Note: Descriptions are shown in the official language in which they were submitted.
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MA88 FEEDER FOR PRODOCT DELIVERY SygTEM
FjFT.D llTr TV1: rlm~~rw~.
The invention generally relates to a system for
delivering~a plurality of products and, more particularly,
to a system that delivers a number of partitions which are
to be positioned between beverage containing articles.
BACRGROO1QD OF THE .u'~'TOr1'
When packaging articles, such as bottles or cans, into
a carton or other suitable container, the articles are
to typically separated into discrete groups and each group of
articles is then placed into a carton. Frequently, an
insert or partition is placed between the articles to
prevent the articles from colliding into each other and
causing damage to the integrity of the articles or damage
to the graphics on the articles. The partitions may serve
other functions as well, such as forming part of the
carton. The partitions are placed between the articles
after the articles have been separated into a discrete
group but before the articles are placed into the cartons.
In a typical packaging machine, a partition feeder
holds a stack of the partitions in a supply hopper. The
stack of partitions are formed between two sides of the
' supply hopper and rest against the bottom of the hopper.
The stack is releasably retained within the supply hopper
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by a set of tabs which contacts the first partition in the
stack. The stack of partitions are biased toward the tabs
by either the weight of the stack and/or by a pusher or
other similar type of mechanism which pushes the rear end
of the stack.
A selecting apparatus typically has a set of vacuum
cups which move forwardly against the first partition and
then move away from the partition feeder in order to remove
the one partition from the stack. The tabs are carefully
positioned so that they permit the removal of the first
partition by the vacuum cups but prevent the other
partitions from being removed along with the first
partition. After removing the partition, the selecting
apparatus releases the partition from the vacuum cups and
places the partition between adjacent articles in a
discrete group.
The ability of the selecting apparatus to pick a
single partition is influenced by a number of factors,
including the extent to which the tabs contact the
partitions, the pressure in the vacuum cups, and the force
applied through the partitions to the tabs. With many
partition feeders, the stack is formed at a downward angle
so that the weight of the stack itself generates a force at
the tabs. This force is necessary to ensure that
subsequent partitions are advanced into the proper position
after previous partitions have been removed by the .
selecting apparatus. The force is also necessary so that
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vacuum cups in the selecting apparatus do not knock the
partitions out of position when they move against the first
partition for a pick. The magnitudes of the pressure in
the cups, the force at the tabs, and the amount of tabbing
must be fairly accurately set in order for the selecting
apparatus to consistently and reliably remove a single
partition from the supply hopper.
The advancement of the partitions, however, may be
hampered by the supply hopper. For instance, the surfaces
l0 of the sides and bottom of the supply hopper fractionally
engage the partitions rendering it difficult for the
partitions to advance. At times, a gap forms between
adjacent partitions due to one partition advancing at a
different rate than the other partition. These gaps
disrupt the order of the stack and affect the magnitude of
the force applied by the stack against the tabs. Also,
during the refilling of the supply hopper, the partitions
may fall down so that the fronts of the partitions face the
bottom of the supply hopper. It was therefore difficult
with existing supply hoppers to ensure that the partitions
remain in alignment With each other.
The supply hopper may present additional problems.
Due to the friction generated by the sides and bottom of
the supply hopper, a relatively large force must be used to
overcome the frictional engagement of the supply hopper.
This relatively large force, in turn, requires that the
tabbing be heavy, i.e. must extend further into the
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partitions, and that the pressure in the cups be large so
that a partition can be removed from the heavy tabbing.
Because the partitions are being subjected to a heavy
tabbing and a large pressure, the partitions must be strong
enough so that they do not tear or otherwise become
damaged. The packaging machines are therefore limited in
the types of partitions that can be used in the cartons.
In order to maintain a sufficient force at the tabs,
the weight of the stack should not fall below a certain
1o amount. Consequently, during operation of the partition
feeder, an operator must periodically refill the partition
feeder so that the stack stays above this certain amount.
When the packaging machine operates at faster rates, the
partition feeder must be more closely supervised by the
operator since the partitions are removed from the supply
hopper at a quicker rate. A need therefore exists in the
industry for a partition feeder which requires less
supervision and which is therefore less labor intensive.
The partition feeders are typically mounted above the
flow of articles, with the supply hopper being about 7 or
8 feet above the ground. The operators of the partition
feeder therefore need a step ladder or some type of raised
platform with steps in order for the operator to add the
partitions to the supply hopper. The time and energy
expended by the operator in going up and down the steps
further burdens the operator and results in an overall more
costly packaging operation.
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Many packaging machines can only package one size of
articles and just one configuration of articles. For
~ instance, a packaging machine might be limited to just a
standard American size bottle that is packaged into a 12
~ 5 pack container. Another packaging machine would be
designed to package articles having a different size
article or to package articles into a different size
container.
Some recently manufactured packaging machines,
however, have some flexibility in that they can package
articles of different sizes into various types of
containers. While these machines may have the capability,
it is relatively difficult to adjust the packaging machines
to package another article size or another configuration.
The adjustments necessary on the packaging machines include
an adjustment in the partition feeder for a different size
partition. This adjustment might encompass the replacement
of one supply hopper with a supply hopper that could hold
the new partitions. A need therefore exists in the
industry for a partition feeder that can supply partitions
of different sizes.
SUM11ARY OF THE INVENTION
The invention, in one aspect, comprises a mass feeder
that has a pair of side rails for forming a main stack of
products. The mass feeder has at least one tab at one end
of the side rails for contacting an end product in the main
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stack. A number of reserve stacks of products are formed
such that the reserve stacks are spaced above each other
with a top reserve stack being aligned with the main stack
of products. The mass feeder has a first pusher for
advancing the main stack toward the tab and has a second
pusher for adding the top reserve stack to the main stack.
A controller in the mass feeder removes the first pusher
from contact with the main stack when the top reserve stack
approaches the main stack and thereafter causes the second
pusher to advance the main stack toward the tab after the
products in the top reserve stack have been added to the
main stack.
The invention, in a second aspect, comprises an
apparatus for forming a main stack of products and for
forcing the products against a set of tabs at one end of
the stack. The apparatus forms at least one reserve stack
of products and moves the reserve stack into alignment with
the main stack at an end of the stack opposite the end with
the tabs when the main stack has been reduced down to a
predetermined amount.
The invention, in a third aspect, comprises a multi-
rack assembly for forming reserve stacks of products. The
multi-rack assembly has a first drive unit with a pair of
vertically spaced paddles and a second drive unit with
another pair of vertically spaced paddles. The paddles on
the two drive units are vertically spaced the same distance
and are spaced apart from a corresponding paddle on the
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other drive unit a distance sufficient to form a first
reserve stack between the upper paddles and a second
reserve stack between the lower paddles. A controller
generates a control signal when additional products are
needed in a main stack and also causes the drive units to
simultaneously raise the bottom paddles into alignment with
guide rails forming the main stack. In this manner. tha
reserve stacks of products may be added to the main stack
when additional products are needed in the main stack.
The invention, in a fourth aspect, comprises a multi-
rack assembly for forming reserve stacks of products having
a left drive unit for rotating a first set of paddles about
a periphery of the first drive unit in a counter-clockwise
direction and a right drive unit for rotating a second set
of paddles in a clockwise direction about a periphery of
the second drive unit. The paddles on the two drive units
are aligned with each other such that the paddles on the
interior sides of one drive unit are laterally spaced a
distance from corresponding paddles on the interior side of
the other drive unit, with the distance being sufficient to
form a reserve stack of products between each laterally
spaced pair of paddles. One of the laterally spaced pair
of paddles is aligned with and parallel to a pair of guide
rails which form a main stack of products. A controller
drives the first and second motors in synchronism with each
other so as to move the one pair of laterally spaced
paddles out of alignment with the guide rails and to move
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a second pair of laterally spaced paddles into alignment
with the rails whey the main stack of products has been
reduced down a certain amount.
The invention, in a fifth aspect, comprises a
partition feeder for use with partitions having notched
sides. The partition feeder has first and second spaced
apart guide rails for respectively receiving the notched
sides of the partitions and for forming a main stack of the
partitions. At least one tab is placed at one end of the
guide rails for contacting one end of the stack and a
selecting apparatus removes the partitions from the one end
against contact with the tab. The partitions are biased
toward the one end of the guide rails. The guide rails
suspend the partitions and allow the partitions to freely
advance toward the one end of the guide rails.
The invention, in a sixth aspect, comprises an
adjustable frame for a partition feeder which forms a main
stack of partitions between first and second side rails.
A first frame mounts at least a part of the feeder at a
specific location relative to a flow of articles and has
first and second walls spaced apart from each other a fixed
distance. A second frame has first and second plates
positioned between the first and second walls with the
first and second side rails being respectively mounted to
the first and second plates. The first and second plates
are mounted to the first and second walls in a manner which
allows the first and second plates to travel between the
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two walls. The distance between the first and second
plates can be adjusted to thereby adjust the distance
between the first and second side rails to correspond to a
width of the partitions.
The invention, in a seventh aspect, 'comprises an
adjustable frame for a partition feeder which forms a main
stack of partitions between first and second side rails.
A first frame is mounted at a predetermined height above a
flow of articles and a second frame has at least the side
rails of the feeder mounted thereon. The second frame is
attached to the first frame in a manner which allows the
second frame to be raised or lowered with respect to the
first frame so as to place the second frame at a desired
distance from the first frame. The distance between the
first frame and the side rails can therefore be adjusted to
correspond to a height of the partitions.
BRIEF DESCRIPTION OF 'PEE DRAWINGS
Fig. 1 is a front perspective view of a mass feeder
according to the preferred embodiment of the invention;
Fig. 2 is a partial side view of the mass feeder shown
with a selecting apparatus;
Fig. 3 is a partial rear perspective view of the mass
feeder of Fig. 1;
Fig. 4 is a rear perspective view of the mass feeder
of Fig. 1;
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Fig. 5 is a rear end view of the mass feeder of Fig.
1;
Fig. 6 is an exploded view of a drive unit in a multi-
rack assembly;
Fig. 7 is a block diagram of the mass feeder of Fig.
1;
Fig. 8 is a flow chart of a routine for controlling
the multi-rack assembly.;
Fig. 9 is a flow chart of a routine for controlling a
pusher; and
Fig. 10 is a partial perspective view of an adjustment
frame.
DETAINED DESCRIPTION OB T8E PREFERRED ENEOD7Ck1ENT8
With reference to Fig. 1, a preferred embodiment of a
partition feeder 10 has a pair of guide rails 12 extending
along a longitudinal length of the feeder 10. Each guide
rail 12 is generally wedge-shaped with a generally planar
top surface 12a and an angled side surface 12b. A stack of
partitions 14 have notched sides for mating with the wedge-
shaped guide rails 12, with the generally planar top
surface 12a of the guide rails 12 supporting the partitions
14. The guide rails 12 form a stack of partitions 14 along
the length of the guide rails 12 with each partition 14
suspended upon the guide rails 12. The guide rails 12 are
formed of a relatively low friction material, such as an
ultra-high molecular weight (LTHIdW) plastic, which enables
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the partitions 14 to advance easily toward a set of tabs
18. The guide rails 12 are not limited to UHIHW, but may be
formed from any suitable material.
The guide rails 12 offer several advantages over the
supply hopper of a conventional partition feeder. For one,
an operator can easily load the partitions 14 by simply
aligning the notched sides of the partitions 14 with the
guide rails 12. The guide rails 12 ensure that the
partitions 14 remain in alignment with each other in the
1o stack since the partitions 14 cannot fall down or otherwise
become disordered relative to the other partitions 14.
Also, the guide rails 12 present a minimal amount of
resistance to the partitions 14. Whereas before the
partitions 14 would contact the sides and bottom of a
supply hopper, the partitions 14 in the partition feeder 1o
of the invention only contact the guide rails 12 at their
notched sides.
In the embodiment shown, the partitions 14 are held
within the stack by four tabs 18 respectively located at
the four corners of the first partition 14. The bottom two
tabs 18 are mounted to an outer frame 162 of the feeder 10
by adjustable brackets 1.6, which allow both horizontal and
vertical adjustment of the tabs 18. The top two tabs 18
are adjustably,mounted to a cross-bar 20 which has its two
ends respectively affixed to a lever 22 and to a bell crank
24. The stack of partitions 14 is forced against the tabs
18 by a pusher 26 at the rear end of the stack.
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The force supplied by the stack against the tabs 18
pushes the cross-bar 20 outwardly thereby rotating the bell
crank 24 and lever 22. When the bell crank 24 rotates, the
bell crank 24 compresses a urethane spring 28 having one end
placed against a load bearing surface of a load cell 30.
The force at the tabs 18 is therefore transferred through
the cross-bar 20, bell crank 24, and urethane spring 28
before reaching the load cell 30. The control of the force
at the tabs 18 by detecting the force with a load cell
assembly is the subject matter of commonly-assigned U.S.
Patent No. 5,585,568 entitled "Force Sensing Assembly and
Method for a Product Delivery System".
A selecting apparatus 32 , which is shown in Fig . 2 , has
a set of vacuum cups 34 to remove a partition 14 against
contact from the tabs 18. Once a partition 14 is removed by
the apparatus 32, the partition 14 is placed between a group
of articles, such as bottles traveling below the selecting
apparatus 32. The selecting apparatus 32 does not form any
part of the present application and any suitable apparatus
for removing a partition may be used. A preferred selecting
apparatus 32, however, is disclosed in commonly-assigned
U.S. Patent No. 5,564,894 entitled "Article Selection and
Delivery Method and Apparatus".
As best seen in a rear cut-away view shown in Fig. 3,
the partition feeder 10 has two screw drives 38 running
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along the length of the feeder 10. A pusher assembly 45,
comprised of a rotary actuator 40 and a pusher 26, is
connected to each screw drive 38 and has a bearing 41 for
mounting the pusher assembly 45 to a linear guide 43
extending along the length of the feeder 10. The rotary
actuators 40 lower and raise their respective pushers 26 in
a manner that will be described in more detail below. A
stepper motor 42 is connected td each screw drive 38
through a set of gears 44. By controlling the speed and
direction of the stepper motors 42, the screw drives 38 can
be rotated in either direction to move the pushers 26
toward or away from the tabs 18 and to move the pushers 26
at different speeds.
During operation of the pushers 26, only one pusher 26
at a time will be pushing a main stack of partitions 14
toward the tabs 18. At times, however, the other pusher 26
may be moving partitions 14 from a reserve stack toward the
main stack and, consequently, toward the one pusher 26. It
is therefore necessary to detect the various positions of
the rotary actuator 40 and of the pusher 26 throughout the
operation of the partition feeder 10.
The partition feeder 10 has a number of sensors for
indicating the positions of the rotary actuator 40 and of
the pusher 26. As best seen in Fig. 7, each rotary
actuator 40 is connected to a first pneumatic line 103 for
raising the pusher 26 and a second pneumatic line 105 for
lowering the pusher 26. The pneumatic lines 103 and 105
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are connected to a supply of pressure 109. While the
position of the pusher 26 can be deduced from which
pneumatic line 103 or 105 has been activated, each rotary
actuator 40 is provided with two feedback sensors 107 for
indicating whether its pusher 26 is in the raised position
or whether the pusher 26 is in the lowered position.
As shown in Fig. 3, a first set of four proximity
sensors 51 is mounted to a middle frame 164 of the
partition feeder 10 at each end of both screw drives 38.
The first proximity sensors 51 detect a metal flag 61,
which in this example is a bolt 61 that mounts a second
proximity sensor 52 to the pusher assembly 45 . The first
proximity sensor 51 therefore provides an indication as to
whether the pushers 26 are at either end of the screw
drives 38.
The second proximity sensor 52 is mounted at an upper
portion of each pusher assembly 45 for detecting a metal
ridge 62 that runs along a partial length of the partition
feeder l0. The metal ridge 62 has a first end 62a at a
predetermined point along the length of the screw drives 38
and has the other end 62b at the end of the screw drives 38
near the tabs 18. The second proximity sensor 52 provides
an indication that the pusher 26 has moved past the
predetermined point during its travel toward the tabs 18.
The significance of this predetermined point will be
discussed in more detail below.
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A third proximity sensor 53 is mounted to a horizontal
bracket 58 on each pusher assembly 45. One of the brackets
' S8 has an upwardly extending metal flag 63 and has the
third proximity sensor 53 mounted to the bottom of the
bracket 58. The other bracket 58 has the flag 63 and third
proximity sensor 53 placed in reverse positions, that is
the flag 63 extends down from the bracket 58 and the third
proximity sensor 53 is mounted on the top of the bracket
58. If the pushers 26 pass each other when traveling in
opposite directions, the bottom mounted proximity sensor 53
of the one pusher 26 will detect the downwardly extending
metal flag 63 on the other pusher 26 and the top mounted
proximity sensor 53 of the other pusher 26 will detect the
upwardly extending metal flag 63 on the one pusher 26. The
third proximity sensors 53 allow each pusher assembly 45 to
detect the approach of the other pusher assembly 45 so that
the pushers 26 may be raised or lowered to prevent the
pushers 26 from colliding into each other.
Each pusher 26 is mounted with a photoelectric eye
("photoeye") 56 which looks straight down to detect the
approach of additional partitions 14. As discussed above,
as one pusher 26 is advancing the main stack of partitions
14 to the tabs 18, the other pusher 26 may be adding
partitions 14 to the main stack. The photoeye 56 on the
pusher 26 detects the arrival of the additional partitions
14 so that the pusher 26 may be raised to add the
partitions 14 in the reserve stack to the main stack.
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As best seen in Figs. 3 and 4, the partition feeder 10
has a multi-rack assembly 70 for holding three reserve
stacks 72 of partitions 14 between pairs of opposing
paddles 74. The three reserve stacks 72 are vertically
spaced from each other with the paddles 74 forming the top
stack 72a being aligned with the guide rails 12 forming the
main stack of partitions 14. Two photoeyes 76 detect
whether gartitions 14 are present in the lower two reserve
stacks 72b and 72c. When the main stack has diminished
past a predetermined amount, which occurs when the second
proximity sensor 52 on the rotary actuator 40 detects the
metal ridge 62, the paddles 74 may be rotated to advance a
reserve stack 72 of partitions 14 into alignment with the
main stack.
The multi-rack assembly 70 is comprised of two drive
units 80 with six paddles 74 mounted to chains 82 of each
drive unit 80. As best seen in Fig. 6, each drive unit 80
has a synchronous lift motor 84 for rotating a drive shaft
86 through a first pulley 88, a second pulley 90 on the
drive shaft 86, and a belt 92 interconnecting the two
pulleys 88 and 90. Sprockets 94 are located at both ends
of the drive shaft 86 and at both ends of a second shaft 96
located near the bottom of the drive unit 80. The pair of
chains 82 link the sprockets 94 on the drive shaft 86 to
the sprockets 94 on the bottom shaft 96. Brackets 98 on
the paddles 74 mount the paddles 74 to the chains 82 at ,
equal intervals along the length of the chains 82.
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A proximity sensor 93 is positioned between the first
pulley 88 and the chain 82 and a metal flag 95 is affixed
to a surface of the pulley 88 that faces away from the
motor 84. The proximity sensor 93, which is secured to a
bracket-97 attached to one of two chain guards 99, faces
the pulley 88 and detects the metal flag 95 upon each full
rotation of the pulley 88. The lift motors 84 are driven
in opposite directions and in synchronism with each other
so as to advance the partitions 14 in the reserve stacks 72
up toward the guide rails 12. Thus, in the view shown in
Fig. 5, the left motor 84 rotates the paddles 74 in a
counter-clockwise direction while the right motor 84
rotates the paddles 74 in a clockwise direction. The
circumference of the pulley 88 is designed to equal the
distance between paddles 74 so that one full rotation of
the pulley 88 will advance the paddles 74 to the next
position.
The position of the paddles 74 may be sensed in ways
other than with the sensor 93 and the flag 95. For
instance, a flag may be affixed to one side of each bracket
98. As the paddles 74 are being rotated about the drive
unit 80, a proximity sensor would detect the flag on one of
the paddles 74 when the top paddle 74 becomes aligned with
the guide rails 12. The proximity sensor may be positioned
to detect the top paddle 74 or may be positioned to detect
the relative position of one of the other paddles 74.
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A block diagram of the partition feeder control system
100 is shown in Fig. 7. A programmable logic controller
(PLC) 102 controls the operations of the entire system 100.
In the preferred embodiment, the PLC 102 is an Allen-
Bradley Model No. PLC 5. It should be understood that the
invention is not limited to a PLC 102 but rather may be
embodied With other types of controllers.
The signals from the load cell_30 are processed by a
signal conditioner 104 and then supplied to the PLC 102 to
indicate the amount of force at the tabs 18. The signal
conditioner 104 converts the non-linear output of the load
cell 30 into a linear 4 to 20 mA signal. The signal
conditioner 104 could alternatively supply a linear 0 to l0
volt signal or an indexed signal to the PLC 102. The PLC
102 adjusts the speed and position of the pusher 26 based
upon the magnitude of the force at the tabs 18.
For instance, if a desired force at the tabs 18 is 3
lbs. and if the force at the tabs 18 is less than 1 lb.,
the PLC 102 advances the pusher 26 at a high speed toward
the tabs 18 to thereby increase the force. If the force is
above 1 lb. but below 2 lbs., the PLC 102 advances the
pusher 26 at a low speed toward the tabs 18. The PLC 102
stops the pusher 26 at a force of 3. lbs. , which is the
desired force at the tabs 18. When the force exceeds 4.5
lbs., the pusher 26 is moved away from the tabs 18 at a low
speed.
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While the invention is preferably used in conjunction
with the load cell 30 and related force sensing assembly,
the force at the tabs 18 may be controlled in other
manners. For instance, the stack of partitions 14 may
instead abut against a limit switch which informs the PLC
102 whether the first partition 14 is in position for a
pick. When the limit switch does not detect the end
partition, the PLC 102 advances the pusher 26 until the
partition 14 depresses a plunger in the limit switch.
l0 Other variations in the control of the pushers 26 will be
apparent to those skilled in the art.
The PLC 102 receives the position feedback from the
lift and pusher sensors 106. These sensors include the
first 51, second 52, and third 53 proximity sensors
relating to the position of the pusher 26, the sensors 107
indicating whether the pusher 26 is raised or lowered, the
photoeyes 56 on the pushers 26 for detecting partitions 14
from an approaching reserve stack 72, the photoeyes 76 on
the multi-rack assembly 70 for detecting the presence of
the lower two reserve stacks 72b and 72c of partitions 14,
and the proximity sensors 93 for detecting a full
revolution of the pulleys 88 in the drive units 80.
The PLC 102 is also connected to the various valves
and motors in the partition feeder 10. For instance,
through solenoid valves 108, pneumatic lines 103 and 105,
and pressure supplies 109, the PLC 102 controls rotary
actuators 40 for positioning the pushers 26 in either the
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raised or lowered position. To advance a reserve stack 72
of partitions 14 into alignment with the main stack, the
PLC 102 sends signals to relays for driving the left and
right synchronous lift motors 80. The PLC102 supplies
signals to the left and right stepper motors 42 through
respective drivers 112 for controlling the screw drives 38
and for thereby controlling the positions of the pushers 26
along the length of the feeder 10.
The PLC 102 executes a number of routines for
controlling the operations of the partition feeder l0.
While the PLC 102- repeatedly executes each of these
routines in a sequential fashion, the PLC 102 could instead
or additionally be programmed to have interrupts. Also,
although the PLC 102 is the preferred controller, the
operations of the partition feeder l0 could be controlled
by another type of device, such as a computer system.
A routine executed by the PLC 102 for controlling the
lift operation and initiating a pusher cycle is depicted in
a flow chart in Fig. 8. For the ease of description, the
positions of the three reserve stacks 72 will hereinafter
be referred to as levels 1 to 3, with level 1 being the
location of the uppermost reserve stack 72a and level 3
being the location of the lowermost reserve stack 72. In
this routine, at step 122 the PLC 102_ first determines
whether partitions 14 are present in level 1. If
partitions 14 are not present in level 1, the PLC 102
determines at step 124 whether all of the pushers 26 are
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clear. The pushers 26 are all clear when the pushers 26
are at the home position, which is at the far end of the
' partition feeder 10 opposite the tabs 18, or are past the
predetermined point along their travel toward the tabs 18.
With no partitions 14 in the level 1 and with all
pushers 26 clear, the multi-rack assembly 70 is permitted
to advance a reserve stack 72 up to level 1. Therefore,
the PLC 102 then checks at step 126 whether partitions 14
are present in level 2, and, if so, drives the lift motors
84 at step 128 to raise the partitions 14 up to level 1 and
the routine returns to start 120. If the partitions 14 are
not present in level 2 but are present in level 3, as
determined in step 130, the PLC 102 moves the partitions up
to level 2 at step 132 and the routine returns to start
120.
If partitions 14 are present in level 1, the PLC 102
waits at step 134 until either the left or right pusher 26
is at the home position. With one of the pushers 26 at
home and With partitions 14 present in level 1, the PLC 102
at step 136 adds the partitions 14 in level 1 to the main
stack with the at-home pusher 26. Once the feeding
operation for the partitions 14 in level 1 has begun, the
PLC 102 resets level 1 to empty at step 148 and the routine
returns to start 120.
A routine for controlling the operation of the feed
cycle for the left pusher 26 is shown in Fig. 9. The
operation of the right pusher 26 should be apparent from
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Fig. 9 and will therefore not be described in detail. With
reference to Fig. 9, the PLG 102 determines at step i42
whether a feeding operation with the left pusher 26 is
active and ends the routine at step 158 if it is not
active.
On the other hand, if the left pusher 26 feeding
operating is active, the PLC 102 next. determines at step 144
whether the feeding operation is also active for the right
pusher 26. If the right pusher 26 is not active, the left
pusher 26 is controlled at step 146 using the feedback from
the load cell 30 to maintain the force at the tabs 18 at an
optimal value or within a range of values . Reference may be
made to commonly-assigned U.S. Patent No. 5,585,568 for a
full description of a routine executed by the PLC 102 for
controlling the pusher 26. The left pusher 26 is controlled
by the load cell 30 until, at step I48, a homing operation
is active for the left pusher 26, at which time the left
pusher 26 returns to the home position and the routine ends
at step 158.
Tf the right pusher 26 is already active, at step 150
the PLC 102 advances the left pusher 26 at a high speed
toward the right pusher 26 in order to close the gap
between the two pushers 26. Once the gap has been closed,
as determined at step 152, the photoeye 56 on the right
pusher 26 will detect the approach of the partitions 14
advanced by the Left pusher 26, control of the right pusher
26 will be deactivated at step 154, and the right pusher 26
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will be sent to the home position at step 156. With the
right pusher 26 removed and the left pusher 26 advancing
the stack, the routine returns to the step 142 of checking
whether the feeding operation is active for the left pusher
26.
With reference to Fig. 10, the partition feeder 10 has
three nested frames 162, 164, and 166 for supporting and
mounting the partition feeder to at a specific location
relative to a flow of articles. The majority of the
l0 elements constituting the partition feeder 10 are mounted
to the middle frame 164 with only the guide rails 12 being
mounted to the inner frame 166. The middle frame 164 is
mounted to the outer frame 162 in manner that allows the
vertical adjustment of the partition feeder 10 while the
inner frame 166 is mounted to the middle frame 164 in a
manner that allows the horizontal adjustment of the
partition feeder 10.
More specifically, with regard to the vertical
adjustment, each side of the partition feeder 10 has a bolt
170 threaded through a bracket 172 integral with the middle
frame 164. An upper end of each bolt 170 is connected to
a sprocket 174, which is securely mounted to the outer
frame 162. The sprockets 174 are interconnected with a
chain 176 so that both bolts 170 will be rotated whenever
one of the bolts 170 is rotated. When a knob 178 geared to
a lower end of one bolt 170 is rotated, the bolt 170
rotates and causes the bracket 172 to either move up or
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down along the length of the bolt 170. Thus, depending
upon the direction in which the knob 178 is rotated, the
bracket 172 and the entire middle frame 164 can be raised
or lowered with respect to the outer frame 162.
With regard to the horizontal adjustment of the
partition feeder l0, the inner frame 166 is comprised of a
pair of vertical plates which are formed between two walls
180 of the middle frame 164. The walls 180 of the middle
frame 164 are joined together by two support rods 182 and
a bolt 186 which extend through each of the plates 166.
The plates 166 are mounted to the support rods 182 through
bearings 188 to allow the plates 166 to slide along the
support rods 182 and are mounted to the bolt 186 through
nuts 190 integral with the plates 166. The two ends of the
bolt 186 are threaded in opposite directions so that the
rotation of the bolt 186 will cause the plates 166 to move
in opposite directions, that is either toward or away from
each other. A knob 192 is attached to one end of the bolt
186 to allow an operator to adjust the distance between the
plates 166 by rotating the knob 192.
The partition feeder 10 can be easily adjusted for
partitions 14 of various sizes. By rotating the knob 192,
the distance between the plates 166, and thus the distance
between the guide rails 12, can be adjusted to correspond
with the widths of the partitions 14. The stack of
partitions 14 can then be adjusted vertically with knob 178
to adjust the partition feeder 10 to the height of the
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partitions 14. These adjustments are easily performed by
simply rotating the.knobs 178 and 192 and do not require an
operator to replace any parts in the partition feeder 10.
since the partition feeder 10 can be adjusted for
partitions of different sizes, the partition feeder 10 is
not limited to a specific packaging machine but rather can
be used to package articles having various sizes and
configurations into cartons of different sizes.
It should be understood that the invention is not
l0 limited to the partition feeder 10 shown in the figures.
For instance, the multi-rack assembly 70 can be designed to
hold a greater or lesser number of stacks 72, such as only
one reserve stack or four or more reserve stacks. Also,
the multi-rack assembly 70 could add a reserve stack 72 of
partitions 14 or cartons into a supply hopper when the main
stack in the supply hopper has been reduced down to a
certain point.
The size and shape of the guide rails 12 may be varied
to the particular size and shape of a partition 14. Thus,
if the partitions 14 do not have notched sides but instead
have another shape of indentation or aperture, the guide
rails 12 can be modified to mate with the other indentation
or aperture in order to suspend the partitions 14.
Further, the partition feeder 10 may be adjusted in
ways other than that shown. For example, the partition
feeder 10 may be constructed to have a greater or lesser
number of frames which permit the vertical and horizontal
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adjustment of the guide rails 12. While the adjustments
have been described as being performed manually, the
adjustments could easily be performed automatically through
suitable motors and sensors. Thus, an operator could press
a button or otherwise indicate to the PLC 102 that the
partition feeder. l0 needs to change from one partition size
to another partition size and all of the requisite
adjustments would be controlled through the PLC 102.
It will further be obvious to those skilled in the art
that many variations may be made in the above embodiments,
here chosen for the purpose of illustrating the present
invention, and full result may be had to the doctrine of
equivalents without departing from the scope of the present
invention, as defined by the appended claims.
