Fluid control method and device

A liquid packaging machine includes a filler containing a non-return valve spring-biased closed. The valve includes a closure member to a stem of which is fixed a centering spider, the spokes of which contain iron members. Distributed around the valve housing are horseshoe, permanent magnets. During production of filled cartons, the magnet device is positioned so as not to interfere with the movement of the closure member. However, when air is to be bled from the filler and/or the filler is to be steam-sterilized, the magnet device is positioned to attract the iron members to open the valve against the spring bias.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a fluid control device, in particular a 
non-return valve arrangement in a packaging machine. 
2. Description of the Prior Art 
In liquid packaging machines it is conventional to have dosing fillers 
containing non-return valves which control the liquid flow through the 
fillers to the packaging containers. These valves are spring-biassed into 
their closed positions and are forced open by the liquid as it is pumped 
stepwise towards the containers. For example, EP0090664A discloses a 
liquid packaging machine in which the dosing filler comprises upper and 
lower bellows tubes co-axial with each other and with a first, 
spring-biassed, non-return valve by way of which the upper bellows tube 
communicates with the lower bellows tube. The lower bellows tube 
communicates with a filling nozzle arranged co-axially beneath it and 
containing a second spring-biassed, non-return valve. 
The liquid is pumped through the filler by vertical reciprocation of the 
first non-return valve. 
To sterilize such a filler internally, it is conventional to pump a 
sterilizing liquid therethrough in the same manner as the filling liquid 
is pumped therethrough. However, sterilizing liquid residues may remain in 
the filler and need flushing out before filling can commence. The flushing 
medium can be steam, in which case the filler becomes full of gaseous 
matter. To remove the gaseous matter, the product can be pumped through 
the filler, in which case the product may not be re-usable and the process 
of removal takes some time. 
It may be preferable to employ steam for sterilization, rather than to 
employ a sterilizing liquid, because any steam residues are simply pure 
water, but again the filler becomes full of gaseous matter. 
Magnetic operation of fluid control valves is well known, as can be seen 
from, for example, U.S. Pat. Nos. 2,589,188; 3,652,054: 4,349,042; 
3,774,878: DE2234972A; DE3515848 and FR1106163. 
The movable closure member of the valve comprises soft or hard magnetic 
material, or is connected to another member which is of soft or hard 
magnetic material. Disposed externally of the valve housing is either a 
permanent magnet movable between an active position in which it controls 
the closure member and an inactive position, or an electromagnet 
energisible to control the closure member. FR1106163 and DE 2234972A both 
discloses non-return valves biassed closed by springs and with 
electromagnets energisible to open the valve closure members. 
SUMMARY OF THE INVENTION 
According to one aspect of the present invention, there is provided a 
method of utilizing ducting containing a non-return valve including 
biassing means biassing a valve closure member of said valve into a closed 
position, comprising forcing said valve closure member out of said closed 
position to an open position against the action of said biassing means by 
pressing production fluid in said ducting against said valve closure 
member, whereby said production fluid flows through the open valve; 
operating magnetic means disposed externally of said ducting to maintain 
said closure member in an open position against the action of said 
biassing means; and passing a cleaning fluid through said ducting and the 
open valve, while said magnetic means maintains said closure member in the 
latter position. 
According to a second aspect of the present invention, there is provided a 
method of utilizing ducting containing a non-return valve including 
biassing means biassing a valve closure member of said valve into a closed 
position, comprising forcing said valve closure member out of said closed 
position to an open position against the action of said biassing means by 
pressing production fluid in said ducting against said valve closure 
member, whereby said production fluid flows through the open valve; 
substantially ceasing said pressing, whereby said valve closure member 
returns to said closed position under the action of said biassing means; 
oparating magnetic means disposed externally of said ducting to displace 
said closure member out of said closed position into an open position 
against the action of said biassing means; and passing a cleaning fluid 
through said ducting and the open valve while said magnetic means 
maintains said closure member in the latter position. 
According to a third aspect of the present invention, there is provided a 
method of utilizing ducting disposed at an angle to the horizontal and 
containing a non-return valve including biassing means biassing a valve 
closure member of said valve upwardly into a closed position, comprising 
forcing said closure member downwardly out of said closed position to an 
open position against the action of said biassing means by pressing liquid 
in said ducting against said closure member, whereby said liquid flows 
downwards through the open valve; substantially ceasing said pressing, 
whereby said closure member returns to said closed position under the 
action of said biassing means; and operating magnetic means disposed 
externally of said ducting to displace said closure member downwards out 
of said closed position into an open position against the action of said 
biassing means, whereby gaseous fluid downstream of said valve may rise 
through the open valve. 
According to a fourth aspect of the present invention, there is provided 
apparatus comprising ducting; a non-return valve contained in said 
ducting, said valve comprising a valve closure member and biassing means 
biassing said closure member into a closed position; pumping means 
communicating with said ducting and serving to press production fluid 
against said closure member to force said closure member out of said 
closed position into an open position against the action of said biassing 
means; and magnetic means disposed externally of said ducting and operable 
to maintain said closure member in an open position against the action of 
said biassing means. 
Owing to the invention, it is possible, with ducting containing a 
non-return valve which is opened by the pressure of production fluid in 
the ducting, to hold the valve open, in the absence of that opening 
pressure, to allow passage of a cleaning fluid, or of unwanted gaseous 
fluid, through the valve. 
According to a fifth aspect of the present invention, there is provided in 
a packaging machine, a filler for filling containers with a production 
fluid, said filler including ducting, a valve contained in said ducting, 
said valve including a valve closure member, and magnetic means disposed 
externally of said ducting and operable to displace said valve closure 
member relative to said ducting. 
This is a particularly advantageous application of a 
magnetically-controlled valve.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The valve shown in the FIGS. 1 and 2 is at a filling stage (see FIG. 6) of 
an aseptic packaging machine (see FIG. 5), in which cartons are filled 
aseptically with a liquid, such as milk. The valve includes a tubular 
casing 1 formed of non-magnetic material and sealingly connected coaxially 
to pipes 2 and 3 of the filler. The lower and outlet end of the casing 1 
is formed with a coaxial annular shoulder 4 acting as a valve seat, 
co-operating with a valve closure member 5 fixed to a valve stem 6. The 
stem 6 is fixed at its upper end to a hub 7 of a centering spider 8 formed 
of non-magnetic material and movable with the closure member 5. Beneath 
the spider 8 is an abutment ring 9 fixed co-axially to the interior of the 
casing 1. Spaced below the abutment ring 9 and also fixed co-axially to 
the interior of the casing 1 is a fixed spider 10 having a hub 11 closely 
encircling the stem 6. A helical compression spring 12 acting between the 
hubs 7 and 11 urges the movable valve means 5 to 8 upwardly. Distributed 
at regular angular intervals around the external periphery of the casing 1 
are a plurality of horseshoe, permanent magnets 13 which are mounted in an 
external ring 14 coaxial with the casing 1 and inwardly of which are upper 
and lower pole rings 15 and 16. Inserted into the spokes of the spider 8 
are iron nuts 17 which can be magnetically attracted to the pole rings 15 
and 16. 
FIG. 1 shows the condition of the parts 13 to 16 during production of 
filled cartons by the machine. In this condition, the iron nuts 17 remain 
sufficiently out of the magnetic field between the rings 15 and 16, even 
when the spider 8 is abutting against the ring 9, that the valve means 5 
to 8 can operate without any interference from the magnetic field. 
In certain circumstances, when the machine is not producing and air is to 
be bled from the filler and/or the filler is to be stream-sterilized, it 
is desired that the valve means 5 to 8 should be held at least partly open 
against the action of the spring 12. Such a condition, in which the valve 
is being held fully open, is shown in FIG. 2, in which the nuts 17 are 
exposed to the concentrated magnetic flux between the pole rings 15 and 
16. Thereby, the movable valve means 5 to 8 is held fully open. 
To bring the valve from the condition shown in FIG. 1 to that shown in FIG. 
2, the assembly 13 to 16 is raised until the iron nuts 17 are magnetically 
attracted and displaced towards the gap between the rings 15 and 16, and 
then the assembly 13 to 16 is lowered to open the valve to the required 
degree. To terminate the magnetic attraction of the iron nuts 17 to the 
concentrated magnetic flux, the assembly 13 to 16 and thus the magnetic 
field is then lowered, the abutment ring 9 prevents the iron nuts 17 from 
following the magnetic field, and the spring 12 displaces the spider 8 
upwards. 
The version shown in FIGS. 3 and 4 differs from the version shown in FIGS. 
1 and 2 chiefly in that the pole rings 15 and 16 are omitted and the iron 
nuts 17 are replaced by short vertical iron rods 17' totally cast into the 
spider 8, which is of plastics, and in that the assembly 13 and 14 during 
the production condition is in an uppermost position indicated in dot-dash 
lines at 13' in FIG. 3. FIG. 3 shows in full lines the position of the 
assembly 13 and 14 with the rods 17' spanning the limbs of the horseshoe 
magnets 13 and with the valve closure member 5 about to be lowered, and 
thus opened, by lowering of the assembly. 
Referring to FIGS. 5 and 6, the packaging machine is almost totally 
enclosed in a housing 18 with openable air-tight transparent windows 19 
through which can be seen a bottom closure forming-and-sealing device 20, 
a top closure breaker 21, a sterile air inlet 22, the filler 23, a top 
closure heater 24, a top closure sealer 25, and a discharge 26. The filler 
23 includes a reservoir 27 for liquid product and ducts 28 leading to 
respective metering pumps 29 whence respective ducts 30 lead to respective 
filling nozzles 31. The ducts 28 contain respective valve devices not 
seen, but each as described with reference to FIGS. 1 and 2, or FIGS. 3 
and 4. The rings 14 of the respective valve devices are interconnected by 
a yoke 32 which can be raised and lowered, to raise and lower the rings 
14, by a pneumatic piston-and-cylinder device (not shown) through a 
linkage 33. 
A particular advantage of the valve device described with reference to the 
drawings is that there is no mechanical control connection from externally 
to internally of the valve housing, so reducing sealing problems and 
cleaning problems, and thus reducing the risks of contamination of the 
product. 
Alternatively to the use of permanent magnets, a DC electromagnetic coil 
could be used.