Note: Descriptions are shown in the official language in which they were submitted.
104~;096
This invention relates to container decorating apparatus
in general and more particularly relates to a novel unloader
which removes decorated containers from a deformable carrier
disposed within the container.
U. S. Patent No. 3,766,851, issued October 23, 1973, to
E. Sirvet et al. for a Continuous Can Printer and Handling
Apparatus describes machinery which decorates undecorated cans,
applies a protective coating of varnish over the decoration,
and transports the varnish-coated can to a curing oven, with
each can being mounted on an individual pin secured to a con-
veyor chain that travels through the curing oven. The cans
are loosely mounted on the pins during the journey through the
curing oven. This arrangement is satisfactory when convection
heating is utilized for curing.
However, in order to reduce the size of the curing oven,
radiation-curing is utilized. This requires uniform exposure
to the radiation source for all portions of the can having an
ink or a protective coating thereon. Because of this, the
conveyor chain pins are provided with radially extending spring
elements, conveniently forming a wire brush-type structure
which serves to center the can with respect to the pin and
frictionally engages the can so that rotation of the brush
will cause the can to rotate. At production speeds in the
order of at least 800 cans per minute, a problem arises in
stripping the cans from the holders and delivering these cans
to an output conveyor without damaging the cans.
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In the prior art stripping of cans from the conveyor
brushes was accomplished by engaging the open ends of the can
with a mechanism that pushed each can from the holder and in
so doing moved the length of the brush traveling axially
through the bristles thereof. At high operating speeds this
stripping mechanism causes rapid wearing of the holders and
often causes damage to the can edge at the open end of the can,
thereby interfering with the application of can tops.
In accordance with the instant invention the unloading
of decorated cans is accomplished by uti~zing suction retrieving
rods mounted to a continuous rotating wheel having a sprocket
portion that engages the conveyor chain at the output of the
curing oven so that cans carried by the holders on the conveyor
chain are guided into and are seated in pockets of a receiving
portion of the wheel. While this operation takes place, a cam
device engages the cans moving them axially forward to positions
where they are slightly forward of a rear stop provided by a
ring or wheel. Each of the retrieving rods is then moved axially
to engage the closed end of the container. Movement of each
retrieving rod and the application of vacuum thereto is programmed
so that after initial engagement of the rod with the can, the
latter pushes the former rearward until the open end of the can
engages the rear stop with slight overtravel of the rod being
permitted by deforming of the suction cup at the free end of the
rod. As the suction cup engages the can, vacuum is
applied to draw the can against the suction cup.
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1046096
Ih.e rod then moves forward to remove the can from the holder
and delivers the can to a poc~et in an output portion of the
rotating wheel. Forward movement of the can is arrested by
engagement thereof with a front rotating plate, at which *ime
vacuum at the suction cup is discontinued and shortly thereafter
the interior of the suction cup is vented to atmosphere and
the rod continues to move forward to separate the suction cup
from the can. Thereafter, gravity transfers the can from the
output pocket to a downwardly extending output chute.
Accordingly, a primary object of the instant invention
is to provide novel means for unloading decoràted cans from
a resilient holder.
Another object is to provide an unloading means of this
type constructed for reliable, high speed operation.
Still another object is to provide an unloading means of
~ this type which utilizes controlled axially moving arms that
! engage the can solely at its closed end.
A further object is to provide an unloading device of
this type in ~hich the retrieving rods and valving therefor
are of novel construction.
A still further object is to provide an unloading device
of this type constructed so that access may readily be had for
the clearing of jams.
These objects as well as other objects of this invention
shall become readily apparent after reading the following
description of the accompanying drawings in which:
Figure 1 is a front elevation of can decorating apparatus
including an unloading device constructed in accordance ~ith
teachings of the instant invention.
Figure Z is a cross-section of the unloading device
rotating wheel taXen through line 2-2 of Figures 1 and 3,
looking in the direction of arrows 2 2.
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Figure 3 is a rear elevation of the unloader,
looking in the direction of arrows 3-3 of Figure 2.
Figure 4 is a fragmentary front elevation of the
unloader, looking in the direction of arrows 4-4 of
Figure 2.
Figure 5 is an enlarged longitudinal cross-section
of one of the retrieving rods taken through line 5-5
of Figure 2 looking in the direction of arrows 5-5.
Figure 6 is a fragmentary end view at the input end
of the unloader looking in the direction of arrows 6-6
of Figure 3.
Figure 7 is an end view of the output conveyor Gh~te
looking in the direction of arrows 7-7 of Figure 3.
Figure 8 is a perspective looking at the in-feed
end of the unloader, generally at the angle indicated bY
arrow 8 in Figure 1.
Figure 9 is a plan view of one of the top guides,
looking in the direction of arrows 9-9 ~`f Figure 3.
Figure 10 is an end view of the top guide of Fig-
ure 9 looking in the direction of arrows 10-10.
Figure 11 is a developme~t of the cam slot used
to control axial movement of the retrieving rods.
Figure 12 is a schematic diagram shown various
positions of a can and retrieving rod during stripping
of the can from the carrier or holder.
Now referring to the figures and more particularly
to Figure 1 which shows apparatus for decorating unde-
corated seamless cans 16 supplied by conveyor means 15.
The latter includes a lead screw 31 feeding cans 16 into
star wheel 32 from whence they are delivered to cradles
17 of wheel 18 that is rotating on shaft 19. Cans 16
are then moved axially on cradles 17 and transferred to
mandrels 20, also mounted on wheel 18. The path of
each mandrel 20 is such that the outer
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cy lindrical surface of each can 16 engages the periphery of
rotating image transfer mat 21 of the printing or decorating
section indicated generally by reference numeral 22.
Decorated cans 33, while still mounted to spindles 20,
engage the periphery of applicator roll 23 in overvarnish unit
indicated generally by reference numeral 24, which applies
a protective coat of varnish over the decorations, Thereafter,
decorated cans 33 are moved to transfer wheel 27 rotating on
shaft 28. From wheel 27 cans 33 are transferred to holders 41
10 each constructed in the form of a wire brush mounted to an
individual pin ~9. Pins 29 are secured to endless conveyor
chain 30 and extend generally perpendicular to the plane in
which chain 30 moves. The path of movement for chain 30 is
defined by sprockets 42-59 inclusive, and extends through
stacked radiation curing ovens 60-63 inclusive, where the
ink or coating on each decorated can 33 is cured, and through
unloader 65 where can 33 is stripped from holder 41.
The constructions and functions of conveyor 15, wheel 18,
decorating section 22, overvarnish section 24, and transfer
20 wheel 27 are described in greater detail in the aforesaid
U. S. Patent No. 3,766,851.
As seen best in Figure 2, sprocket 51 is keyed to shaft 66
that is rotatably supported at opposite ends thereof by
bearings 67, 68 in housing 71 and post 72, respectively, with
the latter being positioned behind the former. Sprocket 51
and shaft 66 are portions of a continuous rotating transfer
assembly that includes rear star-wheel 73, front star-wheel 69>
and retriever rod carrier 70, all keyed to shaft 66. Carrier 70
is mounted in front of front star-wheel 69 and sprocket 51
30 is mounted behind rear star-wheel 73. The periphery of rear
star-wheel 73 includes axially spaced rings 7~, 75. Similarly,
front star-~heel 69 includes axially spac~d rings 76, 77. The
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periphery of each rin~ 74-77 is provided with nineteen equally
spaced notches defining notches or pockets 78 to seat cans 33,
For a reason to be hereinafter seen, pockets 78 o all four
rings 74-77 are in alignment, Also aligned with each of the
pockets 78 is a plurality of hollow vacuum feed tubes 79
mounted to carrier 70 and extending parallel to shaft 66.
The forward end of each vacuum feed tube 79 is connected through
an individual fitting 99, conduit 98, fitting 101, and radial
shaft passage 102 to axial chamber 103 at the forward end of
shaft.66, which in turn is connected through rotating vacuum
coupling 104 to a vacuum source (not shown).
The rear of each tube 79 is entered axially into an
individual retriever rod.80 through its forward end. Each
rod 80 is secured at its forward end to block 81 and is mounted
in bearings 82 for axial movement with respect to carrier 70.
The free or rear end of rod 80 is provided with suction cup 83.
Each block 81 is provided with an individual follower wheel 84
positioned in cam slot 85 formed in ring 86 disposed inside
housing 71. A flat projection of ring 86 and cam slot 85 is
seen in Figure 11, in which the front and rear edges of
ring 86 are designated by reference numerals 86F and 86R,
respectively. Axial movement of each block 81 is guided by
a pair of rods 160, 160.
As seen best in Figure 5, retriever rod 80 is hollow and
is constructed of axially aligned separable front and rear
sections 87, 88.. Disposed within rear section ~8 and extending
along the axis thereof is valve member 90 that is biased
orwardly, or to the left with respect to ~igure 5, by coiled
compression spring 89. Movement of member 90 to the left with
respect to suction cup 83 is limited by engagement of member 90
with the right end of rod section 87. Member 90 is provided
with axial passage 91 that extends from the ri~ht end thereof
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and terminates to the rear of extcrior conical seat 92 at
the forward end of member 90, Transverse vacuum ports 93 of
member 90 communicate with passa~e 91 as do transverse exhaust
ports 94.
~ ith valve member 90 in the position shown in ~igure 5,
there is a continuous vacuum passage from the interior of
hollow vacuum feed tube 79 to the interior of suction cup 83.
This passage extends through the axial passage of rod
element 87, vacuum ports 93, axial passage 91 of valve member 90,
the axial passage of rod section 88 and passage 95, to the
interior of sùction cup 83. Valve member 90 is in the position
of Pigure S when rod 80 is extended ~earward as when suction
cup 83'is engaged with the closed forward end of can 33. -
As retriever rod 80 moves near its most forward position,
conical seat 92 of valve member 90 engages internal conical
seat 96 at the rear end of vacuum feed tube 79. Continued
for,ward movement of rod 80 forces member 90 rearward toward
suction cup 83 until a point is reached where exhaust ports 94
of member 90 are aligned with exhaust ports 97 in rod member 88.
At this time valve member 90 seals off the interior of vacuum
feed tube 79 so that vacuum is no longer being applied to the
interior of retriever rod 80,'and at this time the alignment
of exhaust ports 94 and 97 permits venting of the interior of
suction cup 83 through passage 95, the axial passage through
rod member 88, the axial passage of valve member 90, and
exhaust ports 94, 97.
Sprocket 50 for conveyor chain 30 is rotatably mounted on
horizontal shaft 106 extending rearward from post 107. Also
mounted to post 107 is split positioning plate 108 that is
disposed above shaft 106 and slightly fonYard of sprocket 50.
Platc 108 is provided,with guide slot 109 having tapered
~outh 110 at its lower end. Plate 108 is at a slight angle
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with respect to the vertical so that forward surfaces111 thereof acts as a camming device. That is, the
chain 30 leaves sprocket 50 and moves toward sprocket
51, carrier pin 29 moves through guide slot 109.
During this movement of pin 29, the open end of can
33 rides along surface 111 which moves the can slightly
forward to a position such that the open end of can 33
is slightly forward of stop ring 112 mounted to the
forward side of sprocket 51.
Thus, as cans 33 move above split plate 108 and are
captured in the rotating pockets 78 of rear star-wheel
73, these cans are forward of stop ring 112. The latter
is provided to limit rearward movement of cans 33 as
they are engaged by retriever rod 80 during full rear-
ward extension thereof. The engagement of cans;33 with
stop ring 112 assures thatthere will be firm engagement
between suction cups 83 and the closed ends of cans 33.
Disposed above plate 108 in confronting relation-
ship with the upper peripheral portions of star-wheels
69, 73 are a pair of cover-guides 114,115 seen best in
Figures 3 and 8 through 10. Cover-guide 115 includes
four parallel plastic-coated arcuate guide strips 116-
119 that are secured near opposite ends thereof to sup-
ports 130,131 that depend from the respective transverse
arms 120,121. The forward ends of these arms are
pivotally mounted to housing 71 on aligned pins 123,
123 in formations of support p~ate 152 secured to the
top of housing 71 and extending to the rear thereof.
Quick-release locking devices 124, 124 engageable with
arms 120, 121 maintain cover-guide 115 locked in its
closed or operating position with guide rails 116-119
positioned outboard of star-wheels 69,73, so as to be
very close to the cylindrical surfaces of can 33 to
assure that the latter will remain in guide pockets 78
even at extremely high rotational
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speeds or star-wheels 69, 73. l\~hen locking ~levices 123, 124
are open, the rear ends of arms 120, 121 may be lifted upward
by utilizing handle 126, seeured to arms 120~ 121 near the
rear thereof. Lifting of arms 120, 121 opens cover-guide 115
and thereby permits access to t]le interior of the apparatus
for the clearing of jams and the performance of maintenance
on star-wheels 69, 73 and retriever rods 80. The construction
of cover-guide 114 is essentially the same as the construction
of cover-guide 115 so that a description of the former will
10 not be given herein.
Rear guide rails 116, 117 of cover-guide 114 extend
below arm 121 in the region where cans 33 are brought into
engagement with rear star-wheel 73. Similarly, forward guide
rails 118, 119 of cover guide 115 extend below arm 120 to
guide cans 33 into the upper end of vertically extending
conveyor chute 133 at the outfeed side of front star-wheel 69.
In operation, cans 33 in passing through ovens 60-63
are rotated by virtue of the fact that each pin 29 is keyed
to an individual friction wheel 136 disposed to the rear of
20 chain 30, with wheel 136 rolling across appropriate stationary
surfaces (not shown) disposed within ovens 60-63.
Now considering an individual can as it leaves the upper- ¦
most oven 63 and moves past sprocket 50. Conveyor pin 29
moves through guide slots 110 and the open end of can 33
slides across camming surface 111, causing can 33 to move
slightly forwar(l on carrier Z9, 41. This can 33 then enters
aligned pockets 78 in the periphery of rear star-wheel portions 74,
75. At this transfer location the motions of chain 30 ar~d
star-wheels 69, 73 are blended so can 33 is moving together
30 with rear star-wheel 73. With the position of can 33 stabilized
on star-wlleel 73, suction cup 83 engages the closed end of
can 33 by virtue of the fact that cam follower 84 is r;~in~ at
an appropriate section of cam slot 85 so th~t retriever rod ~û
is being cxtcn(led by being clriven rear~lar(l. ~acllum is now
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present ~ithin cup 83 to produce a firm ~rip between cup 83
and can 33.
Then cam slot 85 acts to retract rod 80, thereby moving
can 33 forward into aligned pockets 78 in portion 76, 77 of
front star-wheel 69. Now can 33 is completely clear of
carrier 41. Retriever rod 80 continues to move rearward,
with the application of vacuum to cup 83 being discontinued
at this time by the engagement of valve seats 92, 96. 5hortly
thereafter the interior of cup 83 is vented to the atmosphere
beGause of alignment between exhaust ports 94, 97. Release
of can 33 from cup 83 is assured, since forward movement of
can 33 is arrested by engagement thereof with front stop
ring lS0 secured to fron~ star-wheel 77 on the forward side
thereof. Stop 150 is in the form of a ring having peripheral
notches 151 which provide clearances for retriever rods 80.
The instant invention has been described in connection
with utilization of suction as the holding force applied between
the retrieving rods and containers, since suction will be
effective on both ferrous and non-ferrous materials; however,
it should now be apparent to those skilled in the art that
when handling containers constructed of ferrous material
magnetic orces may be utilized for holding purposes> and
either permanent magnets or controlled electromagnets may be
utilized in place ofsuction cups.
Although in the foregoing preferred embodiments have
been discussed, many vari~tions and modifications will now
become apparent to those s~illed in the art, and it is there-
fore understood that this invention is not limited by the
disclosure but only by the appending claims.
