[0001] The invention relates to vertical-axis carousel machines for filling phials, bottles
or other containers with liquid products. The carousel of such a machine is provided
on its periphery with equally spaced heads, connected to the reservoir of liquid product
to be packaged, with the interposition of a valve means which is securely closed or
opened, usually by mechanical actuators which interact with a cam, and which has a
downward-facing outlet with which the mouth of the bottle to be filled is made to
interact coaxially and in a sealed way when so commanded. A tube which engages in
the bottle to a predetermined depth projects and extends coaxially downwards from
the lower outlet of the head, the lower end of the said tube being used to determine
the level of filling of the liquid in the bottle. The tube allows the gas to escape
from the bottle while the latter is progressively filled with the liquid, and before
filling the same tube is used to pass pressurized gas, usually carbon dioxide, into
the bottle, for cleaning the interior of the said bottle and for other purposes. The
invention relates to filling heads with tubes which are fixed and interchangeable
if necessary, of the counter-pressure type, with automatic pre-closing when the level
determined by the insertion of the tube into the bottle neck is reached, and in which
the said command for the secure closing or opening of the said liquid shut-off valve
also causes the closing or opening of the circuit supplying gas to the tube.
[0002] In the prior art the said valve means can be actuated not only mechanically by levers
and cams, as stated above, but also by means of a fluid-pressure cylinder and piston
unit. The said valve means is associated with a push rod which projects from the upper
part of the head or of the liquid reservoir contained in the head, passing through
lateral sealing means, the upper end of the said push rod interacting with the stem
of an actuator having a reciprocating rectilinear motion, usually consisting of a
fluid-pressure cylinder and piston unit, whose body is fixed to the upper and outer
part of the carousel or of the reservoir, in such a way that it can be easily replaced
when necessary, and which is supplied and actuated by means of suitable boxes and
a rotary distributor located on the shaft of the said carousel. Examples of solutions
of this type are described in European patent application EP 1266862 and in the prior
US patent 4,995,431. These known solutions have the following limitations and drawbacks.
The upper projecting portion of the push rod for actuating the filling head undergoes
reciprocating movements which can lead to the ingress of atmospheric contaminants
into the said head which is isolated from the outside essentially by means of lateral
sealing gaskets. When it is necessary to carry out maintenance, to replace the sealing
gaskets of the pneumatic actuators and the gasket of the push rod for controlling
the gas circuit and for securely closing or opening the main valve of the filling
head, lengthy and complex operations are required. The invention proposes to overcome
these and other drawbacks of the prior art with the following idea for a solution.
The push rod is connected structurally to form a single piece with the stem of the
pneumatic actuator, and the body of the actuator is fixed, for example by screwing
or by some other method so as to be removable, to the upper end of the body of the
head, in such a way that it can be easily removed and fitted to facilitate any necessary
maintenance. The area of connection between the pneumatic actuator and the body of
the filling head is isolated from the outside by highly reliable sealing means which
comprise, in addition to static seals and lateral seals, a bellows which surrounds
the extended part of the stem of the actuator and which has one of its ends connected
with a seal to the body of the said actuator and has its other end connected with
a seal to the lower end of the said stem, for example in the area in which this end
is connected to the push rod which actuates the filling head.
[0003] Further characteristics of the invention and the advantages derived therefrom will
be made clear by the following description which refers to the figures of the attached
drawings, in which:
- Fig. 1 shows a filling head with the improvements in question, in longitudinal section
and in the closed state; and
- Fig. 2 shows an enlargement of the upper portion of the filling head of Figure 1.
Figure 1 shows how the filling head comprises the body 1 of a valve means, fixed for
example laterally or in another way to the periphery of a carousel 2 which rotates
about a vertical axis, a chamber 3 being provided in the said body 1 with a outlet
103 opening downwards and with a lateral aperture 203 connected to a pipe 4 communicating
with the reservoir of liquid to be packaged (not shown), this reservoir being coaxial
with the carousel. The connection of the said outlet 103 to the chamber 3 is shut
off by a plug 5 with corresponding sealing means, which is axially hollow and to which
is fixed, in such a way as to allow for replacement, the tube 6 for supplying the
gas and for determining the filling level of the bottle B, which is elevated, when
so commanded, by known means M so that its mouth meets and forms a seal with a centring
cone 7 provided in a known way under the outlet 103. The chamber 3 of the valve means
is open at its top and communicates with the inner part of the vertical barrel 8 which
forms the composite body of the filling head and whose upper end, provided with lateral
apertures 9 and sealing means 108, abuts the toroidal manifold 10 which is fitted
coaxially on the carousel and which is connected to means for supplying the pressurized
gas, shown schematically by the arrow 11. The plug 5 forms the enlarged lower part
of an axially hollow shaft 105 which engages coaxially in the barrel 8 and which is
guided, with the possibility of axial movement, by a lower bush 12 fixed to the body
1 and by an upper sleeve 13 fixed to an intermediate composite portion of the barrel
8. Below the sleeve 12, the shaft 105 of the plug is provided with a collar 205 which
is at a correct distance from the said sleeve 12 when the said plug is closed as shown
in Figure 1, and which bears against the said sleeve when the plug is open, thus limiting
the upward travel of the said plug. The base of the sleeve 205 is provided with vertical
holes 14 for the passage of the liquid to be distributed, which rises in the barrel
8 until it reaches, for example, the level indicated by 15, in opposition to the pressure
of the gas which enters from above through holes 16 which penetrate the upper sleeve
13. The collar 205 is fixed to a vertical pin 17 which slides in one of the holes
14 so as to prevent any possibility of rotation of the plug unit 5. The cavity of
the shaft 105 of the plug opens at its top in a portion of larger diameter which in
combination with the lower portion forms a conical step 18 interacting with the lower
end, provided with a sealing gasket 119, of a push rod 19 which passes with a clearance
through the said upper portion of the shaft 105 for connection to a reciprocating
raising and lowering actuator which is described more fully below. A spring 20 having
suitable characteristics (see below) is fitted on the upper portion of the shaft 105,
bears on the sleeve 13 with its lower end, and acts with its upper end on a ring 21
which is fixed, in such a way that its height can be adjusted, to the said shaft 105,
which is conveniently pushed upwards by this spring. A pipe 22, which can be connected
to the outside through a normally closed shut-off valve 23, opens laterally into the
outlet 103 which is closed at the top by the plug 105.
[0004] With respect to the parts described up to this point, the filling head is constructed
according to the prior art, except as regards certain differences in construction,
and operates in the following way. At the start of each cycle, the head is in the
state shown in Figure 1. On command, the bottle B is raised so that its mouth is made
to bear in a sealed way against the collar 7. In the next step, the push rod 19 is
raised to allow the gas from the source 11 to pass through the hollow shaft 105 and
to enter the bottle B through this shaft and the tube 6. In this step, the plug 5
remains closed, because the pressure of the gas on the level 15 of the column of product
present in the barrel 8 and the pressure of the liquid on the top of the plug 5 are
grater than the upward thrust exerted by the spring 20. When the pressure of the gas
in the bottle B becomes equal to the pressure inside the barrel 8, the spring 20 acts
to raise the plug 5, causing the product to flow from the pipe 4 to the chamber 3
through the outlet 103 and progressively fill the bottle B. When the level of the
liquid in the bottle reaches the tube 6, the pressure of the gas on the lower face
of the plug 5 is interrupted, and therefore the upper hydrostatic pressure becomes
stronger and automatically closes the plug 5 against the action of the spring 20,
preventing any further outflow of product through the outlet 103 and ensuring an identical
and constant filling level of the bottles. In the next step, before the full bottle
B is lowered, the push rod 19 is lowered so as to close the connection of the gas
through the tube 6, causing the secure closing of the plug 5 and the actuation of
the valve 23 so as to depressurize the outlet 103 and the upper inner part of the
full bottle, to bring the whole to the level of the external atmospheric pressure,
so that the level of the liquid in the bottle is not changed even to the slightest
degree when the bottle is subsequently lowered.
[0005] According to the invention (see also Figure 2), the body 26 of a fluid-pressure cylinder
and piston unit A is fixed removably, for example by screwing as indicated by 24 and
with the interposition of sealing means 25, to the upper end of the barrel 8, the
body 26 having at its lower end an integral base 126 provided at its centre with a
hole having an annular gasket 27 through which passes, with a lateral seal, the stem
28 of the unit A which terminates below in a tapered threaded part 128 screwed into
a cup 29 which is fixed to the push rod 19 and which can be shaped externally with
parallel flat parts for manipulation with an open-ended spanner, for the purpose of
screwing and unscrewing the parts in question, the upper end of the said stem 28 being
provided for this purpose with, for example, a diametric slot 30 for use with a screwdriver,
or being structured in any other suitable way, for example with an axial blind hexagonal
socket. The portion of the stem 28 projecting downwards from the body 26 is surrounded
by a bellows 31 of any flexible, fluid-tight and suitably pressure-resistant material,
whose lower edge 131 is clamped in a sealed way between the lower end of the said
stem 28 and the cup 29 and whose upper edge 231 is fixed to an annular recess provided
laterally on the base 126 of the body of the unit A, this edge being retained in this
recess by bearing against the inner lateral surface of the barrel 8. Clearly, any
communication between the inner chamber of the barrel 8 and the outside is prevented
in the first place by the bellows 31 and also, in a secondary way, by the sealing
ring 27.
[0006] The top of the stem 28 terminates in an enlarged part 228 acting as a piston, which
slides with a lateral seal on the inner surface of the body 26 with its gasket 32
and with a head 328 provided with an annular recess engaged by a lip seal 33 which
also forms a seal with the inner lateral surface of the body 26 of the unit A which
is closed at its top in a sealed way by means of the gasket 34 and the cap 35 which
is fixed removably, by screwing for example. The cap 35 is provided with a threaded
hole to which is fixed the connector 36 for connecting the pressure chamber Z to the
circuit for the cyclic supply of pressurized air or for connecting the said chamber
Z to the atmosphere, preferably through calibrated discharge means (not shown) in
such a way that the raising of the piston 28 is slowed conveniently by the action
of an opposing spring 37 which operates in the lower chamber of the unit A, and which
bears upwardly against the piston 128 and downwardly against the base 126. The said
lower chamber of the unit A communicates freely with the atmosphere through one or
more lateral holes 38, to prevent excess pressure or cavitation phenomena. The outer
lateral surfaces of the body 26 and of the cap 35 are preferably shaped so that they
can be easily manipulated with spanners for screwing and unscrewing. Clearly, it is
possible, by unscrewing the body 26 from the top of the barrel 8, to remove the whole
cylinder and piston unit A from the filling head, while the push rod 19 remains attached
to this unit, so that the gasket 119 of this component can also be replaced periodically
without the need to carry out the specific dismantling and re-assembly operations
which are required in the prior art. The operations for replacing the various gaskets
of the unit A and of the bellows 31 are simple and rapid. Finally, Figure 2 shows
how, when the push rod 19 is in the operating position inside the hollow shaft 105,
it is guided and centred correctly in the said shaft by a sleeve 39 of any suitable
material which has a low coefficient of friction and is usable with food products,
provided longitudinally and externally with one or more grooves or flats 40 for the
passage of the gas.
1. Fluid-pressure device for actuating counter-pressure heads with fixed interchangeable
tubes (6) of carousel filling machines for packaging liquid products in phials, bottles
or the like, the heads being provided with automatic pre-closing when the level determined
by the insertion of the said tube into the neck of the bottle is reached, the actuator
for securely closing or opening the liquid shut-off valve (5) comprising a push rod
(19) which also closes or opens the gas circuit leading to the said tube (6), characterized in that the said push rod (19) is connected structurally so as to form a single piece with
the stem (28) of a fluid-pressure actuator (A), preferably of the pneumatic type,
and the body (26) of this actuator is fixed, for example by screwing or by some other
method so as to be removable, and with sealing means (25), to the upper end of the
barrel or body (8) of the filling head, in such a way that it can be easily removed
and fitted to facilitate any necessary maintenance, the area of connection between
the pneumatic actuator and the said barrel (8) being isolated from the outside by
highly reliable sealing means which comprise, in addition to static and lateral seals,
a bellows (31) of any fluid-tight, flexible and pressure-resistant material which
surrounds the extended part of the stem (28) of the actuator (A) and which has one
of its ends connected with a seal to the lower part or base (126) of the body of the
said actuator and has its other end connected to the end of the said stem, for example
in the area in which this end is connected to the push rod (19) which actuates the
filling head, the whole being arranged in such a way that, when the actuator (A) is
removed from the top of the barrel (8), this actuator remains attached to the push
rod (19), whose sealing gasket (119) can also be periodically replaced.
2. Device according to Claim 1), in which the body (26) of the pneumatic actuator (A)
has in its lower part a base (126) provided at its centre with a hole with an annular
gasket (27) through which passes, with a lateral seal, the stem (28) of the said actuator,
which terminates below in a tapered threaded part (128) screwed into a cup (29) which
is fixed to the upper end of the push rod (19) and which can be shaped externally
with parallel flat parts for manipulation with a spanner, for the screwing and unscrewing
of the parts in question, the upper end of the said stem (28) being provided for this
purpose, for example, with a diametric slot (30) for use with a screwdriver, or being
structured in any other suitable way, for example with an axial blind hexagonal socket.
3. Device according to Claim 2), in which the portion of the stem (28) projecting downwards
from the body (26) of the pneumatic actuator (A) is surrounded by a bellows (31) whose
lower edge (131) is clamped in a sealed way between the lower end of the said stem
(28) and the said cup (29) and whose upper edge (231) is fixed to an annular recess
provided laterally on the base (126) of the said body (26) of the actuator (A), this
edge being retained in this recess by bearing against the inner lateral surface of
the barrel (8).
4. Device according to Claim 2), in which the stem (28) of the pneumatic actuator (A)
terminates upwardly in an enlarged part (228) acting as a piston, which slides with
a lateral seal on the inner surface of the body (26) of the said actuator, by means
of at least one of its gaskets (32), this piston having an upper head (328) provided
with an annular recess engaged by at least one lip seal (33) which also forms a seal
with the inner lateral surface of the said body (26) of the actuator (A), this body
being closed at its top in a sealed way by means of a gasket (34) and a cap (35) fixed
removably, by screwing for example, and provided with a threaded hole to which is
fixed the connector (36) for connecting the pressure chamber (Z) to the circuit for
the cyclic supply of pressurized air or for connecting the said chamber (Z) to the
atmosphere, preferably through calibrated discharge means in such a way that the raising
of the piston (28) is slowed conveniently by the action of an opposing spring (37)
which operates in the lower chamber of the actuator (A), and which bears upwardly
against the piston (228) and downwardly against the base (126), this lower chamber
of the actuator communicating freely with the atmosphere through one or more lateral
holes (38).
5. Device according to the preceding claims, in which the outer lateral surfaces of the
body (26) and of the cap (35) of the pneumatic actuator (A) are shaped so as to be
easily manipulated with spanners for screwing and unscrewing.
