Note: Descriptions are shown in the official language in which they were submitted.
1 207 58 04
SERVO MOTOR OPERATED INDEXING MOTION
PACKAGING MACHINE AND METHOD
BACKGROUND AND SUMMARY
This invention relates to an indexing motion
machine and method for producing discrete packages of
articles, such as vacuum packaged food products or the
like. More particularly, the invention is directed
to a cross-cut assembly for use in an indexing motion
packaging machine.
To produce discrete individual packages of food
products such as frankfurters, sliced luncheon meat, cheese
or the like, it has been known to employ packaging machines
providing either continuous motion or indexing motion.
Continuous motion machines typically provide a higher rate
of package production than indexing machines. However,
indexing machines have been in existence for a long time,
and their design is well refined. Accordingly, indexing
machines are reliable in operation.
The present invention has as its object to pro-
vide an indexing motion package forming machine which is
capable of producing packages at a rate equivalent to or
greater than the rate at which packages can be produced on
a continuous type machine. A further object of the inven-
tion is to provide an indexing motion package forming
machine utilizing motors with programmable controls to
control the movement of the various components of the
package forming machine, to provide accurate positioning of
the machine components and to provide variability in the
package dimensions to accommodate packaging of different
products.
In accordance with one aspect of the invention, a
packaging machine includes a forming station in which a
flexible web of packaging material is deformed so as to
provide a cavity adapted to receive the product to be
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packaged. Forming tooling defines the forming cavity, and
the tooling is movable between a first position in which it
engages the web of packaging material and acts on the web
to form the web into the forming cavity, and a second
position in which the tooling is moved away from web. The
forming tooling is moved between its first and second
positions by a motor having a rotatable output shaft and
including a programmable controller associated therewith.
A lifting and lowering system is preferably interposed
between the forming tooling and the motor output shaft
for moving the forming tooling between its first and
second positions in response to rotation of the motor
output shaft. In a preferred embodiment, the lifting
and lowering system includes a cam-type arrangement in
which strupture defining a cam slot is mounted to the
forming tooling, and a-n arm is mounted to and rotatable
with a rotatable member which is driven through a timing
belt or the like in response to rotation of the motor
output shaft. A roller member is iriounted.to the arm and
is engaged within the cam slot, and alternating
clockwise/counterclockwise rotation of the rotatable
member causes back and forth movement. of the roller
within the cam slot to lift and lower the forming tooling.
This aspect of the invention further-contemplates
a method of forming a product cavity in a flexible web of
packaging material, substantially in accordance with the
foregoing summary.
In accordance with another aspect of the inven-
tion, a packaging machine includes an indexing mechanism
for supplying a flexible web of packaging material to the
forming station of the packaging machine. A movable ad-
vancement mechanism is provided for gripping the flexible
web, and preferably comprises a pair of spaced chains.
Each chain is areferably provided with a series of grippes
members along its length, which grip the edges o~ the web.
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A motor having a rotatable output shaft and having a pro-
grammable controller associated therewith, is drivingly
engaged with the pair of chains. Intermittent operation of
the motor provides indexing advancement of the web to the
forming station. The forming station includes forming
tooling for deforming the flexible web to form a cavity
adapted to receive product to be packaged.
The invention further contemplates a method of
indexingly advancing a web of packaging material in a
packaging apparatus, substantially in accordance with the
foregoing summary.
In accordance with yet another aspect of the
invention, a packaging machine includes a forming station
in which a flexible web of packaging material is supplied
to the forming station. A forming box is located at the
forming station and includes an internal forming cavity.
The forming box is movable to a forming position in which
the web is located over the forming cavity. A vacuum
mechanism provides negative air pressure to the forming
cavity of the forming box when the forming box is in its
forming position. A plug assist mechanism assists the web
to conform to the contour of the forming cavity when the
forming box is in its forming position. The plug assist
mechanism comprises a plug member reciprocably movable
between an operative position in which it engages the web
and moves the web within the cavity to assist the web to
conform to the cavity, and an inoperative position in which
the plug member is withdrawn from the cavity. A motor
having a rotatable output shaft and a programmable control-
ler associated therewith is provided for reciprocably
moving the plug member between its operative and inopera-
tive positions in response to operation of the motor. In a
preferred embodiment, the plug member is mounted to a frame
assembly, and the plug member is reciprocably movable
between its operative and inoperative positions by lowering
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and raising the frame assembly in response to rotation of
the motor output shaft, for moving the plug member between
its operative and inoperative positions. In a particularly
preferred embodiment, the frame assembly is lowered and
raised by means of a linear actuator connected between the
motor output shaft and the frame assembly for lowering and
raising the frame assembly in response to alternating
clockwise/counterclockwise rotation of the motor output
shaft .
This aspect of the invention further contemplates
a method of assisting a flexible web of packaging material
to conform to a forming cavity, substantially in accordance
with the foregoing summary.
In accordance with yet another aspect of the
invention, a packaging machine and method incorporates
forming tooling, an indexing web drive, and a plug assist
mechanism, each of which is independently driven by one or
more motors having programmable controllers, so as to allow
each component to be independently programmed and con-
trolled. This provides variability in the type of package
which can be formed by the machine, as well as providing
accurate control and adjustment of the various packaging
components.
In each of the above-noted aspects of the inven-
tion, the motor preferably comprises a programmable servo
motor.
In accordance with yet another aspect of the
invention, a cross-cut assembly is provided for transverse-
ly severing the webs after the webs are sealed together
about the product. The cross-cut assembly consists of a
frame member mounted to the packaging machine for movement
between a raised position and a lowered position. The
frame member extends transversely across the packaging
machine, and is mounted at one end for pivoting movement.
An extendable and retractable cylinder assembly is inter-
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posed between the other end of the frame member and the
packaging machine, such that movement of the cylinder rod
to its retracted position moves the frame member to its
lowered position, and extension of the cylinder rod moves
t:he frame member to its raised position. A traversing
knife assembly is mounted to the frame member. The knife
assembly consists of carriage having a pair of knife hold-
ers, with the carriage being mounted to the movable output
member of a rodless cylinder. The knife holders are adapt-
ed to receive conventional utility knife blades, and pro-
vide blade replacement without the need for employing tools
to remove an existing blade and to mount a replacement
blade. Each knife holder includes a slot having a width
only slightly greater than that of the blade, to accommo-
date placement of the blade therein. A magnetic retainer
assembly is mounted to each holder, and includes one or
more magnetic elements which maintain the blade within the
slot. A utility knife blade typically includes a pair of
notches along the non-sharpened edge of the blade, and each
knife holder is provided with an upstanding peg which is
adapted to be received within one of the notches, to pro-
vide proper depth location of the blade when mounted to the
blade holder.
Various other features, objects and advantages of
the invention will become apparent from consideration of
the following description taken together with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings illustrate the best mode presently
contemplated of carrying out the invention.
In the drawings:
Fig. 1 is an isometric view of a packaging ma-
chine constructed according to the invention;
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Fig. 2 is a side elevation view of the packaging
machine of Fig. 1, with guards and covers removed to expose
the components of the machine;
Fig. 3 is a schematic side view showing the web
unwinding mechanism for supplying the lower web of pack-
aging material;
Fig. 4 is a schematic view showing the steps
involved in deforming the flexible web of packaging materi-
al at the forming station to provide a product cavity
adapted to receive product to be packaged;
Fig. 5 is an enlarged partial side view showing
the forming tooling in its raised position;
Fig. 6 is a partial transverse sectional view
illustrating the plug assist mechanism of the invention;
Fig. 7 is a partial transverse sectional view
showing a cutting assembly for transversely cutting the
formed packages;
Fig. 8 is a schematic block diagram of control
screen selections for controlling operation of the pack
aging machine;
Fig. 9 is a schematic block diagram of the con-
trol and drive arrangement for the servo motors;
Fig. 10 is a partial side elevation view of the
downstream portion of the packaging machine of Fig. l;
Fig. 11 is a partial transverse section taken
generally along line 11-11 of Fig. 10, showing the cross-
cut assembly;
Fig. 12 is an enlarged partial elevation view of
a blade holder associated with the cross-cut assembly of
Fig. 11;
Fig. 13 is a partial top plan view of the cross-
cut assembly shown in Fig. 11; and
Fig. 14 is a partial section view taken generally
along line 14-14 of Fig. 13.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Figs. 1 and 2 illustrate a packaging machine 10
constructed according to the invention. Packaging machine
generally includes a lower web supply station 12 for
5 supplying a lower web 14 of flexible packaging material
from a supply roll 16, a forming station 18, a loading
station 20, an upper web supply station 22 for supplying an
upper web of flexible packaging material from a supply roll
24, and a downstream station shown generally at 26. The
10 operations performed at downstream station 26 will later be
explained.
The various components of packaging machine 10
are mounted to and supported by a frame assembly (Fig. 2)
including a pair of spaced parallel upper frame members 28,
lower spaced frame members such as shown at 30, 32, and 34,
and a series of vertical frame members extending between
upper frame member 28 and lower frame members 30, 32 and
34. A series of legs 36 are provided for supporting ma-
chine 10 above a floor 38.
Lower web supply station 12 includes a roll
support bracket 90 and an unwind shaft 42 extending from
bracket 40. Supply roll 16 is rotatably mounted to shaft
42, which is stationarily mounted to bracket 40. An unwind
motor 44 (Fig. 2) is mounted to a plate 46, and has its
output shaft engaged with a gear box 48 which includes a
horizontally oriented output shaft driven in response to
rotation of the output shaft of motor 49. A pair of timing
pulleys 50, 52 are fixed to a pair of shafts 59, 56, re-
spectively, which extend through plate 46 and are fixed to
a pair of driven steel rollers 58, 60 (Fig. 3). A timing
belt 62 is trained around timing pulleys 50, 52 and a
timing pulley (not shown) engaged with the horizontal
output shaft of gear box 98.
Referring to Fig. 3, a rubber surfaced nip roller
64 rests on top of driven rollers 58 and 60, forming a pair
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of nips between roller 64 and rollers 58, 60. Lower web 14
is fed below driven roller 58, up and over nip roller 69,
and below driven roller 60. Upon operation of motor 44,
drive rollers 58 and 60 are driven in response to rotation
of timing pulleys 50, 52, and lower web 14 is unwound from
supply roll 16 by rotation of driven rollers 58, 60 and nip
roller 64.
Motor 44 is a conventional variable speed DC
motor, which provides variable speed unwinding of lower web
14 from supply roll 16 during its operation.
From driven roller 60, lower web 14 is trained
around a dancer roller 66 rotatably mounted to a dancer arm
68, which is pivotably supported at its upper end on a
shaft 70 extending between the sides of the machine frame.
As noted previously, and as will be explained in greater
detail, web 14 is advanced through machine 10 in an index-
ing fashion. The dancer assembly, consisting of dancer arm
68 and dancer roller 66, acts as an actuator for switching
unwind motor 44 on and off and for controlling its speed of
operation, for providing unwinding of lower web 14 from
supply roll 16 in response to indexing movement of lower
web 14 through the stations downstream of the dancer assem-
bly.
As noted previously, unwind motor 44 is a vari-
able speed motor. Motor 49 is responsive to the position
of dancer arm 68 which increases or decreases the motor
speed as required to accommodate the indexing advancement
of lower web 14 downstream of the dancer assembly. Motor
44 is normally off, and the dancer assembly selectively
actuates motor 44 and controls its speed of operation.
Referring to Figs. 2 and 3, transducer-type
proximity switch 74 is mounted to plate 96, and is inter-
connected with unwind motor 94 through a motor drive 75. A
cam-shaped switch actuator member 76 is mounted to dancer
arm 68, for selectively actuating proximity
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7?VO 92/10405 - 9- ~ O ~ ~ ~ ~ ~ PCT/US91/09279
switch 74.
Actuator member 76 provides a cam-shaped actuator
surface, which acts on proximity switch 74 to control the
speed of operation of motor 44. As noted previously, motor
44 is normally off. The cam shape of actuator member 76
provides gradual switching of motor 44 between its "on" and
"off" modes.
When lower web 14 is pulled by the indexing drive
mechanism, as will be explained, dancer arm 68 pivots
counter-clockwise so as to bring actuator member 76 into
proximity with switch 74. Proximity switch 79 then causes
motor 44 to operate, first at a low speed and then at a
higher speed as dancer arm 68 further pivots counterclock-
wise, until motor 44 is operating at full speed, to unwind
lower web 14 from supply roll 16. As the supply of lower
web 14 from supply roll 16 catches up with the indexing
advancement of lower web 14, dancer arm 68 pivots about
shaft 70 in a clockwise direction. Actuator member 76 then
causes proximity switch 74 to slow the speed of operation
of motor 44. When the indexing advancement of lower web 14
ceases, motor 44 continues to supply lower web 14 to dancer
roller 66 and dancer arm 68 is pivoted clockwise until
actuator member 76 is moved an amount sufficient to cut off
power to motor 44 through proximity switch 74.
Dancer arm 68 thus moves in an arcuate back and
forth manner as long as actuator member 76 is maintained in
proximity to proximity switch 74 during indexing advance-
ment of web 14 downstream of the dancer assembly continues.
To advance lower web 14, a servo motor 78 is
mounted to lower frame members 34, and includes an output
shaft to which a timing pulley 80 is mounted. A timing
belt 82 is trained around timing pulley 80, and also around
a driven timing pulley 84 mounted to a driven shaft 86.
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Driven shaft 86 is rotatably supported between the sides of
the frame of packaging machine 10.
Referring briefly to Figs. 6 and 7, a pair of
gripper chains shown generally at 88a and 88b, are provided
on either side of the frame of packaging machine 10.
Gripper chains 88a and 88b provide upper runs 90a and 90b,
respectively, and lower runs 92a and 92b, respectively.
The upper and lower runs of chains 88a, 88b are mounted in
inwardly facing slots formed in facing blocks 94a, 94b,
located on either side of the frame of packaging machine
10. Blocks 94a, 94b are mounted to upper frame members 28,
and provide sliding movement of gripper chains 88a, 88b
along the length of packaging machine 10. Blocks 94a, 94b
are formed of an ultra-high molecular weight polyethylene
material.
tripper chains 88a, 88b may be such as manufac-
tured by Curwood, Inc. of Oshkosh, Wisconsin under its U.S.
Pat. No. 4,915,283. This arrangement provides gripping of
lower web 14 along its edges at upper runs 90a, 90b, of
gripper chains 88a, 88b.
Driven shaft 86 (Fig. 2), which is rotatable in
response to rotation of the output shaft of indexing drive
servo motor 78, has a pair of chain drive sprockets (not
shown) connected thereto for engagement with gripper chains
88a, 88b. In this manner, intermittent operation of servo
motor 78 provides indexing movement of gripper chains 88a,
88b, to indexingly advance lower web 14 through packaging
machine 10.
Lower web 14 is gripped between upper runs 90a,
90b of gripper chains 88a, 88b downstream of the dancer
assembly and upstream of forming station 18, and is there-
after supplied to forming station 18 in an indexing fash-
ion.
A web heater apparatus, shown generally at 96, is
located immediately upstream of forming station 18 for
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heating lower web 14 prior to forming of web 14 at forming
station 18. The preheating of web 14 imparts increased
flexibility to web 14 to assist in deforming web 14 at
forming station 18.
Forming tooling is provided at forming station 18
below web 14. As shown in Fig. 2, the forming tooling
comprises a chilled forming box 98 mounted to a frame
assembly 100. As will be explained, forming box 98 is
movable between a raised position and a lowered position.
In its raised position, forming box 98 acts on lower web 14
to deform web 14 downwardly to form a product cavity, and
in its lowered position is moved away from web 14 so as to
allow advancement of web 14 with the product cavity formed
therein.
Fig. 4 illustrates the series of steps which take
place at forming station 18 in order to form a product
cavity 102 in lower web 14. The forming arrangement shown
in Fig. 4 is preferably employed when forming a relatively
shallow product cavity 102 in lower web 19. At position A,
forming box 98 is in its lowered position, and an unde-
formed portion of web 14 is located over the open upper end
of forming box 98. While web 14 is maintained stationary,
forming box 98 is moved upwardly to position B, where the
upper ends of the side walls of forming box 98 come into
contact with the underside of web 19. Negative air pres-
sure is then supplied to the interior of forming box 98
through a vacuum line 104 and a series of air passages
formed in the bottom of forming box 98. At position C, a
plug member 106 associated with a plug assist mechanism 108
moves downwardly under the influence of air pressure so as
to come into contact with the upper surface of lower web
14, and to assist web 14 in deforming into the interior of
forming box 98. At position D, plug member 106 is retract-
ed to its upper position, and the negative air pressure
supplied by vacuum line 104 deforms lower web 14 downwardly
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into the interior of forming box 98 until the lower surface
of web 14 is disposed against the bottom and sides of the
interior of forming box 98. Product cavity 102 is thus
formed. At position E, forming box 98 is moved downwardly
an amount sufficient to allow formed web 14 to advance
downstream from forming station 18, whereafter the de-
scribed sequence of steps is repeated to again form another
product cavity 102 in the upstream portion of lower web 14.
The previously formed product cavity 102 is advanced to
loading station 20, where product to be packaged is placed
into product cavity 102.
Referring to Fig. 2, a servo lift motor 110 is
mounted to lower frame members 30, and includes an output
shaft 112 to which a drive timing pulley 114 is mounted. A
timing belt 116 is trained around drive pulley 114 and a
large driven pulley 118, which is mounted to a shaft 120
rotatably mounted between lower frame members 30. A small-
er diameter lift pulley 124a is connected to shaft 120 on
the inside surface of large timing pulley 118, and a timing
belt 122 is trained around inside-mounted pulley 124a and
around a second lift pulley 124b. Pulley 124b is keyed to
a shaft 126, which is rotatably mounted to lower frame
members 30. With this arrangement, the pair of lift pul-
leys 124a and 124b are rotatable in response to operation
of servo motor 110.
A pair of lift arms 128a and 128b are mounted to
lift pulleys 124a and 124b. Lift arms 128a and 128b are
fixed at their lower ends to shafts 120, 126, respectively,
and therefore are pivotable with shafts 120, 126 in re-
sponse to operation of lift servo motor 110.
As shown in Fig. 5, lift arm 128a is provided
with an inwardly extending upper shaft 130 to which is
mounted a roller member 132. Roller member 132 is mounted
within a cam slot 134 formed in a cam member 136 which is
connected to the underside of frame assembly 100. With
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this arrangement, upon reciprocating clockwise and counter-
clockwise movement of shaft 120 resulting from reciprocat-
ing operation of lift servo motor 110, roller member 130 is
caused to move back and forth in cam slot 134 to raise and
lower frame assembly 100, to which forming box 98 is mount-
ed. Referring to Fig. 2, a cam member 138 is mounted to
the rear portion of frame assembly 100, and includes a cam
slot similar to slot 134 formed in forward cam member 136.
Rear lifting arm 128b is provided with a roller arrangement
similar to that described with respect to arm 128a. Timing
belt 122 trained around lift pulleys 124 provides simulta-
neous lifting and lowering of lift arms 128a and 128b to
raise and lower frame assembly 100. To ensure that lift
arms 128a and 128b remain parallel to each other, a mechan-
ical link (not shown) is connected between arms 128a and
128b.
In a preferred arrangement, a pair of forward cam
members are mounted one on either side of the forward
portion of frame 100, and a pair of forward lift arms 128a
are connected to shaft 120. Similarly, a pair of cam
members 138 are mounted one on either side of the rear
portion of frame 100, and a pair of lift arms 128b are
mounted to shaft 126.
As shown in Fig. 2, plastic bearing block 140 is
mounted to the side of frame assembly 100, and a similar
block is mounted to the opposite side of frame assembly
100. Bearing block 140 entraps the sides of a vertical
shaft mounted to the inside of vertical frame member 144,
and a similar arrangement is provided on a vertical frame
member on the other side of machine 10. The bearing
blocks, such as 140, provide vertical tracking of frame
assembly 100 during lifting and lowering of lift arms 128a,
128b.
Referring to Fig. 5, forming box 98 is mounted to
frame assembly 100 by means of a pair of side plates locat-
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ed on either side of forming box 98, with one of the side
plates being shown at 146. By loosening the side plates,
forming box 98 can be moved to varying positions along the
length of frame assembly 100, and thereafter fixed in a
desired position by retightening the side plates. This
provides accurate positioning of forming box 98 on frame
assembly 100. In addition, forming box 98 can be complete-
ly removed from frame assembly 100 and replaced with a
different forming box providing a different configuration
to the product cavity, to accommodate variations in the
type of product being packaged. The mounting arrangement
as shown and described may be replaced with any other
satisfactory arrangement which provides adjustment and
removal of forming box 98 relative to frame assembly 100.
As shown in Fig. 2, a vacuum junction 148 is
mounted to the frame of machine 10 for transferring nega-
tive air pressure from a vacuum tube 150 to the interior of
forming box 98 through vacuum line 104 (not shown in Fig.
2), in accordance with known principles.
Fig. 2 generally illustrates the location of plug
assist mechanism 108 at forming station 18. Fig. 6 illus-
trates plug assist mechanism 108 in greater detail. The
arrangement of plug assist mechanism 108 shown in Fig. 6 is
employed when forming a relatively deep product cavity in
lower web 14, in contrast to the arrangement shown in Fig.
4. Referring to Fig. 6, plug assist mechanism 108 includes
a frame assembly consisting of front and rear frame mem-
bers, one of which is shown at 152. A pair of side plate
members 154, 156 extend between the front and rear frame
members. A pair of lugs 158, 160 are mounted to side frame
members 154, 156, respectively.
A pair of linear actuator assemblies 162, 164 are
provided one on either side of the frame of machine 10 and
are mounted to the structural members of the frame. Actua-
for assembly 162 includes a,linearly movable output member
r
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_15_
166 which is vertically movable relative to an actuator
body 168. A servo motor 170 is mounted to actuator body
168, for providing rotary input power to actuator body 168
and to provide selective up-down movement of output member
166. Output member 166 is connected to plug assist frame
lug 158.
Linear actuator assembly 164 is similarly con-
structed, providing a vertically movable output member 172,
a linear actuator body 174 and a servo motor 176. Output
member 172 is connected to frame lug 160.
Linear actuator assemblies 162, 164 are prefer-
ably those such as manufactured under U.S. Pat. No.
4, 137, 784.
With the described arrangement, operation of
servo motors 170, 176 results in rotary input power being
provided to linear actuator bodies 168, 174, to provide
vertical movement of linear actuator output members 166,
172, and thereby lifting and lower of the plug assist frame
assembly relative to the frame of packaging machine 10.
An upper plate 178 extends between the front and
rear frame members of the plug assist assembly. In the
illustrated embodiment, forming box 98 provides a pair of
internal cavities to form lower web 14 so as to provide a
pair of side-by-side product cavities. A pair of plug
assist members, shown generally at 180, 182, are mounted to
the underside of upper plate 178 for assisting lower web 14
in conforming to the contour of the internal cavities
provided by forming box 98. Plug assist member 180 in-
cludes a vertical post 184 and a lower forming member 186
connected to the lower end of post 184. Similarly, plug
assist member 182 includes a vertical post 188 connected to
the underside of upper plate 178, and a forming member 190
mounted to the lower end of post 188.
Forming members 186, 190 are dimensioned so as to
fit within the internal cavity provided in forming box 98
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with which each is aligned. Preferably, each edge of
forming members 186, 190 is located approximately 1/2 inch
inwardly from the side wall of the cavity to which it is
adjacent. Forming members 186, 190 are preferably moved
downwardly within the respective forming cavities to a
lowermost position in which the bottom of each of forming
members 186, 190 is at approximately three quarters of the
depth of the cavity.
A pair of vertical guide posts 192, 194 are
mounted to the frame of packaging machine 10. Post 192 is
received within an opening 193 defined by structure ex-
tending between the front and rear frame members of plug
assist assembly 108, with the opening having a cross sec-
tion corresponding to and slightly larger than the cross
section of post 192. Similarly, post 194 is received
within an opening 195 defined by structure extending be-
tween the front and rear frame members of plug assist
assembly 108, with the opening providing a cross section
corresponding to and slightly larger than the cross section
of post 194. With this arrangement, posts 192 and 194
ensure vertical movement of plug assist assembly 108 during
operation of linear actuator assemblies 162, 164 in re-
sponse to operation of servo motors 170, 176. It is under-
stood that any other satisfactory arrangement could be
employed for this purpose, e.g. a mating channel and pro-
jection type system.
Forming members 186, 190 are shown in their
lowermost position in solid lines in Fig. 6. Forming
member 190 is shown in its raised position in phantom.
In accordance with known principles, forming
members 186, 190 engage lower web 14 and move lower web 19
downwardly, to assist it in conforming to the forming
cavities of forming box 98.
Referring to Figs. 1 and 2, after the formed
lower web is discharged from forming station 18 where it is
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PGT/US91 /09279
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deformed to provide side-by-side product cavities, the
product, shown at P in Fig. 1, is loaded into the product
cavities at loading station 20. Product P may be loaded in
any satisfactory manner, such as by hand or by an automated
loading system. Product P as illustrated in Fig. 1 com-
prises hotdogs, but it is understood that product P could
be any product which is satisfactorily packaged in the
manner disclosed, such as ham, bacon, sliced luncheon meat,
cheese, pharmaceuticals, or the like.
After the product cavities are loaded with prod-
uct P, the formed and loaded lower web is moved to upper
web supply station 22.
Upper web supply station 22 (Fig. 2) is arranged
similarly to lower web supply station 12, and functions in
a similar manner. Upper web supply roll 24 is rotatably
supported on a shaft 196 stationarily mounted to a bracket
assembly 198. A pair of vertical frame members 200, 202
extend upwardly from upper frame members 28 of packaging
machine 10, for supporting upper web supply station 22.
An unwinding drive assembly, shown generally at
204, is mounted to the frame of upper web supply station 22
for unwinding upper web material from supply roll 24. The
components of unwind drive assembly 204 are the same as
those described previously with respect to lower web supply
station 12, and function in the same manner as such compo-
nents. Upper web supply station 22 further includes a
dancer assembly 206 which functions in the same manner as
the dancer assembly located at lower web supply station 12,
for providing selective unwinding of upper web material
from supply roll 24 by unwind drive assembly 204 in re-
sponse to indexing movement of the upper web along with the
formed and loaded lower web.
At downstream station 26, a vacuum box 208 is
mounted to a frame 210, and is operable in accordance with
known vacuum packaging principles to evacuate the product
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-18-
cavities while the upper and lower webs are sealed togeth-
er, to provide a vacuum package of product P. A heating
assembly 212 is located at downstream station 26 to acti-
vate sealant on the upper web and lower web 14.
Frame 210 is movable between a raised and lowered
position in the same manner as frame assembly 100 located
at forming station 18. A lift servo motor 214 is provided
for imparting selective lifting and lowering of a pair of
lift arms, one of which is shown at 216, through a timing
belt and pulley arrangement similar to that described
previously at forming station 18.
After the product cavities are evacuated and the
upper and lower webs are bonded together to provide a
vacuum package for product P, the bonded upper and lower
webs are advanced to a cutting station, shown generally in
Fig. 2 at 218. As the webs exit cutting station 218, a
centrally located cutting blade severs the webs longitudi-
nally to separate the two lanes of formed packages. Prior
thereto, a cross-cut mechanism, shown in Fig. 7 generally
at 220, then severs the webs transversely.
Cross-cut mechanism 220 includes a frame assembly
including an upper frame member 222 and a bracket member
224, which is pivotably mounted to a support member 226
mounted to upper frame member 28 of packaging machine 10.
A bracket member 228 is located at the other end of upper
frame member 222, and is connected to the extendable and
retractable output member 230 of a cylinder assembly shown
generally at 232. A bracket 234 connects the lower end of
cylinder assembly 232 to a support member 236, which is
interconnected with frame member 28 of packaging machine
10.
Cylinder assembly 232 may be any satisfactory
assembly for raising and lowering output member 230, such
as a pneumatic or hydraulic cylinder, or a solenoid-type
arrangement. With this construction, upper frame member
_ _.
WO 92/10405 ~ ~ ~ ~ ~ ~ ~ PCT/US91/09279
-19-
222 is movable between a lowered position as shown in Fig.
7, and a raised position.
A rodless pneumatic cylinder 238 is mounted to
the underside of upper frame member 222, and a carriage 290
is connected to the movable output member of rodless cylin-
der 238. A pair of blade holder assemblies 242, 294 are
mounted to the ends of carriage 240, and retain a pair of
knife blades 246, 248.
Operation of rodless cylinder 238 provides a
cutting stroke to carriage 240 for drawing blades 246, 248
rightwardly through the upper and lower webs, to trans-
versely sever the webs. The output member of rodless
cylinder 238 is first moved to its leftwardmost position,
so that blade 246 is disposed leftwardly of the leftward
edges of the upper and lower webs, and blade 248 is located
in the area between the two lanes of formed packages.
Output member 230 of cylinder assembly 232 is then retract-
ed, so that the points of blades 246, 248 pierce the upper
and lower webs. Rodless cylinder 238 is then operated to
move carriage 240 rightwardly, and blades 246, 248 cut
through the upper and lower webs to completely sever the
webs. Upon a full cutting stroke of rodless cylinder 238,
blade 246 is moved rightwardly an amount sufficient to
sever the webs up to the point where blade 248 initially
pierced the webs. Blade 248 is moved completely through
the webs to clear the rightward edges of the webs. Output
member 230 of cylinder 232 is then extended to raise blades
246, 248 above the webs, and the output member of rodless
cylinder 238 is then moved leftwardly to bring the blades
back to their original position, whereafter output member
230 is again retracted to bring blades 246, 248 into con-
tact with the webs.
Blades 246, 248 are conventional blades as used
in a utility knife or the like, and therefore are rela-
tively inexpensive and are readily available. This reduces
WO 92/10405 ~~ PCT/US91/09279_
-20-
an operator's costs, since blades must often be replaced
during operation of packaging machine 10.
Blade holder assemblies 242, 244 are constructed
so as to provide quick and easy interchangeability of
blades 246, 248, thus minimizing downtime of packaging
machine 10 for blade replacement.
Referring again to Fig. 1, a control module 250
is mounted to an arm 252, which is pivotably connected to
the upper end of the frame of upper web supply station
22. Control module 250 can be moved to varying positions
by the operator of machine 10, who normally is positioned
at loading station 20.
Control module 250 includes a touch screen 254
for controlling the operation of servo motors 78, 110, 170,
176 and 214. In accordance with known technology, the
operation of the servo motors is controlled by programmable
controllers, thereby providing very fine control of the
position of the servo motor output shafts, and thereby of
the packaging machine components driven by the servo mo-
tors. This is in marked contrast to prior art indexing-
type packaging machines, which typically employ pneumatic
cylinders for providing up and down movement of the plug
assist members and the forming and evacuating boxes, and a
continuously operating motor with a Geneva drive system for
providing indexing advancement of the packaging webs. The
servo motors are programmed so as to provide smooth and
even acceleration and deceleration of the driven components
and rapid intermediate movement for moving the components
from one position to another. In this manner, the servo
motor driven components of packaging machine 10 can be
operated at a very high rate of speed, providing a dramati-
cally increased rate of package production over convention-
al indexing-type machines, as well as an increased rate of
production relative to continuous motion-type machines.
_ .r __...
fVO 92/1040 U5
PCT/US91/09279
-21-
Another advantage offered by the use of servo
motors in machine 10 is that the operating parameters can
be varied by changing the program which controls the opera-
tion of the servo motors. The operating parameters are
varied by use of the operator interactive touch screen 254.
For example, chains 88a and 88b lengthen slightly over time
due to wear of the links. In a conventional indexing-type
machine, this problem is addressed by changing the position
of the forming box. With the packaging machine of the
invention, the operator simply changes the operating param-
eters to shorten the length of the indexing web repeat,
thus minimizing machine down time.
Fig. 8 illustrates the various modes of operation
selectible on touch screen 254. On start-up of machine 10,
a start-up screen 256 appears, and the operator can touch
one of areas 258, 260, 262 or 264 to select one of screens
266, 268, 270 or 272, which respectively comprise an auto-
matic run operator screen, a recipe select screen, a clean-
up screen and a maintenance menu screen. Maintenance menu
screen 272 can only be selected upon entry of a maintenance
password, represented at 274. After the various parameters
are set on the appropriate screen, the operator pushes the
"start" button associated with a button panel 276 (Fig. 1),
tc> commence operation of machine 10.
As also shown in Fig. 1, an enclosure 278 con-
tains the componentry which controls the operation of the
servo motors associated with packaging machine 10. Refer-
ring to Fig. 9, enclosure 278 houses a programmable motion
control computer 280, which is interconnected with the
operator interface control module 250. Computer 280 pro-
vides output signals to control amplifiers, such as shown
at 282, 284, 286 and 288. Amplifiers 282, 284, 286 and 288
provide control signals to servo motors 78, 170, 176, 110
and 214, respectively, to control the operation of the
motors and therefore the position of the respective motor
WO 92/10405 Q~~ ~ PCT/US91/09279 --
-22-
output shafts. Servo motors 78, 170, 176, 110 and 214
include position sensors and feedbacks 290, 292, 294, 296
and 298, respectively, for conveying to computer 280 the
actual positions of the motor output shafts. In this
manner, the actual shaft position is compared with the
programmed shaft position, and the motor speed is adjusted
to move the motor shafts to the appropriate positions.
A power supply 300 provides power for operating
the servo motors through control amplifiers 282-288, re-
spectively.
The servo motors are preferably such as manu-
factured by the Gettys Corporation of Racine, Wisconsin
under catalog number M324-P70A-1001. The motors provide
rotary output power to cycloidal type gear reducers, of
conventional technology. Suitable reducers are those such
as manufactured under the trademark "SM-Cyclo" by Sumitomo
Machinery Corporation of America, under Model No. H3105HS.
The control amplifiers employed with the servo motors are
preferably such as manufactured by Gould, Inc./Motion
Control Division of Racine, Wisconsin under Model No. A700.
The programmable motion control computer 280 may be such as
manufactured by Giddings & Lewis Electronics under its
Model No. PiC49.
Reference is now made to Figs. 10-14, which
illustrate cutting station 218 of packaging machine 10 in
greater detail. As shown in Fig. 11, which is somewhat
similar to Fig. 7, cross-cut assembly 220 includes upper
frame member 222, bracket 224 and support member 226, which
cooperate to pivotably mount one end of frame member 222 to
packaging machine frame member 28. Bracket 228 is located
at the other end of frame member 222 and is connected to
the extendable and retractable rod 230 of pneumatic cylin-
der assembly 232, which is interconnected with the left-
hand frame member 28 of packaging machine 10 through brack-
et 234 and support member 236. Cylinder assembly 232 is
_ .r _ _ 1
p PCT/US91 /09279
E )92/10405
_23 ~0~,~~~~
operable to move frame member 222 between a lowered posi-
tion, shown in solid lines in Fig. 11, and a raised posi-
tion, shown in phantom. Movement of frame member 222 to
its lowered position prepares cross-cut assembly 220 for a
cutting stroke, and a return stroke is provided upon move-
ment of frame member 222 to its raised position.
Rodless cylinder 238, which is mounted to the
underside of frame member 222 by means of a pair of brack-
ets 300, 302, comprises a magnetic cylinder assembly such
as manufactured by SMC Pneumatics, Inc. of Indianapolis,
Indiana, under its designation Series NCY1, which includes
an internal reciprocating piston coupled by magnetic force
to an output member. The output member of rodless cylinder
238 is encased within a UHMw polyethylene block 306.
Carriage member 240, which is constructed of stainless
steel, is secured by bolts or the like through the lower
portion of nylon block 306 to the output member of cylinder
238, so as to be movable therewith during movement of the
output member. Blade holder assemblies 242, 244 are formed
at the ends of carriage member 240, and knife blades 246,
248 are mounted to blade holder assemblies 242, 249, re-
spectively in a manner as will be explained.
When frame member 222 is moved to its lowered
position, in which a cutting stroke of blades 246, 248 is
provided, frame member 222 is oriented at an angle of
approximately 3° to horizontal, as is cylinder 238 and
carriage member 240. With this arrangement, blade holder
assemblies 242, 249 and blades 246, 248 travel slightly
uphill during the cutting stroke of cross-cut assembly 220.
Reference is now made to Fig. 12 for a detailed
description of blade holder assembly 242. It is to be
understood that blade holder assembly 249 is constructed in
a manner similar to that of blade holder assembly 242, and
that the following description applies with equal force to
blade holder assembly 244.
wi'O 92/ I 0406 _ PCT/US91 /09279
' 207 58 04 -29-
As noted previously, blades 246, 298 are conven-
tional blades as used in a utility knife, which are rela-
tively inexpensive and are readily available. The particu-
lar blade illustrated in Fig. 12 is that such as manufac-
tured and sold by The Stanley works of New Britain, Con-
necticut, as a replacement blade for a Stanley*utility
knife. The edge of blade 246 parallel and opposite to the
sharpened edge is provided with a pair of notches, shown at
308, 310. Notches 308, 310 are located one on either side
of the center of blade 246, and are intended to be received
within a projection associated with a blade-receiving
portion of a conventional utility knife, to determine the
amount of projection of the sharpened edge of blade 246
from the front end of the utility knife.
Blade holder assembly 242 essentially consists oT
a block having a groove 312 formed in its front face.
Groove 312 has a depth of approximately 1/8 inch to 3/16
inch, which is sufficient to receive the entire thickness
of blade 246 therewithin. Groove 312 has a width o:~ly
slightly greater than the width of blade 296 from its
sharpened edge to its non-sharpened edge. Groove 312 is
oriented such that the sharpened edge of blade 246 is
disposed at an angle of approximately 28° to vertical when
blade 296 is received within groove 312.
Blade 246 is maintained within slot 312 by means
of a series of magnets, shown in Fig. 12 at 314, 316.
Magnets 314, 316 are mounted in a bore 318 formed in the
front face of blade holder 242. A magnet holder member 320
is provided with openings which receive magnets 314, 316
therewithin, ,end is adapted for placement within bore 313
so as to firmly and securely retain magnets 314, 316 on
magnet holder assembly 292 in bore 318. The forward faces
of magnets 319, 316 are flush with the bottom surface of
groove 312.
*Trade Mark
~'O 92/10405 ~ Q ~ ~ ~ 0 ~ PCT/US91/09279
-25-
A peg 322 is mounted to blade holder assembly 242
adjacent the edge of groove 312 against which the non-
sharpened edge of blade 246 is placed. Peg 322 is adapted
to be received within one of the notches 308, 310 when
blade 246 is mounted within groove 312 of blade holder
assembly 242.
To mount blade 246 to blade holder assembly 242,
the operator simply inserts the blade into groove 312 such
that the sharpened edge of blade 246 is positioned adjacent
one of the side walls of groove 312, and the non-sharpened
edge is positioned adjacent the other side wall of groove
312. The lowermost of notches 308, 310 is positioned so as
to receive peg 322 therewithin, and magnets 314, 316 then
magnetically retain blade 246 within position in groove
1.5 312. The engagement of peg 322 within notch 308 fixes the
vertical position of blade 246 relative to blade holder
assembly 242. After blade 246 is positioned within groove
312, with peg 322 engaged within notch 308, the engagement
of the edges of blade 246 with the side walls of groove 312
prevents movement of blade 246 during operation of cross-
cut assembly 220.
When the lower portion of blade 246 becomes dull
by use, the operator can manually remove blade 246 from
groove 312 by pulling outwardly on blade 246, and flip
blade 246 end for end to expose an unused portion of the
sharpened edge of blade 246. The operator positions blade
246 such that peg 322 is engaged within notch 310, to once
again provide proper vertical positioning of blade 246.
After both ends of blade 246 have been used and dulled, the
operator replaces blade 246 in a manner as described previ-
ously, by manually removing blade 296 and positioning a
replacement blade within crroove 312.
with the arrangement as shown and described,
blade replacement is extremely quick and simple, and re-
quires no tools. In the past, blades have been held in
WO 92/10405 ~~~~ PCT/US91/09279 .
-26-
place by inserting a screw through an opening formed in the
blade, and engaging the screw with a threaded opening
formed in the blade holder assembly. The blade holder as
shown and described eliminates this step, and constitutes a
significant improvement over the prior art.
Referring to Fig. 13, a pair of identical cross-
cut assemblies 220 are provided at cutting station 218.
Downstream of cross-cut assemblies 220 is located a longi-
tudinal slitting mechanism, shown generally at 330, for
slitting the transversely cut webs to provide discrete
product packages. Slitting mechanism 330 includes a rotat-
ing bar 332 having a series of slitters mounted thereto.
Each slitter consists of a hub 334 and a blade 336. A
series of slitter blocks 338 are mounted below slitting
mechanism 330, and each includes a groove within which
slitting blade 336 is located. Slitting blocks 338 are
narrow enough to fit between the formed packages, and each
includes a sloped leading surface.
Referring to Figs. 10, 11 and 14, a pair of
cross-cut platens 340 are disposed below cross-cut assem-
blies 220. Platens 340 consist of UHMW polyethylene blocks
mounted to a cross-member 342, which is supported at its
ends by a pair of upright members 344, 346. Upright mem-
bers 344, 346 are secured to frame 210, which is movable
between a raised and lowered position as described previ-
ously, in response to operation of lift servo motor 214 and
a pair of lift arms, one of which is shown at 216. Platens
340 are narrow enough to fit between the formed product
cavities, and are located at an elevation which, when frame
210 is moved to its raised position, causes engagement of
the upper surface of platens 340 with the underside of
lower web 14, to lift webs 14 and 24 and to introduce
tension therein during the cross-cut operation. Platens
340 are provided with a longitudinal slot which receives
blades 246, 248 therewithin when cross-cut assembly 220 is
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CVO 92/10405 '~ "~ ~' ~ ~ ~ PCT/US91/09279
-27-
moved to its lowered position. Alternatively, the material
of platens 340 on one side of the slot may be removed,
forming a shoulder against which the blade is positioned.
To perform the cross-cut operation, cylinder 232
is operated to move frame member 222 to its raised posi-
tion, and frame 210 is moved to its lowered position so as
to move platens 340 out of the path of webs 14, 24 which
have been formed into packages. The webs are then index-
ingly advanced forward, and frame assembly 210 is then
moved to its raised position to bring platens 340 into
engagement with the underside of web 14 and to introduce
tension into the webs. Simultaneously, cylinder assembly
232 is operated to retract its rod 230, and to move frame
member 222 to its lowered position. This causes piercing
of' webs 14, 24 by blades 246, 248. Air pressure is then
introduced into cylinder 238 to move its output member
ri.ghtwardly, and along with block 306, resulting in a
cutting stroke of cross-cut assembly 220. During the
cutting stroke, the slight angle of inclination of cylinder
238 results in blades 246, 298 traveling uphill, thus
utilizing more than a single point of the sharpened edge of
blades 246, 248 to perform the cutting of webs 14, 24.
Blade 246 initially pierces webs 14, 24 outwardly of the
farmed product cavity, and blade 248 pierces the webs
substantially at the center of the central product cavity.
During the cutting stroke, blade 246 is moved rightwardly
so as to sever webs 14, 24 up to the point of piercing of
the webs by blade 248. Simultaneously, blade 248 is moved
rightwardly past the outer edge of the rightwardmost prod-
uct package. In this manner, webs 14, 24 are severed
substantially across their entire width, excepting the
portion of webs 14, 24 which is engaged by the clip chains
88a, 88b.
After the cutting stroke of cross-cut assembly
220 is completed, cylinder 232 is operated to move frame
WO 92/10405 j~~ ~~ PCT/US91/09279 -
_28_
member 222 to its raised position, thus withdrawing blades
296, 248 above webs 14, 29. Platens 340 are simultaneously
withdrawn from below webs 19, 24 by lowering of frame
assembly 210, and the webs are moved to slitting mechanism
330. Slitter blades 336 then longitudinally sever webs 14,
24 into discrete product packages. The outer portion of
webs 14, 24 is retained by the clip chains, and is eventu-
ally discharged therefrom and discarded as waste.
Various alternatives and embodiments are con-
templated as being within the scope of the following par-
ticularly pointing out and distinctly claiming the subject
matter regarded as the invention.
______. ~ ~.._.._.. . _.._
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