Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
Fleld of the Invention
The invention relates to the packaging industry and more
particularly to fiber cans and to a method and apparatus for
manufacturing them.
The Prior Art
Patents 2,793,126; 2,793,127; 3,144,193 and 3,940,496
- describe fiber cans used in the packaging of food products
such as refrigerated dough which must be removed from the
can through an opening extending from one end of the can to
the other. These cans include a fiber body having a line of
weakness i.e., a separation line which extends the length of
the can through which the dough products can be removed when
the can is opened. The separation line is held shut at least
in part by the label which overlies the separation line.
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In the last mentioned patent a reinforcing tape is also used
to hold the separation line in tact until removed. In all of
these patents a circumferentially extending cut is made through
the label to provide a tab which can be lifted manually for
removing the label in the first stage of opening the can. In
the past, this cut has been produced by rotating the can on
its own axis while forcing a knife against the exterior of the
can body. This operation is illustrated for example in
patent 3,756,128. It will be noticed that the collar cut is
made in the completed tube after the label has been applied.
The collar cutting knife must cut the label completely and
extend slightly into the body wall of the container in order
to make sure that no portion of the label remains unsevered
which could cause the label to rip erratically as it is
removed. The cut in the fiber body beneath the label weakens
the can slightly and it has now been d.iscovered that the can
wall is usually reduced in thickness by about .005 to .008
inches. Thus, for example, a can of .026 inch fiber stock
will be reduced to about .~21 or .018 inches in thickness
along the line where the collar cut is made. Moreover, a~
slight bulge occurs where the cut is made when the dough
filled cans are stored over extended periods of time. This
can rupture the seal in the can liner beneath the collar cut
causing the can to leak. In addition, the edge of the label
adjacent to the collar cut sometimes becomes glued down to
the underlying fiber body wall. Equipment for performing the
collar cutting operation has also been expensive since one
collar cutting unit is required for each of the cans
simultaneously cut from the tube stock.
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Objects
The major objects of the invention are to provide an
improved dough can as well as a method and apparatus for manu-
facturing them wherein a) the can is stronger but includes a
reliable collar cut of the general nature previously employed,
b) provides a can which is less expensive than a corresponding
can having a conventional collar cut, c) provides a fiber
dough can for foods such as dough products with a collar cut
wherein the fiber body stock of the can is not cut, d) has
the ability to open reliably without the label tearing
erratically, e) provision for making a flying cut in the label
stock material in synchronization with the winding of the
can.tube, f) provision for preventing the collar cut from
spiraling which if it occurred could interfere with the reli-
able opening of the can, g) prevention of a condition in which
the cut through the label does not ~enetrate the label
completely or where the edge of the paper label stock adjacent
the collar cut becomes accidentally glued down to the under-
lying body stock material, h) provision for simplifying
production equipment by eliminating several collar cutting
units for each can line and replacing them with a single unit
which cuts all label material.
The Figures
Figure.l is a plan view of an apparatus for forming cans
in accordance with one form of-the invention.
Figure 2 is a side elevational view of the apparatus of
Figure 1 as seen from the side closest to the bottom of the
sheet.
Figure 3 is an end elevational view taken on line 3-3
of Figure 2.
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Figure 4 is a partial transverse sectional view taken on
line 4-4 of Figure 1 on an enlarged scale turned so that the
incoming web 16 is in a horizontal position.
Figure 5 is a diagramatic plan view of the label as it is
cut during the first stage of the cutting operation.
Figure 6 is a view similar to Figure 5 during the sub-
sequent stage of cutting.
Figure 7 is a view of the next stage of cutting.
Figure 8 is a view of a piece of label stock which has
already been cut as it appears after being unwrapped from a
freshly formed tube of stock from which cans are to be cut.
Figure 9 is a side elevational view of a finished can
embodying the invention.
Figure 10 is a view similar to Figure 9 of a modified
form of the invention.
Summary of the Invention
A can is provided for foods such as dough that includes a
tubular can body formed from a body strip having a separation
line extending ~rom one end to the other with a label strip
or-sheet thereover and preferably glued to the body strip on
-either side thereof to prevent the separation line from open-
ing during shipment and storage. The label includes a partial
circumferential collar cut extending across the label material
to define a line along which the label separates allowing a
portion of the label to be removed when one edge is lifted
and pulled back. The collar cut extends from one edge of
the label or near one edge toward the other edge. In one
form of the invention it terminates at a point spaced from
the other edge of the label.
During manufacture, the body strip and label strip are
wound continuously onto an elongated mandrel with the label
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stock over the body stock. The partial collar cuts in the
label are formed by severing the label stock before it is
wound upon the fiber body during the manufacture of the tube
from which the cans are cut. A knife or other label severing
means is used to cut or perforate the label stock either prior
to and separate from tube formation or immediately prior to
wrapping the label onto the can body. The collar cut can
comprise one or more cuts or perforations but does not sever
the label stock completely.
In accordance with one preferred form of the invention
the collar cuts are formed by making a flying cut in the label
stock material. The flying cut is formed by providing a cut-
~ing knife and a means for moving the cutting knife into
contact with the label stock just prior to wrapping the label
stock helically around the freshly ~ormed container tube stock
during for~ation o the tube from which can length pieces are
cut. Thus, as the label is wound onto and bonded to the tube,
the knife is driven rectilinearly ir~ synchronization with the
label material being wound so that a given point on the label
has a velocity component parallel to the axis of the tube
equal to the velocity of the knife blade along the same axis.
The cut is formed only partially through the width of the
label material and terminates short of the opposite edge of
the label SQ that a ligament o uncut label stock is present
to assure that the label will continue to be drawn onto the
tube being formed.
The apparatus comprises a supporting framework, at least
one knife blade or other sheet severing means, means for
moving the knife blade rectilinearly, means for synchronizing
the knife blade movement with the speed of the label stock
and means for controlling the location of the starting point
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at which each cut is made so that each cut can be spaced at a
selected distance from the can end.
In a preferred form of the invention, the cutter is mounted
upon a can forming and winding apparatus of conventional known
construction and is positioned relative to other parts of the
equipment to cut the label just before the label is wound onto
the tube. A plurality of knives are preferably provided. Each
knife is supported upon a roller chain entrained over a pair of
sprockets driven at an appropriate speed and direction to move
the blades as described above along one run of the chain. The
blades in the other run return to the starting point. The chain
can be driven from the can winder preferably through a mechanical
means for advancing or retarding the position of the knives relat-
ive to the position of reference indicating position marks on the
web so that each cut will be made a predetermined distance from
the can end or other mark on the can.
In another form of the invention the partial collar cut com-
prises perforations or cuts arranged end-to-end and in this case
can be provided in the label stock when it is formed, printed or
wound in the coils and need not be done just prior to winding it
onto the can body.
Thus, in accordance with the present teachings, a method is
provided for forming a fiber can which comprises providing an
elongated winding mandrel, continuously winding a strip of fiber
can body materi~l onto the winding mandrel, continuously winding
a strip of label material onto the strip of body stock material
and just prior to applying the label strip to the body stock strip
partially severing the label strip to define a partially collar
cut extending circumferentially of the can being formed, the
collar cut extending from one end thereof in the direction of the
opposite edge and having a termination point spaced from the
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opposite edge wlth a ligament of unsevered label material between
the termination point and the opposite edge.
In accordance with a further embodiment of the present
teachings, an apparatus is provided for forming a collar cut in
a fiber can which comprises a supporting framework, at least one
knife mounted upon the framework and adapted to be positioned to
engage can label stock material just before the label stock mater-
ial is wound into tube form, and drive means provided to move the
knife into contact with the label stock during formation of the
tube, the knife being driven rectilinearly with respect to the
tube and parallel to the axis of the tube being formed, phase
shifting means provided associated with the drive means, sensor
means provided connected to the phase shifting means and opera-
tively associated with the label stock to advance or retard the
phase shiting means responsive to registration marks on the
label stock, whereby the knife is madle to effect a cut in a pre
determined position with respect to the label stock.
DETAILED DESCRIPTION OF THE INVENTION
The finished can and one preferred method employed for
producing the can is best understood by reference to Figures
5-9. As shown in the figures the can indicated generally
by numeral 10 is cylindrical in shape and is formed by
wrapping body stock strip 12 which can be formed for example
from fiberous material such as chipboard or kraft paper
having a cross-section of about 0.010 to 0.026 inches in
thickness. Body stock layer is wrapped continuously onto
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a mandrel 14 in a conventional manner as will be understood
by those skilled in the art using any commercially available
tube winding equipment suitable for this purpose. Since the
tube winder is entirely conventional it will not be described
in further detail.
Over the fiber body stock layer 12 is helically applied
a label strip 16 formed from material lighter than the body
stock such as paper laminated to aluminum foil. The label
has a smooth outer surface to which printed indicia such as
trademarks, opening instructions and cooking directions are
imprinted as seen at 18. Glue is suitably applied to the
label before being bonded in place over the body stock layer
12 in any conventional well known manner. Usually but not
necessarily, a separate liner ply is wrapped inside the body
stock layer 12. For simplicity the liner has not been shown
in the figures. If the liner is desired, any conventional
well known material such as a laminate of paper and aluminum
foil can be used for this purpose.
Where the side edges of the body stock abutt against
one another on the mandrel 14, a line of weakness if formed
in the can which serves as a separation line 20 extending
substantially from one end of the can to the other enabling
the can to be opened along its full length for the removal
of the dough products or other foods contained in the can.
Individual cans are severed from one another along lines
22. That is to say, the tube made up of layers 12 and 16 is
severed in any conventional well known manner, for example,
described in patent 3,756,128 to separate the tube
into can length sections.
The formation of the tube and can body thus far
described is entirely conventional. The formation of the
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collar cut will now be described particularly with reference
to figures 5 through 7. As seen in the figures, a cutting
means such as a knife blade 24 is inserted into the paper web
16 with the blade oriented at right angles to the mandrel 14
and tube wrapped thereover. The blade 2~ is moved as the
wrapping procedure takes place in the direction parallel to
the mandrel 14 and tube with velocity of the velocity com-
ponent of a point on the label 16 in a direction parallel to
the axis of mandrel 14 and the tube thereon. In this way a
partial collar cut 26 is formed in the paper label stock 16
prior to application of the paper label stock to the tube 12.
In other words, the flying cut is made in the paper strip 16
at a point spaced from the tube so that the cut is present at
the time the label is wrapped onto the tube. The partial
collar cut extends circumferentially of the tube after
completion and is oriented substanl:ially at right angles to
the axis of the mandrel end of the tube. It is to be under-
stood that as the cut is being made, the knife must travel
in t~e same direction with the same velocity component as
the label has at right angles to the cut in label 16 in order
for the paper from which the label is made not to be torn.
It will be noticed that the cut 26 extends all the way to one
- edge of the label to form an acute angle of about 60, defin-
ing a lifting tab T to be lifted when the label is removed
in the process of opening the can. The other end of the cut
26 terminates at 28 short of the opposite edge of the sheet
16 to define a ligament 30 of uncut paper between the end 28
of the cut 26 and the opposite edge of the label stock. This
ligament assures that the label stock can be wound continu-
ously onto the body stock layer 12. The length of ligament
30 is not critical but is preferably less than 2 to 3 inches
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in length. Excellent results have been achieved when it is
about 1/4 inch long. It can be shorter if the label does not
tear during winding. The ligament can be longer if a tear
member such as a ribbon or string is adhered to the label and
extends from tab T parallel to the collar cut around the
entire can.
After the tube is completed and severed along lines 22,
the resulting tubular can body sections are capped with suit-
able end closures such as steel discs 32 and 34 that are
crimpled or otherwise affixed to the top and bottom ends of
the can. The can body tube is sometimes sold by the manu-
facturer without either end applied but is more usually sold
with the top closure 32 attached. The bottom end closure 34
is applied by the can user after the contents have been
introduced.
It will be seen in accordance with the present invention
that the collar cut 26 by being formed prior to wrappiny the
label stock material 16 onto the can body, eliminates the
need for forming a collar cut after the can is complete and
accordingly there is no opportunity for the fiber body stock
layer 12 to be cut beneath the coIlar cut 26. Thus, the
chances for the can to be weakened by this manner is elim- ;
inated. When the can 10 is to be opened, the tab T is lifted
and the label portion below the collar cut 26 is removed.
If removed entirely, the ligament 30 of uncut label material
is torn manually in the removal operation. This exposes the
underlying line of weakness 20 which is then opened either
by striking the can against a solid object or allowing the
pressure of the material in the can to separate che can on
line 20 thereby allowing the contents oE the can to be
removed through an opening which extends from substantially
one end of the can to the other.
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Refer now to Figure 10 in which the partial collar cut
26 has been replaced by a partial collar cut 26a composed of a
plurality of short unconnected perforations or cuts 26b each
positioned end-to-end and each oriented at an angle to the can
end 22. The partial collar cut 26 extends circumferentially
of the can. When tab T is pulled, the material between the
cuts 26b tears allowing the label to be removed. The cuts
26b are formed in the strip 16 by any suitable well known
strip perforator synchronized with the label printer. They
can also be formed at any other convenient time e.g., when
the strip 16 is cut from a roll or is rewound and need not
be formed just before winding into tube form. Thus a conven-
tional perforator can replace the apparatus of Figures 1 - 4.
The partial collar cut 26a of Figure 10 does not, however,
allow removal of the label as reliably as Figures 5 to 9.
Refer now to Figures 1 to 4 which illustrates one pre-
ferred form of apparatus used for forming the collar cut in
accordance with the invention.
As seen in the Figures, the apparatus includes a support~
ing framework made up of a supporting post 40 having a
circular mounting flange 42 at its upper end to which is
secured a horizontal supporting frame member such as a metal
bar 44 having mounting brackets 46 and 48 at the opposite
ends thereof to which are secured coaxial pillow blocks 50
and 52 respectively attached to the free ends of mounting
plates 50a and 52a the latter being adjustable horizontally
by means of horizontal adjustment bolt 54 and 56 respectively
and locked in place by means of horizontal locking bolts 58
and 60 respectively. Vertical adjustment of the brackets
and pillow blocks 50 and 52 is accomplished by means of
vertical adjustment bolts 62 and 64 each locked by a vertical
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locking bolt 59 (only one of which is shown in Figure 3) so
that the cutting head to be described below can be precisely
adjusted both vertically and horizontally to bring it into
parallel alignment with -the winding mandrel 1~. Bolts 50a
and 50b hold the b~locks on the plates.
Positioned horizontally and journaled for rotation
within the pillow blocks 50 and 52 is a drive shaft 66 which
is powered via chain and sprocket assembly 68 that is driven
from a phase shifting differential 70 which is in turn driven
by a chain and sprocket assembly 72 secured to a drive shaft
74 that is connected to or itself comprises the power shaft
from the can tube winding apparatus and thereby turns at the
same speed and direction as the tube winder. Thus, as the
tube winding drive speeds up or slows down, the drive shaft
74 and shaft 66 changes speed correspondingly and the cutting
means moves at a speed proportional to the speed at which the
body and label layers are wound. The relative position of
sha~t 66 can be advanced or retarded with respect to shaft 74
by the phase shifting differential which is most conveniently
; 20 operated by a correction motor M that is controlled.either
manually or automatically, for example, by means of a photo
eye 76 positioned adjacent the edge of the label 16 and
adapted to sense position indicating reference marks 78
printed on the label. The correction motor will advance the
differential 70 and shaft 66 in the event the shaft 66
driving the cutter is too late with reference to the marks
78 or retard the shaft 66 in case it is ahead of the marks
78 to thereby position each collar cut 25 at the proper
location with respect to the end of the can 22 as indicated
by the printing on the label strip 16 and register marks 7$.
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Mounted upon the shaft 6~ are four bearings B, two of
which support a housing 80 and two of which support a housing
83. Splined to shaft 66 by a key K and slidable thereon within
housing 80 ~s a ~elicoid gear 82 which drives a knife sprocket
assembly 84 through a mating gear 88 and sprocket shaft 86.
Shaft 86 is supported in housing 80 upon bearings 87 and g9
and has its free end fastened to a chain sprocket 90 over which
is entrained one end of chain 92. The other end of chain 92
is entrained over a sprocket 94 mounted rigidly upon a shaft
96 which is journaled for rotation in housing ~3 in all respects
similar to that of shaft 86 except that is is no~ driven, no
drive gears being present. A friction drum 98 is connected to
the opposite end of shaft 96. Engaged over drum 98 is a
looped leather belt 100 the ends o~ which are connected
together by means of a bolt and nut assembly 102 and fastened
to a spring 104 whi¢h is connected to housing 80 for exerting
a constant frictional drag on the ~3haft 96 to keep the lower
run of chain 92-ti~h~t at all~-times.
Mounted on the chain 92 at uniformly spaced apart
intervals equal to the length of one can 10 are a plurality
of collar cutting knives 1~6 each supported upon a bracket
108 secured to the chain. ~ach bracket is provided with a
horizontal extension 110 that projects laterally on both
sides into grooves within horizontally extending parallel
tracks 112 to thereby precisely position the blades or knives
as thè knives travel horizontally parallel to the mandrel 14
in the operating dotted line cutting position designated 113
of figure 3 which shows the cutting head as seen in end
elevation. The cutting assembly and ~nives 106 are mounted
within a housing 114 which is secured by bolts or other
fasteners to a horizontal mounting bar 116. The housing
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114 includes a cover ll~a formed from transparent material
such as plexiglass and is held in place by a metal brace arm
114b and retaining bolts 114c. Chain slack is taken up by a
bolt 130 which projects through a flange 131 rigidly secured
to and extending downwardly from bar 116 such that the end of
bolt 130 strikes the right side of the housing 80 as seen in
Figure 1. After the chain tension is properly set, four
bolts 132 are securely tightened to lock the housing 80 in
place with re-spect to the bar 116~ During operation, the bar
116 housings 80 and 83 and the housing 114 can be moved to
the left or right on shaft 66 by means of a traverse con- ~ :
necting rod 134 which is itself coupled to a servo 136
controlled by means of a sensor 138 that detects the position
of the edge of the label 16 and thxough the servo moves the
rod 134 and the entire cutting assembly 84 to the left or
right as seen in Figure 1 followin~ the edge of the label to
thereby compensate for any waivering to the left or ri~ht
o~ the label a6.~
A pair of web hold down arms 150 and 152 are provided
: 20 on bar 44 to support the ends of the hold down bar 154 best
seen in figure 2 and figure 3. ~ castered wheel 160 is
mounted upon a suitable bracket 162 connected to the bar 116.
Wheel 160 is pivoted at 164 with its center offset from the
axis 165 of its own pivot pin 166 so ~hat it will fol;low the
contour and align itself with the edge of label 16 as the
tube is being wound. ~he wheel 160 i~ positioned in
alignment over the edge of the label 16 to thereb~ press the
edges of label 16 against the underlying fiber body stock
material 12 where glue is applied to thereby secur~l~ bond
the label to the body stock.
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rrhe bar 116 also has secured to it by means of a
supporting bar 170 a castered wheel 172 mounted for pivotal
movement upon a pivot pin 174. It rests upon the winding
mandrel 14 and supports the cutting assembly when the machine
is in operation. The distance that wheel 172 extends from
the cutting head can be changed by penetration control adjust-
ment nuts 176 - 178 to thereby accurately control the depth
of penetration of knife 106 through the label material 116
while the cutting head is in the dotted line position 113 of
figure 3.
When knives 106 are to be changed, the cutting head 84
is convenientl~ moved to a vertical position shown b~ dotted
lines at 188 in figure 3.
A safety back up bar 190 is mounted upon the frame
member 44 to help reduce dama~e due to blow ups (an occasional
uncontrolled flying apart o:E the coils wound on the mandrel).
During operation, the drive shaft 74 from the tube
winder imparts motion via chain and sprocket assembly 68 and
72 and phase shifting di~ferential 70 to drive shaft 66.
The phase being controlled by registration sensor 76 operat-
ing through the correction motor M which periodically either
advances or retards the position of the shaft 66 with
relationship to shaft 74 to keep the knives 106 cutting at the
right place with respect to the location of the repeated
printin~ pattern on the label stock 16. The rotation of
shaft 66 drives the chain sprocket 90 and thè chain 92
through the gears 82 and 88 at the proper speed to move the
lower run of the chain 92 and the knives 106 in the same
direction and with the same component of velocit~ in a
~: 30 direction parallel to the axis of the tube and label 16.
When the cutting head is in position 113 each one of the
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knives 106 will in succession produce a collar cut in the label
16 as shown and described above in connection with figures 1
through 5. Each slit terminates short of the opposite edge of
the label material at 2B to provide an uncut ligament 30. The
uncut ligament can be any length but is preferably not over
2 to 3 inches. Excellent results have been obtained with the
ligament 30 about 3/4 inches in length.
It can also be seen that frame member 116, the housings
80 and 82 and the cutting assembly 84 are pivotable as a
unit about the center of the drive shaft 66 and the cutting
depth control wheel 172 mounted upon the cutting assembly 84
engages the surface of the tube being wound during operation
to support the cutting assembly~ The nuts 176 and 178 act
as selectively adjustable means for moving the cutting depth
control wheel 172 upon the cutting assembly either toward or
away from the mandrel 14. In this way, the engagement between
the cutting depth control wheel ancl the tube determines the
cutting depth of the kni~es 106.
The take up of bolt 130 allows adjustment of the chain
92 to a large range of center distances as required for cans
of diferent lengths. Thus, for each new can length, a
change in the knife spacing will be necessary. A11 that is
necessary is to install a new chain with a different knife
spacing, adjust bolt 130 to the proper chain tension and
tighten the bolts 132.
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