U.S. patent application number 11/484071 was filed with the patent office on 2007-07-19 for can end conversion system.
Invention is credited to Henry C. Bachmann, Mark F. Broerman, Dale R. Conley, Stephen T. Cook.
Application Number | 20070166131 11/484071 |
Document ID | / |
Family ID | 38263333 |
Filed Date | 2007-07-19 |
United States Patent
Application |
20070166131 |
Kind Code |
A1 |
Cook; Stephen T. ; et
al. |
July 19, 2007 |
Can end conversion system
Abstract
A system for converting end shells into container ends complete
with foil-type tabs covering pour openings formed in the shells
utilizes a conveyor comprising at least one continuous belt, or a
plurality of such belts operating in parallel, passing around first
and second sets of drive drums. The belt(s) are driven
intermittently to advance end shells in the nests first through end
forming tooling and then through tab forming/attaching and
reforming tools One set, or both sets, of the drums are driven to
move the belt(s) step-wise along an upper flight, such as to
advance the nests in predetermined increments, and a lower return
flight. The progressive end conversion tooling for shaping the
shells into container ends, with formed and finished pour openings,
is located in the mouth or entrance of a press, and the belt(s)
passes the nests and shells therein between the upper and lower
conversion tooling sets. The tab forming and application tooling is
located beyond the conversion tooling but preferably within the
boundaries of the mouth of the press. A supply web of foil material
is fed step-wise across the conveyor(s) at the beginning of the tab
forming and application station and a blanking apparatus at each of
the application locations acts to create and to separate (e.g. die
cut) tabs from the foil, and tack the tabs against the shells
covering the pour openings. The tabs are then heat sealed over the
pour opening. The areas around the pour opening=s rolled
perimeters, with the foil-tabs attached, then are re-formed to
provide a surface sloping slightly downward and away from the pour
opening to enhance adhesion of the tabs to the shells in that
region, using unique heated tooling
Inventors: |
Cook; Stephen T.; (Dayton,
OH) ; Bachmann; Henry C.; (Dayton, OH) ;
Conley; Dale R.; (Dayton, OH) ; Broerman; Mark
F.; (Dayton, OH) |
Correspondence
Address: |
FAY SHARPE LLP
1100 SUPERIOR AVENUE, SEVENTH FLOOR
CLEVELAND
OH
44114
US
|
Family ID: |
38263333 |
Appl. No.: |
11/484071 |
Filed: |
July 11, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10691446 |
Oct 22, 2003 |
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11484071 |
Jul 11, 2006 |
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60420397 |
Oct 22, 2002 |
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Current U.S.
Class: |
413/52 |
Current CPC
Class: |
B21D 51/383
20130101 |
Class at
Publication: |
413/052 |
International
Class: |
B21D 51/26 20060101
B21D051/26 |
Claims
1. A system for processing can end shells into easy open can ends
having a foil type tab covering a pour opening, comprising first
and second sets of progressive tooling for working on end shells,
said tooling having cooperating upper and lower parts and being
arranged in successive stations along a predetermined processing
path to form a predetermined pour opening in the shells and then to
attach a foil type tab over such pour openings, a continuous
conveyor belt having regularly spaced openings therein spaced apart
corresponding to the spacing of the tooling stations, said openings
extending along at least one lane longitudinally along said belt,
first and second drums supported respectively at opposite ends of
said predetermined path to define upper and lower flights of said
conveyor belt, the path extending through said first and second
sets of tooling, means for driving said belt around the first and
second drums in incremental steps corresponding to the spacing of
the tooling and moving said upper flight through said first and
second sets of tooling when the tooling parts are opened, shell
carrier nests fitted into said openings in said belt, said nests
including an array of flexible fingers adapted to engage a major
extent of the periphery of a shell to hold the shell therein during
conversion work on the shell as the shell is passed through said
tooling, attachment means on each of said nests fastening the
respective said nest to said belt along a line transverse to said
belt to allow each said nest to pass around said drums, a loading
station along said upper flight of said belt located between said
first drum and the first set of tooling stations, means at said
loading station for presenting an end shell to each nest located at
said loading station and placing a presented end shell onto said
fingers. means defining an unloading station beyond said second set
of tooling whereby each completed end processed through said
tooling sets is removed from said belt, means for moving a web of
foil tab material in increments over and across said belt at the
location of the first stations of said second set of tooling to
present foil material over a pour opening in a shell, said second
set of tooling including means for blanking a tab from the foil
material and pressing the resultant tab onto the shell as a closure
to said pour opening and further means for reforming the region of
the shell around the pour opening with the tab in place.
2. A conveyor system as defined in claim 1, further including
insertion means located between said loading station and the first
of said tooling stations and driven synchronously with said
progressive tooling to insert the end shell into full engagement
with said fingers of said nest.
3. A conveyor system as defined in claim 1 wherein said nests each
include a base ring having a peripheral ledge dimensioned to seat
upon the edge of said openings in said belt, said fingers being
formed as integral inwardly projecting extensions from said base
ring spaced apart around the interior of said base ring, said
fingers include shoulders thereon defining an interrupted circular
surface adapted to press against the periphery of an end shell to
retain the shell stationary in the nest while permitting limited
motion of the shell as it is engaged by the tooling.
4. A can end conversion system comprising at least one flexible
belt supported in a loop path including upper and lower flights,
means for moving said belt lengthwise in a predetermined direction
with an intermittent motion of predetermined increments, a
plurality of nests attached to said belt along centerlines which
are parallel to the loop path of said belt and extending in at
least one lane longitudinally of said belt whereby each nest can
traverse the extent of the loop path along said upper and lower
flights, each said nest having at least one nest ring for receiving
and securely holding a can end shell, the nest rings in the
respective nests being aligned along said at least one lane
longitudinally of said belt, successive ones of said nests being
spaced apart a common distance which is equal to the increment of
motion of said at least one belt, means for raising and lowering a
section of said belt and attached nests along said upper flight of
said belt during each incremental motion thereof, first and second
sets of progressive tooling for working on end shells, said tooling
having cooperating upper and lower parts and being arranged in
successive stations along a predetermined processing path to form a
predetermined pour opening in the shells and then to attach a foil
type tab over such pour openings; means for moving a web of foil
tab material in increments over and across said belt at a location
along said belt past the first set of tooling to present foil
material over a pour opening formed in each shell, the second set
of tooling including means for blanking a tab from the foil
material and pressing the resultant tab onto the shell as a closure
to pour opening and further means for reforming the region of the
shell around the pour opening with the tab in place, and means for
unloading completed can end shells from the nests.
5. A system as defined in claim 4, wherein said means for unloading
is located at the beginning of the lower flight of said belt,
adjacent the beginning of the lower flight of said belt.
6. A system as defined in claim 4, wherein there are a plurality of
conveyor belts supported parallel to each other and each belt
having at least one lane of nests, said means for moving foil tab
material extending across all of said belts, and said means for
blanking tabs are relatively oriented in adjacent lanes such that a
substantial majority of the foil tab material is cut from the web
of foil material.
7. In a system for processing can end shells into easy open can
ends having a foil type tab covering a pour opening, a tab sealing
and reformation station comprising a tooling set including upper
and lower tools adapted to close upon a shell with an attached tab,
said upper tool including a reforming surface shaped to define a
taper about the periphery of the pour opening, extending outward
and downward from the pour opening rim, said lower tool including
an anvil surface shaped to conform to said reforming surface, at
least one of said upper and lower tools including a heater.
8. A reforming tooling set as defined in claim 7, further including
heaters in both said reforming surface and said anvil surface, and
a thermocouple in said anvil surface for providing a reference
signal for control of said heaters.
9. A reforming tooling set as defined in claim 7, wherein said
reforming surface is formed of a heat conducting hard rubber
material having sufficient resilience to smooth the foil material
of the tab over the reformed region about the pour opening.
10. A process for converting can end shells into easy open can ends
having a foil type tab covering a pour opening, comprising
providing first and second sets of progressive tooling for working
on end shells, said tooling having cooperating upper and lower
parts and being arranged in successive stations along a
predetermined processing path to form a predetermined pour opening
in the shells with the first tooling set and then to attach a foil
type tab over such pour openings with the second tooling set,
providing a continuous conveyor belt having regularly spaced
openings therein spaced apart corresponding to the spacing of the
tooling stations, said openings extending along at least one lane
longitudinally of the belt, supporting the belt on first and second
drums respectively at opposite ends of the predetermined path to
define upper and lower flights of said conveyor belt, the upper
flight extending though the first and second sets of tooling,
driving the belt around the first and second drums in incremental
steps corresponding to the spacing of the tooling and thereby
moving the upper flight through the first and second sets of
tooling when the tooling parts are opened, providing carrier nests
fitted into the openings in the belt, the nests including an array
of flexible fingers adapted to engage a major extent of the
periphery of a shell to hold the shell therein during conversion
work on the shell as the shell is passed through the tooling,
providing a loading station along the upper belt flight located
between the first drum and the first set of tooling stations,
presenting an end shell to each nest located at the loading station
and placing a presented end shell onto the fingers. providing an
unloading station beyond the second set of tooling whereby each
completed end processed through the tooling sets is removed from
the belt, moving a web of foil tab material in increments over and
across the belt at the location of the first stations of the second
set of tooling to present foil material over a pour opening in each
shell, blanking tabs from the foil material and pressing the
resultant tab onto the shells as a closure to the pour
openings.
11. The method defined in claim 10, including the additional step
of reforming the region of the shell around the pour opening with
the tab in place.
Description
RELATED APPLICATION
[0001] This application is based upon Provisional Application Ser.
No. 60/420,397 filed 22 Oct. 2002 and incorporates the entire
disclosure of that application herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to systems for making unique
container ends, particularly at full production rates, by moving
container shells through progressive conversion tooling wherein the
shells are scored, embossed if desired, formed with a pour opening,
and then securing a foil-like tab sealed to the shell in position
covering the pour opening.
BACKGROUND OF THE INVENTION
[0003] This invention provides a continuous process and apparatus
which converts the can end shells, applies foil-like tabs to the
shells, and discharges the completed ends at commercially viable
speed. Containers, principally metal cans, have been widely used
for packaging liquid beverages, e.g. beer, carbonated drinks,
juices, and the like, which are intended for human consumption.
Many such containers comprise a can formed of a one-piece body and
a fabricated integral easy-open end which is attached across the
open end of a filled can body, as by a roll seal. Such ends have an
integral pour opening defined by a score line which separates
during opening of an attached tab. There are many existing forms of
filling and sealing devices for filling and closing such cans with
artificially or naturally carbonated beverages (e.g. the
bear/beverage market), as well as other drinks or flowable foods
and the like.
[0004] There is also an objection, more prevalent in some
countries, to the "attached pour panel" which in turn was the
result of the ecological objections to its predecessor the "pull
tab" (removable) end. The panel/tab items often were not properly
disposed of. The integral pour opening panel which remains
connected to the container end, is conventionally pushed into the
container, often partly into contents (usually liquid) of the
container.
[0005] There also exist a number of food packaging systems which
place a measured quantity of a food or drink in an open top
container body onto which a foil-like cover is sealed to the top of
the container body; see for example U.S. Pat. No. 5,758,475 issued
2 Jul. 1998, and the prior art cited therein. Such covers can be
formed economically by a simple stamping operation on a foil
supplied from a roll thereof.
[0006] It has been suggested to apply a foil-type cover (or
foil-like tab) onto a formed pour opening in a can end shell,
instead of forming an initially integral pour opening and attaching
an operating tab with the well known integral rivet structure for
severing and opening the pour panel. In such a container end the
shell (in known sizes and shapes) can have a pour opening formed
therein; preferably with a protective rim. The shell is also formed
with a suitable peripheral flange for sealing to the open top of a
can body. Then the end is completed by applying a sealing tab
across the pour opening. The foil-type tab can be easily and
properly thrown away.
[0007] Such an end is disclosed in U.S. Pat. No. 3,312,368, (see
FIGS. 1A, 1B and 1C, Prior Art) which discusses the potential
advantages of such a container end, and also discloses an optional
venting arrangement to relieve internal pressure from the container
before the foil-like tab is removed from the pour opening.
[0008] In addition, U.S. Pat. Nos. 4,397,401 and 4,526,287 disclose
foil tabs for container ends (see FIGS. 2A and 2B, Prior Art)
wherein the rim of the pour opening is formed (e.g. tapered or
projected) toward the outer or public side of the end. If the
attached tab is deformed outward, the stress applied between the
tab and the tapered lip of the pour opening is not a peeling force
but a shear stress, and peeling away of the tab from the pour
opening due to such internal pressure is effectively prevented.
[0009] To the best of applicants' knowledge, at present the
equipment available for continuous manufacture of such ends is
relatively slow and produces the ends at low speed (e.g. three
ends/cycle), and is simply not able to operate at speeds and in
quantities desired for high volume production. Applicants have
determined that such equipment should include the ability to accept
end shells (which are usually made separately), form the pour
opening in each shell, form and attach the foil-type tab over the
pour opening, and seal the tab to the external (public) side of the
resulting end, in one continuous operation.
[0010] An important need of such equipment is the ability to hold
the shells firmly as they are formed and sealed. Precise alignment
of the tabs is important. In particular, there is an important need
to prevent rotation of the shell during the forming and sealing
processes so as not to interfere with alignment of the tabs over
the pour opening. Another need is to provide a sealing apparatus
and method which places the foil securely over the pour opening,
applies the seal, reforms the perimeter of the pour opening with
the tab in place, and allows the seal between the tab and the pour
opening then to set before ends are ready to be discharged and
gathered. A further need is to achieve the most efficient use of
the foil material to minimize the amount of scrap.
[0011] A conveying apparatus, including unique nests, which are
features of a novel converting system for making easy-open can
ends, is disclosed in U.S. Pat. No. 6,405,853 issued 18 Jun. 2002
and its corresponding published Intl. Application No.
PCT/US99/27978 filed 26 Nov. 1999 (both assigned to the assignee of
this application). The present invention includes the incorporation
of this conveying apparatus into a unique system for the
manufacture of the above described foil-tab sealed ends.
SUMMARY OF THE INVENTION
[0012] The preferred transfer conveyor system of the present
invention utilizes a conveyor comprising at least one continuous
belt (in some cases a plurality of such belts operating in
parallel) of reinforced flexible material, with cogs or teeth on
the belt underside. A series of unique and novel nests (see U.S.
Pat. No. 6,405,853) are fitted into holes in the belt at regularly
spaced intervals along the belt(s). The nests are attached at their
opposite edges to the belt(s), which are positively driven and
advance end shells in the nests intermittently through the end
forming tooling and then through the foil-like tab
forming/attaching and finishing equipment of the system.
[0013] The belt(s) are supported by and routed around first and
second drums located beyond the beginning and end of the combined
end shell tooling (for pour opening formation) and the foil-like
tab forming/attaching and finishing stations. In proximity to the
ends of this conveying system are loading (down stacker) mechanisms
and unloading (e.g., up stacker) devices. One or both of the drums
are driven to move the belt(s) step-wise along an upper flight,
such as to advance the nests in predetermined increments, and a
lower or return flight.
[0014] The progressive end conversion tooling for shaping the
shells into container ends, with formed and finished pour openings,
is located in the mouth or entrance of the press, and the belt(s)
passes the nests and shells therein between the upper and lower
conversion tooling sets.
[0015] The tab forming and application tooling is preferably
located beyond the conversion tooling but principally within the
boundaries of the mouth of the same press. A supply web of foil
material is fed step-wise across the conveyor(s) at the forming and
application station. A blanking apparatus at each of the
application locations acts to create and to separate (e.g. die cut)
tabs from the foil and tack the tabs against the shells, covering
the pour openings. The tabs are then heat sealed over the pour
opening. The tab area around the pour opening rolled perimeter,
with the foil-tab attached, may then be re-formed to provide a
surface sloping slightly downward and away from the pour opening to
enhance adhesion of the tabs to the shells in that region, using
unique tooling disclosed hereafter.
[0016] Other objects and advantages of the invention will be
apparent from the following description, the accompanying drawings
and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIGS. 1A, 1B and 1C are views from the prior art of a
foil-type tab applied to a container end shell.
[0018] FIGS. 2A and 2B are views from the prior art illustrating
details of a bonded interface between a foil-type tab and a shell
surface about the pour opening.
[0019] FIGS. 3A and 3B are views of another design of foil tab and
of a related end shell with the tab applied and the covered pour
opening indicated in dotted lines.
[0020] FIG. 4 is a plan view of the system including portions of
the conveyor drive, with the end tooling, the foil supply, and the
tab application equipment shown schematically.
[0021] FIG. 5 is an abbreviated side view of the press and conveyor
system, with some parts shown schematically.
[0022] FIG. 6 is an abbreviated view of the rear of the press.
[0023] FIG. 7 is an enlarged plan view of a segment of the top
flight of one three lane belt, including attached nests for
carrying end shells as they are converted into ends.
[0024] FIG. 8 is a partial plan view of a lifter pad for the
transfer belts, located in the region where the belts traverse the
various tooling stations.
[0025] FIGS. 9, 10 and 11 are top and cross-sectional views of a
nest as disclosed in U.S. Pat. No. 6,405,853, with an end shell
located in the nest in FIG. 11.
[0026] FIG. 12 is an enlarged plan view of a segment of the top
flight of one three-lane belt (which would moved upwardly in the
view), showing the stations of three lanes of end conversion
tooling, and the entry to the following tab operations
stations.
[0027] FIG. 13 is an enlarged plan view of a further segment
(continuing upward from FIG. 12) of the same three lane belt and a
progression of corresponding tab forming and application
stations.
[0028] FIGS. 14A-E are cross-section views taken through the
progression of the formed end shells at the stations shown in FIG.
12.
[0029] FIG. 15 is an enlarged top plan view showing segments of
four three lane belts, the foil feeding and embossing, tab cutting
and forming and tab application stations, and foil skeleton
removal.
[0030] FIG. 16 is a substantially enlarged segmental view of the
layout of tabs on the foil.
[0031] FIGS. 17A, 17B, 17C are three partial cross-section views
through three stations of the tab forming and tacking stations
showing their progression.
[0032] FIG. 18 is a schematic plan view taken across the foil
feeding and tab forming and applying stations.
[0033] FIG. 19 is an enlarged partial end view of one of the plates
shown in FIG. 18, with the foil engaging bar raised.
[0034] FIG. 20 is an enlarged partial end view, similar to FIG. 19,
showing the foil engaging bar contacting one edge of the foil.
[0035] FIG. 21 is a partial side view of the plate and foil
engaging bar.
[0036] FIG. 22 is an enlarged cross-section view of one set of the
tools at a tab forming and tacking station.
[0037] FIG. 23 is a perspective frontal view of one set of the
upper tab heat sealing and reforming tools.
[0038] FIG. 24 is a plan view of the face of one of the lower tab
heat sealing and flanging lower tools.
[0039] FIGS. 25 and 26 are, respectively, enlarged open and closed
cross-section views of the tooling at one of the heat sealing and
reforming stations.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Ends with Preformed Pour Openings and Foil-Type Tabs
[0040] Referring to FIGS. 1A, and 1B (Prior Art), it has been known
for many years to apply a foil-type cover (or tab) 13 onto a pour
opening 12 formed in a can end shell 11 which may be of aluminum,
lightweight tin plate, or conventional tin plate. Such an end and
removable tab (termed a peel tab) is disclosed in U.S. Pat. No.
3,312,368, as mentioned above. The pour opening 12 preferably has a
rim including a protective coating. The tab 13 includes a sealing
portion across the pour opening and a free end 16 to grasp in
removing the tab. A preferable tab is light gauge (.about.0.009
inch) aluminum. Shell 11 may also be formed with a suitable
peripheral flange for sealing to the open top of a can body.
[0041] The container end described therein is intended for use with
liquid contents under pressure, and may also have an optional
venting arrangement (FIG. 1C) comprising a separate opening 12V in
the end covered by part of a tab and opened as the tab is removed
to relieve internal pressure from the container.
[0042] U.S. Pat. No. 3,547,305 discloses forming an upward curl
about the rim of a pour opening. U.S. Pat. No. 4,526,287 discloses
foil tabs for container ends (see FIGS. 2A and 2B, Prior Art) in
one form of which the rim 17 of the pour opening is formed (e.g.
tapered or projected) toward the outer or public side of the end,
preferably at an angle of 151 to 301. As stated in that patent, if
the attached tab is slightly deformed outward the stress applied
between the tab and the tapered lip of the pour opening is not a
peeling force but a shear stress, with the result that accidental
peeling away of the bonded portion of the tab, especially around
the pour opening, is effectively inhibited.
[0043] This prior art also points out that the shape of the pour
opening can be freely changed; for example, circular, ellipsoidal,
egg-like, rain drop-like, oval, or gourd-like openings can be used,
and they can be formed in various sizes of end shells. The system
of the present invention can readily accommodate such size and/or
shape changes. For purposes of the present description, a shell 20
with a somewhat rounded triangular pour opening 22, provided with a
rolled rim 23, and fitted with a foil tab 25, is shown in FIG. 3B.
The tab itself is shown in FIG. 3A. The tab includes a central area
26 covering pour opening 22, a frontal or forward area 27, and a
handle or operating extension 28 having a ruffled embossed area to
provide an enhanced grip. The area 29 surrounding the pour opening
and nearby portions of tab 25 is preferably tapered upward similar
to the showing in FIG. 2B.
System Layout
[0044] FIGS. 4, 5 and 6 show the overall configuration of an end
building system in accordance with the invention, including a
reciprocating press apparatus. Such a press may have a capacity in
the order of 350 Tons (U.S.), operating at 150 to 170 strokes/min.
A typical such press is a Minster Model E2 HF-350 available from
Minster Machine Company, Inc. of Minster, Ohio, U.S.A.
[0045] The press includes a bed B, a crown C supported upon side
frames which include multiple posts P extending upward from bed B,
and a vertically reciprocating ram R which is guided in its
vertical motion by posts P. The crown C houses a motor driven
crankshaft CR fitted with crank-rods or links (not shown) attached
to ram R. The space between ram R and bed B defines the mouth of
the press, usually of rectangular shape, and multi-station
progressive tooling is mounted to the underside of ram R and the
top of bed B to cooperate in performing successive operations upon
can end shells as the shells are advanced in increments from one
station to the next, from front to back (in the illustrated
embodiment) through the press.
[0046] Upper and lower tooling sets for working on the shells to
define and form a pour opening, and defining and applying foil-type
tabs, indicated by the general reference numerals 30 and 31, are
mounted to ram R and on bed B, respectively. The tooling sets 30
and 31 are divided approximately equally between the front half and
rear half of the press mouth. The upper tools are fitted to a punch
plate 35A which-in turn is supported on ram R, and lower tools are
fitted to a bed plate 35B on the press bolster or base B.
[0047] Crankshaft C is fitted with a power take-off pulley 38. FIG.
6 shows a belt 40 which transfers power from crank pulley 38 which
is connected to a drive shaft 45. Shaft 45 (see FIG. 6) may be
connected through a right angle drive 48 to an intermittent drive
unit 50, of conventional construction, which drives the conveyor,
and to servomotor drives SM-1 and SM-2 for foil feeding
equipment.
Conveyor
[0048] The system provided by this invention uses a nest-type
conveyor system as disclosed in said U.S. Pat. No. 6,405,853. It
includes the intermittent drive unit 50 connected to a shaft 53
supported at the rear of the press (FIG. 6) in outboard bearings 54
and carrying first drum(s) 55A-55D which are rotated together in
timed intermittent fashion, synchronized with the rotation of the
crank C and motion of press ram R. The conveyor belt(s) 60 move
forward through the press mouth when the press is open (e.g. the
ram is up) in increments which match the spacing of the stations
within the tool sets.
[0049] At the front of the press, outboard of the press frame and
posts P, second drum(s) 57A-57D (FIGS. 4, 5 and 6) are supported in
suitable bearings 58. Drum(s) 57A-57D may optionally also be driven
by drive unit 50. Extending between each set of drums 55A-D and
57A-D are endless conveyer belts 60A-60D (in a preferred embodiment
there are multiple such belts operating in parallel) fitted with
integral drive teeth 61 on their undersides(see FIG. 7). The
illustrated embodiment employs four such belts 60A, 60B, 60C and
60D, each with three lanes, to provide a total of twelve lanes
I-XII for a 12-out system (FIG. 4). One or more tensioning devices
83 urge drum 57 in a direction away from drum 55, maintaining
tension in the belt, particularly along upper flight 60UF. It
should be understood that various numbers of belts, each with one
or more lanes of nests, are within the purview of this invention.
The system disclosed herein uses four such belts, as explained
hereinafter.
[0050] The belts 60A-60D extend front to back of the press and each
belt is of the `endless` type, with the toothed underside passing
about the two drum sets 55A-55D and 57A-57D and their drive teeth,
forming an upper or active flight 60UF and a lower return flight
60LF. Each belt also is provided with multiple rows or lanes (e.g.
three lanes I, II and im in belt 60A, etc.) of openings 62 (FIG. 7)
which are regularly spaced to correspond to the spacing of the
centers of the tooling stations. In these openings are nests 65 of
a diameter such that ears 66 on the nests overlap the edge of the
openings 62 (FIGS. 7 and 15).
[0051] The nests 65 are relatively light weight and preferably are
rigid molded plastic parts, which are placed in openings 62 along
the lanes in each belt and attached to the belt by pins 67 through
ears 66 (FIGS. 6, 7 and 10), aligned transversely of the path of
travel (e.g. length) of the belts. Thus shells deposited in the
nests are carried through the tooling 30 and 32, in intermittent or
step-wise fashion, synchronized to the operating strokes of the
press.
[0052] Shells S to be converted are loaded onto belt 60 at the
loading station indicated by general reference numeral 68 in FIGS.
5 and 6. Completed shells which have a pour opening of chosen
configuration, and have a tab sealed over such pour opening, are
unloaded from the nests at or beyond the rear of the press.
[0053] The shell loading mechanisms are also referred to in the art
as a down-stacker mechanism, in reference to the manner in which it
takes single shells from the bottom of a supply stack and places a
single shell S into each nest 65 at the loading station 68. The
shell loading mechanisms 66 are located on the press (FIG. 5)
outboard of posts 12 and 14. These mechanisms are per se known; see
U.S. Pat. No. 6,405,853.
[0054] There are multiple down-stacker mechanisms, each designated
by the general reference numeral 65, one each of which (FIGS. 4 and
5) is mounted over the conveyor lanes I-XII. Base plate 67 holds
these mechanisms, and is mounted over conveyor belts 60A-D, outside
of the press frame. A bottom plate 68, to which the base plate is
bolted, includes vacuum chamber 78 (FIG. 1) to which a vacuum hose
fitting is attached from a suitable source of vacuum VB. Plates 67
and 68 are recessed to define shallow passageways 70 receiving the
conveyor belts 60A-D.
[0055] Above chamber 78 there are circular feed openings of a
diameter just large enough to pass the shells S which descend from
a stack thereof contained within guide rods. The lowermost shell S
has its lip supported on the feeding threads of three feed screws
spaced around each feed opening such that one full rotation of
these screws will carry the lowermost shell from the stack and
deposit the shell in a nest 65 located beneath the feed opening.
The power and timing for the feed screw rotation is derived from a
belt which is driven from power take-off shaft section 45 as
earlier described. By proper selection of pulley sizes and gear
sizes, teeth numbers, and ratios, the intermittent rotation of the
shaft is translated into 360.degree. rotations of feed screws, and
a single shell is deposited in a nest 65 as those openings halt
under the feed opening.
[0056] In the system as illustrated, twelve series of ring shaped
nests 65 (preferably circular) are arrayed in lanes I-XII, along
the four flexible conveyor belts 60A-D, e.g. three lanes per belt.
Nests 65 have an underside (FIGS. 10 and 11) resting on the belts
60A-D at the edge of openings 62 to define the vertical or height
dimension of the nests in the belt. The nests have a rim 74 which
is fitted into the corresponding opening 62. Independently flexible
gripping fingers 75, which are integral to rim 74 through flexible
arms 73, present a discontinuous ledge 76 through which the curl C
of an end shell S initially passes (FIG. 11).
[0057] A shell is placed into a nest ring by moving the shell with
curl C upward and its central panel P and chuck wall CW facing
downward (see FIG. 14). The curl is pulled through the inward and
downward tapered fingers 75 and onto the lower rim. The bottom of
the shell, including the lower end of its chuck wall CW and the
central panel P, is then located at the lower edge of the nest with
curl C between the lower rim surface 71 and fingers 75 as explained
in U.S. Pat. No. 6,405,853.
[0058] Fingers 75 are somewhat opened in a radially outward
direction during this process, and then close inward entirely
around and over the shell curl C, so as to exert a centering force
on the shell as it is loaded into the nest, and to hold it securely
about its entire periphery. This retains the shell especially
against turning as the shell progresses through the tooling
stations while various operations are performed on it and a tab is
attached to it.
[0059] The shells are snapped in place and firmly held by insertion
assemblies 85 of like construction, each including an insertion
head 85H which has its lower face shaped to conform generally to
the inner upper surface of a shell placed in a nest. These
insertion heads are arranged to push a shell positively into
engagement with the internal teeth of each nest, one station (drive
step) before the shell passes into the tooling; see U.S. Pat. No.
6,405,853.
[0060] The attachments between nests 65 and belt 60 allow for
limited controlled relative movement of the nests, but only in
directions tangent to the turns of the belt about the drums, thus
the nests remain flat about the turns and can carry parts (the
shells and resultant ends) about drum 55 from the upper to the
lower belt flights.
[0061] The upper flight 60UL of the belts is lifted upward by
spring biased lifter pads 84 (FIG. 8) when the press is opened, and
the belts and attached nests 20 are moved incrementally forward
over the lifter pads, to locate nests 65 successively in alignment
with the progressive tooling stations. This is disclosed in said
U.S. Pat. No. 6,405,853.
[0062] FIGS. 6 and 12 illustrate general details of the upper and
lower tooling sets 30, 31. The punch holder plate 35A is fastened
to the bottom surface of the ram R, and a base plate 35B is
supported below, in the space between the flights of belt 60.
[0063] Thus, shells placed in the conveyor nests are carried
progressively to the succeeding stations of the shell conversion
tooling by each step-wise movement of the conveyor. When the press
opens (ram rises) conveyor 60 is indexed (left to right in FIG. 5).
Preceding conveyor motion, the stripper pad(s) 84 (FIG. 8) is
raised to guide the conveyor above the die tools. The conveyor
belt(s) 60A-60D are taut in the upper flights 60UF and level across
the lifter pads. In this position the belts advance only after the
lift movement has stopped. The shell converting path thus defined
extends from side to side of the press and the conversion tool
stations (along with the tab forming and sealing stations described
below) are laid out on the die shoe and punch holder plate in such
fashion that they are generally symmetrically disposed with respect
to the front to back center lines of the press so as to distribute
loads over the press mouth. As further described below, foil tab
forming and attaching stations IT-XIIT are arrayed along belts 60
beyond the location of the shell conversion tools (FIG. 4).
[0064] Details of the face tools in the individual punches and dies
are not shown since these are not necessary for an understanding of
the present invention and will vary with the design of a particular
pour opening and tab. The sequence of the shell conversion
operations are illustrated in FIG. 12 and the cross-sections of the
progressively formed shells are shown in FIGS. 14A-14E. Basically,
a shell is formed with a pour opening of predetermined shape, and
the edge or perimeter of such opening is provided with a rolled
configuration to avoid a sharp edge around the pour opening, for
example in case a user desired to drink directly from the pour
opening
[0065] Thus, as particularly shown in FIGS. 12 and 13, the stations
of the shell conversion tooling, along with the conveyor, define
side-by-side shell conversion paths, the final ones of which are
approximately midway of the lengths of the paths. At that location
a relatively wide foil strip FS is guided and advanced,
step-by-step in a side-to-side direction across the belts. In this
area the tabs are formed (cut) from the foil strip FS and tacked to
the shells, extending over the pour openings. The skeleton remains
of the foil are moved away past the far side of the last belt 60D,
and may be chopped into fragments suitable for scrap disposal such
as shown at the right end of FIG. 15 (labeled Foil Scrap
Chopper).
Tab Tooling and Tab Attachment
[0066] As previously mentioned the tabs are formed from a strip of
aluminum foil or like material. In the embodiment shown in the
drawings the relatively wide (e.g. about 13 inches wide) foil strip
FS is supplied from a roll RFS mounted on one side of the press
mouth and directed along a tab forming and application path 70
which is transverse to the path of belts 60. This foil strip
encompasses the twelve tab paths for supplying tabs to each shell
in the lanes I-XII. The downward facing side of the foil has a heat
sensitive adhesive (normally dry) applied to it. The edges of strip
FS slide along, and are supported on, spaced apart rails 72. Strip
FS is moved along path 70 in steps as the strip traverses across
the paths of belts 60, through the first set of tab forming and
application tooling stations (see FIGS. 13 and 18). The step
increment is determined by the length of the chosen tab (which in
this case is the tab illustrated in FIG. 3A), the tab orientation
as it is formed from the foil strip FS, and the spacing between
successive ones of the tab forming and application stations across
the belts 60. The tab forming and applying stations IT-XIIT are
arrayed in an echelon fashion (FIGS. 4, 13 and 15) at the
intersections of the lanes and the tab paths as later
described.
[0067] The tab design is chosen to maximize usage of the foil. As
part of the specific design disclosed, the tooling in related
stations across the conveyor belts is reversed by 1801 such that
the formation of the pour opening is on opposite sides of the
centerline of the end shell lengthwise of the belts. This layout is
apparent in FIGS. 12, 13 and 15. In the three rows of belt 60A, the
tabs 25 have their forward areas 27 to the left in the lanes I and
III, and to the right in lane II. This alternate relationship of
the tooling is carried through the several belts in a system. The
outline of removed tab material shown in FIGS. 13 and 16
demonstrates this layout of the tabs along the twelve paths
lengthwise of foil strip FS. Nesting of the tab shapes, facing
first to the left, then to the right, is apparent from this
drawing. The remains or skeleton of the foil strip can be seen in
FIGS. 15 and 16, which shows an enlarged segment of the strip just
past lane XII. The shadowed areas of the tabs 25 represent removed
foil openings, leaving relatively thin connections between
openings.
[0068] FIGS. 13 and 15 show the feed increment of the foil strip
FS, with small cross-hair (+) marks in FIG. 15 identifying the
center point of each tab 25 aligned over the pour openings of the
shells. Thus, in FIG. 15, the first tab formed from strip FS is
over the lane I tab forming and applying tools. The outlines of
tabs across the lowermost tab paths illustrate the progress of the
skeletal remains of the foil. The increment of foil feeding is
equal to about 12 times the lengths of tabs 25 as measured along
the foil strip. The tab forming and applying tooling sets (see FIG.
22 for details) are identified broadly as I-T through XII-T and are
arranged in a step-like (echelon) fashion across the lanes I-XII as
shown in FIGS. 4 and 15). The center-lines of this tooling are
located in the respective lanes at their intersections with the
twelve paths along the foil strip from which the tabs are
formed.
[0069] The step-by-step movement of strip FS is precisely
controlled by a set of four movable frames 75A, 75B, 75C and 75D
(FIG. 18) which are each the approximate width of a belt, and which
confine the strip edges close to guide rails 72. These rails may be
L-shaped in cross-section, having a horizontal leg 73 and a
vertical leg 74. Frames 75A-D have side rollers 78 (FIGS. 19 and
20) which support the frames for limited movement along the
vertical rail legs 74. The frames each have presser bars 77 fitted
into their opposite sides (along the foil path) and are moved
between retracted or raised positions (flush with the plates' lower
surfaces) and extended positions in which the presser bars contact
narrow areas along the edges of foil strip FS. This up-down motion
of the presser bars is controlled by small pneumatic piston devices
79 mounted in the frames. When bars 77 are raised, the
corresponding frames will pass freely over the foil edges; when the
bars are extended they will press a length of the foil strip edge
(equal to the bar's length) against the guide rails and push the
strip forward by the predetermined increment.
[0070] The frames 75A-75D each have apertures 80 formed therein
which provide access for the tab forming and applying tooling from
above and below the frames. These apertures are sized and shaped to
surround the various sets of tool at each of the stations T-I . . .
T-XII whether the plates are in their respective advanced or
retracted (alternate) foil indexing positions, so the tooling sets
can function at each stroke of the press ram. Thus, while the
frames accomplish the foil feeding incremental motion, moving
alternately as described above, they maintain clearance at all
times for the tab forming and applying tooling and related
mechanisms.
[0071] Referring to FIG. 18, the frames 75A and 75C are connected
for joint motion by one or more struts 82, and frames 75B and 75D
are similarly connected by one or more struts 83. These two sets of
frames are independently movable, such that either set can advance
strip FS independently of the other set, so long as the presser
bars of the other set are raised. The reason for this alternate
dual motion relates to the relatively large mass of the plates, and
the short time available for this movement during a press
cycle.
[0072] Thus, each connected set of frames 75A and 75C, and 75B and
75D, will alternate in engaging edge portions of strip FS and are
cycled such that the strip FS is moved along path 70 first by one
set (with presser bars engaged) for one feed increment, while the
other set of frames has its presser bars raised (released). The
intermittent timed drives for this movement are provided by the
servomotors SM-1 and SM-2. It follows that at all times some of the
presser bars are extended against the foil strip edges and keep the
strip taut during and between the intermittent strip feeding
action. During this intermittent incremental feeding action strip
FS is guided by the upward extending legs 73 on the edges of rails
72 to keep foil strip aligned as it is moved step-wise along its
path 70, all the way through the various tab application stations
I-T, II-T . . . IIX-T (etc.), toward the opposite side of the
press. Details and function of these stations are explained
hereinafter. Once the depleted (all tabs removed and placed) strip
FS moves beyond that last application station, the scrap skeleton
remains of the strip (FIGS. 15 and 16) may be cut into suitable
pieces in a scrap chopper 80 actuated during each press stroke, and
the pieces are discharged.
[0073] Referring to FIGS. 15 and 17, at each of the tab forming and
applying stations there is a set of upper and lower tooling as
shown in FIGS. 17A, 17B and 17C and in FIG. 22. The lower tooling
comprises essentially an anvil 80 which engages the underside of a
shell, with its pour opening aligned as previously explained,
within a nest, and supports the shell as a tab is applied onto its
upper surface, covering the pour opening.
[0074] The upper tooling comprises an outer die cutting member 82,
with an internal cut edge 83 shaped to the desired external
configuration of a tab 25, and a reciprocating cutter 84 with an
external cut edge 85. Within cutter 84 is a placer probe 87 which
is extendable from the cutter and includes a passage 88 to which a
vacuum can be selectively applied. Within placer probe 88 there is
a tacking probe 90, which is heated by an appropriate electric
heating element 92
[0075] The sequence of forming and applying a tab is illustrated in
FIGS. 17A, 17B and 17C. As the press closes, the foil is held
across the die cutting members 82 at each of the stations, and the
cut edge 85 of the reciprocating cutter 84 passes through cut edge
83, separating a tab from the foil. Placer probe 87 contacts the
tab, with the vacuum switched on, and carries the tab into contact
with the shell below, covering the pour opening. In the tab
embodiment shown the tail of the tab extends over the edge of the
shell. Pressure against the adhesive on the lower surface of the
tab against the shell is sufficient to initiate tacking the tab in
position. The tacking probe 90 descends with placer probe 87
against a small area of the tab and forms a heat seal which will
hold the tab in place on the shell for further operations.
[0076] As the press then opens, one of the frames performs a
sequence of advancing the foil strip FS by one increment to prepare
for the next forming and placing of a tab at each of the stations
IT-XII-T and the belts are indexed to bring the next set of nests
into alignment with the tab forming and placing stations. During
the next press cycle, the other frame performs the foil advancing
sequence. However, one of the frames is always holding the foil
whenever an advancing sequence is not being performed.
[0077] Following are charts explaining the timing of the increment
feeding movements of the frames. TABLE-US-00001 Foil Blank,
Transfer to Shell Press Crank .degree.Rotation Function 0 (TDC)
[Start] 106 Sect. 1 stripper indexed into start position, vacuum on
118 Foil blanked out, transfer punch air on 170 Transfer punch
extended, vacuum off 180 (BDC) Foil heated, tacked to shell 190
Transfer punch retracts 242 Blank punch clears bridge, Sect. 2
stripper clamps foil 248 Section 1 stripper releases 254 Sect. 2
stripper begins next index and Sect. 1 stripper returns to start
position 360/0 (next TDC) 106 Sect.2 stripper indexed into position
118 Foil blanked out, transfer punch air on 170 Transfer punch
extended 180 Foil heated, tacked to shell 190 Transfer punch
retracts 242 Blank punch clear bridge, Sect. 1 stripper clamps foil
248 Sect. 2 stripper releases 254 Sect. 1 stripper begins next
index, Sect. 2 stripper returns to start
Tab Sealing and Reformation
[0078] As the shells with tabs 25 attached are advanced they reach
sets of tooling I-R-XII-R which reform the pour opening area of the
shells and the tabs thereon. The details of this tooling are
illustrated in FIGS. 23-26. One of the upper tools is shown in
FIGS. 23, 25 and 26, including a punch 100 with a reforming surface
102 shaped to define a taper about the periphery of the pour
opening, extending outward and slightly downward from the pour
opening rim. The shape of the pour opening is, in the described
embodiment, a triangle with rounded corners, the base of such
triangle being adjacent the perimeter of the shell. Adjacent but
spaced from the apex of the pour opening reforming surface 102,
near the center of the shell, is a bar formation 104 with rounded
edges, which acts similarly to a coining tool to concentrate heat
onto the forward area 27 of the tab 25 (FIG. 3B) at the edge of the
shell opposite the pour opening. The purpose of this is to make an
especially firm bond of the tab to the shell which discourages
pulling the tab totally from the shell when the tab is opened. The
upper tool includes a small electric heater 105.
[0079] The lower reforming tool 110 (FIGS. 24, 25 and 26) includes
an anvil-like surface 112 shaped to conform with upper tool surface
102, to press the combined shell and tab when the tools close and
form an upwardly sloping area 113 about the pour opening and
stretch the tab in that area as it is firmly heat sealed to the
shell. The lower tools also have a bar formation 114, complementary
to upper tool bar 104, and a separate electric heater 115, along
with a thermocouple 116 to provide a reference for the control for
heaters 105 and 115.
[0080] While metal faces for the reforming tool surfaces 102 have
been satisfactory, better results have been observed by providing
the face portion of the upper tool(s) as a heat conducting hard
rubber which has sufficient resilience to smooth the foil of the
tab without tearing it as the tools close during a press cycle,
thereby providing a uniform bonding of the tabs over and around the
pour openings and the surrounding shell surface.
[0081] FIGS. 25 and 26 show a cross-section through one station of
the reforming tooling, including a nest with a shell between them
(the adjoining portions of belt(s) 60 is omitted). FIG. 25 shows
the tools open, and FIG. 26 shows them closed. Heat can be applied
to the reforming tools from approximately 661 after TDC for
approximately 2881 (or 661 before TDC) of the press cycle.
[0082] There may optionally be one or more idle station positions
along the belts 60A-60D after the reforming stations, to allow time
for cooling and setting of the heated tabs sealed to the shells.
The finished ends can be removed from the nest with conventional
upstacker mechanisms (not shown) or can be carried in nests 65
around the drums 57 into the beginning of the return flights 60LF.
In the latter case, a knock-out device, extending into the space
between the belt flights 60UF and 60LF, includes brackets 170
attached to press ram R (FIGS. 5 and 7). Knock-out rings 172 on the
brackets are positioned such that when ram R descends, finished
ends are ejected downward from the downward facing nests onto
chutes where they are pushed by air streams (e.g. from compressed
air pipes) to the end of the chutes.
[0083] While the methods herein described, and the forms of
apparatus for carrying these methods into effect, constitute
preferred embodiments of this invention, it is to be understood
that the invention is not limited to these precise methods and
forms of apparatus, and that changes may be made in either without
departing from the scope of the invention.
* * * * *