Note: Descriptions are shown in the official language in which they were submitted.
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APPARATUS FOR CONTROLLING THE FLOW OF ARTICLES
This application is a divisional application of
co-pending application 2,356,393, filed June 22, 2001.
Background of the Invention
The present invention relates to an apparatus for
controlling the flow of articles from an upstream delivery
station to a downstream receiving station; and more
particularly to an apparatus wherein articles can be
accumulated between an upstream delivery station and a
downstream receiving station, and fed to the downstream
receiving station in a first in first out (FIFO) sequence.
Heretofore, accumulators have been utilized between an
upstream delivery station and a downstream receiving station
to accumulate articles when the capacity of the downstream
receiving station is either shut down or run at a speed
wherein it cannot handle the number of articles being fed by
the upstream delivery station. One particular accumulator
is disclosed in US Patent 4,018,325. One problem with such
accumulators is that the last article fed into the
accumulator is the first article fed out of the accumulator
and, as a result, it is difficult to keep track of the batch
from which a particular article came from, and the sequence
in which the articles are fed from the upstream delivery
station.
Attempts have been made to produce accumulators wherein
the first in is the first out article as disclosed in US
Patent 4,513,858.
The present invention is particularly adapted for use
wherein an upstream delivery station may be a filling
station for placing contents into a package and feeding them
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to a downstream receiving station wherein the package is
placed in boxes. It of course can be used in many different
industries wherein there is a need to control the rate of
flow of articles between an upstream delivery station and a
downstream receiving station.
Summary of the Invention
One of the objects of the present invention is to
provide an apparatus for controlling the flow of articles
from an upstream delivery station to a downstream receiving
station and for temporarily storing the articles there
between and feeding the first article stored therein out
first (FIFO) in a controlled flow to minimize damage from
pressure or wear not only inside, but on entry and at next
machine.
Another important object of the present invention is to
provide an apparatus for accumulating articles wherein there
is a minimum of contact between the articles in the
accumulator. This minimizes damage to labels and printed
material carried on the outside of the article or package or
to the article itself.
Still another important object of the present invention
is to provide an article storage accumulator which permits a
large number of articles to be stored in a relatively small
amount of floor space, thus reducing the distance between an
upstream delivery station and a downstream receiving
station.
Still another object of the present invention is to
provide an accumulator which operates automatically
responsive to the requirements of a downstream receiving
station to store articles temporarily prior to delivering
the articles to the downstream receiving station in a first
in first out (FIFO) sequence.
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It is another object of the present invention to
decrease the potential for damage or breakage as well as
jamming or wedging of items to be accumulated because of the
manner in which the articles are stored on a moving
conveyor.
It is another important object of the present invention
to provide an effective and reliable accumulator which can
be readily modified for accumulating articles of different
sizes and configurations.
Still another important object of the present invention
is to provide an apparatus for accumulating articles in a
vertically stacked arrangement on a moving conveyor system
constructed in the form of a vertically extending spiral.
Still another important object of the present invention
is to provide an accumulator wherein articles are
temporarily stored on a moving conveyor which permits the
loading and unloading of the moving conveyor responsive to
the capacity of a downstream receiving station.
Another important object of the present invention is to
provide an accumulator which utilizes an infeed and outfeed
conveyor for temporarily storing articles at a rate
depending on the relative speed of travel of the infeed
conveyor and the outfeed conveyor.
Another object of the present invention is to provide
an effective and reliable apparatus for controlling the flow
of articles from an upstream delivery station to an
downstream receiving station at a relatively high speed.
Another object also is to make a more responsive
apparatus thereby minimizing the need for additional
conveyors.
The above objects are accomplished by an apparatus that
controls the flow of articles being transported on a main
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conveyor from an upstream delivery station to a downstream
receiving station according to the capacity of the
downstream receiving station. The apparatus includes an
endless infeed conveyor and endless outfeed conveyor. A
support structure supports the infeed conveyor and the
outfeed conveyor where a substantial portion of the run of
the conveyors are parallel to each other providing a space
therebetween. A track is carried by the support structure.
The track extends along the parallel run of the infeed and
outfeed conveyors. A transport member is carried by the
track in the space provided between the infeed and outfeed
conveyors for movement along the length of the infeed and
outfeed conveyors.
An infeed drive mechanism drives the infeed conveyor in
one direction, and an outfeed drive mechanism drives the
outfeed conveyor in a second direction. A deflective plate
or any other suitable mechanism is used for transferring the
articles from a main conveyor onto the infeed conveyor. A
rotatable member is carried by the transport member. There
is a driving coupling provided between the infeed conveyor
and the rotatable member through which the infeed conveyor
rotates the rotatable member. There is also a driving
coupling provided between the rotatable member and the
outfeed conveyor for rotating the rotatable member and
causing the transport member to move along the guide track
in a direction depending upon the relative speed of travel
of the infeed and outfeed conveyors. An article transfer
member is carried by the transport member for transferring
articles from the infeed conveyor to a position along the
outfeed conveyor as the transport member moves along the
guide track.
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The accomplishment of the objects discussed above will
become readily apparent from the following description of
various embodiments of the present invention.
Brief Description of the Drawings
Figure 1 is a plan view illustrating an apparatus for
controlling the flow of articles in its basic forms.
Figure 2 is a plan view of the apparatus of Fig. 1
showing articles being loaded into the apparatus.
Figure 3 is a plan view of a modified form of the
invention.
Figure 4 is a schematic diagram illustrating an
apparatus storing articles in a vertical spiral.
Figure 5 is a plan view, partially in section,
illustrating infeed and outfeed conveyors as well as a
transport member forming part of the invention.
Figure 6 is a plan view illustrating the transport
member going around a curved portion of the track.
Figure 7 is a plan view illustrating a linkage
mechanism for controlling the movement of the wheels of the
transport member.
Figure 8 is a cross-sectional view illustrating a track
for supporting the outfeed conveyor and an article being
transported thereon.
Figure 9 is a sectional view taken along line 9-9 of
Fig. 8 illustrating a rotatable member forming part of a
transport member and drivers carried on the conveyors.
Figure 10 is a schematic diagram illustrating the
manner in which the transport member is moved between an
infeed and outfeed conveyor.
Figure 11 is an exploded view of a transport member.
Figure 12 is a cross-sectional view of the transfer
member.
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Figure 13 is a schematic representation of a modified
form of the transport member.
Figure 14 is a perspective view illustrating a modified
form of the drive mechanism for the transport member.
Figure 15 is a plan view illustrating in schematic form
a modified form of a deflecting member (drive position) used
with the transport member.
Figure 16 is a perspective view illustrating a modified
form of a drive mechanism for the transport member.
Figure 17 illustrates in partial schematic form the
driving connection for driving the infeed and outfeed
conveyors when carried in a spiral configuration.
Figure 18 is a perspective view illustrating the
driving mechanism for driving a conveyor belt of a modified
conf igurat ion .
Figure 19 is a plan view illustrating a modified form
of the main conveyor.
Figure 20 is a plan view illustrating a modified form
of the main conveyor and the mechanism for deflecting the
articles off the main conveyor and for receiving the
articles back on the main conveyor.
Figure 21 is a plan view illustrating in schematic form
a modified form of the transport member.
Figure 22 is a plan view illustrating in schematic form
a modified form of a transfer member forming part of the
invention.
Figure 23 is a partial schematic view of an alternate
preferred drive mechanism arrangement for the infeed and
outfeed conveyors.
Figure 24 is a partial plan view of an alternative
embodiment of the article transfer member according to the
invention.
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Figure 25 is a perspective partial cutaway view of the
embodiment of the article transfer member illustrated in
Figure 24.
Figure 26 is a perspective view of the alignment rail
mechanism illustrated in Figure 24.
Figure 27 is a alternative perspective view of the
alignment rail mechanism taken along the lines indicated in
Figure 26.
Detailed Description of the Preferred Embodiments
Referring to Figs. 1, 2, 3 and 4 there is illustrated
an apparatus for controlling the flow of articles 10 from an
upstream delivery station (Fig. 4) to a downstream receiving
station. The articles are being carried on a main conveyor
12 that is driven by any conventional conveyor drive
mechanism for transporting the articles 10 from the upstream
delivery station. The articles are feed along the main feed
conveyor 12 until they reach a deflecting rail 14 wherein
they are deflected off of the main conveyor 12 onto an
infeed conveyor A. The infeed conveyor A is an endless
conveyor and is driven by a variable speed motor 16.
An outfeed conveyor B is carried on a support
structure. Only the vertical posts 18 are being shown for
purposes of clarity. A substantial portion of the run of
the infeed and outfeed conveyors A and B are parallel to
each other providing a space 20 therebetween.
A transport member D rides on a track carried by the
support structure that permits the transport member D to
move backwards and forwards along the length of the infeed
and outfeed conveyors A and B. The infeed drive mechanism
16 drives the infeed conveyor A in a first direction. An
outfeed drive mechanism 22 drives the outfeed conveyor B in
a second direction. A variable speed control 24 is
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operatively connected to the outfeed drive mechanism for
varying the speed of the outfeed conveyor.
A rotatable member E see Figs. 10 and 11 is carried by
the transport member D. Drivers F are carried by the infeed
conveyor A and engaged the rotatable member E for rotating
the rotatable member. Drivers G are carried by the outfeed
conveyor B and engage the rotatable member E for rotating
the rotatable member and causing said transport member D to
move along a path parallel to the infeed conveyor A and the
outfeed conveyor B, at a speed and direction depending on
the relative speed of the infeed conveyor A and the outfeed
conveyor B. An article transfer member H is carried by the
transport member D for deflecting articles from the infeed
conveyor A to the outfeed conveyor B.
The speed of the outfeed conveyor is controlled by the
variable speed motor 22; and if the speed of the outfeed
conveyor B is running slower than the speed of the infeed
conveyor A then the transport member as shown in Figs. 1, 2
and 3 is moved in the counter clockwise direction loading up
the articles on the surfaces of the infeed conveyor and the
outfeed conveyor B for temporarily storing the articles in
the accumulator.
When the demand from the downstream receiving station
increases, a signal is generated by condition responsive
devices 32 and 34 positioned along side of the conveyor B
and on conveyor 12. These devices will cause the speed of
the outfeed conveyor B to increase and be greater than the
speed of the infeed conveyor. When this occurs, the
transport member D due to the driving connection between the
infeed and outfeed conveyors A and B will move in a
clockwise direction; and the number of articles stored on
the infeed and outfeed conveyors A and B will be reduced and
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the first article that was stored is the first article
delivered from the outfeed conveyor B. The driving
connection between the transport member D and the infeed and
outfeed conveyor A and B will be discussed in greater detail
below.
Condition responsive devices are positioned along the
conveyors for generating signals responsive to various
conditions. For example, condition responsive device 26 is
positioned adjacent to the main conveyor 12 for sensing a
backup of articles on the main conveyor; and if such a
condition occurs a signal is sent to a controller which
causes the infeed conveyor A to shift to a higher speed.
The condition responsive device 26 may be any suitable
conventional sensor, but in one particular embodiment it is
a photocell provided with a timer so that if the photocell
is activated for a certain period of time by non movement of
the article a signal is generated. The articles 10 carried
on the main conveyor are spaced apart, and as long as the
space is sensed between the articles in a given period of
time then no signal is generated by the photocell to trigger
an increase in speed of the infeed conveyor A. One suitable
photocell is manufactured by Sick A.G. having a part number
of WT4-2P135S10. Sick A.G. is located in Wldkirch, Germany.
It is to be understood that any conventional suitable
conditional responsive device could be used at any of the
locations where one is required.
Another condition responsive device 28 is positioned
along the main conveyor closely adjacent to the front end of
the rail 14. It is provided to sense a backup on the
conveyor, and causes a signal to be produced to reduce the
speed of the conveyor to a medium speed. Another
conditional responsive device 30 is positioned near the
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entrance of the infeed conveyor A for sensing a lack of
products or articles on the infeed conveyor A and this
sensor stops the infeed conveyor when such a condition
occurs.
There is still another condition responsive device 32,
positioned adjacent to main conveyor 12, where the articles
are fed back onto the main conveyor. When a backup of
articles is sensed by condition responsive device 32 on the
main conveyor 12, such stops the outfeed conveyor B. A
backup is sensed when the articles exiting off of the
outfeed conveyor B are pressed against each other on the
main conveyor 12.
Under normal operation the main conveyor 12 is running
at a higher speed than the outfeed conveyor B, and as the
articles are transferred from the outfeed conveyor B onto
the main conveyor 12 a space is developed between the
articles. The condition responsive device 32 is provided
for ensuring that this space remains between the articles,
and if the space is lost as a result of a backup of articles
then the outfeed conveyor B is stopped. A still further
condition responsive device 34 is positioned further down
the line on the main conveyor, and when it senses that there
is no space between the articles being delivered back onto
the main conveyor a signal is generated, which is feed to
the variable speed motor 22 driving the outfeed conveyor B,
for reducing the speed of the variable speed motor 22. All
of the signals generated by the conditional responsive
devices are feed through conventional controllers such as
programmable logic controller, which in turn is used for
controlling the drive speed of the infeed drive motor 16,
and the outfeed drive motor 22. One suitable programmable
logical controller is manufactured by Allen Bradley and has
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a model number of SLC500 series. Allen Bradley is located
in Milwaukee, Wisconsin.
In order for the transport member D to move from the
position shown in Fig. 2 to the position shown in Fig. 1 the
speed of the infeed conveyor A must be running faster than
the speed of the outfeed conveyor B. As a result, when the
transport member D is moved in a counter clockwise direction
it is loading articles from the infeed conveyor A to the
outfeed conveyor B for storing the articles. As previously
mentioned when the demand at the downstream receiving
station increases then the speed of the outfeed conveyor B
will increase over the speed of the infeed conveyor A; and
due to the coupling provided between the infeed and outfeed
conveyors and the transport member D, the transport member D
will move in a clockwise direction from the position shown
in Fig. 1 to the position shown in Fig. 2 to unload the
articles stored in the accumulator.
The configuration for the parallel run of the infeed
conveyor A and the outfeed conveyor B can vary depending on
the amount of floor space that is desired to be utilized for
the accumulator. In Figs. 1 and 2 the configuration of the
infeed and outfeed conveyors is in a spiral. In Fig. 3 the
configuration of the infeed conveyor A and the outfeed
conveyor B is also in a spiral but it has an elongated
middle portion. If there is sufficient floor space the run
of the two conveyors A and B can be in a horizontal plane.
As shown in Fig. 4 the configuration of the infeed
conveyor A and the outfeed conveyor B is in a vertical
spiral so that a substantial amount of storage can be placed
in a relatively small space. Sometimes as the height of the
spiral increases it is necessary to drive the infeed and
outfeed conveyors along the vertical path of the spiral so
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as to minimize the drag of the conveyors on the track. The
drive mechanism is shown in schematic form in Fig. 4 and
will be described in greater detail in connection with Fig.
13.
As can be seen in Fig. 4 the infeed conveyor A and the
outfeed conveyor B are endless conveyors. The infeed
conveyor A is driven by a motor 16, and its path extends
upwards from adjacent the main conveyor 12 in a spiral
configuration to pass over a drive sprocket 36 then down a
vertical run through an idle sprocket 38 and back to the
track which holds the conveyor in a vertical spiral. The
track for holding the conveyor may be of any suitable
construction and is supported on vertical posts 18 and
cross bracing (not shown for purpose of clarity). The
outfeed conveyor B is driven by the outfeed drive motor 22
by means of a drive sprocket 40. The conveyor belt B passes
around idle sprockets 42 and 44 in its run.
The infeed conveyor A and the outfeed conveyor B may be
constructed of any suitable conventional chain belt that has
connecting links, and in one particular embodiment has an
upper surface such as shown in Figs. 5 and 6. The lower
surface has driving lugs 46 provided thereon which engage
teeth provided on a sprocket carried by an output shaft of
the infeed drive motor 16. The outfeed conveyor B engages
teeth carried on a sprocket provided on an output shaft of
the outfeed drive motor 22.
The driving links 50 have grooves provided so that the
conveyor belts A and B can ride on the track 58 and 60. The
track is defined by two elongated space strips 62 and 64
such as shown in Fig. 9. Drivers F in the form of posts 48
are carried on the lower surface of each of the links 50 of
the infeed conveyor A. Similar drivers G in the form of
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posts 52 are provided on the lower surface of each of the
links 54 of the outfeed conveyor B. The posts 48 and 52
extend downwardly from the links 50 and 54 respectively, for
engaging teeth 61 provided in the rotatable member E. As
shown in Fig. 10 if the infeed conveyor A is moving to the
right at a higher rate of speed than the outfeed conveyor B
is moving to the left the posts 48 and 52, engaging the
teeth 61 of the rotatable member E will cause the rotatable
member E to rotate and also move to the right. For example
the phantom line position drawn therein. If however, the
outfeed conveyor B is moving to the left at a faster rate of
speed than the infeed conveyor is moving to the right, then
the rotatable member will be shifted to the left as it is
rotated.
The rotatable member E is carried on a transport member
D shown in an exploded view in Fig. 11. The transport
member D includes a pair of elongated plates 68 and 70. The
plates are substantially rectangular in shape and have
curved inner ends 72 and 74 respectively provided thereon.
A post 76 projects upwardly from the inner end of the plate
70 and extends through an opening 78 provided adjacent the
inner end of plate 68. An arcuately shaped rectangular
guide bar 80 is carried on the upper surface of the plate 70
that fits within a groove 82 provided in a lower surface of
a dead plate 84. The dead plate is permitted to shift
laterally slightly during the travel of the transport member
around curves.
A set of wheels 86 are carried on a horizontally
extending bar 88 carried adjacent to an outer end of the
support plate 70. The horizontally extending bar 88 is
pivotally attached to the support plate by a pivot pin 90.
The wheels 86 are connected to upwardly extending flanges 86
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carried on the horizontal member 88 so as to permit them to
rotate freely thereon. A similar set of wheels 92 are
carried on the outer ends of the plate 68 and are supported
on vertically extending flanges 94 connected to opposite
ends of the horizontal bar 96. The bar 96, in turn, is
pivotally connected by means of a pivot post 98 to the plate
68. As a result, the wheels 86 and 92 can pivot about the
pivot points 90 and 98 respectively, as the transport member
moves around the curves included in the spiral track.
In order to stabilize the pivotal movement of the
wheels and assist them in following the curvature of the
track, connecting linkages 102 and 104 are pivotally
connected to pivot posts 106 and 108, provided on the
horizontal bars 88 and 96. The linkage arms 102 and 104
have downwardly extending posts 106 and 108 respectively,
carried on the inner ends thereof, which project down within
slots 110 and 112, provided in a circular plate 114. The
circular plate is carried on the post 76. As a result of
the linkage arms 102 and 104 when the transport member goes
around a curved portion of the track, the wheels 86 and 92
follow the curvature of the track. The linkage arm 102 and
104 control the movement of the sets of wheels 86 and 92.
As previously discussed the rotatable member E is
carried on the post 76, and has four circumferentially
spaced, vertically extending pins 116, provided on an upper
surface thereof. These pins 116 are provided for securing a
guide wheel 118 on top of the rotatable member E. As a
result of the pins 116 extending through bores 120 provided
in the wheel, the wheel 118 is rotated with the rotatable
member E.
An article transfer member H is carried by the
transport member D and has a curvature similar to that of
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the curvature of a horseshoe. This is defined by a pair of
spaced end portions 122 and 124 which are joined by an
arcuately shaped intermediate portion 126 (see Fig. 11).
The end portions 122 and 124 extend over the infeed conveyor
A and the outfeed conveyor B respectively, as shown in Figs.
1 through 3. The guide plate is spaced from the rim of the
wheel 118, so as to define a path through which the articles
10 are guided as they are shifted from the infeed conveyor A
to the outfeed conveyor B. Different sized and shaped
wheels 118 can be placed on the pins 116 for varying the
size of the path extending between the rim 119 of the wheel
118 and the inner surface of the guide plate H, and for
transferring articles of different sizes and configurations.
In Fig. 7 the dead plate 130 over which the articles
pass as they are moved from the infeed conveyor A to the
outfeed conveyor B is shown as a flat plate 130 that has an
inner edge 132 which terminates adjacent the edge of the
infeed conveyor A, and has an opposing edge 134 which
terminates closely adjacent the edge of the outfeed conveyor
B. The plate 130 is carried by the transport member D. In
the embodiment shown in Fig. 11 the dead plate is allowed to
move slightly in the lateral direction on the rail 80.
Referring back to Fig. 7 there is shown how the plates
68 and 70 pivot about the posts 76, as the transport member
D moves around the curves provided in the guide track so as
to follow the guide track accurately. The movement of the
plates 68 and 70 is shown in phantom lines in Fig. 7.
Referring to Fig. 8 of the drawings, the details of the
track upon which the conveyor B is supported is illustrated.
The track includes a pair of spaced plates 58 and 60. The
plates 58 and 60 are in turn supported on a suitable support
structure that holds them in a fixed relation; and the
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plates 58 and 60 define the track which guides the conveyor
in the configuration, such as the spiral configuration shown
in Fig. 4. The plate 58 has a bearing block 140 fixed on
the inner end which is there to provide a frictionless
surface upon which the links of conveyor B run. The plate
60 also has a "U" shaped bearing block 142 secured to the
inner end thereof for supporting the links of conveyor B.
As can be seen, the links of the conveyor include a
horizontally extending upper surface 144, which have a pair
of downwardly extending space flanges 146 and 148 extending
from a lower surface thereof. These flanges 146 and 148
have inwardly extending horizontal flanges 150 and 152
carried on a lower surface thereof, so as to define a groove
into which the frictionless bearing blocks 140 and 148 ride
when supporting the links of conveyor B. The same linkage
is provided on the infeed conveyor A as illustrated on the
outfeed conveyor B in Fig. 8.
The tracks 58 and 60 are supported by any suitable
cross frames supported on the vertically extending posts 18,
and can be supported to define any desired configuration for
the infeed and outfeed conveyors A and B, as shown in Figs.
1 - 4.
In Fig. 16 there is illustrated a modified form of the
invention, and in particular the drive mechanism for the
rotatable member E. The infeed conveyor A and the outfeed
conveyor B have space slots 154 and 156 provided in the
surface thereof, into which the teeth of sprockets 158 and
160 mesh. As a result, when the conveyors A and B are
moving a driving rotational movement is imparted through the
sprockets 158 and 160 to a differential gear arrangement 162
for driving a chain 164. The chain 164 is carried on a
sprocket 166 which is secured to a shaft 168 forming part of
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the differential gear arrangement 162. The chain 164
extends around another sprocket 170 provided on the post 76
for rotating a rotatable member F. A wheel 118 can be
placed on top of the rotating member E shown in Fig. 16 in
the same manner as illustrated in Fig. 11. The purpose of
Fig. 16 is to show a modified drive mechanism for rotating
the rotatable member E.
In Fig. 15 there is illustrated another modified form
of the invention wherein instead of using the arcuately
shaped deflection plate H, such as shown in Figs. 11, an
arcuately shaped movable belt is driven by posts 172 and 174
extending downwardly from the lower surface of the infeed
conveyor belt A and outfeed conveyor belt B. The post 172
and 174 engage teeth 176 and 178 respectively carried on
sprockets 180 and 182. The sprockets 180 and 182 are in
turn rotatably supported on shafts 184 and 186 that are
carried on a lower service of the transport member. A
moveable belt 185 extends around the sprockets 180 and 182,
and is carried in a curved configuration defined by any
suitable arrangement of idle roles not shown. The belt 185
is driven by the infeed and outfeed conveyors A and B
providing a moving surface for the articles being
transferred from the infeed conveyor to the outfeed
conveyor. The details of the transport member are not
illustrated in Fig. 15 for purposes of clarity. The moving
belt 185, in conjunction with the wheel 118, transports the
articles 10 from the infeed conveyor A to the outfeed
conveyor B, by providing two moving surfaces which engage
opposite sides of the articles 10.
Referring now in more details to Fig. 13. Instead of
the transport member D having a dead plate 84 over which the
articles 10 are transported from the infeed conveyor A to
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the outfeed conveyor B, a moveable belt 190 is carried by
the transport member D, and is supported for rotation on
idle wheels 192 and 194. The moveable belt 190, has posts
196 provided on a lower surface thereof, which engage the
teeth 61 of the rotatable member E. The belt 190 is driven
by the rotatable member E for aiding in transporting the
articles 10 from the infeed conveyor A to the outfeed
conveyor B.
Instead of using a single gear toothed rotatable member
E, such as shown in Fig. 13, the drive mechanism for the
wheel 118 that is carried on the transport member can be a
chain drive, such as illustrated in Fig. 14. In Fig. 14,
two sprockets 198 and 200 are carried on a plate forming
part of the moveable member. A chain 202 extends around two
driven sprockets 201 and 203, which are rotated by the
shafts 205 and 207 that the sprockets 198 and 200 are fixed
to. The sprockets 198 and 200 are rotated as the sprockets
engage the posts 48 and 52 carried on the lower surface of
the infeed and outfeed conveyors A and B respectively. The
chain 202 extends around a sprocket 204 that in turn is
rotated around posts 206. The chain 202 and sprocket
arrangement shown in Fig. 4 performs the same function as
the rotatable gear E shown in Fig. 11. The remaining
structure, such as the rotatable wheel 118 and guide plate
H, could be the same as the structure included in the
transport member D of Fig. 11.
When the configuration of the infeed and outfeed
conveyors A and B extends vertically upwardly in several
layers, such as shown in Fig. 4, it is desirable that each
layer of the conveyor is driven from the infeed drive motor
16 and the outfeed drive motor 22. This overcomes the drag
produced by the long run of the conveyor chains A and B. In
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Fig. 17, there is illustrated a drive mechanism for such a
spiral configuration . The various layers of the infeed and
outfeed conveys A and B are shown stacked one upon the other
in Figs. 4 and 17. The infeed motor 16 is connected through
a gear box 210 which has output drive shafts 212 and 214
extending outwardly therefore. The output drive shaft 212
is connected to a gear box 216 which is connected to a
vertically extending shaft 218. The vertically extending
shaft 218 has gear boxes 220, 222 and 224 spaced therealong,
so that there is a drive connection from the motor 16 to
each of the gear boxes 220, 222 and 224. Each of the gear
boxes 220, 222 and 224 have an output shaft 226 which drives
a driving gear 228 that is a driving engagement with the
infeed conveyor A. An idle gear 230 is provided on the
outer end of the shafts 226 that engage the outfeed conveyor
B. The output shaft 214 of the gearbox 210 is connected to
a gear box 236 which in turn drives a vertically extending
shaft 238. The vertically extending shaft 238 has gear
boxes 240, 242 and 244 spaced vertically therealong. Gear
boxes 240, 242 and 244 have output shafts 246, 248 and 250
respectively. Each of these shafts, 246, 248 and 250 have
driving gears 252 provided thereon, which engage the lugs of
the infeed conveyor A for driving the various layers of the
infeed conveyor A. Idle gears 254 are carried on the end of
the shafts 246, 248 and 250 for engaging the outfeed
conveyor B.
The outfeed conveyor B is driven by the variable speed
motor 22 through a gear box 256. The gear box 256 in turn
is used for driving vertically extending shafts 258 and 260.
The vertically extending shafts 258 and 260 have gear boxes
262 provided along the length thereof. Each of the gear
boxes 262 have an output shaft 264 extending therefrom for
CA 02493548 1999-10-27
driving a sprocket 266 which engages the outfeed conveyor B.
An idle sprocket 268 engages the infeed conveyor A. Chains
270 and 272 extend between the driven sprocket 266 and the
idle sprocket 230 such as shown on the top left, and the
driven sprocket 228 as well as the idle sprocket 268. The
chains extending around a driven sprocket and an idle
sprocket aids, in stabilizing the driving force imparted to
the conveyor belts A and B.
The condition responsive devices 26, 28, 30, 32 and 34
(Fig. 1) sense the various flow of articles on the
conveyors, such as described above in connection with Fig.
1, and send signals to a PLC which is used for varying the
speed of the outfeed motor 22. As previously mentioned, the
speed of the main conveyor 12 can be stopped. Also, the
speed of the infeed conveyor A and outfeed conveyor B can be
stopped depending on the flow of articles through the
accumulator as described previously.
In Figs. 19 and 20 there are illustrated two different
arrangements for the main conveyor 12 which transports the
articles 10 from the upstream station to the downstream
station. In the embodiment illustrated in Fig. 19, the main
conveyor includes two conveyors 12a and 12b. The articles
being transported on the main conveyor 12a are deflected
onto the infeed conveyor A by means of an angled deflecting
rail 300. The articles coming off the outfeed conveyor B
are guided onto the main conveyor 12b by the spaced guide
rails 302 and 304.
In Fig. 20 instead of using two main conveyors 12a and
12b a single main conveyor 12 is utilized. When it is
desired to deflect the articles from the main conveyor 12 to
the infeed conveyor A, a deflecting guide rail 306 is moved
by a pneumatic or hydraulic cylinder 308 from the full line
CA 02493548 1999-10-27
21
position to the phantom line position. When the guide rail
is moved to the full line position the accumulating function
is taken out of service, and the articles are moved directly
along the main conveyor. A similar deflecting plate 310 is
associated with the outfeed conveyor B, and when it is
desired that the articles be allowed to flow directly from
the upstream delivery station to the downstream receiving
station without going through the accumulator, the
deflecting plate 310 is moved to the full line position.
However, when the accumulator is in use, the deflecting
plate is moved to the phantom line position by means of a
pneumatic or hydraulic cylinder 312.
Summary of the Operation
Attention is directed to Fig. 2 of the drawings. As
can be seen in Fig. 2, articles 10 are feed on the main
conveyor 12 onto an infeed conveyor A which is an endless
conveyor belt. The articles are then moved on the infeed
conveyor A up and around the infeed conveyor A until they
engage a deflecting plate H carried on a transport member D.
The deflecting plate H deflects the articles over the
movable transport member D from out the infeed conveyor A to
the outfeed conveyer B. If the speed of the outfeed
conveyor B is the same as the speed of the infeed conveyor
A, then the articles merely moved over the dead plate 84 of
the transport member D to the outfeed conveyor B, and are
fed back onto the main conveyor 12. However, if for example
there is no demand for articles from the downstream
receiving station, and as a result the outfeed conveyor is
stopped, the transport member D will move in a counter
clockwise direction around the spiral causing the articles
being feed in on the infeed conveyor A to be lined up on the
outfeed conveyor B. This action continues until the
CA 02493548 1999-10-27
22
transport member D reaches the top of the spiral, wherein it
engages a limit switch that stops the entire accumulation
system.
If, however, prior to reaching the top of the spiral
the downstream receiving station begins taking articles from
the main conveyor 12 a signal is generated, by the condition
responsive devices 32 and 34, turning on the motor 22
driving the outfeed conveyor B. The outfeed conveyor B
begins running faster than the infeed conveyor A, and as a
result, the articles are transferred in sequence from the
outfeed conveyor B back onto the main conveyor 12. The
incoming articles 10 that are being feed on the infeed
conveyor A are continuously loaded on the outfeed conveyor
but, as a result of the transport member moving in a
clockwise direction, the number of articles in the
accumulator decreases until the accumulator is entirely
empty. When the transport member reaches the bottom of the
spiral it engages another limit switch which stops the
transport member from any further movement.
The movement of the transport member D is controlled by
the speed of the infeed and outfeed conveyors A and B.
Referring now to Fig. 10, the infeed conveyor A and the
outfeed conveyor B have posts 48 and 52 provided thereon
which engage the teeth of a rotatable member E. If the
speed of the infeed conveyor A is the same as the speed of
the outfeed conveyor B then the transport member D, which
carries a rotatable member E, remains in the same position.
However, if the outfeed conveyor B slows down relative to
the infeed conveyor, the moveable member will be moved to
the right as illustrated in Fig. 10, and the articles are
loaded along the outfeed conveyor B until the speed of the
CA 02493548 1999-10-27
23
outfeed conveyor B is increased to deliver more articles to
the downstream receiving station.
when the speed of the outfeed conveyor increases above
the infeed conveyor A, such causes the transport member to
rotate rotatable member E to move to the left and unload the
accumulator.
One advantage of this accumulator is that the first
article in is the first article out (FIFO), and as a result
the sequence from which the articles are fed from the
upstream delivery station is always maintained.
When the articles are fed from the upstream delivery
station there is normally a space between the articles. The
speed of the infeed conveyor A is slower than the speed of
the main conveyor 12, and as a result when the articles 10
are transferred from the main conveyor 12 onto the infeed
conveyor A, they are positioned close to each other with
very little space therebetween. When the articles 10 return
to the main conveyor 12 from the outfeed conveyor a space is
produced between the articles.
Since the articles do not move relative to the surface
of the conveyors A and B, there is very little rubbing
between the articles as they are being stored and removed
from the accumulator. This minimizes any damage or scraping
of the labels carried on the articles.
The condition responsive devices 26, 28, 30, 32 and 34
control the speed of the conveyors through a programmable
logic controller. If, for example, the downstream receiving
station stops receiving articles 10, the articles 10 will
back up on the main conveyor 12 and the photocell 34 senses
such backup and sends a signal to the PLC to reduce the
speed of the outfeed conveyor B. If the backup of the
articles extends to the condition responsive device 32 as a
CA 02493548 1999-10-27
24
result of the lost spacing between the articles, then the
condition responsive device 32 generates a signal that is
fed to the PLC which stops outfeed conveyor B. This causes
the articles to be loaded into the accumulator from the
bottom of the spiral to the top.
If prior to the transport member D reaching the top of
the spiral a signal is received indicating that the
downstream receiving station can receive more articles, the
PLC under the control of the condition responsive devices 32
and 34 send a signal to the outfeed motor 22 increasing the
speed of the outfeed conveyor B above the speed of the
infeed conveyor A. When this occurs the articles that have
been stored in the accumulator are fed by the outfeed
conveyor B back onto the main conveyor to the downstream
receiving station. Since the articles that are being fed
into the accumulator on the infeed conveyor A is at a slower
rate than they are being removed from the accumulator by the
outfeed conveyor, such causes the transport member to move
in a clockwise direction until the accumulator is entirely
emptied.
Referring now to Fig. 21 of the drawing, there is
illustrated a modified form of the invention. The rotatable
member E, which is driven by the infeed and outfeed
conveyors A and B, has provided on top thereof a thin flat
large diameter metal plate 350 (conveying plate) that
extends over the upper surface of the infeed conveyor A and
outfeed conveyor B for transferring articles 10, being
transported on the infeed conveyor A to the outfeed
conveyor B. The articles being moved on the infeed conveyor
A ride up on the upper surface of the thin metal plate 350,
and as the metal plate 350 is rotated by the rotatable
member E, it transports the articles 10 over the upper
CA 02493548 1999-10-27
surface of the outfeed conveyor B. A deflecting rail 352 is
used for deflecting the articles from the upper surface of
the flat plate 350 on to the conveyor B.
Still another modified form of the invention is
disclosed in Fig. 22, wherein griping arms 354, projecting
outwardly from a rotatable housing 360, are used for
gripping the articles 10 moving on the infeed conveyor A and
transferring the articles to the outfeed conveyor B. The
grippers 354 can be any suitable gripping jaws that are
closed by a cam or any other suitable mechanism as the
gripping jaws pass over the infeed conveyor A for gripping
the articles 10 and transporting them over to the outfeed
conveyor B where they are released. The housing 360 can be
driven by the rotatable member described in the earlier
embodiments.
While the drivers F and G between the rotatable member
E and the infeed conveyor A and outfeed conveyor B has been
shown in one particular embodiment as being post 48 and 52
provided on the lower surface of a conveyor meshing with
teeth 61 provided on the rotatable member E, it is to be
understood that such driving connection between the infeed
and outfeed conveyors A and B, and the rotatable members
could be accomplished by other means such as, for example,
placing sockets or teeth on the conveyor belts A and B and
mounting the posts on the rotatable member E.
In Fig. 18 there is illustrated a different type of
conveyor belt that could be utilized with the invention.
The conveyor belt includes links 300 which are joined
together along the length of the conveyor as well as across
the conveyor. This is a conventional link belt type of
conveyor chain. Posts 302 are mounted to the lower ends of
the links carried on the outside of the chain for driving
CA 02493548 1999-10-27
26
the rotatable member E such as shown in Fig. 10. The
conveyor chain has openings 304 provided therein into which
teeth 306 carried on sprockets extend for producing a
driving relation between the sprockets. The primary
purpose of including the chain of Fig. 18 is to illustrate
that any suitable conventional conveyor belt can be modified
to be utilized as part of the accumulator.
Additional Description
An alternative preferred drive mechanism arrangement
for the infeed and outfeed conveyors is illustrated in the
partial schematic perspective of Figure 23. According to
this embodiment, a plurality, for example three or four,
individual drive mechanisms 22a through 22c and 16a through
16c are provided for the outfeed and infeed conveyors B and
A, respectively. Each drive mechanism includes a motor
driving a gearing arrangement and drive sprocket 402. A
chain 400 is driven by drive sprocket 402 and passes around
an idler sprocket 404. Although not illustrated in Figure
23, chain 400 includes driving engagement members or lugs
that engage with the drive lugs on the bottom of the
conveyors. This type of drive motor arrangement is but one
type of preferred mechanism, and it should be understood
that any manner of conventional drive mechanism may be
utilized in this regard. A suitable preferred drive
mechanism is described in detail in co-pending U.S. Patent
Application Serial No. 09/235,889 filed concurrently with
this application on January 22, 1999 and entitled "Conveyor
Motor Drive Unit and Conveyor System", which has now issued
as U.S. Patent No. 6,119,848.
Applicants have found that the use of individual drive
motors or mechanisms spaced along the conveyors provides a
significant benefit. Each of the motors is individually
CA 02493548 1999-10-27
27
driven and powered and is independent of the other motor
drive mechanisms. Each motor drive has an inherent load-
torque curve wherein the motor will increase or decrease in
speed according to the load carried by the motor, as is
commonly understood. In this regard, referring to Figure 23
and outfeed conveyor B as an example, when outfeed conveyor
B passes over motor drive unit 22a, the links of outfeed
conveyor B are compressed or drawn together due to the
driving action of the motor resulting in a degree of "slack"
generated in the conveyor. This "slack" would tend to bunch
together the articles carried on the conveyor and if the
articles are already in contacting relation, the articles
may be forced off of the conveyor. The use of multiple
independent drive mechanisms substantially eliminates this
occurrence. For example, any slack generated by drive
mechanism 22a is immediately sensed as a decrease in load at
drive mechanism 22b causing drive mechanism 22b to increase
slightly in speed thus taking up any slack generated in the
conveyor. Likewise, drive mechanism 22c will respond
similarly to any slack generated by drive mechanism 22b.
Thus, as a result of the ability of the individual drive
mechanisms to operate independently along their respective
load-torque curves, the problem of slacking and bunching on
the conveyors is eliminated.
The same discussion relating to drive mechanisms 22a
through 22c also relates to drive mechanisms 16a through 16c
and their relationship with infeed conveyor A.
In the embodiment wherein infeed and outfeed conveyors
A and B are in a stacked spiral arrangement, the individual
drive mechanisms are provided at each layer of the stacked
arrangement.
CA 02493548 1999-10-27
28
Each of the individual drive mechanisms is connected
via control lines 406 to a PLC cabinet 408 or other suitable
control system. Each of the individual drive mechanisms is
preferably supplied with the same voltage and frequency
power supply. Control system or PLC 408 may be incorporated
with the same PLC or control system utilized for controlling
the speeds of the conveyors in response to the conditioned
responsive devices 26, 28, 30, 32, 34, as described above.
Figures 24 and 25 illustrate an alternative preferred
embodiment of article transfer member H. This embodiment is
similar in aspects to that illustrated and described with
regards to Figure 21. In this embodiment, rotatable member
E is rotatably driven by engagement with the drivers
provided on the underside of the infeed and outfeed
conveyors A, B. A ring gear 410 is fixed to the upper
surface of rotatable member E and is non-rotatable relative
thereto. A sun gear 412 is disposed concentric with the
central axle 414 of rotatable member E. A plurality of
planet gears 416, for example four, are disposed between sun
gear 412 and ring gear 410. Each of the planet gears
includes an upstanding axle 418. As is conventionally
understood, as the ring gear rotates with rotatable member
E, planet gears 410 will revolve relative to sun gear 412
and rental axle 414, A conveying plate 420 that comprises
an essentially flat thin plate is engaged on each of the
planet gear axles 418. Accordingly, conveying plate 420
will rotate at the same speed that planet gears 416 revolve
around sun gear 412. This gear reduction mechanism is
utilized so that conveying plate 420 does not rotate at the
same speed as rotatable member E. By reducing the
rotational speed of plate 420, articles carried thereon are
CA 02493548 1999-10-27
29
not thrown, moved, or bumped off of the plate, and do not
jam as they are carried onto and off of conveying plate 420.
Conveying plate 420 can comprise any conventional
material, for example, a simple metal plate. It may be
preferred to coat plate 420 with any manner of conventional
coating to, for example, decrease the tendency of the
articles to slide or move on the plate surface.
Figure 25 also illustrates a deflecting rail mechanism
422 that may be incorporated as a preferred feature of the
invention. Rail mechanism 422 includes a relatively rigid
rail member 424 resiliently mounted on transport member D.
For example, rail 424 may be mounted on a frame member 426
carried by transport member D, The deflecting rail
mechanism 422 includes a number of resilient fingers 428
also mounted on frame member 426. Fingers 428 may be formed
of any resilient material, for example a thin flexible
metal, plastic, rubber, or the like. Fingers 428 tend to
press rail 424 outward into outfeed conveyor B, as indicated
in dashed lines in Figure 25. The front end of rail 424 is
rigidly mounted onto a plate member 430 that fits over
central axis 414 of rotatable member E. In this regard, the
resiliency of rail 424 tends to increase from the front or
forward end as the rail extends rearward. In other words,
rail 424 is less resilient where the rail is mounted onto
plate 430 but becomes more resilient by way of fingers 428
as the articles are transferred off of conveying plate 420
and onto outfeed conveyor B. In this way, rail 424 applies
a constant bearing pressure against the articles as they are
transferred onto outfeed conveyor B.
Figures 26 and 27 illustrate an alternate preferred
feature that may be incorporated with the present invention,
particularly an alignment rail mechanism, generally 432.
CA 02493548 1999-10-27
Alignment rail mechanism 120 is also carried by transport
member D and is located adjacent to rotatable member E and
conveying plate 420 so as to align and position articles for
transfer from infeed conveyor A to outfeed conveyor B.
Alignment rail mechanism 432 preferably includes a
relatively rigid rail 434 that is movable towards and away
from infeed conveyor A, as generally indicated by the dashed
lines in Figure 25. Rail 434 is mounted onto a frame member
436 by way of arms 438 that are pivotably mounted to frame
436. An arm 440 extends from arms 438 and carries a weight
442. Weight 442 is variably positionable along arm 440 to
vary the amount of movement, and thus pressure, exerted by
rail 434 against articles conveyed on infeed conveyor A.
Rail 434 may also include a flexible or resilient arm
section 444, generally illustrated in Figure 27. Resilient
arm section 444 may be attached to rail 434 in any
conventional manner, such as the pin arrangement 446
illustrated in Figure 27. Pins 446 allow for variable
positioning and adjusting of resilient arm section 444
depending on the amount and type of articles being conveyed.
It should be appreciated that the alignment rail member
can be configured in a number of alternate ways. For
example, Figure 27 illustrates rail 434 as mounted on a
member 448 that is rigidly fixed to swinging arms 438. Any
type of structure may be utilized to mount rail 434 and to
provide a variable force or positioning capability for the
rail.
As described above, infeed and outfeed conveyors A, B
may be constructed of any suitable conventional chain belt
that has connecting links. The lower surface has driving
lugs provided thereon which are engaged by the belt drive
mechanism. Driver engagement members are also disposed on
CA 02493548 1999-10-27
31
the bottom of the conveyors for engaging rotatable member E,
as discussed above. Applicants have found that a preferred
embodiment of conveyor belts A and B is the type of belt
described and illustrated in pending U.S. Provisional Patent
Application Serial No. 60/107,171 filed on November 5, 1998
and entitled "Conveyor Belt and Modules with Tapered Oblong
Hinge Pins", now U.S. Patent 6,474,464.
While preferred embodiments of the invention have been
described above, it is to be understood that any and all
equivalent realizations of the present invention are
included within the scope and spirit thereof. Thus, the
embodiments depicted are presented by way of example only
and are not intended as limitations upon the present
invention. While particular embodiments of the invention
have been described and shown, it will be understood by
those of ordinary skill in this art that the present
invention is not limited thereto since many modifications
can be made. Therefore, it is contemplated that any and all
such embodiments are included in the present invention as
may fall within the literal or equivalent scope of the
appended claims.
