U.S. patent number 3,783,581 [Application Number 05/245,112] was granted by the patent office on 1974-01-08 for aseptic packaging method and machine.
This patent grant is currently assigned to Dart Industries Inc.. Invention is credited to Joseph E. Pierce.
United States Patent |
3,783,581 |
Pierce |
January 8, 1974 |
ASEPTIC PACKAGING METHOD AND MACHINE
Abstract
An apparatus for aseptically packaging food and other products
includes a housing which defines an enclosed sterile chamber and
contains an endless conveyor having an upper flight adapted to
transport individual containers through a plurality of operating
stations. The housing is formed with a container sterilization
section located adjacent one end of the conveyor and has a
container dispenser mechanism mounted therein which holds
individual containers in this section for a predetermined period of
time and thereafter dispenses the containers on the upper flight of
the conveyor; the latter transports the containers to a filling
station where a sterile product is placed in the container.
Downstream of the filling station, a continuous strip of
interconnected covers is sequentially advanced, through a cover
sterilization section formed in the housing, into position in
registry with the containers on the conveyor. Thereafter, the
covers are heat sealed to the containers and discharged from the
housing. The entire sterile chamber is supplied with a sterile
atmosphere at a pressure above atmospheric pressure to maintain the
containers and covers in a sterile condition during the filling and
cover sealing operation.
Inventors: |
Pierce; Joseph E. (Allentown,
PA) |
Assignee: |
Dart Industries Inc. (Los
Angeles, CA)
|
Family
ID: |
22925339 |
Appl.
No.: |
05/245,112 |
Filed: |
April 18, 1972 |
Current U.S.
Class: |
53/426; 53/167;
53/478; 53/282; 53/471 |
Current CPC
Class: |
B65B
55/027 (20130101); B65B 55/10 (20130101); B29C
2793/0036 (20130101) |
Current International
Class: |
B65B
55/04 (20060101); B65B 55/02 (20060101); B65B
55/10 (20060101); B65b 031/02 () |
Field of
Search: |
;53/37,40,41,51,112R,141,167,184,281,282,329 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Spruill; Robert L.
Attorney, Agent or Firm: Hovet; Kenneth J. Taylor; Leigh B.
Wylie; Paul R.
Claims
What is claimed is:
1. Apparatus for aseptically packaging food, drugs and other
products comprising, a housing defining an enclosed sterilization
chamber, an endless conveyor mounted completely within said housing
and having upper and lower flights and means thereon for receiving
containers to be filled; a plurality of operating stations located
along one of said flights and drive means for sequentially moving
said conveyor along said flights between sid operating stations,
said housing including a container sterilization section located at
a first station therein and container dispenser means mounted in
said container sterilization section at said first station for
holding containers in said container sterilization section
comprising a vertically extending endless conveyor having a
downwardly moving flight located above the first mentioned endless
conveyor at said first station and a plurality of container support
platforms secured thereto and extending horizontally therefrom
along said downwardly moving flight, including container supply
means mounted on said housing adjacent the upper end of said
downwardly moving flight for supplying individual containers to
said platforms, and said vertically extending conveyor holding said
individual containers in said container sterilization section for
said predetermined time as said containers are moved from said
container supply means to said first station whereby said
containers are sterilized prior to being deposited on said first
mentioned conveyor; filling means mounted on said housing at a
second station, downstream of said first station in the direction
of travel of said conveyor, for filling each container on said
conveyor with a sterilized product; said housing also including a
cover sterilization section of predetermined length located at a
third station therein downstream of said second station; means for
sequentially advancing a continuous strip of interconnected die cut
covers through said cover sterilization chamber to said third
station in timed relation with the arrival of containers at said
third station to sequentially position said covers over said
containers in registry therewith, means at a fourth station,
downwstream of said third station, for securing said covers to said
containers as the containers are sequentially moved to said fourth
station by said conveyor, means at a fifth station, downstream of
said fourth station for moving the covered containers from said
conveyor and discharging them from said housing, and means for
supplying a sterile atmosphere to said housing at a pressure above
atmospheric pressure to maintain said containers and covers in a
sterile condition during movement through said operating
stations.
2. Apparatus as defined in claim 1 wherein said means for supplying
a sterile atmosphere comprises means for supplying dry
high-temperature steam to said sterile chamber.
3. Apparatus as defined in claim 2 wherein said means for supplying
a sterile atmosphere includes means for maintaining higher
temperatures in said container and cover sterilization sections
than in the remainder of said housing whereby said containers and
covers are sterilized in said sterilization sections prior to
placement on said conveyor.
4. Apparatus as defined in claim 1 including means cooperating with
the covers in said strip of covers for individually registering
each of said covers with its associated container.
5. Apparatus as defined in claim 4 including means mounted in said
housing between said fourth and fifth stations for severing the
interconnection between individual covers in said strip of covers,
after said covers are secured to the containers.
6. Apparatus as defined in claim 5 including means for sequentially
supplying individual containers to said container holding and
depositing means.
7. Apparatus as defined in claim 5 wherein said means for
sequentially advancing said strip of die cut covers includes a reel
supporting a roll of said strip of covers, means for guiding said
strip along a predetermined path in said cover sterilization
chamber from said reel to said third station whereby said covers
are maintained in said sterilization chamber for a period of time
sufficient to sterilize the covers, and means at said third station
for unwinding said strip from the reel, drawing the strip along
said predetermined path and sequentially directing each cover as it
is advanced to said third station over a container which is
sequentially advanced to said third station by said conveyor.
8. Apparatus as defined in claim 5 wherein said covers have a heat
sealing coating on the side thereof positioned in contact with said
containers and said means for securing said covers to said
containers comprises heat sealing means for heating and pressing
the heat sealing coating on said cover against the adjacent
portions of said container.
9. Apparatus as defined in claim 8 including means at said fourth
station, immediately downstream of said heat sealing means, for
cooling the heat sealed cover and pressing the cover against the
container, thereby to maintain the bond formed by said heat sealing
means and cool it to its solidification temperature.
10. Apparatus as defined in claim 5 wherein said container
receiving means on said conveyor has a plurality of apertures
therein for receiving and supporting said containers, said conveyor
having a discharge end located at said fifth station and said means
for removing the covered containers from said conveyor comprising
an auxiliary endless conveyor located between the flights of the
first mentioned conveyor and having one end located on a common
axis of rotation with the discharge end thereof, said auxiliary
conveyor having an inclined upper flight portion approaching said
first mentioned conveyor at the discharge end thereof and having a
plurality of projections thereon for engaging the bottoms of said
containers supported in said openings and lifting them therefrom at
said discharge end.
11. Apparatus as defined in claim 10 including a pair of fixed
support rods mounted in closely spaced relation to each other and
having one end thereof located adjacent said discharge end of said
first mentioned conveyor for receiving said lifted containers
therebetween and guiding them from said discharge end.
12. Apparatus as defined in claim 11 wherein said housing has an
opening therein through which said rods extend to permit removal of
said containers from said housing.
13. Apparatus as defined in claim 4 wherein said strip of covers
includes an interconnecting portion between each pair of adjacent
covers and formed integrally therewith, said interconnecting
portion including a flat section and a corrugated section
selectively adapted to expand or contract, said flat section having
an aperture therein and said means for individually registering
said covers with their associated container comprising individual
upstanding pins on said endless conveyor respectively adjacent said
container receiving means for engagement in said apertures.
14. Apparatus for aseptically packaging food, drugs and other
products, comprising, a housing defining an enclosed sterile
chamber, an endless conveyor mounted completely within said housing
and having an upper flight for transporting containers through said
housing; said housing having a container sterilizing section
located adjacent one end of said conveyor and a container dispenser
means mounted in said section including a vertically extending
endless conveyor having a plurality of container support platforms
secured thereto for holding containers therein for a predetermined
period of time and thereafter depositing the containers on said
upper conveyor flight, means in said housing, downstream of said
container sterilization section in the direction of travel of said
conveyor, for sequentially filling containers on the conveyor with
a sterilized product; said housing also including a cover
sterilization section having a predetermined length and means
mounted in said cover sterilization section for sequentially
advancing a continuous strip of interconnected covers through said
cover sterilization chamber and for sequentially positioning said
covers over said containers in registry therewith downstream of
said filling means; means for thereafter securing said covers to
said containers, and means for supplying a sterile atmosphere to
said enclosed sterile chamber at a pressure above atmospheric
pressure to maintain said containers and covers in a sterile
condition during the filling and cover securing operations.
15. Apparatus as defined in claim 14 including means downstream of
said sealing means for severing the interconnection between
individual covers in said strip after said covers are secured to
the containers.
16. Apparatus as defined in claim 15 including means downstream of
said severing means for removing covered containers from said
conveyor and discharging them from said housing.
17. Apparatus as defined in claim 14 wherein said means for
supplying a sterile atmosphere includes means for maintaining a
higher temperature in said container and cover sterilization
sections than in the remainder of said sterile chamber whereby said
containers and covers are sterilized in said sterilization sections
prior to placement on the conveyor.
18. Apparatus as defined in claim 17 wherein said covers have a
heat sealing coating on the side thereof positioned in contact with
said containers and said means for securing said covers to said
containers comprises heat sealing means for heating and pressing
the heat sealing coating on said cover against the adjacent
portions of said container.
19. Apparatus as defined in claim 18 including means immediately
downstream of said heat sealing means for cooling the heat sealed
cover and pressing the cover against the container thereby to
maintain the bond formed by said heat sealing means and cool the
bond to its solidification temperature.
20. Apparatus as defined in claim 18 wherein said means for
supplying a sterile atmosphere comprises means for supplying dry
high temperature steam to said sterile chamber.
21. Apparatus for aseptically packaging food, drugs and other
products, comprising, a housing defining an enclosed sterile
chamber, an endless conveyor mounted completely within said housing
and having an upper flight for transporting containers through said
housing; means in said housing for depositing individual sterilized
containers on said upper conveyor flight, means, downstream of said
depositing means in the direction of travel of said conveyor, for
sequentially filling containers on the conveyor with a sterile
product; transport conveyor means including an endless feed belt
for sequentially advancing a continuous strip of interconnected
sterile covers into position over the filled containers in registry
therewith downstream of said filling means, pin means on said
endless conveyor cooperating with the covers in said strip for
individually registering each of said covers with its associated
container; means for thereafter securing said covers to said
containers, and means for supplying a sterile atmosphere to said
enclosed sterile chamber at a pressure above atmospheric pressure
to maintain said containers and covers in a sterile condition
during the filling and cover securing operations.
22. Apparatus as defined in claim 21 wherein said strip of covers
includes an interconnecting portion formed between each pair of
adjacent covers and formed integrally therewith, said
interconnecting portion including a flat section and a corrugated
section selectively adapted to expand or contract, said flat
section having an aperture therein for engagement with said pin
means.
23. A method for aseptically packaging food, drugs and other
products comprising: supplying individual containers to an enclosed
container sterilization section; holding said containers within
said section for a time sufficient to effect sterilization thereof;
and thereafter transporting said containers through a plurality of
operating stations within a sterilization housing including;
filling said containers at a first station in said housing with a
sterile product, supplying a continuous strip of interconnected
covers to an enclosed cover sterilization section, sterilizing said
covers in said sterilization section and, at a second station,
positioning said covers over said containers and in registry
therewith, securing said covers to said containers at a fourth
station and supplying a sterile atmosphere to said housing at a
pressure above atmospheric pressure to maintain said containers and
covers in a sterile condition during the filling and cover securing
operations.
24. The method as defimed in claim 23 including the step of
severing the interconnection between individual covers in said
strip after said covers are secured to said containers.
25. The method as defined in claim 24 including the step of
removing the covered containers from said housing after said
severing step.
26. The method as defined in claim 25 wherein said covers have a
heat sealing coating on the side thereof positioned in contact with
said containers and said securing step comprises the step of heat
sealing said covers to said containers.
27. The method as defined in claim 23 wherein said container and
cover sterilization sections are maintained at a higher temperature
than said housing.
Description
The present invention relates to aseptic packaging of food, drugs
and other products, and in particular, to an apparatus for
sterilizing containers and covers, filling the containers with a
sterile product, and securing the covers to the containers, all
within a single sterile enclosure.
A number of previous attempts have been made to provide aseptic
packaging apparatus in which a sterile food product or the like is
placed in containers and enclosed to preserve the product for later
use. However, none of these prior attempts has been completely
successful because heretofore it has not been possible to
completely eliminate the risk of recontamination of the food
product or the container during the filling and closing operations.
As a result, it has been found necessary to carry out a
re-sterilization of the filled container in order to insure the
complete elimination of contaminating bacteria in the container or
the food product prior to storage and shipment. This
re-sterilization represents an additional expense in the packaging
process and, because of the generally high temperatures required
for the re-sterilization, the quality and taste of food products
are often detrimentally affected thereby.
Accordingly, it is an object of the present invention to sterilize,
fill and seal a container for a food product and the like in a
single sterile enclosure so as to eliminate the requirement for
re-sterilization after completion of the packaging operation.
Yet another object of the present invention is to provide an
apparatus which will package sterile food products and the like
under sterile conditions in a single enclosure and which is
relatively inexpensive in construction and durable in use.
Yet another object of the present invention is to package food
products and the like under sterile conditions in which the
possibility of contamination of the products during the packaging
operation is substantially eliminated.
In accordance with an aspect of the present invention an apparatus
for aseptically packaging food, drugs and other products, under
sterile conditions, is provided in which an enclosed sterilization
chamber, formed from a substantially air-impervious housing, has an
endless conveyor mounted entirely therein for sequentially moving
containers to be filled through a plurality of operating stations
located along one of the flights of the conveyor. The housing
includes a container sterilization section located at a first
station therein to which individual containers are supplied. A
container dispenser is mounted in the container sterilization
section and receives the individual containers and deposits them on
the conveyor. The container dispenser holds the containers in the
sterilization chamber for a predetermined period of time, as the
container is moved towards the conveyor from the point at which it
is supplied to the sterilization chamber, so that the container is
sterilized immediately prior to being placed on the conveyor.
Once the containers are on the conveyor, they are moved to a second
station in the housing at which a filling device is mounted to fill
the containers with a sterile food product or the like, as they are
sequentially presented at this station. Downstream of the filling
station, the housing is formed with a cover sterilization section
having a predetermined length and containing means for sequentially
advancing a continuous strip of interconnected die cut covers from
a point of entry into the housing to a position over the containers
and in registry therewith. The length of the cover sterilization
section is so selected that the time taken for movement of an
individual cover from the point of entry into the housing to the
point of application to the filled container is sufficient for the
covers to be completely sterilized and all bacteria thereon
destroyed.
From the point of application of the covers to the containers, the
containers are sequentially moved by the conveyor to a cover
sealing station located within the enclosure at which means are
provided for heat sealing the cover to the container. Thereafter,
the conveyor moves the sealed container to a station at which the
interconnection between the container lids is severed and thence to
a discharge apparatus which removes the separated containers from
the conveyor and discharges them from the enclosure.
The entire sterile chamber is supplied with a sterile atmosphere
such as, for example, dry, high-temperature steam or superheated
air, so that each of the packaging operations is performed under
sterile conditions and the container and cover are sterilized and
maintained sterile as part of the packaging operation itself. The
sterile atmosphere is supplied at a pressure above atmospheric, so
that sterile air will leak out of the chamber through any openings
in the housing, thereby preventing any non-sterile air surrounding
the packaging apparatus from entering the sterile chamber.
The above, and other objects, features and advantages of this
invention, will be apparent in the following detailed description
of an illustrative embodiment thereof which is to be read in
connection with the accompanying drawings, wherein:
FIGS. 1A and 1B together comprise a sectional elevation view of an
aseptic packaging apparatus constructed in accordance with an
embodiment of the present invention;
FIG. 2 is a plan view of a portion of the container transport
conveyor shown in FIG. 1;
FIG. 3 is a plan view of a portion of a strip of covers adapted to
be utilized in conjunction with the present invention;
FIG. 4 is an elevational view of the cover strip in FIG. 3; and
FIG. 5 is a plan view, similar to FIG. 3, of another embodiment of
covers which are suitable for use with the present invention.
Referring to the drawing in detail, it is seen that an aseptic
packaging apparatus 10, embodying the present invention, includes a
substantially air-impervious outer housing 12 which defines an
enclosed sterile chamber 14 in which the packaging operations are
performed. Housing 12 is supported in any desired manner, as for
example by legs 16 located at the corners of the housing, and has
an endless chain type conveyor 18 rotatably mounted therein for
transporting individual containers through a plurality of operating
stations located within chamber 14.
A sterile atmosphere is supplied to chamber 14 from a supply system
20 mounted on the lower portion of housing 12 and separated from
chamber 14 by an air-impervious horizontal panel 22. The sterile
atmosphere may be either dry high temperature steam or superheated
air, with the water or air being supplied from a source thereof
(not shown) to a heat exchanger coil 24 mounted within the chamber
26 defined by supply system 20. A conventional gas manifold 28 is
mounted below heat exchanger coil 24 and the combustion products of
the burning gases transfer the heat of the combustion to the water
or air contained within heat exchanger coil 24 by conduction to
heat the water or air in the coil to temperatures sufficiently high
enough to kill bacteria in chamber 14. The steam or air thus heated
flows from coil 24, at outlet 29, and is distributed within chamber
14 by a plurality of discharge manifolds 30. As more fully
described hereinafter, the sterile atmosphere is supplied to
chamber 14 at a pressure slightly above atmospheric.
Conveyor 18 is similar in construction to the conveyor disclosed in
my copending patent application Ser. No. 53,947, filed July 10,
1970 now U.S. Pat. No. 3,694,997, the disclosure of which is
incorporated herein by reference, and is formed from a pair of
endless edge chains 32 (FIGS. 1 and 2), which extend around pairs
of spaced drive and driven sprockets 34, 36 respectively. Chains 32
are spaced apart a predetermined distance and are interconnected by
a plurality of flights or panels 38 having openings 39 therein for
the reception of containers to be filled. The drive to conveyor 18
may be through a chain and sprocket system from a drive motor (not
shown) mounted at the base of the apparatus, or by any convenient
drive system such as would be clear to those skilled in the
art.
Conveyor 18 provides upper and lower flights 40, 42 respectively,
with upper flight 40 moving towards the right in FIGS. 1A and 1B,
passing a loading station 44 adjacent sprocket 34. Directly above
loading station 44, housing 12 is formed to define a container
sterilization section 46 in which individual containers 48 are held
for a predetermined period of time sufficient for the temperature
of the containers to be raised above a predetermined level, such as
for example 350.degree. F, at which all possible contaminating
bacteria or the like on the containers are destroyed.
Individual containers 48 are supplied to sterilization section 46
from a container storage hopper 50 mounted on housing 12 and are
sequentially dispensed from the hopper to a platform 52 by a
dispensing unit 54. The dispensing unit may be of conventional
construction for supplying individual containers to the platform 52
in housing 12 and, in one embodiment of the invention, is
constructed in a manner similar to the dspensing unit described in
my above-mentioned patent application.
From platform 52 the individually dispensed containers 48 are
supplied to a conveyor 56 mounted within sterilization chamber 46.
Conveyor 56 is formed from a pair of spaced endless chains 58, only
one of which is seen in the drawing, having a plurality of L-shaped
platform members 60 pivotally connected thereto at the free ends 62
of their short legs. By this arrangement, it is seen that the long
leg 64 of platform 60 will be located in a generally horizontal
position along the downwardly moving flight 66 of conveyor 56. As a
plaftorm 60 is presented in position adjacent platform 52, the
individual containers 48 on the platform are moved onto platform 60
by a pneumatic or hydraulic ram 68. The latter has a pusher head 70
secured to its actuator rod 72 and is operated in synchronization
with conveyor 56 so that containers 48 are moved towards conveyor
56 only when a platform 60 is adjacent platform 52. After a
container 48 has been placed on platform 60, conveyor 56 is
operated to move the next platform 60 into position adjacent
platform 52. Simultaneously, and in synchronization therewith,
dispenser unit 54 releases another individual container from the
hopper 50 onto platform 52 and the sequence of operation is
repeated.
It is noted that while only a single row of containers 48 is shown
in FIG. 1, it is to be understood that one or more parallel rows of
containers can be treated at the same time. That is, a series of
container hoppers may be mounted adjacent each other, so that two
or more cups are placed on platform 52, next to each other, and
moved onto platforms 60 for simultaneous, side by side passage
through apparatus 10, with each of the components in the apparatus
being duplicated for each row of cups. In this manner, a plurality
of cups may be treated at the same time within the single housing
12. Thus, for example, conveyor 18 has been illustrated in FIG. 2
as having two adjacent openings 39 in each flight 38 for
simultaneously transporting two rows of containers through the
apparatus. Further, while the specific mechanical drive systems for
operating the various components of the present apparatus in
synchronization have not been illustrated, the specific mechanisms
form no part of the present invention and a variety of
synchronization systems such as would occur to those skilled in the
art may be utilized to drive the present apparatus.
Referring again to the drawing, as a platform 60 approaches the
lower sprockets 74 (only one of which is seen in FIG. 1A) of
conveyor 56, the platform begins to tilt about its pivotal
connection 62 because of the movement of its center of gravity
about the end sprocket. As the platform was moving down the
vertical flight 66 of the conveyor, its rear edge portion 68 rested
against the conveyor chains to support containers 48 in a
horizontal position; however, as conveyor chains 58 move away from
the rear edge of platform 60, i.e. as they move about sprockets 74,
the center of gravity of platform 60 causes it to tilt. As a
result, a container 48 on the platform slides therefrom under the
influence of gravity. At the same time a flight 38 of conveyor 18
is presented at station 44 with its opening in location to receive
the discharged container. Conveyor 18 is driven in synchronism with
conveyor 56 in any convenient manner so that the synchronous
arrival of platform 60 and a flight 38 of the conveyor is
assured.
In this manner a sterilized container is supplied to conveyor 18 at
station 44. The container is supported in the opening 39 in a
flight 38 by its rim 49 and is sequentially moved from station 44
to a second operating station 80 by the conveyor. At this operating
station a sterile feed system 82 is provided for automatically
filling containers 48 presented at the station with a sterile food
product, drug or the like. The filling system may be of a known
construction such as for example, the "Apparatus for Dispensing
Viscous Materials" disclosed in my copending application Ser. No.
846,742, filed Aug. 1, 1969 and now abandoned, and is operated in
synchronism with conveyor 18 so that as a container 48 is presented
at filling station 80, a predetermined supply of food or the like
is automatically dispensed into the container. It is noted that the
food product supplied to the sterile feed system 82 is supplied in
a sterile condition from its point of manufacture through a closed
supply system or conduit 84 so that it is sterile when released
into container 48 by the feed system. Since the containers 48 and
the atmosphere in chamber 14 are both sterile, there is no chance
for the food to become contaminated in any way as it is dispensed
into the containers.
Continuing from filling station 80, conveyor 18 sequentially moves
the now filled containers 48 to a cover dispensing station 86
located downstream of the filling station with respect to the
direction of travel of the conveyor. At station 86 housing 12 is
formed with a cover sterilization chamber 88 of predetermined
length, for reasons more fully described hereinafter.
Cover sterilization section 88 has an opening 90 (FIG. 1B) formed
at its uppermost end through which a continuous strip of
interconnected covers 92 pass from a rotatably mounted supply reel
94. Covers 92 are preferably formed as die cut covers having a
peripheral configuration conforming to the peripheral configuration
of the lip 49 of containers 48 with each of the covers
interconnected in a strip by integral connecting portions 93, as
seen in FIG. 3. Alternatively, the covers may be formed as a strip
of aluminum foil or the like. In either case, the underside of the
covers, that is, the side thereof which is to be in contact with
the containers is treated with a heat sealable material or
adhesive, for securing the cover to the container as described
hereinafter.
From reel 94, the continuous strip of covers 92 is guided over a
pair of rollers 98 and across a print roller 100 which is adapted
to place an indentification code and/or date on the external
surface of each lid in succession. From print roller 100, the strip
fed covers pass through aperture 90 into housing 12 to a transport
conveyor system 102. This system includes an endless feed belt 104
positioned about a plurality of rollers 106 and an unwinding roller
108 contained within sterilization section 88. Belt 104 has a
plurality of teeth or pins 110 thereon which engage the edges of
the covers in strip 92 and hold them to belt 104 for movement
therewith to cover dispensing station 86.
Dry steam and/or superheated air is supplied to sterilization
section 88 from system 20 through a pair of manifold members 30 in
order to sterilize the covers in the supplied strip 92. The height
or length of section 88 is predetermined so that the length of time
taken for an individual cover to move from opening 90 to the point
at which it is dispensed, i.e. adjacent unwinding roller 108, is
sufficient for the temperature of the lids to be raised to a level,
preferably 350.degree. F, at which all contaminating bacteria on
the covers are destroyed, so that the covers are thus
sterilized.
Unwinding roller 108 is driven in synchronization with conveyor 18
from the main power source of the apparatus so that individual
covers on the strip 92 are presented at station 86 in synchronism
with containers 48 and individual covers are moved into position
over the containers 48 in registry therewith.
The use of the pinned conveyor belt 104 for guiding cover strips 92
through the sterilization section 88 is advantageous since the belt
provides a self threading feature such that when a new supply reel
94 is utilized in the apparatus the free end of the strip 92
thereon is merely placed through opening 90 and the first cover is
automatically engaged by the teeth or pins 110 on the belt to hold
the cover strip against belt 104 and guide it into position at
station 86. To assist in the self threading operation a plurality
of guide plates 111 are mounted in sterilization section 88 to
guide the free edge of the cover strip about the curves in the
conveyor during the initial threading operation. In this manner any
necessity of opening housing 12 to the atmosphere in order to
thread the cover strip over unwinding roller 108 is eliminated. As
a result, the apparatus need not be resterilized when a new supply
of covers is initially supplied to the apparatus. On the other
hand, it is contemplated that belt 104 may be eliminated and roller
108 provided with pins 110 in lieu thereof to hold strip 92 and
guide it into position adjacent containers 48.
In a presently preferred embodiment of the invention a relatively
simple system is provided to assure that each cover 92 is
accurately positioned in registry with its associated container 48.
To this end the interconnecting portions 93 between covers 92 in
the strip of covers are formed with two integral section 93a and
93b respectively, as seen in FIG. 3. Section 93a is coplanar with
its adjacent cover 92 (i.e. the cover behind it in the direction of
travel of the strip) and has an aperture 93c formed therein, while
section 93b is crimped or corrugated so that it has the capacity to
readily expand or contract. Apertures 93c are accurately located in
the connecting portions 93 with respect to their associated cover
92 and are adapted to be engaged with the upright pins 39a mounted
on conveyor flights 38 adjacent apertures 39. Thus, as the covers
92 are moved into position over the containers 48 on conveyor 18
the apertures 93c become engaged with and receive pins 39a to
insure that their associated cover 92 (i.e. the cover to the left
of the apertures 93c in FIG. 3) is properly positioned on its
associated container. To facilitate the engagement of pins 39a in
apertures 93c, the pins may be formed as frustroconical members so
as to compensate for errors in the tolerance permitted between the
aperture and the pins.
In the event that the length of the connecting portion 93 is either
too short or too long to allow exact registry of cover 92 with its
associated container it will be appreciated that the deficiency or
excess in such length will be accommodated by the expansion or
contraction of its corrugated section 93b, which is now located
between the pin 39a and the previously positioned cover 92 since
engagement of pin 39a in aperture 39c will cause the cover 92, and
thus straight section 93a, to shift to the right or left in the
drawing when registry therebetween is improper. Accordingly, any
tolerance errors in the exact permissible spacing between covers 92
is automatically compensated for as each cover is placed on the
container. Of course, it will be recognized that this is an
important feature of the present apparatus since without it, an
error in tolerance between the spacing of even one pair of covers
on the strip will cause the latter cover of the pair to be
positioned out of exact registry with its associated container.
This lack of registry or misalignment then becomes additive for
each successive container being covered and therefore, even with
only a slight variation of tolerance, the covers ultimately would
be placed on the containers with complete lack of registry. By the
provision of tolerance compensations between each successive cover,
as described above, this problem is avoided.
In another embodiment of the invention, shown in FIG. 5, the
positions of the corrugated sections 93b and straight sections 93a
of the cover strip are reversed. In this case when a pin 39a
becomes engaged in aperture 93c, it will force the cover in front
of it (in the direction of travel) to move into registry with its
container, thereby expanding or contracting the corrugated section
93b' on the opposite side of the cover.
From station 86, containers 48, with the cover strip 92 placed on
top of and in registry therewith, are moved to a sealing station
112 at which the covers are secured to the containers. Station 112
includes a conventional electrically heated heat sealing head 114
slidably mounted through an opening 116 in housing 12. Head 114 is
connected to the actuator rod 118 of a hydraulic or pneumatic ram
12o which is operated in synchronism with conveyor 18 so that head
114 is lowered into contact with cover strip 92 when a container 48
is moved into position by conveyor 18. A rim 122 is preferably
formed on head 114, which rim conforms in peripheral configuration
to the periphery of the cover and the periphery of the container,
so that heat and pressure are applied to the edges of the cover and
lip 49 of the container. As a result, the heat sealable adhesive
applied on the surface of the cover, as described above, is heated
and pressed into engagement with the container to form a heat seal
therebetween.
The cover which is thus heat sealed to container 48 provides a
flawless seal for the contents of the cup which can withstand
considerable abuse in handling, but which may readily be broken
upon removal of the cover from the container. This type of a cover
for containers is a substantial improvement over those previously
proposed and utilized with sterile packaged food products. Such
previously proposed arrangements are the conventional metallic pull
tab type which have a weak resistance to shock and are susceptible
to rupture of the score line along the top. In addition, such tops
are dangerous since children apparently tend to lick these tops and
are often cut by the sharp edges thereof. With the covers utilized
in the aseptic packaging apparatus of the present invention, the
heat seal has a greater resistance to the shock and the cover is
approximately 1 percent container less in cost than the
conventional tab top arrangements. Moreover, there are no sharp
edges to cut children licking such covers.
Immediately downstream of heat sealing head 114, a cooled platen
126 is mounted for sliding movement in an opening 128 in housing
12. Platen 126 is mounted on the free end of the actuator rod 130
of a hydraulic or pneumatic ram 132 which serves to reciprocate the
platen with respect to the containers and caps. A continuous supply
of water or the like is passed through heat exchanger conduits 134
in the platen to cool it during use.
As a container 48 with a heat sealed cover secured thereto is
presented beneath platen 126, the platen is moved downwardly by ram
132 into contact therewith. The cooled platen serves to maintain
the cover in contact with the container and to cool the bond
therebetween to the solidification temperature of the sealant
material on the lid coating so that a flawless airtight seal is
formed. The cooled platen is required because of the relatively
high temperatures maintained within chamber 14 in order to maintain
sterile conditions therein. That is, without platen 126 there would
be the possibility that the seal would not fully solidify before
the container 48 is discharged from the sterile enclosure. Thus,
the cooled platen assures this solidification and completion of the
seal prior to discharge from the sterile chamber. As a result, no
resterilization of the container is required on completion of the
packaging operation. Moreover, since the covers on strip 92 are
still interconnected at this point in the operation, it is seen
that the motion of conveyor 18 is transmitted through containers 48
to the cover strip 92, thereby to draw the strip with the
conveyor.
A cutting station 136 is provided within housing 12 downstream from
cooling platen 126. Station 136 includes a reciprocating knife
member 138 which serves to sever the interconnection 93 between the
covers on strip 92 along the line 95 shown in FIGS. 3 and 5. As a
result each interconnection 93 after the severing operation remains
integral with one of the covers 92 and forms an extension tab which
is utilized to remove or strip the cover from the container when
the food or product within the container is to be used. Knife 138
is reciprocated in timed relation with the movement of conveyor 18
so that the interconnection 93 between each of the containers is
severed in sequential relation. The mechanism for driving knife 138
in this relation is a relatively simple conventional mechanical
movement which would be readily understood by those skilled in the
art. It forms no part of the present invention, and therefore, is
not described herein in detail.
At this point the filling operation is completed and the containers
are ready for discharge from sterile chamber 14. To this end, a
discharge conveyor system 150 is provided at the right end of
conveyor 18. Conveyor system 150 includes an auxiliary belt
conveyor 152 mounted between the flights of conveyor 18 and having
one end thereof mounted on a roller 151 coaxially with the driven
gear 36. The other end of conveyor 152 is positioned about a roller
153 of smaller diameter than roller 151 to form an inclined
conveyor portion 154 which approaches conveyor 18 at a point
adjacent the discharge end 156 thereof.
Belt 152 includes a plurality of lifting projections 158 on its
exterior surface, which projections are spaced along the belt at
distances equal to the distance between successive containers 48 in
conveyor 18. As seen in the drawing, as projections 158 move to the
right with belt 152, they engage the bottoms 160 of containers 48
and lift the containers from the openings 39 in flights 38 until
the containers are substantially completely lifted from the
flights. Conveyor 152 is driven in synchronism with conveyor 18 to
insure that projections 158 will always contact the bases 160 of
the containers.
To finally remove containers 48 from conveyor 18, a pair of fixed
support rods 160 are mounted on housing 12 in spaced relation to
each other. Although only one of the rods is seen in the drawings,
it is to be understood that the rods are spaced adjacent each other
a distance equal to the diameter of the containers 48, with their
rear ends 162 projecting into chamber 14 through an opening 164 in
housing 12. As conveyor 18 moves containers 48 about sprocket 36,
the containers, having been lifted by projections 158, pass between
the ends 162 of rods 160 and the undersides of their lips 49 are
engaged by the rods. As a result, the containers rest on rod ends
162 and are fully removed from their associated conveyor flight 38
as it moves about sprockets 36. Rods 160 are inclined so that
containers 48 will, under the influence of gravity, slide between
the rods and be guided thereby to the exterior of the housing where
they are discharged at the front ends 166 of rods 160 onto a
discharge conveyor 168 for further packaging and shipment.
The sterile atmosphere supplied to enclosure 14 from supply system
20 maintains the equipment, containers and food within the
container in a sterile condition and prevents contamination thereof
during the packaging operation. Substantially all of the sterile
atmosphere supplied to chamber 14 passes from the nozzles 31 in the
manifolds 30 located adjacent base 22 of the chamber. This sterile
steam or superheated air is supplied at a temperature which is
sufficiently high enough to maintain sterile conditions within the
chamber at all times.
A greater volume of the sterile steam or superheated air atmosphere
is supplied to the sterilization chambers 46 and 88 through the
additional manifolds 30 respectively located therein. The supply of
this additional heated sterile atmosphere to these points maintains
the temperature in these sections at a somewhat higher level than
in the remainder of the chamber 14. This additional heat is
required in order to sterilize the containers and covers
transported through these sections of the chambers. The additional
heat brings the temperature of the containers and covers, which are
supplied thereto in a normally clean condition, to a level
sufficiently high to kill contaminating bacteria on the containers
and covers prior to their being placed on conveyor 18. Of course,
it is also contemplated that the containers and covers may be
supplied to the apparatus in a sterile condition thereby
eliminating the need for sterilization sections 46 and 88.
The sterile food which is supplied through the filling system 82 is
placed in the containers in a sterile atmosphere and any air
entrapped between the food and the covers on strip 92 during the
sealing operation will be sterile, and therefore will not
contaminate the food within the container. The heat seal formed at
the sealing station between the cover and the container is firmly
bonded and made flawless by the cooled platen utilized at the
sealing station so that contamination of the food product within
the container after removal from enclosure 14 is avoided and the
need for re-sterilization of the packed product as required in
previously proposed sterile packaging systems is eliminated.
The sterile atmosphere is supplied from system 20 at a pressure
which is above the atmospheric pressure surrounding the exterior of
enclosure 14. This can be done by suppling the water or air to
system 20 under pressure or by increasing the pressure of the
sterile atmosphere as it leaves coil 24 by the use of pumps as
would occur to those skilled in the art. In either case, this
creates a positive pressure within chamber 14 so that any leakage
of air which may occur in the walls of housing 12 will be outwardly
from chamber 14 so that entrance of contaminating bacteria and the
like into the chamber through any openings therein is avoided. This
is particularly important at the openings in housing 12 at which
the individual containers 48 are supplied to platform 52, at the
opening 90 through which the strip fed covers are supplied at
section 88 and at the discharge opening 164. Thus, because of the
positive pressure within sterile chamber 14, the sterile atmosphere
therein escapes through these openings and prevents surrounding air
from entering the chamber, thereby maintaining sterile conditions
therein. Of course, it is to be understood that these openings are
made as small as possible. In addition, it is noted that vent
openings 170 may be provided at various points in the system in
order to relieve pressure in the sterile chamber 14, so that a
constant flow of newly sterilized air or steam will be continuously
supplied to the chamber.
Accordingly, it is seen that a relatively simple apparatus is
provided for aseptic or sterile packaging of food products or the
like in a single enclosure. The apparatus sterilizes the containers
and covers immediately prior to the filling operation and, in the
preferred embodiment, uses heat sealed covers having no sharp edges
thereon.
Although an illustrative embodiment of the present invention has
been described herein with reference to the accompanying drawing,
it is to be understood that the invention is not limited to that
precise embodiment, and that various changes and modifications may
be effected therein by one skilled in the art without departing
from the scope or spirit of this invention.
* * * * *