Note: Descriptions are shown in the official language in which they were submitted.
CA 02346575 2001-05-08
APPARATUS AND METHOD FOR STRIPPING FILMIC CASINGS FROM
PRODUCTS
FIELD OF THE INVENTION
This invention relates to an apparatus and a method for removing product from
a package having a filmic casing containing the product, and more particularly
to an
apparatus and method for removing such a filmic casing from a food product
held by the
casing in an elongate and generally cylindrical package.
BACKGROUND OF THE INVENTION
The invention will be described with particular reference to packaging bulk
minced
meat in filmic casings for subsequent delivery to a processor who converts the
bulk
minced meat into discrete packages for retail distribution. The present
invention is useful
in opening the casings and separating the casings from the meat so that the
meat can be
converted into the aforementioned discrete packages.
When animals, (notably beef stock) are processed for food, some of the
resulting
meat is minced and packaged in bulk in elongate filmic casings which are
closed at the
ends by various means including metal; clips, heat sealing, etc. These
packages are then
shipped to processors who open the packages manually to strip the filmic
casing away
from the meat. The meat is then further processed into consumer orientated
packages.
The manual process of stripping the casing is both time consuming and subject
to
losses because some of the meat and juices remain in the spent casings.
Further the risk of
contamination is always exacerbated when there is a need for human
intervention in a
process involving food preparation.
Accordingly, it is among the objects of the invention to provide an apparatus
and a
method that limits human intervention when filmic casings are stripped from
packages for
extracting the product from the packages for further processing.
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CA 02346575 2001-05-08
SUMMARY OF THE INVENTION
In one of its aspects, the invention provides an apparatus and a method for
processing packages made up of a filmic casing containing a product, to
separate the
casing from the product for subsequent further processing of the product. The
package is
moved through a series of steps to first weaken the casing, and then a leading
end of the
moving casing is gripped and the end of the casing is moved away from the
product. As a
result the casing is stripped off the product as the weakened casing opens and
the product
continues to move.
BRIEF DESCRIPTION OF THE DRAWINGS.
The invention will be better understood with reference to the accompanying
drawings, in which:
Figure 1 is an isometric view of a package with a portion broken away to
better
show a typical product to be processed by the invention;
Figure 2 is a diagrammatic perspective view of apparatus according to a
preferred embodiment of the invention, and showing stations in the apparatus
that are
used in practicing a preferred embodiment of a method according to the
invention;
Figure 3 is a diagrammatic perspective view of the apparatus with portions in
ghost outline to permit illustration of major components of the apparatus;
Figure 4 is an end view looking from the right of Figure 3, and illustrating a
loader used to feed packages into the apparatus and including background parts
in ghost
outline; and
Figures 5 to 8 are schematic representations of the apparatus in use to remove
the filrnic casings and expose the product for collection and subsequent
processing.
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CA 02346575 2001-05-08
DESCRIPTION OF THE PREFERRED EMBODIMENT(S).
Reference is first made to Figure 1 which illustrates a package 20 of the type
to be
opened by apparatus according to the invention. The package 20 in this example
consists
of a filmic casing 22, which is conveniently tubular, and minced meat product
24 packed
into the casing. The ends of the casing in this exemplary package are secured
by crimped
metal clips 26 which seal the casing to exclude invasion by fluids and
bacteria, and so that
the sealed package 20 can be shipped to a food processor. Here the package 20
is opened
to release the product 24 for further processing into consumer orientated
packages. The
apparatus according to the invention is provided to perform this process.
Reference is now made to Figure 2, which is a somewhat diagrammatic
representation of apparatus according to the invention, and designated
generally by the
numeral 28. The apparatus 28 has stations along an operating path (indicated
generally by
the numeral 29) and which extend along the length of the apparatus. Packages
20 of
processed product (which in this example is minced meat) are stored on a
loader 30 ready
for automatic transfer from the loader 30 into the path 29 where they meet a V-
shaped
conveyor 32 forming part of a transport mechanism which moves the packages
through
the apparatus. This conveyor is made up of two similar belt conveyors 34, 36
inclined
with respect to one another to better support the package 20 in alignment with
the
operating path 29.
The package 20 is moved along the operating path 29 to pass sequentially
through a
cutting station 38 where the filnmic casing 22 (Figure 1) is slit and then
through a stripper
40 where the slit casing is pulled off the product and fed through an exhaust
system 42
having a pipe 44. The casing 22 is driven through the pipe 44 under the
influence of
suction applied to the pipe 44 externally by a conventional vacuum exhaust
system.
At this point the separated product 24 retains its compacted shape and passes
off
the V-shaped conveyor 32 onto a flat belt 46 which carries the product through
a metal
detector 48 to ensure that there is no metal (such as clips off the casing) in
the product.
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CA 02346575 2001-05-08
The product then passes through a chopper 50 which simply breaks the product
down
into more manageable pieces before the product exits through an outlet 52 for
collection
in any convenient way. Of course equipment used in further processing can be
arranged
to receive the product directly from the outlet 52.
The apparatus is constrained to follow a predetermined sequence of steps using
conventional switching and sensing devices controlled electrically from a
controller 54.
Reference is next made to Figure 3 to describe in general terms the operation
of the
loader 30, cutting station 38 and stripper 40. The operation will subsequently
be described
in more detail with reference to Figures 4 to 8. As seen in Figure 3, packages
20 are placed
on the loader 30 in parallel for moving down a ramp 56 under the influence of
gravity to
meet an elevator 58 (better seen in Figure 1). The controller 54 operates to
move
packages one by one to the conveyor 32 with a predetermined space between
packages
sufficient to ensure that the packages are processed individually. The spacing
can be
varied as will be explained with reference to Figure 4.
The V-shaped conveyor 32 is in two parts, 59, 60 with a space 62 between the
parts
sufficient to provide clearance for a transverse cutter 63 which has a
circular cutting blade
64. The blade 64 is driven directly by a motor 66 which is mounted to move
into position
to cut the package 20 and to then to withdraw below the operating path 29
remote from
the package. This action on a package will be described in more detail with
reference to
Figure 5.
After passing the transverse cutter 63, the package will meet a longitudinal
cutter 68
having a cutting blade 69 driven by a motor 71. The longitudinal cutter 68 is
mounted on
a fixed bracket 73 and has an angular adjuster 75 for setting of the effective
height of the
blade 69. This allows the cutter 66 to be set to different heights of package
20 in the
conveyor 32 to ensure that the longitudinal cutting action is completed, as
will be
described.
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The arrangement of cutters 63 and 68 is such that the resulting transverse and
longitudinal slits in the casing meet to form a generally T-shaped slit with
the transverse
slit being near the clip 26 on the leading end of the package 20.
At this point the casing 22 is ready to be stripped off the product. To do
this, a
gripper 70 is lowered into alignment with the package 20 and the gripper
operates to grab
the casing 22 and clip 26 before moving upwardly away from the operating path
29 to drag
the casing 22 off the product 24. Once the gripper has moved above drivers 72,
the
drivers come together to assist in moving the casing 22 upwardly into the pipe
44 of the
exhaust system 42 whereupon the casing 22 is released and allowed to travel
through the
pipe under the influence of the exhaust system 42, and in particular a vacuum
source
applied to the pipe to draw the casing through the pipe 44. The product 24 is
then free of
the casing 22 and continues to travel along the path 29 before leaving the
conveyor 32 and
dropping onto the belt 46 (shown in Figure 3 in ghost outline). The process
will now be
describe in more detail with reference to Figures 4 to 8 to show how the
apparatus
interacts with packages and to better explain the method according too the
invention.
Reference is now made to Figure 4 which shows the loader 30 as seen from the
right end of Figure 2. Packages 20 are stored on the ramp 56 ready to meet the
elevator
58 which handles one package 20 at a time. When the apparatus is ready for
another
package, an actuator 74 is energised to drive an elongate tray 76 about a
pivot 80 which
extends in parallel with the path 29 (Figure 2). The actuator 74 is hinged at
82 to allow
changes in alignment as the tray 76 rotates and elevates a package 20 into
elevated
position, shown in ghost outline. The package is then free to fall into the
conveyor 32.
The tray 76 is shaped so that as it is elevated, a retaining wall 84 comes
into play to restrict
any movement of the next package 20 to thereby retain the packages on the ramp
56.
When the tray 76 returns to the lowered position, shown in full outline, the
next
package 20 will roll onto the tray ready for movement onto the conveyor 32. As
a result,
the packages 20 are delivered one at a time onto the conveyor 32 for movement
into the
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CA 02346575 2001-05-08
cutting station 28 (Figure 2). Also, the packages are spaced along the
constant speed
conveyor 32 by varying the rate of operation of the actuator. Consequently the
spacing
can be increased by slowing the actuator 74 and conversely increased by making
the
actuator move more quickly.
Reference is next made to Figure 5 which is a schematic drawing illustrating
the
passage of the packages along the operating path 29 from the loader 30 to the
cutting
station 38. A leading package 20 is at the downstream end of the first part 59
of the
conveyor 32 and moving along the path 29. The package 20 has met an optical
sensor 86
(also seen in Figure 3) in the cutting station 38 and at the same time, the
package 20 has
met the transverse cutting blade 64 which has created a transverse slit in the
package under
and adjacent to the clip 26. The controller 54 responds to a signal from the
sensor 86 to
cause the cutter 63 to move from a raised or cutting position shown in full
outline, to a
stored position shown in ghost outline. In the latter position the blade 64 is
below the
conveyor 32 and no longer in position to affect the package.
The optical sensor 86 in the cutting station 38 will also sense when the
package 20
has passed the sensor and the resulting signal will cause the controller 54 to
activate the
transverse cutter 63 to return the cutter into the cutting position ready for
the next
package. The time taken to return the cutter 63 to the cutting position is a
factor in the
spacing between the packages as they are driven along the conveyor 32. It will
be evident
that similar considerations will come into play at each step of the process
and that the
spacing is achieved by varying the rate of movement of the tray 76 in the
loader 30 as
previously axpalined with reference to Figure 4..
Figure 5 also shows the action of the longitudinal cutter 66, parts of which
are
shown in Figures 3 and 5. As shown in Figure 3, the blade 69 is about to be
adjusted into
a cutting position (as seen in Figure 5) where it will cut the underside of
the passing
package 20 longitudinally. The action of the longitudinal cutter 68 is such
that a
longitudinal slit is made by the blade 69 to start at the transverse slit and
to extend to the
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CA 02346575 2001-05-08
trailing end of the package. The height of the blade 69 is chosen so that
there is no
possibility that the longitudinal blade 69 will meet the trailing clip 26 on
the package 20 to
ensure that there will be no debris from the clip to contaminate the product.
The length
of the longitudinal slit should be as long as possible to better facilitate
the stripping of the
casing 22 from the product 24 in the stripper 40 as will be explained.
The longitudinal cutting action of the cutter 68 will cause a reactive force
which
tends to lift the package off the blade 69, and this is prevented by the use
of a reaction
roller 88 positioned generally above the blade 69 and free to roll on the
package 20.
The package 20 has now been prepared for the stripper 40 and the controller
has
caused the gripper 70 to move from a raised position shown in Figure 3 to a
stored
position shown in Figure 5 where the gripper 70 is ready to grip an oncoming
package 20.
This is achieved by mounting the gripper on an actuator 90 which moves the
gripper
vertically between the two positions.
The gripper 70 is ready to be activated and will remain in this condition
until the
slit package meets a sensor 92 (seen diagrammatically in Figure 3) and this
combines with
the controller 54 to cause the gripper 70 to grab the leading end of the
package 20
complete with the associated one of the clips 26 before starting an upward
movement as
illustrated in Figure 6. A pair of curved reaction plates 94 (Figure 3)
prevent the packages
lifting as the gripper 70 moves upwardly. These plates can be changed or
adjusted to
match sifferent product shapes and sizes.
Initially the gripper 70 moves upwardly between the plates 94 and then through
a
space between a pair of drive rollers 96, 98 (see also Figure 3) in an open
position. These
rollers are driven by a motor 100 and gears 102 which mesh when rollers 96,98
are
brought together into a closed position. For simplicity, the supporting
structures have
been omitted from the drawings. However it will become evident that the
rollers are
spaced apart in an open position as the gripper 70 passes and then moved into
a closed
position. Then the drive rollers are brought together about the casing and
driven to assist
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CA 02346575 2001-05-08
the gripper to pull the casing upwardly off the product. At the same time the
rollers
squeeze the casing to cause any juices to fall downwardly onto the product and
belt 46,
thereby minimising waste.
Reference is next made to Figures 7 and 8 which show how the spent casing is
transferred from the gripper 70 to the exhaust system 42. As the gripper 70
approaches
the system 42, the gripper 70 releases the casing 22 which is still driven by
the rollers 96,
98. As a result the casing comes under the influence of the vacuum drawn
through the
pipe 44 and is swept away through the pipe 44 as it leaves the rollers.
Once the casing has left the stripper, the rollers open and the gripper is
driven back
into the Figure 5 position ready for another package.
The invention has been described with reference to an exemplary package and
product. Although the invention will have particular utility with such a
package, it is
within the scope of this invention to provide apparatus and method for general
use to strip
filmic casings off product.
Of course there will be limitations due to the process used. For instance the
product must be such that it is not damaged by the cutters in the cutting
station. However
there are variations that will be evident and within the scope of the
invention. For
instance, the casing could be weakened without actually cutting it by forming
lines of
weakness transversely and longitudinally so that the lines of weakness will
break to allow
the casing to be dragged off the product. Slitting is one form of weakening
the casing.
Another possible variation is to use packages that are not cylindrical. This
could
happen because cylindrical packages are shipped in containers where the
packages on the
bottom will be deformed by the weight of the packages above them. A variety of
products
having a range of shapes and sizes can also be accommodated although some
variations to
the loader and other parts will be in order without departing from the scope
of the
invention.
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Yet another possibility is that the operating path may not be horizontal. It
is not
necessary that the path be horizontal as long as the direction of action of
the stripper is
such that the casing leaves the product and the product can be collected.
These and other variations are within the scope of the invention as described
and
claimed.
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