Note: Descriptions are shown in the official language in which they were submitted.
3528
BACl:~GROUND OF THE INVE:NTION
This invention relates to the automatic
dispensing of non-round, flexible, elastic containers ~ -
from nested staeks of such containers, and partieularly
to the dispensing of pressed or drawn, flanged paperboard
eontainers having a water- or grease-resistant eoating
(for example, polyethylene or polyester) on the inner
wall of the eontainer. ` `
Such eontainers are being used inereasingly
instead of metal foil eontainers in the ~ood proeessing
industry for a wide range of produets, such as, pies
and other ba~ery items. One advantage of paperboard
eontainers is that they ean be used in mierowave ovens,
whereas metal foil containers should r~ot.
In many eommereial food proeessing applications
eontainers must be automatieally dispensed one at a
time at speeds of up to 150 containers per minute from
the bottom of a nested stack of such eontainers and
deposited onto holders on a traveling eonveyor. The
eonveyor earries the eontainers through the other
operations in the food processing sequence, ineludin~
filling the empty containers with food. It is apparent
that a reliable and accurate method must be used for
automatically dispensing the eontaincrs one at a time
and for depositing thcm on thc earriers.
`~" 2
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11;3352~
The usual apparatus for dispensing metal foil
containers in continuous food processing machinery
employs continuously rotating cooperating screws or
rotors that separate and strip the bottommost plate
from the vertical nested container stack while supporting ~ `
the penultimate plate and the remainder of the stack.
The screws or rotors typically comprise flat, annular
plates having stepped flanges and channels to separate
and dispense the bottommost plate in the stack.
These conventional screw-type machines for
metal foil plates and containers, however, cannot be
used without modification for pressed or drawn paperboard -containers because of structural differences between
metal and paperboard containers. Among these differences
,~, ".,.,,~ . ,
is a bead on the outer perimeter of the flange of the
metal container. When beaded metal containers are
nested, the beads create a space or cleavage between ~;~
the adjacent flanges. A separator blade carried, for
example, by the rotor of a screw-type dispensing machine -
can be easily inserted into the cleaYage between the ~;
-- flanqes of the bottommost and penultimate containers to
separate the bottommost container from and to support
the remainder of the stack. However, it is not feasible
to provide beaded flanges on the pressed paperboard
containers of the type used with the present invention.
- Another structural difference is that paper-
board co~tainers are generally heavier than metal foil
containers. This makes it more difficult to insert a ~ ;
separator blade between the flanges of paperboard
containers as compared to metal containers, for the
following reason. When the nested stack of paperboard
-- . ....
'.-:. :,~.,
3 ;-~
'
,
1J 33528
containers is supported for dispensing on the rotors of ~;
a screw-type dispensing apparatus, the flange of the
bottommost container is supported by the rotors. That
flange is bent upward at the points of support due to
the weight of the stack bearing down on the support
points, causing the flange of the bottommost container
to touch the flange of the penultimate container.
Accordingly, there is no space between the flanges of
the bottommost and penultimate containers into which a
separator blade can be inserted.
A third difference is that aluminum and other
metal containers can be manufactured to more exact tol-
erances than pressed or drawn paperboard containers.
Thus, paperboard containers exhibit wider variations in ~
flange size and other dimensions, making them more dif- `
ficult than metal containers to dispense from a stack.
The art has attempted to overcome these
problems associated with the use of paperboard containers
principally by resorting to the use of vacuum-type
dispensers. In one variation, the vacuum pick and
slide method, a suction source carried by a movable arm ~ `
contacts the bottommost plate on the stack. Movement~ ~`
of the arm separates ~or "picks") ~he bottommost container ~
from the stack. The plate is then deposited at the top ~ -
of an inclined ramp on which the plate slides down onto ~ ;
- the carrier. In another variation, the vacuum pick and
place method~ the bottommost plate is picked from the
stack by a suction source carried by a movable arm and
placed directly onto the carrier by the moving arm.
These vacuum methods are slower, less reliable, and
less economical than the dispenser of the present
~invention.
.. ~ ,
4 - ~ `
~133SZ8 :
SUMMARY OF THE INVENTION
The present invention relates to apparatus
and method for dispensing non-round, flexible, elastic,
1anged containers having corners and non-vertical -
sides, from the bottom of a nested stack of the containers.
Broadly, the apparatus comprises a base and a plurality
of rotor assemblies to operate on the stack, each rotor
assembly being rotatably mounted on the base for synchro-
nized movement with respect to the one or more other
assemblies. Each rotor assembly comprises support
means, separating means, release means, and compressive
means, wherein the support means, separating means, and
release means are rotatably fixed with respect to each
other and the compressive means is rotatably and eccen- ;
trically mounted with respect to the support means,
separating means, and release means. The rotatability
of the compressive means allows non-round trays, which
..
cannot rotate, to be squeezed without cutting into ~-
and/or distorting the trays.
In other words, the apparatus comprises (a~ a
base; (b~ support means on the base for supporting the ; ~ ~
nested stack of containers; (c) compressive means on `~ ~-
the base for creatihg a gap between the flanges o~ the ;~
bottommost and penultimate container by applying opposing
- compressive forces to the sidewalls of said bottommost
- container to cause the containers nested in the bottom- `
most container to rise vertically; (d) separating means
on the base arranged and constructed for insertion into
the gap crea~ed by said compressive means, said separat- ;
ing means also being arranged and constructed so that - - ^
.. - :
it may support the penultimate container and the remainder ` ~
- 5
` ^ 1~33528
- of the stack nested therein; and (e) release means for
releasing the bottommost container from said base and
from the remainder of the containers in said nested
stack; one support means, one separating means, one
release means, and one compressive means comprising a
rotor assembly wherein the one support, separating, and
release means are rotatably fixed with respect to each ;~
other, and the compressive means is rotatably and
eccentrically mounted with respect to the support,
- separating, and release means. ~;
Preferably, the rotor assemblies are positioned
so that the support, compressive, separating, and `:
- release means operate on the sidewalls at the corners
of the non-round containers. .Usually, the support, :.
separating, and release means comprise three discs
having arcuate cut-outs on their peripheries, the discs
being rotatably fixed on the shaft of the rotor assembly,
and the compressive means comprises a sclueezer wheel,
rotatably and eccentrically mounted with respect to the
other three discs. ~ :
- The process of the present invention comprises
the following steps: (a) providing an apparatus having
~. a plurality of ~he foregoing rotor assemblies; (b) `: :
supporting a nested stack of non-round flexible, elastic ~`
... ,: ~'. .
containers, each of said containers having a sloped
- sidewall and a flange extending outward from the sidewall;
(c) rotating the rotor assemblies to separate the
flange of the bottommost container from the flange of
the second to the bottommost (penultimate) container by
compressing the sidewalls of the bottommost container; :~
(d) rotating the rotor assemblies to insert supporting
y - -
. - 6
~133528
means in the space thereby created between the flanges
of the bottommost and penultimate containers and decom-
press the side wall of the bottommost container; and
(e) rotating the rotor assemb]ies to dispense the
bottommost container frPm the remainder of the containers,
- ~ preferably by removing support from the bottommost -
container while at the same time maintaining support
for the remainder of the containers. Thereafter, these
steps may be repeated to dispense additional containers
from the nested stack of containers.
The present invention exploits the structural
elasticity of pressed or drawn paperboard containers, a
property which aluminum containers do not possess to
any significant extent. Advantageously, the new rotor
àssemblies can be used with e~uipment now employing
conventional screw-type dispensing apparatus. -~ U.S. Patent Nos. 1,907,713 and 1,907,714 both
to Benson, disclose screw-type paper cup dispensing ;
apparatus wherein the beaded rim of the bottommost cup
in a nested stack of cups is compressed to overcome the `~
tendency of the bottommost cup to adhere to the rest of
the stack and to insure that the cups feed properly. -
However, in the present invention the sidewalls of the
containers, not their flanges, are compressed, and this `~
compression is applied to the walls of the bottommost ~`
- container in the nested stack to create a space between
the flanges for receiving a separator blade, not, as in
Benson's patents, to overcome the adhesion force between
containers. ~ --~ -
Furthermore, the paperboard containers used
with the present invention have little or no tendency ~ ;
' . , ~ ,
". . .......................................... - . : ~:
., , - .~ ;.
~L133SZ8
to adhere to one another, as do Benson's cups. First,
the containers used herein, unlike Benson's containers,
have walls which are not substantially vertical.
Second, the polyethylene or polyethylene and polyester
on the inner walls of the containers preferably used
herein further diminishes the adhesion between the
containers.
BRIEF DESCRIPTION OF THE DRAWINGS -
To more fully describe the present invention,
the following drawings are provided, in which:
Fig. 1 is a perspective view of a non-round
container (or tray) that can be dispensed by means of
the present invention;
Figs. 2, 4, and 6 to 9 are diagramatic top
views of the tray of Fig. 1 being operated on by rotor
assemblies constructed in accordance with the present
invention, showing possible locations and directions of
rotation (set-ups) of the squeezer wheels of those
assemblies;
Figs. 3 and 5 are schematic top views of the
trays of Figs. 2 and 4, respectively, showing (to a
somewhat exaggerated degree) the change in tray dimensions
caused by the squeezer wheel rotations shown in Figs. 2 -~
and 4, respectively; ~ ;
Fig. 10 is a perspective view of a machine ~;
embodying the present invention for dispensing trays
one at a time from a stack of the trays of Fig. l;
Fig. 11 is a top view of the machine of
Fig. 10;
Fis~. 12 is a partial, front, sectional view
of the machine of Fig. 10 taken at line 12-1~ of Fig. 11; ~
~ ":
8 ~
~ "
~3352~
Fig. 13 is a partial, side, sectional view of
the.machine of Fig. 10 taken at line 13-13 of Fig. 11;
Fig. 14 is a partial, top view of the machine
of Fig. 10 showing the squeezer wheels of the four
rotor assemblies compressing the corners of the lowest
tray in the stack of trays;
Fig. 15 is a partial, exploded view of the
preferred rotor assembly;
Fig. 16 is a bottom, partially exploded, ~ ;
perspective view of the rotor assembly of Fig. 15;
- Fig. 17 is a partial, bottom view of the ~ -
rotor assembly of Fig. 15; ~ ~
~igs. 18 to 22 are sequential action views ; `
illustrating steps in the present process utilizing the
apparatus of Fig. 10;
Fig 23 is a partial, perspective view of a
machine according to the present invention for dispensing
trays having two corners, one at a time from a stack of
such trays; and ~` ;^
~ig~ 24 is a partial, top view of the machine
of Fig~ 23 showing the two rotor assemblies compressing
the corners of the lowest ~ray in the stack of trays.
These drawings are provided for illustrativé
purposes o~ly and are not intended to limit the scope
of the in~ention. ;i
~ETAILED DES~RIPTION OF THE INVENTION
- T~e trays employed with the present invention
are non-round, that is, they have corners. For purposes -
. . ,.; . ~ .
of the present description, the word "corners" is to be --
given a broad meaning. Generally, the sides of a tray - `-~
having the greatest curvature(s) will be considered to
~ 33528
be the corners. Also, it should be understood that the
terms "walls" and "sidewalls" as used herein include
those portions of the corners between the tray bottom
and flange.
In Fig. 1, non-round tray 30 has bottom 40,
side walls 36a and b, side end walls 38a and b, unbeaded
flange 34, and corners 32a, b, c, and d. The four
walls, 36a, 36b, 38a, and 38b, including the corners,
32a, b, c, and d, are non-vertical and slope inward
from top to bottom.
The rotor assemblies of the present invention
may be positioned to operate anywhere along the outside
of the trays, but preferably operate at the corners, as
shown in Figs. 2 and 4. Corner placement is preferred ~ ;
for several reasons First, if the tray is small,~ `
corner placement prevents interference of one rotor
assembly with another. Second, apparatus using corner ` `
placement is less sensitive to dimensional variations
of the tray than apparatus using side placement. For ~;
example, in a tray measuring 5 inches wide by 8 inches
long, a one-eighth inch variation in width changes the --
diagonal by only one-sixteenth of an inch. Third,
squeezing to make a space between the flanges of the
bottommost and penultimate trays works best at the ;~
corners because the corners are rounded and, thus, less
friction is encountered. Fourth, the flanges are
strongest at the corners and, thus, tend to bend less -
when the tray is being supported there.
Fig. 2 shows rotor assemblies having squeezer x
wheels 42a, b, c, and d located at the corners of the
tray wherein the axes of wheels 42a and d rotate clockwise ~ ~
'- ''
. ' ' .
1133SZ8
and the axes of 42b and c rotate counter-clockwise.
Fig. 3 indicates (to an exaggerated degree) the resulting
lengthening and narrowing of the tray.
Fig. 4 shows the axes of squeezer wheels 42a
and d rotated counter-clockwise and the axes of 42b and
c rotated clockwise. Fig. 5 indicates (to an exaggerated
degree) the resulting shortening and widening of the
tray.
Figs. 6 and 7 show side placement of the
rotor assemblies wherein the axes of squeezer wheèls
42a, b, c, and d all rotate clockwise or counter-clockwise,
respectively. These set-ups are generally least preferred
of those shown because they tend to cause the trays to
"rack," that is, distort to a parallelogram having
other than right angles (when viewed from the top).
For example, in Fig. 6, side 36a will tend to move to
the left and side 36b will tend to move to the right.
In Fig. 8, the axes of squeezer wheels 42a
and d rotate clockwise, and the axes of wheels 42b and
c, counter-clockwise. This results in tray elongation
and narrowing, similar to that shown in Fig. 3.
In Fig. 9, the axes of squeezer wheels 42a
and d rotate counter-clockwise, and the axes of 42b and
c, clockwise. This results in tray shortening and :
widening, similar to that shown in Fig. 4. `~
Rotor assembly placement and rotation direc-
tion depend on the size and shape of the tray to be
dispensed. For rectangular trays, the set-up of Fig. 2
is generally preferred. For square trays, the set-ups `~
of Figs. 2 and 4 are equally preferred. For rectangular
trays, the set-ups of Figs. 8 and 9 are less preferred,
and the set-ups of Figs. 6 and 7 are least preferred
1 1 . .
.
,: .: . . ." ,, : , ,,::: . .. .
133528
because sometimès the penultimate tray and the bottommost
tray are squeezed at the same time and the required
space or gap between them is not made.
Fig. 10 is a perspective view of a machine
embodying the present invention for dispensing the tray
shown in Fig. 1 from a stack of such trays. The machine
has base 50 supported by legs 82 and opening (or cut~out)
78 in the base through which trays 30 dispensed from
the bottom of stack 52 fall one at a time onto conveyor
belt 80. (It should be understood that one machine may ~ ;
dispense trays from several stacks at the same time; ,~
- however, for simplicity a one-stack machine is shown
and described.)
External drive means (not shown), for example, :~
a motor, rotates shaft 56 and mitre gears 60a and b
fixedly mounted thereon, the shaft being rotatably
mounted on base 50 by journal blocks 54c and d. This,
in turn, rotates mitre gears 62a and b, which are ~ ~-
meshed with gears 60a and b, respectively. Gears 62a
and b are fixedly mounted on shafts 58a and b, which
shafts are rotatably mounted on base 50 by journal
blocks 54a and b, and 54e and f (not shown), respect-
ively. Rotation of shaft 58a and mitre gears 64a and ` -
b, fixedly mounted thereon, rotates mitre gears 66a and
b, which are meshed with 64a and b, respectively.
- Rotation of shaft 58b and mitre gears 64c and d (not
shown), fixedly mounted thereon, rotates mitre gears 66c
and d (not shown), which are meshed with 64c and d,
;,.
respectively. - ` ;
Mounting blocks 70a and b (not shown) support ~ `~
stack guides 74a and b (not shown), respectively. ~ -
'.
12
r
`` -` 1133~Z8
.
Mounting blocks 68a and b (not shown) support stack
guides 72a and b (not shown), respectively. Stack
guides 76a and b (not shown) extend below the b~ttom of
base 50 and will be further described below.
In Fig. 11, a top view of the machine of
Fig. 10, journal block 54f, mitre gears 64d and 66d,
mounting blocks 68b and 70b, and stack guides 72b, 74b,
and 76b, none of which is shown in Fig. 10, may be
seen.
In Fig. 12, a partial, front, sectional view
of the machine of Fig. 10 taken at line 12-12 of Fig. 11, `
two rotor assemblies, indicated generally as 90a and b,
are shown. Only assembly 90b will be described,
assembly 90a being a mirror image thereof. ~ ;`
- Shaft 92 ~grease stem) is rotatably mounted ;
in base 50 by roller bearing assembly 99 containing
rollers 102 and having roller bearing sleeve 100.
Mitre gear 66b, which meshes with mitre gear 64b, is , ~
attached to shaft 92 by two set screws (not shown) - `
through the side of the gear into the shaft. Gear
;
cap 94 is held in place by screw 96, which adjusts the ~~~
pre-load on roller bearing assembly 99. Top shield 98
. ~ ..
rides on ring 97 an~, therefore, rotates with the inner `
portion of the roller bearing assembly. O-ring 106,
- which does not rotate, prevents dust fxom reaching the `-
- roller bearings. - ;
Screw 120 connects the bottom portion of the ~,
- ` rotor assembly to the bottom of shaft 92. This bottom
portion compr.ises blade hub 104 and mounting cup 118.
Between them are several concentrically and fixedly -;
:
mounted discs: separator blade 108, wiper blade 110 ~ ~
- ~ .
- ' ' '~
13
.' ~
` `:. '
..
" ~133528
having cam 112, `shim 114 (providing extra spacing, if
required, because of the tray flange thickness), and
top-disc 116.
The squeezer wheel assembly is eccentrically
mounted in mounting cup-118 by bearing stud 130 and
screw 132 Squeezer wheel 122 is attached to squeezer
wheel hub 124 by scrèws 126. Flange bearing 128 is -~
press-fitted into hub 124, and squeezer wheel 122,
hub 124, and bearing 128 rotate around stud 130 as a
unit. Timken tapered roller bearings and Oilite flange
bearings have been found suitable for some applications.
To insure that separator blade 108, wiper
blade 110, shim 114 (if needed), and top disc 116 are
rotationally aligned, each is provided with a hole that
must be lined up with a hole in blade hub 104 and a
hole in mounting cup 118. The entire passageway formed ~ '
by the aligned holes is indicated by reference numeral 138.
Pin 140 is press-fitted into passageway 138, and the ;~ ~-
pin maintains the several parts in alignment during ;~
operation. Each hole 136 allows a narrower pin (not
shown) to be dropped through it into the top of hole 138 `
~ :.
to insure that all rotor assemblies have been properly
mounted to operate in sync. Pin 141 maintains hub 104,
.
and thus the rest of the assembly (via pin 140), in -~
alignment wi-th shaft 92.
- In Fig. 12, flange 34 of bottommost tray 30a ~;
is resting on top disc 116, and squeezer wheel 122 is
pushing against corner 32, thus forcing penultimate
tray 30b (and the remainder of the stack of trays) to
rise vertically. The position of tray 30a as it later
.:
will be dropped from stack 52 is shown in phantom
.
14 --
" 1133S~8
lines. (Note that distances shown between the flanges
of the trays in stack 52 have been exaggerated for
clarity.)
Fig. 13 is partial, side, sectional view of
the machine taken at line 13-13 of Fig. 11. Guides 76a ~ `~
and b extend below the bottom of base 50 to almost the
bottom of the stack. Guides 74a and b extend below the
bottom of the stack and help keep tray 30a from tipping
as it descends to conveyor belt 80.
Both sets of guides are closely adjacent to
the stack. In this embodiment the tray is being compressed
by squeezer wheels whose axes are rotating as shown in
Fig. 4. This causes widening and shortening of the
tray (the width is the left-to-right distance of the
tray in Fig. 13). If guides 76a and b extended to the
flange of the bottom tray in the stack, the bottom
tray, when compressed by the squeezer wheels 122 (and,
thus, widened) might jam against those guides. Because
this rotor assembly set-up causes the tray to shorten ~`~
~the distance perpendicular to the view of the trays in
Fig. 13), guides 74a and b may extend to or beyond the
bottom of the stack. ~-
If the set-up of Fig. 2 were used, the tray
would tend to narrow and lengthen, and guides 76a and b
could extend below the bottom of the stack to the
position shown by phantom lines 77, but guides 74a (and
b) would have to be raised above the flange of the tray
being squeezed, to the position shown by phantom line 75a.
One or the other set of guides should extend below the ~;
flange of the tray being squeezed (and, if necessary, ~ ;
almost to the conveyor) to help prevent the tray dispensed -
from tipping before it reaches the conveyor.
: ~'
.: ..
, .. . . . ~ .. ,., .. . ~,, .
133528
.
Fig. 14 is a partial, top view of the machine
of Fig. 10. Rotor assemblies 90a and c rotate counter-
clockwise and 90b and d rotate clockwise. Each of the
respective sgiueezer wheels, however, rotates in the
direction opposite that of the rest of the assembly
because of frictional engagement of the wheel against
the respective tray corner, 32a, b, c, or d. Deformation
of the corners, due to compression of the squeezer
wheels 122, is shown.
Fig. 15 is a partial, exploded view of a
rotor assembly built in accordance with the present
invention. Mitre gears 64 and 66 are meshed, and ;~
rotation of shaft 58 causes gear 66 to rotate. As
described above, gear 66 is fixedly connected to shaft 92
(as shown in ~ig. 1~) by two set screws (not shown). -
Gear cap 94 is held in place by screw 96. The shaft is
rotatably mounted in base 50 by means of roller bearing
assembly 99 having sleeve 100. Blade hub 104, separator ~
blade 108, wiper blade 110, top disc 116, and mounting `
cup 118 are fixedly connected to shaft 92 by screw 120 ~
- ~ (see Figs. 12 and 16). Holes 138a, b, c, d, and cut-out 142 ~ `
in hub 104, blade 108, blade 110, disc 116, and cup 118, i
respectively, comprise passageway 138 (see Fig. 12) for ~ ~-
pin 140. The pin maintains the alignment of these
elements with respect to one another during operation.
- Hole 136 in base 50 allows a pin (not shown) to be
temporalily placed in the top of hole 138a for timing
(synchronization) purposes. There are four cut-outs 14
spaced at 90 degrees on the periphery of cup 118. This
allows cup 118 to be placed in any one of four positions
before screw 120 is tightened. (The reas~on for this
~will be explained below.)
,:- ~ - :.. ~.
,~ :
16
;
i. ,., -
.:.' ~,..
1133528
Separator blade 108 has an arcuate cut-out
around its periphery defined by edges 146a and b.
Wiper blade 110 is smaller in outer diameter than
blade 108 except for downwardly turned cam 112 on the
wiper blade's periphery. Top disc 116 has an arcuate
cut-out around its periphery defined by edges 148a and `
b. These three discs are arranged so that the cut-out
of the separator blade is above a portion of the top ~ -
disc that is not cut out, the cut-out of top disc 116
lQ is below a portion of the separator blade that is not
cut-out, and cam 112 is above the cut-out of top disc 116.
~.
Separator blade 108, wiper blade 110, and top ~ ;
disc 116 are essentially circular, but for certain ;
trays, other blade and disc shapes may be required. In
some cases, where the tray flange is too narrow and
sidewall compression moves the flange in too far, a
bump or protuberance may be provided on the top disc to
reach far enough in to contact and support the flange.
Squeezer wheel 122 is attached to squeezer
: .. .
wheel hub 124 by screws 126, and the squeezer wheel,
hub 124, and flange bearing 128 rotate about bearing
. :. -: . .
stud 130 as a unit. Screw 132 connects bearing stud 130
. : ..:
to mounting cup 118. Squeezer wheel 122 is, thus, free
to rotate with respect to the rest of the rotor assembly. ~`~
Fig. 16 is a bottom perspective view of the
- rotor assembly of Fig. 15. ~s previously described,
- ~.,. ~ . .
cup 118 can be placed in any of four positions before
screw 120 is tightened. This allows any one of the ;
four holes 144 to be brought into position to receive
,. i
screw 132.
: ;
- ;,,,
17
1~33528
Referring to-Fig. 17, because the holes 144
are at different distances from axis 150, the axis of
rotation of squeezer wheel 122 can be made closer to or
~arther from axis of rotor assembly rotation 150,
depending on in which one of the four positions mounting
cup 118 is placed. Accordingly, the distance the edge
of squeezer wheel 122 extends past the edge of discs
and blades 108, 110, and 116 (and, therefore, the
amount of squeeze) can be varied.
Figs. 18 to 22 are seguential action views
illustrating the steps of the present process carried
out using the machine of Fig. 10. In Fig. 18, rotor ~-,
assembly gOb is positioned such that the flange of
tray 30a at corner 32c rests on top disc 116. (For
- convenience, the operation at only one corner of the
tray will be described; however, it should be understood
- that the rotor assemblies at diagonally opposite corners
are the same and that the two pairs of assemblies are ~;
mirror images of each other.) The entire stack 52 is
nested in tray 30a and is, therefore, supported by the
four top discs 116. The arrow on blade hub 104 indicates
::~ ".
the direction of rotation of the rotor assembly. -
Because sgueezer wheel 122 is not touching tray 30a, `
".. ..
the wheel rotates as a unit with the rest of the rotor
assembly. ~ ,
: ,
~ Fig. 19 shows rotor assembly 90b rotated ~ ;
approximately 90 degrees from i~s position in Fig. 18.
Squeezer wheel 122 has now contacted and fr.ictionally
engaged corner 32c of tray 30a. Accordingly, wheel 122 ~ ;
, .
is rotated about its axis in the direction opposite to ~
that shown for the rest of the rotor assembly. Compression
, . . ~
. ~..... .
. 18
:1133528
o~ the four corners by the squeezer wheels forces
penultimate tray 30b and the remainder o the trays of
stack 52 to ri~e vertically, as shown by the arrow
abo~e the stack, thereby creating a gap between the
~langes of bottom tray 30a and penultimate tray 30b.
Continued rotation of assembly 90b brings separator
blade into position between the flanges at the corners
while maintaining compression. ;
For most shapes and sizes of trays having
corners, it is best if the trays are sgueezed by the
sgueezer wheels no higher than half-way up the sides of
the trays. Squeezing higher may cause the penultimate
tray in a stack to become trapped within the bottommost
tray and, thus, fail to produce the required gap.
Ho~ever, for some trays, such as the one shown in ;
~igs. 23 and 24, squeezing above the middle is preferred. ;
The circumferential side of the squeezer
wheel may have any shape (e.g., V-shaped, stepped,~ ~
knurled, or chiselled) but usually it will be flat~ ~ -
because of ease of manufacture. Preferably if flat, it ~ -~
~i11 be approximately square (90 degrees) to the wheel
~aces. The degree of sharpness of the portion of the
~heel ~queezing the` tray is determined by the slope of
the tray side, the thickness of the sidewall, the; `~
material from which the tray is made, the weight of the
stack, and the amount of squeeze required. If the
portion of the wheel contacting ~nd squeezing the tray
is too sharpl d~ring compression the wheel may bite
through the ~all of the bottommost tray to the penulti- s~
~ate or even ~he antepenultimate tray. If not sharp
cno~gh, all th~ trays in the stack will rise. In
19
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~ ~3352~
.
either case, the required gap between the flanges of
the bottommost and penultimate trays will not form.
In Fig. 20, assembly 90b has been further ~ `
rotated so that squeezer wheel 1~2 no longer contacts
and compresses corner 32c of tray 30a. Accordingly,
squeezer wheel 122 no longer rotates on its own axis
with respect to the rest of the rotor assembly as it
did in Fig. 19. Because of the decompression, penulti-
mate tray 30b and those nested in it have moved down,
1~ as indicated by the arrow above stack 52.
The flange at corner 32c of tray 30a rests on
top disc 116, and the flange at the corner of tray 30b
rests on separator blade 108. Thus, all the trays
above tray 30a in stack 52 are resting on separator
blade 108. The distance between blade 108 and disc 116 -
should be large enough so that blade 108 does not rub
the flange of bottommost tray 30a when tray 30a is `~
resting on disc 116. If wiper blade 110 is not thick ~ `~
enough to provide the required spacing, shim 114 may be ~
2~ added, as shown in Fig. 12. ~ ;
Continued rotation of assembly 90b (Fig. 21) ~-
. ~
- brings edge 148a (shown in fig. 20) and the rest of the ; `
: ,
arcuate cut-out of top disc 116 under the flange at the
corner of tray 30a. This allows tray 30a to fall, and
penultimate tray 30b becomes the bottommost tray in the ;-
stack. ;
In high speed operation, gravity alone may
~ . .
not be sufficient to cause tray 30a to fall quickly`~
enough. Therefore, cam 112 on wiper blade 110 is
provlded (see Fig. 12 and 15). If tray 30a had not ;
fallen out of the way by the time cam 112 had contacted
. :
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1~L335Z8
it (a few degrees of rotation beyond the position shown ~;
in Fig. 21), the cam would have pushed the flange at
the corner of the tray down. Note that tray 30b and
those nested in it are still being supported by the ~
separator disc 108. `
Referring to Fig. 22, further rotation of ~
assembly 90b brings the arcuate cut-out of separator -
disc 108 (defined by edges 146a and b) under the flange ;
at the corner of tray 30b. This allows the entire
stack of trays to fall, as indicated by the vertical
arrow above the stack. The bottommost tray, 30b, and
all the trays in stack 52 nested therein are supported
by top disc 116. The positions of the rotor assembly
and stack shown in Fig. 22 are the same as those shown
in Fig. 18, except that tray 30a has-been dispensed and ~;
- tray 30b is now the bottommost tray in the stack.
Thus, one cycle has been completed.
- Fig. 23 is a partial, perspective view showing
an apparatus employing the present invention for dispens- ,
Z0 ing oblong trays 160 having corners 162a and b and ``-~
flange 164. (For simplicity, the base, gear system,
etc., of the machine, and the rest of the stack of
trays are omitted.) Two rotor assemblies, 166a and b, ; ;
one at each corner of the tray, are employed. The `
stack rests between side guides 170, side rods 172 `
- mounted in blocks 174, and guides 176 (only one of
which is shown). In Fig. 23, tray 160a has been dis~
- :
pensed from the bottom of the stack and has landed on
conveyor belt; 168, making tray 160b the bottommost tray
in the stack. Rotor assemblies 166a and b are essentially
the same as rotor assemblies 90a, b, c, and d shown in
, , ,
., 21 ~
1~335Z8
Figs. 10 to 22. Preferably, the distance between the
bottom of side guides 170 and conveyor belt 168 is less
than the height of each tray 160 to insure that the
tray lands upright.
Fig. 24 is a partial, top view of the system
o Fig. 23. In Fig. 24, rotor assemblies 166a and b
have been rotated so that s~ueezer wheels 178 deform
corners 162a and b of the bottommost tray in the stack.
This causes the penultimate tray and all those nested ;
in it to rise, creating a gap between the flanges of
the bottommost and penultimate trays. The separator
discs will be rotated so that they are inserted into
the gap, and the cycle will proceed as described above
(see -text accompanying Figs. 18 to 22). Both rotors in
this embodiment are identical and rotate in the same --
direction. The rotors may also be mirror images of
,
each other and rotate in opposite directions if the
side guides can be positioned to prevent displacement ;
of the trays to one side or the other.
In practicing the present invention, the
novel rotor assemblies will usually be placed at the -
corners of the tray. The sizes of the vàrious components ~-~
.,. :
of the rotor assembly should be machined accurately and ^; -
may be selected easily by one skilled in the art.
Obviously, there is a range of suitable component sizes
.: . -^..
for any one tray. Among the factors influencing the
size of the assembly are size and shape of the tray,
desixed maximum dispensing rate ~trays/unit of time),
mechanical properties of the material(s) of construction
(e.g., machinability), space available for the machine,
and cost. ~ -
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5.
, 22
~L133528
F~r a tray having the shape of that shown in
Fig. 1 and measuring approximately 5 inches wide by 7
and 11/16 inches long by 1 inch deep and having a
1/4-inch wide flange, a rotor assembly having the
~ollowing dimensions (approximately) has been found
suitable. Referring to Fig. 12, the overall height
(top of screw 96 to bottom of bearing stud 130) is
3 and 7/8 inches; the top of squeezer wheel 122 is
5/8 inch from the bottom; mounting cup 118 is 11/16 inch ~
from the bottom; the top of blade hub 104 is 1 and ~ .!
13/16 inches from the bottom; the top of top shield 98 ~ ;
is 2 and 3/4 inches from the bottom.
Separator blade 108 and top disc 116 are 2
: .
and 15/16 inches in outer diameter and 0.06 inch thick; `~
wiper blade 110 is 2 and 3/8 inches outer diameter, not .
including cam 112, 2 and 15/16 inches outer diameter
including cam 112, and 0.03 inch thick; squeezer wheel 122
is 2 and 5/8 inches in diameter and 1/8 inch thick. ~ '?,"
The axis of rotation of squeezer wheel 122 is 1/2 inch
from the axis of rotation of the rest of the rotor
i ,,
assembly. The arcuate cut-outs on separa~or blade 108 ~ -
a~d top disc 116 extend approximately 130 and 90 degrees,
respectively, aroung the respective peripheries. `~
, , .
Cam 112 on wiper blade 110 subtends a 37 degree angle. -~
. . ~ ~.,
Modifications and variations will be obvious ~- ~
to one skilled in the art, and the claims are intended ;
to cover all such modifications and variations as fall L~
within the true spirit and scope of this invention.
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