be able to slide. The sleeve 13 ends at the bottom, approximately
half-way through the longitudinal length of the hollow body 2, in an outward flange
14.
[0013] Inside the sleeve 13 is a tubular part 15 whose axial length is slightly greater
than that of the sleeve 13. The tubular part 15 ends at the bottom in an outwardly
projecting flange 16. The upper surface of the flange 16 includes an annular relief
17.
[0014] A ring 18 is fixed removably, for example by means of a screw thread, to the outside
of the tubular part 15, near its upper end, for axial retention of this cylindrical
part.
[0015] An envelope 19 mounted on top of the perforated disc 11 encloses the upper portion
of the plug 3 and its actuating means. The envelope 19 is closed at the top by a cap
19a with a central hole housing a cylinder 24 containing its own coaxial bore. The
cylinder 24 is attached to the cap 19a by known fixing means 25.
[0016] The plug 3 comprises a tubular body 20, fixed to the bottom end of which is a closing
member 21, which is basically bulb-shaped in the example: this serves to shut off
the outlet aperture 5 of the valve unit when the latter is in the non-operating condition.
The closing member 21 is preferably interchangeable to suit filling requirements.
[0017] The upper portion of the closing member 21 extends some way into the hole of the
tubular body 20 and ends in an inwardly projecting abutment ring 32.
[0018] Both the tubular body 20 and the closing member 21 are hollow and open at their respective
ends, thus defining a coaxial channel 23 running the entire length of the plug 3,
being open at the top inside the envelope 19 and at the bottom on the outside of the
valve unit 1, at the tip of the plug.
[0019] A sliding cannula 26 is housed in the channel 23, passing axially through the plug
3 and continuing above it through the envelope 19, the central hole in the cylinder
24 and emerging above on the outside of the valve unit.
[0020] At the bottom end of the cannula 26 are flow deflector means. In the example shown,
these deflector means consist of the frustoconical portion 27 which projects outwards
with a flared surface. The top end of the cannula 26 meanwhile is open to let air
out.
[0021] Observing the plug 3 in detail, the outer surface of the tubular body 20 ends at
the top, inside the envelope 19, in a smaller-diameter portion, which is joined to
the lower portion by a shoulder on which rests an annular disc 22. The upper surface
of the annular disc 22 is stepped in cross section.
[0022] Held between the lower edge of the tubular body 20 and the closing member 21 is one
edge of an annular diaphragm 29 isolating the passage 8 for the filling fluid 6. The
upper edge of this diaphragm is gripped between the lower surface of the flange 14
of the sleeve 13 and the annular relief 17 of the flange 16 of the tubular part 15.
The annular diaphragm 29 ensures the asepsis of the outgoing flow of fluid 6, preventing
contamination by the unsterile air that could get in from the channel 23 of the closure
member 3.
[0023] The two end sections of the channel 23 - the upper end section in the upper portion
of the tubular body 20 and the lower end section in the lower portion of the closing
member 21 - have approximately the same diameter as the cannula 26, while the remaining
central tract of the channel 23 has a larger diameter so as to define a tubular chamber
30. A seal 31, such as an 0-ring, positioned in a seating on the surface of the channel
23 near its upper end, prevents leaks at the upper end of the tubular chamber 30.
[0024] The tubular chamber 30 is divided by the abutment ring 32 into an upper half-chamber
and a lower half-chamber. The cannula 26 possesses a piston portion 33 where the diameter
is approximately the same as the diameter of the tubular chamber 30. The said piston
portion 33 is housed in the lower half-chamber of the tubular chamber 30 and, in the
non-operating condition, is immediately underneath the abutment ring 32. A seal 34,
such an O-ring, housed in a seating on the surface of the piston portion 33 of the
cannula 26, prevents leaks at the lower end of the upper half-chamber.
[0025] The said lower half-chamber of the tubular chamber 30 is further subdivided into
two portions with different diameters, connected by a shoulder 35. Another shoulder
defines the connecting point between the end portion of the channel 23, which as described
earlier has a diameter approximately equal to the diameter of the cannula 26, and
the half-chamber above it. Means for returning the cannula 26, in this case a spring
36, press down on this latter shoulder. These return means 36 also act upwards against
the piston portion 33 of the cannula 26. As will be realized from the above account,
the lower half-chamber of the tubular chamber 30, which is that lying between the
abutment ring 32 and the shoulder 35, defines the stroke of the piston portion 33
of the cannula.
[0026] A connector 37 to a tube 38, which is in fluid communication with a source of compressed
air or other pressurizing fluid, feeds into the upper half-chamber of the tubular
chamber 30, immediately underneath the annular disc 22.
[0027] Turning now to the detail of the actuating means of the plug 3, these comprise a
deformable lung element 28 made of an elastic material such as a rubber tube. The
lung element 28 is housed within the envelope 19 and sits around the cannula 26. The
lung element 28 is attached at one end to the lower surface of the cap 19a of the
envelope 19 and at the other end to the upper surface of the annular disc 22.
[0028] The lung element 28 is associated with return means, in this case a spring 39. The
spring 39 is arranged concentrically around the outside of the lung element 28 and
it too presses on the lower surface of the cap 19a of the envelope 19 and on the upper
surface of the annular disc 22.
[0029] Between the inside surface of the lung element 28 and the cannula 26, a gap is created
which constitutes a pressurization chamber 40. The cylinder 24 possesses, on the portion
outside the envelope 19, an aperture 41 for the injection of compressed air, which
can reach the pressurization chamber 40 because of a gap between the cannula 26 and
the hole of the cylinder 24. Suitable seals 42, 42', 42'', such as 0-rings, keep the
pressurization chamber 40 leaktight. The aperture 41 is in flow communication with
a source of compressed air or other pressurizing fluid.
[0030] Remaining with the figures, the operation of the valve unit according to the invention
will now be described.
[0031] In the closed condition, the valve unit 1 is as shown in Figure 1. In this condition
the closing member 21 interacts with the edge of the outlet aperture 5 of the hollow
body 2 to seal it.
[0032] The valve is actuated by injecting compressed air through the aperture 41 into the
pressurization chamber 40. The compressed air causes the lung element 28 to expand,
consequently reducing its axial length. The axial shortening of the lung element 28
lifts the annular disc 22, to which it is attached, and hence also the plug 3, in
opposition to the spring 39. Simultaneously, or immediately before this, compressed
air is also injected through the connector 37 into the tubular chamber 30 so as to
act on the piston portion 33 of the cannula 26, causing it to slide down in opposition
to the spring 36. The cannula 26 is therefore pushed out and protrudes from the closing
member 21 by the amount permitted by the stroke of the piston portion 33 until it
meets the lower shoulder 35 of the tubular chamber 30 (Figure 2). In this way, as
shown in Figure 3, the cannula 26 passes into the neck of the container 7 and, by
means of the deflector means 27 at its lower end, will direct the flow of filling
fluid 6 onto the walls of the container, thereby reducing or eliminating foam formation.
[0033] After the filling fluid 6 has been dispensed, the injection of compressed air is
suspended both through the aperture 41 and through the connector 37. The respective
springs 39, 36 will relax and move the plug 3 back so that it closes the outlet aperture
5 of the hollow body 2 and also return the cannula 26 to the retracted position.
[0034] Compressed air can be injected into the valve unit 1 via solenoid valves (not shown)
controlled by a command and control unit. The amount of fluid dispensed is monitored
by known flow-measuring means.
[0035] The advantages of the valve unit according to the present invention will be immediately
apparent from the above description.
[0036] In the first place, the use of the cannula 26, with its flow deflector means, minimizes
foam formation and therefore facilitates the filling operation even with very problematic
liquids such as tea or milk.
[0037] The diaphragm 29 helps to maintain optimal asepsis during filling by isolating the
internal mechanisms of the plug from the passage 8 for the fluid 6.
[0038] The valve unit is simple in terms of construction and is easy to operate. The type
of means for actuating the plug 3 and the cannula 26 minimizes maintenance requirements.
[0039] It will be obvious that only one particular embodiment of the valve unit of the present
invention has been described, and that a person skilled in the art will be able to
make all necessary modifications thereto for its adaptation to particular applications,
without thereby departing from the scope of protection of the present invention.
1. Valve unit (1), particularly for a machine for filling containers (7), comprising
a hollow body (2) housing a sliding plug (3), the unit being characterized in that the said plug (3) is provided with deflector means (27) for deflecting the flow of
a filling fluid (6) onto the internal walls of the said container (7) .
2. Valve unit according to Claim 1, in which a channel (23) formed inside the said plug
(3) houses a sliding cannula (26), the said cannula (26) being moveable between a
retracted position inside the said plug (3) and an extended position, and in which
the said deflector means (27) of the flow of fluid (6) are operatively connected to
the said cannula (26).
3. Valve unit according to Claim 2, in which the said cannula (26) comprises a frustoconical
end portion (27) projecting outwards with a flared surface which constitutes the said
flow deflector means.
4. Valve unit according to any one of Claims 1 to 3, in which the said cannula (26) comprises
a piston portion (33) that can be moved by the action of a pressurized fluid such
as compressed air, in opposition to return means (36), between first and second positions
inside a chamber (30) into which the said pressurized fluid is injected, the said
first position corresponding to the retracted condition and the said second position
corresponding to the extended condition of the said cannula (26).
5. Valve unit according to any one of Claims 1 to 4, in which the said plug (3) is operatively
connected to actuating means comprising:
- A lung element (28) that can be inflated by a pressurized fluid such as compressed
air injected into a pressurization chamber (40) located inside the said lung element
(28), the said lung element (28) being connected at the lower end to the said plug
(3) and at the upper end to the cap (19a) of the envelope (19) in which the said actuating
means are housed, and
- return means (39) arranged concentrically around the outside of the said lung element
(28) and acting on the said plug (3) and on the said cap (19a) of the said envelope
(19),
βββin such a way that inflating the said lung element (28) causes it to shorten in
the axial direction and consequently lifts the said plug (3) from the non-operating
valve-closed position to the valve-open position.
6. Valve unit according to Claim 4 or 5, in which the said return means (36, 39) are
springs.
7. Valve unit according to any one of Claims 1 to 6, in which a plurality of fins (43)
are arranged around the internal surface of the said hollow body (2) to stabilize
the flow of outgoing fluid (6).
8. Valve unit according to any one of Claims 1 to 7, in which guide means (13, 15) for
the said plug (3) are located on its outside.
9. Valve unit according to any one of Claims 1 to 8, in which the said plug (3) comprises
an interchangeable closing member (21).