U.S. patent application number 14/114675 was filed with the patent office on 2014-05-08 for container closure sterilising unit.
This patent application is currently assigned to SIDEL S.p.A. CON SOCIO UNICO. The applicant listed for this patent is Emilio Gainotti Cavazzini, Andrea Trevisan. Invention is credited to Emilio Gainotti Cavazzini, Andrea Trevisan.
Application Number | 20140124681 14/114675 |
Document ID | / |
Family ID | 44317720 |
Filed Date | 2014-05-08 |
United States Patent
Application |
20140124681 |
Kind Code |
A1 |
Trevisan; Andrea ; et
al. |
May 8, 2014 |
CONTAINER CLOSURE STERILISING UNIT
Abstract
A container closure sterilising unit including at least one
closure treatment station and a device for feeding a plurality of
container closures to the closure treatment station. The feeding
device having a guiding means defining a conveying path that
includes at least one linear tract and along which the treatment
station is positioned. The feeding device includes a conveying
means associated with the guiding means and operable to advance the
plurality of closures toward the treatment state spaced along the
conveying path.
Inventors: |
Trevisan; Andrea; (Parma,
IT) ; Gainotti Cavazzini; Emilio; (Parma,
IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Trevisan; Andrea
Gainotti Cavazzini; Emilio |
Parma
Parma |
|
IT
IT |
|
|
Assignee: |
SIDEL S.p.A. CON SOCIO
UNICO
Parma
IT
|
Family ID: |
44317720 |
Appl. No.: |
14/114675 |
Filed: |
May 2, 2012 |
PCT Filed: |
May 2, 2012 |
PCT NO: |
PCT/EP2012/058052 |
371 Date: |
January 27, 2014 |
Current U.S.
Class: |
250/455.11 |
Current CPC
Class: |
B67B 3/06 20130101; B65B
55/08 20130101; B67B 3/003 20130101 |
Class at
Publication: |
250/455.11 |
International
Class: |
B65B 55/08 20060101
B65B055/08 |
Foreign Application Data
Date |
Code |
Application Number |
May 2, 2011 |
IT |
TO2011A000383 |
Claims
1. A container closure sterilizing unit, comprising: at least one
closure treatment station and a feeding device for feeding a
plurality of container closures to said closure treatment station;
said feeding device comprising guiding means defining a conveying
path including at least one linear tract and along which said at
least one treatment station is positioned; wherein said feeding
device includes a conveying means operatively associated with said
guiding means and operable to advance said plurality of closures
toward said treatment station positioned along said conveying
path.
2. The sterilizing unit of claim 1, wherein said conveying means
includes a helical coil operable to advance said closures along
said conveying path in single file and fed to said at least one
treatment station with uniform speed.
3. The sterilizing unit of claim 2, wherein a longitudinal axis of
said helical coil extends parallel to said tract of conveying
path.
4. The sterilizing unit of claim 2, wherein said helical coil is
born by a shaft substantially coaxial with coil and driven by motor
means.
5. The sterilizing unit of claim 2, wherein said helical coil is
hollow and configured to receive a flow of a thermal carrier
fluid.
6. The sterilizing unit of claim 1, wherein said guiding means
includes a plurality of guides.
7. The sterilizing unit of claim 6, wherein at least for a portion
of said guides are inclined relative to the horizontal
direction.
8. The sterilizing unit of claim 6, wherein said guides includes:
at least one first guide extending, at least along said tract of
conveying path, parallel to said tract and operatively active on a
lateral edge surface of closures; and at least one second guide
cooperating with a top surface of said closures.
9. The sterilizing unit of claim 1, including an outer casing
adapted to house said guiding means and said conveying means.
10. The sterilizing unit of claim 9, wherein said outer casing has
at least a first service window positioned in the location of said
closure treatment station to enable treatment of said closures
travelling along said path, the sterilizing unit including at least
one source of ionizing radiation arranged at a relative service
window.
11. The sterilizing unit of claim 3, including a plurality of
strengthening guide elements extending parallel to said axis of
said helical coil and substantially tangential to the convolutions
of said helical coil.
Description
TECHNICAL FIELD
[0001] The present invention relates to the field of container
processing, with particular reference to the bottling industry.
[0002] In particular, the present invention relates to a unit for
sterilising closures to be applied on relative containers.
BACKGROUND ART
[0003] As it is generally known, the need exists in the food
industry to sterilise containers, both internally and externally,
prior to filling them with food products, such as e.g.
beverages.
[0004] Commonly, for sterilisation use is made of chemical agents,
like hydrogen peroxide or peracetic acid, which are compatible with
virtually any type of material, including paper, cardboard, metals
and plastics.
[0005] With a view to ensuring that filling operations are
performed under aseptic conditions, not only must containers be
sterilised, but also their closures, such as caps or stoppers,
which are used for sealing containers once the filling operation is
finished, need to undergo a similar treatment.
[0006] Typically, sterilisation of closures, be they caps or
stoppers, is obtained by means of ionising radiation or of chemical
agents.
[0007] Ionising radiation consists of particles or electromagnetic
waves that are energetic enough to detach electrons from atoms or
molecules, thus ionising them. Direct ionisation induced by single
particles or single photons produces free radicals, i.e. atoms or
molecules containing unpaired electrons, that tend to be especially
chemically reactive due to their electronic structure. On the other
hand, interaction between a particle or photon and an atom or
molecule also frees one or more electrons, which are, in turn,
capable of generating additional ions.
[0008] In particular, for sterilisation purposes, electron beam
emitters are commonly used in the art. In practice, electron beams
are directed on the object to be sterilised in such a manner that
electrons can act directly on pathogenic agents, such as viruses,
funguses or bacteria, in order to damage the DNA thereof and
deactivate the proteins and enzymes necessary to their
survival.
[0009] Sterilisation by means of ionising sources has the important
advantage of reducing operating costs of filling/bottling plants,
since consumption of chemical agents, water and sterilising
substances is greatly reduced if not eliminated altogether.
[0010] Furthermore, the use of sources of ionising radiation as the
sterilising agent positively affects environmental issues such as
chemical residue disposal.
[0011] With particular reference to the sterilization of caps and
stoppers, apparatus equipped with a magazine for containing caps
and stoppers, connected to a chute for feeding the latter to a
sterilisation zone, where they are submitted to ionising radiation
of the type described above, are generally known within the
bottling industry.
[0012] Apparatus of this type have a major drawback in that they do
not guarantee complete, reliable sterilisation. In fact, shadow
zones tend typically to form where the surfaces of two adjacent
closures arranged in single file on the feed chute contact each
other. In these shadow zones, ionising radiations fail to fully
perform their function. Consequently, pathogenic agents present in
those shadow zones are very likely to not be eliminated, the
overall sterility of the closures, be they caps or stoppers, being
thus greatly compromised.
[0013] WO2009/139013 discloses a sterilising unit associated with a
device for feeding container closures, the device comprising guides
for conveying the closures to a treatment station and a star wheel
with a plurality of projections and recesses suitable for receiving
the closures, operatively associated with the guides, and adapted
to deliver the closures to the treatment station at evenly spaced
time intervals.
[0014] The star wheel can move alternatively between a position for
blocking the queue of closures approaching the sterilising station
and a position enabling the forward movement thereof towards the
sterilising station.
[0015] For this arrangement to operate correctly, it is however
essential that the star wheel rotate to impart to each closure an
initial velocity, the closure subsequently being accelerated due to
the combined effect of gravity and the inclination of the
guides.
[0016] Accordingly, the inclination of the guides needs to be at
least great enough to offset friction. On the other hand,
inclination cannot be as great as to cause the closures to reach a
speed such that they are exposed to the sterilising means for too
short. These design limitations therefore must always be taken into
account.
[0017] Furthermore, the star wheel needs to be actuated in such a
manner that a sufficient initial velocity is imparted to each and
every closure. Besides, for ensuring that adjacent closures are
properly evenly spaced, actuation of the star wheels needs to be
carefully timed and controlled. A solution such as the one known
from WO2009/139013 has therefore the drawback of certain inherent
design constraints, and it is only by precisely controlling how the
star wheel is actuated, both in terms of the frequency with which
it is alternately rotated and stopped, as well as of the speed
imparted by the star wheel on every single closure.
[0018] As a consequence of these design constraints, it may become
complicated to adapt a sterilising unit of this type to closures of
a different size or with different characteristics (e.g. material
and, consequently, friction coefficient with respect to the guide
surfaces; a different minimum exposure time to the sterilising
agent, and so forth). Furthermore, difficulties could arise if the
plant productivity had to be increased, in that the settings
determining the star wheel actuation cycles would have to be
carefully revised. In other words, a sterilisation unit of this
type may not be fully satisfactory in terms of adjustability and
adaptability.
DISCLOSURE OF INVENTION
[0019] It is an object of the present invention to provide a
sterilising unit which makes it possible to overcome the above
drawbacks in straightforward and inexpensive fashion.
[0020] This object is achieved by a container closure sterilising
unit as claimed in claim 1.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] A non-limiting embodiment of the present invention will be
described in the following by way of example and with reference to
the accompanying drawings, in which:
[0022] FIG. 1 shows a schematic perspective exploded view of a
sterilising unit in accordance with the teachings of the present
invention;
[0023] FIG. 2 shows a larger-scale schematic plan view of a detail
of the sterilising unit of FIG. 1;
[0024] FIG. 3 shows a larger-scale perspective view of a detail of
the sterilising unit of FIGS. 1 and 2;
[0025] FIG. 4 shows a side view of an alternative embodiment of a
sterilising unit according to the invention; and
[0026] FIG. 5 shows a larger-scale front view of a detail of the
embodiment of FIG. 4.
BEST MODE FOR CARRYING OUT THE INVENTION
[0027] Number 1 in FIG. 1 indicates as a whole a container closure
sterilising unit, in particular for caps and stoppers to be applied
to relative containers, such as bottles.
[0028] Sterilising unit 1 comprises at least one closure treatment
station 2 and a device 3 for feeding a plurality of container
closures 100 (see FIGS. 2 and 3) to closure treatment station
2.
[0029] As illustrated in greater detail in FIG. 2, feeding device 3
comprises guiding means 4 defining: an entrance 5 for closures 100,
which entrance 5 communicates with loading means or a closure
storage unit (not shown) from which closures 100 to be sterilised
are supplied; a conveying path P comprising at least one linear
tract P1 (i.e. one tract having constant inclination relative to
the vertical direction) and along which the at least one treatment
station 2 is arranged; and an exit 6 for closures, which exit 6
communicates with a further unit (not shown) arranged downstream
from sterilising unit 1.
[0030] Advantageously, feeding device 3 comprises (see FIG. 2)
conveying means 7 operatively active on a single file of closures
100 to advance them towards treatment station 2 evenly spaced from
one another along conveying path P. In particular, conveying means
7 are operatively associated with guiding means 4.
[0031] Preferably, conveying means 7 comprise a helical coil (see
also FIG. 3) which is operatively active on a queue of closures 100
to cause said closures to advance along conveying path P and to be
fed to the at least one treatment station 2 evenly spaced from one
another along conveying path P.
[0032] In particular, a longitudinal axis H of helical coil 8
extends parallel to tract P1 of conveying path P. In the embodiment
of FIG. 3, helical coil 8 is born by a shaft 9 substantially
coaxial with coil 8 and driven by motor means 10. More
particularly, helical coil 8 is preferably fixed to shaft 9 by a
plurality of support elements 11 extending radially from shaft 9
and arranged evenly spaced along the latter. In turn, shaft 9 is
rotatably mounted at shaft end mount portions.
[0033] By virtue of operative association of conveying means 7 and
guiding means 4, rotation of helical coil 8 about its axis results
in the forward movement of all closures on which helical coil 8 is
operatively active.
[0034] In particular, it shall appear that constant speed rotation
of helical coil 8 results in the uniform forward movement of the
closures 100 upon which helical coil 8 is operatively active at a
constant linear speed along tract P1 of conveying path P. In other
words, upon cooperation with helical coil 8, closures 100 are all
advanced at the same speed along tract P1.
[0035] Although conveying means 7 are preferably driven by a
brushless-type electric motor, the use of driving means of a
mechanical type, e.g. by means of gears, represents a viable
alternative.
[0036] With particular reference to FIG. 2, guiding means 4
preferably comprise a plurality of guides 12. Guides 12 may, at
least for a portion thereof, be inclined relative to the horizontal
direction, so as to permit closures 100 to slide by gravity.
[0037] Preferably, as in the embodiment shown in FIG. 2, guides 12
comprise, in succession relative to an advancing direction of
closures 100 along path P, an input section 13, a main section 14
and an output section 15, each section being more inclined relative
to the horizontal direction than the previous one (relative to said
advancing direction of the closures). However, as shall become
clear in the following, alternative arrangements and inclinations
are also made viable by the present invention.
[0038] A container closure 100 such as a cap or stopper typically
has a substantially cylindrical shape extending along a respective
axis B. Accordingly, every container closure shall have a top
surface 101 substantially orthogonal to axis B and a lateral
(cylindrical) edge surface 102 substantially parallel to axis
B.
[0039] Guides 12 comprise, in particular (see FIG. 2): one or more
first guides 12' extending, at least along tract P1 of conveying
path P, parallel to shaft 9 and operatively active on the lateral
edge surface 102 of closures 100; and one or more second guides
12'' cooperating with the top surface 101 of closures 100.
[0040] In practice, the lateral edge surface 101 of closures 100
rest on the one or more first guides 12' which substantially
define, with shaft 9, a rail along which closures 100 may be
advanced.
[0041] On the other hand, closures 100 are substantially guided
between pairs of second guides 12'' arranged on opposite sides of
closures 100 (i.e. facing top and bottom sides of closures 100,
respectively) or between one or more second guides 12'', on one
side, and an opposite supporting wall, as will become apparent in
the following.
[0042] Where guides 12' are inclined relative to a vertical
direction, closures 100 may therefore roll by gravity along the
sections of guides 12' where there is no cooperation of closures
100 with helical coil 8.
[0043] Sterilising unit 1 further comprises an outer casing 16
adapted to house guiding means 4 and conveying means 7. In the
example illustrated, casing 16 comprises a shell portion 17 and a
cover portion 18, the shell portion being adapted to materially
house guides 12, helical coil 8 and shaft 9, and motor means
10.
[0044] With particular reference to FIG. 1, outer casing 16
comprises an input channel 19, a central body 20, and an output
channel 21, conveying means 7 and a section of the guiding means 4
being housed within central body 20.
[0045] Central body 20 has at least a first service window 22
positioned in the location of the closure treatment (i.e.
sterilisation) station 2 to enable treatment of the closures 100
travelling along path P as defined by the section of guiding means
4 housed within central body 20.
[0046] Preferably, central body 20 further comprises a second
service window 23 positioned opposite first service window 22, so
that closures 100 conveyed along path P by helical coil 8 can be
conveniently treated from both sides.
[0047] Input channel 19 typically communicates with the loading
means or closure storage unit (not illustrated) for storing and
feeding the closures to be treated.
[0048] In the embodiment illustrated in FIG. 1, sterilisation unit
1 comprises one or more sources 24,24' of ionising radiation, for
example emitters of electron beams or gamma or beta rays, each
arranged at a relative service window 22,23, positioned opposite
each other, the conveying path P along which closures are advanced
extending between them. In such a case, as illustrated in FIG. 1,
guiding means and conveying means are interposed between said pair
of emitters 24, 24', which irradiate closures 100 through the
respective windows 22,23 (only one of which is visible in the
drawings) of central body 20 of outer casing 16. Accordingly,
closures 100 may advantageously be treated on both their top and
bottom sides.
[0049] In a preferred embodiment, helical coil 8 is hollow (see the
detail of FIG. 3) and can advantageously be flown through by a flow
of a thermal carrier (e.g. cooling) fluid, like water. To this
purpose, a suitable inlet and outlet for the cooling fluid may
advantageously be provided at the ends of helical coil 8, e.g. at
the shaft end mount portions.
[0050] It should be noted that, in use, an electron beam emitter,
like other sources of ionising radiations typically employed for
sterilisation purposes, releases heat (e.g. thermal powers of about
500 W are common in the field). Accordingly, ablation of the heat
released at the at least one treatment station 2 is desirable, both
with a view to preventing any superheating of sterilisation unit 1
as a whole and--even more importantly so--to maintaining the
temperature of helical coil 8 within a predetermined range, so that
thermal expansion does not alter its geometry. As a matter of fact,
thermal deformation of helical coil 8 might result in operational
anomalies, what with alterations of the pitch between adjacent
convolutions of the coil making cooperation with closures 100
imprecise, not properly functional or even altogether
impossible.
[0051] Number 1.1 in FIG. 4 indicates as a whole an alternative
embodiment of a sterilising unit in accordance with the present
invention.
[0052] Sterilising unit 1.1 is similar to sterilising unit 1 and is
described below only insofar as it differs from the latter, and
using, wherever possible, the same reference numbers for identical
or corresponding parts of sterilising units 1 and 1.1.
[0053] More specifically, sterilising unit 1.1 differs from
sterilising unit 1 in that it comprises (see also the detail in
FIG. 5) a plurality of strengthening guide elements 31.1 extending
parallel to axis H and substantially tangential to the convolutions
of helical coil 8. Preferably, strengthening guide elements 31.1
are equally spaced about axis H. For example, in the embodiment of
FIG. 4, three strengthening guide elements 31.1 are provided at
120.degree. off one another.
[0054] In the embodiment shown, strengthening guide elements 31.1
extend along only part of helical coil 8, however they might run
parallel to helical coil 8 along the whole of its length.
[0055] Preferably, sterilising unit 1.1 further comprises a
rotating shielding portion 32.1 kinematically coupled with helical
coil 8 and extending coaxially to helical coil 8 at one end
thereof.
[0056] Helical coil 8 and the convolutions thereof shall be
designed and arranged, relative to guides 12 so that strengthening
guide elements 31.1 do not hinder proper interaction between the
convolutions of helical coil 8 and closures 100.
[0057] Strengthening guide elements 31.1 help preventing helical
coil 8 from deflecting or undergoing deformations due to thermal
expansion, thereby preserving optimal functionality of helical coil
8 itself.
[0058] It shall appear that this positive effect resulting from the
provision of strengthening guide elements 31.1 can be coupled with
that obtainable by having a cooling fluid flowing within a hollow
helical coil 8 as described above.
[0059] Operation of sterilising unit 1 (1.1) will now be briefly
described.
[0060] Closures 100 picked up from the loading means or a closure
storage unit slide along the section of the guides 12 arranged
within input channel 19, forming a single file along path P (see in
particular FIG. 1).
[0061] Helical coil 8 is rotated by motor means 10 about shaft 9,
the convolutions of helical coil 8 and guides 12 cooperating with
closures 100 to produce a forward movement of closures 100 along
tract P1 of conveying path P.
[0062] Helical coil 8 thereby imparts a uniform velocity along
tract P1 to all closures 100 reaching tract P1 and conveys them
across the at least one service window 22, where closures 100 are
conveniently exposed to the action of source 24 of sterilising
means (electron beam emitter or the like). By virtue of the
geometry of helical coil 8, closures 100 are maintained evenly
spaced from one another as they advance along tract P1 of conveying
path P. In fact, the convolutions of helical coil 8 contact
closures 100 substantially at a single point on their periphery.
Therefore, friction and the possible consequent local formation of
powder or dust are advantageously greatly reduced. Furthermore,
since closures 100 are separated from one another by a respective
convolution of helical coil 8 and loosely cooperate with adjacent
convolutions of helical coil 8 and with guides 12, a rolling
movement of closures 100 (i.e. rotation about their axis B) is
induced, as they advance towards output channel 21. As a
consequence of said rolling movement, the formation of shadow zones
may very advantageously be prevented.
[0063] The speed at which closures 100 advance along tract P1 of
conveying path P is conveniently and uniformly controlled by
controlling solely the rotation speed of shaft 9, independent of
inclination of guides 12 and of the characteristics of the closure
material (e.g. friction coefficient, density and so on).
[0064] A cooling fluid, such as water, may be directed to flow
within helical coil 8 for removing any excess heat generating by
the sources 24 of ionising means.
[0065] The advantages of sterilising unit 1 according to the
present invention will be clear from the above description.
[0066] In particular, sterilising unit 1 according to the invention
prevents the formation of shadow zones between closures 100,
whereby a complete and safe sterilisation treatment of the closures
is made possible. Furthermore, by controlling solely the speed of
rotation of conveying means 7 (helical coil 8) it is possible to
have the closures advance along path P evenly spaced by a
predetermined pitch and at a uniform given speed. Accordingly, all
closures may uniformly be exposed to the source 24 of sterilisation
means for the same treatment time and under substantially
equivalent treatment conditions. In particular, the duration of the
treatment may be conveniently adjusted in use. Furthermore, since
the speed at which closures 100 are advanced along tract P1 of
conveying path P, i.e. along the section of path P materially
relevant to the sterilisation process, is controlled univocally by
conveying means 7, independently of the inclination of guides 12
relative to the vertical direction, a great number of design
alternatives become available, making it possible for the designer
to adapt the sterilisation unit to different geometries and space
constraints. As a matter of fact, tract P1 might even be arranged
horizontally or vertically.
[0067] Advantageously, the sterilisation unit of the invention
makes it possible to adjust the speed at which closures are
advanced along path P on the basis of plant productivity
requirements, e.g. as a function of the number of bottles capped
per hour.
[0068] Furthermore, the sterilising unit of the invention can
operate with closures of different materials without requiring that
parameters such as the speed of rotation of helical coil 8 be
adjusted from time to time, since properties such as the friction
coefficient between closures 100 and guides 12 has no influence on
the time of exposure to the sources 24 of sterilisation means.
Besides, replacement of helical coil 8 with a modified coil adapted
to cooperate with smaller/larger closures would be enough to make
sterilisation unit 1 functionally operable with closures 100 of a
different size.
[0069] Clearly, changes may be made to sterilising unit 1 as
described and illustrated herein without, however, departing from
the scope of protection as defined in the accompanying claims.
* * * * *